JPH0359433A - Sealing confirming method for pressure-reduced, sealed container - Google Patents

Abstract

PURPOSE:To enable sealing confirmation in a simple process by deairing and sealing the container, and then admitting gas for detection to the container and detecting its leak. CONSTITUTION:The container 10 is united by welding the peripheral edge parts of the container 11 which contains a body 13 to be processed and a lid 12 and a capsule 14 wherein the gas 15 for detection is charged and a height adjusting jig 16 are inserted into an exhaust pipe 121. Then the air in the container 10 is sucked through a connecting pipe 18 and the exhaust pipe 121 is clamped by a crashing jig 22 as shown in a figure (d) to cut off the flow passage of the air, sealing the container 10 hermetically. Then, the capsule insertion part is crashed by the jig 22 as shown in a figure (e) to admit gas 15 to the container 10, the exhaust pipe 121 is cut by a cutting jig 24 as shown in a figure (f), and the cut end part is welded as shown in a figure (g). Then the container 10 is put in a vacuum chamber 23 as shown in a figure (h) and evacuated into a vacuum state by a vacuum pump 25. At this time, if the sealing of the container 10 is imcomplete, the gas 15 may leaks out of the container and a gas detector 26 detects whether or not there is the gas 15 to accurately decide whether or not the sealing is normal.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for guaranteeing and confirming the sealing of a vacuum-sealed container whose interior is sealed under a reduced pressure state, or in some cases a vacuum state. Mainly HIP (llot
15osLaL1e Press) It is applied to processing containers, radioactive substance storage containers, etc.

[Conventional technology]

In recent years, the HIP method has been introduced as a means of reducing the volume of waste. In this HIP method, after a special container is filled with waste, it is necessary to seal the container while maintaining a vacuum inside the container. Furthermore, storage containers for radioactive materials may also require similar degassing and sealing to prevent the radioactive materials from scattering outside the container. Conventionally, such degassing and sealing was accomplished by attaching an exhaust pipe to the lid of the container in advance, welding the lid to the container, sucking the air inside the container through the exhaust pipe, and then crushing the exhaust pipe. This method is commonly used.

By the way, in such a vacuum-sealed container, there is a risk of leakage occurring due to pinholes in welds, etc., so after sealing, it is necessary to confirm and prove whether or not the sealing is complete.

Figures 4 (a) to (d) are examples of such seal confirmation methods.
) are known.

First, as shown in FIG. 4A, a container 90 to be checked is placed in a vacuum chamber 91, and the vacuum pump 93 is operated to bring the inside of the vacuum chamber 91 into a vacuum state. Next, as shown in FIG. 9B, a detection gas such as helium or argon is introduced from the supply cylinder 94 into the vacuum chamber 91 at a predetermined pressure and left for a certain period of time. At this time,
If the container 90 is incompletely sealed, the detection gas will enter the container 90.

Then, after exhausting the detection gas in the vacuum chamber 91 to the outside through the exhaust valve 95 (FIG. (c)),
Transferring the container 90 into another vacuum chamber 91',
Make the vacuum state again using the vacuum pump 93' ((d) in the same figure)
. At this time, if the container 90 is incompletely sealed,
Since the detection gas that has entered the container 90 should leak from the container 90, by checking the presence or absence of the detection gas with the gas detector 96, it is possible to determine whether the seal is successful or not.

In addition, as another seal confirmation method, a hole is provided in the lid of the container that communicates only with the inside of the container, and a detection gas is sealed in a capsule made of a material with a relatively low melting point (approximately 96°C). The lid and the container are welded and sealed with the MH installed in the hole in the lid, and then the MH mounting part of the capsule is locally heated to melt the capsule and introduce the detection gas into the container. Coguelsslon o (' tbe Eur
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According to this method, the container into which the detection gas has been introduced is directly transferred to the fourth container.
By carrying the sample into the vacuum chamber 91' shown in FIG. 9(d), sealing can be confirmed by checking the presence or absence of the detection gas.

[Problem to be solved by the invention]

In addition to the degassing and sealing process, the method shown in FIGS. 4(a) to 4(d) includes a degassing process in the vacuum chamber 91, a detection gas supply/exhaust process, and a detection gas detection process. This method has the disadvantage of requiring a large number of steps.

On the other hand, in the method of introducing detection gas into the container by melting the capsule, the welding of the lid and container body and the melting of the capsule must be performed in separate processes. It has the disadvantage of requiring a relatively long time. Furthermore, this method is for checking the sealing of a container that does not require internal pressure (deaeration), and it is difficult to apply it directly to containers that require deaeration.

In view of these circumstances, an object of the present invention is to provide a method that can reliably confirm the sealing of a vacuum-sealed container through simple steps.

[Means to solve the problem]

The present invention provides a reduced-pressure sealed container having an exhaust pipe that communicates the inside and outside with the steps of inserting a capsule filled with a detection gas one by one into the exhaust pipe and sucking the air inside the container from the exhaust pipe. The capsule is destroyed by crushing the part of the exhaust pipe outside the part where the capsule was inserted to seal the inside of the container, and then crushing the part of the exhaust pipe into which the capsule was inserted. The detection gas inside is introduced into the container, and then the container is placed in a testing chamber, and the presence or absence of the detection gas leaking from inside the container is detected (Claim 1).

The present invention also provides a method for sucking air inside the container from the exhaust pipe,
While maintaining a reduced pressure state, a sealing member having a capsule filled with a detection gas in its lower end is press-fitted into the exhaust pipe, thereby sealing the inside of the container, and contracting the lower end of the sealing member by the press-fitting. By this, the capsule is destroyed and the detection gas inside is introduced into the container,
Next, this container is placed in a testing chamber, and the presence or absence of a detection gas leaking from inside the container is detected (claim 2).

The present invention also provides a method for sucking air inside the container from the exhaust pipe,
While maintaining a reduced pressure state, insert a capsule filled with a detection gas into the exhaust pipe, then insert a sealing member to seal the inside of the container, and press the capsule with the lower end of this sealing member. The capsule is destroyed and the detection gas inside is introduced into the container, and then this container is placed in a testing chamber to detect the presence or absence of the detection gas leaking from inside the container (Claim 3). [Function] First, according to the method according to claim 1, after inserting the capsule into the exhaust pipe and deaerating the container, the container is crushed by crushing the part outside the insertion point of the capsule in the exhaust pipe. The container is sealed, and the detection gas is introduced into the container by crushing the insertion point of the capsule. Therefore, by detecting the leakage of the detection gas from this container,
You can check the seal.

Further, according to the method of claim 2, by inserting the capsule and the sealing member integrally into the exhaust pipe of the container after degassing, the interior of the container is sealed with the sealing member, and the lower end of the sealing member is sealed. When the capsule is destroyed by the contraction of the part, the detection gas inside is introduced into the container.

Further, according to the method according to claim 3, by first inserting the capsule into the exhaust pipe of the container after degassing, and then inserting the sealing member, the inside of the container is sealed with this sealing member, and the inside of the container is sealed. The capsule is destroyed by being pressed by the member, and the detection gas inside is introduced into the container.

〔Example〕

A first embodiment of the present invention will be described based on FIGS. 1(a) to 1(f).

The HIP processing container 10 shown in FIG.
2 is provided with an exhaust pipe 121 that communicates the space above and below. In such a container 10, the container body 11
After storing the required workpiece 13 inside, insert the lid 1 over it.
2, and the peripheral edges of the lid 12 and the container body 11 are joined by welding as shown in FIG. 1(b) to integrate the entire container 10.

Next, as shown in FIG. 2(b), the exhaust pipe 121
Insert the height adjustment jig 16 and capsule 14 into the container. The height adjustment jig 16 is formed into a cylindrical shape that opens upward and downward, and allows air to pass through it. The capsule 14 is made of a material that is relatively easy to crush, such as aluminum, quartz, or glass, and a detection gas 15 such as helium or argon is sealed therein.

In this state, as shown in FIG. 1(c), the exhaust pipe 1
A connecting pipe 18 is connected to the upper end of the container 21, and a vacuum pump 20 is used to pump the container 1 through the connecting pipe 18 and exhaust pipe 121
The air inside the container is sucked out, thereby creating a vacuum inside the container.

While maintaining this reduced pressure state, a portion of the exhaust pipe 121 outside (in the figure, above) the portion into which the capsule 14 is inserted is clamped with a crushing jig 22 as shown in FIG. 1(d). This blocks the air flow path, and the container 1
0 is in a sealed state. Then, by pinching the portion into which the capsule 14 is inserted with the crushing jig 22 as shown in FIG. Detection gas 15
is introduced into the container 10 through the height adjustment jig 16. Further, the exhaust pipe 121 is cut using the cutting jig 24 shown in FIG. 12(f), and the cut end portion is welded as shown in FIG. 12(g).

This container 10 is placed in a vacuum chamber (examination chamber) 23 as shown in FIG. At this time, if the sealing of the container 10 is incomplete, the detection gas 15 introduced therein should leak to the outside of the container 10.
By detecting the presence or absence of 5 with the gas detector 26, it is possible to accurately determine whether or not the container 10 is sealed.

As described above, in this method, the capsule 14 can be destroyed by the same operation as the sealing operation of the container 10, that is, the operation of crushing the exhaust pipe 121, and the detection gas 15 inside can be introduced. It is easy and accurate to detect the leakage of the detection gas 15 from the container 1.
You can see the seal of 0.

Next, a second embodiment will be described based on FIGS. 2(a) to 2(c).

Here, the work up to welding the M12 to the container body 11 is the same as in the first embodiment, but the interior of the container 10 is kept in a vacuum state by placing it in a vacuum chamber (not shown). In this state, in the exhaust pipe 121 of the container 10,
A sealing member 27 as shown in FIG. 2(b) and a capsule 14 filled with the detection gas 15 are inserted together. The seal member 27 has a split groove 271 at its lower end.
When the upper end of the capsule 14 is press-fitted into the split groove 271, the lower end of the seal member 27 is expanded in diameter.

By press-fitting the sealing member 27 as it is into the exhaust pipe 121, the inside of the container 10 is sealed with this sealing member 27, and the lower end of the sealing member 27 is pushed against the inner wall of the exhaust pipe 121 and contracted. As a result, the capsule 14 that had been press-fitted into the sealing member 27 is pressed from the outside and destroyed, and the detection gas 15 that was sealed therein is released.
is introduced into the container 10 as shown in FIG. 2(b). After that, as shown in FIG.
7 to the exhaust pipe 121 by welding, and the entire container is connected to the first
The seal can be confirmed by placing it in the vacuum chamber 23 shown in Figure (h) and performing the same operations as in the previous embodiment.

Next, a third embodiment will be described based on FIGS. 3(a) and 3(b).

In the method shown here, after inserting the height adjustment jig 16 and the capsule 14 into the exhaust pipe 121 in the same way as in the first embodiment, the lower end is shaped like a pointed tip as shown in FIG. 3(a). The sealing member 28 is press-fitted, and this sealing member 28 seals the container 1.
0 is sealed, the lower end is pressed against the capsule 14 to destroy the capsule 14, and the detection gas 15 inside is introduced into the container 310 (FIG. 3(b)).
) Also in this method, the container 10 is sealed by the sealing member 28.
After the container 10 is sealed, the sealing can be confirmed by carrying the container 10 into the vacuum chamber 23 shown in FIG. 1(h).

Note that the present invention is not limited to such embodiments, and may take the following embodiments as examples.

(1) In the present invention, regardless of the specific material or structure of the capsule, for example, a detection gas such as argon is trapped in the molecular-sized pores of the zeolite material, and this zeolite powder or the same zeolite is sealed in the capsule. In the present invention, "
It can be used as a capsule. in this case,
By applying a strong force to the zeolite using the crushing jig 22 or the like, a portion of the detection gas is released from the zeolite.

(2) In the present invention, the type of gas for detection does not matter.

However, by using an inert gas such as argon or helium, it is possible to reliably prevent the detection gas from affecting the object to be processed.

(3) In the present invention, the shape of the container is not particularly limited, and the shape of the exhaust pipe may be appropriately set as necessary.

(4) The present invention is not limited to containers whose insides are kept in a completely vacuum state, such as containers for HIP processing, but also containers whose interiors are simply sealed under reduced pressure, such as storage containers for release-resistant substances. It can also be applied to

〔Effect of the invention〕

As described above, the present invention destroys the capsule filled with the detection gas and introduces the gas into the container with approximately the same action as the container sealing action, so that pressure fluctuations are not repeated many times. The present invention has the effect that sealing can be easily and reliably confirmed by simply detecting the presence or absence of leakage of the detection gas without performing special operations such as heating the container.

[Brief explanation of drawings]

Figure 1 (a) (b) (c) (d) (e) (f
)(g)(h) are process diagrams showing the first embodiment of the present invention, FIGS. 2(a), (b), and (c) are process diagrams showing the second embodiment of the present invention, and FIG. )(b) is a process diagram showing a third embodiment of the present invention, and FIGS. 4(a), (b), (c), and (d) are process diagrams showing a conventional seal confirmation method for a volume-reducing sealed container. 10... Container, 11... Container body, 12... Lid,
1391. Processing object, 14... Capsule, 15...
Detection gas, 22... Crushing jig, 23... Vacuum chamber (inspection room), 25... Gas detector, 27.28.
...Seal member.

Claims (1)

[Scope of Claims] 1. In a vacuum sealed container having an exhaust pipe that communicates between the inside and the outside, the work includes inserting a capsule filled with a detection gas into the exhaust pipe, and sucking air inside the container from the exhaust pipe. The capsule is destroyed by crushing the part of the exhaust pipe outside the part where the capsule is inserted to seal the inside of the container, and then crushing the part of the exhaust pipe into which the capsule is inserted. A method for checking the sealing of a vacuum-sealed container, characterized in that the detection gas inside the container is introduced into the container, and then the container is placed in an inspection chamber, and the presence or absence of the detection gas leaking from inside the container is detected. 2. In a vacuum sealed container having an exhaust pipe that communicates the inside and outside, a sealing member that sucks the air inside the container through the exhaust pipe and press-fits a capsule filled with a detection gas into the lower end while maintaining the vacuum state. is press-fitted into the exhaust pipe, thereby sealing the inside of the container, and by contracting the lower end of the sealing member by the press-fitting, the capsule is destroyed and the detection gas inside is introduced into the container. A method for checking the sealing of a vacuum-sealed container, characterized by placing the container into an inspection chamber and detecting the presence or absence of a detection gas leaking from inside the container. 3. In a vacuum-sealed container having an exhaust pipe communicating between the inside and outside, suck the air inside the container through the exhaust pipe, and while maintaining the vacuum state, insert a capsule filled with a detection gas into the exhaust pipe, Next, the inside of the container is sealed by inserting a sealing member, and the capsule is destroyed by pressing the capsule with the lower end of this sealing member, and the detection gas inside is introduced into the container, and then this container is inspected. A method for checking the sealing of a vacuum-sealed container, characterized by detecting the presence or absence of a detection gas leaking from inside the container by placing the container indoors.