JP4500566B2 - Cooling method using a cooling agent - Google Patents

Description

The present invention relates to a cold-retaining method using a cold- retaining agent that is used to keep cold at a low temperature while keeping the freshness of the object to be kept cold .

In order to preserve freshness, transport and storage of fresh foods, dairy products, fresh confectionery, fresh flowers, etc. requires cold storage, and ice and dry ice are used as one means.
For example, for fresh fish, ice is mainly used as a cooling means in the distribution process from the fishing port to the market, from the market to the retail store, from the retail store to the consumer, and as a cooling means in the storage place such as the sales floor. . This is because the fresh fish can be kept cold without being dried. That is, when ice is used as a cold insulation agent, the object to be kept cold can be moisturized, and can be directly brought into contact with the object to be kept cold, so that it can be quickly cooled to an appropriate low temperature, can be handled with bare hands, and has a merit of low cost.
However, since ice becomes water when it melts, it has the disadvantage that it wets the cold container and the cold place. Further, the freshness is maintained only by cooling the ice, and there is no additional freshness maintaining effect.

On the other hand, dry ice is a solid form of carbon dioxide that sublimates even when melted at a very low temperature of -78.9 ° C, so there is no worry of direct water wetting, and carbon dioxide breathes fresh food. Since it also has a freshness-keeping effect by suppressing or preventing the growth of attached bacteria, it is often used as a cooling means.
Depending on the type of fresh food and fresh flowers such as fruits and vegetables, for example, strawberries are harvested to maintain freshness, then packed in a polystyrene foam box, sealed with dry ice and precooled. After that, they are shipped by transport vehicles with refrigeration function. This is because, in addition to maintaining freshness by cooling, the effect of maintaining freshness is further enhanced by carbon dioxide in dry ice.
Also, dry ice is often used as a cold-reserving agent for fresh confectionery and the like because it sublimates and does not become liquid even when melted, and does not wet the packaging box.
That is, when dry ice is used as a cryogen, the container is not directly wetted, and in addition to maintaining the freshness by cooling, it is possible to further maintain the freshness of the object to be cooled by carbon dioxide.
However, many of fresh foods, dairy products, fresh confectionery, fresh flowers, etc. have an optimum cold insulation temperature of about 0 to 10 ° C. Therefore, dry ice is too cold to be brought into direct contact with the object to be kept cold, so-called indirect Cooling and not suitable for rapid cooling. In addition, there was a problem in handling because it caused low-temperature burns when touched directly with bare hands. Furthermore, since it does not contain moisture, there is a drawback that it is impossible to keep the object to be kept cold.

Speaking of frozen foods, ice keeping is not possible because it requires a low temperature of about minus 20 ° C.
Moreover, in the cold insulation with dry ice, although it depends on external environmental conditions, the duration of the low temperature is relatively short, and a large amount of dry ice is required for long-term cold preservation.

As a preservation method for fresh foods and the like, a method of storing a humidification device and a nitrogen supply device in a storage container and further supplying carbon dioxide with dry ice to store the object to be stored in a low-temperature and high-humidity cold fog state has been proposed. (See Patent Document 1). However, in the storage method according to this proposal, the apparatus is large and complicated, the place where it can be used is limited, and the cost is high.
JP 2003-116460 A

  Therefore, the present invention has been made to solve the disadvantages of the conventional cold-retaining agent and cold-retaining method. That is, it is possible to provide a simple cold-reserving agent and a cold-retaining means using the cold-retaining agent, which can be kept cold while keeping the moisture in the cold-reserving container and the cold-reserving place to be minimal while maintaining moisture, excellent in freshness maintenance, and easy to handle. is there. Another object of the present invention is to provide a cold-retaining agent that can rapidly cool an object to be kept cold to an appropriate low temperature and a cold-retaining means using the cold-retaining agent. Another object is to provide a cold-retaining agent capable of maintaining a low temperature for a long time and a cold-retaining means using the cold-retaining agent.

The cold-retaining method according to claim 1 is a cold-retaining method for keeping cold at a low temperature while keeping the moisture to keep the freshness of at least any one of fresh food, dairy products, fresh confectionery and fresh flowers. The cold-retention object and a cryogen composed of a gas hydrate having a crystal structure in which a gas molecule of carbon dioxide is contained in a cage made of water molecules are contained in a sealable container, and further, it is provided with a separating means for preventing contact with water dissolved from the cold agent and the cold object. The container which can be sealed here includes a container which seals the container and does not allow the contents to come out of the container.

The cold-retaining method according to claim 2 is a cold-retaining method for keeping a frozen food of a cold object to be cooled at a low temperature, and a crystal in which the cold object and carbon dioxide gas molecules are contained in a basket made of water molecules. A cryostat having a gas hydrate having a structure of minus 25 ° C. or more and minus 15 ° C. or less is contained in a hermetically sealable container, and further, contact between water dissolved from the cryogen and the object to be kept cold in the container Is provided with separation means for preventing the above. The container which can be sealed here includes a container which seals the container and does not allow the contents to come out of the container. According to a third aspect of the present invention, there is provided the cold insulation method according to the first or second aspect, wherein after placing an insole plate as a separating means in a sealable container, a dioxide dioxide is provided between the bottom surface of the container and the insole plate. A cryogen composed of a gas hydrate with a crystal structure in which carbon gas molecules are contained in a cage made of water molecules is laid, and after placing the cold insulation object on the insole board, the insole board and the cold insulation object are A cold insulation cover formed in a bottomless box shape is covered so as to cover, and then a cold insulation tray containing the cold insulation agent is installed on the cold insulation cover.

The cold insulation method according to claim 4 is the cold insulation method according to any one of claims 1 to 3 , wherein the sealable container is a cold storage box for a transport vehicle that transports an object to be kept cold. is there. Further, the cold insulation method according to claim 5 is the cold insulation method according to any one of claims 1 to 3, wherein the sealable container is a cooler box that accommodates an object to be kept cold. .

The cold-retaining method according to claim 1 is a cold-retaining method for keeping cold at a low temperature while keeping the moisture to keep the freshness of at least any one of fresh food, dairy products, fresh confectionery and fresh flowers. The cold-retention object and a cryogen composed of a gas hydrate having a crystal structure in which a gas molecule of carbon dioxide is contained in a cage made of water molecules are contained in a sealable container, and further, provided separating means for preventing contact between the cold object the water dissolved from the cold-preserving agents. Thereby, it is possible to keep the cold object without getting wet by minimizing the wetness of the cold container or the cold place, and easily keep the low temperature for a long time and keep the cold object.

The cold-reserving method of claim 2 is a cold-retaining method for keeping the frozen food of the object to be kept cold at a low temperature, and having a crystal structure in which the object to be kept cold and gas molecules of carbon dioxide are contained in a cage made of water molecules. A cryogen having a gas hydrate of −25 ° C. or more and −15 ° C. or less is housed in a hermetically sealable container, and further prevents contact between water dissolved from the cryogen and the object to be kept in the container. Separation means were provided. Thereby, it is possible to keep the cold object without getting wet by minimizing the wetness of the cold container or the cold place, and easily keep the low temperature for a long time and keep the cold object.

The cold insulation method according to claim 4 is the cold insulation method according to any one of claims 1 to 3 , wherein the container that can be sealed is a cold storage box for a transport vehicle that transports an object to be kept cold. Therefore, it is possible to transport the cold insulation object while exhibiting the same effect as the cold insulation method according to any one of claims 1 to 3 . That is, it is possible to keep cold while keeping moisture in a cold container or a cold place while minimizing water wetting, excellent in keeping freshness, easy to handle, and transporting a cold object while keeping it cool. Alternatively, the object to be kept cold can be rapidly cooled to an appropriate low temperature, and can be transported easily while maintaining the low temperature for a long period of time.

Hereinafter, an embodiment of the cryogen of the present invention will be described with reference to the drawings.
First, FIG. 5 shows an example of a manufacturing process for producing the cold-retaining agent according to the present invention. The inside of the drum body 1 of the gas hydrate generator 5 formed as a pressure shell is maintained at a pressure of, for example, about 3.5 MPa, and water cooled to, for example, about 0 ° C. by the water cooler 2 in the drum body 1. W is supplied. When the carbon dioxide gas G is supplied from the lower part of the drum body 1, a gas hydrate H having a crystal structure in which one of the carbon dioxide G molecules is contained in the cage formed by the water molecules of the water W is generated.

  The drum body 1 is cooled by the drum cooler 4, and the carbon dioxide gas G in the drum body 1 is circulated by the gas circulation device 3 so that the gas hydrate H is easily generated.

  After the gas hydrate H is generated, the gas hydrate H is stored in the storage tank 8 with an appropriate property such as a sherbet or a powder through a dehydration process. The gas hydrate H in the storage tank 8 is cooled to an appropriate temperature by the storage tank cooler 6 while being stirred by the stirring device 14.

The storage conditions of the gas hydrate H in the storage tank 8 are, for example, a pressure of 0 to 1.2 MPa and a temperature of minus 55 to 0 ° C. More specifically, when the pressure is 0 MPa (atmospheric pressure), the temperature is minus 55 ° C., and when the pressure is 1.2 MPa, the temperature is 0 ° C. and the gas hydrate H is stored.
Therefore, the temperature of the gas hydrate H can be changed by changing the pressure in the storage tank 8.

  When the object 10 to be kept is fresh food, dairy products, fresh confectionery, and fresh flowers, a gas hydrate is used that is made of a gas hydrate H of about 0 ° C. and about −20 ° C. for frozen food. A cryogen 20 comprising H is used.

  The gas hydrate H in the storage tank 8 is supplied to the pellet molding device 12 by the supply device 7 and molded into pellets. Further, for example, when used in a powder form or a sherbet form stored in the storage tank 12, the gas hydrate H can be ejected from the ejection nozzle 16 by the supply device 7.

  Next, a first embodiment of the method of using the cold-retaining agent, that is, the cold-retaining method using the cold-retaining agent will be described with reference to FIG. A cold storage object 10 is housed in a sealed container 30 made of expanded polystyrene, and a cold storage agent 20 made of pellet-like carbon dioxide gas hydrate H at about 0 ° C. covers the cold storage object 10. In this state, the cold insulation agent 20 directly contacts the cold insulation object 10 and rapidly cools at a low temperature of approximately 0 ° C., and water W resulting from the dissolution of the cold insulation agent 20 is supplied to the cold insulation object 10 to perform moisture retention. However, since the water W contained in the cold-retaining agent 20 is very small compared to ice, the cold-reserved object 10 and the sealed container 30 are not excessively wetted. For this cold-retaining method, a cold-reserved object 10 such as seafood that requires relatively high moisture retention is suitable.

  Of course, in addition to the pellet form, a cryogen 20 such as a powder form or a sherbet form can be used. As shown in FIG. 2, it is possible to keep cold by simply bringing the cold-retention object 20 into contact with the cold-retention object 10 without storing the cold-retention object 10 and the cold-retention agent 20 in the sealed container 30. In this case, although the gas G component and the water W are diffused, this is a suitable cold insulation method when the cold insulation temperature is relatively high and the moisture retention is not so necessary.

  Next, a second embodiment of the cold insulation method will be described with reference to FIG. A cold insulating material 20 made of pellets of the cold object 10 and carbon dioxide gas hydrate H is accommodated in a sealed container 30 having a heat insulating property made of polystyrene foam to indirectly cool the cold object 10. In other words, in this embodiment, the water W dissolved from the cold insulation agent 20 is prevented from coming into contact with the cold insulation object 10. The sealed container 30 may be a general cooler box. Since the indirect cooling is performed, the temperature of the gas hydrate H serving as the cooling agent 20 can be appropriately determined.

First, a general cold insulation sheet is formed in a box shape with only the lower surface opened to form a cold insulation cover 31, and a surface fastener 33 is attached to the outer surface of the upper surface. The cool sheet is preferably a rigid sheet using a thick paper as a core material.
Next, it forms in the box shape which opened only the upper surface with the same cold insulating sheet | seat, it is set as the cold insulating agent tray 32 for accommodating the cold insulating agent 20, and the surface fastener 33 is attached to the lower surface outer side. Here, although the hook-and-loop fastener 33 is used, other things can be used if the cold-insulating tray 32 can be fixed to the cold cover 31.

An insole plate 34 is disposed on the bottom surface of the hermetic container 30, and the cooling agent 20 is placed between the bottom surface and the insole plate 34.
A cold insulation object 31 is placed on the upper surface of the insole plate 34 so as to cover the entire surface, and a cold insulation tray 32 containing the cold insulation agent 20 is provided on the upper surface of the cold insulation cover 31. It is fixed by the connection of 33.

  With this configuration, the cold insulation agent 20 cools the air in the sealed container 30 at the low temperature, indirectly cools the cold insulation object 10, and maintains freshness. Further, the carbon dioxide gas G released from the cold insulation agent 20 covers the cold insulation object 10 and improves the freshness retention effect. In order to make the best use of the effect of the cold insulating agent 20, the cold insulating cover 31 is provided with appropriate through holes and gaps to ensure the air flow in the sealed container 30.

  Since the carbon dioxide gas G is heavier than the atmosphere and easily accumulates in the lower part, it is preferable to provide the cold-retaining agent 20 above the object 10 to be kept cold, and it is more preferable to keep it cold by providing it above and below.

In this embodiment, the insole plate 34 and the cold insulation tray 32 serve as separation means for preventing contact between the water W dissolved from the cold insulation 20 and the cold insulation object 10.
Therefore, the cold insulation object 10 does not get wet with the water W dissolved from the cold insulation agent 20.
The water W dissolved from the cold-retaining agent 20 is accumulated in the cold-reserving agent tray 32 and the bottom surface of the storage container 30, and the water-recovered object 10 is moisturized by the evaporation of the water W.

  For this cold insulation method, a cold preservation object 10 that is not suitable for cold preservation by directly getting wet with water, such as meat, vegetables, fruits, dairy products, fresh confectionery and fresh flowers, is suitable. Frozen food can also be used as the cold object 10.

  Depending on the cold insulation object 10 and the cold insulation time, the height of the leg of the insole board 34 can be changed to change the amount of the cold insulation agent 20 laid on the bottom surface of the sealed container 30.

  As the cryogen 20, not only pellets of gas hydrate H but also powder or sherbet can be used.

  Next, a third embodiment of the cold insulation method will be described with reference to FIG. In this embodiment, the sealed container 30 of the second embodiment is used as a cool box 35 of the transport truck 40, and other parts are the same as those of the second embodiment.

  In this embodiment, the cold insulation object 10 and the cold insulation object 20 which consists of the pellet of the carbon dioxide gas hydrate H are accommodated in the cold insulation box 35, and the cold insulation object 10 is indirectly cooled. In other words, in this embodiment, the water W dissolved from the cold insulation agent 20 is prevented from coming into contact with the cold insulation object 10.

  Then, the cold object 10 is accommodated in the cold box 35, and the cold object 10 is transported to the destination. For example, it is transported from the harvest area to the market, from the market to the store, and from the store to the home.

  The cold insulation cover 31 is used in the form of a sheet, and a hook-and-loop fastener 33 is attached to a position on the outer side of the upper surface. As in the second embodiment, the cold insulator tray 32 and the hook-and-loop fastener 33 are attached to the outside of the lower surface thereof.

  An insole plate 34 is disposed on the bottom surface of the cool box 35, and the cold insulation agent 20 is placed between the bottom surface and the insole plate 34. Loaded. A cold insulation cover 31 is attached so as to cover the whole of the cold insulation object 10, and a cold insulation agent tray 32 containing the cold insulation agent 20 is fixed to the upper surface of the cold insulation cover 31 by bonding of the surface fasteners 33.

  With this configuration, the cold-retaining agent 20 cools the air in the cold-reservoir 35 at the low temperature, and indirectly cools the cold-reserved object 10 to maintain freshness. Further, the carbon dioxide gas G released from the cold insulation agent 20 covers the cold insulation object 10 and improves the freshness retention effect. In order to make the best use of the effect of the cold insulating agent 20, the cold insulating cover 31 is provided with appropriate through-holes and gaps to ensure the air flow in the cold storage 35.

  As in the second embodiment, the cold-retaining agent 20 is preferably provided above the cold-retention object 10, and more preferably provided at the upper side and the lower side to keep cold.

In this embodiment, the insole plate 34 and the cold insulation tray 32 serve as separation means for preventing contact between the water W dissolved from the cold insulation 20 and the cold insulation object 10.
Therefore, the cold insulation object 10 does not get wet with the water W dissolved from the cold insulation agent 20.
The water W dissolved from the cold-retaining agent 20 is accumulated in the cold-reserving agent tray 32 and the bottom surface of the storage container 30, and the water-recovered object 10 is moisturized by the evaporation of the water W.

  For this cold insulation method, a cold preservation object 10 that is not suitable for cold preservation by directly getting wet with water, such as meat, vegetables, fruits, dairy products, fresh confectionery and fresh flowers, is suitable. Moreover, frozen food can also be used as the cold storage object 10.

Depending on the cold insulation object 10 and the cold insulation time, the height of the leg of the insole board 34 can be changed to change the amount of the cold insulation agent 20 laid on the bottom surface of the sealed container 30. In addition, the number of the cooling agent trays 32 that store the cooling agent 20 is changed as necessary.
As the cooling agent 20, powdery or sherbet-like gas hydrate H can be used. In this case, as shown in FIG. 5, the cooling agent 20 is sprayed from the ejection nozzle 16 to the freezer 35 and the cooling agent 20 is spread. Can be pre-cooled.

  When the object 10 to be kept cold is seafood or the like, the object 10 can be kept cool by directly contacting the object 10 to be kept in cold contact with the coolant 20.

  The cold-reserving agent 20 and the cold-retaining method using the cold-retaining agent 20 according to the present invention can be used to keep the cold-reserved object 10 moisturized while keeping the freshness of the cold-retained object 10 at a low temperature. In addition to the above, frozen confectionery, serum, medicine, and the like can be used as the cold storage object 10.

It is a section explanatory view showing a first embodiment of a cold insulation method according to the present invention. It is explanatory drawing which shows the modification of 1st embodiment of the cold insulation method which concerns on this invention. It is explanatory drawing which shows 2nd embodiment of the cold insulation method which concerns on this invention. It is explanatory drawing which shows 3rd embodiment of the cold insulation method which concerns on this invention. It is explanatory drawing which shows an example of the manufacturing process for producing | generating the cold insulating agent which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drum main body 2 Water cooler 3 Gas circulation device 4 Drum cooler 5 Gas hydrate production | generation apparatus
6 Storage tank cooler 7 Supply device
8 Storage tank 10 Cold storage object
12 Pellet molding equipment 14 Stirring equipment 16 Ejection nozzle 20 Coolant
30 Sealed container (Styrofoam box) 31 Cooling cover
32 Coolant tray 33 Hook fastener 34 Insole plate 35 Cold storage 40 Transport truck

Claims (5)

A cold-retaining method for keeping cold at a low temperature while keeping the freshness of at least one of fresh food, dairy products, fresh confectionery and fresh flowers, wherein the cold-retention object and carbon dioxide A cryogen composed of a gas hydrate having a crystal structure in which a gas molecule is contained in a cage made of water molecules is housed in a sealable container, and the water dissolved from the cryogen in the container and the cold insulator A cold insulation method provided with separation means for preventing contact with an object. A cold-retaining method for keeping frozen food of a cold-reserved object at a low temperature, the gas-hydrate having a crystal structure in which the cold-retained object and a gas molecule of carbon dioxide are contained in a basket made of water molecules is minus 25 ° C. or higher. A cold insulation method in which a cryogen kept at minus 15 ° C. or less is housed in a sealable container, and further, separation means is provided in the container to prevent contact between water dissolved from the cold insulator and the object to be kept cold. After placing an insole plate as a separating means in a sealable container, a gas hydrate having a crystal structure in which gas molecules of carbon dioxide are contained in a cage made of water molecules between the bottom surface of the container and the insole plate Cover with a cold insulation agent, and then place a cold insulation object on the insole board, and then cover the cold insulation cover formed in a bottomless box shape so as to cover the insole board and the cold insulation object, then on the cold insulation cover The cold-retaining method according to claim 1 or 2, wherein a cold-retaining agent tray containing the cold-retaining agent is installed. The cold-reserving method according to any one of claims 1 to 3, wherein the airtight container is a cold-reservoir of a transport vehicle that transports a cold-reserved object. The cold-retaining method according to any one of claims 1 to 3, wherein the airtight container is a cooler box that accommodates an object to be kept cold.

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