JPS6288378A - Cryogenic container - Google Patents

Abstract

PURPOSE:To eliminate trouble when trouble occurs in a cooling apparatus without heating the entire cryogenic container, by attaching the cooling apparatus to a main body through bellows and tightening members, whose length can be adjusted, and forming a connecting part in a thermal contact structure, which can be attached and detached. CONSTITUTION:A cooling apparatus 1 is attached to a part of a vacuum container 2a, which is an outer wall of a cryogenic container body 2 through bellows 4. The length of studs 3 is adjusted with a flange. The cooling apparatus 1 is thermally connected to the cryogenic container body 2. A first stage 5 of the cooling apparatus 1 is plane-contacted with the tapered surface of a first port 6 at a first shield 2b surrounded by the vacuum container 2a. A second stage 7 is plane-contacted with the tapered surface of a second port 8 at a second shield 2c. The plane contact is performed in an atmosphere in a vacuum region 9. Within the second shield 2c, a liquid well 2d, which is filled with a cryogenic fluid 10, is arranged. The surfaces of the shields 2b, and 2c and the liquid well 2d are wrapped with multilayer heat insulating material 11.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a cryogenic container equipped with a refrigeration device.

[Technical background of the invention and its problems]

In order to reduce the invading heat as much as possible, cryogenic containers such as conventional cryostats are equipped with radiation shields, such as nitrogen shields that utilize the temperature of liquid nitrogen or shields that utilize the latent heat of evaporated gas of liquid helium. is commonly used. There were two types of these shields: those that used the latent heat of the liquid or gas as described above for cooling, and those that used externally powered refrigeration equipment to forcibly cool the shield.

The former type of cryogenic container that utilizes the latent heat of a liquid or gas requires a circuit in which a medium to be cooled to cool the shield circulates or flows, and a storage tank to store the medium. For this reason, this type of cryogenic container is complicated and difficult to miniaturize, and it is necessary to replenish the cooling medium in the storage tank. Furthermore, if a problem occurs in the circuit that cools the shield, for example if the flow path is clogged with impurities and the refrigerant stops flowing, this shield will no longer work effectively, so the entire cryogenic container must be removed to correct the problem. Had to warm it up.

Next, the latter conventional cryogenic container will be explained with reference to FIG. Reference numeral 2 denotes a cryogenic container main body, and the cryogenic container main body 2 has a multilayer structure consisting of a vacuum container 2a, a first shield zb, a second shield 2C, and a liquid reservoir 2d from the outside. Note that a vacuum region 9 is provided between each of the first shield 2b, second shield 2C, and liquid reservoir 2d.

A first shield 2 is attached to such a cryogenic container main body 2.
A cooling device 1 is attached to cool the shield 2C and the second shield 2C. The cooling device 1 is mounted on a boat (a first boat 6a) each equipped with a bellows for mitigating thermal contraction, so that the first stage 5 and the second stage 7 of the cooling device 1 are attached to the first shield 2b and the second shield 2C. and is fixed to the second boat 8a) with bolts or the like so that sufficient thermal contact can be made.

In this way, cryogenic containers that use the latter type of refrigeration system have thermal contact with the part of the refrigeration system that generates a constant temperature in order to cool the shield, thereby removing the heat load on the shield. was. This method does not require a cooling circuit unlike the former method, as long as there is sufficient thermal contact between the refrigeration device and the shield. In addition, unlike the former method, there is no need for a storage tank for refrigerant, and the structure is simple and compact, which has many advantages. However, in terms of long-term reliability, these refrigeration systems still have problems such as mechanical wear and clogging due to impurities, and failures may occur for some reason. In this case, in order to correct this problem, it is only necessary to heat the refrigeration device 1, but since the refrigeration device 1 is fixed with the first shield 2b and the second shield 2e with K bolts, etc., heating the refrigeration device 1 is necessary. As a result, even the first shield 2b and second shield 2C of the cryogenic container main body 2 had to be heated, and as a result, the entire cryogenic container had to be heated.

[Purpose of the invention]

An object of the present invention is to provide a highly flexible cryogenic container that can eliminate the problem without heating the entire cryogenic container even if a problem occurs in shield cooling of the cryogenic container. do.

[Summary of the invention]

In order to achieve the above object, the present invention includes a liquid reservoir for storing a cryogenic fluid, a shield disposed around the liquid reservoir,
A cryogenic container is provided with a cooling device that cools the shield by bringing it into thermal contact with the shield, and a cooling device is attached to the cryogenic container main body, which includes a vacuum container that covers the shield, and the cooling device is connected to a bellows and a length-adjustable fastening member. The cooling device is attached to the main body of the cryogenic container, and the connection between the cooling device and the shield is made into a removable thermal contact structure, so that if a problem occurs in the cooling device, this problem can be resolved without heating the entire cryogenic container. To provide a cryogenic container that can be used to overcome low temperatures.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to FIG.

Note that the same parts as in FIG. 2 are denoted by the same reference numerals, and the description thereof will be omitted. Reference numeral 2 denotes a cryogenic container main body, and a refrigeration device 1 is attached to a part of the vacuum container 2a, which is the outer wall of the cryogenic container main body 2, by adjusting the length of the stud 3 with a 7-lung joint with a bellows 4 arranged thereon. It is being

This refrigeration device 1 has a tapered surface of a first boat 6 in a first shield 2b surrounded by a vacuum container 28 and a tapered surface of a second boat 8 in a second shield 2C to be thermally connected to a cryogenic container main body 2. First stage 5 and second stage 7 of refrigeration device 1 are brought into surface contact in the atmosphere of vacuum region 9, respectively. Further, a liquid reservoir 2d filled with cryogenic fluid 10 is arranged inside the second shield 2C.

Further, a multilayer heat insulating material 11 is spread on the surfaces of each shield 2b, 2c and liquid reservoir 2d, respectively.

Next, the operation of the cryogenic container configured as above will be explained. Refrigeration equipment 1 has experienced a problem due to some unknown reason.
If its performance is no longer sufficient, the refrigeration device 1 will normally need to be heated. Before performing this heating, adjust the studs 3 that fix the refrigeration equipment to lengthen the span length.
By lifting the entire refrigeration device 1 from the vacuum container 2a, it becomes possible to cut off thermal contact with the boat, which is the joint between each stage 5.7 and the shields 2b, 2C.

This can prevent conduction, which is one form of heat intrusion. In addition, the bellows 4 used to connect the refrigeration device 1 and the cryogenic container 2 can be used as a common atmosphere without destroying the vacuum area 9, preventing convection and mitigating thermal contraction. It can also accommodate changes in length. In addition, the inflow and outflow of heat due to radiation can be reduced as much as possible by the multilayer heat insulating material 11 spread over the surfaces of each shield 2b, 2o1, each stage 5, 7, and liquid reservoir 2d.

Regarding thermal contact, the first . The boats 6.8 provided on the second stages 5 and 7 and the shields 2b and 2G have, for example, a tapered detachable thermal contact structure, and both surfaces are coated with indium or the like to ensure sufficiently good thermal contact. This allows the shield to be cooled without any problems.

Therefore, even if a problem occurs with the cooling of the shield, it is possible to heat only the refrigeration equipment without heating the entire cryogenic container, making it possible to immediately eliminate the problem with a highly flexible cryogenic container. can be obtained.

In the above embodiment, the thermal contact portion between the refrigeration device and the shield is formed into a tapered surface, but this contact portion is not limited to a tapered shape as long as it is detachable. Furthermore, other structures may be used as the structure for attaching and detaching the thermal contact portion using sudatsu as long as they comply with the spirit of the present invention.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to obtain a highly flexible cryogenic container that can correct the malfunctions of the refrigeration equipment without heating the entire cryogenic container.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a cryogenic container according to the present invention, and FIG. 2 is a longitudinal sectional view showing an example of a conventional cryogenic container. 1. Refrigeration device 2. Cryogenic container body 2a.
・・Vacuum container 2b・1st shield 2C・2nd
Shield 2d...Liquid reservoir 3...Stud
4 Bellows 5 - 1st stage 6 1st port 7... 2nd stage 8... 2nd boat 10...
Cryogenic fluid agent Patent attorney Nori Chika Hiroshi Mitsumata Figure 1

Claims (1)

[Claims] A cryogenic container body comprising a liquid reservoir for storing a cryogenic fluid, a shield disposed around the liquid reservoir, and a vacuum container covering the shield is brought into thermal contact with the shield to cool the shield. In the cryogenic container to which the device is attached, the cooling device is attached to the cryogenic container body using a bellows and a length-adjustable fastening member, and the connecting portion between the cooling device and the shield is made into a removable thermal contact structure. A cryogenic container characterized by: