GB2248678A

GB2248678A - Snow flake making apparatus

Info

Publication number: GB2248678A
Application number: GB9120419A
Authority: GB
Inventors: Malcolm George Clulow; David Frederick Winnett
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-09-25
Filing date: 1991-09-25
Publication date: 1992-04-15
Anticipated expiration: 2011-09-25
Also published as: GB9020893D0; GB2248678B; GB9120419D0

Abstract

Snow flake making apparatus is intended to produce relatively large size snow flakes for discharge into the atmosphere. An insulated chamber (4) is supplied with cold air (6) and contains water atomising nozzles (8) so that discharge of water into the chamber forms snow. The snow is caused to collect on air pervious collection means (3) in the form of a tube and the snow, collecting as snow flakes, is discharged from the collection means and from the chamber as snow flakes via discharge outlet (12). The snow is dislodged from the collection means (3) by a flow of air from a fan (10). Air discharged from the chamber (4) through outlet (14) may be recirculated. <IMAGE>

Description

SNOW FLAKE MAKING APPARATUS This invention relates to apparatus and method of snow flake making, particularly for use indoors for making realistic snow flakes artificially but the invention may also find application in an outdoor environment.

Prior snow flake making apparatus has involved the use of tall towers in which snow crystals are formed and made to float down in an airstream. The crystals agglomerate as they descend to form snow flakes which fall through a relatively small aperture.

Such apparatus is described in, for example, the United States Patent specification No. 4,809,514. However the apparatus requires a tall chamber in order to give sufficient time for snow particle growth and agglomeration if snow flakes of sufficient size, i.e. between 5mm and 20mm diameter, are to be produced. Such apparatus is tall and unsightly and only produces snow flakes over a small area.

An object of the present invention is to provide a method and apparatus for snow flake making which overcomes or reduces some or all of the disadvantages of other systems.

According to the invention snow flake making apparatus comprises a heat insulated chamber, an inlet into the chamber for admitting cold air, water atomising means for introducing water into the chamber, air pervious snow collection means movably located within the chamber, air outlet means for removing air from the chamber, and snow discharge means for discharging collected snow flakes from the collecting means and from the chamber, the water introduced to the chamber being collected as snow on the collection means and the accumulated snow in the form of snow flakes being released from the collection means and discharged from the chamber.

Preferably the snow collection means comprises a length of material formed as a tube, the snow being collected on the exterior of the tube and the tube being rotated to pass the material past the snow discharge means.

Conveniently the snow discharge means includes a fan discharging air through the air collection means to dislodge and discharge snow collected thereon.

In one arrangement the snow collection means includes guide means for guiding a length of air pervious material over a closed path to define a tube and drive means for driving the material over said path, the air inlet and atomising means being located externally of the tube and the snow discharge means including a fan discharging air through the material from within the tube to discharge the collected snow from a lower opening in the chamber.

The guide means may include air pervious drums, at least one of which is driven to move the material over said closed path.

Preferably the closed path is generally triangular, snow being collected on the collection means over two sides of the triangle and discharged over the third side by discharge of air from ducting adjacent said third side.

The water atomising means may comprise air/water nozzles or ultrasonically operated nozzle devices supplied with compressed air and water, the nozzles being maintained at temperatures above freezing to prevent the water freezing in the nozzles.

The discharge means for the collected snow is conveniently sealed from the chamber to the exterior of the snow collection means.

The invention also provides a method of making snow flakes which includes the steps of introducing cold air and water into an insulated chamber to form snow, collecting the snow on air pervious collecting means in the chamber to form snow flakes, moving the collecting means towards a discharge position, and causing the collected snow to be discharged from the collecting means and the chamber.

Further features of the invention will appear from the following description of an embodiment of the invention which is described by way of example only and with reference to the drawings, in which: Fig. 1 is a diagrammatic section through snow flake making apparatus, and Fig. 2 is a schematic drawing of an installation containing the apparatus of Fig. 1.

Referring to the drawings and firstly to Fig. 1 an insulated chamber 4 is provided, the chamber being well insulated with a heat insulation material such as polystyrene or polyurethane. The chamber has inlet openings 6 for the introduction of cold air at temperatures below OOC provided by a cooling plant.

The chamber 4 also has an air outlet opening 7 by which air is returned to the cooling plant from the chamber.

Within the chamber is located a continuous length of snow accretion or collecting material 3 which is guided over rotatable drums 1 formed of wire mesh along a triangular path.

A drive motor 2 drives one of the drums 1 to cause the material 3 to pass along the triangular path. The snow collecting material 3 allows air flow through the material and defines a large number of nucleation sites for the snow to accumulate as snow flakes.

Located above and to the sides of the material 3, within the chamber 4 are outlet nozzles 8 by which water in fine droplets is introduced into the chamber 4. The chamber 4 defines a mixing chamber 5 in which the snow crystals are formed from the droplets and the snow falls onto the material 3 over the two upper sides of the triangular path of the material 3.

The snow is caused to collect on the surfaces of the material 3 by the air flow from the inlets 6 passing through the material 3 towards the outlet 7 which lies within the space defined by the material 3.

As a result of this action snow builds up on the material 3 in a crust 9 which may be up to 10mm deep on the surface of the material.

The snow which has built up as a crust 9 on the material 3 passes along the lower part of the triangular path towards a discharge outlet 12 of the chamber 4 formed at the lower end of the chamber 4. As the material passes over the outlet 5 the snow is dislodged by a flow of air from a fan 10 discharged adjacent the outlet and through the material by a duct 11. This air flow acts as a blower by which the snow is blown off the material 3 and falls out the outlet 12 in the form of large snow flakes. The fan 10 is supplied with clean cold air from the cooling means through a duct 14 which is sealed from the mixing chamber 5 by a seal 15 having a roller which engages the outer surface of the material 13. Further similar seals 15 are provided adjacent the outlet 12.

It will be seen that air removed from the chamber 4 through the outlet 7 should contain no snow thereby avoiding the need for a filter. Snow discharged from the outlet 12 descends in a flow of cold air and, depending on the ambient air temperature, will maintain its form as it descends.

Referring now to Fig. 2 the chamber 4 of Fig. 1 is incorporated in an installation whereby cold air is supplied to the inlets 6 and to the duct 14 from a cooling coil 20 and a circulating fan 21. The cooling coil is supplied from a refrigeration plant 22 with chilled coolant. Alternatively the cooling coil may be supplied by direct expansion refrigeration. Air discharged from the chamber 4 is recirculated to the cooling coil 20 from the outlet 7.

Claims

1. Snow flake making apparatus which comprises a heat insulated chamber, an inlet into the chamber for admitting cold air, water atomising means for introducing water into the chamber, air pervious snow collection means movably located within the chamber, air outlet means for removing air from the chamber, and snow discharge means for discharging collected snow flakes from the collection means and from the chamber, the water introduced to the chamber being collected as snow on the collection means and the accumulated snow in the form of snow flakes being released from the collection means and discharged from the chamber.

2. Apparatus according to Claim 1 wherein the snow collection means comprises a length of material formed as a tube, the snow being collected on the exterior of the tube and the tube being moved to pass the material past the snow discharge means.

3. Apparatus according to Claim 1 or 2 wherein the snow discharge means includes a fan discharging air through the air collection means to dislodge and discharge snow collected thereon.

4. Apparatus according to Claim 1, 2 or 3 wherein the snow collection means includes guide means for guiding a length of air pervious material over a closed path to define a tube and drive means for driving the material along said path, the air inlet and atomising means being located externally of the tube and the snow discharge means including a fan discharging air through the material from within the tube to discharge the collected snow from a lower opening in the chamber.

5. Apparatus according to Claim 4 wherein the guide means includes air pervious drums, at least one of which is driven to move the material over said closed path.

6. Apparatus according to Claim 5 wherein the closed path is generally triangular, snow being collected on the collection means over two sides of the triangle and discharged over the third side by discharge of air from ducting adjacent said third side.

7. Apparatus according to any one of the preceding claims wherein the water atomising means comprises air/water nozzles or ultrasonically operated nozzle devices supplied with compressed air and water, the nozzles being maintained at temperatures above freezing.

8. Apparatus according to any one of the preceding claims wherein the discharge means for collected snow is sealed from the chamber to the exterior of the snow collection means.

9. In a method of making snow flakes the steps of introducing cold air and water into an insulated chamber to form snow, collecting the snow on air pervious collection means in the chamber to form snow flakes, moving the collection means towards a discharge position and causing the collected snow to be discharged from the collection means and the chamber.

10. Snow flake making apparatus substantially as described with reference to the drawings.