JP2004003754A - Ice making apparatus and refrigerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the following problems: bubbles are confined without leaving an interface between ice and water, need for a large-scale apparatus causes a significant cost increase, and need for ice making inside a container in a home refrigerator or a business refrigerator makes it difficult to produce ice pillars. <P>SOLUTION: In this ice making apparatus, an ice making chamber 1 is provided under a refrigerating chamber 7 provided with a water supply tank 6, the ice making chamber 1 is partitioned by a cooling board 2 to form two spaces 16, 17. An upper space is defined as a refrigerating space 17 and a lower space is defined as a freezing space 16, and an ice making container 3 is disposed on the cooling board 2 to intermittently supply water to an opening portion in the ice making container 3 for ice making. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to an ice making device and a refrigerator for making transparent ice in a home refrigerator.
[0002]
[Prior art]
Conventionally, transparent ice in home refrigerators is supplied by supplying water to an ice tray and then vibrating the ice tray to prevent air bubbles generated due to freezing from entering the ice or to remove air or the like before making ice. A method of making ice using degassed dissolved gas has been adopted. Further, after water was supplied, the upper portion of the ice tray was heated to provide a temperature difference between the upper and lower portions of the ice tray, thereby preventing bubbles generated during freezing from being mixed into the ice. Also, in commercial ice-making machines, a method has been adopted in which an ice tray for freezing water is downwardly supplied in a fountain shape, and the ice is gradually frozen from the side of the ice tray. Further, there has been a method of growing single crystal ice following natural ice bamboo shoots.
[0003]
[Problems to be solved by the invention]
As described above, a major problem in making transparent ice is how to prevent air bubbles generated during freezing from being taken into the ice. Another object of the present invention is to prevent precipitation of hardness ion components present in well water or mineral water having high hardness, and to prevent bubbles generated by the hardness ion components as nuclei.
[0004]
Generally, tap water contains about 15 to 30 ppm of a hardness ion component and about 20 ppm of a dissolved gas. When water crystallizes into ice, it becomes transparent ice or opaque ice depending on the balance between the rate at which water crystallizes and the rate at which impurities are discharged from the crystallized ice. In particular, the formation of opaque ice by the dissolved air greatly depends on the diffusion of air in the water, and when the interface movement speed of the ice and water is high, the dissolved air is trapped in the ice.
[0005]
However, when the interface movement speed is low, air molecules that cannot enter ice accumulate in water near the interface, and a region with an excessive air molecule concentration is formed. The number of molecules of such excess air gradually increases as the ice grows, and when a certain limit is exceeded, macroscopic air bubbles are formed and finally trapped in the ice that has progressed. A method of physically vibrating an ice tray to prevent bubbles generated when water crystallizes from being trapped in ice is somewhat transparent, but if the generated bubbles are small, There is a problem that bubbles are not separated from the interface between ice and water and are trapped in the ice.
[0006]
In addition, a method of removing gas components by degassing before crystallization is effective in producing transparent ice.However, this method not only leads to a large-scale apparatus, leading to a significant increase in cost, but also requires time for ice making. However, air melts again into the degassed water, and bubbles are generated during crystallization, so that there is a problem that ice with high transparency cannot be obtained.
[0007]
Furthermore, there is a method of making single crystal ice with high transparency by dropping water droplets on a flat part without a container, but it is necessary to make ice in a container in a home refrigerator or a commercial freezer, like an ice bamboo shoot. There was an issue that had to be done.
[0008]
SUMMARY OF THE INVENTION An object of the present invention is to provide an ice making device and the like capable of making ice with high transparency in a relatively short time in consideration of such a problem of the conventional ice making device.
[0009]
[Means for Solving the Problems]
A first aspect of the present invention is that a space A held at a temperature higher than 0 ° C. is separated by a cooling plate and is adjacent to a space B held at a temperature lower than 0 ° C.
A water supply nozzle for supplying water to the ice making container on the cooling plate is disposed in the space A,
An ice making device for making ice by intermittently supplying water to the ice making container.
[0010]
According to a second aspect of the present invention, there is provided a refrigerator including the ice making device according to the first aspect of the present invention and a refrigerator.
The refrigerator compartment is arranged on the space A,
The ice making container and the water supply nozzle are arranged in a metal container,
A refrigerator provided with a window in a region that partitions the space A and the refrigerator so that the temperature outside the metal container becomes the temperature of the refrigerator.
[0011]
A third invention is a refrigerator including the ice making device according to the first invention and a refrigerator.
Temperature detection means at the bottom and top of the ice making container,
When the bottom temperature of the ice making container became lower than a predetermined temperature, the intermittent water supply was started, water supply was stopped after water was supplied for a predetermined time, and the top temperature of the ice making container became lower than the predetermined temperature. And a control means for starting ice separation.
[0012]
A fourth aspect of the present invention is the refrigerator according to the second aspect of the present invention, wherein a water supply tank is disposed in the refrigerator compartment, and the water is supplied by a water supply pump.
[0013]
According to a fifth aspect of the present invention, a water supply tank is disposed in the refrigerator compartment,
Further, a vacuum pump for sucking air in the metal container is provided,
An electromagnetic valve is provided at a predetermined position between the water supply tank and the water supply nozzle,
A refrigerator according to a second aspect of the present invention in which ice is produced by intermittently supplying water into the ice making container by turning on and off the electromagnetic valve.
[0014]
In a sixth aspect of the present invention, the cooling plate is openable and closable,
Temperature detection means is provided at the bottom and the top of the ice making container,
Having an opening and closing detection means for detecting an opening and closing operation by the cooling plate,
By the control means, when the cooling plate is closed, the electromagnetic valve is closed to start evacuation, and when the temperature of the bottom of the ice making container becomes lower than a predetermined temperature, the electromagnetic valve is closed. Water is supplied by turning on for a predetermined period of time, intermittently supplying water by repeating turning off after a predetermined period of time and stopping water supply, stopping water supply after supplying water for a predetermined time, the temperature of the upper part of the ice making container is lower than a predetermined temperature. A refrigerator according to a fifth aspect of the present invention, wherein the evacuation is stopped when the temperature of the refrigerator also becomes low, and ice separation is started.
[0015]
A seventh aspect of the present invention is the refrigerator according to any one of the second to sixth aspects of the present invention, wherein the space A and the space B are each provided with an outlet for cool air.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention will be described below with reference to the drawings.
[0017]
(Embodiment 1)
FIG. 1 shows an ice making apparatus for making transparent ice. The ice making room 1 is provided with a space B (hereinafter, referred to as a freezing space 16) maintained at a temperature lower than 0 ° C. via a partition including the heat insulating material 11, a packing 9 for closing a window provided in the partition, and the cooling plate 2. And a space A maintained at a temperature higher than 0 ° C. (hereinafter referred to as a refrigerated space 17).
[0018]
One of the major differences from the conventional ice making is that the ice making is performed not in the freezing space 16 but in the refrigerated space 17 and the frozen space 16 is used to store the ice made ice. For example, an ice-making container made of PP (polypropylene) (hereinafter referred to as an ice-making tray 3) is disposed on the cooling plate 2, and thus is located on the refrigeration space 17 side. The cooling plate 2 uses a metal having good heat conductivity, such as Al or Cu.
[0019]
Further, as shown in FIG. 2, the refrigerator compartment 7 is disposed adjacent to the ice making compartment 1, and water for water supply is put in a water supply tank 6 installed in the refrigerator compartment 7 and cooled in advance. In advance, water is supplied intermittently from the water supply nozzle 5 to the ice tray 3 via a water supply pump 13 (for example, a gear pump or a piezoelectric pump).
[0020]
The ice tray 3 and the water supply nozzle 5 are arranged in a metal container 14 made of, for example, Al, and are connected to the refrigerated space 17 of the ice maker 1 such that the metal container 14 has the same temperature (> 5 ° C.) as the refrigerator 7 The refrigerating room 7 communicates with the ventilation holes 12 so that the refrigerating space 17 can always be maintained at a higher temperature than the freezing space 16. Here, the reason why the ice tray 3 and the water supply nozzle 5 are arranged in the metal container 14 is to prevent the smell of the food placed in the refrigerator compartment 7 from entering the ice and giving an unpleasant smell. .
[0021]
With this arrangement, the bottom surface of the ice tray 3 is below the freezing point and the upper portion has a temperature of 2 to 3 ° C., so that a temperature difference occurs between the bottom surface and the upper portion, and the ice tray 3 gradually freezes from the bottom surface.
[0022]
For example, thermistors 19 and 20 are installed at the bottom and the top of the ice tray 3 as temperature detecting means, respectively, and when the temperature of the thermistor 19 installed at the bottom of the ice tray 3 becomes lower than -18 ° C., a water supply pump is provided. 13 is operated to supply water intermittently. For example, the water supply amount is set to 0.2 ml each time, and the water supply is stopped for one hour and 45 minutes at two-minute intervals to stop the water supply (control means is not shown). When the temperature of the thermistor 20 becomes −5 ° C. or less, the actuator 10 is operated to perform ice release.
[0023]
Here, a description has been given using a thermistor as the temperature detecting means, but a thermocouple such as chromel alumel may be used. When 0.2 ml of water freezes from the bottom surface, the latent heat is released, and the temperature of the thermistor 19 is detected to rise slightly. Small bubbles are generated in the air.
[0024]
When all of the supplied water freezes, the generated bubbles are trapped in the ice and cause turbidity.However, the next water supply starts with a little water remaining, so the generated bubbles are trapped in the ice. Spreads into the water supplied without being trapped in the water and begins to freeze again. By repeating this in sequence, transparent ice free of bubbles can be made. In addition, tap water having a hardness of about 50 contains a hardness ion component or dissolved silica serving as a nucleus of a bubble, but before the bubble is formed, the next water supply is started. Slightly contained in the ice, most of it comes out of the ice and adheres to the ice surface and ice trays without losing the transparency of the ice.
[0025]
In addition, since the water supply tank, water supply pump, and water supply nozzle are all located in the refrigerated space where the temperature is maintained at a temperature higher than 0 ° C, there is no need for a heater or the like to prevent freezing, and the ice making room set by the refrigerator -20 ° C and refrigeration room 5 ° C can be used as they are.
[0026]
In the above description, the ventilation holes 12 are provided so that the temperature of the refrigerated space 17 becomes equal to the temperature of the refrigerated room 7. However, as shown in FIG. The metal container 14 for preventing the odor of the refrigerator compartment 7 is unnecessary, and the structure is simplified.
[0027]
(Embodiment 2)
Next, a second embodiment for making transparent ice will be described in detail with reference to FIG. The difference from the first embodiment is that an electromagnetic valve 31 is used in place of the water supply pump 13 and the vacuum pump 32 for reducing the pressure in the metal container 14 to deaerate the supplied water is a metal pump. That is, it is connected to the container 14.
[0028]
The load on the vacuum pump 32 is reduced by making the volume of the metal container 14 as small as possible. It is known from Henry's law that the concentration of a dissolved gas dissolved in water is proportional to the concentration in the gas phase. Therefore, by lowering the concentration of air in the gas phase, the concentration of dissolved gas dissolved in water can be reduced, and the generation of bubbles during freezing can be suppressed. However, what should be noted here is that since the vapor pressure of water at 0 ° C. is 4.58 mmHg, if the degree of vacuum is higher than this, the supplied water will not evaporate. Therefore, by using a pressure in the metal container 14 in the range of 0.1 atm, that is, 76 mmHg to 0.01 atm, that is, 7.6 mmHg, the dissolved gas in the water can be degassed while suppressing water evaporation, and the vacuum The load on the pump 32 can also be reduced.
[0029]
By opening the electromagnetic valve 31 in the ice tray 3 composed of eight cells, water can be supplied to the ice tray 3 by the pressure difference between the water supply tank 6 and the inside of the metal container 14. 0.6 ml of water will be supplied. As described above, the turbidity of ice is mainly caused by dissolved air dissolved in water. Therefore, if the concentration of dissolved air is reduced to 1/10 to 1/100, the concentration of dissolved air in the ice depends on the concentration of dissolved air. The amount of air bubbles taken into the glass decreases, and the transparency increases.
[0030]
In this embodiment, when one cell is considered, degassing starts from the moment 0.2 ml of water enters the metal container 14, water is supplied to the ice tray 3, and freezing starts when the freezing temperature is reached. However, the next water supply is started with almost no bubbles generated. Even when tap water with a hardness of 50 is used, the hardness ion component or dissolved silica that serves as the nucleus of air bubbles is contained, but the next water supply starts without generation of air bubbles and does not become the nucleus of air bubble generation. The hardness ion component and the dissolved silica are slightly contained in the ice, and most of them are outside the ice and adhere to the surface of the ice or the surface of the ice tray, so that the transparency of the ice is not impaired. When PP is used for the ice tray 3, 10 ml of water can obtain transparent ice having a transparency close to 100% in about 2 hours. When a metal such as Al is used, 10 ml of water can obtain 90% transparency in about 1 hour. % Clear ice was obtained. Further, since the water supply tank 6, the solenoid valve 31 and the water supply nozzle 5 are all located in the refrigerated space where the temperature is kept higher than 0 ° C., a heater or the like for preventing freezing is not required, and it is set in the refrigerator. The temperature in the ice making room is -20 ° C, and the temperature in the refrigerator room is 5 ° C.
[0031]
In this embodiment, it is needless to say that the same operation as in the first embodiment can be performed by installing thermistors (not shown) as temperature detecting means at the bottom and the top of the ice tray 3, respectively.
[0032]
Also in the present embodiment, as shown in FIG. 5, it is possible to install the outlet 51 in the refrigerated space 17 without providing the refrigerated space 17 and the ventilation holes 12 in the refrigerated room 7. Since vacuum evacuation is required, the metal container 14 is necessary, and the simplification is not performed as in the first embodiment. However, since the temperature of the refrigerated space 17 can be independently controlled, it is possible to make ice with extremely high transparency.
[0033]
【The invention's effect】
As described above, according to the present invention, the following effects can be obtained.
[0034]
By intermittently supplying water to the ice making container instead of collecting ice in a conventional ice making container, it became possible to make ice with high transparency in a relatively short time.
[0035]
In addition, since ice is made while deaeration of the supplied water, very transparent ice can be made without any air bubbles, which is a main cause of cloudiness, and the transparency is always 90% or more even in a short time. Ice making is now possible.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an ice making device showing one embodiment of the present invention. FIG. 2 is a front view of a refrigerator showing one embodiment of the present invention. FIG. 3 is an ice making device showing one embodiment of the present invention. FIG. 4 is a cross-sectional view of an ice making device showing one embodiment of the present invention. FIG. 5 is a cross-sectional view of an ice making device showing one embodiment of the present invention.
DESCRIPTION OF SYMBOLS 1 Ice making room 2 Cooling plate 3 Ice making tray 5 Water supply nozzle 6 Water supply tank 7 Refrigeration room 8 Ice storage 9 Packing 11 Insulation material 12 Vent hole 13 Water supply pump 14 Metal containers 19 and 20 Thermistor 31 Solenoid valve 32 Vacuum pump

Claims (7)

A space A held at a temperature higher than 0 ° C. is adjacent to a space B held at a temperature lower than 0 ° C., separated by a cooling plate,
A water supply nozzle for supplying water to the ice making container on the cooling plate is disposed in the space A,
An ice making device for making ice by intermittently supplying water into the ice making container. A refrigerator comprising the ice making device according to claim 1 and a refrigerator compartment,
The refrigerator compartment is arranged on the space A,
The ice making container and the water supply nozzle are arranged in a metal container,
A refrigerator provided with a window in a region separating the space A and the refrigerator so that the temperature outside the metal container becomes the temperature of the refrigerator. A refrigerator comprising the ice making device according to claim 1 and a refrigerator compartment,
Temperature detection means at the bottom and top of the ice making container,
When the bottom temperature of the ice making container became lower than a predetermined temperature, the intermittent water supply was started, water supply was stopped after water was supplied for a predetermined time, and the top temperature of the ice making container became lower than the predetermined temperature. Refrigerator provided with control means for starting ice release at the time. The refrigerator according to claim 2, wherein a water supply tank is disposed in the refrigerator compartment, and the water supply is performed by a water supply pump. A water tank is arranged in the refrigerator compartment,
Further, a vacuum pump for sucking air in the metal container is provided,
An electromagnetic valve is provided at a predetermined position between the water supply tank and the water supply nozzle,
3. The refrigerator according to claim 2, wherein the ice is made by intermittently supplying water into the ice making container by turning on and off the electromagnetic valve. The cooling plate is openable and closable,
Temperature detection means is provided at the bottom and the top of the ice making container,
Having an opening and closing detection means for detecting an opening and closing operation by the cooling plate,
By the control means, when the cooling plate is closed, the electromagnetic valve is closed to start evacuation, and when the temperature of the bottom of the ice making container becomes lower than a predetermined temperature, the electromagnetic valve is closed. Water is supplied by turning on for a predetermined period of time, intermittently supplying water by repeating turning off after a predetermined period of time and stopping water supply, stopping water supply after supplying water for a predetermined time, the temperature of the upper part of the ice making container is lower than a predetermined temperature. 6. The refrigerator according to claim 5, wherein the evacuation is stopped when the temperature of the refrigerator also becomes low, and ice removal is started. The refrigerator according to any one of claims 2 to 6, wherein each of the space (A) and the space (B) is provided with a cool air outlet.

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