GB2324596A

GB2324596A - Making snow

Info

Publication number: GB2324596A
Application number: GB9703055A
Authority: GB
Inventors: Terence Arthur Benford
Original assignee: SNOWMAKERS
Current assignee: SNOWMAKERS
Priority date: 1997-02-14
Filing date: 1997-02-14
Publication date: 1998-10-28
Anticipated expiration: 2017-02-14
Also published as: GB2324596B; GB9703055D0

Abstract

In making snow, means are provided to freeze water into ice platelets. The platelets are then comminuted in the presence of a cool air flow to form snow particles. The means to comminute the platelets may comprise a revolvable plate having at least one cutting or grinding edge. The means to freeze water may comprise a rotatable roller partially submerged in a bath of water, with means to scrape the surface of the roller to remove ice platelets. Alternatively, the means to freeze water may comprise a helical scraper (16) in a annular container (15).

Description

METHOD AND APPARATUS FOR MAKING SNOW The present invention relates to a method and apparatus for producing snow. More particularly, but not exclusively, it relates to production of artificial snow of the type which may be used for creating or improving the qualities of ski-slopes.

It is known to make artificial snow by blowing air and water through seperate nozzles to generate small water drops into a cold atmosphere to form snow particles. However, this is not always convenient since a large volume of atmosphere must be kept at a temperature sufficiently low to allow the spray to form snow particles.

It is also known from e.g. European Patent Application No. 399946, to mince a block of ice into smaller particles which can be used as snow.

It is an object of the present invention to provide a method and apparatus which overcome the disadvantages of the above systems.

According to one aspect of the present invention, there is provided an apparatus for making snow comprising means to freeze water into ice platelets, means to provide a cool air flow and means so to comminute said platelets in the presence of the air flow as to form snow particles.

Preferably the means to freeze water comprises a roller containing refrigerant fluid and a bath of water, into which said roller is partially submerged, and means to scrape the surface of said roller to remove ice platelets therefrom.

Alternatively the means to freeze water may comprise an annular container through which refrigerant is recirculatable, means to distribute water over a surface thereof and means to scrape said surface to remove ice platelets therefrom.

Advantageously the means to comminute said platelets comprises a revolvable plate having at least one cutting or grinding edge.

The plate may be further provided with means to entrain the flow of air and ice platelets.

The means to entrain the flow may comprise a plurality of outstanding projections from the surface of the plate, which projections may be curved along their length.

According to another aspect of the present invitation, there is provided a method of making snow comprising the steps of providing a source of refrigerant, causing heat exchange between water and said refrigerant at a contact surface, removing platelets of ice from said contact surface, providing a flow of cool air, passing said platelets of ice together with said flow of cool air towards means to comminute said platelets, and so comminuting said platelets in the presence of the cool air flow as to produce snow particles.

Embodiments of the present invention will now be more particularly described by way of example, and with reference to the accompanying drawings, in which: Fig 1 is a schematic view of the snowmaking apparatus of the present invention; Fig 2 shows one embodiment of an ice platelet forming part of the apparatus; Fig 3 shows an alternative embodiment of an ice platelet forming part of the apparatus; Fig 4 shows schematically one version of a comminution part of the apparatus; Fig 5 shows an alternative embodiment of the comminution part of the apparatus; Fig 6 is a perspective view of a comminution plate used in the invention; and Fig 7 is a face view of the comminution plate.

Referring now to Figure 1, the system comprises a freezing system 1, through which passes refrigerant fluid, recycled via a refrigerator 2. The refrigerant fluid is passed from the refrigerator 2 via line 3 and is returned through line 4.

The freezing system includes an inlet 5 for water and an inlet 6 for air. As will be described in more detail below, platelets of ice are passed from the freezing system 1 to a hopper 7, and air may also be supplied thereto via line 8. The combined flow of ice platelets and air is passed to comminutor 9 wherein a comminutor plate, described in more detail below, is driven by electric motor 10. The resultant flow of comminuted ice and air, namely snow, is passed via line 11 to storage or to a dispersal machine.

In a first embodiment, the ice platelets may be made according to the embodiment shown in Figure 2. In this case, a refrigerant roller 12 is fed internally with refrigerant by inlet 3 and which passes through the roller 12 and exits via pipe 4 to recirculate the refrigerant fluid.

The roller 12 is located to dip in a bath 14 of continuously replenishable water, so fed as to maintain a substantially constant level. As the roller 12 rotates in the direction of arrow A in Figure 2, the water picked up on its surface freezes on the surface of the roller and a film of ice platelets formed thereon is removed by scraper blade 13.

Ice crystals are thereby delivered to a hopper 7 in which they are combined with a flow of air for further processing towards the production of snow.

In an alternative embodiment of freezing apparatus, as shown in Figure 3, the refrigerant passes from inlet 3 to outlet 4 via an annulus 15, within which water is sprayed to freeze on the inner surface thereof and which is removed therefrom by a helical scraper 16 which rotates within the annulus.

Air, cooled to a temperature of between -3 C and -20 C, preferably between -6 C and -15 C is passed into the system by means of inlet 6 and/or inlet 8, and at a speed of approximately 10 to 30 KM per hour, preferably 15 to 20 KM per hour.

The platelets are then forced into the comminution zone 9 in which a rotor blade 17, powered by electric motor 10 revolves at a speed between 2000 and 3000 rpm, preferably in the region of 2500 rpm. This speed may be variable depending on the quality or quantity of the platelets of ice being produced at the time being.

The rotor blade 17 comprises a planar surface 18 in which there are provided at least one, or two as shown, cutting edges 19. The or each of these cutting edges is set in advance of the plate surface 18 to permit comminution of ice platelets forced thereto. The rotor 17 is further provided with curved barriers adapted to direct the inflowing air and platelet mixture towards the cutting edges 19. The barriers or baffles 20 may be inclined outwardly from a central axis 21 in order to concentrate the flow of platelets and air inwardly, and may extend in advance of the plate surface 18 by 7-11 cm at their radially outermost edge.

The comminution of the platelet and air mixture produces fine particles of ice which are in fact artificial snow and this is passed through and behind the revolving plate 17 and can be stored or distributed at will.

Claims

CLAIMS:

1. An apparatus for making snow comprising means to freeze water into ice platelets, means to provide a cool air flow and means so to comminute said platelets in the presence of the air flow as to form snow particles.

2. An apparatus as claimed in Claim 1, wherein the means to freeze water comprises a rotatable roller containing refrigerant fluid and a bath for water into which said roller is partially submerged, and means to scrape the surface of said roller to remove ice platelets therefrom.

3. An apparatus as claimed in Claim 1, wherein the means to freeze water comprises an annular container through which refrigerant is recirculatable, means to distribute water over a surface thereof and means to scrape said surface to remove ice platelets therefrom.

4. An apparatus as claimed in Claim 3, wherein said surface is internal of the container annulus and said scraping means revolves within the annulus.

5. An apparatus as claimed in any one of Claims 1 to 4, wherein the means to comminute said platelets comprises a revolvable plate having at least one cutting or grinding edge.

6. An apparatus as claimed in Claim 5, wherein the plate is further provided with means to entrain the flow of air and ice platelets.

7. An apparatus as claimed in Claim 6, wherein the means to entrain the flow comprises a plurality of projections outstanding from the surface of the plate.

8. An apparatus as claimed in Claim 7, wherein the projections are curved along their length.

9. An apparatus for making snow substantially as described herein with reference to the accompanying drawings.

10. A method of making snow comprising the steps of providing a source of refrigerant, causing heat exchange between water and said refrigerant at a contact surface, removing platelets of ice from said contact surface, providing a flow of cool air, passing said platelets of ice together with said flow of cool air towards means to comminute said platelets, and so comminuting said platelets in the presence of the cool air flow as to produce snow particles.

11. A method of making snow substantially as described herein with reference to the accompanying drawings.