WO2015041543A1

WO2015041543A1 - Vertical plate freezer

Info

Publication number: WO2015041543A1
Application number: PCT/NO2014/050173
Authority: WO
Inventors: Erik Juelsen
Original assignee: Inno-Freeze As
Priority date: 2013-09-23
Filing date: 2014-09-23
Publication date: 2015-03-26
Also published as: EP3049740B1; NO336321B1; ES2723949T3; CN105556227A; DK3049740T3; CN105556227B; NO20131278A1; EP3049740A4; EP3049740A1

Abstract

The present invention is related to a vertical plate freezer comprising a number of freezing plates 1 being arranged vertically side by side with intervening freezing compartment 2. The freezing plates 1 are moveable in the longitudinal direction of the freezer, and are mutually connected to each other via intervening, releasable spacers 3 constituting sidewalls in the freezing compartment 2. The invention also concerns such spacers.

Description

VERTICAL PLATE FREEZER

The present invention relates to a vertical plate freezer known per se, having a number of freezing plates arranged vertically side by side, according to the preamble of independent claim 1 . The invention further comprises spacers to be used in such a freezer, according to the preamble of patent claim 16.

Background In traditional vertical plate freezers, a number of freezing plates are arranged after one another, in such a way that vertical freezing compartments are created between the freezing plates. The freezing compartments are limited by the freezing plates, a bottom and the walls of the freezer, eventually may the bottom and sidewalls of each freezing compartment be one unit. The freezing plates are mutually connected to each other, often by means of bolts in such a way that one may pull the plates away from each other by pulling one plate at the end of the freezer. The movement of the freezing plates are often carried out by a hydraulic actuator fastened to one of the plates at the end of the freezer and in such a way that the plates are pulled to and from each other by activating the actuator. The number of freezing plates and the distance between the plates are different from freezer to freezer, but every freezing plate is connected to adjacent freezing plates.

The freezing compartments are loaded with the material to be frozen, and then the vertical freezing plates are pushed towards each other, 5-15 mm per freezing compartment, by pushing the end plates. This is done to compress the material in the freezing compartments, and then a cooling agent is let into the freezing plates in such a way that the freezing starts, this is called contact freezing.

When the material in the freezing compartment of the freezer has reached the desired core temperature, warm gas is led into the freezing plates in such a way that a surface of the blocks of frozen material thaws towards the freezing plates, i.e. the blocks loosen from the freezing plates. The freezing plates are then pulled apart from each other in a horizontal direction, in such a way that the size of all the freezing compartments increase, as the distance between the plates increases e.g. from 100 to 120 millimetre. This is normally performed by means of the hydraulic actuator described above. Then the blocks are pushed out of the freezer by raising the bottom between the freezing plates. The sidewalls are normally fixed having a certain tapered shape giving some more clearance in the upper end so that the blocks will loosen.

Standard freezers of this kind often need up to 8 ton pressure to push the blocks out of the freezer. The reason for this is that the blocks expand when frozen, and thus there is larger pressure upon the sidewalls, and therefore one needs a large vertical force to push the blocks out of the freezer, even after defrosting.

In relation to prior art as described in NO 308870, the freezing plates and bottom are moved in relation to each other, either by lowering the bottom, or by lifting the plates in such a way that the blocks are left standing on the bottom, when the blocks are loosen from the freezing plates. The bottom may move horizontally, and moves opposite of a conveyor belt below, in such a way that the blocks are led singularly out of the freezing compartment between adjacent freezing plates, and down onto the conveyor belt.

There is however a problem that the blocks freeze to the sidewalls between the freezing plates, and that the blocks will be partly stuck when the bottom is moved in relation to the freezing plates. In this way the block may be torn, or it may be stuck between the plates and not be transported out of the freezer. In other cases it may loosen fully or partly after a while, and then cause that more blocks will come onto the conveyor belt at the same time. The following processing and/or packing presupposes that the blocks arrives one by one, and several blocks at the same time will cause delays and problems in the further treatment.

During regular operation one does not need to change the size of the freezing compartment, and thus it is not convenient to have several freezers with different size of the freezing compartment. Yet, during some seasons, larger objects should be frozen, which demands larger intervening freezing compartments, and then it is desirable to move the freezing plates in relation to each other. According to prior art a large and comprehensive rebuilding of the freezer is necessary to achieve this, and the rebuilding causes time out of operation. To increase the distance between two freezing plates one must either remove some freezing plates with accompanying hoses, or the freezer must be correspondingly longer. The solution is normally to disconnect and remove a number of freezing plates, and to adjust the distance between the remaining plates, and possibly replacing bottom and side part. Since each freezing plate is connected to heat/freezing medium this is a time consuming work and the freezer will be out of operation a long time.

Object

There is an object of the present invention to provide a vertical plate freezer wherein blocks of frozen material are loosen from all adjacent sides, before they are led out of the freezer. Further, there is an object that it should be easy to change the distance between two adjacent freezing plates in the freezer, in such a way that the freezer may be used both when small and large objects should be frozen. Finally there is an object that the freezer as such should be hygienic and easy to clean.

The invention

The objects are met by a vertical plate freezer and a spacer according to the characterizing part of patent claim 1 and 16.

A vertical plate freezer according to the present invention comprises a number of freezing plates arranged vertically side by side, with freezing compartments between, as the freezing plates are mutually connected to each other by releasable intervening spacers constituting sidewalls of the freezing compartment. The row of freezing plates and freezing compartments are the length of the freezer. The freezer comprises additionally a bottom and an actuator for moving the freezing plates to and from each other, corresponding to freezers in prior art.

With "spacer" it is, in the context of this application, meant an element bearing against a freezing plate on one side and another freezing plate on the other side, and the size of the spacer determines thus the distance between the freezing plates.

Further it is meant that two equal spacers should be placed between two freezing plates, and that a freezing compartment should be limited by the two freezing plates, the spacers and the bottom of the freezer. The size of the spacers and the distance between the spacers determines thus the size of the freezing compartment. Further, the spacers should be "releasable", meaning that they may be released from the freezing plates and removed from the freezer.

The part of a freezing plate being adjacent to a spacer, and the end of the spacer is designed with corresponding connecting devices, in such a way that the freezing plate and the spacer may be connected to each other as the connecting devices are engaging each other. In a preferred embodiment the connecting devices are designed in such a way that the freezing plate and the spacer must be moved longitudinal to each other, when installed, vertically, to engage each other.

By "corresponding connecting devices" it is in the context of this application, meant devices designed correspondingly of each other, and which makes a connection between two elements. Further it is meant that the connecting devices should be designed in such a way that when it is pulled or pushed in a freezing plate the connecting devices will pull or push the spacer, which then, via a connecting device, will pull the next freezing plate etc. In other words, the connecting devices should be strong enough to withstand the forces arising in this relation. This will be obvious to a person skilled of the art.

In a preferred embodiment the connecting devices comprise a rail and a

corresponding recess which may accommodate the rail. In order to strengthen the connection between the freezing plate and spacer as much as possible, it is an advantage that the rail and/or the recess extends along the whole or at the least parts of the contact surface between the spacer and the freezing plate.

By making the spacer releasable from the freezing plate, it is possible to replace the spacer with a larger or smaller spacer, without having to loosen/removing the freezing plates from the freezer. In this way, the size of the freezing compartments may be amended, but since the number of freezing plates is not changed and the total size of the freezer is constant, the distance between some freezing plates must be reduced when the distance between others increases and vice versa. In this way one may for instance achieve 2 large rooms and one little, which may be

advantageously when large objects should be frozen. One does not necessarily need to use the little room for freezing, it may be left empty. A rebuilding of the freezer for instance from small to larger freezing compartments will thus be

considerably easier and faster, since only the spacers are replaced.

There is another advantage if the connecting devices between freezing plate and spacer is designed in such a way that the spacer is drawn away from the freezing compartment when the freezing plates are moved from each other, in the longitudinal direction of the freezer, and that the spacers are pressed in towards the freezing compartment when the freezing plates are moved towards each other. In this way, the spacers will be drawn out from the frozen block in such a way that the block will loosen from the spacers, and the above said problems related to emptying the freezer will be avoided.

The connecting devices between the freezing plate and the spacer should preferably be similar on both sides of the freezing plate and in both ends of the spacers.

However, to achieve the above said effect, the connecting devices are not

symmetrical along the longitudinal axe of the spacers, i.e. the end facing out of the freezing compartment is not symmetrical to the end facing toward the freezing compartment.

In a preferred embodiment of the present invention, the connecting devices are shaped as a longitudinal rail and a corresponding recess, as the recess

accommodates the rail when installed. The rail preferably has a neck-part and a head-part, wherein the head-part is larger than the neck, and the recess is most narrow at an opening, in such a way that the opening of the recess may enclose the neck of the rail. The opening of the recess is larger than the cross-section of the neck-part of the rail, but not larger than a cross-section of the head-part. In this way a good connection is achieved, because the rail can not get out of the recess unless the connecting devices are moved longitudinal in relation to each other, vertically when installed. Further, the cross section of the recess must be larger than the cross section of the rail, and the proportions between these are determinant for how much the spacer is moved inwards to/outwards from the freezing compartment when the freezing plates are moved to/from each other. The neck-part is preferably

perpendicular to the freezing plate or the spacer, in such a way that the head-part is projecting perpendicular outwards, and the opening of the recess has preferably two surfaces facing each other, as the surfaces will turn against two opposite sides of the neck.

When the material to be frozen in the freezing compartments in a freezer according to the present invention, is frozen to blocks, and the blocks should be transported out of the freezer, heat is led into the freezing plates in such a way that the blocks loosen from the freezing plate. This is according to prior art, and the freezer has the same thawing time as a regular vertical freezer i.e. 4-5 min. After thawing, the plates are taken way from each other with an actuator placed horizontally in the end of the freezer, in the same way as a regular vertical freezer. The actuator will pull in the first plate, which then pulls the spacer, which then pulls the next freezing plate etc. During this process, the freezing plates are moved in relation to the bottom in such a way that the blocks loosen.

The material in the spacer should be of such kind that it does not freeze to the material placed in the freezing compartment, at the same time as it is sufficiently strong to withstand the forces arising when the freezing plates are pulled away from each other, without the spacer loosing the engagement with the freezing plate and/or becomes destroyed. When it is pulled in a freezing plate, it will pull the spacer, which then pulls the next freezing plate etc. The frozen blocks loosen both from the bottom and the spacers when the freezing plates are pulled away from each other, and this may require use of rather large forces. One example of such material, withstanding such forces, and not getting frozen to the blocks in the freezing compartment, is plastic. One may also consider embodiments where the part or parts facing the freezing compartment is coated with such a material, which will be obvious to a person skilled of the art.

Example

The invention will in the following be described with reference to a preferred embodiment shown in the enclosed figures. The example is given to illustrate the invention and should not be used to interpret the invention according to the enclosed patent claims, limiting.

Figures 1 and 2 show a vertical plate freezer according to the present invention, in perspective from above and straight from above, respectively,

Figure 3 is a section from Figure 2, and shows connecting devices between freezing plate and spacer,

Figures 4 and 5 show a spacer in perspective and cross section, respectively, and Figure 6 shows an enlarged section of a connecting device of a freezing plate. In Figure 1 and 2 it is shown a vertical plate freezer according to the present invention, comprising a number of freezing plates 1 with freezing compartments 2 between. The freezing plates are connected to each other via releasable spacers 3, as the spacers constitutes the sidewalls of the freezing compartment and which determines the size of the freezing compartment between two adjacent freezing plates. In the shown embodiments are all the freezing compartments of the same size, but this may be changed by replacing the spacers, for example one may replace a 100 millimetre spacer with a 150 millimetre spacer in every second freezing compartment, and replace a 100 mm spacer with a 50 mm spacer in the freezing compartments between. In this way one may achieve larger freezing compartments at the same time as it is avoided to remove freezing plates which is a larger operation demanding a lot of disassembling. With exception of the spacers and connections between the spacers and freezing plates, the freezer is according to freezers in prior art, and the freezer itself is thus not described any further here.

Figure 3 is an enlarged section of Figure 2, and shows spacers 3 and freezing plates 1 and the connecting devices between. The connecting devices in the shown embodiment are designed in such a way that the spacer easily can be released from the freezing plates by moving the spacer and the plate longitudinal in relation to each other, for instance by moving the spacer vertically in a vertical plate freezer. The connecting devices protrude in the shown embodiment along the whole length of the spacer and adjacent part of the freezing plate, and is designed in such a way that when the freezing plates 1 are pulled away from each other, the spacers 3 are drawn outwards from the freezing compartments 2, and when the freezing plates are pushed together, the spacers will be pulled inwards toward the freezing

compartment.

In the embodiment shown in the Figures, the connecting devices are designed as a longitudinal rail 6 on the spacer 3, and a corresponding recess 7 on the adjacent part of the freezing plate 1 , as the recess accommodates the rail when a spacer is fastened to a freezing plate. The same effect will also be achieved if the recess is in the spacer and the rail is on the freezing plate, which will be obvious to a person skilled of the art.

The spacer 3, shown in detail in Figures 4 and 5, is designed with an outer part 4 facing out of the freezing compartment and an inner part 5 facing inwards to the freezing compartment. The outer part 4 comprises connecting devices engaging corresponding connecting devices on the freezing plate 1 , and the inner part 5 is designed to give a smooth surface towards the freezing compartment 2, and further to cover the connecting devices in such a way that the material in the freezing compartment does not freeze to the connecting devices. In this way a block of the frozen material will loosen from the freezing plates 1 due to the heat being led through the freezing plates, from the bottom because the plates are moved horizontally while the bottom is standing still, and from the spacers 3 because they are drawn outwards. Since the inner part 5 of the spacer covers the connecting devices of the freezing plate, the block will loosen from all sides and stand loose on the bottom when the freezing plates are led away from each other.

In the shown embodiment, the rail is designed with a neck-part 8 and a head-part 9, wherein the head-part has a larger cross section than the neck-part. The recess 7, shown in detail in Figure 6, is designed correspondingly, as it is most narrow at an opening 10, in such a way that the opening 10 of the recess 7 may enclose the neck- part 8 of the rail 6, when the spacer is fastened to the freezing plate. The cross section y of the opening of the recess 7 is larger than the cross section x of the neck- part 8 of the rail 6 and the cross section of the recess 7 is larger than the cross section of the rail 6, as these differences in size is determinant for how much the spacer 3 may move once the freezing plates 1 are drawn away from, or led towards each other. Further, the neck-part 8 is perpendicular to the spacer 3, and the opening 10 of the recess 7 has two surfaces a', e' facing each other, and they will turn against one side each a, e of the neck-part 8 of a connecting device of a spacer 3 once the head-part 9 is engaged in the recess 7.

To achieve that the spacer 3 should be moved outwardly when the freezing plates 1 are pulled away from each other, the rail 6 slides laterally inside the recess 7, without any possibility to get out of engagement. The rail 6 and the recess 7 is thus designed with corresponding slide-surfaces b, c, b', c' and stop units d, d'. In the shown embodiment this is achieved by giving the head-part 9 of the rail 6 a slanting surface b forming a blunt angle a with the neck-part 8 on one side, and a surface d forming a right angle to the neck-part 8 on the other side. Further, the neck-part 8 is shorter on the side with the slanting surface b, than the side with the right surface d. The recess is designed accordingly, with slanting surface b' forming a blunt angle a' towards a surface a' in the opening, and a right surface d' being perpendicular to the other surface e' in the opening. In this way, the rail may slide in the recess as the slanting surfaces b, b' slides towards each other until the right surfaces d, d' are bearing against each other.

To ensure that the spacers 3 are led in towards the freezing compartment 2 when the freezing plates 1 are pushed towards each other, a surface c, c' opposite the slanting surface b, b', is slanting correspondingly in such a way that a parallel slanting surface is achieved. When the freezing plates are led towards each other, the other slanting surface c of the rail will slide inside the recess along a

corresponding slanting surface c', and lead the spacer 3 in towards the freezing compartment until a surface f of the head-part, opposite the neck-part, is bearing against a bottom f of the recess.

In the shown embodiment, the head-part of the rail has 6-sides, wherein two and two sides are parallel. It is also possible to design the head-part with 4 sides, only comprising the slanting surface b making a blunt angle a to the neck-part, the right surface d being perpendicular to the neck-part 8, the surface c being parallel to the slanting surface b and the surface f being opposite to the neck-part. The recess must then be designed correspondingly. Such an embodiment will however, be larger than a design with 6 sides and the pointing angles between the slanting and right surfaces may be broken off.

The description above may however be performed in many ways, which will be obvious to a person skilled of the art. The invention should not be limited by the preferred examples given above to illustrate the invention, as the scope of the invention is defined by the accompanying claims.

Claims

Patent claims

1 . Vertical plate freezer comprising a number of freezing plates (1 ) arranged vertically side by side with intervening freezing compartment (2), the freezing plates (1 ) are mutually connected to each other and may be moved in the longitudinal direction of the freezer, characterized in that the freezing plates (1 ) are connected to each other via intervening, releasable spacers (3) constituting sidewalls in the freezing compartment (2).

2. Freezer according to claim 1 , characterized in that adjacent surfaces of a freezing plate (2) and a spacer (3) are performed with corresponding connecting devices (6, 7), in such a way that the devices engage each other and connects the spacer to the freezing plate.

3. Freezer according to claim 2, characterized in that the connecting devices (6, 7) are performed in such a way that they engage each other when they are moved longitudinally, when installed vertically, in relation to each other.

4. Freezer according to any one of claims 2 or 3, characterized in that the connecting devices comprise a rail (6) and a corresponding recess (7) which may accommodate the rail.

5. Freezer according to claim 4, characterized in that the rail (6) and/or the recess (7) extends along the whole contact area between the spacer (3) and the freezing plate (1 ).

6. Freezer according to any one of the claims 2-5, characterized in that the connecting devices (6, 7) are designed in such a way that the spacer (3) is pulled away from the freezing compartment (2) when the freezing plates (1 ) are moved away from each other.

7. Freezer according to any one of the claims 2-6, characterized in that the connecting devices (6, 7) are designed in such a way that the spacer (3) is pushed in towards the freezing compartment (2) when the freezing plates (1 ) are moved towards each other.

8. Freezer according to claims 6 or 7, wherein the connecting devices comprise a rail and a corresponding recess, characterized in that a cross section of the recess (7) is larger than a cross section of the rail (6), and that the size-difference between these are determining for how much the spacer moves.

9. Freezer according to any one of the claims 2-8, characterized in that the connecting devices (6, 7) are equal on both sides of the freezing plate.

10. Freezer according to any one of the claims 2-9, characterized in that the connecting devices (6, 7) are asymmetric around the longitudinal axis of the spacer (3).

1 1 . Freezer according to any one of the claims 4-10, characterized in that the rail (6) has a neck-part (8) and a head-part (9), wherein the head-part (9) has larger cross section than the neck-part (8), and wherein the recess (7) is most narrow at an opening (10), in such a way that the opening (10) may enclose the neck (8), as the opening (10) is larger than the cross section of the neck-part (8).

12. Freezer according to claim 1 1 , characterized in that the neck-part (8) is perpendicular to the freezing plate (1 ) or the spacer (3), and that the opening (10) to the recess (7) has two surfaces (a', e') turning against each other, as the surfaces should bear against the neck-part of the rail.

13. Freezer according to claim 12, characterized in that the head-part (9) has a surface (b) making a blunt angle (a) with the neck-part (8), and a surface (d) making a right angle with the neck-part (8), and in that the recess is designed with

corresponding surfaces (b\ d').

14. Freezer according to claim 12, characterized in that the neck (8) is shorter on the side where the head-part has the surface (b) making a blunt angle (a) with the neck-part than the side where the head-part has the surface (d) making a right angle.

15. Freezer according to claims 13 or 14, characterized in that the head-part (9) further comprises a surface (c) being opposite and parallel to the surface (b), and a surface (f) being opposite and parallel with the surface (d), and in that the recess is designed with corresponding surfaces (c\ f).

16. Spacer to be used in a freezer according to any one of the claims 1 -15,

characterized in that the spacer (3) makes a releasable sidewall of the freezing compartment.

17. Spacer according to claim 16, characterized by comprising connecting devices (6) for engaging adjacent freezing plates (1 ).

18. Spacer according to claims 16 or 17, characterized by comprising an inner (5) and an outer part (4), where the outer part (4) comprises the connecting devices (6), and the inner part turns against the freezing compartment.

19. Spacer according to any one of the claims 16-18, characterized in that it is made of plastic.