JPS63263707A - Detachable radiant heat shielding refrigerating apparatus for superconductive magnet - Google Patents

Abstract

PURPOSE:To reduce the tensile load applied to the cylinder of a refrigerator and to contrive simplification of the assembling and disassembling operations of the title refrigerating device by a method wherein the functions of an intermediate flange and a heat conducting plate are combinedly performed, and the arrangement of the coupling bolts with which a cooling head is coupled to both of them, and the inserting part of a mounting and dismounting tool of the coupling bolts are matched. CONSTITUTION:The function of the heat-conducting plate on the medium temperature part is added to an intermediate flange 45, the function of the heat-conducting plate is added to a bottom plate 47, a medium-temperature cooling head 55 is bolted to the intermediate flange 45 at the position approximate to a cylinder, and a low-temperature cooling head 54 is bolted to the bottom plate 47 at the position approximate to the cylinder. Also, a coupling bolt and the inserting hole is match by providing the inserting holes 62 and 65 of the mounting and dismounting tool on the cover plate 42 and the intermediate flange 45 on the extended line of the axis of the coupling bolt, whereby the mounting and dismounting of the coupling bolts both on the medium-temperature side and the low-temperature side are made possible. As a result, the inside measurements of the expansion tube 46 between the bottom plate 47 and the intermediate flange 45 can be reduced, the load applied to the cylinder of a refrigerator when a housing container is brought into the state of high air pressure with a vacuum vessel 2 in a vacuum state, the structure of the device is simplified, and the assembling and disassembling works can also be simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a removable radiant heat shield refrigerator device with a superconducting magnet that can be attached and detached without breaking the vacuum of a cryostat.

[Conventional technology]

FIG. 6 is a partial cross-sectional view showing an example of a conventional superconducting magnet, and shows the cross-sectional structure of one side of the magnet formed in an annular shape surrounding the axis 11A2-2.

In the figure, 1 is a cryostat, and a liquid nitrogen container 5 is located between a helium container 6 containing a superconducting coil 7 immersed in liquid helium and a vacuum chamber 2 surrounding it.
It is equipped with a medium-temperature radiant heat shield 5 that is cooled to an absolute temperature of about 77 K by N, and a low-temperature radiant heat shield 4 disposed inside it.
The radiant heat from the vacuum container 2 side is absorbed by the medium and low temperature radiant heat shields 4 and 5, and the liquid helium contained in the helium container 5 is heated. Configured to reduce consumption. In such a conventional superconducting electromagnet, the outer diameter of the cryostat 1 is not large because it houses a liquid nitrogen container of 5N, and the maintenance work becomes complicated and requires replenishment of liquid helium and liquid nitrogen. This had the disadvantage of complicating the replenishment device.

Figure 7 is a side sectional view of the main parts of the improved conventional device;
A two-stage helium refrigerator 11 dedicated to cooling the medium-temperature and low-temperature radiant heat shields 5 and 4 is removably installed in a storage container 21 that partitions the vacuum chamber 2 of the cryostat 1. That is, the storage container 21 has an upper flange 26. which is airtightly connected to the vacuum container 2. Upper flange 23
and a lid plate 22 that is airtightly connected to the two-stage helium refrigerator 11 (hereinafter simply referred to as the refrigerator) and supports the refrigerator.
．． An intermediate flange 25 airtightly connected to the upper flange 26 via a telescopic tube 24. Telescopic tube 26 on intermediate flange 25
The vacuum chamber 2 is airtightly connected to the bottom plate 27 via the
An independent compartment is formed inside, and the inside of the storage container 21 can be exhausted through an exhaust pipe 39.

The refrigerator 11, which is airtightly connected and supported by the lid plate 22, is equipped with a low temperature cooling head 14 at the tip of a serial body of cylinders 12 and 13 (hereinafter referred to as a stepped cylinder), and a medium temperature cooling head 15 at the intermediate stepped part. Due to the helium refrigerant circulating between a circulation system consisting of a heat exchanger with a number of membranes built into the refrigerator and a compressor (not shown), the temperature reached by the low-temperature cooling head 14 is approximately 20 K, and the temperature reached by the medium-temperature cooling head 15 is approximately 20K. The temperature is cooled to a predetermined temperature in the range of 50°C to 80°C.

The medium temperature cooling head 15 is connected using four holes 32B to a cross-shaped heat conduction plate 32 which has an insertion hole 32A for the cylinder 16 in the center shown in FIG. 10, and the details of the heat conduction plate 32 are shown in FIG. four holes 32 in each of the intermediate flanges 25 shown;
connected by a bolt 64 passing through C and 25C,
By attaching a heat conduction lead 17 made of a flexible thermal conductor that connects the terminal hole 25D formed on the outer protrusion of the expandable tube of the intermediate flange and the medium-temperature radiant heat shield 5, the medium-temperature cooling head 15 and the medium-temperature radiant heat are connected. A heat conduction path is formed between the shield 5 and the shield 5. On the other hand, the low temperature cooling head 14 is bolted to the four screw holes 361 of the cross-shaped heat conduction plate 3 as shown in FIG. The heat conductive plate 66 is mounted in a direction 45 degrees different from the direction of the cross, and is fixed to the bottom plate 27 by bolts 38 passing through four holes 66F.
is connected to the low temperature radiant heat shield 4 by the heat conduction lead 18, thereby forming a heat conduction path on the low temperature side.

In addition, in order to enable attachment and detachment of the two-stage helium refrigerator 11 to and from the storage container 21 installed in advance in the vacuum chamber 2, a attachment/detachment tool 6 is provided for the eight equally spaced connecting bolts 34 and 38.
As shown in the plan view of the cover plate 22 in FIG. 8, eight insertion holes 65 are provided on the same circumference, and the middle 72 holes 65 are provided with a cross-shaped low-temperature side hole as shown in FIG. Heat conductive plate 6
A notch 25F is formed through which the 6 can pass. Therefore, when attempting to remove the refrigerator, the medium-temperature side coupling bolts 34 can be removed by vertically inserting the attachment/detachment tool 33 from the insertion ports 35 corresponding to the four holes 25C, which correspond to the notches 25F'. The low-temperature side coupling bolt 38 located below can be removed through the insertion port. Therefore, if the connecting bolts 37 between the cover plate 22 and the support flange 23 are removed, the refrigerator 1
The lid plate 22 and the heat conductive plates 32 and 66 can be pulled out from the storage container 21 in a state that they are combined with each other.

In the above-mentioned improved conventional device, the radiant heat shields 5 and 4, which have two layers of medium and low temperatures, are cooled to a predetermined temperature, for example, 80 and 20 K, by the refrigerator, so there is no need to provide the liquid nitrogen container 5N in the cryostat 1. This has the advantage that the outer diameter of the cryostat is reduced and maintenance becomes easier. Since the refrigerator is housed in the storage container 21 and separated from the high-vacuum section within the vacuum chamber 2, the vacuum chamber 2 can be evacuated in the event of a malfunction of the refrigerator! ! If the refrigerator becomes removable and humid air enters the vacuum chamber, the heat insulating material (not shown) inside the vacuum chamber absorbs moisture.
This avoids the problem that it takes a very long time to remove this moisture and restore high vacuum again.

[Problem that the invention seeks to solve]

In the refrigerator device with the improved removable radiant heat shield described above, when removing the refrigerator 11 by returning the storage container 21 to atmospheric pressure while maintaining the high vacuum in the vacuum chamber 2, the storage container 21 From the atmospheric pressure side to 1 to 9f/Ctd
When an external pressure of 9 is applied, the bottom plate 27 becomes P−πD”/414f
(D is the inner diameter of the extensible tube) The extensible tube is pulled in the direction of stretching by a huge load. The expansion tubes 24 and 26 are equipped with connecting bolts to suppress excess expansion, so the expansion tubes will not be damaged, but most of the above load is applied to the cylinders 13 and 12 of the refrigerator 11 due to This may lead to damage to the thin cylinder 13 on the low temperature side.

In particular, because the main focus of the configuration is to make it easier to attach and detach the refrigerator by vertically inserting the coupling bolt attachment/detachment tool, the inner diameter of the expandable tube is large, and the inner diameter is 2.
There was a drawback that the load P, which increases in proportion to the multiplication factor, becomes significantly large. Also, on the medium temperature side.

The structure becomes complicated, as it requires a number of tool insertion slots for all the coupling bolts on the low-temperature side, and heat conductive plates are required on each of the medium-temperature side and low-temperature side. The disadvantage was that the disassembly work was complicated.

This invention purports to reduce the load applied to the refrigerator and facilitate assembly and disassembly work by streamlining the structure of the device.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention includes a storage container that partitions the inside of the vacuum container of a cryostat, and a stepped cylinder that is detachably supported by the storage container and has a medium-temperature cooling head in the middle part, and a tip part. 2 with low temperature cooling head in
and a staged helium refrigerator for cooling a medium-temperature radiant heat shield and a low-temperature radiant heat shield enclosed in the vacuum container so as to double-enclose a helium container containing a superconducting coil to a predetermined temperature, respectively, wherein the vacuum container a lid plate airtightly connected to the lid plate through a telescopic tube, a medium temperature heat conduction plate which is thermally conductively connected to the medium temperature radiant heat shield and has a hanging hole in the center thereof through which the low temperature cooling head passes; a storage container comprising an intermediate flange that also serves as a low-temperature heat conduction plate, and a bottom plate that also serves as a low-temperature heat conduction plate that is airtightly connected to the intermediate flange via a telescopic tube having an inner diameter smaller than the expandable tube and thermally conductively connected to the low-temperature radiant heat shield; A medium-temperature cooling head is airtightly connected and supported to the center of the lid plate and inserted into the storage container, and a medium-temperature cooling head is connected to the intermediate flange, and a low-temperature cooling head is connected to the trust plate at a predetermined angle toward the axis of the stepped cylinder. The two-stage helium refrigerator is held and connected by the same number of connecting bolts disposed in the same angular area in the circumferential direction, and the connecting bolt is connected to the cover plate and the intermediate flange in the angular area where the connecting bolts are provided, respectively. and an insertion hole for an attachment/detachment tool for the coupling bolt formed in the extending direction of the axis of the bolt.

[Effect]

In the configuration of this invention, the intermediate flange has the function of a heat conduction plate on the medium temperature side, and the bottom plate has the function of a heat conduction plate on the low temperature side,
The medium-temperature cooling head is bolted to the intermediate flange at a position close to the cylinder, and the low-temperature cooling head is bolted to the bottom plate at a position close to the cylinder.This reduces the required area of the bottom plate, in other words, reduces the area between the bottom plate and the intermediate flange. The inner diameter of the expandable tube can be reduced, and the load applied to the cylinder of the refrigerator is reduced when the storage container is brought to atmospheric pressure while the vacuum chamber is kept in vacuum. In addition, the number and circumferential position of the connecting bolts on the medium-temperature side and the low-temperature side are equal to each other, and they are inclined toward the axis of the cylinder, and the attachment/detachment tool is inserted into the cover plate and intermediate flange on the extension of the axis of the connecting bolts. Since the coupling bolts and the insertion holes are aligned so that holes are provided, it is possible to attach and detach the coupling bolts on both the medium temperature side and the low temperature side, which are placed in the same angular area, by inserting the attachment/detachment tool diagonally from the insertion hole. Furthermore, by reducing the number of insertion holes and eliminating heat conductive plates, the structure can be simplified and assembly and disassembly work can be made easier.

[Practical]

The present invention will be explained below based on examples.

FIG. 1 is a side sectional view showing an embodiment of the device of the present invention.
Detailed explanations will be omitted by assigning the same reference numerals to the same parts as in the prior art. In the figure, the storage container 541 is
A lid plate 42 is airtightly connected to the vacuum chamber 2, an intermediate flange 45 which also serves as a medium temperature heat conduction plate is airtightly connected to the vacuum chamber 2 via a telescopic tube 44, and an airtight airtight connection is provided through a telescopic tube 46 having an inner diameter smaller than that of the telescopic tube 44. The intermediate flange 45 and the bottom plate 47, which also serves as a low-temperature heat conductive plate, are connected to the medium-temperature radiant heat shield 5 and the low-temperature radiant heat shield 4 through flexible heat conductive boards 17 and 18, respectively. Heat conductively coupled. The refrigerator 11 is hermetically bolted to the center of the lid plate 42, and the stepped cylinders 12 and 13 are inserted into the storage container 41, and the medium temperature cooling head 55 is thermally conductively connected to the intermediate flange by a connecting bolt 57, and the low temperature cooling head 54 is thermally conductively connected to the bottom plate 54 by a connecting bolt 58, thereby forming heat conduction paths on the medium temperature side and the low temperature side.

Fig. 2 is a plan view of the lid plate in the embodiment device, Fig. 3 is a plan view of the medium temperature cooling head, Fig. 4 is a plan view of the intermediate flange, and Fig. 5 is a plan view of the low temperature cooling head. The illustration is such that the positional relationships in the circumferential direction correspond to each other. The low temperature cooling head 54 is formed in a cross shape as shown in FIG. 5, and the medium temperature cooling head 55 is formed in a circle as shown in FIG. They are connected to the stepped cylinder of the refrigerator 11 so that their angular regions substantially coincide with each other.

Further, the intermediate flange 45 has a cross-shaped hole 45B through which the low-temperature cooling head 54 can pass.
Therefore, the refrigerator 11 is rotated 45 inches in the circumferential direction and inserted into the storage container 41, and after the low-temperature cooling head 54 passes through the hole 45B of the intermediate flange, the refrigerator 11 is rotated 45 inches in the circumferential direction. °If you rotate it in the opposite direction, the refrigerator will be set in the normal position in the storage container.

Further, in the connected state, each of the four connecting bolts 57 and 58 has an axis extending in the direction of the center p of the insertion hole 62 of the attachment/detachment tool 63 formed in the cover plate 42 shown in FIG.
The cooling head is mounted obliquely toward the axis of the stepped cylinder so as to coincide with the angle of inclination, and the inclination angle is maintained by the inclination angle of the upper surface of the cooling head and the inclination angle of the bolt holes 55A, 45A, 54A, etc. Also, the coupling bolt 58 on the low temperature cooling head side
As shown in FIG. 4, an insertion hole 65 for an attachment/detachment tool is formed in the intermediate flange 45 on the line connecting the points P and 45 in the same angular direction as the coupling screw hole 45A of the coupling bolt 57. Therefore, the work of attaching and detaching the four coupling bolts 57 and 58 of the refrigerator 11 set in the fixed position of the storage container 41 is as follows.
This can be easily done by inserting the attachment/detachment tool 33 holding the bolt through the four insertion holes 62 along the two axes.

In the apparatus of this embodiment configured as described above, the inner diameter of the telescopic tube 46 between the intermediate flange and the bottom plate can be reduced to about 60% of that of the conventional apparatus. This means that the tensile load of 1000#f applied to the cylinder 16 in the conventional device is 56OJI.
This means that fK can be reduced, thereby avoiding damage to the refrigerator. In addition, the number of insertion holes for the attachment/detachment tool is reduced to half that of the conventional device, and the number of parts is reduced because the intermediate flange and bottom plate also serve as the heat conductive plate in the conventional device, which reduces the structure of the device. This simplifies assembly and disassembly work.

〔Effect of the invention〕

As described above, this invention allows the intermediate flange and bottom plate of a storage container that airtightly partitions the inside of a vacuum chamber to function as a heat conductive plate in a conventional device, and also connects the cooling head of a refrigerator to the intermediate flange and bottom plate. The structure is designed to be rationalized by relative alignment between the mounting structure arrangement of the coupling bolt and the insertion part of the coupling bolt attachment/detachment tool.

As a result, the inner diameter of the expansion tube on the bottom plate side is 60 mm compared to that of the conventional device.
%, and the tensile load applied to the refrigerator cylinder when the storage container is brought to atmospheric pressure is reduced to approximately % of that of conventional equipment, so the work of removing the refrigerator can be reduced while maintaining the high vacuum state of the vacuum chamber. It is possible to provide a refrigerating machine with detachable superconducting magnets and a radiant heat shield that can be used without causing damage to the machine.

In addition, the structure is simplified, making it easier to assemble and disassemble the device, and there are advantages in improving economic efficiency.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an embodiment of the device of the present invention, FIGS. 2, 6, 4, and 5 are plan views showing different main parts of the embodiment device, and FIG. FIG. 7 is a side sectional view of the main parts of a conventional superconducting magnet. FIG. 7 is a side sectional view of an improved conventional device. FIGS. 8, 9, 10, and 11 are improved conventional devices. FIG. 1... Cryostat, 2... Vacuum chamber, 6...
Helium container, 4... Low temperature radiant heat shield, 5...
Medium temperature radiant heat shield, 6...liquid helium, 7...
Superconducting coil, 11...Two-stage helium refrigerator, 12
, 13... Stepped cylinder, 14, 54... Low temperature cooling opening head, 15.55... Medium temperature cooling head, 21.41
... Storage container, 22.42 ... Lid plate, 24,44.
26... Telescopic pipe, 46... Telescopic pipe (shrinkage), 25.
45... Intermediate flange, 27, 47... Bottom plate, 54
, 57... Connection bolt (medium temperature side), 38.58...
Connection bolt (lower figure 1 葡7 area)

Claims (1)

[Scope of Claims] 1) A storage container that partitions the inside of the vacuum container of the cryostat, and a two-stage stepped cylinder that is detachably supported by the storage container and has a medium-temperature cooling head in the middle part and a low-temperature cooling head in the tip part. and a helium refrigerator for cooling a medium-temperature radiant heat shield and a low-temperature radiant heat shield enclosed in the vacuum container to a predetermined temperature, respectively, so as to double surround a helium container housing a superconducting coil, a lid plate that is airtightly connected to the lid plate; a medium temperature heat conduction plate that is airtightly connected to the lid plate via an expansion tube, is heat conductively connected to the medium temperature radiant heat shield, and has a hole in the center thereof through which the low temperature cooling head can pass; Intermediate flange that also serves as
and a storage container consisting of a bottom plate which also serves as a low temperature heat conduction plate, which is airtightly connected to the intermediate flange via a telescopic tube having an inner diameter smaller than that of the retractable tube, and which is thermally conductively connected to the low temperature radiant heat shield; A medium temperature cooling head is connected and supported in an airtight manner and inserted into the storage container, and a medium temperature cooling head is attached to the intermediate flange, and a low temperature cooling head is attached to the bottom plate at a predetermined angle toward the axis of the stepped cylinder and in the same angular area in the circumferential direction. The two-stage helium refrigerator is connected to the two-stage helium refrigerator by the same number of connecting bolts, and the connecting bolts are formed in the direction of extension of the axis of the connecting bolts in the angular region of the connecting bolts on each of the lid plate and the intermediate flange. and an insertion hole for an attachment/detachment tool for the coupling bolt. 2) In the product described in claim 1, the temperature reached by the low-temperature cooling head of the two-stage helium refrigerator is approximately 20
K, a superconducting magnet detachable radiant heat shield refrigerator device characterized in that a medium temperature cooling head reaches a temperature of 50K to 80K.