KR101003247B1 - A filter all supplemtary inhalation pump of Sulfur Hexafluoride gas liquefaction turnaround device - Google Patents

Abstract

The present invention relates to a filter-integrated auxiliary suction pump of the SF ₆ gas recovery device, wherein the auxiliary suction pump has a space in which the oil removal filter is placed, and a first female screw is formed at one side of the auxiliary suction pump. A side having an inlet having an inlet into which the oil removal filter is inserted, the space being placed in the space of the settlement, one side of which is opened, and an insertion hole formed at the other side, and an oil removal filter for removing oil remaining in the SF ₆ gas; , One end is formed with a first male screw is fastened to the first female screw, the second female screw is formed at the center of the other end, the connecting portion is formed in the center of the annular jaw extending in the circumferential direction, one end is the second connecting portion It is fastened to the female screw, and the other end flows into the open side of the oil removal filter, flows out into the insertion hole formed on the other side, and is fastened by a nut to be connected to the oil removal filter. It is coupled to the entrance of the settled portion, the bolt rod to be firmly fixed, the support for supporting the lower end of the other side of the oil removal filter in order to prevent the other side of the oil removal filter is tilted downward or shaken by the operation of the device, that is as a check valve to prevent a third female thread and a cover, the SF ₆ gas is formed in the inlet from entering the SF ₆ gas inlet is formed to be engaged with the pipe of the flow channel is countercurrent to the laden state of the oil,

By installing a built-in separately oil removing filter, which is installed in a flow path inside the auxiliary suction pump, an oil removing filter is provided on the flow path due to air introduction and SF ₆ gas flow generated in the connecting portion of the oil removing filter SF ₆ There is an effect that can prevent problems such as gas purity, pipe pollution, environmental pollution, etc. in advance.

Further, SF ₆ gas by installing to prevent reverse flow of the SF ₆ gas flow into the inlet to the secondary suction pump inlet check valves, laden with the pipe is used as a flow path oil advance the problem of contamination by SF ₆ gas backflow There is an effect that can be prevented.

Auxiliary suction pump, oil removal filter, check valve, SF6 gas, GIS

Description

A filter all supplemtary inhalation pump of Sulfur Hexafluoride gas liquefaction turnaround device

The present invention relates to a filter-integrated auxiliary suction pump of the SF ₆ gas recovery device, and more specifically, by installing an oil removal filter installed separately on the flow path inside the auxiliary suction pump, the oil removal filter is installed on the flow path. purity lowering of the installation due to the air inlet and SF ₆ gas flow generated in the connecting portion of the oil removing filter SF ₆ gas, the filter of the SF ₆ gas recovery apparatus capable of preventing problems such as contamination of the pipe, and environmental pollution from occurring It relates to an integrated auxiliary suction pump.

In general, most of the GIS and some transformers, which are used in Korea, are gas insulation products using SF ₆ gas as an insulation medium. In particular, the GIS installed and operated in the substation uses a very large amount of SF ₆ gas.

SF ₆ gas, which is used as an insulating medium in such power equipment, has been widely studied for its physical and chemical properties, various gas discharge characteristics, and its use in the power industry. SF ₆ gas is chemically inert, nontoxic, flame retardant, non-explosive, and thermally stable at steady state. It has generally been regarded as an environmentally safe and acceptable substance in that it does not have a detrimental effect on other biological resources due to its relative inertness and nontoxicity. This gas exhibits a large electrical buoyancy effect even at room temperature and considerably higher than room temperature, and this electrical buoyancy effect results in high dielectric strength and excellent arc blocking, i.e., an arc extinguishing effect. Under atmospheric pressure, the breakdown voltage of SF ₆ gas is about three times that of air. Furthermore, the thermal breakdown voltage of SF ₆ gas is excellent.

In addition, most of the stable decomposition by-products not only contribute significantly to the dielectric strength reduction but can be removed by filtration, and the SF ₆ gas does not cause polymerization or flash carbon or conductive deposits during flashover, It is chemically compatible with most solid insulating and conductive materials used in electrical installations at temperatures up to.

In addition to these excellent insulation and thermal conductivity, SF ₆ gas has a relatively high pressure at room temperature when filled in a vessel. The liquefaction pressure of SF ₆ gas is about 2,100 kPa at 21 ° C, and its boiling point is -63.8 ° C, which is quite low, and the SF ₆ gas insulation facility is filled at 400-600kPa. This gas is easily liquefied by pressure at room temperature, whereby it can be compressed and stored in a metallic cylindrical container. This makes it easy to handle and use. As a result, the electrical industry has used SF ₆ gas in electrical installations and has long accumulated experience.

However, SF ₆ gas also has some bad properties: high discharge and highly corrosive compounds are formed upon discharge, from which non-polar contaminants such as air or CH ₄ , difficult to remove water vapor, conductive particles and conductor surface roughness Sensitivity to breakdown voltage, non-ideal gas behavior at very low temperatures depending on the surrounding environment, such as the partial liquefaction of SF ₆ gas at low temperatures. In addition, SF ₆ gas has a high infrared absorption ability and cannot be quickly removed from the earth's atmosphere because of its chemical inertness.

Because of these last two properties, SF ₆ gas is designated as a potential greenhouse gas, despite its chemical inertness having no effect on stratospheric ozone destruction.

As mentioned earlier, most of the GIS currently used in Korea and most power devices such as some transformers are gas-insulated products using SF ₆ gas as an insulating medium. In particular, the GIS installed and operated in the substation uses a very large amount of SF ₆ gas.

However, SF ₆ gas is colorless, odorless and harmless under normal conditions, but changes to harmful gas at the time of contact with fire, and it is also one of the representative environmental pollutants that cause global warming. Its use is regulated. As a result, there is a trend of developing and applying alternative insulating materials all over the world, but in the case of GIS, most countries in Korea and abroad still apply the insulation method using SF ₆ gas.

In case of 170kV GIS, inspect all the SF ₆ gas filled in the GIS after periodical inspection and discard the collected SF ₆ gas in fear of deterioration of insulation performance due to mixing of moisture and impurities. New gas is being injected. This phenomenon is the same not only in GIS expansion but also in GIS as well as inspection of SF ₆ gas insulated chargers such as switchgear and breaker, and disposal after replacement. This waste gas accelerates environmental pollution, as mentioned earlier.

Due to this situation, developed countries have developed and used recovery devices capable of reusing SF ₆ gas, and the development of reliable SF ₆ gas recovery devices is urgently needed to prevent environmental pollution in Korea.

In Korea, SF ₆ gas filled in most of GIS and some transformers such as transformers can be recovered more than 99%, and SF ₆ gas recovery is made by reusing the recovered SF ₆ gas into power equipment and reusing it. The device was developed.

The SF ₆ gas recovery apparatus includes a storage tank 2 in which SF ₆ gas, which is an insulating medium gas filled in the GIS 1, is recovered and stored as shown in FIG. 1, the GIS 1, and A vacuum pump 3 installed for vacuum and injection of the storage tank 2, a semi-sealed compressor 4 for differentially recovering SF ₆ gas in the GIS 1 to the storage tank 2, and the semi-sealed type A filter unit 5 including a dry filter for removing oil, dust and water remaining in the SF ₆ gas recovered by the compressor 4, a gas filter, an oil filter and a dust removing filter, and the semi-sealed compressor 4 Auxiliary suction pump ₆ for recovering the SF ₆ gas in the GIS (1) and the oil removal filter (7) for removing the oil remaining in the SF ₆ gas recovered by the auxiliary suction pump (6) ), a refrigeration unit (8) for liquefying the SF ₆ gas recovered in the storage tank (2), the refrigerating unit (8) And a heating unit (9), a passage (10) having one or more valves, and connect each of the components, the semi-hermetic compressor 4 and the auxiliary suction pump (6) for gasifying the SF ₆ liquid through, Controls the output of the vacuum pump 3, the freezing section 8 and the heating section 9 and manages the temperature of the storage tank 2, while automatically recovering and recharging the remaining SF ₆ gas in the GIS 1 It is configured to include a control unit (not shown) for determining the operating state of the.

However, after flowing into the auxiliary suction pump 6 in which the oil 6a for lubricating and sealing is incorporated, the oil removal filter 7 for removing the softness remaining in the outgoing SF ₆ gas is provided in the flow path 10. ) Is coupled to each other separately, the outside of the air is mixed through the damage of the coupling portion or the occurrence of fine gaps, there is a problem that the purity of the SF ₆ gas is reduced, which causes the pipe used as the flow path (10) This contamination or SF ₆ gas leaked there was a problem that causes environmental pollution.

In addition, the SF ₆ gas introduced into the auxiliary suction pump often flows back in a state containing oil, thereby contaminating the pipe used as the flow path 10.

The present invention has been proposed to solve the above problems, the object is to install the oil removal filter installed separately on the flow path inside the auxiliary suction pump, the oil removal filter is installed on the flow path purity degradation of the SF ₆ gas from the air inlet and the SF ₆ gas flow generated in the connecting portion of the oil removing filter, filter-one auxiliary of SF ₆ gas recovery apparatus capable of preventing problems such as contamination of the pipe, and environmental pollution from occurring In providing a suction pump.

Further, SF ₆ gas by installing to prevent reverse flow of the SF ₆ gas flow into the inlet to the secondary suction pump inlet check valves, laden with the pipe is used as a flow path oil advance the problem of contamination by SF ₆ gas backflow It is to provide a filter-integrated auxiliary suction pump of the SF ₆ gas recovery device that can be prevented.

The filter integrated auxiliary suction pump of the SF ₆ gas recovery device according to the present invention for achieving the above object, the storage tank in which the SF ₆ gas, which is an insulating medium gas filled in the GIS is recovered and stored, and the GIS and A vacuum pump installed for vacuum and injection of a storage tank, a semi-hermetic compressor for differentially recovering SF ₆ gas in the GIS to the storage tank, and oil and dust remaining in the SF ₆ gas recovered by the semi-hermetic compressor. And a filter unit including a dry filter, a gas filter, an oil filter, and a dust removal filter for removing moisture, an auxiliary suction pump for recovering SF ₆ gas in the GIS by assisting the semi-hermetic compressor, and the auxiliary suction pump. and an SF ₆ oil removal filter for removing the oil remaining in the gas collected by, and a refrigeration unit for liquefying the SF ₆ gas recovered in the storage tank, wherein A heating section for vaporizing the liquefied SF ₆ through the freezing section, a flow passage having one or more valves and connecting the respective components, the semi-sealed compressor, an auxiliary suction pump, a vacuum pump, a freezing section, and a heating section. In the SF ₆ gas recovery device comprising a control unit for controlling the output and managing the temperature of the storage tank and at the same time determine the operating state of automatic recovery and recharging of the remaining SF ₆ gas in the GIS,

The oil removal filter has a space to be settled, the first female screw is formed on one side, and the other side having an inlet having an inlet into which the oil removal filter is inserted, is placed in the space of the settlement, one side is open, the other side An insertion hole is formed, an oil removal filter for removing the oil remaining in the SF ₆ gas, and one end of the first male screw is formed to be engaged with the first female screw, a second female screw is formed in the center of the other end, A connecting portion having an annular jaw extending in the circumferential direction, one end is fastened to the second female screw of the connecting portion, the other end flows into the open one side of the oil removal filter flows out into the insertion hole formed on the other side is fastened by a nut And a bolt rod for firmly fixing the oil removal filter, and the other side of the oil removal filter is inclined downward or shaken by the operation of the device. To the support and, the inlet being coupled to the entrance of the placed parts, the center of which the cover is a third female thread which is engaged with the pipe of the conduit, the SF ₆ gas is introduced for supporting the lower end of the filter the other the oil removed to It is characterized in that it further comprises a check valve for preventing the flow of the SF ₆ gas is formed flows back to the state containing the oil.

As described above, according to the filter-integrated auxiliary suction pump of the SF ₆ gas recovery device according to the present invention, an oil removal filter installed separately on the flow path is installed in the auxiliary suction pump, so that the oil removal filter is installed on the flow path. It is installed to prevent the problems such as deterioration in purity of SF ₆ gas due to air inflow and SF ₆ gas outflow generated from the coupling portion of the oil removal filter, pollution of the pipe, environmental pollution.

Further, SF ₆ gas by installing to prevent reverse flow of the SF ₆ gas flow into the inlet to the secondary suction pump inlet check valves, laden with the pipe is used as a flow path oil advance the problem of contamination by SF ₆ gas backflow There is an effect that can be prevented.

Based on the accompanying drawings, the filter-integrated auxiliary suction pump of the SF ₆ gas recovery device according to a preferred embodiment of the present invention will be described in detail.

2 to 5 is that showing a filter-one auxiliary suction pump of SF ₆ gas recovery apparatus according to an embodiment of the present invention, Figure 2 is a filter-one auxiliary suction pump of SF ₆ gas recovery apparatus according to an embodiment of the present invention a conceptual diagram of the SF ₆ gas recovery apparatus comprising a, Figure 3 is a filter of the SF ₆ gas recovery apparatus shown in the perspective view of the SF ₆ gas recovery unit filter-one auxiliary suction pump shown in Figure 2, Figure 4 is a 3 5 is an exploded perspective view of the integrated auxiliary suction pump, and FIG. 5 illustrates AA cross-sectional views of the filter integrated auxiliary suction pump of the SF ₆ gas recovery device illustrated in FIG. 3.

As shown in the figure, the filter-integrated auxiliary suction pump 100 of the SF ₆ gas recovery device according to the embodiment of the present invention, SF ₆ gas which is an insulating medium gas filled in the GIS (1) is recovered A storage tank 2 to be stored, a vacuum pump 3 installed for vacuuming and injecting the GIS 1 and the storage tank 2, and SF ₆ gas in the GIS 1 to the storage tank 2; A semi-sealed compressor (4) for differential pressure recovery, a dry filter for removing oil, dust, and water remaining in the SF ₆ gas recovered by the semi-sealed compressor (4), a gas filter, an oil filter, and a dust removal filter. By the filter unit 5, the auxiliary suction pump 6 for recovering the SF ₆ gas in the GIS (1) by assisting the semi-sealed compressor 4, and the auxiliary suction pump (6) With an oil removal filter 7 for removing the oil remaining in the recovered SF ₆ gas, and the storage tank (2) A refrigeration section 8 for liquefying the recovered SF ₆ gas, a heating section 9 for vaporizing SF ₆ liquefied through the refrigeration section 8, a flow path including one or more valves and connecting the respective components. (10), the semi-sealed compressor (4), the auxiliary suction pump (6), the vacuum pump (3), the freezing section (8), the heating section (9) to control the output of the storage tank (2) In the SF ₆ gas recovery apparatus comprising a control unit (not shown) that manages the temperature of the control panel and determines an operating state of automatic recovery and recharging of the remaining SF ₆ gas in the GIS 1,

In the auxiliary suction pump 6, the settling unit 110, the oil removal filter 170, the connection unit 120, the bolt rod 130, the support 140, the cover 150, and the check valve It further comprises 160.

As shown in FIG. 5, the settlement unit 110 has a space 111 in which the oil removal filter 170 to be installed is placed, a first female screw 112 is formed at one side, and the oil at the other side. The removal filter 170 is configured to have an inlet 113 is inserted, it is preferable that the inlet 113 has a diameter of a size that can be inserted enough the oil removal filter 170.

Here, as shown in FIG. 5, an oil 6a for lubricating and sealing the auxiliary suction pump 6 is embedded in the inner bottom of the settling part 110, and through the auxiliary suction pump 6. The suctioned SF ₆ gas is introduced into the interior of the settling unit 110 through the communication hole 114 communicating the settling unit 110 and the auxiliary suction pump 6, and the introduced SF ₆ gas is primarily The impurities remaining after being transferred to the MR filter 12 are removed, and the remaining oil which is transferred to the oil removal filter 170 is secondarily removed.
That is, the oil removal filter 7 which is conventionally installed on the flow path 10, in the present invention, the settling portion (6) for storing the oil (6a) for lubricating and sealing the auxiliary suction pump (6) ( 110), by installing the built-in therein, the oil removing filter (7) with the prior installed on a flow path (10), SF ₆ gas from the air inlet and SF ₆ gas flow generated in the connecting portion of the oil removing filter (7) This is to prevent the problems such as lowering the purity, pollution of the pipe, environmental pollution in advance.
In addition, as shown in FIG. 4, the auxiliary suction pump 6 has a structure that is fixed to the settling unit 110 through the bolt coupling 13, but is not limited to this structure.
As shown in Figure 4 and 5, the oil removal filter 170 is placed in the space 111 of the settled portion 110, one side is open, the other side insertion hole 171 is formed SF _By removing the oil remaining in the ₆ gas, the SF ₆ gas from which impurities remaining in the demister filter 12 are first removed flows into the oil removal filter 170, and the oil remaining in the SF ₆ gas is secondary. Removed.

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As shown in FIG. 4, one end of the connecting portion 120 is formed with a first male screw 121 coupled to the first female screw 112, and a second female screw 122 is formed at the center of the other end thereof. The central portion is formed with an annular jaw 123 extending in the circumferential direction.

Here, the annular jaw 123 has a function of increasing the surface friction force so that the first male screw 121 and the first female screw 112 of the connecting portion 120 is fastened and firmly coupled, and is generally used. It is to function.

4 and 5, one end of the bolt rod 130 is fastened to the second female screw 122 of the connecting portion 120, the other end to the open side of the oil removal filter 170. Inflow and outflow into the insertion hole 171 formed on the other side of the oil removal filter 170 is fastened by a nut 131 to firmly fix the oil removal filter 170.

Here, as shown in FIG. 4, the bolt rod 130 extends in the circumferential direction of the bolt rod 130 to support the inner surface of the oil removal filter 170 to support the oil removal filter 170. It is preferable to install a support member 180 that supports the solid and prevents the shape change.

As shown in FIG. 5, the support 140 supports the lower end of the other side of the oil removal filter 170 to prevent the other side of the oil removal filter 170 from tilting downward or shaking due to the operation of the apparatus. Do it.

As shown in FIG. 4, the cover 150 is coupled to the inlet 113 of the settling unit 110, and a third female screw 151 is formed at the center thereof to be coupled to the pipe of the flow path 10. do.

Here, the cover 150 which is fastened to the inlet 113 of the settlement unit 110 is preferably fastened by the bolt 190.

As Figure 3 and shown in Figure 4, the check valve 160 to prevent the SF ₆ gas is formed in the inlet (11) flowing into the inflow SF ₆ gas to flow back to the state laden with oil, pipe This has the effect of solving the problem of being polluted.

That is, the filter-integrated auxiliary suction pump 100 of the SF ₆ gas recovery device of the present invention having the above structure has an oil removal filter 170 separately installed on the flow path 10 of the auxiliary suction pump 6. Since the oil (6a) is installed in the interior of the settled portion 110 is stored, the oil removal filter 7 is conventionally installed on the flow path 10 is generated in the coupling portion of the oil removal filter (7) There is an effect that can prevent the problems of the purity of SF ₆ gas, pollution of the pipe, environmental pollution due to air inflow and SF ₆ gas outflow.

The filter integrated auxiliary suction pump 100 of the SF ₆ gas recovery device according to an embodiment of the present invention having the configuration as described above is used as follows.

First, the operation principle of the SF ₆ gas recovery device will be described with reference to FIG. 2.

In order to recover the SF ₆ gas filled in the GIS 1, the inside of the storage tag 2 in which the SF ₆ gas recovered through the vacuum pump 3 is stored is in a vacuum state.

Then, the natural recovery proceeds through the differential pressure, and if the recovery is no longer possible through the differential pressure, the forced recovery is started using the semi-sealed compressor (4).

When forced recovery is performed using the semi-sealed compressor (4), about 80% of SF ₆ gas filled in the GIS (1) is recovered to the storage tank (2), and the auxiliary suction pump for recovering up to 99%. (6) should work.

Here, when the auxiliary suction pump 6 is operated as shown in FIG. 5, the SF ₆ gas sucked into the auxiliary suction pump 6 is introduced into the settling unit 110 with the oil therein, such oil being In order to remove the conventional oil removal filter (7) was installed on the flow path 10 in which the auxiliary suction pump 6 is installed, as described above, there were a number of problems caused by this.

That is, in order to solve the above-mentioned problems, the filter-integrated auxiliary suction pump 100 of the SF ₆ gas recovery device of the present invention includes an oil removal filter 170 separately installed on the oil passage 10 and the auxiliary suction pump ( By installing the oil 6a of 6) inside the settled portion 110 in which the oil 6a is stored, the oil removal filter 7 is conventionally installed on the flow path 10 so that the oil removal portion 7 at the coupling portion of the oil removal filter 7 is installed. It is possible to prevent problems such as deterioration in purity of SF ₆ gas, pollution of piping, and environmental pollution due to generated air inflow and SF ₆ gas outflow.

Although the present invention has been described with reference to the embodiments illustrated in the accompanying drawings, this is by way of example and not limited to the above-described embodiments, various modifications and equivalent embodiments are possible from those skilled in the art. You will understand the point. In addition, modifications by those skilled in the art can be made without departing from the scope of the present invention. Therefore, the scope of the claims in the present invention will not be defined within the scope of the detailed description, but will be defined by the following claims and their technical spirit.

1 is a conceptual diagram illustrating a conventional SF ₆ gas recovery device

2 is a conceptual diagram of a SF ₆ gas recovery device including a filter-integrated auxiliary suction pump of the SF ₆ gas recovery device according to an embodiment of the present invention.

3 is a perspective view of the filter-assisted auxiliary suction pump of the SF ₆ gas recovery device shown in FIG.

4 is an exploded perspective view of the filter-assisted auxiliary suction pump of the SF ₆ gas recovery device illustrated in FIG. 3;

FIG. 5 is a cross-sectional view taken along AA of the filter integrated auxiliary suction pump of the SF ₆ gas recovery device shown in FIG.

<Description of Symbols for Main Parts of Drawings>

1. GSI 2. Storage Tank

3. Vacuum pump 4. Semi-hermetic compressor

5. Filter part 6. Auxiliary suction pump

6a. Oil 7. Oil Removal Filter

8. Freezer 9. Heater

10. Euro 11.Inlet

12. Demister filter 13. Bolted connection
100. Auxiliary suction pump with filter of SF ₆ gas recovery system

110. Settlement 111. Space

112. First female thread 113. Entrance
114. Communication hole 120. Connection part
121. 1st external thread 122. 2nd external thread
123. Round Jaw 130. Bolts
131.Nut 140.Support
150. Cover 151. Third female screw
160. Check valve 170. Oil removal filter
171. Insertion hole 180. Support member
190. Bolts

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Claims (1)

A storage tank 2 in which SF ₆ gas, which is an insulating medium gas filled in the gas insulated switch (GIS: 1), is recovered and stored, and vacuum and injection of the gas insulated switch (1) and the storage tank (2) are performed. The vacuum pump (3) provided for the purpose, a semi-sealed compressor (4) for differentially recovering SF ₆ gas in the gas insulated switch (1) to the storage tank (2), and the semi-sealed compressor (4) The gas insulated switchgear assists the filter unit 5 including a dry filter for removing oil, dust and water remaining in the SF ₆ gas, a gas filter, an oil filter and a dust removing filter, and the semi-sealed compressor 4. 1 in the SF and ₆ secondary suction pump (6) for recovering the gas, and the oil removing filter (7) for removing the oil remaining in the recovered SF ₆ gas by the secondary suction pump 6, the storage tank A freezing section (8) for liquefying the SF ₆ gas recovered in (2); and the freezing section A heating unit 9 for vaporizing the SF ₆ liquefied through 8, a flow path 10 having one or more valves and connecting the respective components, the semi-sealed compressor 4, and an auxiliary suction pump ( 6), the remaining SF ₆ gas in the gas insulated switch 1 while controlling the output of the vacuum pump 3, the freezing section 8, the heating section 9 and controlling the temperature of the storage tank 2; In the SF ₆ gas recovery device comprising a control unit for determining the operating state of the automatic recovery and recharge for In the auxiliary suction pump (6), It has a space 111 in which the oil removal filter 170 is placed therein, the first female screw 112 is formed on one side, the other side having a settled portion having an inlet 113 into which the oil removal filter 170 is inserted. 110, It is settled in the space 111 of the settlement unit 110, one side is opened, the other side is formed with an insertion hole 171, the oil removal filter 170 for removing the oil remaining in the SF ₆ gas, One end of the first male screw 121 is fastened to the first female screw 112 is formed, the second female screw 122 is formed in the center of the other end, the center of the annular jaw 123 extending in the circumferential direction is formed And the connection portion 120, One end is fastened to the second female screw 122 of the connecting portion 120, the other end is introduced into the open side of the oil removal filter 170, the insertion hole 171 formed on the other side of the oil removal filter 170 And a bolt rod 130 that is secured to the oil removal filter 170 by being fastened by the nut 131, Support 140 for supporting the lower end of the other side of the oil removal filter 170 in order to prevent the other side of the oil removal filter 170 to be tilted downward or shaken by the operation of the device, A cover 150 coupled to the inlet 113 of the settling part 110 and having a third female screw 151 fastened to a pipe of the flow path 10 at a central portion thereof; The filter of the SF ₆ gas recovery device further comprises a check valve 160 formed in the inlet 11 through which the SF ₆ gas is introduced to prevent backflow of the SF ₆ gas introduced therein with oil. Integral auxiliary suction pump.

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