JPH0633853B2 - Insulation structure - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a heat insulating structure applied to a container or the like for storing a low temperature liquid such as a low temperature liquefied gas.

[Prior art and its problems]

As a heat insulating structure to be applied to a container containing a fluid having a relatively high temperature, for example, a heat insulating block made of a foamed hard resin such as urethane foam can be achieved by adhering it to the outer surface of the container. , As a container for storing low-temperature liquefied gas such as liquid oxygen, liquid nitrogen, liquid natural gas, etc. at extremely low temperatures, or as a heat insulating structure (or heat insulating method) applied to a low temperature fluid transfer pipe, etc. These methods are not suitable from the viewpoint of heat insulation performance.

What is conventionally used as a heat insulating structure to be applied to a container containing a low temperature fluid is, for example, the most basic method is to fill a hollow part such as a double walled tank wall with a heat insulating substance such as pearlite powder. As a method for further improving the heat insulating performance of the pearlite powder, a method has been performed in which the heat insulating material is filled and then the portion is evacuated.

However, when these methods or structures are used, it is pointed out that the effect of radiant heat through the gaps between the particles of the filled perlite powder cannot be prevented.

In particular, in the heat insulation method by this method, the heat conductivity is 1/2 to 1/3 of that of ordinary plastic foam.
Although it has excellent performance, it has a problem that heat loss due to radiation is large because its use place (application place) is used at a place where the temperature difference between the low temperature liquefied gas and the outside air is large.

As a method of solving such a problem of radiation and further improving its cross-sectional performance, aluminum powder in pearlite powder,
A method called microsphere heat insulation is developed in which metal powder such as copper powder is mixed and dispersed, or hollow glass spheres plated on the outer surface are filled in pearlite powder and then vacuum exhaust is performed. Although the respective tentative effects can be obtained, the former has a problem that it is difficult to uniformly disperse the pearlite powder and the metal powder in the powder because of a difference in particle size and specific gravity. In addition, since a large amount of metal powder is required to uniformly disperse the metal powder in the pearlite powder, it has an adverse effect in terms of weight and cost, and also in terms of physical properties, locations where the temperature difference is small. On the contrary, there is a drawback that the result that the thermal conductivity becomes lower when the metal powder is not filled is obtained.

In addition, in the case of microsphere insulation, there is a drawback that it is too expensive for industrial use,
If the filling pressure is high, there is a drawback that the glass spheres not plated have a lower thermal conductivity as in the case of filling the metal powder.

Furthermore, although it is a completely different application as a load supporting structural material for a magnetic levitation train (linear motor), a heat insulating load structural material in which a metal foil and a spacer are laminated in a heat insulating material having a honeycomb structure. Although it was proposed (JP-A-54-2)
1655), in this structure, since a large number of metal foils are laminated in one space, there is a lateral connection, and there is a drawback that the thermal conduction in the lateral direction becomes large and the blocking effect is lost. there were.

Further, since the heat radiation blocking material used in the present invention is a single piece of metal foil, wrinkles easily occur during molding when the thickness of the metal foil used is thin, and handling is difficult, and it is used conversely. When the metal foil is thick, it becomes hard and difficult to handle and also has the drawback of further increasing heat conduction, and when a soft synthetic resin bag like the present invention is applied to a container, the container bag is damaged. It is pointed out that the function is lost.

[Object of the Invention]

The present invention has been made in view of these circumstances and seeks to cope with it. The heat insulating structure can block the influence of radiation, is less affected by heat due to radiation, and has an extremely excellent heat insulating effect. Is intended to be provided.

Another object of the present invention is that the manufacturing means is simple, and the manufactured heat insulating structure is extremely easy to be reprocessed on site such as cutting the peripheral portion of the block body appropriately shaped according to the application place. It is intended to provide a heat insulating structure.

[Main points of the invention]

The present invention has a film thickness of 200Å on at least one surface by vapor deposition.
In the container made of synthetic resin film on which the above metal film is formed,
A powdery heat insulating material is filled, and synthetic resin film pieces having the same structure as the container are arranged in the filled powdery heat insulating material in a direction intersecting with a heat transmission direction and face the same. It is an essential point of the invention to form a large number of heat insulating structures scattered in the interior of the container, and to evacuate the air present in these containers as necessary.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

In the examples, FIG. 1 shows an example in which a synthetic resin film is used as a container, and FIG. 2 shows an example in which a foamed synthetic resin skin is further formed on the outside of the example shown in FIG.

The heat insulating structure generally indicated by A has a powder heat insulating material 2 filled inside a container 1 made of a synthetic resin film having a metal film surface formed on at least one surface thereof, and the filled powder filling material. In the inside of 2, the same material as the container 1 is used,
A large number of synthetic resin film pieces 3 ... 3 subjected to metal vapor deposition are scattered.

The container 1 filled with the powder heat insulating material 2 and the metal vapor-deposited film pieces 3 ... 3 is a synthetic resin whose inside is kept in a vacuum state by performing vacuum evacuation from one of the container 1 and the mouth of the container 1. Welding is closed.

The synthetic resin film pieces 3 ... 3 on which the metal film surface is formed are arranged and dispersed in the powder heat insulating material 2 so as to intersect the radiation heat transmission direction and face the powder heat insulating material 2 when used. When the arrangement is such that the synthetic resin film pieces 3 ... 3 are randomly mixed in the powder and then pressure is applied from the upper surface of the container 1, the synthetic resin film pieces 3 ...
Can be laid down in the powder heat insulating material 2 and easily positioned in a direction intersecting with the pressing direction.

Therefore, it is desirable that the container 1 is pressurized from the same direction as the radiant heat transmission direction when the container 1 is used.

Further, according to the experimental results, the size of the synthetic resin film pieces 3 ... 3 on which the metal film surface is formed is at least 0.1 cm ^{2 to} 400 cm ²
Of the fine powder which is the heat insulating material 2
The object was able to be achieved by mixing in the ratio of 60% by weight to 60% by weight.

The area of the synthetic resin film piece 3 used is 400 cm.
^In the case of a large one such as 2, the synthetic resin film 3 is obtained by laying one layer of the powder heat insulating material 2 to a predetermined thickness on the upper surface of the film to be the container 1, and then forming the film surface thereon.
, The powder heat insulating material 2 is spread over the upper surface again by a predetermined thickness, and the synthetic resin film piece 3 on which the film surface is formed is spread over the upper surface again. It is also possible to obtain a heat insulating structure in which a permeation preventive layer is formed.

Reference numeral 4 denotes a protective outer cover of foamed synthetic resin formed on the outer surface of the container 1. The container 1 is mixed with the powder heat insulating material 2 and the synthetic resin film pieces 3 ... 3 having a film surface formed by metal deposition or lamination. After completing the basic insulation structure,
It is formed by foaming and injecting it to the outside with a desired thickness.

In the present invention, vinyl chloride resin, polyester resin, polyamide resin, polyolefin resin, polystyrene and the like are suitable as the synthetic resin film used as the container 1 or the synthetic resin film piece 3. The material of the metal film surface to be vapor-deposited or laminated on this synthetic resin film is copper, aluminum, gold, silver,
Tin, chromium, etc. are suitable.

The thickness of the metal film formed by vapor deposition on the surface of the synthetic resin film is preferably at least 200 Å or more in view of the effect on radiation.

It should be noted that the surface of the metal film applied to the synthetic resin film may be one surface of the synthetic resin film, but it is more preferable to form the metal film on both surfaces in order to maintain the effect of blocking radiation for a long time.

In terms of cost, a plastic film on which aluminum is vapor-deposited is the most economical.

The particle size of the powder heat insulating material 2 to be filled in the container 1 is 50
Fine powder of less than μm, for example, Shirasu balloon, perlite, titania, Santocel, calcium silicate, magnesium carbonate, diatomaceous earth, fine silica, or glass wool,
It is effective to use fibrous materials such as rock wool and asbestos.

In particular, among the above materials, finely divided silica has good adsorption performance for organic vapor and water vapor, is particularly good for long-term vacuum fiber, and has a low thermal conductivity as compared with other fine powders even under normal pressure and has an excellent effect. It has been proved as a result of an experiment that it has

[Example 1] Perlite powder 3 dried in a thermostatic bath at 110 ° C for 48 hours
In 00 gr, 6 gr of polyester resin film pieces having aluminum vapor-deposited surfaces on both sides are uniformly mixed,
Disperse it and store it in a bag made of aluminum-deposited polyester resin, press it with a press machine, and place the mixed synthetic resin film pieces in a direction crossing the pressing direction and horizontally with the pressing surface. After that, the opening was closed by heat welding means to obtain a heat insulating structure of 200 mm × 200 mm × 25 t.

Both the structure of Example 1 and the heat insulating structure (Comparative Example 1) excluding the metal vapor deposition film from Example 1 and composed of only pearlite powder for comparison, were made by Anacon. When the thermal conductivity was measured by a measuring device “K factor”, the structure ... thermal conductivity [Kcal / mhr ° C.] Example 1 …… 0.040 Comparative Example 1 …… 0.045 (however, average temperature 23 ° C.) It was confirmed that Example 1 was superior.

[Example 2] Perlite powder 3 dried in a thermostatic bath at 110 ° C for 48 hours
In 00 gr, 6 gr of polyester resin film pieces having aluminum vapor-deposited surfaces on both sides are uniformly mixed,
Disperse it and store it in a bag made of aluminum-deposited polyester resin, press it with a press machine, and place the mixed synthetic resin film pieces in a direction crossing the pressing direction and horizontally with the pressing surface. After that, place it in a vacuum suction device, evacuate to a pressure of 0.01 Torr, and then close the opening in the vacuum device by heat welding means to form a 200 mm x 200 mm x 25 t heat insulation structure. Got

Both the structure of Example 2 and the heat insulating structure (Comparative Example 2) manufactured by excluding the metal vapor-deposited film from Example 2 and composed only of pearlite powder for comparison were heat produced by Anacone. When the thermal conductivity was measured by a conductivity measuring device “K factor”, it was found that the structure ... thermal conductivity [Kcal / mhr ° C.] Example 2 …… 0.0060 Comparative Example 2 …… 0.0083 (However, the average temperature 23 C.) and Example 2 were confirmed to be superior.

[Example 3] Perlite powder 3 dried for 48 hours in a constant temperature bath at 110 ° C
In 00 gr, 6 gr of polyester resin film pieces having aluminum vapor-deposited surfaces on both sides are uniformly mixed,
Disperse it and store it in a bag made of aluminum-deposited polyester resin, press it with a press machine, and place the mixed synthetic resin film pieces in a direction crossing the pressing direction and horizontally with the pressing surface. After that, place it in a vacuum suction device, evacuate to a pressure of 0.01 Torr, and then close the opening in the vacuum device by heat welding means to form a 200 mm x 200 mm x 25 t heat insulation structure. Got

The above structure was further placed in a 205 mm × 205 mm × 35 t acrylic mold, and urethane foam resin was injected and filled around the frame to obtain a heat insulating structure with a protective outer cover.

When the thermal conductivity of the structure of Example 3 was measured by a thermal conductivity measuring device “K Factor” manufactured by Anacon, the structure ... Thermal conductivity [Kcal / mhr ° C.] Example 3 ... 0.0085 (However, the average temperature was 23 ° C), which was excellent.

〔The invention's effect〕

The effects of the present invention configured as described above are as described above.

(1) By mixing the synthetic resin film pieces 3 ... 3 having the metal film surface formed by vapor deposition means into the powder heat insulating material 2, it is possible to very effectively shield the radiant heat in the powder heat insulating material. Thus, it was possible to completely prevent the adverse effect of radiant heat that the conventional cross-section structure had.

(2) The synthetic resin film pieces 3 ... 3 having a metal film surface mixed in the synthetic resin bag and the powder heat insulating material 2 constituting the container 1 have a film thickness of 200Å on at least one surface by vapor deposition.
Since it is composed of the synthetic resin film formed with the above metal film, it has moderate elasticity compared to the one using the metal foil alone, so that it does not bend or deform even when pressed and powder insulation Dispersion and mixing in the material can be carried out easily and accurately, and the manufacturing cost therefor can be made extremely low.

(3) The weight can be made extremely light compared to the conventional product in which metal powder and the like are mixed, which is advantageous in terms of manufacturing cost and widens the application place of the product.

(4) In the case of the conventional heat insulating structure, since the entire structure is a vacuum panel structure, it is almost impossible to modify the heat insulating structure at the construction site. When the outer shell of the foamed synthetic resin is formed, it is possible to cut them on site and process them while matching them on site, and it is possible to achieve complete application to the construction site.

(5) The vacuum state formed in the container 1 can be maintained for a long period of time, and the heat insulation effect can be maintained correspondingly for a long period of time.

(6) When the vacuum suction is performed, the container 1 in which the powder heat insulating material 2 and the synthetic resin film pieces 3 ... Having the metal film surface are mixed can perform suction while performing desired deformation. It has become possible to obtain various deformed heat insulating structures while using them. Therefore, the container 1 in which the synthetic resin film pieces 3 with metal film surfaces 3 ... If vacuum suction is performed while conforming to the shape of the heat insulating structure, the heat insulating structure does not require a mold or the like, and it is possible to instantly obtain a heat insulating structure having a complicated shape.

[Brief description of drawings]

1 shows an embodiment of the present invention. FIG. 1 is a vertical cross-sectional side view, and FIG. 2 is a vertical cross-sectional side view showing an example in which an outer cover of foam synthetic resin is formed. A ... Insulation structure, 1 ... Volume, 2 ... Powder insulation, 3
...... Synthetic resin film pieces with a metal film surface, 4 …… Protective skin.

Claims (6)

[Claims] 1. A film thickness of 200 is formed on at least one surface by vapor deposition.
Å The container made of synthetic resin film with the metal film formed above is filled with the powder heat insulating material, and the filled powder heat insulating material is filled with a synthetic resin film piece having the same configuration as that of the container. A large number of heat insulating structures arranged in a direction intersecting with the transmission direction and scattered so as to face the same. 2. The heat insulating structure according to claim 1, wherein the outer periphery of the container is covered with an outer cover made of a foamed synthetic resin having a predetermined thickness. 3. The container after filling and containing the powder heat insulating material and the synthetic resin film piece formed with a metal film surface is one in which the inside is evacuated by vacuum suction and then the opening is closed. The heat insulating structure according to any one of the first and second aspects. 4. The metal material to be vapor-deposited or laminated on the film surface is selected from any one of copper, aluminum, gold, silver, tin, chromium and the like. The heat insulating structure according to any one of items. 5. The powder heat insulating material is shirasu balloon, perlite, titania, santocell, calcium silicate, magnesium carbonate, diatomaceous earth, fine silica, or glass wool,
The heat insulating structure according to any one of claims 1 to 3, which is either rock wool, asbestos or a mixture thereof. 6. The heat insulating structure according to claim 1, wherein the powder heat insulating material used has a particle size of 50 μm or less.