JPH0511643B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an immersion cooling type superconducting device,
In particular, the present invention relates to a superconducting device using a horizontal cryostat used in a nuclear magnetic resonance tomography device (NMR-CT scanner).

[Conventional technology]

Conventionally, this type of superconducting device has generally been used in a fixed manner, and has not been considered to be used while being moved or transported. Therefore, the support structure for the helium container inside the vacuum insulated container is currently made with consideration only to mechanical strength for installation and operation inside the building and prevention of heat intrusion from the outside. A conventional example of a support structure for a superconducting device is JP-A-60-147105.
No., JP-A-60-147104, JP-A-60-147106
The number etc. are known.

[Problem that the invention seeks to solve]

However, recently, in order to make effective use of NMR-CT, there is a concept of moving one NMR-CT to various locations. Therefore, it is highly questionable whether the conventional support structure can sufficiently withstand vibrations and shock loads when being moved or transported while being filled with refrigerant (helium).

As described above, in the past, there was no idea or need to move a superconducting device while cooling it, so if the superconducting coil was transported as it is, there is a risk of fatal damage to the superconducting coil.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a superconducting device having a support structure that has sufficient support strength when moving while being cooled and can prevent heat from entering.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention includes a cylindrical coolant container connected to the cylindrical insulating vacuum container at its axial center in a cylindrical insulating vacuum container placed with its axial direction horizontally arranged. , a helium container in which a superconducting coil and liquid helium are stored is disposed on the circumferential side of the cylindrical coolant container via an arm-shaped mounting seat and a heat insulating support member extending from both axial ends of the coolant container, respectively; In the superelectric device which is supported and fixed, the support points of the helium container by the heat insulating support are provided at a ratio of 1 in the vertical direction and 2 at symmetrical positions in the horizontal direction when viewed in a radial cross section of the helium container. It is something to do.

[Effect]

The load acting on the helium container support during transportation varies depending on the conditions during transportation, but is approximately 3 times and 1.5 times the static load in the vertical and lateral directions, respectively. That is, it is ideal if the load-bearing ratio of the support is 2:1. On the other hand, the characteristics of multiple cylindrical supports are:
In the longitudinal direction and the direction perpendicular to the longitudinal direction, both load capacity and rigidity are much greater in the longitudinal direction. Therefore, it is more effective to receive the load in the longitudinal direction, and in this case, the longitudinal direction is arranged in a ratio of 2:1 in the longitudinal direction to the horizontal direction, and the supporting structure is made to withstand transport with a minimum amount of heat penetration.

When supporting a helium container within a limited space within a vacuum insulated container, even if the amount of heat intrusion per support is constant, it is necessary to obtain sufficient support strength against vibrations and shocks during movement. teeth,
The number of support points must be increased, and therefore the number of heat-insulating supports must be used within the limits necessary to maintain the above-mentioned support strength. In other words, an increase in support strength means an increase in the amount of heat penetration. From this point of view, the present invention is designed to ensure optimal support strength against horizontal and vertical vibrations during movement while minimizing heat infiltration.

〔Example〕

Next, embodiments of the present invention will be described based on the drawings.

First, FIG. 2 shows the entire superconducting device according to the present invention. This superconducting device is of a horizontal type, so the cylindrical insulating vacuum container 7 is placed with its axial direction horizontal. A cylindrical nitrogen container 1 is housed within the vacuum container 7. This nitrogen container 1 is supported at four locations (top, bottom, left and right) in its axially central portion, and is housed in a suspended state.
(See Figure 3). Furthermore, a helium container 2 is also housed in a suspended state on the inner peripheral side of the nitrogen container 1. That is, the helium container 2 is supported via an L-shaped arm-shaped mounting seat 5 extending inward from both axial ends of the nitrogen container 1 and heat insulating supports 3a and 3b. As shown in FIG. 1, the support points are provided at a total of three places in the radial cross section of the helium container 2, one place 3a at the top in the vertical direction and two places 3a and 3b at symmetrical positions in the horizontal direction, at a ratio of 1:2. It is being The helium container 2 is filled with liquid helium 8 and a superconducting coil 9.

The heat insulating supports 3a and 3b have a multi-cylindrical structure with a high thermal resistance so as to minimize the intrusion of heat (release of cold and hot water). This is because, in the structure of the cryostat of the superconducting device described above, most of the heat that enters the helium container 2 comes through the path of the heat insulating supports 3a and 3b, and it is necessary to increase the thermal resistance of the heat insulating supports as much as possible. As mentioned above, the number of pieces used is a problem in relation to the support strength as well as the power. Based on this, the structure of the heat insulating support is as shown in Figure 4. Since the heat insulating support is made up of multiple cylinders and heat is transmitted as shown by the arrow, the length l of the cylinder of the heat insulating material is It is effective to make it as long and thin as possible.

Therefore, in order to support the cylinder in the horizontal direction, the smaller the amount of heat penetration, the smaller the rigidity of the support. The load capacity of the multi-cylindrical heat insulating support in the direction A in FIG. 4 is determined by the bending stress value of the cylinder, and the rigidity is determined by the deflection of the cylinder. On the other hand, the load resistance against the load in the B direction is determined by the compressive stress applied to the cross-sectional area of the cylinder or the adhesive force between the cylinders,
Rigidity is determined by length l and cross-sectional area. Comparing the load capacity and rigidity in both directions A and B,
There is no difference in load capacity, but the rigidity is overwhelmingly greater when the load direction is B. However, with a support having low rigidity, there is a concern that the helium container 2 will be shaken up and down significantly due to load fluctuations during transportation, and parts around the helium container 2 will be damaged, causing the superpower coil 9 to be affected greatly. Therefore, it is necessary to make the rigidity commensurate with the magnitude of the load. B direction (longitudinal direction)
As long as it can withstand a load, it has high rigidity, so the load will hardly shift. Therefore, since the load applied to the supports 3a and 3b during transportation is considered to be approximately 3:1.5 times the static load in the vertical and horizontal directions, multiple cylindrical heat-insulating supports 3a and 3b are arranged in plural numbers.
An economical portable heat insulating support can be provided by arranging the mounting directions of the parts 3b at a vertical:horizontal ratio of 2:1 as shown in FIG. Furthermore, as shown in Fig. 5, the compressive stress generated in each cylinder in the loading direction B is
It is inversely proportional to each cross-sectional area. That is, if the thicknesses of the cylinders 3-1 to 3-4 are constant, the cylinder with the smallest diameter is the largest. Therefore, by changing the thickness in inverse proportion to the diameter of each cylinder, a heat insulating support with a small amount of heat penetration can be obtained.

[Effects of the Invention] As described above, according to the present invention, a superconducting device that is transported while being cooled has sufficient mechanical support strength against vibrations and shocks associated with transportation,
Moreover, it is possible to provide a superconducting device having a support structure that can suppress heat intrusion as much as possible.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention in FIG. 3.
2 is a partially cutaway perspective view showing the entire superconducting device of the present invention, FIG. 3 is a longitudinal sectional view, FIG. 4 is a longitudinal sectional view showing the structure of the heat insulating support, and FIG. 5 is its - FIG. 1... Nitrogen container, 2... Helium container, 3...
Multiple cylindrical heat insulating support, 3-1 to 3-4...Cylinder 1
~4, 3a... Horizontal heat insulating support, 3b... Vertical heat insulating support, 4... Nitrogen container side mounting seat, 5...
Helium container side mounting seat, 6...Insulation support shaft, 7
...Insulated vacuum container, 8...Liquid helium, 9...
superconducting coil.

Claims (1)

[Scope of Claims] 1. A cylindrical coolant container is connected to the cylindrical heat insulating true container at its axial center in a cylindrical heat insulating vacuum container placed with its axial direction horizontal, and the cylindrical cooling A helium container storing a superconducting coil and liquid helium is supported and fixed on the inner peripheral side of the coolant container via arm-shaped mounting seats and heat insulating supports extending from both axial ends of the coolant container. A superconducting device, characterized in that the support points of the helium container by the heat insulating support are provided at a ratio of 1 in the vertical direction and 2 at symmetrical positions in the horizontal direction when viewed in a radial cross section of the helium container. 2. In the device according to claim 1,
A superconducting device characterized in that the heat insulating support has a multi-cylindrical structure, and the thickness of each heat insulating cylinder is varied so that the cross section of each heat insulating cylinder is approximately equal.