GB2124355A

GB2124355A - Apparatus for making ice

Info

Publication number: GB2124355A
Application number: GB08310119A
Authority: GB
Inventors: Marek Straczynzki
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-04-16
Filing date: 1983-04-18
Publication date: 1984-02-15
Also published as: GB2124355B; GB8310119D0

Abstract

An ice making machine of the type including a refrigerant circuit having a compressor for a refrigerant, a condenser, a capillary tube and an eveporator (11) has a heat transfer platen (25) in thermal contact with the evaporator (11) the heat transfer platen being of substantially hemispherical shape and embossed or deep drawn to provide a plurality of recesses or cups (26) which appear as projections on the convex face of the platen and recesses in the concave face of the platen. A water spray nozzle (27) is located at the centre of curvature of the platen (25) and is adapted to spray water into contact with substantially the whole of the concave surface of the platen so that this latter, cooled by the evaporator (11), causes the formation of blocks or cubes of ice in the recesses when the refrigerating circuit is in operation. Subsequently by changing the circuit warm gas is fed to the evaporator causing the ice between the blocks and metal cup (26) forms to melt and allow the blocks to fall from the platen. <IMAGE>

Description

SPECIFICATION Apparatus for making ice The present invention relates to apparatus for making ice, and particularly but not exclusively for making ice in the form of reguiar blocks.

Apparatus for making ice including a refrigerating system which is similar in most respects to a conventional domestic refrigerator.

This includes a compressor for compressing a refrigerant gas/vapour, and a condenser which receives the compressed gas and extracts its heat as a result of the conversion of the gas to a liquid, and the liquid refrigerant is then passed to an evaporator where it evaporates, experiences a fall in temperature and withdraws heat from the surroundings. From the evaporator the cold refrigerant, now as a gas, is passed at low pressure to the compressor where its pressure is increased before it is again fed to the condenser.

In one known form of ice making apparatus the evaporator is in thermal contact with a flat plate having a plurality of downwardly facing indentations in the approximate shape of a cube.

Beneath this plate are provided a plurality of spray heads which continuously spray the underside of the plate whilst it is being cooled due to the refrigerating action of the evaporating refrigerant in the evaporator. Because of this ice forms on the surfaces of the cup-like indentations until after a predeterminable time from start-up the iceformation will have completely filled the recesses.

At this point the refrigerating cycle is stopped and the upper surface of the plate is heated in order to melt the layer of ice in contact with the under surface of the plate sufficiently to release the block or cubes of ice formed in the recesses, and these then fall away to be collected by an underlying storage container having a lateral door by means of which access can be gained to remove the formed ice cubes from time to time.

The storage container may be well insulated against heat gain, but is not usually itself cooled since it has the evaporator closely adjacent to it.

In one known ice making machine heating of the ice-formation plate is effected by passing hot water over its upper surface, whilst in another known such machine the refrigerant circuit is modified so that warm gas from the compressor flows through the evaporator thereby warming the plate which is in thermal contact with the evaporator.

Until now all ice making apparatus has utiiised a flat ice-formation plate which requires to be sprayed with a plurality of spray heads in order to receive cold water for converting into ice.

Moreover, a further disadvantage of known icemaking apparatus is the complexity of the circuits which require an unnecessary number of tubes and circuit components.

The present invention seeks to provide icemaking apparatus in which the components are simplified so as to make the most effective use of the energy available. The present invention also seeks to provide ice-making apparatus having a simplified circuit which will be simple and easy to manufacture and reliable in operation.

According to one aspect of the present invention an ice-making machine comprises a refrigerant circuit including a compressor for a refrigerant gas, a condenser for condensing the gas after leaving the compressor, a capillary tube leading from the condenser to an evaporator and a return duct for conveying the refrigerant from the evaporator back to the compressor, in which there is a heat transfer platen in thermal contact with the evaporator, at least a portion of the platen being of part-spherical shape and having a plurality of recesses therein, a water spray nozzle being located at or adjacent the centre of curvature of the part-spherical portion of the platen and being adapted to distribute water delivered thereto over substantially the whole of the surface of the said part spherical portion of the platen whereby to cause the formation of blocks or cubes of ice in the recesses therein when the refrigerating circuit is operating to extract heat from the platen through the evaporator.

In the preferred embodiment of the invention the said platen is hemispherical in shape and located in a substantially inverted position with its concave side facing downwardly whereby to allow formed ice cubes to fall therefrom by gravity when the temperature of the platen is allowed to rise.

For this purpose a timer may be provided to control operation of the apparatus for a predetermined period, after which the refrigerant circuit is stopped and the platen heated, preferably by warm gas flowing to the evaporator direct from the compressor. For this purpose a branch duct may directly interconnect the inlet to the condenser with the inlet to the evaporator, which inlet is normally fed by the capillary tube leading from the output of the condenser, possibly via a dryer and/or an accumulator. The said branch duct is preferably controlled by an appropriate valve such as a solenoid valve electrically controlled by a timer to cause the circuit to operate cyclically in a predetermined manner.

Conveniently the part-spherical or hemispherical platen is formed as a deep drawn or pressed metal plate and the evaporator is formed as a spiral coil around the convex surface of the plate in good thermal contact therewith.

The spray head at the centre of curvature of the part-spherical or hemispherical platen may constitute a plurality of nozzles each directing a jet or spray of water at a part of the concave surface of the platen, or alternatively a single nozzle having a spray pattern extending through 1 800 may be employed. The nozzle preferably projects upwardly from an underlying collection tray which collects excess water dripping from the edges of the platen, this surplus water being that which has not frozen upon contact with the platen.

Preferably this water, which will have been cooled by contact with the platen, is circulated through a short circuit via a suitable collection tank and appropriately placed pump in order to make the best use of the heat transfer properties of the platen.

One embodiment of the present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic circuit diagram of a refrigerant circuit including a spirally wound evaporator on a helical ice-formation platen; Figure 2 is a schematic side view of the water circuit showing the platen in lateral section; and Figure 3 is a partially cut away perspective view of the platen incorporating the evaporator pipes.

Referring now to the drawings, the refrigerant circuit comprises a spirally wound evaporator tube 11 the output side of which is connected to a tube 12 leading to an accumulator 13. The output from the accumulator is taken via a duct 14 to the input side of a compressor 15 which may be of conventional type. The output of the compressor 1 5 feeds a duct 1 6 which leads to the input 17 of a condenser 1 8. Adjacent the input 1 7 of the condenser 18 the duct 1 6 has a branch duct 1 9 leading via a solenoid valve 20 to a junction point 21 with a capillary tube 22 which leads from the output 23 of the condenser 1 8 via a dryer 24 and the accumulator 13.

As can be seen more particularly in Figure 3 the evaporator 11 is in the form of a spirally wound tube in thermal contact with a generally hemispherical platen 25 having a plurality of downwardly facing cup-like recesses facing into the concave region of the hemispherical platen.

The recesses 26 may be formed by pressing or deep drawing, or the platen 25 may be made by casting or moulding to incorporate the recesses 26.

The platen 25 is positioned with its concave surface facing downwardly and at its centre of curvature is located a spray head 27 which is supplied with water under pressure via a duct 28 fed by a water pump 29 immersed in a water reservoir tank 30. The water reservoir tank 30 receives water via a solenoid valve 31 from a duct 32 incorporating, if necessary, as shown in Figure 2, a pressure regulator 33 and a water filter 34.

Also in the line 32 is a shut off cock or valve 35.

Water from the line 32 flows into the reservoir tank 30 through solenoid valve 31. A constant head in the tank 30 is maintained by means of an overflow drain pipe 39. Water in the tank 30 is pumped through the duct 28 to the spray head 27 where it is sprayed from the single spray head or water distributor over the whole of the concave interior surface of the ice-formation platen 25 impinging directly on the bottom surface of the cup-like recesses 26. When the refrigerating circuit is operating these recesses are strongly cooled and the water commences to freeze on the inside of the recesses. Any water which is cooled but not frozen drains to the circular rim of the platen 25 and is collected by an underlying tray 36 having a collection channel 37 leading to a duct 38 which returns the cold water to the water reservoir tank at a position close to the inlet to the water pump 29.In this way cold water is recirculated and sprayed at the under surface of the platen 25 until the recesses 26 are entirely filled with ice. This takes a determinable time from initiation of the cycle, and this, having been determined, can be set on a timer which controls the solenoid valve 20 to open the set time after initiation of the cycle. When the valve 20 is open warm compressed gas from the compressor 1 5 flows along the duct 1 6 and, because the capillary tube 22 offers considerable resistance to its flow will automatically flow through the duct 19 and the solenoid valve 20 direct to the junction point 21 rather than flowing through the condenser 1 8 the dryer 24 and the accumulator 13.The evaporator tubing 11 is now supplied with warm compressed gas and the temperature of the platen 25 starts to rise until, again after a determinable time, the ice in contact with the plate has melted sufficiently to allow the block or cube of ice formed in each recess 26 to fall away.

The drainage plate or tray 36 is inclined at such an angle that when the water pump 29 is turned off, which preferably occurs at the same time as energization of the solenoid valve 20, the water in the tray 36 drains away and it can then act as a receptacle and guide chute for the ice cubes falling from the recesses 26 to guide these to a collection chamber (not shown).

The ice-making apparatus described hereinabove is of simpler and more economical design that conventional ice-making machines. By utilizing a hemispherical platen the whole of the spray of the spray jet from a single spray head can be received by the contact surface thereby minimizing the number of components required and maximizing the effective area cooled.

The tank 30 can be drained for cleaning purposes by removing a drain plug 40 provided in the bottom of the tank for this purpose. Periodic cleaning, to remove chalk deposits and any possible build up of algae is required every few months. This is effected by introducing a proprietory cleaner into the water in the tank 30 and running the water pump for a given time, after which the water is drained and the tank 30 and ice cube storage container (not shown) are wiped clean.

As mentioned above, the part-spherical or hemispherical platen 11 may be formed as a deep drawn or pressed metal plate with the evaporator formed as a spiral coil around the convex surface of the plate. For this purpose stainless steel may be employed. However, since stainless steel is expensive and the drawing or pressing operation is complex and expensive it may be preferable for the platen to be formed from rubber with the icecube forms inserted into it and made from copper or other suitable material. In such an alternative embodiment the ice-cube forms 26 may be of any convenient shape; for example they may be formed as cup-like elements such as hemispherical orfrusto-conical shapes, or they may be flat sides.

In another embodiment (not illustrated) the platen may be entirely made from plastics material, either as a unitary moulding or as a fabricated assembly.

Whatever manufacturing technique is employed the platen may, in addition to the hemispherical portion illustrated in the drawings, have a skirt portion which can be cylindrical dr frusto-conical or flared such that the platen as a whole has a generally bell-shape.

As shown in the drawings there are two points of contact between the evaporator pipes and the platen. This may be increased to a greater number of reduced to only one in alternative embodiments (not illustrated). For example, a single coil in contact with only the peaks of the projections 26 constituting the rear faces of the platen recesses may be provided instead of the two coils shown in Figure 3.

Claims

1. An ice-making machine comprising a refrigerant circuit including a compressor for a refrigerant gas, a condenser for condensing the gas after leaving the compressor, a capillary tube leading from the condenser to an evaporator and a return duct for conveying the refrigerant from the evaporator back to the compressor, in which there is a heat transfer platen in thermal contact with the evaporator, at least a portion of the platen being of part-spherical shape and having a plurality of recesses therein, a water spray nozzle being located at or adjacent the centre of curvature of the part-spherical portion of the platen and being adapted to distribute water delivered thereto over substantially the whole of the surface of the said part-spherical portion of the platen whereby to cause the formation of blocks or cubes of ice in the recesses therein when the refrigerating circuit is operating to extract heat from the platen through the evaporator.

2. An ice-making machine as claimed in Claim 1, in which the said platen is hemispherical in shape and located in a substantially inverted position with its concave side facing downwardly, whereby to allow formed ice cubes to fall therefrom by gravity when the temperature of the platen is allowed to rise.

3. An ice-making machine as claimed in Claim 1 or Claim 2, in which there is provided a timer for controlling the operation of the apparatus for a predetermined period, after which the refrigerant circuit is stopped and the platen heated.

4. An ice-making machine as claimed in Claim 3, in which the platen is heated by warm gas flowing to the evaporator direct from the compressor.

5. An ice-making machine as claimed in Claim 4, in which a branch duct of the refrigerant circuit directly interconnects the inlet of the condenser to the inlet of the evaporator, which inlet is normally fed by the capillary tube leading from the output of the condenser.

6. An ice-making machine as claimed in Claim 5, in which the said branch duct is controlled by a valve such as a solenoid valve electrically controlled by the timer to cause the circuit to operate cyclically in a predetermined manner.

7. An ice-making machine as claimed in any preceding claim, in which the platen is formed as a deep drawn or pressed metal plate and the evaporator is formed as a spiral coil around the convex surface of the plate in thermal contact therewith.

8. An ice-making machine as claimed in Claim 7, in which the recesses constituting the iceforming receptacles appear as projections on the convex face of the platen.

9. An ice-making machine as claimed in Claim 8, in which the evaporator coil is in thermal contact with at least the peaks of the projections on the reverse face of the platen.

10. An ice-making machine as claimed in Claim 9, in which the evaporator coil is in contact with the platen both at the peaks of the projections on the reverse face of the platen and at locations between said peaks.

11. An ice-making machine as claimed in any preceding claim in which the spray head at the centre of curvature of the part-spherical or hemispherical portion of the platen comprises a plurality of nozzles each directing a jet or spray of water at a part of the concave surface of the platen.

12. An ice-making machine as claimed in any of Claims 1 to 10, in which the spray head at the centre of curvature of the part spherical or hemispherical portion of the platen comprises a single nozzle having a spray pattern extending through substantially 1800.

13. An ice-making machine as claimed in Claim 11 or Claim 12, in which the nozzle projects upwardly from an underlying collection tray located in a position such as to collect excess water running from the edges of the platen.

14. An ice-making machine as claimed in Claim 13, in which the water collected in the said underlying collection tray is recirculated through a short circuit via a suitable collection tank and pump back to the spray head.

1 5. An ice-making machine as claimed in any preceding claim in which the platen is made of plastics material and shaped by casting or moulding.

1 6. An ice-making machine as claimed in any preceding claim, in which the said portion of the platen is substantially hemispherical.

17. An ice-making machine as claimed in Claim 16, in which the remainder of the platen constitutes a skirt portion thereof.

1 8. An ice-making machine as claimed in Claim 1 7, in which the skirt portion of the platen is generally cylindrical.

19. An ice-making machine as claimed in Claim 17, in which the skirt portion of the platen is flared such that the platen as a whole is generally bellshape.

20. An ice-making machine substantially as hereinbefore described with reference to the accompanying drawings.