JPS5844234B2 - Support structure of vacuum vessel for plasma generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a support structure for a vacuum vessel used in a plasma generator.

A vacuum container used in a plasma generator has the function of maintaining an ultra-high vacuum inside and forming plasma, but there are various restrictions regarding the support structure of the container.

In other words, since toroidal coils and poloidal coils are installed around the vacuum vessel, there are restrictions on the placement of the support structure, and the support structure tends to be redundant due to the structure between the support part of the vacuum vessel and the external frame. Yes, electromagnetic force,
It is not easy to maintain sufficient rigidity against loads such as own weight or earthquakes.

Further, since it is necessary to install a large number of measurement ports and through holes around the body of the vacuum vessel, the arrangement of the support structure is further restricted.

In addition to the above-mentioned conditions regarding arrangement and strength, there are also requirements to improve the accuracy of the center of the container when forming plasma,
It is necessary to take measures in the design of support structures to deal with the effects of thermal expansion displacement.

A conventional support structure for a vacuum container has a structure in which support legs are provided at the bottom of the vacuum container and the support legs are connected to a pedestal or the like.

However, in such a support structure, since the center of gravity of the vacuum vessel is located at the center of the vacuum vessel, a so-called "top-heavy" support design is required for earthquake resistance, and it is therefore difficult to obtain a structure with sufficient horizontal rigidity. Therefore, it was necessary to install it in a limited space.

In addition, since the starting point of thermal expansion is at the lower end of the vacuum container, the thermal displacement of the vacuum container, which is normally heated to about 200'C to 3500C, becomes considerably large at the upper end, causing the coil and other lead wires and piping Countermeasures were needed to absorb relative displacements such as

Furthermore, since toroidal coils are installed around the torus-shaped vacuum vessel, the gaps between the coils are in close contact at the center of the vacuum vessel, and are maximum at the outer periphery.

Therefore, the support structure installed at the bottom of the vacuum vessel must be located in a gap away from the part where the coil is in close contact, and there are severe restrictions on the placement of the support structure. Satisfying the rigidity of the support legs of the support structure below, installing lead wires, various measurements, etc.
It was quite difficult to take measures regarding maintenance.

This invention has sufficient strength to maintain the accuracy of the vacuum container essential for plasma formation, and can maintain the symmetry of the vacuum container even against thermal expansion displacement of the vacuum container.
Another object of the present invention is to provide a support structure for a vacuum vessel for a plasma generator that has advantages in terms of arrangement regarding disassembly, assembly, and maintenance.

Hereinafter, details of the present invention will be explained based on drawings showing one embodiment.

As shown in FIGS. 1 and 2, the vacuum container 2 is an annular body having a substantially semicircular cross section, and each divided section 4, 6, and 8
are connected via bellows 10.

A toroidal coil 12 and a poloidal coil 14 are installed on the outer periphery of the vacuum vessel 2, and a vacuum vessel internal coil 16, a liner 18, etc. are located inside the vacuum vessel 2, and plasma is formed inside the vacuum vessel 2 by these components. It also functions to limit the size of the plasma and maintain stability.

The toroidal coil 12 is supported by a support 20, and since a strong electromagnetic force acts on the toroidal coil 12, the support 20 has sufficient support rigidity.

The vacuum vessel is supported by a support structure 22.

As shown in FIG. 2, the support structure 22 includes the toroidal coil 1
It is located at the center of the outer periphery of 2, that is, near the location where the gap between adjacent toroidal coils 12 is maximum, and is attached to the support body 20.

In particular, as shown in detail in FIGS. 3A and 3B, the support structure 2
2 supports from below a port 24 installed on the wall of the vacuum container 2 and used for purposes such as measurement, and therefore supports the vacuum container 2 via the port 24.

Support structure 22 consists of lugs 26, brackets 28, shoe plates 30, and support bases 32.

The lug 26 is fixed to the lower part of the port 24 and is slidably received in a groove of a bracket 28.

The groove of the bracket 28 is formed in the same direction as the axis of the port 24, so that the lug 26 is slidable only in the direction of the groove of the bracket 28.

Brackets 28 and lugs 26 are used to facilitate this sliding movement.
A shoe plate 30 is disposed on the sliding portion of the shoe.

The bracket 128 is fixed to the support stand 32, and the support stand 3
2 is fixed to a support body 22.

The supporting structure of the vacuum vessel for a plasma generator configured in this way supports the vacuum vessel at the port, and therefore supports the vacuum vessel approximately at its center of gravity. It has a more rigid structure than a support, and is stable against the effects of instantaneous and strong electromagnetic force and earthquake loads. Therefore, it is easy to maintain the accuracy of the vacuum vessel, which is essential for plasma formation. can do.

In addition, a vacuum container is subject to thermal expansion displacement due to heating, but in the support structure according to the present invention, the support structure according to the present invention allows for free movement in the radial direction using a radial axis, while vertical displacement is supported at the vertical center position of the vacuum container. , the expansion of the vacuum container is free.

Therefore, the symmetry of the vacuum container can be maintained even against thermal expansion displacement, and reliability in plasma formation is improved.

Furthermore, since the support structure of the present invention is installed at the part where the gap between adjacent toroidal coils is maximum, there are no particular restrictions on the placement of the support structure, and it is also possible to perform measurements using vacuum vessel ports. It does not interfere with the purpose.

Furthermore, it is easier to disassemble, assemble, and maintain than the conventional vacuum container support structure from the bottom.

Moreover, with the conventional structure of supporting the vacuum container from the bottom,
The support structure was installed in a part where the gap between the toroidal coils was small, and therefore the structure was dense, making it difficult to fuse heat, various measurements, or take out the lead wires of the coils, etc. According to the invention, such drawbacks are also improved.

Further, by using the reinforcing member 34, the port 24 can be reinforced.

As is clear from the above description, according to the present invention, the vacuum container has sufficient strength to maintain the accuracy of the vacuum container, which is essential for plasma formation, and the symmetry of the vacuum container is maintained even with respect to thermal expansion displacement of the vacuum container. In addition, it is possible to obtain a support structure for a vacuum vessel for a plasma generator, which has advantages in terms of arrangement with respect to disassembly, assembly, and maintenance.

[Brief explanation of the drawing]

FIG. 1 is an elevational view showing an example in which a support structure according to an embodiment of the present invention is installed in a vacuum vessel of a plasma generator having a valve-type toroidal cross section, and FIG. 2 is a vacuum vessel shown in FIG. 1. FIG. 3A is an enlarged front view of the support structure shown in FIG. 1, and FIG. 3B is a side view of the support structure shown in FIG. 3A. 2... Vacuum container, 12... Toroidal coil, 20... Support body, 22... Support structure, 24... Hoard, 26 ......Lug, 28...Bracket, 30...Shoe plate, 32...Support stand.

Claims (1)

[Claims] 1. A lug is fixed to the lower side of the port that is formed to protrude outward from the surface of the vacuum container for the plasma generator, and a shoe provided between the lug and the bracket is fixed to the support stand at the fixed position. A support structure for a vacuum vessel for a plasma generator, characterized in that the support structure is configured to slidably receive the lug via a plate.