JP2000337291A - Exhaust system for semiconductor manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily monitor the counterflow of a liquid such as a drain oil generated from the other pump by fitting a transparent monitoring pipeline to a motor exhaust pipeline of a dry turbo vacuum pump, and fitting a recovery pot for the oil or the like into a lower position of the monitoring pipeline. SOLUTION: When a pump is driven at a high speed, gas taken in from an intake port 6 is subjected to compression from a molecular flow pressure area to an intermediate flow pressure area by a centrifugal compression pump stage 4a and compression in a viscous flow pressure area by a circumferential flow compression pump stage 4b and exhausted to a customer side main duct 19 from a discharge port 12 through a pipeline 17. At this time, a lubricating oil 29 in an oil tank 21 is supplied to pump bearings 7a, 7b, and shaft sealing N2 gas is supplied from an N2 gas line 22. In this case, a drain oil monitoring pipeline 15 is fitted behind an oil mist filter 16 inside an N2 gas exhaust pipeline 18 connected to a main duct 19. The counterflow of the oil generated in the other pump can thereby be confirmed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust pipe for a motor chamber of a dry turbo vacuum pump and a discharge port of a pump, and is provided with a mechanism for monitoring and preventing a backflow of liquid such as drain oil into the pump, thereby preventing the drain oil or the like from flowing. The present invention relates to a technique for preventing adverse effects such as pump stoppage due to backflow of liquid.

[0002]

2. Description of the Related Art As a known example of this type of pump, Japanese Patent Application Laid-Open
There is JP-A-6-222969. A housing having an intake port and an exhaust port, a rotating shaft rotatably supported in the housing, and a multi-stage circumferential flow impeller supported by the rotating shaft;
A stator forming a multi-stage circumferential flow pump together with the circumferential flow impeller in the housing; a centrifugal pump on an intake side of the circumferential flow pump is disposed; Turbo vacuum pump for exhausting air from the exhaust port to the atmosphere, the shaft sealing N2 filled in the pump
The gas (or dry air or the like) is exhausted to a customer side duct through a motor room exhaust pipe. In addition, the gas sucked from the inlet is compressed in the molecular pressure range from the molecular pressure range by the centrifugal compression pump stage and is compressed in the viscous flow range by the circumferential flow compression pump stage. It is exhausted to the side duct.

[0003]

In the prior art, N2 gas (or dry air or the like) filling the pump is discharged to a customer side line. In recent years, liquid such as drain oil generated from another pump has been used. In some cases, the gas enters the pump through the exhaust pipe of the motor chamber, and this has been found to be one of the causes for stopping the pump.

In some cases, liquid such as drain oil generated from another pump flows back into the pump from the pump discharge port. The customer is informed of the precautions in piping work, and is trying to prevent problems in the piping work.However, due to the small size and compactness, the customer's piping is unreasonable. When the liquid flows back into the pump as a liquid, the overload occurs. Therefore,
In recent years, it has been found that it is necessary for the pump side to monitor and prevent backflow of liquid such as oil to the pump.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a motor vehicle exhaust pipe in which drain oil flows backward from a customer side and a monitoring mechanism and a prevention mechanism for drain oil reverse flow in a pump discharge pipe in order to engage with a customer. To prevent adverse effects such as pump stoppage.

[0006]

The disadvantages as described above are as follows.
By attaching a transparent monitoring pipe for visual confirmation to the motor exhaust pipe, it is easy to cause oil or the like discharged from another pump to flow backward. Also, by attaching a pot for collecting oil etc. at a position below this monitoring pipe,
Liquid such as drain oil discharged from another pump can be easily collected.

[0007] The backflow of drain oil is not abrupt,
Since it tends to flow backward gradually over a long period of time, it is possible to perform good and reliable monitoring and prevent drain oil from flowing into the pump by installing a simple monitoring device such as a transparent pipe. .

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, an intermediate portion and a lower end portion of a shaft 3 are supported by rolling bearings 7a and 7b, and a high-frequency motor rotor 8a is press-fitted between the bearings. The rotor 1 of the multistage circumferential compression pump stage 4b and the centrifugal compression pump stage 4a is press-fitted into the upper side of the shaft 3. A stator 2 is disposed with respect to the rotor 1.
A suction casing 5 having a pump inlet 6 formed therein is attached to an upper portion of the suction casing 5. On the outer periphery of the stator 2, there is a cooling jacket 9 for removing heat generated by the pump action. On the other hand, the motor stator 8b is held by the motor casing 10. The motor casing 10 has a motor cooling jacket 11.

The operation of the present pump will be described. When the pump is driven at a high speed based on a command from a control device (not shown), the gas sucked in from the suction port 6 is compressed by the centrifugal compression pump stage 4a from the molecular flow pressure region to the intermediate flow pressure region and the circumferential flow compression pump stage. 4b, the fluid is compressed in the viscous flow pressure range,
Then, the air is exhausted to the customer side main duct 19 through the discharge side pipe 17.

A lubricating oil 29 is supplied to the rolling bearings 7a and 7b of the pump from an oil tank 21 below the pump by an oil pump (not shown). The lubricating oil 29 supplied to the rolling bearing 7a is freely dropped, and
And returns to the oil tank 21. In addition, the rolling bearing 7b
The lubricating oil 29 supplied to the oil tank 21
Return to

The lubricating oil 29 supplied to the rolling bearing 7a is controlled so as not to flow into the circumferential compression pump stage 4b.
N2 gas (or dry air) for shaft sealing is supplied from the two gas lines 22. If the pressure of the N2 gas is too high, it is exhausted unnecessarily, so that the N2 gas is supplied at a pressure slightly higher than the supply pressure of the lubricating oil. The N2 gas flows into the lubricating oil side so that the lubricating oil does not enter the inside of the pump, and enters the motor chamber 20 side. Since the pressure in the motor chamber is increased by the N2 gas, a motor chamber exhaust pipe 13 is provided as the exhaust gas.

The exhaust gas is separated through an oil mist filter 16 into oil smoke and N2 gas emitted from the motor chamber, and lubricating oil is recovered as drain oil. The drain oil returns to the oil tank 21 through the drain return pipe 14. The N2 gas is exhausted to the main duct 19 through the N2 gas exhaust pipe 18.

The main duct 19 is provided with a motor chamber exhaust pipe 26 from a plurality of other pumps 25.
The flue gas 27 from the plurality of pumps is
Is cooled in the drain oil 28 and flows back to the N2 gas exhaust pipe 18 of the turbo vacuum pump, so that the transparent drain oil monitoring pot 15 receiving the drain oil 28
Is attached after the oil mist filter 16 when viewed from the pump, so that it is possible to easily monitor that the oil that has not come out of the pump and flows from the main duct 19.

FIG. 2 shows a drain oil recovery pot 23 attached below the drain oil monitoring pot 15 so that the drain oil 28 flowing backward from the customer side main duct 19 does not enter the oil mist filter 16. Drain oil is one in which oil smoke generated from another pump cools down and gradually flows in. Therefore, the drain oil recovery pot 23
Can be a compact one that is capacitive. In addition, the drain oil 28 can be collected by attaching a valve 30 to the drain oil collection pot 23 so that the drain oil can be taken out when the drain oil has accumulated to some extent.

Also, the drain oil monitoring pot 15 is controlled so that the drain oil 28 does not enter the oil mist filter 16.
The oil mist filter 16 is prevented by attaching the pipe obliquely.

The pump outlet 1 is connected to the discharge side pipe 17 in FIG.
In order to prevent the drain oil 28 on the customer side from flowing back to 2, the drain oil 28 can be provided by attaching the drain pot 24. Also, by attaching a valve 31 to the drain pot 24 so that the drain oil can be taken out when the drain oil has accumulated to some extent, the drain oil 28 can be collected.

Here, the exhaust of a general semiconductor manufacturing apparatus will be described with reference to FIG. Usually, the semiconductor manufacturing apparatus 32
Is provided with several vacuum pumps 33, and exhausts gas generated in the semiconductor manufacturing process through the suction port piping 34 from the suction / discharge side pipe 17 to the main duct 19. As shown in FIG. 3, exhaust pipes are provided in the main duct by a plurality of vacuum pumps 33. For this reason,
There is a possibility that drain oil or the like may flow into a normal vacuum pump, and the present invention is effective.

[0018]

According to the present invention, the liquid such as oil mist drain oil discharged from another pump and water equivalent thereto generated in the customer main duct easily flows back into the turbo vacuum pump. Can be monitored. This eliminates the problem that the pump or the like is overloaded due to oil or the like entering the inside of the pump, and the pump can be used for a long time.

Further, when the drain oil of the oil mist discharged from another pump generated in the main duct and a liquid such as water equivalent thereto flow back into the turbo vacuum pump, it is easily prevented from flowing into the pump. I can do it.

In the case where the drain oil generated in the main duct and the liquid such as water are substances having an adverse effect on the human body or the like, the adverse effect on the pump can be prevented only by replacing the monitoring pipe.

When the drain oil generated in the main duct and the liquid such as water flow back into the turbo vacuum pump, if the lubricating oil in the pump is different from the pump, the pump must be disassembled and cleaned. This is time consuming and expensive, but with the present invention, this concern is not required.

[Brief description of the drawings]

FIG. 1 is a sectional view of an exhaust system of a semiconductor manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view of an exhaust system of a semiconductor manufacturing apparatus according to another embodiment of the present invention.

FIG. 3 is a diagram illustrating an exhaust system of a general semiconductor manufacturing apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... rotor, 2 ... stator, 3 ... shaft, 4a ... centrifugal compression pump stage, 4b ... circumferential compression pump stage, 5 ... suction casing, 6 ... intake port, 7a ... bearing, 7b ... bearing, 8a
... Motor rotor, 8b ... Motor stator, 9 ... Cooling jacket, 10 ... Motor casing, 11 ... Cooling jacket, 12 ... Discharge port, 13 ... Motor room exhaust pipe, 14 ... Drain return pipe, 15 ... Drain oil monitoring pot, 16 ...
Oil mist filter, 17 ... Discharge side piping, 18 ... N2
Gas exhaust pipe, 19: Main duct, 20: Motor room,
21: Oil tank, 22: N2 gas line, 23: Drain oil recovery pot, 24: Drain pot, 25: Other pump, 26: Motor exhaust pipe of another pump, 27: Exhaust gas exhausted from another pump , 28 ... drain oil exhausted from another pump, 29 ... lubricating oil, 30 ... valve, 31 ... valve, 32 ... semiconductor manufacturing equipment, 33 ... vacuum pump, 34 ... suction port piping.

Claims (3)

[Claims] 1. A semiconductor manufacturing apparatus according to claim 1, wherein a liquid such as drain oil generated from another pump flows backward through a motor chamber exhaust pipe of a dry turbo vacuum pump. Exhaust system. 2. The semiconductor manufacturing method according to claim 1, wherein a liquid such as drain oil generated from another pump is prevented from flowing back into the pump through a motor chamber exhaust pipe of the dry turbo vacuum pump. Equipment exhaust system. 3. A semiconductor manufacturing apparatus according to claim 1, wherein a liquid such as drain oil generated from another pump is prevented from flowing backward through the discharge port of the dry turbo vacuum pump and entering the inside of the pump. Exhaust system.