JP2002122376A - Household cold storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water coupling material which is frozen in a short time in a household refrigerator and makes its frozen state confirmable and a cryogen which can be used for a longer time. SOLUTION: A household cold storage system uses 1.8-4 mol wt.% potassium chloride solution in a state where the upper half of the liquid is transparent and a polyethylene container having a thickness of <=2 mm and a volume of <=1 liter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a domestic cool storage system.

[0002]

2. Description of the Related Art Since home freezers are widely used, freezing agents frozen in home freezers are extremely important. However, none of the conventional regenerators has a surface temperature of −10 ° C. or lower and freezes in a home freezer in a short time. For example, Japanese Patent Publication No. 7-47731 states that an ammonium chloride solution is completely frozen in a household freezer.
However, they may or may not actually freeze. This is because the average temperature of small home freezers is around -16 ° C, so that the ammonium chloride solution is hard to freeze in some containers.

[0003] In the case of a large freezer, -21 ° C (JIS
However, it does not freeze in a short time because the door is actually opened and closed, and other items are blocked and convection deteriorates. According to the inventor's experiments, the upper temperature rises to -10 ° C once the door is opened and closed. However, since the refrigerator did not operate immediately, it was found that even in a large freezer, the ammonium chloride solution could not be frozen in one day.

[0004] As described above, in a home freezer, the surface temperature is -1.
It is important to obtain a regenerator at 0 ° C. or lower, but it has been difficult to specify the conditions.

[0005]

The fact that the regenerator can be used at home freezer temperature (the lower limit is determined by Japanese Industrial Standard so that the lower limit is designed to be -21 ° C.) can be said to be an extremely important industrial issue. Therefore, a regenerator having a surface temperature of −10 ° C. or lower that can be reliably frozen in a home freezer is provided, and freezing can be confirmed. In addition, among the potassium chloride regenerators, those that are effective for a longer time are provided, and a regenerator system using a home freezer is constructed.

[0006]

Means for Solving the Problems The inventor of the present invention has found that, as a condition of a regenerator having a temperature of -10 ° C. or less, which is frozen in a domestic freezer within 24 hours, a 1.8 to 4 mol% potassium chloride aqueous solution is the only condition. Was found to belong to It was found that combining this with a home freezer could be a useful cold storage system.

It has also been found that a 1.8 to 4 mol% potassium chloride solution has a long-term holding power. A variety of cold storage containers are conceivable, but the condition of the container is that the container is made of polyethylene and has a thickness of 2 mm or less and a volume of 1 liter or less.

However, it has been found that when these frozen bodies are partially unfrozen, they have high melting rates and cannot be effective cold storage bodies for a long time. As described above, there is a problem in the refrigerating capacity of a home freezer, and it can be said that it is extremely important to know whether or not the freezer is frozen. The present invention has solved this problem by using a transparent container. When the frozen body is a constant-temperature frozen body, it becomes a white frozen body and it can be visually confirmed whether or not it has completely frozen. Therefore, a combination of a transparent container and a thermostated frozen body is a requirement. The constant temperature frozen matter is a completely frozen and whitened solid, which has a latent heat of melting. In the present invention, a potassium chloride solution corresponds to this.

First, the means will be described. The transparent container or bag referred to in the present invention does not need to be entirely transparent, but it is necessary that at least half of the transparent container or bag is transparent. This is because at least one side must be transparent in order to tell whether it is completely frozen. The transparency may be such that the inside can be frozen, and includes a translucent one. For example, polyethylene (a translucent high-medium density material having a thickness of less than 2 mm) is applicable. Colored containers that are difficult to see inside, those that have printed labels adhered to most of them, those that are printed on most of the containers, etc. do not correspond to transparent surfaces. In these, at least one other side must be transparent. The condition for confirming that all the components are frozen is that, in the case of a container having six surfaces, if the widest surface is placed on the upper and lower sides, most of the upper and lower surfaces including at least one center must be transparent or translucent. Also, in the upright state, that is, when the side face is up and down, the upper part is hard to freeze, so at least one of the side faces must be transparent.

As a material having good thermal conductivity (unit: W / m.K), polyethylene (0.
4), nylon (0.25), polypropylene (0.2
4) and the like, but even under the same other conditions, a phenomenon was observed in which the polyethylene container was frozen in a polyethylene container having a thickness of 2 mm but not frozen in polypropylene. From the above, it is necessary to be made of polyethylene and have a thickness of 2 mm and a volume of 1 liter or less.
Among polyethylene, high, medium, low density polyethylene, and crosslinked polyethylene have good thermal conductivity, and any of them can be used in the present invention.

An aqueous potassium chloride solution of less than 12% has a short melting time and does not reach a temperature of -10 ° C., so that it cannot be used as an effective freezing agent for a long time. Therefore, a useful regenerator must be 12-25% by weight (1.8-4% by weight) liquid.

[0012]

Example 1 A polyethylene-nylon laminate bag (transparent) having a thickness of 0.15 mm was charged with 750 ml of a 12, 15, or 20% by weight potassium chloride solution, and frozen in a National household freezer (-21 ° C) (complete whitening was performed). 20% (surface temperature -13 ° C) when left at room temperature.
Takes the longest time to melt, followed by 15% (-11 ° C), and the 12% (-10 ° C) retention time is 20%, 2%.
/ 3. When the concentration was lower than that, the surface temperature was high and the holding time was too short to be practical.

[0013]

[Embodiment 2] 20 mm x 14 mm x 2.5 c with 1.5 mm thickness
In a polyethylene container of 600 m, 600 ml of an 18% by weight potassium chloride solution was placed and left in a Sharp household freezer. It was completely frozen after 12 hours. Next, the thickness 1.8m
A polyethylene container measuring 27 × 18 × 2.5 cm and containing 1,150 ml of the same liquid was completely frozen after 20 hours.

Claims (5)

[Claims] 1. A cold storage system in which a cold storage unit containing a potassium chloride solution having a concentration of 12 to 25% by weight in a container and a freezer designed to have a lower limit temperature of -21 ° C. are combined. 2. The cold storage system according to claim 1, wherein the storage body is made of polyethylene and has a thickness of 2 mm or less and a volume of 1 liter or less. 3. The regenerative storage system according to claim 1, wherein the storage body includes a visual confirmation unit for visually confirming that the whole body has turned white due to freezing. 4. The visual checking means is configured to select one of the following: the storage body is transparent; the storage body is translucent; or a part of the storage body is transparent or translucent. 4. The cold storage system according to claim 3, wherein: 5. A method for obtaining a completely frozen regenerator using the regenerative system according to claim 1, 2, 3, or 4.