JPS62180168A - Sealing mechanism for vacuum vessel - Google Patents

Abstract

PURPOSE:To improve sealing quality for a vacuum vessel by providing double gaskets to be arranged at both internal and external sides on the joint surfaces of connection flanges, and forming an intermediate gas chamber sealed with the same kind of gases as those in the vacuum vessel between both of said gaskets. CONSTITUTION:At the joint surfaces of connection flanges 21a and 22a for vacuum vessel, there are double gaskets 31 and 32 provided for arrangement on both internal and external sides. And an intermediate gas chamber 33 sealed with the same kind of gases as those in said vessel is formed between both gaskets 31 and 32. Consequently, as the gaskets 31 and 32 are double-structured, a leak amount is reduced and outside air is thinned through the mixing thereof with gases in the intermediate chamber 33, even if there is an ingress of outside air due to a leak, thereby keeping the inside of the vacuum vessel almost free from an ingress of outside air.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sealing mechanism for a vacuum vessel, which is applied to a vacuum vessel such as a vacuum vessel for plasma confinement of a nuclear fusion device.

[Conventional technology]

FIG. 3 is a perspective view showing an example of a vacuum vessel for plasma confinement of a nuclear fusion device. As shown in FIG. 3, this type of vacuum vessel 10 is generally divided into a plurality of, for example, three, vacuum vessel constituent members 11. 12.13
are formed by airtightly joining them at the joining flange portions 14 and 15. Therefore, for joining 7
The vacuum sealing mechanism in the flange 14.15 is necessarily a core plate. Further, a vacuum sealing mechanism is also required for the flange portion 17 for attaching the port 16 to the vacuum container 10.

FIG. 4 is a sectional view showing an example of a conventional vacuum sealing mechanism of this type. In FIG. 4, 21a indicates one of the vacuum vessel constituent members, and 21b indicates a joining flange thereof. Further, 22a indicates the other vacuum container component;
b indicates the joining flange. 23 is a gasket interposed between both flanges, and 24 is a bolt for tightening. Thus, by tightening the bolt 24, a vacuum seal is created by the gasket 1-23.

FIG. 5 is a sectional view showing another example of a conventional vacuum sealing mechanism of this type. The vacuum seal mechanism shown in FIG. 5 is a seal mechanism in which electrical insulation means is added to the vacuum seal mechanism shown in FIG. 4. In Fig. 5, 23a and 23b are a pair of gaskets, 25 is an insulating plate interposed between both flanges, 26 is an insulating cylinder fitted with a bolt 24 for tightening, and 27 is an insulating washer. be. Thus, the insulating plate 25. Insulating cylinder 2'6. Insulation washer 27 ensures insulation between flanges 21b and 22b, and
Tightening is done by operating the bolt 24.
Vacuum sealing is performed using gaskets 23a and 23b.

[Problem that the invention seeks to solve]

With the configuration shown in FIG. 4 or FIG. 5, it is possible to vacuum-seal with high reliability between the gasket 23 and the seven langes 21t) and 22b or between the gaskets 23a and 23b and the insulating plate 25. It's not always easy. Especially the flange 21b.

When the size of 22b is increased or when an insulating member is interposed as shown in FIG. 5, it is inevitable that some leakage will occur during manufacturing, assembly, and operation. However, in a nuclear fusion device, even a small amount of air entering the vacuum vessel due to a leak causes impurities to interfere with the plasma, resulting in a large adverse effect. Therefore, it is necessary to reliably prevent this.

Therefore, the present invention has developed a vacuum container seal IFN@ which can prevent impurities from entering the vacuum container even if the sealing function of the gasket is insufficient, and which does not pose a risk of impairing the function of the vacuum container. The purpose is to provide.

[Means for solving problems]

In order to solve the above-mentioned problems and achieve the object, the present invention takes the following measures. That is, in a vacuum container sealing mechanism that airtightly seals the joining surfaces of each joining flange of a pair of vacuum container constituent members to be joined, (1) the inner part and the outer part between the joining surfaces of each joining flange; Provide double gaskets in both parts. (2) An intermediate gas chamber is provided in the middle of this double gasket, which is filled with the same type of gas as the gas sealed in the vacuum container.

[Effect]

Since the gasket has a double structure, the amount of leakage itself is suppressed to a very small amount, and even if outside air enters due to a leak, the outside air will be diluted by the gas in the intermediate gas chamber, so it will not leak into the vacuum container. The main component of the invading gas is almost the same as the gas sealed in the vacuum container.

〔Example〕

FIG. 1 is a diagram showing a first embodiment of the present invention.

Note that the same parts as in FIG. 4 are given the same reference numerals and detailed explanations will be omitted. As shown in the first factor, each joining flange 21
A first gasket 31 is provided at the inner portion between the joint surfaces of a and 22a, and a second gasket 3 is provided at the outer portion.
2 is provided, and the gasket has a double structure. In the middle of this double structure gasket 31 and 32,
An intermediate gas chamber 33 is provided. Inside the intermediate gas chamber 33, the same type of gas as the gas sealed in the vacuum container (
In the vacuum vessel of a nuclear fusion device, hydrogen (hydrogen, hydrogen isotopes such as deuterium, tritium, etc.) is sealed at a constant pressure. Note that the above pressure is set to be lower than atmospheric pressure. .

In this seal mechanism having the above configuration, the gasket 31.
Even if a leak occurs due to the insufficient sealing function of the vacuum chamber 32 and outside air tries to enter the vacuum chamber, the outside air is diluted by the gas inside the intermediate gas chamber 33, so the main component of the gas that enters the vacuum chamber is , the same type of gas as originally sealed in the vacuum container. Therefore, the adverse effects of impurities entering the vacuum container are significantly reduced. Also the first
．． The gasket has a double structure with the second gasket 31 and 32, and the pressure of the gas in the intermediate gas chamber 33 is set to be lower than atmospheric pressure; therefore, leakage into the vacuum container is prevented. is kept sufficiently small.

FIG. 2 is a sectional view showing a second embodiment of the present invention. This embodiment differs from the first embodiment in that the intermediate gas to 33
An inlet/exhaust pipe 34 is connected to the intermediate gas chamber 33 so that the gas in the intermediate gas chamber 33 can be constantly exhausted and injected.

In this embodiment configured as described above, in use, first, the atmosphere in the intermediate gas chamber 33 is forcibly replaced with the gas sealed in the vacuum container through the inlet/exhaust pipe 34, and then the air is exhausted through the inlet/exhaust pipe 34. At the same time, the same kind of gas is injected so that the interior of the intermediate gas chamber 33 is always filled with a predetermined gas at a constant pressure. Therefore, according to this embodiment,
Even if air enters from the outside due to a small leak in the second gasket 32, the amount of air remaining in the intermediate gas chamber 33 is maintained because the inside of the intermediate gas chamber 33 is always ventilated with the same type of gas. is relatively small. Therefore, the amount of atmospheric components that enter the vacuum container through the first gasket 31 is close to zero. Of course, other than the above, the same operation and effect as the first embodiment is achieved.

Note that the present invention is not limited to the above embodiments.

For example, in the above embodiment, the first. Second gas get 31.3
2 are each configured with a single gasket, but 1. Each of the second gaskets 31, 32 may be composed of a plurality of gaskets. Similarly, a plurality of intermediate gases W33 may be provided. Further, in the above embodiments, the present invention is applied to a flange portion without an insulating member, but it is of course applicable to a flange portion having an insulating member interposed therebetween. It goes without saying that various other modifications can be made without departing from the gist of the present invention.

〔Effect of the invention〕

According to the present invention, double gaskets are provided at the inner part and the outer part between the joining surfaces of each joining flange, and the gasket is placed between the double gaskets and is sealed inside the vacuum container. Since we have created an intermediate gas space that is filled with the same type of gas as the gas being used, the gasket has a double structure, so the amount of leakage itself is suppressed to a very small amount, and the intrusion of outside air due to leakage is also prevented. Even if there is, the outside air will be diluted by the gas in the intermediate gas gap, and the main component of the gas entering the vacuum container will be almost the same as the gas sealed inside the vacuum container. In this way, even if the sealing function of the gasket is insufficient, it is possible to prevent impurities from entering the vacuum container, and it is possible to provide a sealing mechanism for a vacuum container that is free from the risk of impairing the function of the vacuum container.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a first embodiment of the invention, and FIG. 2 is a sectional view showing a second embodiment of the invention. FIG. 3 is a perspective view showing an example of a vacuum container for a nuclear fusion device;
4 and 5 are cross-sectional views showing different examples of conventional vacuum seal mechanisms, respectively. DESCRIPTION OF SYMBOLS 10... Vacuum container, 11, 12.13... Vacuum container component, 14.15... Flange part, 16... Boat, 17... Flange part, 21a, 22a... Vacuum container Component members, 21b, 22b...flange, 23
゜23a, 23b... Gasket, 24... Tighten with bolt, 25... Insulating plate, 26... Insulating cylinder, 27...
...Insulating washer, 31...First gasket, 32
...Second gasket, 33...Intermediate gas chamber, 34
...Injection and exhaust pipes.

Claims (1)

[Claims] In a vacuum container sealing mechanism that airtightly seals the joining surfaces of each joining flange of a pair of vacuum container constituent members to be joined, an inner region and an outer region between the joining surfaces of each joining flange are provided. A double gasket is provided, and an intermediate gas chamber is provided between the double gaskets and is filled with the same type of gas as the gas sealed in the vacuum container. Vacuum seal mechanism for vacuum containers.