JPH01178787A - Switching trap device for vacuum pump - Google Patents

Abstract

PURPOSE:To well maintain oil traps without disassembling them by connecting a piping system for introducing a high temperature discharge gas from a vacuum pump to a trap being out of operation such that the lines may be switched. CONSTITUTION:A discharge gas from a vacuum pump is introduced from a discharge port 9 through a discharge gas introducing pipe 10 into oil traps 4, 5. When the trap 5 is out of operation, the discharge gas flows through the oil trap 5 in the direction of the arrow. The high temperature discharge gas introduced into the oil trap 5 evaporates the oil absorbed in the oil-absorbent, and the evaporated oil is discharged through a pipe line 14 outside the machine. Switching the introduction of the high temperature discharge gas into the oil traps 4, 5 is performed by change-over of three-way valves 11, 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a switchable trap device for a vacuum pump, and in particular to a vacuum pump suitable for regenerating oil adsorbent in an oil trap without stopping the machine. This invention relates to a switchable trap device.

[Prior Art] Generally, in order to realize a vacuum pump with clean exhaust, it is necessary to prevent lubricating oil from leaking from each bearing chamber to the compression working chamber. Therefore, a method has been adopted in which the bearing chamber and the suction port are connected via piping through an oil trap to reduce the pressure difference by one inch.

For example, in the roots-type vacuum pump described in Japanese Patent Publication No. 50-30285, lubricating oil flowing out from the shaft seal is collected in an oil reservoir by the action of an inclined shoulder and a right-angled shoulder surface provided on the rotating shaft. The oil is collected by natural flow due to the pressure difference into an oil trap that is piped to open on the suction side.

Further, for example, in the shaft sealing device for a screw vacuum pump described in Japanese Patent Application Laid-open No. 62-197685, a single shaft sealing device equipped with an oil adsorbent is installed between the suction side bearing chamber equipped with an oil storage tank and the suction port. They are communicated via piping with an oil trap, but no consideration has been given to the fact that the oil trap's functionality deteriorates in a relatively short period of time.

[Problems to be Solved by the Invention] The above-mentioned conventional technology does not take maintenance of the oil trap into consideration, and when the function of the oil adsorbent deteriorates, there is a problem in that the vacuum pump must be stopped in order to replace it. was there.

The present invention was made in order to solve the problems of the prior art described above, and enables maintenance of the oil trap without stopping the vacuum pump or disassembling the oil trap, significantly reducing maintenance costs. It is an object of the present invention to provide a switchable trap device for a vacuum pump that can be used.

[Means for Solving the Problems] In order to achieve the second object, the configuration of the vacuum pump switching type trap device according to the present invention is such that the vacuum pump has a suction side bearing chamber equipped with an oil storage tank, a suction port, During this period, a plurality of traps equipped with oil adsorbents are connected via piping so that they can be switched and used using flow path switching valves, and a piping system that conducts the high temperature discharge gas of the vacuum pump is connected to the traps that are inactive. They are connected in a switchable manner.

In addition, the purpose of ``2'' is to make the trap a double configuration, use a switching valve to switch between laps 1 and 1, and pass the discharged gas through the unused lap 1 to raise the temperature to adsorb it on the oil adsorbent. This is achieved by evaporating the existing oil and regenerating the oil sorbent.

[Effect] The function of the above technical means is as follows.

In one trap, the oil adsorbent inside it adsorbs the diffusing oil molecules and prevents the oil from spreading and backflowing. Once this function has degraded, a switch valve switches to a new trap. By applying heat to the adsorbent material that has adsorbed oil, the oil evaporates and the adsorbent's ability to adsorb oil is restored.

On the other hand, due to the high compression ratio, the vacuum pump discharge gas temperature is the temperature required to evaporate the oil (for example, 200 to 25
0℃), and this high temperature gas is used to regenerate the oil adsorbent (
It is possible to restore function.

[Example code] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

The drawing is a schematic configuration diagram of a switching type trap device for a screw vacuum pump according to an embodiment of the present invention.

In the drawings, 1 is a working chamber of the screw vacuum pump body, 2 is a suction side bearing chamber equipped with an oil storage tank (not shown), 3 is a suction port formed in the screw vacuum pump body, and 4 and 5 are suction ports formed in the screw vacuum pump body. , an oil trap related to a plurality of traps (in this case, a double configuration), these oil traps 4 and 5.
Although not particularly shown, the container is equipped with a commercially available spherical or cylindrical oil adsorbent that is filled into the container through a mesh-like partition.

6 is a communication pipe connecting the oil traps 4 and 5 between the suction side bearing chamber 2 and the suction port 3 so that the oil traps 4 and 5 can be switched and used by a flow path switching valve; 7 and 8 are related to the flow path switching valve; It is a three-way valve.

Reference numeral 9 denotes a discharge port 1 formed in the screw vacuum pump body; 10 denotes a discharge gas introduction pipe for conducting the high temperature discharge gas of the screw vacuum pump to the oil traps 4 and 5 in a switchable manner; 11°12 13 is a discharge side bearing and a gear chamber; and 14 is a pipe for discharging oil.

The configuration of the switching trap device for the screw vacuum pump shown in the drawings and the effects associated with the configuration will be explained in more detail.

Although not shown here, a screw vacuum pump includes a pair of male and female screw rotors that mesh with each other and are housed in a casing so as to maintain a minute gap to form a working chamber 1, a suction side bearing chamber 2, a discharge side bearing, and a gear chamber. 13, gas is sucked into the working chamber 1 from the suction port 3, compressed, and discharged from the discharge port 9.

Lubricating oil for lubricating the bearing is stored in the suction side bearing chamber 2, and the suction side bearing chamber 2 and the working chamber 1 are sealed with a non-contact screw seal.

At startup, in order to quickly reduce the pressure in the suction side bearing chamber 2 to a vacuum and then maintain a constant pressure difference with the suction port 3, the suction side bearing chamber 2 and the suction port 3 are generally equipped with an oil I-wrap. 4 and are connected by a communication pipe 6. The pressure in the suction side bearing chamber 2 is higher than that in the suction ports 1-3, and gas containing oil mist constantly flows to the suction port 3 via the oil I-wrap 4. This amount will further increase. For this reason, it is difficult to operate continuously for a long time with only one oil trap 4 as in the conventional case. Therefore, as shown in the drawing, if the oil 1 to lap are double-configured, and the white parts of the three-way valves 7 and 8 are open and the black parts are closed, as shown in the figure, the gas will flow as shown by the arrow. , the oil trap 4 is alive, and the other oil trap 5 is at rest with no gas flowing.

Incidentally, the oil traps 4 and 5 are filled with an oil adsorbent that has the effect of adsorbing oil mist, but if the function of this oil adsorbent deteriorates, oil mist l- will enter the suction port 3, causing the vacuum pump to performance and has an adverse effect on exhaust screenability.

In order to keep the function of this oil adsorbent always above a certain level, it is possible to replace the above-mentioned inactive oil adsorbents for oils 1 to 5 with new ones, but here we will use the high temperature discharge gas of the vacuum pump. By evaporating the oil adhering to the oil adsorbent in the oil trap 5 and regenerating the oil adsorbent, there is no need to replace it.

The oil l-wraps 4 and 5 are switched by switching the flow paths of the three-way valves 7 and 8.

The discharge gas of the vacuum pump is introduced into the oil traps 4 and 5 from the discharge port 9 through the discharge gas introduction pipe 10. When the oil trap 5 shown in the drawing is at rest, the discharged gas flows through the oil trap 5 as shown by the arrow.

The white part of the three-way valves 11 and 12 indicates open, and the black part indicates closed. The high temperature discharge gas introduced into the oil trap 5 evaporates the oil adsorbed on the oil adsorbent, and the evaporated oil is discharged outside the machine via the plumber 4.

Switching to introduce this high-temperature discharged gas into the oil 1 to the wraps 4 and 5 is performed by switching the flow paths of the three-way valves 11 and 12.

The flow path switching of the three-way valves 7 and 8 is to switch between activation and deactivation of the traps 4 and 5 in the communication pipe 6 system, and the three-way valve 11
．． The flow path switching 12 is for switching the oil adsorption function of the traps 4 and 5 in the discharge gas introduction pipe 10 system, and the flow paths are opened and closed in a mutually determined relationship. Therefore, if a control circuit is configured in advance to automatically switch the flow paths of these three-way valves every predetermined operating time, automation of flow path switching can be easily implemented.

According to this implementation, without stopping the vacuum pump,
You can maintain the oil trap, and if the oil trap is inactive, it can be regenerated using the discharge gas from the vacuum pump.

This has the effect of significantly extending the maintenance period and reducing maintenance costs.

In the above-mentioned embodiment, an example of a switching type I-lap device in a screw vacuum pump was explained, but the present invention is not limited to a screw vacuum pump, and can be applied to other types as long as the same effect can be achieved. It can also be applied to other vacuum pumps.

[Effects of the Invention] As explained below, according to the present invention, it is possible to maintain the oil trap without stopping the vacuum pump or disassembling the oil trap, thereby significantly reducing maintenance costs. It is possible to provide a switchable trap device for a vacuum pump that can be used.

[Brief explanation of the drawing]

The drawing is a schematic configuration diagram of a switching type trap device for a screw vacuum pump according to an embodiment of the present invention. 1. Working chamber, 2. Suction side bearing chamber, 3. Suction port, 4, 5. Oil trap, 6. Communication pipe, 7゜8.11.12... Three-way valve, 9 ...Discharge port, 1
0...Discharge gas introduction pipe. 2... α end E1 mu A series bearing chamber 6, Tsuchitsu Ao 70... gt-gas introduction π

Claims (1)

[Claims] 1. In a vacuum pump, between the suction side bearing chamber equipped with an oil storage tank and the suction port, a plurality of traps equipped with an oil adsorbent are connected via piping so that they can be switched and used using a flow path switching valve, and 1. A switchable trap device for a vacuum pump, characterized in that a piping system through which high-temperature gas discharged from the vacuum pump is conducted is connected to the trap in a switchable manner.