JP2643639B2 - Cryogenic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cryogenic device for accommodating, for example, superconducting magnet windings, and more particularly to a cryogenic container in a vacuum container and a support structure for supporting a radiant heat shield.

[0002]

2. Description of the Related Art FIG. 4 is a cross-sectional view showing a support mechanism of a superconducting magnet wound container which is a kind of a cryogenic device disclosed in Japanese Patent Application Laid-Open No. 60-206007. In the drawing, reference numeral 1 denotes a cryogenic vessel which is cooled and held at a cryogenic temperature, 2 is a vacuum vessel for accommodating the cryogenic vessel 1 therein, and 3a is arranged so as to cover an outer wall of the cryogenic vessel 1. Low temperature radiation heat shield,
3b is a high-temperature radiation heat shield arranged so as to cover the outside of the low-temperature radiation heat shield 3a. Reference numeral 4 denotes a suspension mechanism for suspending and supporting the cryogenic container 1, the low-temperature radiant heat shield 3a and the high-temperature radiant heat shield 3b from the vacuum container 2, and 12 denotes a variable length for holding the positions of the vacuum container 2 and the cryogenic container 1. It is a compression strut. FIG. 5 is an enlarged sectional view showing the configuration of the compression column 12. As shown in FIG. In the figure, reference numeral 12a denotes a first pipe column firmly fixed to the low-temperature radiant heat shield 3a and the high-temperature radiant heat shield 3b, 12b denotes a second tube column partially fitted to the first tube column 12a, and 12c denotes a second tube column. The compression column 12 is formed by a spring mounted to press the second tube column 12b toward the cryogenic container 1.

Next, the operation will be described. Cryogenic container 1
The suspension mechanism 4 suspends the vacuum vessel 2 from the vacuum vessel 2 and fixes the position in the vertical direction. On the other hand, in the horizontal direction, the compression column 12 is supported by pulling the space between the cryogenic vessel 1 and the vacuum vessel 2 by the spring 12c. Low temperature radiation heat shield
The distance between the 3a, the high-temperature radiant heat shield 3b, and the vacuum vessel 2 is fixed because each is firmly fixed to the first pipe column 12a. Next, the behavior of each component before and after cooling is as follows. Before cooling, the temperature of each component is the same as that of the vacuum vessel 2,
The cryogenic vessel 1, the low-temperature radiation heat shield 3a, and the high-temperature radiation heat shield 3b are fixed at predetermined positions by adjusting the suspension mechanism 4 and the compression column 12.

On the other hand, the behavior of each component in the state after cooling is such that the vacuum vessel 2 is constant at room temperature,
3b, the low-temperature radiation heat shield 3a, and the cryogenic vessel 1 have lower temperatures in this order. Therefore, since the temperature of each component is different, a difference occurs in the amount of heat shrinkage. Furthermore, the suspension mechanism 4 and the compression column 12 also have different temperatures at the portions in contact with the vacuum vessel 2, the high-temperature radiant heat shield 3b, the low-temperature radiant heat shield 3a, and the cryogenic vessel 1, so that a temperature gradient occurs and uneven heat shrinkage occurs. Will occur. In the configuration of FIG. 3, the cryogenic container 1 moves upward with respect to the vacuum container 2 due to the heat shrinkage of the suspension mechanism 4. In addition, since the cryogenic container 1 itself also undergoes heat shrinkage, a compression strut
The distance between the vacuum vessel 2 and the cryogenic vessel 1 at the mounting portion 18 is further increased. In response to this displacement, the compression column 12 pushes the second pipe column 12b by the action of the spring 12c, and its entire length is extended to absorb the displacement. However, the high-temperature radiant heat shield 3b and the low-temperature radiant heat shield 3a are firmly fixed by the suspension mechanism 4 and the first pipe column 12a of the compression column 12, so that the suspension mechanism 4 and the compression column 12 are heated by both radiation heat shields. It must have a sufficient cross-sectional area to support the stress due to differential shrinkage by shearing and pulling.

[0005]

Since the conventional cryogenic device is configured as described above, the normal temperature portion and the cryogenic portion are connected via a radiant heat shield support rod, and heat intrusion due to heat conduction is prevented. is there. Also, since the deformation due to heat shrinkage is absorbed by the spring in the support rod, the structure of the support structure itself becomes complicated and the number of parts increases, and the support structure itself receives thermal stress due to heat shrinkage of the radiant heat shield, It is necessary to increase the number of the support structures by increasing the size of the component parts or shortening the mounting interval of the support structures, which causes problems such as an increase in heat penetration into the cryogenic part due to heat conduction.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and eliminates heat intrusion from a normal temperature portion to a cryogenic portion by heat conduction through a radiant heat shield support structure portion with a simple configuration. It is another object of the present invention to provide a cryogenic device having a support structure capable of easily absorbing the heat shrinkage of the radiation heat shield.

[0007]

According to the cryogenic apparatus of the present invention, a radiant heat shield provided so as to cover the cryogenic vessel housed in the vacuum vessel has an upper surface opened to cover the outer wall side of the cryogenic vessel. A low-temperature radiation heat shield, and at least two layers of a high-temperature radiation heat shield arranged so as to open the upper surface and cover the outer wall of the low-temperature radiation heat shield, and are disposed over the openings having respective radiation heat shields and voids. Suspension means formed of a radiant heat shield lid and supporting the radiant heat shield and the cryogenic vessel in the vacuum vessel from the inner wall of the upper surface of the vacuum vessel, and suspending and supporting each of the radiant heat shield lid and the cryogenic vessel with a gap. And, a plurality is arranged around by engaging with each radiant heat shield,
Horizontal support means for positioning between the respective radiant heat shields, and an end protruding from the high-temperature radiant heat shield side abutting on the inner wall of the vacuum vessel to position the two radiant heat shields in a horizontal direction, and engaging with the respective radiant heat shields to form a bottom portion. And vertical support means for positioning between the respective radiant heat shields, and having an end protruding from the high-temperature radiant heat shield side in contact with the bottom inner wall of the vacuum vessel to position the respective radiant heat shields in the vertical direction. Things.

[0008]

In the cryogenic apparatus according to the present invention, the low-temperature radiation heat shield is self-supporting and has no support for the cryogenic vessel, so that heat penetration from the radiant heat shield to the cryogenic vessel is eliminated. The difference in the amount of thermal contraction of each layer of the radiant heat shield is absorbed by sliding the change in length of each layer of the radiant heat shield in a fixed direction in the support structure portion and deforming the radiant heat shield itself within elastic deformation. Also, the difference in the amount of thermal contraction between the vacuum vessel and the radiant heat shield is absorbed by supporting the radiant heat shield and sliding the tip of the support structure in contact with the vacuum vessel, so that the force acting on the support structure itself can be reduced. .

[0009]

[Embodiment 1] FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is an enlarged sectional view of the horizontal supporting means in FIG. 1, and FIGS. 3a and 3b are enlarged sectional views of the vertical supporting means in FIG. In the figure, reference numerals 1 and 2 are the same as those of the conventional configuration, and the description thereof is omitted. 5 is open at the top
5b Shielding part arranged to cover cryogenic vessel 1 and outer wall
5a, a low-temperature radiant heat shield comprising a reinforcing plate 5c for reinforcing this and a plurality of screw seats 5d fixed to the bottom surface of the shielding portion, and 6 is arranged so that the upper surface is opened 6b to cover the outer wall of the low-temperature radiant heat shield 5. A high-temperature radiant heat shield comprising a shielding portion 6a and a reinforcing plate 6c for reinforcing the same, 10 is a low-temperature radiant heat shield, a radiant heat shield lid provided with a gap and covering the opening 5b, and 11 is a low-temperature radiant heat shield 5 and radiant heat. Shield lid
One of the cooling pipes 7 provided in contact with 10 is a holding rod 7a, one of which is held by a reinforcing plate 5c of the low-temperature radiant heat shield 5 with a washer 7e and a nut 7c and the other end of which contacts the high-temperature radiant heat shield 6. The other end and one end of the holding rod 7a are screwed into the washer 7f and the nut.
7d, a horizontal support means comprising a high-temperature radiant heat shield 6 and an adjusting rod 7b having the other end in contact with the inner wall of the vacuum vessel 2, one of which is screwed to a screw seat 5d on the center side and the other is high-temperature A washer 8c, which is inserted below the radiant heat shield 6 with a gap and has an abutment with the inner wall of the vacuum vessel 2 and is mounted below the high-temperature radiant heat shield 6 and a retaining ring 8d for holding the washer, is provided. A supporting member 8a for determining the vertical position of 5 and 6 and one end is screwed into the screw seat 5d on the end side and the other is inserted with a gap with the high-temperature radiant heat shield 6 and the end comes into contact with the inner wall of the vacuum vessel 2. A vertical support means 9 comprising a support rod 8e is suspended from the upper inner wall of the vacuum vessel 2 and is provided below the radiant heat shield lid 10 and the cryogenic vessel 1 below.
Are suspension means for supporting each of them with a gap.

Next, the operation of the present invention will be described. First, the method of assembling the cryogenic device having the above-mentioned supporting means is as follows. The low-temperature radiant heat shield 5 includes the holding rod 7a of the horizontal supporting means 7 and the supporting member 8a and the supporting rod 8e of the vertical supporting means 8. It is attached and inserted into the high-temperature radiation heat shield 6. After the insertion, both radiant heat shields and the vacuum vessel 2 are positioned in the horizontal direction by the adjusting rod 7b, and the adjusting rod is adjusted by the nut 7d.
7b is fixed, and the high-temperature radiant heat shield is positioned vertically by the washer 8c and the retaining ring 8d, so that the supporting structure component can be easily mounted from outside the radiant heat shield. The support rod 8e does not support the high-temperature radiation heat shield 6, but bears part of the vertical support of the high-temperature radiation heat shield 6 by the horizontal support means 7 via the low-temperature radiation heat shield 5.

Next, the operation during cooling will be described. The low-temperature radiation heat shield 5 is cooled by a cryogen flowing in the cooling pipe 10. The high-temperature radiation heat shield 6 is a low-temperature radiation heat shield 5
The temperature at the balance point between the radiant heat from the vacuum vessel and the radiant heat from the vacuum vessel 2 is taken. This causes a difference in the amount of thermal contraction between the two radiant heat shields. There are two directions of heat shrinkage, a horizontal direction and a vertical direction. For horizontal heat shrinkage, the horizontal support means 7 part completely fixes both radiant heat shields,
At this position, a strengthening plate 5c is provided on the side of the low-temperature radiation heat shield 5 and the strengthening plate 6c of the high-temperature radiation heat shield 6 avoids this position so that the high-temperature radiation heat shield 6 can be easily deformed and absorb heat shrinkage.

The inner support member 8a of the vertical support means 8 supports the high-temperature radiation heat shield 6 in the vertical direction but does not fix it in the horizontal direction, so that it can slide in the horizontal direction to absorb the heat shrinkage. . At the inner support rod 8e of the vertical support means 8, the high-temperature radiant heat shield 6 is not restrained at all, and there is no problem. Next, with respect to the heat shrinkage in the vertical direction, since the high temperature radiation heat shield 6 is not restrained by the support rod 8e of the vertical direction support means 8, the heat shrinkage of the low temperature radiation heat shield 5 is passed through the horizontal support means 7. It is absorbed by pushing down the lower plate of the high-temperature radiation heat shield 6.
Further, since the radiant heat shield support means and the cryogenic vessel support means are separated from each other, heat penetration due to heat conduction into the cryogenic vessel 1 is eliminated, and the cryogenic vessel can be removed without removing the radiant heat shield from the vacuum vessel 2 during disassembly.

Embodiment 2 FIG. The first embodiment is characterized in that the heat shrinkage difference is absorbed by bending the shielding portion 6a of the high-temperature radiation heat shield 6. However, when both radiation heat shields have high rigidity and cannot be absorbed by bending, there are a plurality of peripheral heat shields. Only one of the horizontal support means 7 is held by 7a to 7e, and the other parts are all 8a to 8e of the radiation support means 8.
It has the same structure as 8d and can slide and absorb in the circumferential direction. The heat shrinkage in the vertical direction is also high
The lower plate can be slid and absorbed by the horizontal support means 7 without bending.

Embodiment 3 FIG. In the first embodiment, the two-layer shield is described. However, the vertical support means has the same structure as the horizontal support means 7, so that it can be used for a shield having two or more layers.

Embodiment 4 FIG. Further, when the high-temperature radiant heat shield of the above embodiment is made of a highly magnetically permeable material such as permalloy, for example, in the vicinity of a vacuum vessel, for example, when a device that is adversely affected by a magnetic field such as a motor of a small refrigerator is installed, When storing things that are adversely affected by a magnetic field of the order of terrestrial magnetism such as a Hall element inside the vacuum vessel,
It can also serve as a function of magnetically shielding between the inside and the outside of the vacuum vessel, so that there is no need to separately provide a magnetic shield, and an effect of obtaining effective performance with a simple configuration can be obtained.

[0016]

As described above, according to the present invention, the radiant heat shield provided so as to cover the cryogenic container housed in the vacuum container is arranged so as to open the upper surface and cover the outer wall side of the cryogenic container. A low-temperature radiant heat shield, at least two layers of a high-temperature radiant heat shield arranged so as to open the upper surface and cover the outer wall of the low-temperature radiant heat shield, and a radiant heat shield lid arranged so as to cover the respective radiant heat shields and the openings having voids. A suspension element formed of a supporting element for holding the radiant heat shield and the cryogenic vessel in the vacuum vessel, suspending from the inner wall of the upper surface of the vacuum vessel, and suspending and supporting each of the radiant heat shield lid and the cryogenic vessel with a gap, A plurality of radiant heat shields are engaged with each other and are arranged around the radiant heat shields to position between the radiant heat shields and protrude from the high-temperature radiant heat shield side. Horizontal support means whose end abuts against the inner wall of the vacuum vessel and positions both radiant heat shields in the horizontal direction, and is disposed on the bottom in engagement with the respective radiant heat shields, positions between the respective radiant heat shields, and sets the temperature between Since the end protruding from the radiant heat shield side abuts against the bottom inner wall of the vacuum vessel and is configured with vertical support means for setting the position of each radiant heat shield in the vertical direction, it is possible to change from a normal temperature part to a cryogenic part with a simple configuration. Thus, there is an effect that a cryogenic device having a support structure capable of easily absorbing the heat shrinkage of the radiant heat shield while eliminating heat intrusion due to heat conduction through the radiant heat shield support structure can be obtained. Further, since one of the multilayer radiant heat shields also serves as a magnetic shield, a function of magnetically shutting off the inside and the outside of the vacuum vessel with a simple structure can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of the horizontal support means in FIG. 1 of the present invention.

FIG. 3 is an enlarged sectional view of the vertical support means in FIG. 1 of the present invention.

FIG. 4 is a sectional view showing a support mechanism in a conventional cryogenic device.

FIG. 5 is an enlarged sectional view showing a configuration of a compression column in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cryogenic container 2 Vacuum container 5 Low temperature radiant heat shield 6 High temperature radiant heat shield 7 Horizontal support means 8 Vertical support means 9 Hanging means 10 Radiant heat shield lid

Claims (2)

(57) [Claims] 1. A cryogenic container cooled to a cryogenic temperature by a cryogen, a vacuum container forming a vacuum heat insulating tank for accommodating the cryogenic container, and a cryogenic container provided between the two containers so as to cover the cryogenic container. In a cryogenic device comprising a radiant heat shield for thermal insulation, and a support element for holding the radiant heat shield and the cryogenic container in the vacuum vessel with a gap therebetween, the radiant heat shield has an open upper surface and the cryogenic container is provided. A low-temperature radiant heat shield disposed so as to cover the outer wall side, at least two layers of a high-temperature radiant heat shield disposed so as to open the upper surface and cover the outer wall of the low-temperature radiant heat shield, and each of the radiant heat shield and the air gap. Formed by a radiant heat shield lid disposed over the opening,
The support element is suspended from the inner wall of the upper surface of the vacuum vessel, suspending means for suspending and supporting each of the radiant heat shield lid and the cryogenic vessel with an air gap, and a plurality of suspending means arranged around the radiant heat shield in engagement with the respective radiant heat shields. Positioning between the respective radiant heat shields, and horizontal support means for positioning the ends of the radiant heat shields in the horizontal direction by contacting the inner wall of the vacuum vessel with an end projecting from the high-temperature radiant heat shield side, It is arranged on the bottom in engagement with the radiant heat shield, positioned between the radiant heat shields, and the end protruding from the high-temperature radiant heat shield side is in contact with the bottom inner wall of the vacuum vessel in the vertical direction of each of the radiant heat shields. And a vertical support means for positioning the cryogenic device. 2. The cryogenic device according to claim 1, wherein one of the plurality of radiant heat shields also serves as a magnetic shield.