JPS6332177A - Vacuum exhaust device - Google Patents

Abstract

PURPOSE:To facilitate the introduction of a dry gas by introducing said dry gas from a branch pipe provided in between a high vacuum valve and a low vacuum pump in a rough introducing system, and providing a valve having a defined conductance in between said branch pipe and said low vacuum pump. CONSTITUTION:A vacuum container 8 is pipingly connected to a low vacuum pump 10 via a high vacuum valve 3 forming a rough introducing system, and a valve 5 having a defined conductance is provided midway in the piping between a branch pipe provided in between the high vacuum valve 3 and the low vacuum pump 10, and the low vacuum pump 10. When the vacuum container 8 is opened to the air, a dry gas in a gas cylinder 7 is introduced into the vacuum container 8 via the valve 3. Thereby, a dry gas introducing operation can be easily carried out.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a vacuum evacuation device, and particularly to a vacuum evacuation device having a structure suitable for easily introducing dry gas for opening to the atmosphere into a vacuum container. .

[Conventional technology]

The general configuration of a conventional vacuum evacuation device is shown in FIG. A low vacuum pump (rotary pump, etc.) 10, which is used as an auxiliary pump or a rough pump for the high vacuum pump 9, is connected via a low vacuum valve 2 to the anti-vacuum vessel side of the high vacuum pump 9. The vacuum evacuation system has a main evacuation system, and a low vacuum pump 10 is piping connected to the vacuum container 8 via a high vacuum valve 3 to form a rough evacuation system.

In this case, generally, to open the vacuum container 8 to the atmosphere, air from the atmosphere is introduced into the vacuum container 8.

Moisture in the air is adsorbed on the inner wall of the vacuum container 8.

If you want to evacuate to high vacuum again in this state.

It is necessary to perform baking for a long time, which results in a lot of wasted time. Therefore, a drying gas such as nitrogen gas is usually introduced. Therefore, the vacuum container 8 is usually provided with a port for introducing dry gas.

In Figure 2, high vacuum valve 4. Dry gas can be introduced into the vacuum container 8 from the gas cylinder 7 via the pressure reducing valve 6, but at this time, in order to shorten the time required for opening to the atmosphere, a low vacuum is introduced as shown in FIG. The low vacuum pump 12 is operated while the pump 10 is in operation, and the low vacuum pump 10 is stopped after the pressure at part 0 in FIG. 2 becomes sufficiently low. In addition, since the degree of vacuum reached by the vacuum vessels 8 and 0 is different, pumps having pumping speeds corresponding to the degrees of vacuum are required. Therefore, a 10°12 low vacuum pump was installed in each of the vacuum exhaust system and gas introduction system6.
When introducing gas, the low vacuum pump 12 first exhausts the air accumulated in the 0 part piping while the low vacuum pump 10 is in operation, and then stops the low vacuum pump 1o and closes the valve 5.
' is closed, the pressure reducing valve 6 is set to a predetermined value, the high vacuum valve 4 is opened, and the dry gas in the gas cylinder 7 is introduced into the vacuum container 8 without being mixed with air.

Incidentally, as a similar device, there is a vacuum evacuation device CAT, No. F725-1010 manufactured by Tai-A Vacuum Giken Co., Ltd.

[Problem that the invention seeks to solve]

The conventional method described above has the following problems.

(1) If the gas cylinder 7 is used in applications where it is frequently exposed to the atmosphere, the gas cylinder 7 will have to be replaced frequently, and it will be necessary to evacuate the section ω in Figure 2 each time. You need to drive every time.

(2) Installation space for the low vacuum pump 12 is required,
Compact design is not possible.

(3) Since there is a dry gas introduction port, the number of flange joints and welded parts increases in the vacuum container 8, and the reliability of making the vacuum container 8 a high vacuum is lacking.

The purpose of the present invention is to facilitate the drying gas introduction operation, to make the vacuum pump for exhausting the drying gas introduction piping common to the low-vacuum pump used in the vacuum evacuation system, and to reduce the number of negative ports in the vacuum container. The object of the present invention is to provide a vacuum evacuation device that can improve reliability.

[Means for solving problems]

The above purpose is to provide a branch pipe that branches from between the high vacuum valve and the low vacuum valve of the roughing system, which are pipe-connected from the vacuum container to the low vacuum pump via the high vacuum valve, and to connect this branch pipe to the low vacuum pump. This is achieved by introducing a dry gas for opening the container to the atmosphere, and further by connecting a valve having a predetermined conductance between the branch pipe and the low vacuum pump.

[Effect]

The exhaust work of the dry gas grave piping can be performed only by opening and closing a specially provided valve during vacuum exhaust operation, and
Since the exhaust pump for the dry gas inlet piping is shared with the low vacuum pump for the vacuum exhaust system, the installation space can be reduced and the system can be made more compact. Furthermore, there is no need to attach the dry gas introduction port to the vacuum container, reducing the possibility of leakage and improving reliability.

〔Example〕

The present invention will be explained in detail below using the embodiment shown in FIG.

FIG. 1 is a configuration diagram showing an embodiment of the vacuum evacuation device of the present invention. In Fig. 1, 8 is a vacuum container, and this vacuum container 8 and a high vacuum pump (turbo molecular pump, cryopump, diffusion pump, etc.) 9 that evacuates to high vacuum.
A low vacuum pump (
A rotary pump, etc.) 10 is connected to the anti-vacuum container side of the high vacuum pump 9 via a low vacuum valve 2 to form a main exhaust system, and a low vacuum pump is connected from the vacuum container 8 to the high vacuum valve 3 via piping. 10 to form a roughing system, the high vacuum valve 3 of the roughing system and the low vacuum pump 10
A branch pipe is provided that branches from between the pipes, and a pressure reducing valve 6 is installed in this pipe.
A gas cylinder 7 is connected thereto, and a valve 5 having a constant conductance is provided in the middle of the piping between the branch section and the low vacuum pump 10.

The procedure for evacuating the vacuum volume ry8 of the vacuum evacuation apparatus configured according to the embodiment of the present invention described above will now be described.

(a) First, operate the low vacuum pump 1o, and open the valve 5°3.
is open and other valves are closed.

(b) When the degree of vacuum in the vacuum container 8 decreases (depending on the type of pump used, 1) If it is a normal rotary pump, 1
~Q, about ITorr), close valves 3 and 5, and close valve 2
Let's open.

(c) Operate the high vacuum pump 9 and open the valve 1 when steady operation is reached.

The above is the procedure for evacuation, but when the inside of the vacuum container 8 is to be opened to the atmosphere, (d) the valve 5 is opened following the above evacuation procedure.

(E) When the degree of vacuum has decreased to a certain degree (about several Torr) at 0 in FIG. 1, valve 1 is closed, high vacuum pump 9 is stopped, and valve 2 is closed.

(f) Close the valve 5 and stop the low vacuum pump 10.

(g) Set the pressure reducing valve 6 to a predetermined value, open the valve 3, and introduce the dry gas in the gas cylinder 7 into the vacuum container 8.

The problem with this work when venting to the atmosphere is that in order to shorten the time required for venting to the atmosphere, the low vacuum pump 10 evacuates the exhaust section and zero section of the high vacuum pump 9 in parallel, so the pumping speeds of each becomes 1/2 (assuming the pipe diameter and length are the same), causing a pressure increase in the exhaust part of the high vacuum pump 9,
As a result, the degree of vacuum in the vacuum container 8 may be deteriorated. Therefore, in order to increase the pumping speed of the pumping section of the high vacuum pump 9, the valve 5 is made to have a certain certain conductance to reduce the influence on the vacuum vessel 8. Therefore, the pumping speed of the 0th part decreases by that amount, but since the volume of the 0th part is small, there is no particular effect.

This makes it possible to exhaust the inside of the 0-part pipe and introduce dry gas into the vacuum container 8.

〔Effect of the invention〕

As explained above, according to the present invention, the exhaust work of the dry gas inlet piping can be easily performed by simply opening and closing the valve using the low vacuum pump of the vacuum exhaust system, and the number of vacuum pumps can be reduced. , the installation space can be reduced, the vacuum evacuation equipment including the gas inlet for venting to the atmosphere can be made more compact, and there is no need to attach the drying gas inlet port to the vacuum container, reducing the possibility of leaks. This has the effect of improving reliability.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing an embodiment of the vacuum evacuation device of the present invention, Fig. 2 is a configuration diagram of a conventional vacuum evacuation device, and Fig. 3 shows the low vacuum pump operation timing of the vacuum evacuation device according to the conventional technology. It is a diagram. 1.3...High vacuum valve, 2...Low vacuum valve, 5
...Valve, 6...Reducing valve, 7...Gas cylinder,
8...Vacuum container, 9...High vacuum pump, 1o...
low vacuum pump.

Claims (1)

[Claims] 1. A main exhaust system in which a high vacuum valve, a high vacuum pump, a low vacuum valve, and a low vacuum pump are connected in series to a vacuum container that maintains a vacuum inside, and a high vacuum valve separately provided from the vacuum container. In a vacuum evacuation apparatus comprising a roughing system connected to the low vacuum pump by piping, a branch pipe is provided that branches from between the high vacuum valve of the roughing system and the low vacuum pump, and the 1. A vacuum evacuation device, characterized in that it is configured to introduce dry gas for opening the vacuum container to the atmosphere, and further configured to connect a valve having a predetermined conductance between the branch pipe and the low vacuum pump.