JPH0452630Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field This invention relates to an improved structure of a freezer that uses the metal inner box itself as a cooler and cools the internal storage chamber to an extremely low temperature such as -80°C. It is.

(b) Prior Art A conventional freezer of this kind is disclosed in, for example, Japanese Utility Model Publication No. 13257/1983. In other words, this type of freezer has a storage chamber that opens upward inside the inner box, and is configured to keep the inside of the storage chamber at an extremely low temperature such as -80℃ using a binary refrigeration cycle or a mixed refrigerant cycle. Since the inner box is at a low temperature, it is made of a heat conductive metal such as stainless steel in consideration of its strength, and the cooling pipe of the refrigeration cycle is wound around the outer surface of this inner box.

On the other hand, with the recent spread of frozen foods and frozen desserts, shops are increasingly using dry ice. Since it was only stored in a vacuum, there was a large loss due to sublimation of dry ice (approximately 5% per day), making it uneconomical. Therefore, in recent years, it has been considered to suppress loss due to sublimation by storing dry ice in the above-mentioned freezer at a temperature below -78°C (atmospheric pressure), which is the sublimation temperature of dry ice.

(c) Problems that the invention aims to solve By the way, even if the temperature of dry ice itself drops below -78℃, the difference between the partial pressure of carbon dioxide on the surface of the dry ice and the partial pressure of carbon dioxide in the atmosphere around the dry ice Sublimation occurs proportionally, and even if it is stored at a low temperature, the amount will simply decrease, and even if it is stored in the freezer as mentioned above, sublimation will gradually occur as it passes through the kraft paper. . Therefore, since this sublimated carbon dioxide is heavier than air, the concentration of carbon dioxide gas in the storage chamber becomes high. Then, as shown in FIG. 4, the dry ice recondenses as dry ice along the inner surface of the cooling pipe section of the inner box where the temperature is lowest and becomes crystals. In FIG. 4, 5 is a stainless steel inner box, 6 is a storage chamber inside the inner box 5, and 7 is a cooling pipe wound around and fixed to the heat insulating material 8 side of the inner box 5.
In addition, 9 is recrystallized dry ice, which grows in large quantities in the cooling pipe 7 section where the temperature is the lowest, and in the storage chamber 6.
It has a shape that protrudes greatly to the side.

When such recrystallization occurs, the crystals 9 reach the stored dry ice and combine with it, and must be forcibly destroyed in order to be taken out. There was a problem with lowering the partial pressure of carbon dioxide within the reactor, which encouraged further sublimation.

The present invention has been made to solve these problems.

(d) Means for solving the problem The present invention uses the metal inner box itself that constitutes the storage chamber that opens upward as a cooler, and the inside of the storage chamber of the freezer that cools the storage chamber to an extremely low temperature has a sliding surface on the surface. have sex,
A bag member is provided, which is molded from a carbon dioxide gas-impermeable synthetic resin and has a shape that follows the shape of the inner peripheral surface of the inner box. Further, if necessary, the bag member is provided with a flap, and a frame member for pressing the upper part of the bag member is provided on a stepped portion formed at the edge of the opening of the storage chamber.

(e) Effect According to the present invention, when dry ice is stored, the presence of the bag member prevents sublimated carbon dioxide from directly recondensing on the inner box surface. In addition, since the bag member is made of synthetic resin, which is a poorer thermal conductor than metal, large amounts of local recrystallization do not occur, unlike metal inner boxes.
Since it has surface smoothness, recrystallization can be easily removed. Furthermore, the bag member can be easily attached and removed, and if a flap is provided, the partial pressure of carbon dioxide around the dry ice will increase. Furthermore, if the bag member is held down by the frame material, it will not fall to the bottom of the storage room due to its flexibility.

(F) Embodiments Next, embodiments of the present invention will be explained with reference to the drawings.
FIG. 1 is a longitudinal sectional view of the freezer 1 of the present invention, FIG. 2 is a diagram showing the procedure for attaching the bag member 2, and FIG. 3 is a perspective view of the freezer 1 excluding the bag member 2. Note that the same reference numerals as in FIG. 4 are the same. An upwardly opening stainless steel inner box 5 is installed with a gap in an upwardly opening steel plate outer box 3, and the upper ends thereof are connected to each other by a breaker 4.
A foamed heat insulating material 8 such as polyurethane foam is filled between the two boxes 3 and 5 to form a main body 9. A cooling pipe 7 of a cooling device (not shown) is wound around the inner box 5 and fixed to the surface (outer surface) of the inner box 5 on the side of the heat insulating material 8 (outer surface) with aluminum tape or the like for heat exchange.
10 is a machine room formed on the side of the main body 9 and houses the aforementioned cooling device, control circuit, etc.; 11 has a gasket 12 on the inner periphery; It is an insulated door that is pivotally supported. In addition, 14 is the stepped portion 1 of the breaker 4.
This is an inner lid made of styrofoam placed on 5.

The bag member 2 is made of a synthetic resin sheet (about 0.1 mm thick) that has a slippery surface and is impermeable to carbon dioxide gas, such as polyethylene, and is made by welding each side of the sheet. It is formed into a box shape with an upward opening that follows the shape of the inner peripheral surface of the inner box 5. Furthermore, the bag member 2 has flaps 2a extending from each side of the upper end of the box-shaped portion. Further, numeral 17 is a rectangular frame-shaped frame material molded from vinyl chloride, and has a size that allows it to be placed on the stepped portion 15 of the breaker 14.
The bag member 2 is inserted into the inner box 5 before the cooling device starts operating, and each corresponding surface is opposed to the inner surface of the inner box 5. This makes it possible to use the internal volume of the storage chamber 6 effectively, and since only a single bag member 2 is inserted, the assembly work is much easier than when each side is separate. It's easy. The reason why it is inserted before the cooling operation is that if it is inserted after the cooling operation, the cold air in the storage chamber 6 that has been cooled once will be discharged by the insertion. Next, the flap 2a is expanded, and the frame member 17 is placed on the stepped portion 15 from above to hold down the base of the flap 2a, and the bag member 2 falls to the bottom of the storage chamber 6 due to its flexibility. prevent After that, when the flap 2a is turned inward and the cooling device starts operating, the inner box 5 is first cooled by the cooling pipe 7, and then the bag member 2 is cooled by the cooling from the inner box 5, and the storage chamber 6 is cooled. Inside is bag member 2
The heat insulating door 11 is gradually cooled down until it reaches a predetermined temperature, for example -80℃
etc., expand flap 2a and add dry ice D.
is stored, and the flap 2a is folded down again to cover the top surface of the dry ice D and stored. This state is the state shown in FIG.

At this time, although a small amount of sublimation occurs from the surface of the dry ice D, the bag member 2 prevents the carbon dioxide gas from reaching the inner surface of the inner box 5, so dry ice remains on the inner surface of the inner box 5 as shown in FIG. This prevents recrystallization. On the other hand, since the bag member 2 is made of synthetic resin, it is a poorer thermal conductor than metal, so the temperature of the inner surface of the bag member 2 is somewhat higher than that of the inner box 5, and especially the part where the cooling pipe 7 is present, such as the inner box 5. There is no decrease, and the temperature is almost uniformly lower than the sublimation temperature of dry ice D as a whole, so the bag member 2
Even if dry ice were to recrystallize on the inner surface, the amount would be small and would be uniform. or,
Since the dry ice D is substantially sealed by the flap 2a, the partial pressure of carbon dioxide within the bag member 2 becomes extremely high, and sublimation on the surface of the dry ice D is significantly reduced. Therefore, in combination with storage at extremely low temperatures, the amount of loss due to sublimation can be significantly reduced, and the dry ice is stored with the re-condensed dry ice growing and overhanging toward the storage chamber 6. It does not combine with D and become difficult to take out. Furthermore, since the bag member 2 is a single unit, it can be easily removed from the storage chamber 6 to remove dry ice that has re-condensed on the surface, and can be easily scraped off since it has a slippery surface. It can be dropped. Further, in order to prevent damage to the bag member 2 due to collision with the dry ice D, a cushioning material may be placed at the bottom of the storage chamber 6 as necessary.

(g) Effects of the invention According to the invention, when storing dry ice, carbon dioxide sublimated from the stored dry ice is prevented from recondensing on the inner surface of the inner box. In addition, there are fewer crystals that condense on the inner surface of the synthetic resin bag member,
In addition, since it is generated uniformly, a large amount of recrystallization does not grow locally toward the storage chamber, as it does when it grows on the inner box, and it combines with the stored dry ice and becomes difficult to remove. It also disappears. In addition, since the bag member is shaped to follow the inner surface shape of the inner box, the internal volume of the storage chamber can be used effectively, and since it is a single unit, it is easy to deliver it to the storage chamber, and the bag has a smooth surface. This has great practical effects, such as easy removal of crystals.

Furthermore, the stored dry ice can be substantially sealed by the flap, thereby maintaining a high partial pressure of carbon dioxide within the bag member, thereby reducing recondensation and significantly reducing loss due to sublimation. .

Furthermore, by pressing the bag member with the frame material, it is possible to prevent the bag member from falling to the bottom of the storage chamber due to its flexibility or by storing dry ice.

[Brief explanation of the drawing]

Figures 1 to 3 show an embodiment of the present invention; Figure 1 is a longitudinal sectional view of the freezer, Figure 2 is a diagram showing the procedure for attaching the bag member, and Figure 3 is a perspective view of the freezer excluding the bag member. FIG. 4 is a diagram showing recrystallization of dry ice on the inner surface of the inner box when there is no bag member. 1...Freezer, 2...Bag member, 2a...Flap, 5...Inner box, 6...Storage room, 7...Cooling pipe,
17...Frame material.

Claims (1)

[Claims for Utility Model Registration] 1. A freezer that cools the interior of the storage chamber to an extremely low temperature, in which a metal inner box constituting a storage chamber that opens upwardly therein serves as a cooler, and has a slippery surface; A freezer comprising a bag member molded from carbon dioxide gas impermeable synthetic resin and having a shape that follows the shape of the inner peripheral surface of the inner box, provided in the storage chamber. 2. The freezer according to claim 1, wherein the bag member has a flap at the upper end. 3. The freezer as set forth in claim 1 of the utility model registration claim, characterized in that a frame member for pressing the upper part of the bag member is provided on the stepped portion formed at the edge of the opening of the storage chamber.