JP3275098B2 - Vacuum exhaust device and start-up method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for starting an evacuation apparatus, and more particularly to an apparatus for evacuation of a vacuum vessel requiring a high degree of vacuum, such as a space environment test apparatus, and an activation method thereof.

[0002]

2. Description of the Related Art As a vacuum exhaust device for evacuating a vacuum vessel to a high vacuum, a system shown in FIG. 3 is widely used. This vacuum pumping device is provided in the vacuum vessel 1.
A turbo-molecular pump 2 for evacuating the inside to a high vacuum and an oil rotary pump 3 for evacuating the vacuum vessel 1 to a pressure at which the turbo-molecular pump can be operated are provided in parallel. A valve 4 is provided, and an oil rotary pump 5 having a smaller capacity than the oil rotary pump 3 is provided on the outlet side of the turbo molecular pump 2. An exhaust valve 6 is provided on the inlet side of the oil rotary pump 3, and a system is provided between the outlet side of the turbo molecular pump 2 and the oil rotary pump 5 and between the exhaust valve 6 and the vacuum vessel 1. Atmospheric pressure return valves 7, 8 for returning to atmospheric pressure are provided.

[0003] The vacuum vessel 1 is provided with a vacuum gauge 9 for monitoring the degree of vacuum in the vessel 1.

In order to evacuate the vacuum vessel 1 from atmospheric pressure to high vacuum using the above-described vacuum exhaust device, first, the inlet valve 4 and the atmospheric pressure return valves 7 and 8 are closed, and the exhaust valve 6 is opened to rotate the oil. The operation of the pump 3 is started. Then, when the pressure inside the vacuum vessel 1 becomes the operable pressure of the turbo-molecular pump, usually about 0.1 Torr, the operation of the turbo-molecular pump 2 and the oil rotary pump 5 is started, and the inlet valve 4 is gradually opened and the exhaust is started. Valve 6
Close.

Thereafter, the vacuum vessel 1 is evacuated to a high vacuum by the operation of the turbo molecular pump 2, and the oil rotary pump 5 exhausts the outlet side of the turbo molecular pump 2.

When returning the pressure in the vacuum vessel 1 to the atmospheric pressure, the pumps are stopped and the atmospheric pressure return valves 7 and 8 are opened.

[0007]

In the vacuum evacuation apparatus having the above structure, when the apparatus is stopped in the middle of evacuation, conventionally, the inside of the vacuum vessel 1 and the evacuation system are returned to the atmospheric pressure, and the atmospheric pressure is reduced. Had been evacuated. The reason is that, when the exhaust valve 6 is opened when the inside of the vacuum vessel 1 is at a high vacuum exceeding the capacity of the oil rotary pump 3, the oil and oil vapor of the oil rotary pump 3 flow into the vacuum vessel 1 due to the differential pressure. If the inlet valve 4 is opened when the pressure inside the vacuum container 1 is equal to or higher than the operable pressure of the turbo-molecular pump, the turbo-molecular pump 2 during operation may be damaged. There are things.

That is, even if a control means for controlling each pump and valve is conventionally provided, the control operation is intended only for evacuation from the atmospheric pressure, and the control operation of the apparatus during the evacuation operation is performed. Startup and restart were not considered. Further, even if the operation is manually restarted, the valve must be opened and closed while checking the indicated value of the vacuum gauge 9 and the operation state of each pump. It was necessary to pay attention.

Further, the conventional apparatus has a large number of pumps and valves, and has only one vacuum gauge for the vacuum vessel. Therefore, it is impossible to incorporate a restarting step into the control apparatus as it is.

Therefore, the present invention simplifies the apparatus configuration and automatically controls each pump and valve in accordance with the pressure in the vacuum vessel so that the vacuum vessel can be started from the atmospheric pressure and maintained in a vacuum state. An object of the present invention is to provide an evacuation apparatus and a method for starting the evacuation apparatus, which can also be automatically restarted.

[0011]

In order to achieve the above-mentioned object, the present invention provides a vacuum pumping apparatus comprising: a turbo-molecular pump for evacuating a vacuum vessel to a high vacuum; and an oil pump provided in series with the turbo-molecular pump. A rotary pump, a container vacuum gauge for measuring the degree of vacuum in the vacuum vessel, and an exhaust vacuum gauge for measuring the degree of vacuum at the inlet of the turbo molecular pump,
Control means for controlling the operation of the turbo-molecular pump and the opening and closing of an inlet valve of the turbo-molecular pump in accordance with the measured values of the container vacuum gauge and the exhaust vacuum gauge is provided.

Further, in the starting method of the vacuum evacuation apparatus according to the present invention, when the vacuum evacuation apparatus having the above configuration is started, when the container vacuum gauge and the exhaust vacuum gauge indicate the atmospheric pressure, the oil rotary pump is operated. At the same time, the inlet valve of the turbo molecular pump is opened, and after the container vacuum gauge and / or the exhaust vacuum gauge have reached the turbo molecular pump operable pressure, the turbo molecular pump is operated, and the container vacuum gauge When the pressure is low and the pressure is higher than the turbo molecular pump operable pressure, the oil rotary pump is first operated and the exhaust vacuum gauge shows the same pressure as the container vacuum gauge, and then the inlet valve of the turbo molecular pump is opened. After the container vacuum gauge and / or the exhaust vacuum gauge reach a turbo molecular pump operable pressure, the turbo molecular pump is operated,
When the container vacuum gauge indicates a pressure equal to or lower than the turbo molecular pump operable pressure, first, the oil rotary pump is operated to set the exhaust vacuum gauge to the turbo molecular pump operable pressure, and then the turbo molecular pump is operated. Further, after the evacuation vacuum gauge shows the same pressure as the container vacuum gauge, the inlet valve of the turbo molecular pump is opened to evacuate the vacuum container to a desired degree of vacuum.

[0013]

[Operation] According to the above configuration, the exhaust system including the turbo-molecular pump and the oil rotary pump is integrated into one, and the apparatus configuration is simplified, and the pressure in the container and the pressure of the exhaust system are grasped. The device can be started and restarted while preventing oil contamination and the like. In addition, the control means can automatically start and restart according to the pressure in the container.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail based on one embodiment shown in FIG.

FIG. 1 is a system diagram showing an embodiment of a vacuum evacuation apparatus of the present invention. A turbo-molecular pump 13 is connected to a vacuum vessel 11 through an inlet valve 12 in the same manner as in the prior art. A container vacuum gauge 14 is mounted, and an atmospheric pressure return valve 15 is provided.

On the outlet side of the turbo molecular pump 13,
Oil rotary pump 17 connected in series via exhaust valve 16
And an atmospheric pressure return valve 18, and an exhaust vacuum gauge 19 is provided on the inlet side of the turbo-molecular pump 13.

Then, according to the measured values of the container vacuum gauge 14 and the exhaust vacuum gauge 19, the turbo molecular pump 13,
A control means 20 for controlling both of the oil rotary pumps 17 and the inlet valve 12 and the exhaust valve 16 is provided.

Hereinafter, an example of the method of the present invention will be described together with the operation of the control means with reference to FIG.

First, the procedure for starting the apparatus is as follows. When the inside of the vacuum vessel 11 and the exhaust system are at atmospheric pressure. . When the pressure inside the vacuum vessel 11 is lower than the atmospheric pressure and exceeds the operable pressure of the turbo molecular pump, for example, 0.1 Torr. . When the pressure inside the vacuum vessel 11 is equal to or lower than the operable pressure of the turbo molecular pump. Can be considered. In this, is the normal startup procedure,
, Is the restart procedure.

In FIG. 2, first, at step S1
To operate (ON) the oil rotary pump 17 (RP) and open the exhaust valve 16 (V1). Next, in step S2, the measured value P1 of the container vacuum gauge 14 is compared with the atmospheric pressure,
If the measured value P1 is lower than the atmospheric pressure, the process proceeds to step S3. If the measured value P1 is the atmospheric pressure, the process proceeds to step S5.
To open the inlet valve 12 (V2). Then, in step S6, the measured value P2 of the evacuation vacuum gauge 19 is compared with the turbo molecular pump operable pressure Ps.
If rr or less, the process proceeds to step S7, where the turbo molecular pump 13 (TMP) is operated to evacuate the vacuum vessel 11 to a high vacuum.

At the time of starting, since the suction side of the oil rotary pump 17 is at atmospheric pressure, even if the inlet valve 12 and the exhaust valve 16 are opened, oil and oil vapor do not flow toward the vacuum vessel 11 and oil contamination occurs. There is no. Further, the turbo molecular pump 13 starts operating after the pressure in the system becomes 0.1 Torr or less, so that it is not damaged.

On the other hand, in step S3, when the measured value P1 of the container vacuum gauge 14 is lower than the atmospheric pressure and is higher than the turbo molecular pump operable pressure Ps, that is, in the above case,
In step S4, the values of the two vacuum gauges are compared, and the exhaust vacuum gauge 1
After the measured value P2 of 9 falls below the measured value P1 of the container vacuum gauge 14, the process proceeds to step S5, and the inlet valve 12 (V2) is opened. Thereafter, from step S5, the same procedure as described above is performed.

At the time of this restart, the inlet valve 12 (V2) for separating the inside of the vacuum vessel 11 from the exhaust system is opened after the pressure of the exhaust system falls below the pressure in the vacuum vessel 11, so that the oil rotary pump 17 Oil and the like can be prevented from flowing into the vacuum vessel 11. Also, as in the case of (1), the turbo molecular pump 13
Can also be prevented from being damaged.

In step S3, the container vacuum gauge 14
Is smaller than the turbo molecular pump operable pressure Ps, that is, in the above case, the process proceeds to step S8, where the measured value P2 of the exhaust vacuum gauge 19 and the turbo molecular pump operable pressure Ps are When P2 becomes equal to or less than Ps, the routine proceeds to step S9, where the turbo molecular pump 13 (TMP) is operated. Then, step S10
In step S11, if P2 becomes equal to or smaller than P1,
To open the inlet valve 12 (V2).

At this time, the exhaust system is sufficiently evacuated and the inlet valve 12 is opened in the same manner as described above, so that the oil from the oil rotary pump 17 can be prevented from flowing into the vacuum vessel 11.

As described above, by controlling each pump and valve based on the pressure in the vacuum vessel 11 and the pressure in the exhaust system, even if the apparatus is stopped during the evacuation or during the test, the power failure can be prevented. Even when the apparatus is stopped for example, there is no need to once return the inside of the container to the atmospheric pressure unlike the related art, and the apparatus can be easily restarted without causing oil contamination.

[0027]

As described above, according to the present invention,
The vacuum exhaust system can be simplified, start-up and restart can be performed while preventing oil contamination, and fully automatic operation of the vacuum exhaust system is also possible, thus reducing equipment costs and improving workability. it can.

[Brief description of the drawings]

FIG. 1 is a system diagram showing one embodiment of a vacuum exhaust device of the present invention.

FIG. 2 is a flowchart illustrating an example of an operation of a control unit.

FIG. 3 is a system diagram showing an example of a conventional evacuation device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Vacuum container 12 ... Inlet valve 13 ... Turbo molecular pump 14 ... Container vacuum gauge 16 ... Exhaust valve 17
... Oil rotary pump 19 ... Exhaust vacuum gauge 20 ... Control means

Continuation of the front page (56) References JP-A-2-107775 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F04B 37/16 F04D 19/04

Claims (3)

(57) [Claims] A turbo-molecular pump for evacuating the vacuum vessel to a high vacuum; an oil rotary pump provided in series with the turbo-molecular pump; a vessel vacuum gauge for measuring the degree of vacuum in the vacuum vessel; A vacuum gauge for measuring the degree of vacuum at the inlet of the turbo-molecular pump, and operates the turbo-molecular pump and opens and closes the inlet valve of the turbo-molecular pump according to the measured values of the container vacuum gauge and the vacuum gauge. An evacuation apparatus characterized by comprising control means for controlling. 2. When starting the evacuation apparatus according to claim 1, when the container vacuum gauge and the exhaust vacuum gauge indicate an atmospheric pressure, the oil rotary pump is operated and simultaneously the inlet of the turbo molecular pump. The valve is opened, and after the container vacuum gauge and / or the exhaust vacuum gauge have reached the turbo molecular pump operable pressure, the turbo molecular pump is operated. The container vacuum gauge is lower than the atmospheric pressure, and the turbo molecular pump operable pressure. When indicating a higher pressure, first, the oil rotary pump is operated, and the exhaust vacuum gauge shows the same pressure or lower pressure as that of the container vacuum gauge, and then the inlet valve of the turbo molecular pump is opened, and the container is further opened. After the vacuum gauge and / or the evacuation vacuum gauge reach the turbo molecular pump operable pressure, the turbo molecular pump is operated, and the container vacuum gauge is operated by the turbo molecular pump When the pressure is equal to or lower than the allowable pressure, the oil rotary pump is first operated to set the exhaust vacuum gauge to a pressure at which the turbo molecular pump can be operated, and then the turbo molecular pump is operated. A starting method of a vacuum pumping device, characterized in that after showing the same pressure or a lower pressure, an inlet valve of the turbo-molecular pump is opened and the inside of the vacuum vessel is evacuated to a desired degree of vacuum. 3. The starting method of a vacuum exhaust device according to claim 2, wherein the control unit performs the starting procedure by automatic control.