WO2003087684A1

WO2003087684A1 - Ice machine

Info

Publication number: WO2003087684A1
Application number: PCT/SE2003/000582
Authority: WO
Inventors: Jörgen LARSSON
Original assignee: IGLOOLUX AB
Current assignee: IGLOOLUX AB
Priority date: 2002-04-15
Filing date: 2003-04-10
Publication date: 2003-10-23
Anticipated expiration: 2004-10-15
Also published as: SE0201141D0; AU2003224530A1

Abstract

Device for producing ice cubes comprising an arrangement (5, 6, 9, 10) and a pump for supplying a fluid to a body (7) with a first and a second side, which body (7) on its first side is fitted at least one Peltier element (11, 12) for thermo-electric refrigeration of the body (7). The fluid delivering arrangement (5, 6, 9, 10) and the body (7) are so arranged relative to each other that the fluid is supplied dispersed under pressure to the second side of the body (7).

Description

ICE MACHINE

The present invention concerns a portable ice machine according to the preamble to claim 1.

Today, there are several means of producing ice cubes. Many of these generate refrigeration by means of a compressor and a refrigerant that freezes the water to ice in forms. Another method is described in the US patent 4,154,63. Water freezes to ice on top of a flat element that is inclined more the thicker the ice becomes. Once the ice has reached the desired thickness, the flat element will be heated so that the ice will come loose from the flat element. As it comes loose, it will slide onto a net of narrow pipes. These pipes contain the heated refrigerant that was previously used for refrigeration. As the layer of ice lands on the net of pipes, it will melt as it rests on the pipes whereby the ice cubes are cut out and fall down into a container. The disadvantages of these methods are that the compressor works with a relatively high level of noise, the device is relatively large and heavy and that a refrigerant such as Freon or ammonia must be used. Yet another method is described in the US patent 4,055,053. Here, the ice cubes are made inside a water container. Several ice cube forms are arranged in the bottom of the water container and connected to a Peltier element. The water in the forms is frozen to ice. Once the ice cubes have attained the desired thickness, the current will be cut or reversed, whereby the ice cubes come loose from the forms and float to the surface. The process will start over in conjunction with the ice cubes coming loose. One disadvantage of this method is that the ice cubes are kept in water, which limits the time they can be stored. The device also takes up a relatively large space.

One object of the present invention is to avoid these disadvantages in that the device is compact and thereby portable, takes up a small space, contains few moving parts and thereby maintains a low noise level, provides ice cubes without any turbidity and offers the ability to store the ice cubes for long periods.

This object can be achieved by the present invention exhibiting the distinctive features and characteristics specified in claim 1.

At least one Peltier element is arranged to one side of an inclined flat element possessing g ood thermal conductivity, such as aluminium. At the bottom of the device is arranged a water tank with pump that continually circulates the water through the entire device. The water is led to a pair of jets directed towards the other side of the flat element, whereby water is sprayed against the other side of the flat element. The water successively freezes to form a cake of ice. Once the desired thickness has been attained, the flat element is heated and the cake of ice falls onto a net of taut wires. The wires are electrically heated and melt the ice, whereby the cake of ice is cut into ice cubes. The ice cubes fall into a container in which the temperature is kept close to freezing point but not below. This means the ice cubes can be kept for longer without freezing to each other.

The invention is described more fully in the following with reference to the attached drawings, which illustrate examples of selected embodiments, where fig. 1 shows an ice machine according to the invention assembled in one unit fig. 2 shows an ice machine in partial cross section fig. 3 shows an exploded view of an ice machine in accordance with the invention

In accordance with the figures, the ice machine 1 comprises a box 2 with top part 3 and bottom part 4 that are insulated to prevent heat from entering and cold from leaking out of the box 2. The box 2 is made of plastic to accomplish low weight. The bottom part 4 of the box 2 also acts as a water tank 4 to which is connected a pump (not shown). The pump is arranged to be able to draw out all the water and avoid the risk of overfilling the tank. The water is pumped from the water tank 4 via a hose (not shown) to at least one pair of n ozzles 5 , 6 d irected towards a flat e lement 7 , the b ottom of which 8 i s s prayed. T he nozzles 5, 6 are made of a suitable material, such as plastic or metal, and each comprise an opening 9, 10. The bottom part 4 is arranged with an inclined section to which the nozzles are connected. This enables the openings 5, 6 of the nozzles 9, 10 to be directed towards the bottom 8 of the flat element 7. Water is pumped under pressure into the nozzles 5, 6, the openings 9, 10 of which have been given a dimension in relation to the pressure so that the water is supplied to the flat element 7 in a dispersed form. This can be compared with a common pump spray bottle with adjustable nozzle that provides a fine cloud of spray. The water can well be sprayed at intervals so that one layer of water has time to freeze before the next interval is started. The material used and the distance between the nozzles 5, 6 and the flat element 7 is chosen so that the risk of freezing in the openings 9, 10 is avoided.

The flat element 7 is made of a material with good thermal conductivity, such as aluminium, to enable it to efficiently lead the cold temperature to the side on which the ice is to freeze. On top of the flat element 7 is arranged at least one pair of Peltier elements 11 , 12. These utilise the so-called thermo-electric effect, also known as the Seebeck effect, for generating cold. This effect arises when two different conductive metals are combined to form one pair of elements. By connecting together two pairs of elements and applying an electric current the two elements will attain different temperatures. The cold side of the elements is arranged facing the flat element 7 and the warm side is turned away from the flat element 7. The cold side leads the cold into the flat element 7, which freezes the water that is applied to the flat element 7.

A large amount of heat is generated during the refrigeration process. Thanks to the warm sides of the Peltier elements being turned away from the flat element, heat will rise and be led away through fins 15 and a fan (not shown) arranged in direct conjunction with the Peltier elements 11 , 12. The size of the fin 15 is adapted to the size of the Peltier element 11 , 12. On the embodiment described herein, a planed fin 15 is used with a number of thin fins. This provides a large surface area in contact with the surrounding air in relation to the bottom area and thereby good heat transfer properties.

Once the ice has frozen to the desired thickness, it will come loose from the bottom 8 of the flat element 7. This is done by cutting the power to the Peltier elements 11 ,

12 and the fan, thereby leading the heat that has been diverted by the fins 15 and the fan to the flat element 7 for heating it up instead. Consequently, the ice surface facing the bottom 8 of the flat element 7 is warmed up and the cake of ice comes loose. In another embodiment, the operation of the Peltier elements 11 , 12 is reversed to produce heat instead of cold to achieve the same effect. As soon as the cake of ice is loosened, the freezing process is restarted.

Once the cake of ice loosens, it falls onto a grille of taut, essentially horizontal wires 13 of Kanthal, for example, arranged to a frame 14 in the upper part of the box below the flat element 7. The wires 13 are oriented so that they cut the formed cake of ice both lengthwise and crosswise and are suspended at different levels in the frame construction 14 by means of metal clips of spring steel. This is so that the wires 13 attain the same tension even after long periods of use and to avoid the crossed wires 13 from making contact with each other. The wires 13 are heated through a connection to the source that powers the Peltier elements 11 , 12 and is insulated from the frame 14 with pieces of plastic between the clips and the frame 14. When the ice lands on the wires 13, the heat in the wires 13 cuts through the cake of ice to form individual pieces of ice, primarily in the form of cubes. These fall down into a storage compartment 16 arranged between the wires 13 and the water tank 4. Other ice shapes are possible to produce depending on the way the wires 13 are suspended.

The said flat elements 7 can well be inclined somewhat in relation to the horizontal axis. This incline is used to release the cake of ice in a controlled manner onto the grille 13. If the flat element 7 is completely horizontal, the cake could come loose at any point, which could mean that the cake tips over and lands on its end on the grille. Thanks to the incline of the flat element 7, this can be avoided as the cake will always fall onto the grille

13 in the correct manner. It should be understood that despite the aforesaid advantages with the incline of the flat element, it can also be situated completely horizontally.

The storage space 16 comprises a drawer in which the finished ice cubes are kept and can also be used to fill new water. The temperature inside the drawer is close to freezing point and is cooled by the Peltier elements 11 , 12. As the temperature is close to freezing point, the ice will not melt but the cubes will still not freeze to each other. Each time the drawer is pulled out, however, the space will warm up and the ice cubes can melt somewhat. The filled water and said meltwater will run to the tank 4 through holes 17 arranged in the drawer and pass through a hose (not shown) to the said pump.

The device is intended to be powered from a 12, 24 or 220 volt source and the entire process is controlled by an electronic unit comprising the different components' on/off switches and a unit for transforming the voltage to a suitable level. When starting the device, the pump is turned on at the same time as the Peltier elements 11 , 12 start to generate cold. In the box 2 storage space 16 is arranged a temperature sensor connected to the electronic unit for regulating the temperature in the storage space 16. The process is continuous and automatic, where the temperature of the flat element 7 controls the pump flow and the intervals at which the water is applied to the flat element 7, and the water level in the tank 4 controls the cut-out or reversing of the Peltier elements 11 , 12 and switching off the pump. The grille with heating conductor wires 13 is activated for a period that is determined by the electronic unit after the Peltier elements 11 , 12 have been turned off or reversed and deactivated at the same time as the Peltier elements 11 , 12 start to generate cold again. In case the water in the tank 4 runs out, the pump and the Peltier elements 11 , 12 will be turned off, whereby the cake of ice that has formed will come loose and fall onto the heater wires 13, which will be activated at the same time. Furthermore, the device is adapted to a cleaning position where the pump is running even when the Peltier elements 11 , 12 are turned off.

The present invention is not limited to the above description and as illustrated in the drawings but can be changed and modified in a number of different ways within the framework of the idea of invention specified in the following claims.

Claims

1. Device for producing ice cubes comprising an arrangement (5, 6, 9, 10) and a pump for supplying a fluid to a body (7) with a first and a second side, which body (7) on its first side is fitted at least one Peltier element (11 , 12) for thermo-electric refrigeration of the body (7), c h a r a c t e r i s e d in that the fluid supplying arrangement (5, 6, 9, 10) and the body (7) are so arranged relative to each other that the fluid is dispersed to the second side of the body (7).

2. Device according to claim 1 , whereby the body (7) comprises a flat element oriented essentially parallel to the horizontal axis.

3. Device according to claim 1 , whereby the body (7) comprises a flat element oriented somewhat at an angle to the horizontal axis.

4. Device according to any one of the previous claims, whereby the fluid is supplied to the downward-facing side (8) of the body (7).

5. Device according to any one of the previous claims, whereby the fluid is supplied under pressure.

6. Device according to any one of the previous claims, whereby the body (7) comprises a material with good thermal conductivity.

7. Device according to any one of the previous claims, whereby the fluid supplying arrangement comprises at least one nozzle (5, 6) with an opening (9, 10).

8. Device according to claim 7, where by the size of the nozzle (5, 6) opening

(9, 10) in relation to the pump pressure is chosen so that the water is supplied in dispersed form.

9. Device according to any one of the previous claims, whereby it comprises a fan and cooling fins (15) arranged on the upward-facing side (8) of the body (7).

10. Device according to any one of the previous claims, whereby the supplied fluid forms a block of ice on the bottom (8) of the body (7).

11. Device according to any one of the previous claims, whereby the formed block of ice is removed/freed by reversing the operation of the Peltier element (11 ).

12. Device according to any one of the previous claims, whereby the formed block of ice is loosened by cutting the power to the Peltier element (11) and fan.

13. Device according to any one of the previous claims, whereby it comprises electrically conducting wires (13) forming a grille under the body (7) for dividing up the block of ice into ice cubes.

14. Device according to any one of the previous claims, whereby the wires (13) are arranged at separate levels from each other.

15. Device according to any one of the previous claims, whereby the fluid comprises water.

16. Device according to any one of the previous claims, whereby it comprises a storage box (16) for collecting the formed ice cubes.

17. Device according to claim 15, whereby the storage box (16) has an opening for filling with fluid and a drain hole (17) in the bottom for returning the fluid to the pump.