JPS63318398A - Superlow temperature container - Google Patents

Abstract

PURPOSE:To improve the heat insulating effect by forming a multilayered heat insulating part from the heat insulating sheets laminatated in mutilayer form and allowing adsorbent to be interposed in dispersed state between the heat insulating sheets. CONSTITUTION:A multilayered heat insulating part 9 which is formed by laminating the heat insulating sheets 8 is formed on the surface of an inner tank 1, and a vacuum part 7 is formed between the surface of the multilayered heat insulating part 9 and an outer tank 2, and adsorbent 10 is interposed in the dispersed state between the heat insulating sheets 8. Therefore, the gas in the gap between the mutilayered heat insulating part is adsorbed, and the vacuum degree in the gap is improved, and the superior heat insulating effect can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention accommodates a low-temperature substance and attempts to insulate it (Φ).

(Prior Art) In order to insulate a cryogenic container, it is essential to reduce heat intrusion from the outside as much as possible. Generally, the sum Q1 of heat penetrating into the container is given by the following equation.

Q = Q, +Q +Q ・・・・・・(1)
T + rc However, Q: Molecular heat conduction Q: Heat radiation Qo Two solid heat conductors Conventionally, in order to reduce Q in equation (1), a heat insulating material such as Aayhv film with a low emissivity is used as a container. An idea has been devised to form a multilayer heat insulating section by wrapping the material around the material multiple times.

Further, in order to reduce Q in the above equation 1), a container has been proposed in which the inside of the multilayer heat insulating section formed as described in 1.E is made into a high vacuum. Figure 10 also shows the relationship between the atmospheric pressure and average thermal conductivity within the multilayer insulation section, where the solid line shows the case when AQ vapor-deposited polynysyl film is used as the insulation material in an air atmosphere, and the broken line represents the insulation material. shows the case where AQ foil is used in a helium atmosphere, but in both cases, the average thermal conductivity decreases due to the decrease in air pressure outside the container,
It can be seen from this figure that it becomes almost constant below 10-4 n1 bar.

Furthermore, in addition to such means, as shown in FIG. 11, a <1 net-shaped spacer 101 may be sandwiched between the heat insulating materials 102, and as shown in FIG. 12, protrusions may be formed on the heat insulating material 103 itself. Or for example, Jikko Sho 60-135
5 By attaching a protruding member as shown in the f'3 publication to the heat insulating material, a gap is formed between the IfJi heat shrines, and Q of equation (1) is satisfied. At the same time, gases desorbed from the surface of the insulation material (mainly N2, 02
, 1-120, etc.) have been developed in the Near East to make them easier to remove and to increase the degree of vacuum.

However, even if a gap is provided between the insulation materials, if the gap is made extremely large, the overall scale of the container will increase, resulting in a wasteful structure, so the gap is generally about 0.1 It is about 0.2 mm, and it is not easy to create a high vacuum by letting gas escape from such a small gap. Accordingly, in the past, it took a long time to create a high vacuum inside the heat insulation section, and 1! ? The degree of vacuum obtained was also not satisfactory.

(Object of the Invention) In view of the above-mentioned circumstances, the present invention has been devised to provide insulation inside the heat insulating section surrounding the inner tank.
By improving the garden, you will have an excellent place to heat up the Song Dynasty! [1] It is an object of the present invention to provide a cryogenic container capable of

(Structure of the Invention) The present invention consists of an inner tank that accommodates a low-temperature substance and an outer tank that accommodates the inner tank. In the cryogenic container in which a vacuum section is formed between the inner tank and the inner tank, the multilayer insulation section is formed of heat insulation sheets laminated in multiple layers, and the multilayer insulation section has a space between the insulation sheets at least in a peripheral portion of the inner tank. Adsorbent is interposed in a dispersed state between the heat insulating sheets, and gaps are formed between the heat insulating sheets.

According to this configuration, the adsorbent cooled by the low-temperature substance housed in the inner tank adsorbs the gas within the multilayer heat insulation section, so that the degree of vacuum within the multilayer heat insulation section increases.

(Example) FIG. 1 shows eight cryocoolers of the present invention. Same contents each, inner tank 1
, and outer If12 to 4j that accommodate this inner tank 1,
A sealing member 3a is sandwiched between the flange 4 and the upper surface of the outer tank 2.
is fixed by bolts 5, and the upper surface of the inner tank 1 is fixed to the flange 4 with a seal member 3b interposed therebetween. The seal member 3a seals the outside of the container and the inside of the outer tank 1fg2, and seals the space between the outer tank 2 and the inner tank 1 and the inside of the inner tank 1. The flange 4 has a communication port 4a that communicates with the inside of the inner tank 1, and a low-temperature substance 1- such as liquid nitrogen or liquid oxygen is injected into the inner tank 1 through the communication port 4a. be accommodated.

A multilayer heat insulating section 9 is provided on the surface of the inner tank 1, which is formed by laminating heat insulating films (insulating sheets) 8 such as polynisdel films. A vacuum pump (not shown) is connected to the outer tank 2 via a valve 6, and the vacuum pump 1 causes a gap between the surface of the multilayer insulation part 9 and the outer IfI2. A vacuum section 7 is formed.

Regarding the side part of the inner tank 1, the multilayer insulation part 9 has a heat insulating film 8 wrapped around the side face of the inner tank 1, and the upper part of the heat insulating film 8 is folded inward so as to cover the upper part of the inner IP+1. The bottom part of the inner tank 1 is formed by laminating a heat insulating film 8 cut into the same shape as the bottom part, called "C", and wrapping the edge of the heat insulating film around the side surface of the inner tank 1. It is formed by combining 8 and 8.

Furthermore, in such a multilayer insulation part 9, the inner tank 1
A granular adsorbent 10 welded to the surface of the film 8 is interposed between the heat insulating films 8 in the peripheral area (the inner part of the multilayer heat insulating part 9), and a gap is formed by the adsorbent 10. 1. As the adsorbent 10, activated carbon, silica gel, mole sieve, and zeolide W can be used.
J] will improve your name-taking ability. Adsorbent 10
Regarding the installation procedure, it is sufficient to melt the adsorbent 10 in advance by heating it to about 1000C to 4000G> above the melting point of the heat insulating film 8, and then spraying it onto the heat insulating film 8. By laminating the heat insulating film 8 to which the adsorbent 10 has been welded in this way, the contact portion with the heat insulating film 8 is melted and as it cools, it is welded to the surface of the heat insulating film 8 as shown in FIGS. 2 and 3. , a structure as shown in FIG. 1 is obtained.

a3. In order to enhance the heat insulation effect, it is preferable to use a polymer film with Δρ vapor-deposited on the surface as the heat insulation film 8. However, when such a film is used, the Ap@ vapor deposition may be performed on one side, and the adsorbent 10 may be sprayed on the back side.

The range in which the adsorbent 10 is provided is determined by taking into consideration the predicted temperature distribution of the multilayer heat insulating section 9. In other words, the adsorption capacity of the adsorbent 10 improves as the temperature decreases, so the low-temperature substance accommodated in the inner tank 1 has a predetermined temperature (
Here, the cover should be provided in a range where it is cooled to below about 150 to 200K.

The part of the multilayer heat insulation part 9 located around the inner tank 1 is formed by such thermal film 8 with adsorbent 10, but the part other than this, that is, the outer part, is covered with adsorbent 10. The insulation film 8 is used!も、
By interposing a spacer 11 made of, for example, a polymer net between ordinary heat insulating films 8, a gap is formed between the heat insulating films 8.

In such a container, when the inside of the outer tank 2 is evacuated by the vacuum pump while the inner tank 1 is empty, a vacuum section 7 with a pressure of 10-5 mbar or less is created between the multilayer insulation part 9 and the outer tank 2. is formed, but at this time, gases such as nitrogen, M wood, and water vapor adhere to the surface of the heat insulating film 8, so that the pressure inside the multilayer heat insulating part 9 drops only to 10-2-101 abar. However, when a low-temperature substance is injected from the injection port 4a of the flange 4, and the multilayer insulation section 9 around the inside 1f11 is cooled by this, the adsorption capacity of the adsorbent 10 disposed on the insulation film 8 increases. , the same adsorbent 10
adsorbs the desorbed gas, the pressure inside the multilayer heat insulating section 9 drops significantly and becomes a high vacuum state.

4 to 6 show the results of experiments conducted under the following conditions.

Adsorbent: Activated carbon (particle size 0.5 mm) Insulation material 2 Q vapor deposited flat film Number of layers of multilayer insulation part: 30 Inner 15 layers... Insulation with adsorbent Outer 15 layers... General Insulating material In these figures, Fig. 4 shows the case where the adsorbent 10 is not used and no cooling is performed, Fig. 5 shows the case where the adsorbent 10 is not used but a cold film is used, and Fig. 6 shows the case where the adsorbent 10 is not used and cooling is performed. It shows the relationship between time and pressure inside the container when using agent 10 and cooling, and each solid line 40, 50, 60 indicates inner tank 3.
The broken lines 41, 51, and 61 indicate the pressure within the vacuum section 7, respectively. As shown by the broken lines 41, 51, and 61, under any conditions, the pressure inside the vacuum section 7 is finally reduced to a very low pressure of about 10-5 to 10-6 n+bar.

As shown by solid lines 40.50 in FIG. 4 and FIG.
While only the mbar culm can be depressurized, the solid line 6 in Figure 6
As shown in Fig. 0, if an adsorbent is used and cold injection J1 is performed, the pressure can be reduced to a constantly low pressure of 10-4 to 10-5 mbar.

By obtaining such a high vacuum, the pottery has excellent preheat efficiency. Figure 7 shows the temperature valve 1 in the multilayer insulation section 9 when liquid helium is contained as a low-temperature substance.
1, but as can be seen from this figure, the surface of the inner tank 1 can reach a value of 14, which is almost OK (Kelvin). In other words, according to this container, without enlarging the gap between the films 8, it is possible to easily obtain a high vacuum by utilizing the action of the adsorbent 10 which is cooled by the low-temperature material. It can improve the heat insulation effect.

In the above embodiment, the adsorbent 1 is applied to the surface of the heat insulating film 8.
However, as shown in FIGS. 8 and 9, an adsorbent 10 is welded to the spacer 11, and this spacer 11 is interposed between the heat insulating films 8 in the peripheral area of the inner If 171. You can do it like this. However, if the adsorbent 10 is directly welded to the heat insulating film 8 as described above, the suction agent 10 will function as a spacer as it is, so there will be no need to provide a new spacer, and the structure will be simpler. Become something.

The range in which the adsorbent 10 is used is the type of adsorbent 1o, cold) J
The adsorbent 10 may be appropriately set depending on the temperature, etc., and for example, the adsorbent 10 may be used over the entire area of the multilayer heat insulating section 9.

In addition, the present invention is applicable to large-scale containers, regardless of the scale and shape of the container to which it is applied, as long as the outer tank 2 can be emptied 9 times vertically as described above. .

(211 Results of the Invention) As described above, according to the present invention, the gas in the gap of the multilayer insulation part is adsorbed by the adsorbent cooled by the low-temperature material contained in the inner tank. The degree of vacuum within the gap is improved, which makes it possible to reduce the insulation effect by 1.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a cryogenic container according to an embodiment of the present invention, Fig. 2 is a perspective view of a heat insulating film and adsorbent constituting the multilayer insulation part of the container, and Fig. 3 is a 1111 heat insulating film and adsorbent. Figures 4 to 6 are graphs showing the relationship between pressure and time in multilayer insulation, Figure 7 is a graph showing temperature distribution within the multilayer insulation, and Figure 8 is a graph showing the relationship between adsorbent and time in other examples. A perspective view showing the spacer in an arranged state;
Figure 9 is a cross-sectional view taken along the line IX-IX in Figure 8, Figure 10 is a graph showing the Ill relationship between the pressure within the heat insulating layer and the average thermal conductivity, and Figure 11 (a) is the heat insulation used in the past. A perspective view of the film and the net spacer, FIG. 12(b) is a cross-sectional view showing the insulating film and the net spacer stacked together, and FIG. The perspective view and the same figure (b) are sectional drawings showing the means by which the same heat insulation film was piled up. 1... Inner tank, 2... Outer tank, 7... Vacuum section, 8...
・Insulation film (insulation sheet), 9...multilayer insulation part,
10...4 absorbent, L...low) island substance. Patent Applicant: Kobe Steel, Ltd. Agent, Patent Attorney Etsushi Kotani, Patent Attorney, Chief 1) Masayuki, Patent Attorney Kurio Itaya No. 1 Figure 2 Figure 4 Figure Special Whisper (hr) Figure 5 Figure 6 Figure Special Il /1(hF) Fig. 7 """ 1iWr Heat H11/!, 7+ <41
Figure 8 Figure 9 n θ Medical 1

Claims (1)

[Claims] 1. Consisting of an inner tank containing a low-temperature substance and an outer tank containing this inner tank, a multilayer insulation part is formed on the surface of the inner tank, and a vacuum part is formed between this multilayer insulation part and the outer tank. In the cryogenic container to be formed, the multilayer insulation part is formed of heat insulation sheets laminated in multiple layers, and an adsorbent is interposed in a dispersed state between the insulation sheets in at least a peripheral portion of the inner tank of the multilayer insulation part. A cryogenic container characterized in that a gap is formed between the heat insulating sheets.