JPS6060780A - Horizontal cryostat and manufacture thereof - Google Patents

Abstract

PURPOSE:To facilitate the winding operation of a multilayer thermal insulant by laminating the cryostat covered with the multilayer thermal insulant and the hollow cylindrical member surrounded by the multilayer thermal insulant. CONSTITUTION:A horizontal cryostat is composed of a superconducting magnet 1, liquid helium 2 for cooling the magnet 1, liquid helium container 3, an intermediate shield plate 4, a liquid nitrogen container 6 and a copper plate 7 for surrounding the shield plate 4. A multilayer thermal insulant 8 is wound around the outside of the container 6 and the copper plate 7. Next, the thin cylinder 21 to become a dummy on which a multilayer thermal insulant 22 is wound is prepared and this is attached to a flange 14 of a vacuum container body 9 and is combined with the end of the thermal insulant 8.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a horizontal cryostat and a method for manufacturing the same, and in particular, the present invention relates to a horizontal cryostat and a method for manufacturing the same. This article relates to a horizontal cryostat suitable for wrapping a multilayer insulation material around the outer periphery of a hollow cylindrical body and the cryostat, and a method for manufacturing the same.

[Background of the invention]

In conventional vertical cryostats, as a method to minimize the heat intrusion, a multilayer insulation shell of 20 to 30 layers is wrapped around the outer surface of the refrigerant container, refrigerant piping, equipment, etc. to be insulated.
It was wrapped in layers.

A horizontal cryostat, which has recently been attracting attention and has been applied to medical equipment, has a hollow cylinder that forms a room temperature space in the horizontal direction, that is, a bed space for clinical test patients, and a low-temperature thermostatic chamber around its outer periphery. A cryostat corresponding to the above is installed, and when wrapping a multilayer insulation material around the outer periphery of the hollow cylindrical body, not only that space is required, but also the assembly work is difficult.

Furthermore, when attaching a hollow cylindrical metal bar to the cryostat body, assembly work is difficult because the outer diameter of the hollow cylinder and the inner diameter of the flange of the cryostat body can only have a gap of 0.2 to 1 m+n. There was also an accident in which the hollow cylindrical rod collided with the flange and was damaged.

[Purpose of the invention]

The present invention was made in order to solve the problems of the prior art, and even if there is not enough space around the outer circumference of a hollow cylinder that forms a room-temperature space area in the horizontal direction, multilayer insulation can be applied to the outer circumference of the hollow cylinder. The object of the present invention is to provide a horizontal cryostat with excellent heat insulation performance that can be wrapped around materials and easily assembled, and a method for manufacturing the same.

[Summary of the invention]

The horizontal cryostat according to the present invention has a structure including a hollow cylindrical body that forms a room temperature space region in the horizontal direction, and a superelectric magnet, a cryogenic chamber for cryogenic fluid, a heat shielding means, etc. located on the outer periphery of the hollow cylindrical body. In a horizontal cryostat, the cryostat is covered with a TF multi-layer insulation material, the hollow cylindrical body is surrounded by a multi-layer insulation material, and the multi-layer insulation material of the cryostat and the multi-layer insulation material of the hollow cylindrical body are covered with a multi-layer insulation material. It is configured to overlap or join with a heat insulating material.

Further, the method for manufacturing a horizontal cryostat according to the present invention includes a hollow cylindrical body that forms a room temperature space region in the horizontal direction, a superelectric magnet, a cryostat for cryogenic fluid, and a heat shield located on the outer periphery of the hollow cylindrical body. A horizontal cryostat consists of a cryostat body with built-in cryostat equipped with equal parts, and a thin-walled cylinder wrapped with multi-layer insulation material, and a cryostat pre-covered with multi-layer insulation material is built into the thin-walled cylinder. After attaching it to the cryostat main body and superimposing or joining the multilayer insulation material of the thin cylinder with the multilayer insulation material of the cryostat, the thin cylinder is removed, and the hollow cylinder is inserted into the cryostat main body. Depends on how you put it on.

Additionally, the idea behind the invention is as follows.

Similar to the conventional vertical cryostat, in the horizontal cryostat as well, in order to improve the cryostat's insulation performance, a multilayer insulation material is used to reduce intrusion heat.

1. Consider a horizontal cryostat in which the inner diameter of the hollow cylinder, which is the horizontal room-temperature space region, is 1 m.

On the outer periphery of the hollow cylinder, a multilayer insulation material, a liquid nitrogen container, 7
8, 4.2 intermediate temperature history shield plate, liquid helium container immersed in super electric magnet', 78K.

4.2 Since the intermediate temperature shield plate and the multilayer insulation material are arranged concentrically, the outer diameter of the outside of the cryostat body is approximately 2 m, making the radiation heat transfer area extremely large.

Suppressing radiant heat by reducing the radiant heat transfer area is an effective way to improve the cryostat's insulation performance. I want to make the interval as small as possible. On the other hand, with a multilayer heat insulating layer, the heat insulating effect is poor if only a few layers of heat insulating material are wrapped around it, and it is necessary to wind around 20 to 30 layers. However, from the perspective of the cryostat equipment, it is necessary to minimize the amount of space needed to wrap the multilayer insulation material. Therefore, as a means to solve this problem, we prepared a dummy thin cylinder that was slightly thicker than the regular hollow cylinder wrapped with multilayer insulation material, and built this dummy into a cryostat IF that was covered with multilayer insulation material in advance. Attached to the cryostat main body, the thin-walled cylindrical multilayer insulation material,
After superimposing or discharging the multilayer insulation material of the cryostat, the dummy thin cylinder is removed, and the entire regular hollow cylinder is inserted into it to complete the assembly of the horizontal cryostat. This improves heat insulation performance and facilitates assembly.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be explained with reference to FIGS. 1 to 5.

FIG. 1 is a partial cross-sectional view of the main body of a horizontal cryostat according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a thin cylinder wrapped with a multilayer insulation material according to an embodiment of the present invention. FIG. 3 is a perspective view showing an example of the thin-walled cylinder, FIG. 4 is a perspective view showing a portion of the multilayer insulation material, and FIG. 5 is a completed assembly of a horizontal cryostat according to an embodiment of the present invention. It is a partially sectional view.

In FIG. 1, 1 is a superelectric magnet, 2 is liquid helium in which it is immersed and cooled, and 3Fi is a liquid helium container related to a cryogenic bath for cryogenic fluid.

Reference numeral 4 denotes an intermediate shield plate that is a heat shielding means that maintains an intermediate temperature between the liquid helium temperature and the liquid nitrogen temperature. 5 is liquid nitrogen, and 6 is a liquid nitrogen container related to the cryostat. 7
is a copper plate surrounding the intermediate shield plate 4. Super electric magnets) 1,9 bodies - Liumium container 4. Intermediate shield plate 4. i-body nitrogen container6. The copper plates 7 and the like have concentric cylindrical shapes to form a horizontal cryostand.

8 is a multilayer insulation system wrapped around the outside of the liquid nitrogen container 6 and the copper plate 7, in which a polymer film deposited with aluminum and a thin insulation layer such as a polyester net are alternately wrapped.

9 is a copper plate in a vacuum container, and is the super electric magnet mentioned above.

It constitutes a cryostat main body that houses a cryostat equipped with a cryogenic chamber for cryogenic fluid, heat shielding means, etc.

10. Liquid nitrogen container 6 on vacuum container copper plate 9? : A fixture for hanging, 11, a liquid helium container 3 on a liquid nitrogen container 6.
It is a fixture for hanging. Reference numeral 12 denotes a service port for introducing and discharging liquid helium and for taking out a single wire for supplying current to the superelectric magnet 1, and 13 is a boat for introducing and discharging liquid nitrogen.

14 is a flange of the vacuum container, that is, the cryostat main body, 15 is a gasket, 16 is a port, and 16a is a nut.

The procedure for assembling the hollow cylindrical body to the cryostat main body constructed in this way will be described next.

In FIG. 2, 21 is a dummy thin cylinder, which has a slightly larger outer diameter than a regular hollow cylinder. The material to be purchased is aluminum! If you use a lightweight material such as FRP or FRP, or if you use iron or stainless steel, which has a high electric capacity, make many holes in the cylinder to reduce the weight as shown in Figure 3. .

22 is a multilayer insulation material, as shown in Fig. 4, which is made of a thin insulation material such as a polyester film or nylon with a thickness of several microns to several tens of microns, aluminum evaporated on one or both sides, and nylon. This is a multilayer insulation material made by alternately wrapping nets 22b made of insulation material such as .

However, as the multilayer heat insulating material 22, although not particularly shown in the drawings, if it is an aluminum vapor deposited film with irregularities on the next surface, it may be wound in multiple layers.

As shown in FIG. 2, a dummy thin cylinder 21 is prepared in which a multilayer heat insulating material 22 that is slightly longer in the axial direction than the cylinder is wrapped in advance.

The dummy thin-walled cylinder 21 wrapped with the multilayer insulation material 22 is attached to the flange 14 of the vacuum vessel body 9, that is, the end of the multilayer insulation material 8, which is attached to the cryostat body and previously attached to cover the cryostand. Multi-layer insulation is achieved by wrapping the ends of the multi-layer insulation material 22 wrapped around the thin-walled cylinder 21 layer by layer, or by alternately overlapping the aluminum vapor-deposited sheets 22a and 22b in a single layer. Join the materials # warmly. In this way, heat intrusion is prevented and the insulation performance of the cryostat is improved.

In general, the insulation performance of multilayer insulation material increases as the spacing between layers increases, so it is especially important to avoid applying loads to the multilayer insulation material or wrapping it tightly during assembly. be. For this reason, the weight of the dummy thin cylinder is reduced, and when attaching the thin cylinder 21 wrapped with the multilayer insulation material 22 to the cryostat main body, consideration is given to prevent the multilayer insulation material 22 from being crushed by the weight of the cylinder. This is what is being done.

After the multilayer heat insulating materials 8 and 22 are superimposed or joined, pull out the dummy thin cylinder, or if there is no problem, insert all the regular hollow cylinders 20 as they are, attach them to the cryostat body, and seal them. Assembly is complete.

FIG. 5 shows the completed state.

Reference numeral 20 in FIG. 5 is a hollow cylindrical body inserted in its place after the dummy thin cylinder 21 was completely pulled out.

By doing this, you can not only easily wrap the multilayer insulation material even in a space with limited space, but also easily perform the most important end treatment when joining multilayer insulation, that is, overlapping the same layers. I can do it.

Next, an example of the invention that improves the workability of assembling the hollow cylindrical body 2° to the cryostat main body, and the original fifth example.
This will be explained with reference to the figures.

In Fig. 5, 14 is a flange, 15'! -1 packing, which is formed by the vacuum container body 9, the cylindrical body 2o, and the flange 14, and is used to maintain airtightness inside the vacuum container. Note that the pressure inside the vacuum container is 10-' Torr or less.

17a is fitted with a presser metal fitting for pressing and fixing the gasket 15'. Reference numeral 16 designates a bolt for fastening and fixing the presser fitting 15' to the flange 14.

20 is a hollow cylindrical body whose outer diameter at both ends is irregular. That is, in the example shown in FIG. 5, the cylindrical end on the right side of the figure becomes the flange portion of 202, and the left side becomes the ordinary cylinder 20b.

When assembling, the end of the hollow cylindrical body 20 with the smaller outer diameter 20b'5 is inserted into the main body of the fly male foot from the larger hole diameter part of the flange 14, so that the fit axiom is strict. The flange 14 and the hollow cylindrical body 20 can be easily inserted, improving work efficiency in assembly and disassembly.

Next, another embodiment of the present invention will be described with reference to FIG.

FIG. 6 is a schematic cross-sectional view showing a state in which a main body frame and a hollow cylinder are attached to a horizontal cryostat according to another embodiment of the present invention, and the equipment inside the main body is not shown. The parts with the same blue numbers as in Figure 5 are the same parts as the previous example.

In the figure, 17b is a presser metal fitting for pressing the gasket 15'i, and 18 is a presser metal fitting 17b-! It is a stopper to stop Z.

In the example shown in FIG. 5, the presser metal fitting 17a has the role of holding down the gasket 15' and also having the function of fixing it with the action of the bolt 16. However, in order to improve the airtightness and raise the vacuum armpit inside the vacuum container, in the example shown in FIG. It serves only one purpose.

Of course, if the material of the hollow cylindrical body 20' of Karuta is made of PRP, the end part 20' of the hollow cylindrical body (not shown) will be reduced in weight.
The sole surfaces of a and 20'b that come into contact with the flange of the mating cryostat main body, the presser fitting 17b, etc. are coated with metal such as stainless steel or aluminum. In this way, it is possible to improve the machining accuracy of the sole surface and improve vacuum insulation.

〔Effect of the invention〕

As described above, according to the present invention, even if there is not enough space on the outer periphery of the hollow cylindrical body that forms the normal temperature space region in the horizontal direction, the multilayer insulation material can be wrapped around the outer periphery of the hollow cylindrical body, Moreover, it is possible to provide a horizontal cryostat that can be easily assembled and has excellent heat insulation performance, and a method for manufacturing the same.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of the main body of a horizontal cryostat according to an embodiment of the present invention, and FIG. 2 is a sectional view of a thin cylinder wrapped with a multilayer insulation material according to an embodiment of the present invention. , 3rd
The figure is a perspective view showing an example of the thin-walled cylinder, FIG. 4 is a perspective view showing a part of the multilayer insulation material, and FIG. 5 is a part showing the assembly of a cryostat according to an embodiment of the present invention FIG. 6 is a schematic cross-sectional view showing a state in which the main body frame and hollow cylindrical body of a horizontal cryostat according to another embodiment of the present invention are attached. 1... Super electric magnet, 2... Liquid helium, 3
...Liquid helium container, 4...Intermediate temperature shield plate, 5...Liquid nitrogen, 6...Liquid nitrogen container, 7...
Copper plate, 8... Multilayer insulation material, 9... Vacuum container copper plate, 1
4...Flange, 15.15'...Putskin, 16
... Holt, 17a. 17b... Presser metal fitting, 18... Stopping metal fitting, 20.2
0'...Hollow cylindrical body, 21...Thin cylinder, 22...
・Multi-layer insulation material. Figure 1 %Z Figure Z I 3 Figure 4 2 Near”-2212- Figure 5

Claims (1)

[Claims] 1. A hollow cylindrical body forming a room temperature space region in the horizontal direction;
A horizontal cryostat, which is located on the outer periphery of the hollow cylindrical body and includes a cryostat body containing a superelectric magnet, a cryostat containing a cryogenic fluid, and a cryostat equipped with heat shielding means, etc., wherein the cryostat is covered with a multilayer insulation material, A horizontal cryostat, characterized in that the hollow cylindrical body is surrounded by a multilayer heat insulating material, and the multilayer heat insulating material of the cryostat and the multilayer heat insulating material of the hollow cylindrical body are constructed in a superimposed casing or joined together. 2. A horizontal cryostat according to claim 1, in which the hollow cylindrical body has different outer diameters at both ends. 3. The horizontal cryostat according to claim 1, wherein the hollow cylindrical body is made of FRP, and both or one end of the hollow cylinder body is coated with a metal on the surface that faces the flange of the Wagyu cryostat main body. 4. A cryostat body that includes a hollow cylinder that forms a room-temperature space in the horizontal direction, and a cryostat located on the outer periphery of the hollow cylinder that is equipped with a superelectric magnet, a cryogenic chamber for cryogenic fluid, heat shielding means, etc. In a horizontal cryostand, a thin cylinder wrapped with a multilayer insulation material is prepared, and the thin cylinder is attached to a cryostat body containing a cryostat covered with a laminated multilayer insulation material, and the multilayer insulation material of the thin cylinder is After overlapping or joining the insulation material B with the multilayer insulation material of the cryostat,
A method for manufacturing a horizontal cryostat, which comprises removing the thin cylinder, inserting the hollow cylinder therein, and attaching the hollow cylinder to the cryostat main body. 5. A method for manufacturing a horizontal cryostat according to claim 4, in which the hollow cylinder is inserted into the thin cylinder while the thin cylinder is attached to the cryostat main body.