EP4375593A1

EP4375593A1 - Ice-making device and ice-making method

Info

Publication number: EP4375593A1
Application number: EP22845815.4A
Authority: EP
Inventors: Yoshio HIROKANE
Original assignee: Blanctec International Co Ltd
Current assignee: Blanctec International Co Ltd
Priority date: 2021-07-20
Filing date: 2022-07-12
Publication date: 2024-05-29
Also published as: WO2023002881A1

Abstract

Provided is an ice-making device that can be easily miniaturized. The ice-making device includes: a freezing tank 12 that stores brine; and a flake ice making part 15 arranged inside the freezing tank 12 and capable of being immersed in the brine Ws, wherein the flake ice making part 15 includes: a disc part 26 that causes a refrigerant, which is supplied from a freezing machine 14, to circulate therein, the disc part 26 having plate surfaces 26a, 26b that generate ice of the brine Ws; a nozzle part 41 that provides a flow of the brine Ws to the plate surfaces 26a, 26b; and a sweeping part 23 that is displaced with respect to the plate surfaces 26a, 26b to separate the ice generated on the plate surfaces 26a, 26b from the plate surfaces 26a, 26b.

Description

Technical Field

The present invention relates to, for example, an ice-making device with a metal ice-making body, an ice-making device for producing flake ice, etc., used in ice slurry, and an ice-making method for producing flake ice, etc.

Background Art

For example, fresh foods such as seafood, shellfish, and meat are generally frozen as frozen products, and these frozen products are generally stored or transported. Ice slurry is used to freeze the items to be frozen, and the items to be frozen are immersed in the ice slurry and instantly frozen to maintain the freshness of the ingredients. In the invention disclosed in Patent Document 1 below, ice slurry is produced by dropping flake ice (ice fragments) from an ice slurry material production device (200) into an ice storage tank (500). The ice slurry in the ice storage tank (500) is supplied to a freezing device (6) via an ice slurry supply tube (45).
For example, flake ice (lamellate ice) production devices, as disclosed in Patent Document 2 and Patent Document 3 below, are also known. These flake ice production devices are provided with ice-making plates made of metal (also referred to as "metal ice-making plates", "metal plates", and "ice-making bodies"). An ice-making plate made of metal is used for producing flake ice and ice slurry by freezing an aqueous solution of a solute such as common salt, calcium chloride, or ethanol.
For the ice-making plates, there are mainly plate-type ones and drum-type ones. The ice-making plates are made of metal materials such as iron, stainless steel, aluminum, copper, etc., and surface treatment such as electroless nickel plating or chrome plating are applied thereto.
The ice-making plate includes a refrigerant path that is connected to the freezing machine and circulates refrigerant gas inside thereof. For the refrigerant path, various measures are taken to increase the fluidity of the refrigerant gas to secure the freezing capacity. For example, paragraph [0051] of Patent Document 2 describes that the refrigerant flows down while circling. Paragraphs [0037] and [0058] of Patent Document 3 describe the formation of curved portions in the refrigerant flow path.
The ice-making plate in Patent Document 2 employs a drum-type configuration similar to the ice slurry material production device (200) disclosed in Patent Document 1. In Patent Document 3, a plate-type configuration with a flat-plate shape is adopted for the ice-making plate.

Citation List

Patent Literature

Patent Document 1: Japanese Patent Application Laid-Open Publication No. 2019-207046
Patent Document 2: Japanese Patent Application Laid-Open Publication No. 2019-143905
Patent Document 3: Japanese Patent Application Laid-Open Publication No. 2019-143906

Summary of Invention

Technical Problem

In the technical field of freezing devices and freezing methods, there are needs for even better technology for freezing. Each of the disclosure modes of the present invention is to provide better ice-making device and ice-making method than before.

In the conventional ice slurry production device (200) and freezing system as disclosed in Patent Document 1, the ice slurry material production device (200) was installed on the ice storage tank (500), and ice slurry was supplied from the ice storage tank (500) to the freezing device (6) via the ice slurry supply tube (45). Therefore, the ice slurry production device and freezing system tend to be larger, and it is not easy to downsize thereof.
The challenge of the invention related to the first disclosure mode is to provide an ice-making device (also referred to as "ice slurry production device") that is easy to miniaturize.

When further improvement of freezing capacity in the flake ice production device or ice slurry production device is considered, it is necessary not only to increase the fluidity of the refrigerant but also to consider other matters. Therefore, as for the freezing capacity, the inventors focused not only on the fluidity of the refrigerant, but also on the heat transfer between the refrigerant path and the refrigerant. Then, even if the fluidity of the refrigerant declines to some extent, the inventors believed that good heat transfer was able to improve the overall freezing capacity.
The challenge of the invention related to the second disclosure mode is to provide an ice-making device and ice-making method with high freezing capacity.

Further improvement of freezing capacity is desired for the ice slurry production device 1 as disclosed in Patent Document 1 and the flake ice production devices as disclosed in Patent Document 2 and Patent Document 3. To improve the freezing capacity, it can be considered to increase the fluidity of the refrigerant. However, it is not easy to dramatically improve the freezing capacity by increasing the fluidity of the refrigerant.
The challenge of the invention related to the third disclosure mode is to provide an ice-making device and ice-making method with high freezing capacity.

It is necessary to manufacture the ice slurry and ice (hereinafter referred to as "ice slurry, etc.") in advance for various types of ice-making devices such as the ice slurry production device as disclosed in Patent Document 1 and the flake ice production devices as disclosed in Patent Document 2 and Patent Document 3. If there is a malfunction in the ice-making device, it will be impossible to manufacture the ice slurry, etc. in advance, and it will be impossible to meet the demand for the ice slurry, etc. Therefore, high reliability is required for these ice-making devices.
The challenge of the invention related to the fourth disclosure mode is to provide an ice-making device and ice-making method with high reliability.

Solution to Problem

According to each of the disclosure modes of the present invention, it is possible to provide superior ice-making device and ice-making method.

(1) In order to solve the above problem, the invention related to the first disclosure mode is an ice-making device including: an ice slurry production tank storing brine; and an ice production unit arranged inside the ice slurry production tank, the ice production unit being able to be immersed in the brine, wherein the ice production unit includes: an ice-making plate circulating refrigerant, which is supplied by a freezing machine, inside thereof and including an ice-making surface, which generates ice of the brine on at least one surface thereof; a flow forming unit providing a flow of the brine to the ice-making surface; and a sweeping unit being displaced with respect to the ice-making surface to separate ice generated on the ice-making surface from the ice-making surface.
(2) In order to solve the above problem, another invention is the ice-making device described in (1) above, wherein the sweeping unit is arranged in a driving unit that rotating or rotatively reciprocating with respect to the ice-making surface.
(3) In order to solve the above problem, another invention is the ice-making device described in (1) or (2) above, further including a holding unit holding at least the ice-making plate and the driving unit in one piece.

To solve the above problem, the invention related to the second disclosure mode is an ice-making device including: a metal body in which a refrigerant flow path is formed, wherein an asperity portion is formed on a flow path surface of the refrigerant flow path.

(1) In order to solve the above problem, the invention related to the third disclosure mode is an ice-making device including: an ice-making unit contacting brine; a first refrigerant path formed to pass through the ice-making unit and capable of causing a first refrigerant to flow; and a second refrigerant path formed to pass through the ice-making unit and capable of causing a second refrigerant, which has an evaporation temperature lower than an evaporation temperature of the first refrigerant, to flow, wherein the second refrigerant cools the ice-making unit cooled by the first refrigerant.
(2) In addition, in order to solve the above problem, the third disclosure mode is an ice-making method including: after passing a first refrigerant through an ice-making unit contacting brine to cool the ice-making unit, switching the first refrigerant to a second refrigerant having an evaporation temperature lower than an evaporation temperature of the first refrigerant; and cooling the ice-making unit, which has been cooled by the first refrigerant, by the second refrigerant.
(3) In addition, in order to solve the above problem, the third disclosure mode is an ice-making method performed using an ice-making device including an ice-making unit contacting brine, a first refrigerant path formed to pass through the ice-making unit and capable of causing a first refrigerant to flow, and a second refrigerant path formed to pass through the ice-making unit and capable of causing a second refrigerant, which has an evaporation temperature lower than an evaporation temperature of the first refrigerant, to flow, the ice-making method including: cooling the ice-making unit by the second refrigerant after cooling the ice-making unit by the first refrigerant.

In order to solve the above problem, the invention related to the fourth disclosure mode relates to the following ice-making device and ice-making method.

(1) An ice-making device including: an ice slurry production tank storing brine; and an ice production unit arranged inside the ice slurry production tank, the ice production unit being able to contact the brine, wherein the ice production unit includes: an ice-making plate having an ice-making surface; and a sweeping unit being displaced with respect to the ice-making surface to separate ice generated on the ice-making surface from the ice-making surface, wherein at least part of the sweeping unit has water-repellent coating.
(2) An ice-making method using the ice-making device described in (1) above.

Advantageous Effects of Invention

According to each of the disclosure modes of the present invention, it is possible to provide superior ice-making device and ice-making method.
According to the first disclosure mode, it is possible to provide an ice-making device that is easy to miniaturize.
According to the second disclosure mode or the third disclosure mode, it is possible to provide an ice-making device and ice-making method with high freezing capacity.
According to the fourth disclosure mode, it is possible to provide an ice-making device and ice-making method with high reliability.

Brief Description of the Drawings

FIG. 1 is a perspective view schematically showing a first embodiment related to the ice-making device (also referred to as "ice slurry production device") and freezing system in the first disclosure mode;
FIG. 2 is a plan view schematically showing the first embodiment related to a refrigerant tube in a disc part, and FIG. 2B is a plan view schematically showing a second embodiment related to the refrigerant tube in the disc part;
FIG. 3 is a side elevational view schematically showing flow of an aqueous solution around the disc part;
FIG. 4A is a side elevational view schematically showing principles of a buff of the first embodiment related to a sweeping part to separate ice from the disc part, and FIG. 4B is a side elevational view schematically showing principles of a metal plate of the second embodiment related to the sweeping part to separate ice from the disc part;
FIG. 5A is a plan view schematically showing the second embodiment related to a freezing tank, and FIG. 5B is a side elevational view schematically showing the freezing tank related to FIG. 5A;
FIG. 6A is a plan view schematically showing the third embodiment related to the freezing tank, and FIG. 6B is a side elevational view schematically showing the freezing tank related to FIG. 6A;
FIG. 7A is a plan view schematically showing the fourth embodiment related to the freezing tank, and FIG. 7B is a side elevational view schematically showing the freezing tank related to FIG. 7A;
FIG. 8 is a side elevational view schematically showing a freezing system related to another embodiment;
FIG. 9 is a plan view schematically showing the freezing system related to the embodiment in FIG. 8;
FIG. 10 is an enlarged view schematically showing an ice slurry production device related to the freezing system shown in FIGS. 8 and 9;
FIG. 11 is an illustration diagram schematically showing a freezing system related to still another embodiment;
FIG. 12 is an enlarged view schematically showing a modified example of the ice slurry production device shown in FIGS. 9 and 10;
FIG. 13 is side elevational view showing a modified example of the freezing system shown in FIGS. 8 and 9;
FIG. 14 is a plan view schematically showing the freezing system related to the embodiment in FIG. 13;
FIG. 15A is an enlarged view showing a modified example of the ice slurry production device related to the freezing system shown in FIG. 11, and FIG. 15B is an enlarged view of another modified example of the ice slurry production device related to the freezing system, also shown in FIG. 11;
FIG. 16 is an enlarged view showing still another modified example of the ice slurry production device related to the freezing system, also shown in FIG. 11;
FIG. 17 is a plan view showing a modified example of a hatch portion or the ice slurry production device shown in FIG. 10;
FIG. 18 is a side elevational view showing a modified example of the ice slurry production device shown in FIG. 11;
FIG. 19A is a side elevational view partially simplifying and showing the flake ice production device related to the first embodiment of the second disclosure mode, FIG. 19B is an elevational view also partially simplifying and showing the flake ice production device, FIG. 19C is a plan view also partially simplifying and showing the flake ice production device, and FIG. 19D is a cross-sectional view schematically showing an interior of a casing along the B-B line in FIG. 19C;
FIG. 20 is a diagram for illustrating a sprinkler nozzle part;
FIG. 21 is a cross-sectional view schematically showing the flake ice production device along the A-A line in FIG. 1C;
FIG. 22 is an illustration diagram schematizing and showing an ice maker;
FIG. 23 is an illustration diagram schematizing and showing an asperity portion;
FIG. 24 is an illustration diagram cutting through a modified example related to a folded portion of the refrigerant flow path and schematically showing thereof;
FIG. 25 is an illustration diagram schematically showing the modified example of the folded portion of the refrigerant flow path also, which is obliquely viewed;
FIG. 26 is an illustration diagram showing a modified example related to a metal plate;
FIG. 27 is an illustration diagram cutting through a refrigerant flow path related to the metal plate in FIG. 8 and schematically showing thereof;
FIG. 28 is an illustration diagram schematically showing a layout of furrow portions related to FIG. 9;
FIG. 29 is a perspective view showing a drum of a drum-type flake ice production device with partial fracture;
FIG. 30 is a perspective view showing a flow path wall provided to the drum in FIG. 10;
FIG. 31 is an illustration diagram enlarging part of the flow path wall and schematically showing an asperity portion;
FIG. 32 is a perspective view schematically showing an ice-making device (also referred to as "ice slurry production device") related to a first embodiment of the third disclosure mode;
FIG. 33 is a diagram for illustrating supply of the first refrigerant and the second refrigerant;
FIG. 34A is a plan view schematically showing the first embodiment related to a refrigerant tube in a disc part, and FIG. 34B is a plan view schematically showing the second embodiment related to the refrigerant tube in the disc part;
FIG. 35 is an illustration diagram distinguishing the first refrigerant path and the second refrigerant path in the disc part by symbols and showing thereof;
FIG. 36 is a side elevational view schematically showing flow of an aqueous solution around the disc part;
FIG. 37A is a side elevational view schematically showing principles of a buff of the first embodiment related to a sweeping part to separate ice from the disc part, and FIG. 37B is a side elevational view schematically showing principles of a metal plate of the second embodiment related to the sweeping part to separate ice from the disc part;
FIG. 38 is a perspective view transparently showing an ice-making device related to an embodiment of the fourth disclosure mode;
FIG. 39 is a perspective view transparently showing the ice-making device related to the embodiment from another angle;
FIG. 40 is an illustration diagram schematically showing an ice-making system related to the embodiment;
FIG. 41 is an illustration diagram schematically showing an ice-making unit;
FIG. 42 is an illustration diagram schematically showing a disc part;
FIG. 43A is an illustration diagram showing an example of a scraping tooth contacting a disc part 4014, and FIG. 43B is an illustration diagram showing an example of existence of a clearance between a scraping tooth 4048 disc and the disc part 4014;
FIG. 44 is an illustration diagram showing an image that captured ice slurry taken from the ice-making device;
FIG. 45A is a side elevational view schematically showing an ice-making tank provided with a stirring device, and FIG. 45B is a plan view also schematically showing the ice-making tank provided with the stirring device;
FIG. 46 is an illustration diagram showing an image of a state where ice adheres to the sweeping part;
FIG. 47 is an illustration diagram schematically showing a modified example of the disc part; and
FIG. 48 is an illustration diagram schematically showing a method of manufacturing the disc part.

Description of Embodiments

This section describes plural disclosure modes. Each disclosure mode is described using plural embodiments and modified examples. Each disclosure mode solves the common challenge of providing better ice-making device and ice-making method than before.

Hereinafter, an ice-making device (also referred to as "ice slurry production device") and a freezing system of the first disclosure mode, which uses the ice slurry production device, will be described based on the drawings. FIG. 1 shows a first embodiment related to the ice slurry production device and freezing system in the first disclosure mode. A freezing system 10 shown in FIG. 1 is configured by combining an ice slurry production device 11, a freezing tank 12, an aqueous solution pump 13, etc.
Of these, the ice slurry production device 11 can make ice in the shape of flakes (also referred to as flake-shaped, fragment-shaped, small-lump-shaped, granular-shaped, etc.) (flake ice) by precipitating ice from an aqueous solution such of salt (salt water serving as brine), for example. The ice slurry production device 11 includes a freezing machine 14, a flake ice making part 15 as an ice production unit, a refrigerant guide part 16, etc. In addition, in the ice slurry production device 11, the freezing machine 14, the flake ice making part 15, and a refrigerant guide part 16 are mounted on a frame part 17, which serves as a holding unit, and are integrated with one another.
The freezing machine 14, the flake ice making part 15, and the refrigerant guide part 16 of the ice slurry production device 11 constitute a freezing cycle capable of circulating a predetermined refrigerant fluid (liquid refrigerant), to thereby compress, condense, expand, and evaporate the refrigerant. Here, as a form of freezing cycle, it is possible to adopt a variety of common ones.
The refrigerant is sent from the freezing machine 14 to the flake ice making part 15 via the refrigerant guide part 16. The refrigerant guide part 16 includes a refrigerant induction tube 18a, which introduces the refrigerant from the freezing machine 14 to the flake ice making part 15, and a refrigerant derivation tube 18b, which returns the refrigerant derived from the flake ice making part 15 to the freezing machine 14.
For the refrigerant induction tube 18a or the refrigerant derivation tube 18b, for example, a general refrigerant tube with a copper tube covered with a heat insulating material can be adopted. It is also possible to connect such refrigerant tubes via general tube couplings for the refrigerant induction tube 18a or the refrigerant derivation tube 18b.
In this embodiment, each end portion of the refrigerant induction tube 18a and the refrigerant derivation tube 18b is connected to the freezing machine 14 and the flake ice making part 15 via tube couplings, although detailed illustrations are omitted. In addition, the refrigerant induction tube 18a and the refrigerant derivation tube 18b have a curved shape so that they are bent in an inverted U-shape that protrudes upward. Furthermore, the refrigerant induction tube 18a and the refrigerant derivation tube 18b are similar in length and size to each other.
In addition, the inner portions of the refrigerant induction tube 18a and the refrigerant derivation tube 18b serve as freezing tank crossing parts 19, which are bent in an inverted U-shape. If the ice slurry production device 11 is installed so that the freezing machine 14 is located outside a freezing tank 12 (to be described later) and the flake ice making part 15 is located inside the freezing tank 12, then part of a wall part 12a of the freezing tank 12 enters the freezing tank crossing parts 19 of the refrigerant induction tube 18a and the refrigerant derivation tube 18b.
For example, it is possible to adopt flexible tubes that allow operators who assemble the ice slurry production device 11 to bend directly by hand without using tools as the refrigerant induction tube 18a and the refrigerant derivation tube 18b. And in this case, also, it is desirable to cover the perimeter of the flexible tube with a heat insulating material.
Subsequently, the flake ice making part 15 includes a cooling part 21, a rotational driving part 22 as a driving unit, a sweeping part 23 as an ice separation unit, etc. Of these, the cooling part 21 includes a disc part 26 as an ice-making plate and refrigerant tube 28.
The disc part 26 is formed of a metal plate having a rectangular (here square) plate surface (ice-making surface) and a predetermined thickness, and is fixed to the frame part 17 (to be described later). Here, the disc part 26 is not limited to the rectangular shape, but may have a circular shape. Examples of a material of the disc part 26 include copper, stainless steel, as well as steel, aluminum, and duralumin with surface treatment for anti-rust effect.
The size (dimensions) of the disc part 26 can be about 30 cm square, for example. In addition, in the embodiment, the upper surface (plate surface 26a) and the lower surface (plate surface 26b) of the disc part 26 are machined to be almost flat and parallel to each other. Furthermore, inside the disc part 26, several holes are formed in parallel at approximately equal intervals to pass through.
The refrigerant tube 28 described above passes through the holes inside the disc part 26. The refrigerant tube 28 is formed in a serpentine pattern, alternating straight and curved portions, as shown in FIG. 2A. In addition, one end portion of the refrigerant tube 28 is connected to the refrigerant induction tube 18a and the other end portion is connected to the refrigerant derivation tube 18b. Then, the refrigerant supplied by the freezing machine 14 flows inside the refrigerant tube 28 (pipeline).
In addition, the outer peripheral surface of the refrigerant tube 28 is in contact with the inner peripheral surface of the hole in the disc part 26 to enable heat transfer. As a material for the refrigerant tube 28, a copper tube generally with high thermal conductivity can be used as an example. Then, as the refrigerant flows inside the refrigerant tube 28, the heat of the disc part 26 is taken away and the disc part 26 is cooled.
Note that it is also possible to use materials other than copper (for example, stainless steel, aluminum, duralumin, etc.) for the refrigerant tube 28. It is also possible to form a coating with excellent thermal conductivity on the outer peripheral surface of the refrigerant tube 28 (or the inner peripheral surface of the hole in the disc part 26).
In addition, formation of the refrigerant tube 28 is not limited to the formation of tubes as a physical tubular component inserted into the hole of the disc part 26. For example, it is possible to omit the tubular components and use drilled holes provided inside the disc part 26 directly as the refrigerant tube (refrigerant flow path). In such a case, the refrigerant flows in contact with the inner peripheral surface of the hole in the disc part 26. In addition, if the tubular components are omitted as described above, it is possible to form a serpentine-shaped refrigerant flow path by connecting a U-shaped tube, which is folded back, to the disc part 26, and by liquid-tight connecting the internal space of the U-shaped tube with the internal space at the hole of the disc part 26.
In addition to these, it is also possible to provide serpentine pattern holes with straight and folded portions inside the disc part 26. In this case, it is considered that a cast core for forming the refrigerant flow path is used to cast to form the disc part 26 with serpentine pattern holes.
In addition, in the embodiment, the end portions 28a and 28b of the refrigerant tube 28 connected to the refrigerant induction tube 18a and the refrigerant derivation tube 18b extend in a direction perpendicular to the other straight portions in the case where the disc part 26 is viewed flat as shown in FIG. 2A. Furthermore, the end portion 28b of the refrigerant tube 28, which is connected to the refrigerant derivation tube 18b, has a positional relationship overlapping the other portions in the thickness direction of the disc part 26.
Note that, although the illustration is omitted, it is possible to form the refrigerant tube 28 in more repeated serpentine patterns to overlap, for example, double, triple, or more in the thickness direction of the disc part 26. In this way, the flow rate of the refrigerant flowing inside the disc part 26 can be increased, and thereby more effective cooling of the disc part 26 can be performed.
In addition, not limited to those described above, for example, the end portions 28a and 28b of the refrigerant tube 28 connected to the refrigerant induction tube 18a and the refrigerant derivation tube 18b may be formed to extend in a direction parallel to the other straight portions in the case where the disc part 26 is viewed flat as shown in FIG. 2B. In this way, it is possible to easily process the refrigerant tube 28 and the holes in the disc part 26. Furthermore, it becomes easy to make the disc part 26 thinner.
Subsequently, the sweeping part 23 described above includes buff support bodies 31, as shown in FIG. 3, and each buff support body 31 has plural buffs 33 attached thereto. The buffs 33 are located to face each of the plate surfaces 26a and 26b of the disc part 26 in the cooling part 21. Furthermore, in the embodiment, the buffs 33 are disposed to contact each of the plate surfaces 26a and 26b of the disc part 26 at a moderately weak pressure (low surface pressure). As will be described later, the buff 33 has a function of sweeping the ice rose out of each of the plate surfaces 26a and 26b of the disc part 26 and separating the ice from the disc part 26 (sweeping function).
Various materials and stuffs generally used for polishing can be adopted for the buff 33. For example, as a material for the buff 33, urethane, other synthetic resins, metals, wool, or the like can be adopted. In addition, examples of the stuffs for the buff 33 include sponges, foam, brushes, scrubbing brushes, resin net, non-woven fabric using various kinds of materials described above. Furthermore, the material for the buff 33 can be those with a certain degree of flexibility.
In addition, each buff 33 is attached to a rod-shaped spoke 34 provided to the buff support body 31. The four spokes 34 of the buff support body 31 are arranged at 90 degree intervals to face each of the plate surfaces 26a and 26b of the disc part 26. Furthermore, the buff support body 31 is integrally coupled to a round rod-shaped rotating transmission shaft 35.
The rotating transmission shaft 35 penetrates the disc part 26 in the thickness direction, avoiding the refrigerant tube 28, to be able to rotate in the forward and reverse direction around the shaft center. The rotation transmission shaft 35 is capable of rotational displacement with the buffs 33 with respect to the disc part 26 that remains stationary.
In the embodiment, as shown in FIG. 1, each buff 33 has a feather shape (elliptical shape), and the buffs 33 are arranged in the shape of a propeller with four blades to face each of the plate surfaces 26a and 26b of the disc part 26.
Such a sweeping part 23 is coupled to the rotational driving part 22 via the rotating transmission shaft 35. The rotational driving part 22 incorporates a motor (buff driving motor), and the rotational driving part 22 is capable of continuously rotating the sweeping part 23 in the aqueous solution Ws (the liquid level is virtually indicated by a chain double-dashed line in FIG. 1) stored in the freezing tank 12, as will be described later.
Here, the rotational driving part 22 can be a motor and a deceleration part (gear part) in one piece (geared motor). In addition, the rotational driving part 22 is located above the liquid level of the aqueous solution Ws and is positioned to be out of the aqueous solution Ws. Furthermore, the rotational driving part 22 is not limited to the one that rotates the sweeping part 23 in one direction, but may be the one that rotatively reciprocates the sweeping part 23 (the one that performs reciprocating rotation of the sweeping part 23 in the forward and reverse direction).
Note that, as for the arrangement of the buffs 33 described above, it is possible to adopt various modes, not limited to those shown in FIGS. 1 and 3. For example, the number of buffs 33 may be less than four or five or more for each of the plate surfaces 26a and 26b of the disc portion 26.
Subsequently, the frame part 17 described above is configured by, for example, joining rod-shaped components together to form a framework. As materials for the frame part 17, general angle bars, round pipes, square pipes, or extruded materials can be adopted. In FIG. 1, the components of the frame part 17 are drawn in a band plate shape to avoid a complicated drawing; however, it is desirable to select the materials taking into account the required strength and structure.
For joining the components of the frame part 17, welding, screwing (including bolt tightening), etc. can be adopted. In addition, metal or synthetic resin can be adopted as the material for the frame part 17, and of these, as the metal, a variety of common ones such as steel, stainless steel, aluminum, etc. can be adopted. Furthermore, when adopting metals such as steel, various types of general surface treatments may be performed in consideration of rust prevention.
In the frame part 17, the freezing machine 14 and the flake ice making part 15 are fixed, and the frame part 17 supports the freezing machine 14 and the flake ice making part 15. Fixing of the freezing machine 14 and the flake ice making part 15 to the frame part 17 can be carried out by common means, for example, bolt tightening or screwing. In addition, the frame part 17 supports the flake ice making part 15 so that the rotational driving part 22 of the flake ice making part 15 is out of the aqueous solution Ws.
As described above, the refrigerant induction tube 18a and the refrigerant derivation tube 18b of the refrigerant guide part 16 are connected to the freezing machine 14 and the flake ice making part 15, and the frame part 17 also supports the refrigerant induction tube 18a and the refrigerant derivation tube 18b of the refrigerant guide part 16 via the freezing machine 14 and the flake ice making part 15.
Note that, in the example shown in FIG. 1, the refrigerant induction tube 18a and the refrigerant derivation tube 18b of the refrigerant guide part 16 are supported floating against the frame part 17; however, it is also possible to form the portions (restraint portions) in the frame part 17 that supports the refrigerant induction tube 18a and the refrigerant derivation tube 18b by contacting the refrigerant induction tube 18a and the refrigerant derivation tube 18b.
In the case where the ice slurry production device 11 is placed on the floor, the freezing machine 14 is installed on the floor, sandwiching a portion of the frame part 17 located below. In contrast thereto, the flake ice making part 15 is supported at a position shifted from the freezing machine 14 with a predetermined amount in the horizontal direction and slightly higher than the lower end of the freezing machine 14.
Then, between the freezing machine 14 and the flake ice making part 15, the freezing tank crossing parts 19 of the refrigerant induction tube 18a and the refrigerant derivation tube 18B are positioned to open downwardly. Here, in FIG. 1, part of the frame part 17 and the freezing tank 12 is virtually cut out as indicated by the chain double-dashed line.
Note that it is possible to set the height from the lower end to the upper end of the ice slurry production device 11 to about 80 cm to 90 cm. In addition, the lower end of the ice slurry production device 11 can be set as the portion of the frame part 17 that is in contact with the floor, and the upper end of the ice slurry production device 11 can be set as the upper end of the rotational driving part 22. By setting the height dimension of the ice slurry production device 11 to about 80 cm, the height of the freezing tank 12, which will be described later, can allow operators performing freezing to work with ease.
Next, the freezing tank 12 and the aqueous solution Ws stored in the freezing tank 12 will be described. In the embodiment, the freezing tank 12 is formed in a rectangular container shape, and upper part is opened. In addition, although it is omitted in FIG. 1, the circumference of the freezing tank 12 is enclosed by heat insulating material. Here, as heat insulating material, it is possible to adopt a variety of common ones.
In addition, each wall (including the bottom wall) of the freezer tank 12 can be, for example, one with built-in heat insulating material or a hollow one. In the case where only each wall of the freezing tank 12 can obtain sufficient heat insulation properties, the heat insulating material around the freezing tank 12 can be omitted appropriately.
The aqueous solution Ws, which is indicated by the chain double-dashed line in FIG. 1, is an undiluted solution of the ice slurry (also referred to as brine). In the embodiment, a saline solution of a predetermined concentration (23.5% here) is used as the aqueous solution Ws. The amount of aqueous solution Ws can be set to about 200 L (liters), for example.
Many portions of the flake ice making part 15 of the ice slurry production device 11 are located inside the freezer tank 12. In other words, the freezing machine 14 of the ice slurry production device 11 is located outside the freezing tank 12 and faces the wall part 12a of one end portion in the longitudinal direction of the freezing tank 12 from the outside.
In contrast thereto, the flake ice making part 15 is located inside the wall part 12a. A predetermined amount of aqueous solution Ws is stored in the freezing tank 12. The portion from the lowermost portion to the middle height of the flake ice making part 15 is immersed in the aqueous solution Ws in the freezing tank 12. The disc part 26 is located at the lowermost portion of the flake ice making part 15, and, when the flake ice making part 15 is immersed in the aqueous solution Ws, the entire disc part 26 is also immersed in the aqueous solution Ws.
Subsequently, the function of the aforementioned aqueous solution pump 13 will be described. The aqueous solution pump 13 pumps the aqueous solution Ws, as indicated by the arrow A1 of the chain double-dashed line in FIG. 1, and the aqueous solution Ws is led to the freezing tank 12, as indicated by the arrow A2. The aqueous solution pump 13 then squirts the aqueous solution Ws toward the disc part 26 of the flake ice making part 15. Here, in FIG. 1, arrows A1 and A2 indicate the route of the aqueous solution, and the illustration of tubes is omitted.
Although it is possible to adopt various types of general pumps as the aqueous solution pump 13, it can be considered to select the aqueous solution pump 13 taking into account that solids (here, flake ice) are mixed with the aqueous solution Ws. In addition, the effect of preventing clogging of the flow path can be obtained by passing the aqueous solution Ws mixed with the flake ice through the tubes or the aqueous solution pump 13. However, in the case where the flake ice is prevented from passing through the aqueous solution pump 13, it can be considered to place a filter to remove the flake ice and foreign matters from the aqueous solution Ws at the inlet of the tube or in the front of the aqueous solution pump 13.
The aqueous solution Ws sent from the aqueous solution pump 13 is squirted from the nozzle part 41 as shown in FIG. 3. The nozzle part 41 is immersed in the aqueous solution Ws stored in the freezing tank 12, and the aqueous solution Ws (indicated by the arrow A3 here) squirted from the nozzle part 41 involves the aqueous solution Ws in the freezing tank 12 in the formation of a water flow. The aqueous solution Ws (arrow A3) squirted from the nozzle part 41 generates a flow velocity and gives momentum to the aqueous solution Ws stored in the freezing tank 12. In other words, the aqueous solution pump 13, the nozzle part 41, etc. constitute a water flow generation mechanism (propulsion mechanism) as a flow forming unit that forms the flow of the aqueous solution Ws.
As the nozzle part 41, it is possible to adopt a variety of common ones. Then, as for the nozzle part 41, examples can show the one squirting the aqueous solution Ws in a cone shape as indicated by the arrow A3, or the one squirting the aqueous solution Ws linearly, although the illustration is omitted.
The nozzle part 41 is immersed in the aqueous solution Ws to be able to generate water flow around the disc part 26 in the flake ice making part 15. The water flow generated by the aqueous solution discharged from the nozzle part 41 circulates between the wall parts 12a and 12b located at the end portions in the length direction (longitudinal direction, left and right direction in FIG. 1) of the freezing tank 12.
As described above, the disc part 26 is cooled by the cold energy of the refrigerant from the freezing machine 14; therefore, the aqueous solution Ws flowing around the disc part 26 is cooled by the disc part 26. Then, by sufficiently cooling the disc part 26, the conditions are adjusted, ice precipitates on each of the plate surfaces 26a and 26b, etc. of the disc part 26, and microscopic ice adheres to the periphery of the disc part 26.
As shown by the arrow A4 in FIG. 3, the buffs 33 of the sweeping part 23 rotate continuously and collide with the adhered ice, to sweep the surfaced and adhered ice away from the disc part 26 to be separated. Since the sweeping part 23 is rotating, the buffs 33 intermittently pass through certain locations, and thereby the ice is separated from the disc part 26 before growing large.
The ice separated from each of the plate surfaces 26a and 26b of the disc part 26 becomes flake ice, and the flake ice is caught and dispersed in the flow of the aqueous solution Ws (indicated by the arrow A5), and the aqueous solution Ws is cooled to the solidifying point of the aqueous solution Ws (about -21°C in the case of the aforementioned 23.5% saline solution).
By continuing the above-described ice adhering and sweeping of ice while giving fluidity to the aqueous solution Ws, the amount of flake ice in the aqueous solution Ws gradually increases, and ice slurry with an ice concentration (IPF) of about 10% to 30% is produced at a temperature suitable for freezing the items to be frozen (for example, about - 21°C).
The ice slurry with the aforementioned concentration of 23.5% salt water can effectively perform freezing because the solidifying point temperature (about -21°C) thereof is maintained as long as the ice remains. In addition, freezing of items to be frozen can be carried out by, for example, placing the items to be frozen in a metal basket indicated by the reference sign 45 in FIG. 1 and immersing the items in the ice slurry by an operator holding the basket 45.
Note that it is also possible to integrally assemble and fix the water flow generation mechanism such as the aqueous solution pump 13 and the nozzle part 41 to the frame part 17. In this case, the water flow generation mechanism can be integrated into the ice slurry production device 11. In addition, for example, the aqueous solution pump 13 may be installed away from the frame part 17, and only the nozzle part 41 and the tube connected to the nozzle part 41 may be fixed to the frame part 17. In the case where the aqueous solution pump 13 is installed away from the frame part 17, the weight of the frame part 17 including each equipment that the frame part 17 supports can be reduced.
Next, FIG. 4A schematically shows the buff 33 separating the ice from the disc part 26. The buff 33 attached to the spoke 34 moves horizontally (rotationally) from left to right in the figure, as indicated by the arrow C of the chain double-dashed line. In the example in FIG. 4A, the buff 33 is in contact with the plate surface 26a on the upper side of the disc part 26 at a moderately weak pressure (low surface pressure). The buff 33 is made of a material with a certain degree of flexibility and has a rectangular (in this case, almost square) cross-sectional shape.
In addition, in the example shown in FIG. 4A, the buff 33 moves while contacting the plate surface 26a of the disc part 26, to thereby cause friction; therefore, the cross-sectional shape thereof is deformed to be a parallelogram shape. Then, the buff 33 beats the ice (illustration is omitted) generated on the plate surface 26a of the disc part 26 to exert an external force to the ice and sweep the ice away from the plate surface 26a of the disc part 26. Furthermore, on the surface of the opposite side of the disc part 26 (lower plate surface 26b), the buff 33 sweeps the ice away by the same principle.
In the example shown in FIG. 4A, the cross-sectional shape of the buff 33 and the cross-sectional shape of the spoke 34 are both rectangular when the principle of sweeping by the buff 33 is explained. But not limited to this, for example, as the spoke 34, it is possible to adopt round bars and other shapes than the square bars. The cross-sectional shape of the buff 33 can also be a shape other than a rectangle, and examples of the shape other than the rectangle include a triangle, a polygon, a round, and an ellipse.
Furthermore, it is possible to adopt, not only for the cross-sectional shape of each buff but also for the planar shape, various shapes other than the feather shape. Although the illustration is omitted, it is also possible that the planar shape of the buff 33 is, for example, a round plate shape with a diameter of about 30 cm, and the number of buffs 33 is one per one surface of the disc part 26, and the buff 33 rotates horizontally around the center. Furthermore, the outer diameter of the buff 33 can be reduced to less than about 30 cm, and one or more buffs 33 can circle while rotating.
In addition, as a further modified example, power can be transmitted from the side portion (side of the end portion) of the disc part 26 to the buff (illustration is omitted) without making a hole to pass the rotating transmission shaft 35 through the disc part 26. In this case, for example, it can be considered that links (arms) of a parallel crank mechanism move alternatively and reciprocally with the disc part 26 sandwiched by the parallel crank mechanism. By adopting such a mechanism, the sweeping part 23 can sandwich the disc part 26 with the mechanism and can operate like a car wiper to sweep away the ice.
In addition, a gap of a certain amount (for example, 1 mm or less to several mm) may be formed between the buff 33 and each of the plate surfaces 26a and 26b of the disc part 26 to sweep away the ice that has grown larger than the gap.
Here, fixing of the buff 33 to the spoke 34 can be done in various ways in general. Examples of the method of fixing include bonding, screwing, (bolt tightening), riveting, and pinching.
Note that, as shown in FIG. 4B, a metal plate 38 can be used instead of the buff 33. Furthermore, other than the metal plates 38, it is also possible to adopt a synthetic resin plate, for example. When these rigid bodies are used, as shown in FIG. 4B, it is considered that a gap H can be interposed between the rigid body and the disc part 26. By doing this, it is possible to prevent wear of the metal plate 38 and the disc part 26.
In addition, by moving the metal plate 38, etc. with the gap H, turbulence can be generated, for example, in the vicinity of the metal plate 38, etc., as indicted by plural arrows D in FIG. 4B. Furthermore, although the illustration is omitted, it is considered that the turbulence can also be generated in the gap H between the metal plate 38, etc. and the disc part 26. Even if the metal plate 38, etc. is not in contact with the disc part 26, the turbulence can be used to separate the ice from the disc part 26. This turbulence tends to be generated by moving the metal plate 38, etc. quickly to some extent.
Here, fixing of the metal plate 38, etc. to the spoke 34 can be done in various modes in general. Examples of the method of fixing include welding, in addition to bonding, screwing, (bolt tightening), riveting, and pinching.
Note that the buff 33 and metal plate, etc. can be maintained by, for example, replacing at regular intervals.
Next, the measures to prevent ice adhesion on the side portions of the disc part 26 will be described. In the embodiment, ice adhered to each of the plate surfaces 26a and 26b of the disc part 26 is separated from the disc part 26 by the buffs 33 of the sweeping part 23. However, for the ice adhered to portions where buffs 33 do not come into contact, such as the side portions of the disc part 26, the water flow of the aqueous solution Ws hits, but no other external force is exerted.
Therefore, in the case where the ice adhered to the disc part 26 grows large and grows into an unexpected shape or size, it is considered that the ice compresses the surrounding equipment (for example, the refrigerant tube 28, etc.), and causes excessive load on the surrounding equipment. It is also considered that the grown ice reaches the plate surfaces 26a and 26b of the disc part 26, and interferes with the buffs 33 to prevent the operation of the buffs 33.
Therefore, in consideration of these points, it is possible to partially provide ice adhesion prevention parts to the disc part 26, as indicated by the reference signs 46 in FIGS. 2A and 2B. In the examples in FIGS. 2A and 2B, the ice adhesion prevention part 46 is formed to cover the curved portions of the refrigerant tube 28 that protrude from the disc part 26.
The ice adhesion prevention part 46 can be formed of, for example, a synthetic resin with lower thermal conductivity than the metal that is the material of the disc part 26. In addition, the surface of the ice adhesion prevention part 46 can be molded into a smooth shape without sharp corners, to thereby make the ice adhesion prevention part 46 difficult for ice to adhere. Note that, in the examples in FIGS. 2A and 2B, only the contour of the ice adhesion prevention part 46 is indicated by a chain double-dashed line.
According to the freezing system 10 and the ice slurry production device 11 related to the embodiment of the first disclosure mode as described above, in the ice slurry production device 11, the freezing machine 14, the disc part 26, the rotational driving part 22, and the buffs 33 are configured in one piece; therefore, the ice slurry production unit 11 can be unitized. Consequently, when producing the ice slurry, the ice slurry production device 11 should be placed on the floor so that the flake ice making part 15 is located inside the freezing tank 12 and the freezing machine 14 is located outside the freezing tank 12, which makes the installation of the equipment necessary for making the flake ice simpler and easier than before.
In addition, since the disc part 26 of the flake ice making part 15 is directly immersed in the aqueous solution Ws in the freezing tank 12, piping for forwarding the flake ice into the freezing tank 12 is unnecessary, and the production of ice slurry can be performed by a simple mechanism. Then, since the ice slurry can be produced directly in the freezing tank 12 where the freezing work is performed, there is no need to prepare ice once, mix the ice with the undiluted solution, and prepare ice slurry, as in the past.
Here, the actuation of the freezing system 10 will be described. At first, if the temperature of the aqueous solution Ws (for example, 23.5 percent saline solution) prepared in the freezing tank 12 is set to 15 degrees, the flake ice produced first in the disc part 26 melts immediately and cool the aqueous solution Ws when the ice slurry production device 11 is actuated. Because of this, the temperature of the aqueous solution Ws initially decreases. When the temperature of the aqueous solution Ws decreases to -21°C, which is the solidifying point of the aqueous solution Ws, the flake ice produced at the disc part 26 does not melt and is mixed with the aqueous solution Ws to form slurry. The proportion of ice in the slurry (ice concentration) can be gradually increased from zero to 10% to 30%, which is appropriate for freezing, by the actuation of the ice slurry production device 11. After the freezing work for items to be frozen is started, the ice concentration of the slurry can be maintained constant by setting the amount of flake ice produced in accordance with the amount of cold energy required for freezing the items to be frozen (for example, by adjusting the output of the freezing machine).
In addition, according to the freezing system 10 and the ice slurry production device 11 in the embodiment, it is possible to produce as much ice slurry as needed when it is needed. For this reason, there is no need for equipment to store the ice slurry in advance and send it to the freezing tank 12 when necessary, and it is easy to reduce the overall size and weight of the freezing system 10 and the ice slurry production device 11.
In addition, since the ice slurry production device 11 has a structure that couples the freezing machine 14 and the flake ice making part 15 via the frame part 17, it is possible to move the freezing machine 14 and the flake ice making part 15 together by lifting the frame part 17 by hand. Therefore, for example, after freezing, the operator can lift up the ice slurry production device 11, can move the flake ice making part 15 out of the freezing tank 12, can clean the portions immersed in the aqueous solution Ws of the flake ice making part 15 with tap water, and can maintain the portions.
In addition, it is possible to move and clean the ice slurry production device 11 without touching the refrigerant induction tube 18a or the refrigerant derivation tube 18b connecting the freezing machine 14 and the flake ice making part 15. Therefore, the possibility of deforming or breaking the refrigerant induction tube 18a and the refrigerant derivation tube 18b when the ice slurry production device 11 is moved or cleaned can be reduced.
Furthermore, the ice slurry production device 11 can be installed by changing the orientation thereof, not limited to the orientation shown in FIG. 1. For example, without moving the freezing tank 12 shown in FIG. 1, the ice slurry production device 11 can be replaced around the freezing tank 12 at the center by changing the orientation to either 90 degrees, 180 degrees, or 270 degrees. In addition, in this case, it is also possible to move the nozzle part 41. However, if sufficient water flow can be generated in the aqueous solution Ws, it is possible to change the orientation of the ice slurry production device 11 without changing the position of the nozzle part 41.
Here, if the nozzle part 41 and the aqueous solution pump 13, etc. are assembled to the frame part 17, the nozzle part 41 and aqueous solution pump 13, etc. also change the orientation with the flake ice making part 15, etc. in an integrated manner.
In addition, in the freezing system 10 of the embodiment, since the ice is swept away at both plate surfaces 26a and 26b of the disc portion 26 in the ice slurry production device 11, it is easy to enlarge the area to which the ice adheres, and it is possible to produce more ice slurry in a short time. Here, it may be possible to arrange the plural disc parts 26 (for example, two) in parallel, provide the buffs facing each disc part 26, and rotate these buffs using the rotating transmission shaft 35. This makes it possible to produce more ice slurry in a shorter time.
In addition, the frame unit 17 supports the flake ice making part 15 so that the rotational driving section 22 of the flake ice making part 15 is out of the aqueous solution Ws. For this reason, it is possible to protect the rotational driving part 22 from the aqueous solution Ws even if the flake ice making part 15 is immersed in the aqueous solution Ws.
Furthermore, since the flake ice is made and the ice slurry is produced in the freezing tank 12 which is opened at the upper side, it is considered that the ice may melt more easily than, for example, a case in which the flake ice or the ice slurry is produced in a hermetically sealed environment; however, by providing sufficient heat insulation to the freezing tank 12, it is possible to prevent the ice from melting.
In addition, in the freezing system 10 of the embodiment, not alcohol (alcohol brine) but the aqueous solution Ws, which is the salt water (salt water brine), is used as the undiluted solution of the ice slurry, costs are cheap, and handling is easy as compared to a case in which alcohol is used.
Furthermore, depending on the type, the thermal conductivity of alcohol is around 0.20W/mK, which is lower than the thermal conductivity of salt water (about 0.58W/mK), and the thermal conductivity of the flake ice (approximately 2.2W/mK). In addition, alcohol brine freezing uses temperature changes caused by sensible heat, while salt water brine freezing mainly uses state changes caused by latent heat. Furthermore, the salt water brine freezing uses both ice and an aqueous solution to cool the items to be frozen, and freezes the items to be frozen by hitting (colliding) the ice against the items to be frozen.
Furthermore, by downsizing the ice slurry production device 11 as in the embodiment to make it easier to clean and maintain, the following expansion of applications can be expected. For example, it is possible to install the ice slurry production device 11 not only in environments where it is easy to secure large spaces such as factories of frozen item sellers and food markets, but also in restaurants and shops in city areas.
Here, in the ice slurry production device 11, common ones can be adopted for the freezing machine 14, the refrigerant induction tube 18a, the refrigerant derivation tube 18b, the aqueous solution pump 13, the nozzle part 41, the frame part17, etc. In addition, since the ice slurry production device 11 is easy to miniaturize, it is possible to select and adopt small and inexpensive equipment for the above-described freezing machine 14, etc. Therefore, it is possible to manufacture the ice slurry production device 11 at a lower cost and cheaper than conventional large-scale one. As a result, the freezing system 10 and the ice slurry production device 11 can be easily popularized to restaurants in terms of price.
Note that, in the freezing system 10 shown in FIG. 1, the aqueous solution pump 13 and the nozzle part 41 constitute the water flow generation mechanism that generates water flow in the freezing tank 12 as described above. In addition, as modified example, the aqueous solution pump 13 and the nozzle 41 integrally assembled and fixed to the frame part 17 were described above.
However, instead of the aqueous solution pump 13 and the nozzle part 41, or in combination with the aqueous solution pump 13 and the nozzle part 41, it is possible to provide a water flow generation mechanism in the freezing tank 12. Hereinafter, an embodiment providing the water flow generation mechanism to the freezing tank 12 will be described. Note that, those similar to the freezing system 10 shown in FIG. 1 are assigned with the same reference signs, and detailed descriptions thereof will be appropriately omitted.
FIGS. 5A and 5B schematically show a freezing tank (hereafter, assigned with a reference sign 52) with a water flow generation mechanism. FIG. 5A schematically shows the freezing tank 52 from above, and FIG. 5B cuts through the freezing tank 52 and schematically shows thereof from the lateral side.
As indicated by the arrow B in FIG. 5A, water flow circulating counterclockwise in the figure is generated in the freezing tank 52. The water flow is formed using screw part 43 located at each of wall parts 52a and 52b positioned at end portions in the longitudinal direction of the freezing tank 52. As shown in FIG. 5A, the screw parts 43 are located opposite to each other at positions deviated (shifted) in the horizontal direction (in this case, the depth direction of the freezing tank 52). In addition, as shown in FIG. 5B, the screw parts 43 are located approximately at the same height as each other.
Then, rotation of the screw parts 43 in the aqueous solution Ws generates the water flow in the reverse direction, which circulates between the wall parts 52a and 52b located at the end portions in the longitudinal direction of the freezing tank 52. In addition, since the planar shape of the freezing tank 52 is rectangular, the aqueous solution WS circulates almost like a racetrack (also referred to as an oval shape) when viewed flat as shown in FIG. 5A.
Here, FIGS. 5A and 5B show three items to be frozen with the reference sign 48, which are immersed in the aqueous solution Ws. As for the items to be frozen, various kinds of foods requiring rapid freezing can be shown as examples. Here, the item to be frozen 48 is also shown schematically by a rectangular figure. In addition, it is also possible to place the three items to be frozen 48 in a single basket (in this case, a metal wire basket) 45, etc., as shown in FIG. 1, and immerse the basket 45 in the aqueous solution Ws, for example, by an operator holding thereof by hand.
In the example of FIGS. 5A and 5B, the disc part 26 (combined with the sweeping part 23) is located in one corner of the freezing tank 52 (upper right corner in FIG. 5A), as shown in FIG. 5A. In addition, the items to be frozen 48 are immersed in the freezing tank 52 to be arranged in line in the length direction of the freezing tank 52 (the longitudinal direction corresponding to the left and right direction in FIG. 5A). Furthermore, one of the items to be frozen 48 faces the disc part 26 in the width direction (the short direction corresponding to the vertical direction in FIG. 5A) of the freezing tank 52.
In addition, as shown in FIG. 5B, the disc part 26 and the items to be frozen 48 are positioned approximately at the same height as the screw parts 43 (in this case, the rotary shaft of the screw part 43). The circulating aqueous solution Ws flows while hitting the disc part 26 and the items to be frozen 48.
Here, in the example in FIGS. 5A and 5B, the size (length x depth x height) of the freezing tank 52 can be the same as that of the freezing tank 12 in the example shown in FIG. 1. In addition, in FIG. 5B, the disc part 26 is located behind one item to be frozen 48 located at the right end of the figure.
It is also possible to use one basket 45 (illustration is omitted) for each of the three items to be frozen 48 and to immerse the plural baskets 45 (in this case, three) in the freezing tank 52, not limited to one basket 45 for three items to be frozen 48. In this case, it is possible to replace the items to be frozen 48 in FIGS. 5A and 5B with the respective baskets 45, to thereby grasp the invention related to the embodiment.
Furthermore, in the example in FIGS. 5A and 5B, the water flow in the freezing tank 52 is a horizontal flow that circulates in the horizontal direction. In addition, as shown in FIG. 5A, a partition plate 53 is placed between the three items to be frozen 48 and the disc part 26, and the shape (planar shape) of the four corners of the freezing tank 52 is an arc where an R is formed. The water flow in the freezing tank 52 is smoothly guided by the R shape in the corner of the freezing tank 52 and the partition plate 53, and circulates horizontally in the freezing tank 52. In FIG. 5B, the illustration of the partition plate 53 is omitted.
Subsequently, FIGS. 6A and 6B schematically show a freezing tank 54 related to another embodiment. FIG. 6A schematically shows the freezing tank 54 from above, and FIG. 6B cuts through the freezing tank 54 and schematically shows thereof from the lateral side. Here, those similar to the example shown in FIGS. 5A and 5B are assigned with the same reference signs, and detailed descriptions thereof will be appropriately omitted.
In the example shown in FIGS. 6A and 6B, the screw parts 43 are located at the wall parts 54a and 54b, respectively, at the end portions in the longitudinal direction of the freezing tank 54. As shown in FIG. 6A, the disc part 26 is located at one corner (the lower left corner in FIG. 6A) of the freezing tank 54, and the items to be frozen 48 are immersed in the freezing tank 54 so that the items are located almost on the same straight line with the disc part 26.
Furthermore, as shown in FIG. 6B, the disc part 26 and the items to be frozen 48 are positioned approximately at the same height as the screw parts 43 (in this case, the rotary shaft of the screw part 43). The circulating aqueous solution Ws flows while hitting the disc part 26 and the items to be frozen 48, as indicated by the arrow B.
In addition, in the example shown in FIGS. 6A and 6B, the dimension in the width direction of the freezing tank 54 is smaller than the freezing tank 52 in the example in FIGS. 5A and 5B. In other words, since the items to be frozen 48 are arranged almost on the same straight line with the disc part 26, the depth of the freezing tank 54 is set smaller than the freezing tank 52 in the example of FIGS. 5A and 5B.
Furthermore, similar to the example shown in FIGS. 5A and 5B, the water flow in the freezing tank 54 is a horizontal flow that circulates in the horizontal direction in the example in FIGS. 6A and 6B. In addition, as shown in FIG. 6A, a partition plate 55 is placed between the three items to be frozen 48 and the disc part 26, and the wall part 54c facing thereto, and the shape (planar shape) of the four corners of the freezing tank 54 is an arc where an R is formed. The water flow in the freezing tank 54 is smoothly guided by the R shape in the corner of the freezing tank 54 and the partition plate 55, and circulates horizontally in the freezing tank 54. In FIG. 6B, the illustration of the partition plate 55 is omitted.
According to the freezing system having the freezing tank 54 as shown in FIGS. 6A and 6B, it is possible to downsize the freezing tank 54 (with a thinner depth), and thereby it becomes possible to downsize the freezing system further.
Subsequently, FIGS. 7A and 7B schematically show a freezing tank 56 related to another embodiment. FIG. 7A schematically shows the freezing tank 56 from above, and FIG. 7B cuts through the freezing tank 56 and schematically shows thereof from the lateral side. Here, those similar to the example shown in FIGS. 4A and 4B are assigned with the same reference signs, and detailed descriptions thereof will be appropriately omitted.
In the example shown in FIGS. 7A and 7B, the screw parts 43 are located at the wall parts 56a and 56b, respectively, at the end portions in the longitudinal direction of the freezing tank 56. As shown in FIG. 7A, the disc part 26 is located at one corner (the lower left corner in FIG. 7A) of the freezing tank 56, and the items to be frozen 48 are immersed in the freezing tank 56 so that the items are located almost on the same straight line with the disc part 26. Furthermore, the screw parts 43 are located at the end portions in the longitudinal direction (length direction) of the freezing tank 56 and are located almost in the same straight line with each other. In addition, as shown in FIG. 7A, the screw parts 43 are located opposite to each other at positions deviated (shifted) in the height direction.
Furthermore, in the example in FIGS. 7A and 7B, the water flow in the freezing tank 56 is a lengthwise flow that circulates in the lengthwise direction. In addition, as shown in FIG. 7B, the shape (side surface shape) of the corners at the bottom portion of the freezing tank 56 is an arc where an R is formed. The water flow in the freezing tank 56 is smoothly guided by the R shape in the corner of the freezing tank 56, and circulates lengthwise in the freezing tank 56.
According to the freezing system having the freezing tank 56 as shown in FIGS. 7A and 7B, the aqueous solution Ws can be circulated in the lengthwise direction (in the height direction), and a vertical aqueous solution circulation system can be realized. Then, it becomes possible to efficiently freeze the items to be frozen 48 with a higher height.
Note that, although the illustration is omitted, a water inlet to which the aqueous solution Ws is supplied may be provided to each of the freezing tanks 12, 52, 54 and 56 described so far, and the aqueous solution Ws may be supplied to the freezing tanks 12, 52, 54 and 56 through the water inlet. In addition, it is also possible to supply tap water to each of the freezing tanks 12, 52, 54 and 56 from the water inlet, mix salt, etc. into the tap water, and create the aqueous solution Ws in each of the freezing tanks 12, 52, 54 and 56. Furthermore, it is possible to provide a faucet with a valve (flow rate control valve) to the water inlet.
FIGS. 5 to 7 show freezing tanks 52, 54, and 56 having a water flow generation mechanism, but as shown in FIG. 1, if the freezing tank 12 without the water flow generation mechanism uses the water flow generation mechanism provided with the aqueous solution pump 13 and the nozzle part 41 to provide a flow to the aqueous solution, there is no need for processing to install the water flow generation mechanism in the freezing tank, and a general-purpose heat-insulating water tank can be used as the freezing tank, which is low cost. However, in the case where the water flow generation mechanism is provided to the freezing tanks 52, 54, and 56, as shown in the examples in FIGS. 5 to 7, the aqueous solution Ws can be easily circulated. In addition, in the case where the water flow generation mechanism by the aqueous solution pump 13, etc. and the water flow generation mechanism of the freezing tanks 52, 54, and 56 are used together, it becomes easier to circulate the aqueous solution Ws even more.
Each of the embodiments described so far is an example of the suitable embodiment of the first disclosure mode; however, the present invention is not limited thereto, and is able to be modified or changed in various forms within the scope not departing from the gist of the invention. For example, for the freezing system 10, the description was given to configure thereof by combining the ice slurry production device 11, the freezing tank 12, the aqueous solution pump 13, the nozzle part 14, etc., but it is also possible to configure the "ice slurry production device" including the freezing tank12, the aqueous solution pump 13, the nozzle part 14, etc.
In addition, the freezing system and the ice slurry production device can be of the type shown in FIGS. 8 to 10, and the type shown in FIG. 11. In the following, other types of freezing systems and the ice slurry production device will be described based on FIGS. 8 to 10 and 11. Note that, for those similar to the freezing system 10 and the ice slurry production device 11 of the type shown in FIG. 1, descriptions thereof will be appropriately omitted. In addition, those similar to the freezing system 10 and the ice slurry production device 11 of the type shown in FIG. 1 are assigned with the same reference signs, and descriptions thereof will be appropriately omitted.
A freezing system 110 and an ice slurry production device 111 of the type shown in FIGS. 8 to 10 use a tank (hereinafter referred to as "ice slurry production tank") 113. The ice slurry production tank 113 is formed cylindrically as shown in FIGS. 8 and 9, and an aqueous solution (reference sign is omitted), which serves as the undiluted solution of the ice slurry (also referred to as brine), is stored inside the tank. On side surfaces of the ice slurry production tank 113, the ice slurry production device 111 and the water flow generation mechanism (propulsion mechanism) 142 as a flow forming unit are assembled to prevent the leakage of the aqueous solution.
Of these, the water flow generation mechanism 142 has a screw part 43. The screw part 43 is located inside the ice slurry production tank 113, and a rotational driving part 144 located outside the ice slurry production tank 113 rotationally drives the screw part 43 around the shaft center. Furthermore, the water flow generation mechanism 142 is obliquely disposed to the ice slurry production tank 113, and is fixed to the ice slurry production tank 113 at the angle in the vertical direction indicated by the reference sign α1 in FIG. 8 or at the angle in the horizontal direction indicated by the reference sign α2 in FIG. 9. The screw part 43 points toward the ice slurry production device 111 (to be described later), which rotates to generate a flow of the aqueous solution (water flow) in the ice slurry production tank 113.
As shown in FIGS. 9 and 10, the ice slurry production device 111 includes a cooling part 121, a rotational driving part 122, and a sweeping part 123 as an ice separation unit, etc. Of these, the cooling part 121 and the sweeping part 123 are located inside the ice slurry production tank 113. The rotational driving part 122 is located outside the ice slurry production tank 113.
The cooling part 121 includes a disc part 126 and a refrigerant tube 128. As for the disc part 126 and the refrigerant tube 128, it is possible to adopt the one similar to the cooling part 21 of the ice slurry production device 11 shown in FIG. 1. In addition, the refrigerant tube 128 is connected to the freezing machine (illustration is omitted) to allow the refrigerant supplied from the freezing machine to flow, and, as for the freezing machine, similar to the ice slurry production device 11 shown in FIG. 1, it is possible to adopt a variety of common ones.
The disc part 126 is fixed to the inside of ice slurry production tank 113 via a stay 141. The stay 141 is fixed to a hatch part 143 that is detachably attached to the ice slurry production tank 113. Then, the disc part 126 is supported by the stay 141 at the position away from the inner peripheral surface of the hatch part 143.
Here, as shown in FIGS. 8 and 10, the hatch part 143 constitutes part of the ice slurry production tank 113, and is sealed to prevent leaks of the aqueous solution and assembled to the ice slurry production tank 113. Furthermore, although the illustration is omitted, the hatch part 143 is assembled to the ice slurry production tank 113 via a locking mechanism. In addition, the refrigerant tube 128 is also sealed to prevent leaks of the aqueous solution and penetrates the hatch part 143. Furthermore, in the ice slurry production device 111, the cooling part 121, the rotational driving part 122, and the sweeping part 123 constitute an ice production unit.
As shown in FIG. 10, the rotational driving part 122 is fixed to the outer peripheral side of the hatch part 143. Furthermore, the rotational driving part 122 incorporates a motor (buff driving motor), and a rotary shaft 145 of the motor is sealed to prevent leaks of the aqueous solution and penetrates the hatch part 143. The rotational driving part 122 can continuously rotate the sweeping part 123 in the aqueous solution stored in the ice slurry production tank 113. Here, the rotational driving part 122 can be a motor and a deceleration part (gear part) in one piece (geared motor).
The sweeping part 123 includes buffs 133 fixed to the rotary shaft 145 in the rotational driving part 122. As for the materials and stuffs for the buff 133, it is possible to adopt those similar to the buff 33 of the ice slurry production device 11 shown in FIG. 1. In addition, the shape of the buff 133 can adopt those similar to the buff 33 (feather shape, etc.) of the ice slurry production device 11 shown in FIG. 1.
In the example shown in FIGS. 8 to 10, similar to the example shown in FIG. 1, in the aqueous solution, the disc part 126 is cooled by the cold energy of the refrigerant from the freezing machine (illustration is omitted), and the aqueous solution Ws flowing around the disc part 126 is cooled by the disc part 126. Then, by sufficiently cooling the disc part 126, the conditions are adjusted, ice precipitates on each of the plate surfaces 126a and 126b of the disc part 126, and microscopic ice adheres to the disc part 126.
As shown by the arrow A6 in FIG. 10, the buffs 133 of the sweeping part 123 rotate continuously and collide with the adhered ice, to sweep the ice away from the disc part 126 to be separated. Since the disc part 126 is rotating, the buffs 133 intermittently pass through certain locations, and thereby the ice is separated from the disc part 126 before growing large.
The ice separated from each of the plate surfaces 126a and 126b of the disc part 126 becomes flake ice, and the flake ice is caught and dispersed in the flow of the aqueous solution, and then mixed into the aqueous solution to form the ice slurry. By continuing the ice adhering and sweeping of ice like this while giving fluidity to the aqueous solution, the amount of flake ice in the aqueous solution gradually increases, and the ice slurry at a certain temperature (for example, about -21°C) is stored in the ice slurry production tank 113.
Furthermore, although the illustration is omitted, the ice slurry production tank 113 is connected to the freezing device, in which the items to be frozen are subjected to immersion, via an ice slurry supply tube and an ice slurry return tube; therefore, it is possible to supply and recover the ice slurry to and from the freezing device. Note that, as for the ice slurry supply tube, the ice slurry return tube, the freezing device, and equipment attached to these, it is possible to adopt those similar to the ice slurry supply tube (45), the ice slurry return tube (46), the freezing device (6), and the equipment attached thereto in the above-described Patent Document 1 ( Japanese Patent Application Laid-Open Publication No. 2019-207046 ).
According to the freezing system 110 and the ice slurry production device 111, it is possible to produce ice slurry with the small and simple ice slurry production device 111. In addition, since the ice slurry production device 111 is provided in the detachable hatch part 143, the aqueous solution is reduced to a point where the liquid level is lower than the hatch part 143, and the hatch part 143 is removed from the ice slurry production tank 113; therefore, it is possible to easily clean and maintain the ice slurry production device 111.
Note that it may be possible to arrange the plural disc parts 126 (for example, two or three) in parallel (coaxially), provide the buffs facing each disc part 126, and rotate these buffs. This makes it possible to produce more ice slurry in a shorter time. FIG. 12 shows an example in which two disc parts 126 are arranged in parallel (coaxially). In addition, in FIG. 12, the illustration of the refrigerant tubes connected to the disc parts 126 located inside (the upper stage of FIG. 12, the stage near the center of the ice slurry production tank 113) is omitted to avoid complicated illustration.
Furthermore, instead of applying the water flow with screws as shown in FIGS. 8 to 10, the cooling part 121 with disc part 126 and the buffs 133, etc. are placed on the water surface of the aqueous solution Ws, such as in the freezing system 150 shown in FIGS. 13 and 14; thereby aqueous solution Ws pumped up by the pump (aqueous solution pump) 151 may be continuously supplied from the supply tube part 152 at a sufficient flow velocity to each ice-making surface ( plate surfaces 126a and 126b) of the disc part 126. In this case, if the aqueous solution is continuously supplied at a sufficient (moderate) flow velocity to each ice-making surface ( plate surfaces 126a and 126b), it is practically the same as placing (immersing) the disc part 126 in the aqueous solution Ws. If the cooling part 121 is placed outside of the aqueous solution Ws in this way, the cooling part 121 is located on the water surface, thereby making it easier to maintain the cooling part 121. Here, the supply tube part 152 is fixed to the ice slurry production tank 113 at the angle in the vertical direction indicated by the reference sign α 3 in FIG. 13 or at the angle in the horizontal direction indicated by the reference sign α 4 in FIG. 14.
In addition, the freezing system 110 shown in FIGS. 8 and 9 was described as being configured by combining the ice slurry production device 111 and the water flow generation mechanism 142, etc., but the "ice slurry production device" can be configured to include the ice slurry production device 111 and the water flow generation mechanism 142, etc.
Next, the freezing system 160 and the ice slurry production device 161 shown in FIG. 11 will be described. Note that those similar to the freezing system 10 and the ice slurry production device 11 shown in FIG. 1, the freezing system 110 and the ice slurry production device 111 shown in FIGS. 8 to 10 are assigned with the same reference signs, and descriptions thereof will be appropriately omitted.
The ice slurry production device 161 of the freezing system 160 shown in FIG. 11 includes the cooling part 121, the rotational driving part 122, and the sweeping part 123 similar to those in the example shown in FIGS. 8 to 10. However, in the ice slurry production device 161 shown in FIG. 11, the cooling part 121 and the sweeping part 123 are contained in a case 162.
The case 162 has external dimensions somewhat larger than the sweeping part 123, and forms a space portion 163 around the sweeping part 123 for the distribution of the aqueous solution. In addition, in the case 162, an aqueous solution inlet 164 and an aqueous solution outlet 165 are formed.
The aqueous solution inlet 164 is connected to a brine tank (aqueous solution tank) 168 via an aqueous solution pump 166 and a flow rate control valve 167. The aqueous solution in the aqueous solution tank 168 is continuously supplied into the case 162 by opening the flow rate control valve 167 to actuate the aqueous solution pump 166. Here, in the example shown in FIG. 11, the aqueous solution pump 166 functions as a water flow generation mechanism (propulsion mechanism) as a flow forming unit.
The aqueous solution outlet 165 of the case 162 is connected to an ice slurry tank 173. A temperature sensor 171 and an IPF (ice concentration) sensor 172 are installed in the tube between the aqueous solution outlet 165 and the ice slurry tank 173.
In such an ice slurry production device 161, similar to the example shown in FIGS. 8 to 10, in the aqueous solution, the disc part 126 is cooled by the cold energy of the refrigerant from the freezing machine (illustration is omitted), and the aqueous solution flowing around the disc part 126 is cooled by the disc part 126. As indicated by the arrow A6 in FIG. 11, the buffs 133 of the sweeping part 123 rotate continuously and collide with the ice rose out of and adhered to the disc part 126, to thereby sweep the ice away from the disc part 126 and the ice is separated.
The ice separated from the disc part 126 becomes flake ice, and the flake ice is caught and dispersed in the flow of the aqueous solution, and then mixed into the aqueous solution to be discharged from the case 162. The aqueous solution mixed with flake ice is sequentially forwarded to the ice slurry tank 173 and stored in the ice slurry tank 173.
The temperature of the ice slurry sent from the ice slurry production device 161 is monitored using the temperature sensor 171. The temperature of the disc part 126 is then adjusted so that the temperature of the ice slurry is at a predetermined temperature (for example, about -21°C). In addition, the ice concentration in the pipeline for the ice slurry is monitored using an IPF sensor 172, and the flow rate control valve 167 is adjusted to maintain a predetermined value of the ice concentration.
Here, the above-described temperature control and ice concentration control may be performed manually by the operator while visually observing the output of the temperature sensor 171 and the IPF sensor 172, or may be performed by automatic control using the output signals of the temperature sensor 171 and the IPF sensor 172.
In addition, in the example shown in FIG. 11, a depression of the space portion 163 in the case 162 is filled with a filling material 169 so that the flow of the aqueous solution and the ice slurry is smooth without stagnation. As the filling material 169, it is possible to adopt a synthetic resin, etc. Here, in FIG. 11, the filling material 169 has hatching indicating a cross section; however, for the case 162, the illustration of hatching is omitted to avoid the complicated illustration.
According to such freezing system 160 and ice slurry production device 161, it is possible to produce ice slurry with the even more small ice slurry production device 161. In addition, by reducing the size of the case 162, the flow rate of the aqueous solution (flow rate of bypass flow) in the case can be increased.
Here, as schematically shown in FIG. 15A, the plural (for example, three) disc parts 126 are arranged in parallel (coaxially), there are provided buffs 133 facing each disc part 126, and these buffs are rotated and a partition plate 154 may be provided so that the aqueous solution flows evenly in parallel to the three disc parts 126. Here, the arrow E in FIG. 15A indicates the flow of the aqueous solution. In addition, in FIG. 15A, the partition plate 154 is drawn to have a triangular cross section, and the aqueous solution flowing from the aqueous solution inlet 164 is divided in two directions.
In addition, as schematically shown in FIG. 15B, the plural (for example, three) disc parts 126 are arranged in parallel (coaxially) in the same manner, there are provided buffs 133 facing each disc part 126, and these buffs are rotated and partition plates 156 and 157 may be provided so that the aqueous solution serially flows while sequentially contacting the three disc parts 126 arranged coaxially (so that the aqueous solution turns back in a hooked shape twice). In FIG. 15B, one partition plate 156 (in the first stage) guides the aqueous solution flowing in from the aqueous solution inlet 164, and the other partition plate 157 (in the second stage) guides the aqueous solution heading for the aqueous solution outlet 165.
In addition, as schematically shown in FIG. 16, it is also possible to allow the aqueous solution to flow while sequentially contacting the three disc parts 126 arranged in series in the direction of the flow. Arrangement of the disc parts 126 as in the examples in FIGS. 15A, 15B and 16 makes it possible to produce more ice slurry in a shorter time. In addition, arrangement of the disc parts 126 as in the examples in FIGS. 15A and 15B makes it possible to arrange the disc parts 126, etc. while suppressing the installation area (projection area) of the disc parts 126, etc. In addition, arrangement of the disc parts 126 as in the example in FIG. 16 makes it possible to simplify the route of the water flow.
Note that the temperature control and ice concentration control performed in the freezing system 160 in FIG. 11 can also be appropriately adopted in the freezing system 10 in FIG. 1 and the freezing system in FIGS. 8 to 10, 13, and 14. In addition, the corners of the case 162 in the ice slurry production device 161 in FIG. 11 can be formed into an R shape to smoothly guide the water flow. This is also true for the ice slurry production device of the types shown in FIGS. 15A, 15B, and 16.
Next, a modified example related to the freezing system 110 and the ice slurry production device 111 of the type shown in FIGS. 8 to 10 (furthermore, the freezing system 150 shown in FIGS. 13 and 14) will be described based on FIG. 17. Note that those similar to the freezing system 110 and the ice slurry production device 111 of the type shown in FIGS. 8 to 10 are assigned with the same reference signs, and descriptions thereof will be appropriately omitted.
In the example shown in FIGS. 8 to 10, etc., the disc part 126 of the cooling part 121 was located inside the hatch part 143, and the refrigerant tube 128 penetrated the hatch part 143. In contrast thereto, in the example shown in FIG. 17, a disc part 186 in an ice slurry production device 181 enters an opening portion 193a formed in a hatch part 193, and somewhat protrudes inside the hatch part 193 to block the opening portion 193a. The outer side surface 186b of the disc part 186 is exposed to the outside of the ice slurry production tank 113 through the opening portion 193a.
The area around the disc part 186 is liquid-tightly sealed to prevent leaks of the aqueous solution. For the sealing means, it is possible to adopt common ones, such as application of sealing material or welding. In the example in FIG. 17, as partially shown, a sealing material 194 blocks the area around the disc part 186. In the disc part 186, only the inner side surface 186a is in contact with the aqueous solution in the ice slurry production tank 113.
In addition, in the example in FIG. 17, a refrigerant tube 188 is derived from the outer side surface186b of the disc part 186 to the outside of the ice slurry production tank 113. Furthermore, the rotational driving part 122 is located outside the disc part 186. The rotary shaft 145 of the rotational driving part 122 is sealed to prevent leaks of the aqueous solution and penetrates the disc part 186 in the horizontal direction. The rotational driving part 122 can continuously rotate the sweeping part 123 in the aqueous solution stored in the ice slurry production tank 113.
The sweeping part 123 includes the buffs 133 inside the disc part 186. The buff 133 is fixed to the rotary shaft 145 of the rotational driving part 122, and collides with the ice adhered to the inner side surface 186a of the disc part 186, where the aqueous solution contacts, to separate the ice from the disc part 186.
By adopting a configuration as in the example shown in FIG. 17, the refrigerant tube 188 does not come into direct contact with the aqueous solution, and thereby it is possible to prevent the ice from adhering to the refrigerant tube 188.
Next, a modified example related to the freezing system 160 and the ice slurry production device 161 of the type shown in FIG. 11 will be described based on FIG. 18. Note that those similar to the freezing system 160 and the ice slurry production device 161 of the type shown in FIG. 1 are assigned with the same reference signs, and descriptions thereof will be appropriately omitted.
In the example shown in FIG. 11, the disc part 126 of the cooling part 121 was contained inside the case 162, and the refrigerant tube 128 penetrated the case 162. In contrast thereto, in the example shown in FIG. 18, end portions 207 of the disc part 206 in the ice slurry production device 201 protrude from a case 212, and a refrigerant tube 218 is derived to the outside from the end portions 207 of the disc part 196.
To the case 212, plural salt water inlet tubes (aqueous solution inlet tubes) 219a and, likewise, plural salt water outlet tubes (aqueous solution outlet tubes) 219b are connected, and the salt water is introduced into the space portion 163 in the case 212 via the salt water inlet tubes 219a. The salt water (aqueous solution) introduced in the space portion 163 in the case 212 contacts the plate surfaces 206a and 206b of the disc part 206 and is cooled by the disc part 206.
The ice rose out of and adhered to the plate surfaces 206a and 206b of the disc part 206 is swept away and separated from the disc part 206 by the rotating buffs 133. Then, the ice separated from the disc part 206 becomes flake ice, and the flake ice is mixed into the salt water to be discharged from the case 212 via the salt water outlet tubes 219b.
The rotational driving part 122, which rotates the buffs 133, is located on the top of the case 212, and the rotary shaft 145 of the rotational driving part 122 is inserted downward into the case 212. The area between the rotary shaft 145 and the case 212 is sealed to prevent leaks of the salt water.
By adopting a configuration as in the example shown in FIG. 18, the refrigerant tube 218 does not come into direct contact with the salt water, and thereby it is possible to prevent the ice from adhering to the refrigerant tube 218. In addition, in the example shown in FIG. 18, since the rotary shaft 145 of the rotational driving part 122 is inserted downward into the case 212, a hole (reference sign is omitted) of the case 212 for the rotating shaft 145 opens upward; therefore, it is unlikely that the salt water leaks from the case 212.

Hereinafter, a flake ice production device related to an embodiment of the second disclosure mode will be described based on the drawings. Note that, here, the flake ice production device is taken as an example of an ice-making device, but the second disclosure mode is not limited thereto; for example, the mode can also be applied to other types of ice-making device such as an ice slurry production device.
FIGS. 19A to 19D show the flake ice production device 2010 related to an embodiment of the second disclosure mode. FIG. 19A is a side elevational view of the flake ice production device 2010, FIG. 19B is an elevational view, FIG. 19C is a plan view, and FIG. 19D is a cross-sectional view along the B-B line in FIG. 19C. FIG. 20 shows a sprinkler nozzle part 2018 provided to the flake ice production device 2010, and FIG. 21 is a cross-sectional view along the A-A line in FIG. 19C.
FIGS. 19A to 19D, 20, and 21 were prepared using the blueprints (assembly drawings) of the flake ice production device 2010 and the sprinkler nozzle part 2018. In these diagrams, configurations and lines are omitted as appropriate, and hidden lines (broken lines), virtual lines (chain double-dashed lines), and a centerline (long-dot-and-dash line), etc. are used to the extent there is no hindrance to grasp an overview of the configuration.
As shown in FIGS. 19A to 19D, 20, and 21, the flake ice production device 2010 includes a rectangular parallelepiped casing 2012, a geared motor (hereinafter referred to as the "motor") 2014, a drive shaft 2016 (shown in FIG. 19D), two sets of sprinkler nozzle parts 2018, a metal plate (metal body) 2020 and two sets of scraping tooth 2022 (shown in FIG. 21), etc.
Of these, the motor 2014 is located outside the casing 2012, and the motor 2014 incorporates a driving force transmission gear (illustration is omitted). The drive shaft 2016 is coupled to the motor 2014, and the drive shaft 2016 is inserted almost horizontally into the casing 2012.
As shown in FIG. 19C, there are two sets of sprinkler nozzle parts 2018, and each sprinkler nozzle part 2018 has a main tube 2024 that penetrates the casing 2012 in the horizontal direction. As shown in FIG. 20, each sprinkler nozzle part 2018 includes two sets of a short tube 2026 and a long tube 2028 extending directly downward from the main tube 2024.
To each sprinkler nozzle part 2018, an aqueous solution containing a solute (also referred to as brine, to be described later) is supplied as indicated by the arrow A1 in FIGS. 19B and 19C. The tip end portions of the short tube 2026 and the long tube 2028 are provided with the tip end nozzle parts 2030 and 2032. Then, the brine is sprayed from the tip end nozzle parts 2030 and 2032 to each plate surface of the metal plate 2020 disposed in a standing position inside the casing 2012 in the mist form. Here, the reference signs 2033 and 2034 in FIG. 20 show the virtual brine sprayed from the tip end nozzle parts 2030 and 2032 to one of the plate surfaces of the metal plate 2020. The remaining brine is recovered as indicated by the arrow A2 in FIGS. 19B and 19C.
In addition, although the illustration is omitted, the supply (and recovery) of the brine to each sprinkler nozzle part 2018 is carried out using a brine tank that stores brine and a brine pump that provide fluidity to brine. The brine tank and the brine pump are installed outside the flake ice production device 2010 and are connected to the flake ice production device 2010 via a brine tube (illustration is omitted) and a valve device. The brine suitable for the flake ice production device 2010 in the embodiment will be described later.
The metal plate 2020 is of a plate-type, and is formed as a rectangular flat plate, as shown by a virtual line (chain double-dashed line) in FIG. 19D and a solid line (chain double-dashed line) in FIG. 21. In the metal plate 2020, the parallel plate surfaces on the front and the back are the ice-making surfaces. For each plate surface in the metal plate 2020, one sprinkler nozzle part 2018 is provided. Two sets of (four) tip end nozzle parts 2030 and 2032 in the above-described sprinkler nozzle part 2018 are located near each plate surface in the metal plate 2020.
Copper and copper alloys with high thermal conductivity are adopted as the components (materials) of the metal plate 2020. In the embodiment, the metal plate 2020 is formed by casting, and for example, the thickness of the plate is about 30 mm. The surface of the metal plate 2020 is plated by a metal that has wear resistance (for example, chromium).
Here, the shape of the metal plate 2020 is not limited to a polygon such as a rectangle, but may be, for example, a disk shape. In addition, as the material of the metal plate 2020, it is possible to adopt aluminum, iron, or stainless steel, etc.
To the metal plate 2020, as shown in FIG. 21, a linear refrigerant tube 2036, a crank-bent refrigerant tube 2038, and a U-shaped refrigerant tube (hereinafter referred to "U-shaped tube") 2040, which serves as the folded portion, are connected. Inside the metal plate 2020, as schematically shown in FIG. 22, a number of refrigerant flow paths (also referred to as 'refrigerant passages') 2042 are formed; the structure of the refrigerant flow path 2042 and the connection structure of each of refrigerant tubes 2036, 2038 and 2040 to the metal plate 2020 will be described later.
In the metal plate 2020, two routes of refrigerant guide paths are formed by these refrigerant tubes 2036, 2038, and 2040, and the refrigerant flow paths 2042. One linear refrigerant tube 2036 and one crank-bent refrigerant tube 2038 are used for each route to form an inlet portion and an outlet portion of the refrigerant guide path. These refrigerant tubes 2036 and 2038 introduce refrigerant supplied from outside the casing 2012 as indicated by the arrows B1 and C1 in FIG. 21, and derive the refrigerant passed through the refrigerant flow paths 2042 as indicated by the arrows B2 and C2 in FIG. 21.
The metal plate 2020 and the refrigerant tubes 2036, 2038 and 2040 constitute an ice maker 2044. Though the illustration is omitted, the ice maker 2044 is connected to a compressor (freezing machine) and various valve devices via the refrigerant tube (illustration is omitted).
When the refrigerant is distributed through the metal plate 2020, both plate surfaces of the metal plate 2020 are cooled. The evaporation temperature of the refrigerant, which will be described in detail later, is, for example, -60°C. When the brine is sprayed toward the plate surface of the metal plate 2020 from the tip end nozzle parts 2030 and 2032 of the sprinkler nozzle part 2018, the brine is quickly frozen on the plate surface of the metal plate 2020 and becomes ice (hybrid ice).
In the central portion of the metal plate 2020, a round through hole (reference sign is omitted) is formed to make the drive shaft 2016 pass the through hole. As shown in FIG. 21, two arms 2046 are attached to the drive shaft 2016. The arms 2046 are disposed in a propeller-like manner at 180-degree intervals on the drive shaft 2016, and protrudes generally in the radial direction of the drive shaft 2016, being arranged almost in a straight line with each other.
The arm 2046 is equipped with a scraping tooth 2022, and the scraping teeth 2022 are arranged in a propeller-like manner around the drive shaft 2016. The scraping tooth 2022 is disposed with a cutting edge thereof facing the plate surface of the metal plate 2020. The distance between each plate surface of the metal plate 2020 and the cutting edge of the scraping tooth 2022 is about 1 mm or less (for example, 0.2 mm), which is almost the total length of the scraping tooth 2022. Each plate surface of the metal plate 2020 is provided with two sets of the arm 2046 and the scraping tooth 2022 as described above.
When the motor 2014 is driven, the drive shaft 2016 rotates, and along with the arm 2046, the scraping tooth 2022 also rotates with the cutting edge almost parallel to the plate surface of the metal plate 2020. FIG. 21 shows the arm 2046 (and the scraping tooth 2022) in the state of the horizontal position by a solid line, and the state in the vertical position by a chain double-dashed line.
Ice (hybrid ice) adheres to and accumulates on the plate surface of the metal plate 2020. For this reason, the scraping tooth 2022 displaces while hitting the ice and scrapes the ice of the metal plate 2020. The scrapped ice becomes flake ice and is stored in a flake ice storage tank (illustration is omitted) disposed below the casing 2012. As the accumulation of ice and the rotation of the scraping tooth 2022 continue, the amount of flake ice stored in the flake ice storage tank (illustration is omitted) gradually increases. In this way, the scraping tooth 2022 and the arm 2046 constitute a sweeping unit that separates the ice generated in the metal plate 2020 from the metal plate 2020 by displacement with respect to the metal plate 2020.
Here, the rotation mode of the scraping tooth 2022 may be the one continued at an angle exceeding 360 degrees (continuous rotation), or may be the one stopping for a predetermined time at every predetermined angle within 360 degrees (intermittent rotation).
As the above-described refrigerant, chlorofluorocarbon (HCFC22), hydrofluorocarbon (HFC), etc., with boiling temperature (evaporation temperature) of -60°C are used. In addition, the ice to be generated (hybrid ice) is made by solidifying the brine containing a solute so that the concentration of the solute is substantially uniform, and satisfies at least the following conditions (a) and (b):

(a) the temperature of the ice after melting completely is less than 0°C; and
(b) a rate of change of the solute concentration in an aqueous solution (brine) to be generated from the ice in the melting process is 30% or less.

The brine means an aqueous solution having a low solidifying point and containing one or more solutes. Specific examples of the brine include an aqueous solution of sodium chloride (salt water), an aqueous solution of calcium chloride, an aqueous solution of magnesium chloride, an aqueous solution of ethylene glycol, an aqueous solution of ethanol, etc.
While the thermal conductivity of the brine containing common salt as the solute (salt water) is about 0.58W/mK, the thermal conductivity of the flake ice made by freezing the brine containing common salt as the solute is about 2.2W/mK. That is to say, the thermal conductivity of the flake ice (solid) is higher than that of the brine (liquid). For this reason, flake ice (solid) can cool the items to be cooled faster.
For example, even if the brine (liquid) is stored in a container and then cooled from the outside, it is impossible to produce ice having the similar characteristics as the hybrid ice. This is considered to be caused by insufficient cooling speed. However, according to the flake ice production device 2010 shown in FIGS. 19 to 21, it is possible to produce the flake ice by the ice with high cooling capacity (hybrid ice) that can satisfy both the above conditions (a) (temperature at completion of melting is less than 0°C) and (b) (a rate of change of the solute concentration in an aqueous solution (brine) to be generated from the ice in the melting process is 30% or less).
In addition, for example, the solidifying point of an aqueous solution of sodium chloride (saturated state) is -21°C, and the solidifying point of an aqueous solution of magnesium chloride (saturated state) is -26.7°C. Therefore, in the case where aqueous solutions such as these are used as brine, when the brine adheres to the metal plate 2020, the brine is quickly frozen, and a membrane of ice (hybrid ice) is formed on the surface of the metal plate 2020.
Next, the structure of the refrigerant flow path 2042 in the metal plate 2020 and the connection structure of each of the refrigerant tubes 2036, 2038 and 2040 will be described. FIG. 22 schematically shows the structure of the ice maker 2044. In the metal plate 2020, many refrigerant flow paths 2042 are formed. FIG. 22 schematically shows only the six refrigerant flow paths 2042.
The refrigerant flow path 2042 is a linear hole formed inside the metal plate 2020. The refrigerant flow path 2042 is a hole having a round cross-section, and opens in a round shape at the end surfaces 2048 and 2049 of the metal plate 2020. The diameter (inner diameter) of the refrigerant flow path 2042 is almost constant across the length direction, and the diameter is approximately 10 mm, for example.
Furthermore, inside the metal plate 2020, the refrigerant flow paths 2042 are parallel to the plate surfaces 2050 and 2051 of the metal plate 2020 and the refrigerant flow paths 2042 extend parallel to each other. Then, the refrigerant flow paths 2042 are in a positional relationship of two rows at an oblique angle to each other, and open at each end surfaces 2048 and 2049 of the metal plate 2020.
Each of the refrigerant tubes 2036, 2038 and 2040 is joined to the metal plate 2020 to connect to the refrigerant flow path 2042. As a means of joining, brazing, etc. can be adopted. FIG. 22 shows a state in which both the linear refrigerant tube 2036 and the crank-shaped refrigerant tube 2038 are cut short, and only the straight portion of each of the refrigerant tubes 2036 and 2038 is left.
The linear refrigerant tube 2036 and the crank-shaped refrigerant tube 2038 are joined to the common end surface of the metal plate 2020 (here the end surface 2049). The opening of the refrigerant tube 2042 between both the refrigerant tubes 2036 and 2038 and the opening of the refrigerant tube 2042 at the opposite end surface 2048 are spatially connected by the U-shaped refrigerant tube 2040. The U-shaped refrigerant tube 2040 is also joined to the metal plate 2020 to by means of brazing, etc. The refrigerant flow path 2042 and the refrigerant tubes 2036, 2038, and 2040 form the refrigerant guide path in a serpentine pattern, through which the refrigerant flows.
Here, in FIG. 22, one route of the refrigerant guide path is omitted and only one route of refrigerant guide path is shown to avoid complicatedness. In addition, as described above, FIG. 22 schematizes and shows the ice maker 2044, and the illustration of the through hole through which the drive shaft 2016 penetrates is omitted.
In the inner peripheral surface (flow path surface) of each refrigerant flow path 2042, a number of groove portions 2054 drawing continuous straight lines are formed to intersect one another as schematically shown in FIG. 23. These groove portions 2054 form an asperity portion 2052, in which a number of diamond-shaped patterns are drawn, on the inner peripheral surface of the refrigerant flow path 2042. Such an asperity portion 2052 causes part of the refrigerant (for example, with an evaporation temperature of -60°C) flowing through the refrigerant flow path 2042 to collide with the wall surface having the asperity, and corners, etc. For this reason, the refrigerant flow is disturbed, and results in turbulence.
The flow of the refrigerant occurring in the refrigerant flow path 2042 is forced convection due to the fluidity provided by the pump (illustration is omitted). In the case of the forced convection, a Reynolds number determines whether the flow is laminar or turbulent. Then, by increasing the Reynolds number and generating turbulence in the refrigerant, the heat transfer coefficient can be increased as compared to the case of the laminar flow.
In other words, in this embodiment, turbulence is forcibly generated by the asperity portion 2052 of the refrigerant flow path 2042. As a result, the flow resistance to the refrigerant is increased to some extent, but an increase in the heat transfer coefficient due to turbulence is added; therefore, it is possible to improve the freezing capacity as a whole. When comparing the refrigerants with the same characteristics, the amount of cold energy obtained from the refrigerant is larger when the asperity portion 2052 is provided than when the asperity portion 2052 is not provided, and accordingly, the amount of ice that can be produced per unit time can be increased.
In addition, as disclosed in Patent Document 1 and Patent Document 2 described above, in the past, the freezing capacity has been improved by increasing the fluidity of the refrigerant. Then, the inner peripheral surface of the refrigerant flow path is processed smoothly so that the flow resistance in the refrigerant flow path is reduced (pressure loss is reduced) when the refrigerant gas is distributed.
However, in some cases, freezing machines (in this case, compressors) have a function (low-pressure cutting function) to stop operation in the case where the refrigerant pressure output from the ice maker 2044 falls below the reference value and the load of the freezing machine decreases excessively. In the case where the freezing machine is provided with the low-pressure cutting function, even if the refrigerant fluidity is increased in the ice maker 2044, there is a possibility that the flow is too smooth and the load of the freezing machine decreases, which results in low-pressure cutting in the freezing machine.
In contrast thereto, in the flake ice production device 2010 in this embodiment, the asperity portion 2052 is formed on the inner peripheral surface of the refrigerant flow path 2042, and therefore, the load of the freezing machine can be maintained to a certain level or higher and low-pressure cutting can be prevented. Normally, once the low-pressure cutting occurs in the freezing machine, it requires a lot of time to restore thereof, and the production of flake ice stops during that time. However, according to the flake ice production device 2010 of the embodiment, occurrence of such a situation can be prevented.
Processing of the groove portions 2054 can, for example, be carried out using tapping (thread cutting) technology. First, in the material that becomes the metal plate 2020, holes are formed with a drill (also referred to as "by drilling" or "by punching") and the holes are passed through. After this, from the end portion of the hole, a tap (thread-cutting tool) is screwed to form a spiral groove. The formation of the groove is carried out from both end portions of the hole. This causes the spiral grooves to cross and form a diamond-shaped continuous groove portions 2054 in the refrigerant flow path 2042, as shown in FIG. 23.
In addition, by forming an asperity portion 2052, the surface area of the refrigerant flow path 2042 increases, and the contact area between the metal plate 2020 and the refrigerant increases. From this, the amount of cold energy obtained from the refrigerant is also increased as compared to the case in which the asperity portion 2052 is not provided, and accordingly, the amount of ice that can be produced per unit time can be increased.
Note that, In the embodiment, the U-shaped refrigerant tube 2040 is brazed to the metal plate 2020 to form the folded portion of the refrigerant flow path 2042, but is not limited thereto, and, for example, a folded portion may be formed as shown in FIGS. 24 and 25. In FIGS. 24 and 25, the two refrigerant flow paths 2042 are connected via a groove-shaped connecting concave part 2056. Furthermore, the metal plate 2020 has been processed to have a countersink for crossing the two refrigerant flow paths 2042. FIGS. 24 and 25 indicate the concave (countersink portion) formed by countersink processing with a reference sign 2058. The bottom portion 2057, which is located in the depth of the connecting concave part 2056, is processed into an R shape (also referred to as "curved shape" or "cross-sectional arc shape") connecting the two refrigerant flow paths 2042. The surface shape of the wall part connecting the two refrigerant flow paths 2042 is smooth without corners.
As shown in FIG. 25, a cap 2060 formed into a round disc shape is inserted into the countersink part 2058 as indicated by the arrow D, and the cap 2060 is brazed to the metal plate 2020. Then, the end portions of the two refrigerant flow paths 2042 are blocked by the cap 2060, but the two refrigerant flow paths 2042 are continuing via the connecting concave part 2056; therefore, the two refrigerant flow paths 2042 remain spatially connected after the cap 2060 is joined. The connecting concave part 2056 serves as the folded portion of the refrigerant. In this folded portion, since the bottom portion 2057 has an R shape, it is possible to reduce the circulation resistance (flow resistance) of the refrigerant.
In the other set of refrigerant flow paths 2042, similarly, the connecting concave part 2056 and the countersink part 2058 are formed, the cap 2060 is inserted into the countersink part 2058, and thereby the cap 2060 is joined to the metal plate 2020. By forming the folded portion in this way, the U-shaped refrigerant tube 2040 (FIG. 22) becomes unnecessary.
Next, a second embodiment of the second disclosure mode will be described. Note that descriptions will be appropriately omitted about components and matters similar to those in the first embodiment. FIG. 26 schematically shows a production method of a metal plate 2070 related to the second embodiment of the second disclosure mode. The metal plate 2070 is formed by causing a first plate 2072 and a second plate 2074 to face each other, overlapping and joining thereof as indicated by the arrow E.
The first plate 2072 and the second plate 2074 are formed by casting or cutting. In addition, the first plate 2072 and the second plate 2074 have similar external dimensions, and each of which has a thickness of about 15 mm. In the first plate 2072 and the second plate 2074, groove portions 2076 and 2078, which serve as the refrigerant flow paths, are formed. The groove portions 2076 and 2078 have a number of linear portions 2080 formed in parallel with one another and U-shaped portions 2082 connecting the linear portions 2080.
Both end portions of groove portions 2076 and 2078 open in a semicircular shape (illustration is omitted) at the end surfaces of the first plate 2072 and the second plate 2074. The groove portions 2076 and 2078 are formed in a mirror-image relation to each other so that they are line symmetrical, and a single refrigerant flow path is formed by superimposing the first plate 2072 and the second plate 2074.
As shown in FIGS. 27 and 28, a number of protruding furrow portions 2084 are formed in the groove portion 2076 of the first plate 2072. Each furrow portion 2084 is formed into an arc plate shape. In addition, the furrow portion 2084 is formed integrally with the first plate 2072 and protrudes almost vertically from the inner peripheral surface (flow path surface) of the groove portion 2076 (for example, about 1 mm).
The furrow portion 2084 is oriented obliquely with the inclination angle θ to the direction in which the groove portion 2076 extends. The furrow portions 2084 are arranged parallel to each other. These furrow portions 2084 form the asperity portion 2088 in the refrigerant flow path 2086 constituted by the groove portions 2076 and 2078.
As shown in FIG. 26, by forming a metal plate by joining the half-shaped first plate 2072 and second plate 2074 having groove portions 2076 and 2078, respectively, it is possible to form the refrigerant flow path 2086 without drilling the metal plate and without the use of U-shaped refrigerant tubes 2040.
Furthermore, turbulence can be generated in the refrigerant flow path 2086 by forming the asperity portion 2088 by the furrow portions 2084. Similar to the first embodiment, it becomes possible to increase the heat transfer coefficient of the metal plate, and improve the freezing capacity. In addition, by forming the asperity portion 2088, the surface area of the refrigerant flow path 42 increases, and the contact area between the metal plate 2070 and the refrigerant increases.
Furthermore, since the furrow portion 2084 is provided obliquely with the inclination angle θ to the direction in which the groove portion 2076 extends, the flow resistance can be reduced as compared to the case in which the furrow portion 2084 is oriented perpendicular to the refrigerant flowing through the refrigerant flow path 2086 (for example, θ is closer to 90°). Then, the flow resistance to the refrigerant can be increased or decreased depending on the setting of the inclination angle θ of the furrow portion 2084.
In addition, the flow resistance can also be increased by making the protrusion amount of the furrow portions 2084 in the groove portion 2076 relatively large. By reducing the protrusion amount of the furrow portions 2084, the flow resistance can be reduced.
Note that the furrow portions 2084 may not be provided to the groove portion 2076 of the first plate 2072, but the furrow portions 2084 may be provided to the groove portion 2078 of the second plate 74. In addition, the furrow portions 2084 may be formed in both the groove portion 2076 of the first plate 2072 and the groove portion 2078 of the second plate 2074. Furthermore, the flow resistance to the refrigerant can be increased or decreased by changing various conditions such as the inclination angle θ and the protrusion amount of the furrow portion 2084, as well as the number and arrangement (interval, etc.) of the furrow portions 2084. Here, "furrow portion" can also be referred to as "fin."
Next, a third embodiment of the second disclosure mode will be described. Note that descriptions will be appropriately omitted about components and matters similar to those in the first embodiment. FIGS. 29 to 31 show a drum (metal body) 2121 provided to the flake ice production device related to a third embodiment of the second disclosure mode.
The drum 2121 is a drum-type metal plate with a vertical, cylindrical-shaped inner cylinder (inner cylinder part) 2132 and an outer cylinder (outer cylinder part) 2133 located outside the inner cylinder 2132 to surround thereof. The inner cylinder 2132 and the outer cylinder 2133 are arranged coaxially. The inner cylinder 2132 is formed by using materials such as copper and copper alloys. Between the inner cylinder 2132 and the outer cylinder 2133, a spiral refrigerant flow path 2134 is provided.
The refrigerant flow path 2134 is formed by partitioning the space between the inner cylinder 2132 and the outer cylinder 2133 by a flow path wall (flow path wall part, also referred to as "ribbon") 2136 formed into the spiral shape as shown in FIG. 29. The width of flow path wall 2136 is consistent with the distance between the inner cylinder 2132 and the outer cylinder 2133. The inner perimeter of the flow path wall 2136 is joined to the outer surface of the inner cylinder 2132, and the outer perimeter of the flow path wall 2136 is joined to the inner surface of the outer cylinder 2133.
Each end edge in the axial direction of the inner cylinder 2132 (only one is shown) is provided with an outward flange 2132a. The flange 2132a straddles the inner cylinder 2132 and the outer cylinder 2133 and closes each end portion of the refrigerant flow path 2134. Although the illustration is omitted, refrigerant is supplied to the refrigerant flow path 2134 via a freezing machine (compressor), or refrigerant tubes, etc. Then, the refrigerant flowing through the refrigerant flow path 2134 freezes the inner peripheral surface of the inner cylinder 2132.
Inside the drum 2121, although the illustration is omitted, a spraying mechanism part that sprays the brine in the centrifugal direction in a mist form, and a scraping tooth (scraper) that scrapes out the produced hybrid ice, etc. are disposed.
Of these, the spraying mechanism part is located coaxially inside the drum 2121, and sprays the brine to the inner peripheral surface of the inner cylinder 2132 while rotating around the axial center. Since the inner peripheral surface of the inner cylinder 2132 is cooled by the refrigerant flowing through the refrigerant flow path 2134, the brine attached to the inner cylinder 2132 rapidly freezes and becomes the hybrid ice.
The hybrid ice generated on the inner peripheral surface of the inner cylinder 2132 is peeled off by the scraper which moves down in the inner cylinder 2132, and falls as the flake ice. The fallen flake ice is stored in the flake ice storage tank (illustration is omitted) disposed just below.
Since the refrigerant flow path 2134 is formed in a spiral pattern as described above, the refrigerant flowing through the refrigerant flow path 2134 of the drum 2121 flows down while circling. On one side surface (top surface, flow path surface) 2138 of the flow path wall 2136, a number of protruding portions 2140, as enlarged only in part and shown in FIG. 31. The protruding portion 2140 protrudes a predetermined amount (for example, about 1 mm) inside the refrigerant flow path 2134.
As for the shape of each protruding portion 2140, various shapes can be adopted, but in the example in FIG. 31, a conical shape is adopted. Such a protruding portion2140 can be formed, for example, by press working against the flow channel wall 2136.
Furthermore, as described above, by providing the protruding portions 2140, which protrude toward the refrigerant flow path 2134 in the flow path wall 2136, the asperity portion 2142 is formed and turbulence can be generated inside the refrigerant flow path 2134. Similar to the first and second embodiments, it becomes possible to increase the heat transfer coefficient of the drum 2121, and improve the freezing capacity. In addition, by forming the asperity portion 2142, the surface area of the refrigerant flow path 2134 increases, and the contact area between the drum 2121 and the refrigerant increases.
Note that, when applying this disclosure mode to the ice slurry production device, although the illustration is omitted, the metal plate 2020, or 2070 that circulates the refrigerant, or the drum 2121 is installed in the ice slurry material production device. The ice slurry material production device is located directly above the ice storage tank where brine is stored, and the flake ice scraped from the metal plate 2020 or 2070, or the drum 2121 falls into the ice storage tank. In the ice storage tank, the brine is stirred by a mixer equipped with propeller blades, etc., and the flaked ice is mixed in the brine to produce ice slurry.
In addition, the disclosure mode can be applied to an ice slurry production device of the type that locates the metal plate 2020 or 2070, or the drum 2121 in a brine tank storing brine to be directly immersed in the brine. In this type of the ice slurry production device, the although the illustration is omitted, a freezing machine is placed outside the brine tank, for example. The freezing machine and the metal plate 2020 (or the metal plate 2070 or the drum 2121) are supported by a frame that straddles one wall of the brine tank. The brine in the brine tank is provided with fluidity by a pump, propeller blades, etc., and flake ice that has been generated on the metal plate 2020 (or the metal plate 2070 or the drum 2121) and scraped is mixed into the brine to produce the ice slurry. This type of the ice slurry production device is configured similarly to, for example, the first embodiment of the first disclosure mode (FIG. 1).
Each of the embodiments has been described above; however, the disclosure mode is not limited thereto, and various modifications within the scope of the technical idea of the present invention are available. For example, the flake ice production device and the ice slurry production device with the metal plate 2020, as shown in FIG. 22 can be referred to as a plate type. Furthermore, a type of a metal plate, in which the refrigerant path is formed by drilling, can be referred to as a drilling type. The drilling carried out in the metal plate 2020 shown in FIG. 22 can be performed not only for flat-plate metal bodies as shown in FIG. 22, but also for column-shaped or drum-shaped metal bodies, for example.
Specifically, for example, although the illustration is omitted, a metal pipe with the wall thickness of 25 mm, the diameter (outer diameter) of 500 mm, and the length (length in the axial direction) of 400 mm is punched for a number of holes in the length direction (axial direction) to form the refrigerant flow path. Since the length (length in the axial direction) of the metal pipe is 400 mm, the length of the linear refrigerant flow path is 400 mm. A linear or U-shaped refrigerant tube is joined to the metal body in which the refrigerant flow path is formed to form a refrigerant guide path. In this way, a drilling- and drum-type ice maker is formed.
Furthermore, the asperity portion can be formed by casting, and the formation of the asperity portion by casting is also applicable for the plate-type metal bodies or the drum-type metal bodies. For example, a core, which becomes the refrigerant flow path, is placed inside a plate-shaped or a drum-shaped mold to carry out casting. By providing hollows and protrusions in the core, a metal body with the asperity portion in the refrigerant flow path is formed after the material has solidified.
Other than the above, each embodiment is merely an example of embodying in implementation of the second disclosure mode, and the technical scope of the second disclosure mode should not be construed as being limited by each embodiment. That is, the present invention can be implemented in various forms without deviating from the gist or main features thereof. Each technical matter in the second disclosure mode can be applied to the first disclosure mode (FIG. 1 to 18) unless there is a hindrance.

Hereinafter, an ice-making device related to an embodiment of the third disclosure mode will be described based on the drawings. Note that an ice slurry production device as the ice-making device will be described here. FIG. 32 shows a freezing system 3010 related to the first embodiment of the third disclosure mode, and an ice slurry production device 3011 used for the freezing system 3010. The freezing system 3010 shown in FIG. 32 is configured by combining the ice slurry production device 3011, a freezing tank 3012, an aqueous solution pump 3013, etc.
The freezing system 3010 shown in FIG. 32 differs from the freezing system 10 (FIG. 1) related to the first embodiment of the first disclosure mode in that the freezing capacity is improved by plural refrigerant routes (corresponding to FIGS. 33 to 35), as will be described later. Many of the technical matters shown in FIGS. 32, 36, and 37 are in common with the freezing system 10 (FIGS. 1, 3, and 4) related to the first embodiment of the first disclosure mode.
Similar to the freezing system 10 (FIG. 1) related to the first embodiment of the first disclosure mode, the ice slurry production device 3011 of the third disclosure mode can make ice in the shape of flakes (also referred to as flake-shaped, fragment-shaped, small-lump-shaped, granular-shaped, etc.) (flake ice) by precipitating ice from, for example, raw water (for example, an ethanol aqueous solution of 50% by weight (wt%)) in the freezing tank 3012. The solidifying point of ethanol aqueous solution is, for example, about -37°C or -50°C.
The ice slurry production device 3011 includes a freezing machine 3014, a flake ice making part 3015 as an ice production unit, a refrigerant guide part 3016, etc. In addition, in the ice slurry production device 3011, the freezing machine 3014, the flake ice making part 3015, and the refrigerant guide part 3016 are mounted on a frame part 3017, which serves as a holding unit, and are integrated with one another.
The freezing machine 3014, the flake ice making part 3015, and the refrigerant guide part 3016 of the ice slurry production device 3011 constitute a freezing cycle capable of circulating a predetermined refrigerant fluid (liquid refrigerant), to thereby compress, condense, expand, and evaporate the refrigerant. Here, as a form of freezing cycle, it is possible to adopt a variety of common ones.
The refrigerant (the first refrigerant to be described later) is sent from the freezing machine 3014 to the flake ice making part 3015 via the refrigerant guide part 3016. The refrigerant guide part 3016 includes a refrigerant induction tube 3018a, which introduces the refrigerant from the freezing machine 3014 to the flake ice making part 3015, and a refrigerant derivation tube 3018b, which returns the refrigerant derived from the flake ice making part 3015 to the freezing machine 3014.
For the refrigerant induction tube 3018a or the refrigerant derivation tube 3018b, for example, a general refrigerant tube with a copper tube covered with a heat insulating material can be adopted. It is also possible to connect such refrigerant tubes via general tube couplings for the refrigerant induction tube 3018a or the refrigerant derivation tube 3018b.
In this embodiment, each end portion of the refrigerant induction tube 3018a and the refrigerant derivation tube 3018b is connected to the freezing machine 3014 and the flake ice making part 3015 via tube couplings, although detailed illustrations are omitted. In addition, the refrigerant induction tube 3018a and the refrigerant derivation tube 3018b have a curved shape so that they are bent in an inverted U-shape that protrudes upward. Furthermore, the refrigerant induction tube 3018a and the refrigerant derivation tube 3018b are similar in length and size to each other.
In addition, the inner portions of the refrigerant induction tube 3018a and the refrigerant derivation tube 3018b serve as freezing tank crossing parts 3019, which are bent in an inverted U-shape. If the ice slurry production device 3011 is installed so that the freezing machine 3014 is located outside a freezing tank 3012 (to be described later) and the flake ice making part 3015 is located inside the freezing tank 3012, then part of a wall part 3012a of the freezing tank 3012 enters the freezing tank crossing parts 3019 of the refrigerant induction tube 3018a and the refrigerant derivation tube 3018b.
For example, it is possible to adopt flexible tubes that allow operators who assemble the ice slurry production device 3011 to bend directly by hand without using tools as the refrigerant induction tube 3018a and the refrigerant derivation tube 3018b. And in this case, also, it is desirable to cover the perimeter of the flexible tube with a heat insulating material.
Furthermore, although the illustration is omitted in FIG. 32 to avoid complicatedness, in addition to a route (first refrigerant path 3029A to be described later) that causes the refrigerant (first refrigerant) to flow by the freezing machine 3014, as shown in FIG. 33, there is provided another route (second refrigerant path 3029B to be described later) that causes refrigerant of a different type (second refrigerant) to flow (FIGS. 33 and 34A).
Subsequently, as shown in FIG. 32, the flake ice making part 3015 includes a cooling part 3021, a rotational driving part 3022 as a driving unit, and a sweeping part 3023 as an ice separation unit, etc. Of these, the cooling part 3021 includes a disc part 3026 as an ice-making plate and many refrigerant tubes (U-shaped tubes 3028, etc.).
The disc part 3026 is formed of a metal plate having a rectangular (here square) plate surface (ice-making surface) and a predetermined thickness, and is fixed to the frame part 3017 (to be described later). The size (dimensions) of the disc part 3026 can be, for example, about 30 cm square in the outer shape and about 30 mm in the thickness of the plate. Here, the disc part 3026 is not limited to the rectangular shape, but may have a circular shape.
In the embodiment, the upper surface (plate surface 3026a) and the lower surface (plate surface 3026b) of the disc part 3026 are processed to be almost flat and parallel to each other. Copper and copper alloys with high thermal conductivity are adopted as the material of the disc part 3026. In the embodiment, the disc part 3026 is formed by casting. The surface of the disc part 3026 is plated by a metal that has wear resistance (for example, chromium). Here, as the material of the disc part 3026, it is possible to adopt aluminum, iron, or stainless steel, etc., in addition to copper and copper alloys.
Inside the disc part 3026, a number of refrigerant holes 3027 are formed as indicated by broken lines in FIG. 34A. The refrigerant holes 3027 extend in parallel to each other and linearly, and penetrate the disc part 3026. The cross-sectional shape of the refrigerant hole 3027 is round. These refrigerant holes 3027 are formed by drilling (punching) through the material of the disc part 3026.
In addition, a number of refrigerant tubes such as the U-shaped tubes 3028 are joined to the disc part 3026, and two routes of refrigerant paths are configured by the refrigerant holes 3027 inside the disc part 3026 and the U-shaped tubes 3028. Hereinafter, one of the refrigerant paths is referred to as "first refrigerant path" and the "first refrigerant path" is assigned with the reference sign 3029A. The other refrigerant path is referred to as "second refrigerant path" and the "second refrigerant path" is assigned with the reference sign 3029B.
In the first refrigerant path 3029A and the second refrigerant path 3029B, the first refrigerant and the second refrigerant flow in serpentine patterns, respectively. As the first refrigerant (refrigerant gas), it is possible to use R404A, R447, and R448A, etc. (the evaporation temperature is about -60°C to -45°C). In the first refrigerant path 3029A, the freezing machine 3014 provides fluidity to the first refrigerant, as shown in FIG. 33. In this case, the freezing machine 3014 functions as a fluidity imparting means for the first refrigerant.
Unlike the first refrigerant, liquefied natural gas (evaporation temperature is about - 162°C) and liquid nitrogen (evaporation temperature is about -196°C), which have the evaporation temperature lower than the evaporation temperature of the first refrigerant, can be used as the second refrigerant. In the second refrigerant path 3029B, the second refrigerant is stored in an airtightly formed second refrigerant tank 3020. Then, when a second refrigerant valve 3020a provided in the second refrigerant path 3029B is opened, the pressure of the second refrigerant vaporized in the second refrigerant tank 3020 and flow path gives the fluidity to the second refrigerant. In this case, the second refrigerant valve 3020a functions as the fluidity imparting means for the second refrigerant.
Here, the opening of the second refrigerant valve 3020a can be done manually by an operator producing the ice slurry, for example. In addition, not limited thereto, an operator who produces ice slurries may press a predetermined button to open the second refrigerant valve 3020a, for example. Furthermore, for example, it is also possible that a temperature sensor (illustration is omitted) is installed in the freezing tank 3012, and open the second refrigerant valve 3020a (open by automatic control) in the case where the temperature sensor detects that the aqueous solution Ws cooled by the first refrigerant has reached a predetermined temperature.
As a second refrigerant tank 3020, it is possible to adopt, for example, a container with a vacuum insulation structure (a container with a double structure). In addition, as the second refrigerant valve 3020a, it is possible to adopt a variety of general valve devices that can be used in flow paths for liquefied natural gas and liquid nitrogen, etc. Note that, In the embodiment, the first refrigerant and the second refrigerant are switched to supply the refrigerant to the disc part 3026, but the refrigerant supply method will be described later.
In addition, in FIG. 34A, those indicated by the reference signs 3018a and 3018b are the refrigerant induction tube 3018a and the refrigerant derivation tube 3018b in the first refrigerant path 3029A, and those indicated by the reference signs 3019a and 3019b are the refrigerant induction tube 3019a and the refrigerant derivation tube 3019b in the second refrigerant path 3029B. As described above, in FIG. 32, the illustration for the second refrigerant path 3029B is omitted, and the second refrigerant path 3029B is shown in FIGS. 33, 34A, and 35.
As shown in FIG. 34A, the direction in which the refrigerant holes 3027 extend (vertical direction in the figure) and the direction in which the refrigerant induction tube 3018a (and 3019a) and the refrigerant derivation tube 3018b (and 3019b) extend (horizontal direction in the figure) are orthogonal to each other when the disc part 3026 is viewed flat. As described above, refrigerant tubes such as U-shaped tubes 3028 are joined to the disc part 3026, and brazing can be employed as a means of joining.
In the disc part 3026, the first refrigerant paths 3029A and the second refrigerant paths 3029B are formed to overlap in a doubled fashion in the thickness direction of disc section 3026, as schematically shown in FIG. 35. Here, FIG. 35 distinguishes, by symbols, and shows the first refrigerant path 3029A and the second refrigerant path 3029B in the disc part 3026. In FIG. 35, the first refrigerant path 3029A is represented by a circle symbol and the second refrigerant path 3029B is represented by a circle symbol with a cross.
Note that the relationship between the refrigerant holes 3027 in the disc part 3026 and the refrigerant induction tube 3018a and the refrigerant derivation tube 3018b connected to the disc part 3026 is not limited to the example shown in FIG. 34A. For example, in the case where the disc part 3026 is viewed flat as shown in FIG. 34B, the direction in which the first refrigerant paths 3029A and the second refrigerant paths 3029B extend (vertical direction in the figure) and the direction in which the refrigerant induction tube 3018a (and 3019a) and the refrigerant derivation tube 3018b (and 3019b) extend (vertical direction in the figure) may be the same.
When the first refrigerant or the second refrigerant flows into the disc part 3026, the heat of the disc part 3026 is taken away and the disc part 3026 is cooled. As described above, the evaporation temperature of the first refrigerant is about -60°C to -45°C, and the evaporation temperature of the first refrigerant is about -162°C or less. Then, the solidifying point of the aqueous solution as the brine is about -38°C, which will be described in detail later. Therefore, when the aqueous solution comes into contact with the disc part 3026, the aqueous solution is quickly frozen at the disc part 3026 and becomes ice (hybrid ice).
Subsequently, the sweeping part 3023 described above includes buff support bodies 3031, as shown in FIG. 36, and each buff support body 3031 has plural buffs 3033 attached thereto. The buffs 3033 are located to face each of the plate surfaces 3026a and 3026b of the disc part 3026 in the cooling part 3021. Furthermore, in the embodiment, the buffs 3033 are disposed to contact each of the plate surfaces 3026a and 3026b of the disc part 3026 at a moderately weak pressure (low surface pressure). As will be described later, the buff 3033 has a function of sweeping the ice rose out of each of the plate surfaces 3026a and 3026b of the disc part 3026 and separating the ice from the disc part 3026 (sweeping function).
Various materials and stuffs generally used for polishing can be adopted for the buff 3033. For example, as a material for the buff 3033, urethane, other synthetic resins, metals, wool, or the like can be adopted. In addition, examples of the stuffs for the buff 3033 include sponges, foam, brushes, scrubbing brushes, resin net, non-woven fabric using various kinds of materials described above. In addition, the buff 3033 may be a metal blade with a clearance (gap) of a predetermined amount (for example, about 0.2 mm) from each of the plate surfaces 3026a and 3026b of the disc part 3026.
In addition, each buff 3033 is attached to a rod-shaped spoke 3034 provided to the buff support body 3031. The four spokes 3034 of the buff support body 3031 are arranged at 90 degree intervals to face each of the plate surfaces 3026a and 3026b of the disc part 3026. Furthermore, the buff support body 3031 is integrally coupled to a round rod-shaped rotating transmission shaft 3035.
The rotating transmission shaft 3035 penetrates the disc part 3026 in the thickness direction, avoiding the refrigerant holes 3027, to be able to rotate in the forward and reverse direction around the shaft center. The rotation transmission shaft 3035 is capable of rotational displacement with the buffs 3033 with respect to the disc part 3026 that remains stationary.
In the embodiment, as shown in FIG. 32, each buff 3033 has a feather shape (elliptical shape), and the buffs 3033 are arranged in the shape of a propeller with four blades to face each of the plate surfaces 3026a and 3026b of the disc part 3026.
Such a sweeping part 3023 is coupled to the rotational driving part 3022 (FIG. 32) via the rotating transmission shaft 3035. It is preferable to rotate the sweeping part 3023 at a rotational speed of 10 rpm to 100 rpm (revolutions per minute), for example. The rotational driving part 3022 incorporates a motor (buff driving motor), and the rotational driving part 3022 is capable of continuously (or intermittently) rotating the sweeping part 3023 in the aqueous solution Ws (the liquid level is virtually indicated by a chain double-dashed line in FIG. 1) stored in the freezing tank 3012.
Here, the rotational driving part 3022 can be a motor and a deceleration part (gear part) in one piece (geared motor). In addition, the rotational driving part 3022 is located above the liquid level of the aqueous solution Ws and is positioned to be out of the aqueous solution Ws. Furthermore, the rotational driving part 3022 is not limited to the one that rotates the sweeping part 3023 in one direction, but may be the one that rotatively reciprocates the sweeping part 23 (the one that performs reciprocating rotation of the sweeping part 23 in the forward and reverse direction).
Note that, as for the arrangement of the buffs 3033 described above, it is possible to adopt various modes, not limited to those shown in FIGS. 32 and 36. For example, the number of buffs 3033 may be less than four or five or more for each of the plate surfaces 3026a and 3026b of the disc portion 3026.
Subsequently, as shown in FIG. 32, the frame part 3017 described above is configured by, for example, joining rod-shaped components together to form a framework. As materials for the frame part 3017, general angle bars, round pipes, square pipes, or extruded materials can be adopted. In FIG. 32, the components of the frame part 3017 are drawn in a band plate shape to avoid a complicated drawing; however, it is desirable to select the materials taking into account the required strength and structure.
For joining the components of the frame part 3017, welding, screwing (including bolt tightening), etc. can be adopted. In addition, metal or synthetic resin can be adopted as the material for the frame part 3017, and of these, as the metal, a variety of general things such as steel, stainless steel, aluminum, etc. can be adopted. Furthermore, when adopting metals such as steel, various types of general surface treatments may be performed in consideration of rust prevention.
In the frame part 3017, the freezing machine 3014 and the flake ice making part 3015 are fixed, and the frame part 3017 supports the freezing machine 3014 and the flake ice making part 3015. Fixing of the freezing machine 3014 and the flake ice making part 3015 to the frame part 3017 can be carried out by common means, for example, bolt tightening or screwing. In addition, the frame part 3017 supports the flake ice making part 3015 so that the rotational driving part 3022 of the flake ice making part 3015 is out of the aqueous solution Ws.
In the case where the ice slurry production device 3011 is placed on the floor, the freezing machine 3014 is installed on the floor, sandwiching a portion of the frame part 3017 located below. In contrast thereto, the flake ice making part 3015 is supported at a position shifted from the freezing machine 3014 with a predetermined amount in the horizontal direction and slightly higher than the lower end of the freezing machine 3014.
Then, between the freezing machine 3014 and the flake ice making part 3015, the freezing tank crossing parts 3019 of the refrigerant induction tube 3018a and the refrigerant derivation tube 3018b are positioned to open downwardly. Here, in FIG. 32, part of the frame part 3017 and the freezing tank 3012 is virtually cut out as indicated by the chain double-dashed line.
It is possible to set the height from the bottom end to the top end of the ice slurry production device 3011 to about 80 cm to 90 cm. In addition, the lower end of the ice slurry production device 3011 can be set as the portion of the frame part 3017 that is in contact with the floor, and the upper end of the ice slurry production device 3011 can be set as the upper end of the rotational driving part 3022. By setting the height dimension of the ice slurry production device 3011 to about 80 cm, the height of the freezing tank 3012, which will be described later, can allow operators performing freezing to work with ease.
Next, the freezing tank 3012 and the aqueous solution Ws stored in the freezing tank 3012 will be described. In the embodiment, the freezing tank 3012 is formed in a rectangular container shape, and upper part is opened. In addition, although it is omitted in FIG. 32, the circumference of the freezing tank 3012 is enclosed by heat insulating material. Here, as heat insulating material, it is possible to adopt a variety of common ones.
In addition, each wall (including the bottom wall) of the freezer tank 3012 can be, for example, one with built-in heat insulating material or a hollow one. In the case where only each wall of the freezing tank 3012 can obtain sufficient heat insulation properties, the heat insulating material around the freezing tank 3012 can be omitted appropriately.
The aqueous solution Ws, which is indicated by the chain double-dashed line in FIG. 32, is an undiluted solution of the ice slurry (also referred to as brine). In the embodiment, an ethanol aqueous solution of a predetermined concentration (50 wt% here) is used as the aqueous solution Ws. The amount of aqueous solution Ws can be set to about 200 L (liters), for example.
Many portions of the flake ice making part 3015 of the ice slurry production device 3011 are located inside the freezer tank 3012. In other words, the freezing machine 3014 of the ice slurry production device 3011 is located outside the freezing tank 3012 and faces the wall part 3012a of one end portion in the longitudinal direction of the freezing tank 3012 from the outside.
In contrast thereto, the flake ice making part 3015 is inside the wall part 3012a, and the portion from the lowermost portion to the middle height of the flake ice making part 3015 is immersed in the aqueous solution Ws stored in the freezing tank 3012 to a predetermined amount. The disc part 3026 is located at the lowermost portion of the flake ice making part 3015, and, when the flake ice making part 3015 is immersed in the aqueous solution Ws, the entire disc part 3026 is also immersed in the aqueous solution Ws.
Subsequently, the function of the aforementioned aqueous solution pump 3013 will be described. The aqueous solution pump 3013 pumps the aqueous solution Ws, as indicated by the arrow A1 of the chain double-dashed line in FIG. 32, and the aqueous solution Ws is led to the freezing tank 3012, as indicated by the arrow A2. The aqueous solution pump 3013 then squirts the aqueous solution Ws toward the disc part 3026 of the flake ice making part 3015. Here, in FIG. 32, arrows A1 and A2 indicate the route of the aqueous solution, and the illustration of tubes is omitted.
Although it is possible to adopt various types of general pumps as the aqueous solution pump 3013, it can be considered to select the aqueous solution pump 3013 taking into account that solids (here, flake ice) are mixed with the aqueous solution Ws. In addition, the effect of preventing clogging of the flow path can be obtained by passing the aqueous solution Ws mixed with the flake ice through the tubes or the aqueous solution pump 3013. However, in the case where the flake ice is prevented from passing through the aqueous solution pump 3013, it is possible to place a filter to remove the flake ice and foreign matters from the aqueous solution
Ws at the inlet of the tube or in the front of the aqueous solution pump 3013.
The aqueous solution Ws sent from the aqueous solution pump 3013 is squirted from the nozzle part 3041 as shown in FIG. 36. The nozzle part 3041 is immersed in the aqueous solution Ws stored in the freezing tank 3012, and the aqueous solution Ws (indicated by the arrow A3 here) squirted from the nozzle part 3041 involves the aqueous solution Ws in the freezing tank 3012 in the formation of a water flow. The aqueous solution Ws (arrow A3) squirted from the nozzle part 3041 generates a flow velocity and gives momentum to the aqueous solution Ws stored in the freezing tank 12. In other words, the aqueous solution pump 3013, the nozzle part 3041, etc. constitute a water flow generation mechanism (propulsion mechanism) as a flow forming unit that forms the flow of the aqueous solution Ws.
As the nozzle part 3041, it is possible to adopt a variety of common ones. Then, as for the nozzle part 3041, examples can show the one squirting the aqueous solution Ws in a cone shape as indicated by the arrow A3, or the one squirting the aqueous solution Ws linearly, although the illustration is omitted.
The nozzle part 3041 is immersed in the aqueous solution Ws to be able to generate water flow around the disc part 3026 in the flake ice making part 3015. The water flow generated by the aqueous solution discharged from the nozzle part 41 circulates between the wall parts 3012a and 3012b located at the end portions in the length direction (longitudinal direction, left and right direction in FIG. 32) of the freezing tank 3012.
As described above, the disc part 3026 is cooled by the cold energy of the refrigerant from the freezing machine 3014; therefore, the aqueous solution Ws flowing around the disc part 3026 is cooled by the disc part 3026. Then, by sufficiently cooling the disc part 3026, the conditions are adjusted, ice precipitates on each of the plate surfaces 3026a and 26b, of the disc part 3026, and microscopic ice adheres to the disc part 3026.
As shown by the arrow A4 in FIG. 36, the buffs 3033 of the sweeping part 3023 rotate continuously and collide with the adhered ice, to sweep the ice away from the disc part 3026 to be separated (sweeping function). Since the sweeping part 3023 is rotating, the buffs 3033 intermittently pass through certain locations, and thereby the ice is separated from the disc part 3026 before growing large.
The ice separated from each of the plate surfaces 3026a and 3026b of the disc part 3026 becomes flake ice, and the flake ice is caught and dispersed in the flow of the aqueous solution Ws (indicated by the arrow A5), and the aqueous solution Ws is cooled to the solidifying point of the aqueous solution Ws.
By continuing the above-described ice adhering and sweeping of ice while giving fluidity to the aqueous solution Ws, the amount of flake ice in the aqueous solution Ws gradually increases, and the ice slurry is produced. Freezing of items to be frozen can be carried out by, for example, placing the items to be frozen in a metal basket indicated by the reference sign 3045 in FIG. 32 and immersing the items in the ice slurry by an operator holding the basket 3045.
Note that it is also possible to integrally assemble and fix the water flow generation mechanism such as the aqueous solution pump 3013 and the nozzle part 3041 to the frame part 3017. In this case, the water flow generation mechanism can be integrated into the ice slurry production device 3011. In addition, for example, the aqueous solution pump 3013 may be installed away from the frame part 3017, and only the nozzle part 3041 and the tube connected to the nozzle part 3041 may be fixed to the frame part 3017. In the case where the aqueous solution pump 3013 is installed away from the frame part 3017, the weight of the frame part 3017 including each equipment that the frame part 3017 supports can be reduced.
In addition, it is also possible to integrally assemble and fix the water flow generation mechanism such as the aqueous solution pump 3013 and the nozzle part 3041 to the frame part 3017. In this case, the water flow generation mechanism can be integrated into the ice slurry production device 3011. Furthermore, for example, the aqueous solution pump 3013 may be installed away from the frame part 3017, and only the nozzle part 3041 and the tube connected to the nozzle part 3041 may be fixed to the frame part 3017. In the case where the aqueous solution pump 3013 is installed away from the frame part 3017, the weight of the frame part 3017 including each equipment that the frame part 3017 supports can be reduced.
Next, FIG. 37A schematically shows the buff 3033 separating the ice from the disc part 3026. The buff 3033 attached to the spoke 3034 moves horizontally (rotationally) from left to right in the figure, as indicated by the arrow C of the chain double-dashed line. In the example in FIG. 37A, the buff 3033 is in contact with the plate surface 3026a on the upper side of the disc part 3026 at a moderately weak pressure (low surface pressure). The buff 3033 is made of a material with a certain degree of flexibility and has a rectangular (in this case, almost square) cross-sectional shape.
In addition, in the example shown in FIG. 37A, the buff 3033 moves while contacting the plate surface 3026a of the disc part 3026, to thereby cause friction; therefore, the cross-sectional shape thereof is deformed to be a parallelogram shape. Then, the buff 3033 beats the ice (illustration is omitted) generated on the plate surface 3026a of the disc part 3026 to exert an external force to the ice and sweep the ice away from the plate surface 3026a of the disc part 3026. Furthermore, on the surface of the opposite side of the disc part 3026 (lower plate surface 3026b), the buff 3033 sweeps the ice away by the same principle.
In the example shown in FIG. 37A, the cross-sectional shape of the buff 3033 and the cross-sectional shape of the spoke 3034 are both rectangular when the principle of sweeping by the buff 3033 is explained. But not limited to this, for example, as the spoke 3034, it is possible to adopt round bars and other shapes than the square bars. The cross-sectional shape of the buff 3033 can also be a shape other than a rectangle, and examples of the shape other than the rectangle include a triangle, a polygon, a round, and an ellipse.
Furthermore, it is possible to adopt, not only for the cross-sectional shape of each buff but also for the planar shape, various shapes other than the feather shape. Although the illustration is omitted, it is also possible that the planar shape of the buff 3033 is, for example, a round plate shape with a diameter of about 30 cm, and the number of buffs 3033 is one per one surface of the disc part 3026, and the buff 3033 rotates horizontally around the center. Furthermore, the outer diameter of the buff 3033 can be reduced to less than about 30 cm, and one or more buffs 3033 can circle while rotating.
In addition, as a further modified example, power can be transmitted from the side portion (side of the end portion) of the disc part 3026 to the buff (illustration is omitted) without making a hole to pass the rotating transmission shaft 3035 through the disc part 3026. In this case, for example, it can be considered that links (arms) of a parallel crank mechanism move alternatively and reciprocally with the disc part 3026 sandwiched by the parallel crank mechanism. By adopting such a mechanism, the sweeping part 3023 can sandwich the disc part 3026 with the mechanism and can operate like a car wiper to sweep away the ice.
In addition, a gap of a certain amount (for example, 1 mm or less to several mm) may be formed between the buff 3033 and each of the plate surfaces 3026a and 3026b of the disc part 3026 to sweep away the ice that has grown larger than the gap.
Here, fixing of the buff 3033 to the spoke 3034 can be done in various ways in general. Examples of the method of fixing include bonding, screwing, (bolt tightening), riveting, and pinching.
Note that, as shown in FIG. 37B, a metal plate (metal blade, scraping teeth) 3038 can be used instead of the buff 3033. Furthermore, other than the metal plates 3038, it is also possible to adopt a synthetic resin plate, for example. When these rigid bodies are used, as shown in FIG. 37B, it is considered that a gap H can be interposed between the rigid body and the disc part 3026. By doing this, it is possible to prevent wear of the metal plate 3038 and the disc part 3026. For the gap H, it is possible, for example, to set at less than 1 mm (0.2 mm, etc.).
In addition, by moving the metal plate 3038, etc. with the gap H, turbulence can be generated, for example, in the vicinity of the metal plate 3038, as indicted by plural arrows D in FIG. 37B. Furthermore, although the illustration is omitted, it is considered that the turbulence can also be generated in the gap H between the metal plate 3038 and the disc part 3026. Even if the metal plate 3038 is not in contact with the disc part 3026, the turbulence can be used to separate the ice from the disc part 3026. This turbulence tends to be generated by moving the metal plate 3038 quickly to some extent.
Here, fixing of the metal plate 3038 to the spoke 3034 can be done in various modes in general. Examples of the method of fixing include welding, in addition to bonding, screwing, (bolt tightening), riveting, and pinching.
Note that the buff 3033 and metal plate, etc. can be maintained by, for example, replacing at regular intervals.
Subsequently, a refrigerant supply method to the disc part 3026 will be described. As described above, R404A, etc. is used as the first refrigerant. The lower limit of the evaporation temperature setting of the R404A is -60°C. In the case where R447 or R448A is used as the refrigerant gas, setting the evaporation temperature to -60°C reduces cooling efficiency; therefore, the lower limit of the actual evaporation temperature setting is -45°C.
In order to efficiently produce the slurry using an ethanol aqueous solution (ice slurry with an ethanol aqueous solution) with a solidifying point of -37°C or -50°C, or to produce the ice slurry with an ethanol aqueous solution of -80°C or lower, refrigerants with a lower evaporation temperature should be used. Examples of the refrigerant with a lower evaporation temperature include: liquefied natural gas (evaporation temperature is about -162°C) and liquid nitrogen (evaporation temperature is about -196°C). However, since liquefied natural gas and liquid nitrogen are relatively expensive, it is desirable to use as little as possible to reduce costs.
Therefore, in the embodiment, the first refrigerant (for example, -45°C) flows in the first refrigerant path 3029A. The first refrigerant cools the disc part 3026 and gradually reduces the temperature of the aqueous solution Ws (solidifying point is -38°C). When the aqueous solution Ws reaches a predetermined temperature (for example, -30°C), the freezing machine 3014 stops supplying the first refrigerant.
Furthermore, the second refrigerant valve 3020a (FIG. 33) is opened to allow the second refrigerant (here, liquid nitrogen) to flow in the second refrigerant path 3029B. The fluidity of the second refrigerant is provided by the pressure of the nitrogen gas vaporized in the second refrigerant tank 3020. The disc part 3026 is cooled by the second refrigerant, which has an evaporation temperature much lower than the first refrigerant, and ice adhered to the disc part 3026 is mixed into the aqueous solution Ws to produce the ice slurry at a temperature lower than -38°C.
In other words, the first refrigerant is used for heat absorption in the sensible part from the ordinary temperature to -30°C (sensible heat absorption), and thereby the first cooling is performed. Furthermore, the refrigerant is switched, and for further cooling (cooling to which latent heat absorption is added), the cold energy of the second refrigerant is used to perform the second cooling. The second cooling produces low-temperature ice slurry. This makes it possible to carry out cooling in plural stages (in this case, two stages), and in the latter stage, it is possible to accelerate cooling. Such a cooling system can be referred to as, for example, a "two-stage cooling system" or a "two-stage rocket system."
In addition, since relatively expensive liquid nitrogen (liquefied natural gas, etc.) is used only for the second cooling, the cost of cooling can be reduced as compared to the case in which the liquid nitrogen is also used for cooling the sensible part.
Note that the third disclosure mode can adopt a cylindrical ice-making part (drum type) and other ice-making parts of various shapes, not limited to the plate-shaped ice-making part such as the disc part 3026. For example, as the drum type, a cylindrical ice-making part as described in Patent Document 2 (drum 21 in Patent Document 2) can be provided to the cooling part of the embodiment (equivalent to the cooling part 3021 in FIG. 32), and the ice-making part can be immersed in an aqueous solution (equivalent to the aqueous solution Ws in FIG. 32). In this case, the cylindrical ice-making part is in contact with the aqueous solution on both the outer and inner peripheral surfaces.
In the cylindrical ice-making part, although the illustration is omitted, the first refrigerant path and the second refrigerant path are formed into separate routes. In the early stage of cooling the aqueous solution, the first refrigerant (for example, the one with the evaporation temperature of -60 °C to -45 °C) flows through the first refrigerant path by a freezing machine (equivalent to the freezing machine 3014 in FIG. 32).
When the aqueous solution reaches a predetermined temperature (for example, -30°C), supply of the first refrigerant is stopped. Subsequently, the second refrigerant valve (equivalent to the second refrigerant valve 3020a in FIG. 33) is then opened and the second refrigerant (liquid nitrogen, etc.) flows into the second refrigerant path. Then, the cylindrical ice-making part is cooled by the second refrigerant, which has an evaporation temperature much lower than that of the first refrigerant. In this way, the cylindrical ice-making part can also exhibit high freezing capacity in a two-stage system.
As another embodiment, it can be considered to form a bottom portion to the cylindrical ice-making part as described above for closing the lower end, and fill the cylindrical ice-making part with the aqueous solution (or accumulate the aqueous solution in the cylindrical ice-making part), and use the cylindrical ice-making part as a tank for the aqueous solution.
Alternatively, as another embodiment, it can also be considered that a freezing tank corresponding to the freezing tank 3012 in FIG. 32 is formed using a metal and a first refrigerant path and a second refrigerant path are formed inside the wall of the freezing tank. In this case, it is possible to cool the aqueous solution in the freezing tank by flowing the first refrigerant through the first refrigerant path, and after the temperature of the aqueous solution reaches a predetermined set temperature, stop the first refrigerant and switch to the second refrigerant for further cooling.
In addition, the third disclosure mode is not limited to those for which ice slurry is produced by immersing the ice-making part in the aqueous solution or accumulating the aqueous solution in the ice-making part as explained above; it can be applied to an ice-making device that produces flake ice, such as various ice-making parts (ice-making devices) disclosed in the above-described Patent Document 1 to Patent Document 3.
In this case, the first refrigerant path and the second refrigerant path are also formed in the ice-making part. For example, spraying an aqueous solution (brine) in a mist form onto the ice-making part to bring the aqueous solution into contact with the ice-making part. The first refrigerant flows into the first refrigerant path of the ice-making part to cool the aqueous solution in the freezing tank, and then the first refrigerant is stopped and switched to the second refrigerant for performing further cooling.
Other than the above, each embodiment is merely an example of embodying in implementation of the third disclosure mode, and the technical scope of the present invention should not be construed as being limited by each embodiment. That is, the present invention can be implemented in various forms without deviating from the gist or main features thereof. Each technical matter in the third disclosure mode can be applied to the first disclosure mode (FIGS. 1 to 18) and the second disclosure mode (FIGS. 19 to 31) unless there is a hindrance.

FIG. 38 shows an ice-making device 4010, inside of which is transparently viewed, related to embodiments. FIG. 38 schematically shows an operator A with a general physique. FIG. 39 shows the ice-making device 4010 in FIG. 38 in a different angle. The ice-making device 4010 includes an ice-making tank 4012 storing brine (to be described later), and an ice-making part 4020, which is located inside the ice-making tank 4012 and can contact the brine.
In the example in FIG. 38 (and FIG. 39), the ice-making tank 4012 is supported floating from the floor 4050 by a floor-mounted cradle 4052 installed on the floor 4050. In the ice-making tank 4012, a suspension cradle 4030 is installed to be suspended from a ceiling portion 4013. The suspension cradle 4030 supports an ice-making plate (disc part 4014 in the example in FIGS. 38 and 39) and a sweeping part 4016, which are located in the ice-making tank 4012, floating from a bottom portion 4018 of the ice-making tank 4012.

<Ice-making tank 4012>

The shape of the ice-making tank 4012 is cylindrical, and the ice-making tank 4012 is made of metal such as steel. In the example in FIGS. 38 and 39, both the diameter and the height of the ice-making tank 4012 are about 2 m. The shape and size of the ice-making tank 4012 should be suitable for making ice.
In addition to a circular shape, the ice-making tank 4012 can adopt various shapes such as triangular, square, polygonal, or elliptical. The material of the ice-making tank 4012 may be stainless steel alloy or fiber reinforced plastic (FRP), etc. In addition, the ice-making tank 4012 may be a combination of two or more types from steel components, stainless steel alloy components, and FRP components, etc.
In the case where the material of the ice-making tank 4012 (including the material of components) is steel, rust prevention processing is required. As the rust prevention processing, it is possible to adopt a variety of common ones such as painting and surface treatment. Predetermined portions of the ice-making tank 4012, for example, an outer peripheral portion thereof, may be covered with a heat insulating material.
The ceiling portion 4013 of the ice-making tank 4012 is provided with an opening/closing panel 4019. The opening/closing panel 4019 has a hinge portion (illustration is omitted); thereby the opening/closing panel can be opened and closed as required. FIGS. 38 and 39 show the opening/closing panel 4019 in an open state. For example, an operator A rises onto a stepladder (illustration is omitted), etc. and opens the opening/closing panel 4019; thereby the inside of the ice-making tank 4012 can be visually recognized by the operator A through a visually recognizing opening portion 4021. It is also possible to provide a protrusion portion serving as a scaffold on the outside of the ice-making tank 4012 to make it easier for the operator A to visually recognize the inside.
A motor 4022 is installed on the outside of the ceiling portion 4013 in the ice-making tank 4012. The motor 4022 is of a type integrating a reducer (geared motor). The motor 4022 is connected to a straight-rod-shaped rotary shaft 4024, and the motor 4022 rotates the rotary shaft 4024 around the shaft center.
The motor 4022 is fixed to a detachable portion 4015 provided to the ceiling portion 4013 of the ice-making tank 4012. The detachable portion 4015 is detachably attached to the ceiling portion 4013 of the ice-making tank 4012 via plural bolts 4017. The detachment of the detachable portion 4015 from the ceiling portion 4013 of the ice-making tank 4015 also makes it possible to detach the motor 4022 and the rotary shaft 4024 from the ice-making tank 4012. Note that FIGS. 38 and 39 indicate a discharge tube by the reference sign 4026 for removing the produced ice slurry.

<Ice-making part 4020>

The ice-making part 4020 includes the disc part 4014 and the sweeping part 4016. In the example in FIGS. 38 and 39, the number of disk parts 4014 is two. In addition, in the example in FIGS. 38 and 39, a sweeping part 4016 is provided to a single disc part 4014.
The two parts 4014 are supported by the suspension cradle 4030 at a predetermined distance in the same straight line in the vertical direction (corresponding to the vertical direction in FIGS. 38 and 39). These disc parts 4014 are fixed to the suspension cradle 4030 horizontally and parallel to each other. The sweep part 4016 is connected to the rotary shaft 4024 and is rotationally displaced in the horizontal direction integral with the rotary shaft 4024. Detailed description of the disc part 4014 and the sweeping part 4016 will be given later.
The disc part 4014 and the sweeping part 4016 are integrated by the suspension cradle 4030. The upper end portion of the suspension cradle 4030 is coupled to the detachable portion 4015 provided to the ceiling portion 4013 of the ice-making tank 4012. When the detachable portion 4015 is detached from the ceiling portion 4013 of the ice-making tank 4012, the ice-making part 4020 can also be detached from the ice-making tank 4012 together with the suspension cradle 4030.
In the example shown in FIGS. 38 and 39, the suspension cradle 4030 is formed in a framework state by joining the square pipes vertically and horizontally. The positions of the suspension cradle 4030 and the detachable portion 4015 are not the center of the ceiling portion 4013 of the ice-making tank 4012, but the positions offset from the center. Here, FIG. 45B shows the position of the suspension cradle 4030 by a broken line.

«Disc part 4014»

In the example in FIGS. 38 and 39, each disc part 4014 is formed of a metal plate having a rectangular (here square) shape. The size (dimensions) of the disc part 4014 can be, for example, about 30 cm to 100 cm square in the outer shape and about 30 mm to 60 mm in the thickness of the plate. Here, the shape of the disc part 4014 is not limited to rectangular, but it is preferable to be round so that the tip end of the scraping tooth 4048 does not fall off the plate surface 4014a (or the plate surface 4014b).
As schematically shown in FIG. 41, the upper surface (plate surface 4014a) and the lower surface (plate surface 4014b) of each disc part 4014 are processed to be almost flat and parallel to each other. Copper and copper alloys with high thermal conductivity are adopted as the material of the disc part 4014. The surface of the disc part 4014 is plated by a metal that has wear resistance (for example, chromium).
Here, as the material of the disc part 4014, it is possible to adopt aluminum, iron, or stainless steel, etc., in addition to copper and copper alloys. The disc part 4014 may be formed by casting or cutting.
To the inside of the disc part 4014, as schematically shown in FIG. 42, a linear refrigerant tube 4034, and a U-shaped refrigerant tube (hereinafter referred to "U-shaped tube") 4036, which serves as the folded portion, are connected. Inside the disc part 4014, a number of linear refrigerant flow paths 4038 are formed in parallel with each other. These refrigerant flow paths 4038 are spatially connected via the U-shaped tubes 4036 to form a refrigerant guide path 4039. The refrigerant flow paths 4038 are formed by drilling through the material of the disc part 4014.
The linear refrigerant tubes 4034 form an inlet portion and an outlet portion of the refrigerant guide path 4039. The linear refrigerant tubes 4034 are connected to a refrigerant induction hose 4040 and a refrigerant derivation hose 4042 shown in FIGS. 38 and 39, and are used to introduce and derive the refrigerant (to be described later) supplied from the outside of the ice-making tank 4012.
At the central portion of the plate surfaces 4014a and 4014b of the disc part 4014, a through hole (reference sign is omitted) is formed. In FIG. 42, illustration of the through hole is omitted. As shown in FIG. 41, the rotary shaft 4024 passes through the through hole, and the rotary shaft 4024 penetrates the disc part 4014 in the thickness direction thereof. The refrigerant flow paths 4038 are formed to avoid the through hole.
The refrigerant induction hose 4040 and the refrigerant derivation hose 4042 connected to the disc part 4014 are flexible hoses having flexibility. When detaching the ice-making part 4020 from the ice-making tank 4012 via the detachable portion 4015 of the ice-making tank 4012, the refrigerant induction hose 4040 and the refrigerant derivation hose 4042 are elastically deformed to follow the movement of the ice-making part 4020, etc. The outside of the refrigerant induction hose 4040 and the refrigerant derivation hose 4042 are covered with a heat insulating material (reference sign is omitted).
The disc part 4014 is supplied with refrigerant via the refrigerant induction hose 4040. The disc part 4014 is cooled by the refrigerant, but the cooling of the disc part 4014 and ice making using the disc part 4014 will be described later.

< <Sweeping part > >

In the embodiment, the sweeping part 4016 is formed in a shape of the propeller with four blades (refer to FIGS. 38 and 39). As schematically shown in FIG. 41, the sweeping parts 4016 are located to face the plate surfaces 4014a and 4014b of the disc part 4014, respectively. Here, in FIGS. 40 and 41, the illustrations of part of (two) blades are omitted to simplify the illustrations, and only two blades are shown. In addition, in FIG. 41, only the disc part 4014 located in the lower side is shown.
The sweeping part 4016 has an arm 4046 and the scraping tooth 4048 on each blade. The arm 4046 is located at 90 degree intervals to the rotary shaft 4024. Four arms 4046 are provided to one plate surface 4014a (or plate surface 4014b) of the disc part 4014.
A single scraping tooth 4048 is attached to each arm 4046. The scraping tooth 4048 is disposed with a cutting edge thereof facing the plate surface 4014a (and 4014b) of the disc part 4014. The scraping tooth 4048 is attached to the arm 4046 to be inclined at a predetermined angle. As the material of the scraping tooth 4048, metal or a synthetic resin, etc. can be adopted.
The sweeping part 4016 rotates while facing the plate surfaces 4014a and 4014b of the disc part 4014 as the rotary shaft 4024 rotates. By rotation of the sweeping part 4016, the scraping tooth 4048 attached to the arm 4046 also rotates with the cutting edge facing the plate surface of the disc part 4014.
As will be described later, the sweeping part 4016 collides with the ice (illustration is omitted) adhered to the disc 4014 and separates the ice from the disc part 4014. The sweeping part 4016 may be provided so that, for example, as shown in FIG. 43A, the scraping tooth 4048 contacts the disc part 4014. Alternatively, for example, as shown in FIG. 43B, the sweeping part 4016 may be provided to have a clearance of a predetermined distance H (for example, about 0.2 mm) between the scraping tooth 4048 and the disc part 4014.
As shown in FIG. 43A, in the case where the sweeping part 4016 is provided to contact each of the plate surfaces 4014a and 4014b of the disc part 4014 (only the side of the plate surface 4014a is shown), the sweeping part 4016 separates the ice while being in contact with each of the plate surfaces 4014a and 4014b. The arrow C in FIG. 43A indicates the moving direction of the scraping tooth 4048.
In addition, as shown in FIG. 43B, in the case where the sweeping part 4016 is provided to have a clearance H with the disc part 4014, the sweeping part 4016 separates the ice using the turbulence (indicated by the arrow D) generated between each of the plate surfaces 4014a and 4014b and the sweeping part 4016. Even in the case where the clearance is interposed between the sweeping part 4016 and the disc part 4014, if the ice grows to the size H of the clearance or larger, the sweeping part 4016 collides with the grown ice and separates the ice from the disc part 4014. As shown in FIG. 43B, by providing the sweeping part 4016 with a clearance (gap) H between the sweeping part 4016 and the disc part 4014, wear of the scraping tooth 4048 and the disc part 4014 can be prevented.

The refrigerant guide path 4039 of the disc part 4014 is supplied with refrigerant such as liquid nitrogen. As schematically shown in Fig. 40, a refrigerant tank 4054 is installed outside the ice-making tank 4012, and the refrigerant tank 4054 forwards refrigerant through the refrigerant induction hose 4040 to the disc part 4014 in the ice-making tank 4012. As the refrigerant, in addition to liquid nitrogen, LNG (liquefied natural gas), chlorofluorocarbon (HCFC22), or hydrofluorocarbon (HFC), etc. can also be used.
The refrigerant passed through the refrigerant guide path 4039 in the disc part 4014 is returned to the refrigerant tank 4054 via the refrigerant derivation hose 4042. Here, FIG. 40 schematically shows the ice-making system 4056 including the ice-making tank 4012 and the refrigerant tank 4054, and illustrations of various kinds of equipment such as pumps used for sending the refrigerant, valve devices that control the flow, instruments (meters) that show temperature, pressure, etc. are omitted. In addition, illustrations of various kinds of equipment such as pumps, valve devices, and instruments (meters) related to the brine Ws are also omitted.
The refrigerant cools the disc part 4014 by the cold energy thereof, and the disc part 4014 cools the brine Ws flowing around. Then, by cooling the disc part 4016 by the refrigerant, the conditions are adjusted, and the ice precipitates on each of the plate surfaces 4014a and 4014b of the disc part 4014. The precipitated ice (hybrid ice) forms microscopic ice around the disc part 4014 and adheres thereto.
The adhered ice is swept away by the sweeping part 4016 and separated from the disc part 4014. The ice separated from the disc part 4014 disc becomes flake ice in the shape of flakes (also referred to as flake-shaped, fragment-shaped, small-lump-shaped, granular-shaped, etc.), and is mixed into the brine Ws. The production of the flake ice continues with the rotation of the sweeping part 4016, and the proportion of the ice in the brine Ws gradually increases. The ice slurry is produced in the ice-making tank 4012 by continuously mixing the flake ice with the brine Ws.
Here, the rotation mode of the sweeping part 4016 that separates the ice may be the one continued at an angle exceeding 360 degrees (continuous rotation), or may be the one stopping for a predetermined time at every predetermined angle within 360 degrees (intermittent rotation).

The brine Ws means an aqueous solution having a low solidifying point and containing one or more solutes. Specific examples of the brine Ws include an aqueous solution of sodium chloride (salt water), an aqueous solution of calcium chloride, an aqueous solution of magnesium chloride, an aqueous solution of ethylene glycol, an aqueous solution of ethanol, etc.
In addition, for example, the solidifying point of an aqueous solution of sodium chloride (saturated state) is -21°C, and the solidifying point of an aqueous solution of magnesium chloride (saturated state) is -26.7°C. The solidifying point of ethanol (about 50 wt%, 60 wt%) is, for example, about -37°C or -50°C. Therefore, in the case where aqueous solutions such as the above are used as the brine, when the brine adheres to the disc part 4014, the brine is quickly frozen, and a membrane of ice (hybrid ice) is formed on the surface of the disc part 4014.
The ice slurry produced in the ice 4012 is a mixture of microscopic ice and liquid. When the ice slurry is placed in the ice-making tank 4012, microscopic ice aggregates into large particles. For this reason, it is desirable to stir the ice slurry at a relatively low speed in an ice-making tank 4012. By stirring the ice slurry, it is possible to maintain a good slurry condition with small particle sizes.
FIG. 44 shows an image of the ice slurry 4058, which is in good condition, transferred to a container made of polystyrene foam and photographed. FIG. 44 shows the condition in which the ice is not aggregated, and the ice slurry 4058 is a paste-like solution with moderate viscosity. The viscosity of the ice slurry 4058 is almost uniform overall. It is desirable that such a condition of the ice slurry is maintained continuously in the ice-making tank 4012.

installation of stirring device 60>

In the ice-making tank 4012, the ice slurry is stirred by the sweeping part 4016 because the sweeping part 4016 is continuously rotating. However, only the ice slurry in the vicinity of the sweeping part 4016 is stirred. Therefore, it is difficult to stir the ice slurry as a whole by using only the sweeping part 4016.
Therefore, to stir as much ice slurry as possible in the ice-making tank 4012, as schematically shown in FIGS. 45A and 45B, it is considered to provide a stirring device 60. In the example of FIGS. 45A and 45B, the stirring device 4060 includes a screw part 4063. The screw part 4063 is located inside the ice-making tank 4012 and is located at the tip end portion of the rotary shaft 4064. The screw part 4063 is rotationally driven around the shaft center via the rotary shaft 4064 by a rotational driving part 4066, such as a motor, located outside the ice-making tank 4012. Rotation of the screw part 4063 is carried out continuously (may be intermittently).
The screw part 4063 is oriented obliquely in the ice-making tank 4012. The screw part 4063 is fixed to the ice-making tank 4012 at the angle in the vertical direction indicated by the reference sign α 1 in FIG. 45A or at the angle in the horizontal direction indicated by the reference sign α 2 in FIG. 45B. The screw part 4063 rotates to generate a flow of the ice slurry (water flow) in the ice-making tank 4012. The water flow causes the ice slurry to be stirred continuously and entirely. By providing the stirring device 4060, the ice slurry can be stirred separately from the stirring by the sweeping part 4016.
In the example in FIGS. 38 and 39, the positions of the suspension cradle 4030 and the detachable portion 4015 were not in the center of the ceiling portion 4013 of the ice-making tank 4012, but were offset from the center. As shown in FIG. 45B, the position of the stirring device 4060 is a diagonal position (also referred to as a position with a 180-degree phase shift, etc.) around the center of the ice-making tank 4012 when the ice-making tank 4012 is viewed flat.
This makes it easier to secure the installation space for the stirring device 4060. In addition, it is possible to stir the ice slurry in a good balance with respect to the circumference direction of the ice-making tank 4012. Furthermore, the flow from the stirring device 4060 to the suspension cradle 4030 along the wall surface of the ice-making tank 4012 can be symmetrically formed against the flow returning from the suspension cradle 4030 to the stirring device 4060. In addition, it is possible to effectively combine the stirring by the sweeping part 4016 and the stirring by the stirring device 4060.
In addition, by installing the stirring device 4060, it is possible to improve the diffusivity of the ice separated from the disc part 4014 and prevent ice from adhering to the sweeping part 4016. As a result, it becomes possible to continuously provide the ice slurry in good condition.

<Water-repellent coating>

The ice slurry in the ice 4012 has almost uniform viscosity as a whole (refer to FIG. 44), but in some cases, ice adheres to the sweeping part 4016 (especially the scraping tooth 4048). The ice adhesion to the sweeping part 4016 is considered to occur as follows.
Not all of the ice scraped from the disc part 4014 by the scraping tooth 4048 is immediately dispersed into the solution, but part of the ice remains in the vicinity of the disc part 4014. Since the scraping tooth 4048 is located in the vicinity of the disc part 4014, the scraping tooth 4048 is also cooled to the temperature close to the temperature of the disc part 4014. Then, ice adheres to the scraping tooth 4048 little by little, and gradually accumulates. FIG. 46 shows an image of a sweeping part 4016 with an angle of the scraping tooth different from that of the embodiment, in which ice 4068 adheres to the sweeping part 4016.
The ice 4068 accumulated in the sweeping part 4016 naturally peels off when growing to a certain extent. The peeled ice is mixed into the ice slurry as solids of a certain degree of size, which results in an uneven quality of the ice slurry. To keep the quality of the ice slurry constant, it is not preferable to include solids.
Therefore, the adhesion of ice to the sweeping part 4016 is prevented by applying a water-repellent coating (also referred to as "non-wet coating" or "slippery coating"). Adhesion of ice to the sweeping part 4016 can also be prevented by applying a water-repellent coating. By applying the water-repellent coating to the arm 4046 and the scraping tooth 4048 of the sweeping part 4016, the water repellency (non-wettability, slipperiness, etc.) of these portions can be improved.
For the water-repellent coating, a fluororesin coating can be adopted. As the fluororesin coating, it is possible to adopt a common one. By applying the fluororesin coating, it is possible to obtain sufficient non-wettability, even if the coating of fluororesin is very thin.
By applying the fluororesin coating, the coefficient of friction can be reduced to be small. In addition, the wear resistance of the sweeping part 4016 can be improved. Even in the case where the scraping tooth 4048 of the sweeping part 4016 contacts the disc part 4014 (FIG. 43A), wear of the scraping tooth 4048 and the disc part 4014 can be prevented.
Furthermore, the heat resistance (cold energy resistance) of the sweeping part 4016 can be improved. The components in the ice-making tank 4012 are exposed to low-temperature items such as the refrigerant and the brine Ws; accordingly, there is a possibility of causing low-temperature brittleness. Therefore, by applying the fluororesin coating as the water-repellent coating, occurrence of low-temperature brittleness can be prevented.
For the fluororesin coating, fluorine paint is used. As the fluorine paint, a variety of general ones can be used as long as being used in the ice-making tank 4012. Examples of fluorine paints include: PTFE (poly tetra fluoro ethylene) paints, FEP (fluorinated ethylene propylene copolymer) paints, PFA (tetra fluororo ethylene-perfluoro alkylvinyl ether copolymer) paints, PTFE/PFA composite paints, and modified paints.
The water-repellent coating may only be applied to the scraping tooth 4048 from among the arm 4046 and the scraping tooth 4048 of the sweeping part 4016. In addition, the coating may be applied to a portion other than the arm 4046 and the scraping tooth 4048. Furthermore, the water-repellent coating may only be applied to a part of each portion.
In addition, the target of the water-repellent coating is not limited to the sweeping part 4016. For example, the water-repellent coating may be applied to the disc part 4014. The water-repellent coating in this case may only be applied to a part of the disc part 4014 (for example, the plate surfaces 4014a and 4014b). In addition, the water-repellent coating may be partially applied to the plate surfaces 4014a and 4014b of the disc part 4014.
As for the U-shaped tube 4036 (FIG. 42), the U-shaped tube 4036 is strongly cooled because the refrigerant passes through thereof, and there is a possibility that ice adheres to the U-shaped tube 4036. For this reason, it is preferable to apply the water-repellent coating to the U-shaped tubes 4036 (especially on the outer peripheral surface thereof). In addition, it is preferable to apply the water-repellent coating to the linear refrigerant tubes 4034 in a similar manner.
The water-repellent coating may be applied to the inner wall surface of the ice-making tank 4012 or to the rotary shaft 4024, either entirely or partially. Furthermore, in the case of installing the stirring device 4060, for example, the water-repellent coating may be applied to the screw part 4063, the rotary shaft 4064, etc. of the stirring device 4060, either entirely or partially.
The water-repellent coating may be applied to the highest priority equipment (here, the sweeping part 4016) and other equipment (including a part thereof). In addition, the water-repellent coating may be applied to all equipment and portions having a possibility of ice adhesion. Examples of the equipment and portions having a possibility of ice adhesion include: the sweeping part 4016, the disc part 4014, the inner wall surface of the ice-making tank 4012, the rotary shaft 4024, the suspension cradle 4030, the screw part 4063 and the rotary shaft 4064 of the stirring device 4060 as described above. Of these, in particular, it is desirable to apply the water-repellent coating to the suspension cradle 4030, and the rotary shaft 4064 and the screw part 4063 of the stirring device 4060.
For coating agents used in the water-repellent coating (for example, fluorine paint), generally the coating agent itself has a low thermal conductivity; however, the film thickness is thin, and the conduction distance of the cold energy is short. Therefore, for example, in the case where the water-repellent coating is applied to the sweeping part 4016, there is almost no effect of heat transfer on the plate surfaces 4014a and 4014b of the adjacent disc part 4014.
The water-repellent coating can also be used in conjunction with the stirring by the stirring device 4060 as shown in FIGS. 45A and 45B. In this case, the stirring device 4060 increases the diffusivity of ice around the disc part 4014, and then makes use of the water repellency of the water-repellent coating. The synergistic effect of the water-repellent coating and the stirring by the stirring device 4060 maintains the ice slurry in good condition.

<Effects of invention related to embodiment

According to the embodiment described above, since the sweeping part 4016 has the water-repellent coating, it is possible to prevent ice from adhering to the sweeping part 4016. By preventing the ice from adhering to the sweeping part 4016, it is possible to prevent ice solids from mixing into the ice slurry and maintain the quality of the ice slurry. These can improve the reliability of the ice-making device 4010.
In addition, the ice-making part 4020 is fixed to the suspension cradle 4030, and the refrigerant tank 4054 is installed at a fixed position, but the suspension cradle 4030 can be removed from the ice-making tank 4012. Therefore, maintenance and inspection of the ice-making part 4020 can be carried out upon removing the suspension cradle 4030 from the ice-making tank 4012. Then, it is easy to maintain and inspect the ice-making part 4020.
The disc part 4014 supported by the suspension cradle 4030 is connected to the refrigerant tank 4054 via the refrigerant induction hoses 4040 and the refrigerant derivation hoses 4042 having flexibility. Therefore, it is possible to maintain and inspect the ice-making part 4020 without removing the refrigerant induction hoses 4040 and the refrigerant derivation hoses 4042 from the disc part 4014 or from the refrigerant tank 4054. This also makes it easier to maintain and inspect the ice-making part 4020.
In the configurations that are constantly exposed to the low temperature, such as the ice-making part 4020 and the suspension cradle 4030, there is a possibility that the low-temperature brittleness occurs. Therefore, for improving the reliability of the ice-making device 4010, it is important to make the maintenance and inspection of the ice-making part 4020 and the suspension cradle 4030 easy.
As shown in FIGS. 45A and 45B, in the case where the ice-making tank 4012 is provided with the stirring device 4060, the ice slurry can be stirred also by means other than the sweeping part 4016. This makes it possible to stir the ice slurry more wholly and improve the ice diffusivity.
Note that, in FIGS. 38 to 41, the number of disc parts 4014 is two, but the number of disc parts 4014 may be one, or three or more. In addition, it is not limited to aligning plural disc parts 4014 in the same straight line; for example, plural (two in FIGS. 38 and 39) disc parts 4014 may be shifted in the horizontal direction (corresponding to the left and right direction in FIGS. 38 and 39) to be deviated from each other.

In the example in FIG. 42, the refrigerant guide path 4039 in the disc part 4014 was formed using the U-shaped tubes 4036. However, not limited thereto, it is also possible to use a disc part 4084 as schematically shown in FIGS. 47 and 48.
Inside the disc part 4084 shown in FIG. 47, a single refrigerant guide path 4089 is formed as indicated by broken lines in FIG. 47. The refrigerant guide path 4089 is a hole formed in a serpentine pattern including linear portions extending parallel to each other and U-shaped bent portions. The disc part 4084 is provided with a through hole 4088 for passing the rotary shaft 4024. The refrigerant guide path 4089 is formed to avoid the through hole 4088.
The disc part 4084 can be produced, for example, as shown in FIG. 48. FIG. 48 shows a method of producing the disc part 4084. The disc part 4084 is formed by causing a half-shaped first plate 4092 and second plate 4093 to face each other, overlapping and joining thereof as indicated by the arrow E.
The first plate 4092 and the second plate 4093 are formed by casting or cutting. In addition, the first plate 4092 and the second plate 4093 have similar external dimensions, and each of which has a thickness of about 15 mm to 20 mm. In the first plate 4092 and the second plate 4093, groove portions 4094 and 4095, which serve as the refrigerant flow path 4089, are formed. The groove portions 4094 and 4095 have a number of linear portions 4096 formed in parallel with one another and U-shaped portions 4097 connecting the linear portions 4096.
Both end portions of groove portions 4094 and 4095 open in a semicircular shape (illustration is omitted) at the end surfaces of the first plate 4092 and the second plate 4093. The groove portions 4094 and 4095 are formed in a mirror-image relation so that they are line symmetrical to each other. The single refrigerant flow path 4089 is formed by superimposing the first plate 4092 and the second plate 4093. By forming the disc part 4084 as described above, it is possible to form the refrigerant guide path 4089 without drilling the disc part 4084 or connecting the U-shaped tubes (refer to "U-shaped tube 4036" in FIG. 42).

invention that can be extracted from embodiments of fourth disclosure mode>

From the embodiments described so far, for example, the following invention can be extracted.

(1) An ice-making device (ice-making device 4010, etc.) including: an ice slurry production tank (ice-making tank 4012, etc.) storing brine (brine Ws, etc.); and an ice production unit (ice-making part 4020, etc.) arranged inside the ice slurry production tank, the ice production unit being able to contact the brine, wherein the ice production unit includes: an ice-making plate (disc part 4014, etc.) having an ice-making surface (plate surface 4014a, 4014b, etc.); and a sweeping unit (sweeping part 4016, etc.) being displaced (rotational displacement, etc.) with respect to the ice-making surface to separate ice generated on the ice-making surface from the ice-making surface, wherein at least part (arm 4046 and scraping tooth 4048, etc.) of the sweeping unit has water-repellent coating (fluororesin coating, etc.).
This makes it possible to prevent ice from adhering to the sweeping unit and ice adhered to the sweeping unit from being mixed into the ice slurry, to thereby improve the reliability of the ice-making device.
(2) The ice slurry production device (ice-making device 4010, etc.) described in (1) above, wherein the ice-making plate is supported by a support unit (suspension cradle 4030, etc.) arranged in the ice slurry production tank, the support unit being detachably attached to the ice slurry production tank.
This makes it possible to remove the ice-making plate and the support unit from the ice slurry production tank, and makes it easier to maintain and inspect the ice-making plate and the support unit. In addition, as a result of this, it is possible to improve the reliability of the ice-making device.
(3) The ice slurry production device (ice-making device 4010, etc.) described in (1) or (2) above, wherein, in the ice slurry production tank, a confirmation portion (visually recognizing opening portion 4021, etc.) capable of visually recognizing at least one of the ice-making plate and the sweeping unit is formed.
This makes it possible to visually inspect the ice-making plate and the support unit without removing thereof from the ice slurry production tank. Then, it becomes possible to easily improve the reliability of the ice-making device.
(4) The ice slurry production device (ice-making device 4010, etc.) described in any one of (1) to (3) above, wherein plural (for example, two) sets of the ice-making plate and the sweeping unit are provided.
This makes it possible to increase efficiency in making ice.
(5) The ice slurry production device described in any one of (1) to (4) above, wherein the ice slurry production tank includes a stirring device (stirring device 4060, etc.) to stir ice slurry produced in the ice slurry production tank.
(6) An ice-making method using an ice-making device (ice-making device 4010, etc.) including an ice slurry production tank (ice-making tank 4012, etc.) storing brine (brine Ws, etc.), and an ice production unit (ice-making part 4020, etc.) arranged inside the ice slurry production tank, the ice production unit being able to contact the brine, the ice production unit including an ice-making plate (disc part 4014, etc.) with an ice-making surface (plate surface 4014a, 4014b, etc.) and a sweeping unit (sweeping part 4016, etc.) being displaced (rotational displacement, etc.) with respect to the ice-making surface to separate ice generated on the ice-making surface from the ice-making surface, the method including: separating the ice from the ice-making surface by displacing the sweeping unit, at least part of which has water-repellent coating (fluororesin coating, etc.).

This makes it possible to prevent ice from adhering to the sweeping unit and ice adhered to the sweeping unit from being mixed into the ice slurry, to thereby improve the reliability of the ice-making device.
Each embodiment related to the fourth disclosure mode has been described above.
Each embodiment is merely an example of embodying in implementation of the fourth disclosure mode, and the technical scope of the present invention should not be construed as being limited by each embodiment. That is, the present invention can be implemented in various forms without deviating from the gist or main features thereof. Each technical matter in the fourth disclosure mode can be applied to the first disclosure mode (FIG. 1 to 18), the second disclosure mode (FIGS. 19 to 31), and the third disclosure mode (FIGS. 32 to 37) unless there is a hindrance.

Reference Signs List

10, 110, 160: Freezing system
11, 111, 161: Ice slurry production device
12, 52, 54, 56: Freezing tank
13, 166: Aqueous solution pump (Flow forming unit)
14: Freezing machine
15: Flake ice making part (Ice production unit)
16: Refrigerant guide part
17: Frame part (Holding unit)
22, 122: Rotational driving part
23, 123: Sweeping part
26, 126: Disc part (Ice-making plate)
26a, 26b, 126a, 126b: Plate surface (Ice-making surface)
33: Buff (Separation unit)
38: Metal plate (Separation unit)
41: Nozzle part (Flow forming unit)
142: Water flow generation mechanism (Flow forming unit)
Ws: Aqueous solution (Brine)
2010: Flake ice production device (Ice-making device)
2020, 2070: Metal plate (Metal body)
2042, 2086, 2134: Refrigerant flow path
2052, 2088, 20142: Asperity portion
2054: Groove portion
2084: Furrow portion
20121: Drum (Metal body)
20132: Inner cylinder (Inner cylinder part)
20133: Outer cylinder (Outer cylinder part)
20136: Flow path wall (Flow path wall part)
20138: Top surface of flow path wall (Flow path surface)
20140: Protruding portion
3011: Ice slurry production device (Ice-making device)
3014: Freezing machine
3020: Second refrigerant tank
3020a: Second refrigerant valve
3026: Disc part (Ice-making unit)
3029A: First refrigerant path
3029B: Second refrigerant path
4010: Ice-making device
4012: Ice-making tank
4013: Ceiling portion
4014: Disc part
4014a, 14b: Plate surface
4015: Detachable portion
4016: Sweeping part
4017: Bolt
4019: Opening/closing panel
4020: Ice-making part
4021: Visually recognizing opening portion
4022: Motor
4024: Rotary shaft
4030: Suspension cradle
4034, 36: Refrigerant tube
4038: Refrigerant flow path
4039: Refrigerant guide path
4040: Refrigerant induction hose
4042: Refrigerant derivation hose
4046: Arm
4048: Scraping tooth
4054: Refrigerant tank
4056: Ice-making system
4058: Ice slurry
4060: Stirring device
4063: Screw part
4064: Rotary shaft
4066: Rotational driving part
4068: Ice
A: Operator
Ws: Brine

Claims

An ice-making device comprising:
an ice slurry production tank storing brine; and

an ice production unit arranged inside the ice slurry production tank, the ice production unit being able to be immersed in the brine, wherein

the ice production unit includes:
an ice-making plate circulating refrigerant, which is supplied by a freezing machine, inside thereof and including an ice-making surface, which generates ice of the brine on at least one surface thereof,;

a flow forming unit providing a flow of the brine to the ice-making surface; and

a sweeping unit being displaced with respect to the ice-making surface to separate ice generated on the ice-making surface from the ice-making surface.
The ice-making device according to claim 1, wherein the sweeping unit is arranged in a driving unit rotating or rotatively reciprocating with respect to the ice-making surface.
The ice-making device according to claim 2, wherein the ice production unit further includes a holding unit holding at least the ice-making plate and the driving unit in one piece.
The ice-making device according to any one of claims 1 to 3, wherein at least part of the sweeping unit has water-repellent coating.
An ice-making device comprising:
an ice-making unit contacting brine;

a first refrigerant path formed to pass through the ice-making unit and capable of causing a first refrigerant to flow; and

a second refrigerant path formed to pass through the ice-making unit and capable of causing a second refrigerant, which has an evaporation temperature lower than that of the first refrigerant, to flow, wherein

the second refrigerant cools the ice-making unit cooled by the first refrigerant.
The ice-making device according to claim 1, wherein the ice-making unit is immersed in the brine.
The ice-making device according to claim 5 or 6, wherein a pressure of the second refrigerant having been vaporized provides fluidity to the second refrigerant.
The ice-making device according to any one of claims 5 to 7, further comprising:
a sweeping unit being displaced with respect to an ice-making surface of the ice-making unit to separate ice generated on the ice-making surface from the ice-making surface, wherein

at least part of the sweeping unit has water-repellent coating.
An ice-making method comprising:
after passing a first refrigerant through an ice-making unit contacting brine to cool the ice-making unit, switching the first refrigerant to a second refrigerant having an evaporation temperature lower than an evaporation temperature of the first refrigerant; and

cooling the ice-making unit, which has been cooled by the first refrigerant, by the second refrigerant.
An ice-making method performed using an ice-making device including an ice-making unit contacting brine, a first refrigerant path formed to pass through the ice-making unit and capable of causing a first refrigerant to flow, and a second refrigerant path formed to pass through the ice-making unit and capable of causing a second refrigerant, which has an evaporation temperature lower than an evaporation temperature of the first refrigerant, to flow, the ice-making method comprising:
cooling the ice-making unit by the second refrigerant after cooling the ice-making unit by the first refrigerant.
An ice-making device comprising:
an ice slurry production tank storing brine; and

an ice production unit arranged inside the ice slurry production tank, the ice production unit being able to contact the brine, wherein

the ice production unit includes:
an ice-making plate having an ice-making surface; and

a sweeping unit being displaced with respect to the ice-making surface to separate ice generated on the ice-making surface from the ice-making surface, wherein

at least part of the sweeping unit has water-repellent coating.
The ice-making device according to claim 11, wherein the ice-making plate is supported by a support unit arranged in the ice slurry production tank, the support unit being detachably attached to the ice slurry production tank.
The ice-making device according to claim 11 or 12, wherein, in the ice slurry production tank, a confirmation portion capable of visually recognizing at least one of the ice-making plate and the sweeping unit is formed.
The ice-making device according to any one of claims 11 to 13, wherein a plurality of sets of the ice-making plate and the sweeping unit is provided.
The ice-making device according to any one of claims 11 to 14, wherein the ice slurry production tank includes a stirring device to stir ice slurry produced in the ice slurry production tank.
An ice-making method using an ice-making device including an ice slurry production tank storing brine, and an ice production unit arranged inside the ice slurry production tank, the ice production unit being able to contact the brine, the ice production unit including an ice-making plate with an ice-making surface and a sweeping unit being displaced with respect to the ice-making surface to separate ice generated on the ice-making surface from the ice-making surface, the ice-making method comprising:
separating the ice from the ice-making surface by displacing the sweeping unit, at least part of which has water-repellent coating.