CN203971684U - A kind of sulfur hexafluoride and carbon tetrafluoride mist pre-separate device - Google Patents

Abstract

A pre-separation device for mixed gas of sulfur hexafluoride and carbon tetrafluoride relates to a pre-separation device for mixed gas. The purpose of the utility model is to solve the problem that the existing recycled sulfur hexafluoride and carbon tetrafluoride mixed gas has good compatibility and cannot be separated and purified. The device includes a mixed gas inlet pipe, a dryer, a filter, a compressor, an air cooler, a gas separation tower, the first heat exchanger of the -40°C refrigeration unit, the second heat exchanger of the -40°C refrigeration unit, the first Liquid level gauge, second liquid level gauge, weighing sensor, temperature sensor, liquid filling machine, sulfur hexafluoride gas outlet pipe, carbon tetrafluoride filling compressor and carbon tetrafluoride gas outlet pipe. The utility model can obtain a pre-separation device for mixed gas of sulfur hexafluoride and carbon tetrafluoride.

Description

A pre-separation device for mixed gas of sulfur hexafluoride and carbon tetrafluoride

technical field

The utility model relates to a mixed gas pre-separation device.

Background technique

SF ₆ gas is an important insulating medium, and is widely used in high-voltage electrical equipment for its excellent insulating properties and arc-extinguishing properties. But in practical application, SF ₆ gas also has some shortcomings in application. SF ₆ gas is a high greenhouse effect gas, its greenhouse effect index is 23900 times that of C0 ₂ , and it is listed as one of the six restricted greenhouse gases by the "Kyoto Protocol". SF ₆ is a heavy gas with a large molecular weight, and its liquefaction temperature is higher than that of ordinary gases. It is easy to liquefy in an environment with high pressure and low temperature, so it is not suitable for alpine regions. In addition, SF ₆ gas is expensive and is not suitable for electrical equipment with large gas consumption. Therefore, the industry began to use SF ₆ and CF ₄ mixed gas with low greenhouse effect to replace the single SF ₆ gas as the insulating medium, so as to effectively overcome the shortage of SF ₆ gas.

In the mixed gas, SF ₆ accounts for 40% to 50% (volume ratio), and CF ₄ accounts for 50% to 60% (volume ratio), so more than 50% of SF ₆ gas consumption can be saved. However, for high-voltage electrical equipment that uses mixed gas of SF ₆ and CF ₄ as insulation and arc extinguishing medium, there are still problems of recovery and treatment of mixed gas during equipment maintenance, troubleshooting and decommissioning, and CF ₄ is a low-toxic substance and cannot be discharged arbitrarily , so the recovered SF ₆ and CF ₄ mixed gas needs to be separated and purified to realize the recycling of SF ₆ and CF ₄ gas.

However, since both SF ₆ and CF ₄ are fluorides, the two gases have good compatibility, so for the mixed gas of SF ₆ and CF ₄ whose volume ratio is close to 1:1, it is difficult to completely separate the two gases, so it is necessary to Design a set of pre-separation device to conduct preliminary separation of the two gases.

Utility model content

The purpose of this utility model is to solve the problem that the mixed gas of sulfur hexafluoride and carbon tetrafluoride after recovery has good compatibility and cannot be separated and purified, and provides a kind of sulfur hexafluoride and tetrafluoride Carbon dioxide mixed gas pre-separation device.

A pre-separation device for sulfur hexafluoride and carbon tetrafluoride mixed gas, which includes a mixed gas inlet pipe, a drier, a filter, a compressor, an air cooler, a first gas separation tower, a second gas separation tower, - The first heat exchanger of 40℃ refrigeration unit, the second heat exchanger of -40℃ refrigeration unit, the first liquid level gauge, the second liquid level gauge, weighing sensor, temperature sensor, liquid filling machine, hexafluoride Sulfur gas outlet pipe, carbon tetrafluoride filling compressor and carbon tetrafluoride gas outlet pipe;

The mixed gas inlet pipe is connected to the inlet port of the manual ball valve _C1 , the outlet port of the manual ball valve _C1 is connected to the inlet port of the solenoid valve _V1 , and a first valve is provided between the manual ball valve _C1 and the solenoid valve _V1 Pressure gauge, the outlet port of the solenoid valve _V1 is connected to one end of the regulator valve _F1 , the other end of the regulator valve _F1 is connected to the inlet port of the dryer, and the outlet port of the dryer is connected to one end of the filter , there is a first pressure sensor between the dryer and the filter, the other end of the filter is connected to one end of the manual ball valve _C2 , the other end of the manual ball valve _C2 is connected to the inlet end of the compressor, and the outlet of the compressor The end of the air cooler is connected with one end of the air cooler, the other end of the air cooler is connected with the inlet port of the one-way valve _S1 , the outlet port of the one-way valve _S1 is connected with the inlet port of the solenoid valve _V2 , and the one-way valve A first pressure control switch is provided between _S1 and solenoid valve _V2 , and the outlet port of solenoid valve _V2 is connected to the inlet port of manual ball valve _C3 ;

Between the lower end of the first gas separation tower and the upper end of the second gas separation tower, there are stainless steel pipes which communicate with the first gas separation tower and the second gas separation tower respectively, and electric ball valves DF are arranged on the stainless steel pipes. ₁ ; the outlet port of the manual ball valve _C3 is connected with the bottom end of the first gas separation tower and an end of the electric ball valve DF ₁ respectively; one end of the manual ball valve C ₁₀ is respectively connected with the bottom end of the first gas separation tower and the electric ball valve DF ₁ The other end of the manual ball valve C ₁₀ is respectively connected with the upper end of the second gas separation tower and the other end of the electric ball valve DF ₁ ; the first heat exchanger of the -40°C refrigeration unit is installed in the first gas separation tower , the second gas separation tower is equipped with the second heat exchanger of the -40°C refrigeration unit, the first heat exchanger of the -40°C refrigeration unit is equipped with a refrigerant inlet valve D ₁ , and the second heat exchanger of the -40°C refrigeration unit A refrigerant inlet valve D ₂ is provided on the heat exchanger;

The upper end of the first gas separation tower is connected to one end of the manual ball valve _C7 , the other end of the manual ball valve _C7 is connected to the inlet port of the solenoid valve _V4 , and the outlet port of the solenoid valve _V4 is connected to the regulator valve F ₂ is connected to the inlet port, the outlet port of the pressure stabilizing valve _F2 is connected to the inlet port of the carbon tetrafluoride filling compressor, and the outlet port of the carbon tetrafluoride filling compressor is connected to one end of the manual ball valve _C9 A second pressure control switch and a fourth pressure gauge are arranged between the carbon tetrafluoride filling compressor and the manual ball valve _C9 , and the other end of the manual ball valve _C9 is connected to one end of the carbon tetrafluoride gas outlet pipe;

The lower end of the second gas separation tower is connected to one end of the manual ball valve _C4 , the other end of the manual ball valve _C4 is connected to one end of the manual ball valve _C5 , and the other end of the manual ball valve _C5 is connected to the liquid filling machine. The inlet port is connected, the outlet port of the liquid filling machine is connected with the inlet port of the one-way valve _S2 , the outlet port of the one-way valve _S2 is connected with the inlet port of the solenoid valve _V3 , and the outlet port of the solenoid valve _V3 It is connected with the inlet port of manual ball valve _C6 , a third pressure gauge and a second safety valve are installed between solenoid valve _V3 and manual ball valve _C6 , and the outlet port of manual ball valve _C6 is connected with the sulfur hexafluoride gas outlet pipe Pass.

The advantages of the utility model: the utility model provides a pre-separation device for the mixed gas of SF ₆ and CF ₄ , which can separate the gas in the high-voltage electrical equipment in operation with the mixed gas of SF ₆ and CF ₄ as the insulation and arc extinguishing medium. Recovery and separation; the content of CF ₄ in the separated SF ₆ gas of the utility model is less than 1% (m/m), and can be directly reused in electrical equipment using a mixed gas of SF ₆ and CF ₄ as a medium to reduce SF ₆ The emission of gas reaches the goal of environmental protection and energy saving; the utility model device has reasonable structure, high gas purification treatment efficiency, high safety, strong practicability, and has wider popularization value.

The utility model can obtain a pre-separation device for mixed gas of sulfur hexafluoride and carbon tetrafluoride.

Description of drawings

Fig. 1 is a schematic structural view of a pre-separation device for mixed gas of sulfur hexafluoride and carbon tetrafluoride described in the first embodiment.

Detailed ways

Specific embodiment one: in conjunction with Fig. 1, this embodiment is a kind of sulfur hexafluoride and carbon tetrafluoride mixed gas pre-separation device, it comprises mixed gas inlet pipe 1, drier 2, filter 3, compressor 4, Air cooler 5, first gas separation tower 6, second gas separation tower 7, first heat exchanger 9 of -40°C refrigeration unit 8, second heat exchanger 10 of -40°C refrigeration unit 8, first liquid Level gauge 11, second liquid level gauge 12, load cell 13, temperature sensor 14, liquid filling machine 15, sulfur hexafluoride gas outlet pipe 16, carbon tetrafluoride filling compressor 49 and carbon tetrafluoride gas outlet pipe 34;

The mixed gas inlet pipe 1 is connected to the inlet port of the manual ball valve C ₁ 17, the outlet port of the manual ball valve C ₁ 17 is connected to the inlet port of the solenoid valve V ₁ 19, and the manual ball valve C ₁ 17 is connected to the solenoid valve V ₁ 19 There is a first pressure gauge 18 between them, the outlet end of the solenoid valve V ₁ 19 is connected to one end of the pressure stabilizing valve F ₁ 20, the other end of the pressure stabilizing valve F ₁ 20 is connected to the inlet end of the dryer 2, and the drying The outlet end of the dryer 2 is connected with one end of the filter 3, the first pressure sensor 22 is arranged between the drier 2 and the filter 3, the other end of the filter 3 is connected with one end of the manual ball valve C ₂ 23, the manual ball valve The other end of C ₂ 23 is connected to the inlet port of compressor 4, the outlet port of compressor 4 is connected to one end of air cooler 5, and the other end of air cooler 5 is connected to the inlet port of check valve S ₁ 24 connection, the outlet port of the one-way valve S ₁ 24 is connected to the inlet port of the solenoid valve V ₂ 26, a first pressure control switch 25 is provided between the one-way valve S ₁ 24 and the solenoid valve V ₂ 26, and the solenoid valve V ₂ The outlet port of 26 is connected with the inlet port of manual ball valve C ₃ 27;

Between the lower end of the first gas separation tower 6 and the upper end of the second gas separation tower 7, there is a stainless steel pipe 28 which is communicated with the first gas separation tower 6 and the second gas separation tower 7 respectively. There is an electric ball valve DF ₁ 29 on it; the outlet end of the manual ball valve C ₃ 27 is respectively connected with the bottom end of the first gas separation tower 6 and one end of the electric ball valve DF ₁ 29; one end of the manual ball valve C ₁₀ 48 is respectively connected with the first The bottom end of the gas separation tower 6 is connected to one end of the electric ball valve DF ₁ 29, and the other end of the manual ball valve C ₁₀ 48 is respectively connected to the upper end of the second gas separation tower 7 and the other end of the electric ball valve DF ₁ 29; the first gas The separation tower 6 is provided with the first heat exchanger 9 of the -40°C refrigeration unit 8, the second gas separation tower 7 is provided with the second heat exchanger 10 of the -40°C refrigeration unit 8, and the -40°C refrigeration unit 8 The first heat exchanger 9 is provided with a refrigerant inlet valve D ₁ 8-1, and the second heat exchanger 10 of the -40°C refrigeration unit 8 is provided with a refrigerant inlet valve D ₂ 8-2;

The upper end of the first gas separation tower 6 is connected to one end of the manual ball valve _C730 , the other end of the manual ball valve _C730 is connected to the inlet port of the solenoid valve _V431 , and the outlet port of the solenoid valve _V431 It is connected with the inlet port of the pressure stabilizing valve F ₂ 32, the outlet port of the pressure stabilizing valve F ₂ 32 is connected with the inlet port of the carbon tetrafluoride filling compressor 49, and the outlet port of the carbon tetrafluoride filling compressor 49 It communicates with one end of the manual ball valve C ₉ 33, a second pressure control switch 46 and a fourth pressure gauge 47 are provided between the carbon tetrafluoride filling compressor 49 and the manual ball valve C ₉ 33, and the other end of the manual ball valve C ₉ 33 One end is connected with an end of carbon tetrafluoride gas outlet pipe 34;

The lower end of the second gas separation tower 7 is connected to one end of the manual ball valve _C435 , the other end of the manual ball valve _C435 is connected to one end of the manual ball valve _C536 , and the other end of the manual ball valve _C536 is connected to The inlet port of the liquid filling machine 15 is connected, the outlet port of the liquid filling machine 15 is connected with the inlet port of the one-way valve _S237 , and the outlet port of the one-way valve _S237 is connected with the inlet port of the solenoid valve _V338 The outlet port of the solenoid valve _V338 is connected to the inlet port of the manual ball valve _C639 , and a third pressure gauge 40 and a second safety valve 41 are provided between the solenoid valve _V338 and the manual ball valve _C639 . The outlet end of the manual ball valve C ₆ 39 communicates with the sulfur hexafluoride gas outlet pipe 16 .

Fig. 1 is the structural schematic diagram of a kind of sulfur hexafluoride and carbon tetrafluoride mixed gas pre-separation device described in specific embodiment 1, in Fig. 1, 1 is a mixed gas inlet pipe, 2 is a drier, 3 is a filter, 4 is the compressor, 5 is the air cooler, 6 is the first gas separation tower, 7 is the second gas separation tower, 8 is the -40 ℃ refrigeration unit, 9 is the first heat exchanger, and 10 is the second heat exchanger , 11 is the first liquid level gauge, 12 is the second liquid level gauge, 13 is the load cell, 14 is the temperature sensor, 15 is the liquid filling machine, 16 is the sulfur hexafluoride gas outlet pipe, 17 is the manual ball valve C ₁ , 18 is the first pressure gauge, 19 is the solenoid valve V ₁ , 20 is the pressure stabilizing valve F ₁ , 21 is the electric heating rod, 22 is the first pressure sensor, 23 is the manual ball valve C ₂ , 24 is the one-way valve S ₁ , 25 is the first pressure control switch, 26 is the solenoid valve V ₂ , 27 is the manual ball valve C ₃ , 28 is the stainless steel pipe, 29 is the electric ball valve DF ₁ , 30 is the manual ball valve C ₇ , 31 is the solenoid valve V ₄ , 32 is pressure stabilizing valve F ₂ , 33 is manual ball valve C ₉ , 34 is carbon tetrafluoride gas outlet pipe, 35 is manual ball valve C ₄ , 36 is manual ball valve C ₅ , 37 is one-way valve S ₂ , 38 is electromagnetic Valve V ₃ , 39 is the manual ball valve C ₆ , 40 is the third pressure gauge, 41 is the second safety valve, 42 is the solenoid valve V ₆ , 43 is the vacuum pressure sensor, 44 is the solenoid valve V ₅ , 45 is the vacuum pump, 46 47 is the fourth pressure gauge, 48 is the manual ball valve C ₁₀ , 49 is the compressor filled with carbon tetrafluoride, 6-1 is the manual ball valve C ₈ , 6-2 is the first safety valve, 6-3 is the second pressure gauge, 6-4 is the second pressure sensor, 8-1 is the refrigerant inlet valve D ₁ , and 8-2 is the refrigerant inlet valve D ₂ ;

In this embodiment, the manual ball valve: used for the adjustment of the gas flow and the opening or closing of the gas flow path; the solenoid valve: used for opening or closing the gas flow path; the regulator valve: used for the pressure control of the gas; the one-way valve: For one-way control of gases.

Advantages of this embodiment: This embodiment provides a pre-separation device for mixed gas of SF ₆ and CF ₄ , which can separate the gas in high-voltage electrical equipment that uses the mixed gas of SF ₆ and CF ₄ as insulation and arc extinguishing medium. Recovery and separation; in the _separated SF in the present embodiment, the content of _CF is less than 1% (m/m), and it can be directly reused in the electrical equipment with SF _{and CF} as the medium, so as to reduce _SF The emission of gas reaches the goal of environmental protection and energy saving; the device structure of this embodiment is reasonable, the gas purification treatment efficiency is high, the safety is high, the practicability is strong, and it has a wider promotion value.

In this embodiment, a pre-separation device for mixed gas of sulfur hexafluoride and carbon tetrafluoride can be obtained.

Specific embodiment two: the difference between this embodiment and specific embodiment one is that: the first liquid level gauge 11 is provided outside the first gas separation tower 6, and the second pressure gauge 11 is provided at the upper end of the first gas separation tower 6 The sensor 6-4, and the upper end of the first gas separation tower 6 is connected with one end of the manual ball valve C ₈ 6-1, and the other end of the manual ball valve C ₈ 6-1 is connected with the second pressure gauge 6-3 and the first safety valve respectively. Valve 6-2 is connected. Others are the same as in the first embodiment.

The second pressure sensor 6-4 is used for monitoring the gas pressure in the first gas separation tower 6, and the first safety valve 6-2 is used for the emergency pressure relief when the gas overpressure in the first gas separation tower 6; the first liquid level The gauge 11 is used to observe the liquid level height of the liquid in the first gas separation tower 6 .

Specific embodiment three: the difference between this embodiment and one of specific embodiments one or two is that: the second liquid level gauge 12 is arranged outside the second gas separation tower 7, and the outer bottom of the second gas separation tower 7 A load cell 13 is provided at the end, and a temperature sensor 14 is provided at the lower part of the second gas separation tower 7 . Others are the same as in the first or second embodiment.

The temperature sensor 14 has a measuring range of -50°C to 100°C and an accuracy of ±0.5°C, and is used to monitor the gas temperature in the tower; the second liquid level gauge 12 is used to observe the liquid level in the second gas separation tower 7 .

Embodiment 4: The difference between this embodiment and one of Embodiments 1 to 3 is that the outlet port of the manual ball valve C ₁ 17 and the inlet port of the pressure stabilizing valve F ₂ 32 are connected to the solenoid valve V ₆ 42 respectively. One end is connected, the other end of the solenoid valve _V642 is connected with one end of the solenoid valve _V544 , a vacuum pressure sensor 43 is arranged between the solenoid valve _V642 and the solenoid valve _V544 , and the other end of the solenoid valve _V544 One end is connected with the vacuum pump 45, and the vacuum pump 45 is a two-stage rotary vane type. Others are the same as those in Embodiments 1 to 3.

The vacuum pump 45 is used to evacuate the steel cylinder and the system in the device.

Embodiment 5: The difference between this embodiment and Embodiment 1 to Embodiment 4 is that the dryer 2 is made of stainless steel, the wall thickness of the tank body is 6 mm, and the volume is 30 L. The dryer 2 has an electric heating rod 21 built in it. , The filter 3 is a mesh filter. Others are the same as the specific embodiments 1 to 4.

The dryer 2 is used to adsorb and remove the water vapor in the mixed gas; the dryer 2 has an electric heating rod 21 built in to heat the dryer 2, and the moisture in the adsorbent is drawn out by vacuuming, so that it can be regenerated and the adsorption drying can be resumed Ability; Filter 3 prevents broken desiccant particles from entering the subsequent system.

Embodiment 6: This embodiment differs from Embodiments 1 to 5 in that: the compressor 4 is an oil-free compressor; the compressor 49 filled with carbon tetrafluoride is an oil-free compressor. Others are the same as those in Embodiments 1 to 5.

Embodiment 7: The difference between this embodiment and Embodiments 1 to 6 is that the material of the air cooler 5 is aluminum alloy, and the form of the air cooler 5 is a combination of tubes and fins. is 60m ² ; the liquid filling machine 15 is a piston type. Others are the same as those in Embodiments 1 to 6.

The air cooler 5 forcibly takes away the heat in the outlet gas of the compressor.

Embodiment 8: The difference between this embodiment and one of Embodiments 1 to 7 is that: the first heat exchanger 9 is a serpentine tube exchanger made of stainless steel; the second heat exchanger 10 is made of stainless steel Serpentine tube exchanger. Others are the same as those in Embodiments 1 to 7.

The first heat exchanger 9 and the second heat exchanger 10 deeply lower the temperature of the gas, and promote the liquefaction (solidification) and separation of the gas.

Specific embodiment nine: the difference between this embodiment and one of the specific embodiments one to eight is that the first gas separation tower 6 adopts a multi-layer screen structure, the material is stainless steel, the wall thickness of the tank body is 6mm, and the volume is 120L; the material of the second gas separation tower 7 is stainless steel, the tank body wall thickness is 6mm, and the volume is 120L; the diameter of the stainless steel pipe 28 is 500mm, and the outer diameter is 512mm. Others are the same as those in Embodiments 1 to 8.

The first gas separation tower 6 adopts a multi-layer screen structure to increase the gas contact area and promote the combination and liquefaction of SF ₆ gas molecules, thereby separating it from CF ₄ .

Claims (9)

1. A sulfur hexafluoride and carbon tetrafluoride mixed gas pre-separation device is characterized in that it comprises a mixed gas inlet pipe (1), dryer (2), filter (3), compressor (4), The air cooler (5), the first gas separation tower (6), the second gas separation tower (7), the first heat exchanger (9) of the -40°C refrigeration unit (8), the -40°C refrigeration unit (8 ), the second heat exchanger (10), the first liquid level gauge (11), the second liquid level gauge (12), the load cell (13), the temperature sensor (14), the liquid filling machine (15), Sulfur hexafluoride gas outlet pipe (16), carbon tetrafluoride filling compressor (49) and carbon tetrafluoride gas outlet pipe (34); The mixed gas inlet pipe (1) is connected to the inlet port of the manual ball valve C ₁ (17), the outlet port of the manual ball valve C ₁ (17) is connected to the inlet port of the solenoid valve V ₁ (19), and the manual ball valve C A first pressure gauge (18) is provided between ₁ (17) and the solenoid valve V ₁ (19), and the outlet port of the solenoid valve V ₁ (19) is connected to one end of the pressure stabilizing valve F ₁ (20). The other end of the valve F ₁ (20) is connected to the inlet port of the drier (2), the outlet port of the drier (2) is connected to one end of the filter (3), and the drier (2) is connected to the filter (3) ) is provided with a first pressure sensor (22), the other end of the filter (3) is connected to one end of the manual ball valve C ₂ (23), and the other end of the manual ball valve C ₂ (23) is connected to the compressor (4) The inlet port of the compressor (4) is connected with one end of the air cooler (5), and the other end of the air cooler (5) is connected with the inlet port of the one-way valve S ₁ (24), The outlet port of the one-way valve S ₁ (24) is connected to the inlet port of the solenoid valve V ₂ (26), and a first pressure control switch is arranged between the one-way valve S ₁ (24) and the solenoid valve V ₂ (26). (25), the outlet end of the solenoid valve _V2 (26) is connected with the inlet end of the manual ball valve _C3 (27); Between the upper end of the lower end of described first gas separation tower (6) and the second gas separation tower (7), be provided with and communicate with the first gas separation tower (6) and the second gas separation tower (7) respectively The stainless steel pipe (28) is provided with an electric ball valve DF ₁ (29) on the stainless steel pipe (28); the outlet end of the manual ball valve C ₃ (27) is respectively connected to the bottom end of the first gas separation tower (6) and the electric ball valve DF ₁ (29) is connected at one end; one end of the manual ball valve C ₁₀ (48) is connected with the bottom end of the first gas separation tower (6) and one end of the electric ball valve DF ₁ (29) respectively, and the manual ball valve C ₁₀ (48 ) is connected with the upper end of the second gas separation tower (7) and the other end of the electric ball valve DF ₁ (29) respectively; the first gas separation tower (6) is equipped with the first A heat exchanger (9), the second heat exchanger (10) of the -40°C refrigeration unit (8) is provided in the second gas separation tower (7), and the first heat exchange of the -40°C refrigeration unit (8) Refrigerant inlet valve D ₁ (8-1) is provided on the device (9), and refrigerant inlet valve D ₂ (8-2) is provided on the second heat exchanger (10) of the -40°C refrigeration unit (8) ; The upper end of the first gas separation tower (6) is connected with one end of the manual ball valve C ₇ (30), and the other end of the manual ball valve C ₇ (30) is connected with the inlet end of the solenoid valve V ₄ (31), The outlet port of the electromagnetic valve V ₄ (31) is connected with the inlet port of the pressure stabilizing valve F ₂ (32), and the outlet port of the pressure stabilizing valve F ₂ (32) is connected with the inlet port of the carbon tetrafluoride filling compressor (49) The ends are connected, the outlet end of the carbon tetrafluoride filling compressor (49) is connected with one end of the manual ball valve C ₉ (33), the carbon tetrafluoride filling compressor (49) is connected with the manual ball valve C ₉ (33) A second pressure control switch (46) and a fourth pressure gauge (47) are arranged between, and the other end of the manual ball valve _C9 (33) is connected with an end of the tetrafluorocarbon gas outlet pipe (34); The lower end of the second gas separation tower (7) is connected to one end of the manual ball valve _C4 (35), and the other end of the manual ball valve _C4 (35) is connected to one end of the manual ball valve _C5 (36). The other end of the ball valve C ₅ (36) is connected to the inlet of the liquid filling machine (15), and the outlet of the liquid filling machine (15) is connected to the inlet of the one-way valve S ₂ (37). The outlet port of valve S ₂ (37) is connected to the inlet port of solenoid valve V ₃ (38), the outlet port of solenoid valve V ₃ (38) is connected to the inlet port of manual ball valve C ₆ (39), and the solenoid valve V ₃ (38) and the manual ball valve C ₆ (39) are provided with a third pressure gauge (40) and a second safety valve (41), the outlet end of the manual ball valve C ₆ (39) is connected to the sulfur hexafluoride gas outlet pipe (16) are connected. 2. A pre-separation device for sulfur hexafluoride and carbon tetrafluoride mixed gas according to claim 1, characterized in that a first liquid level gauge (11) is arranged outside the first gas separation tower (6) ), the upper end of the first gas separation tower (6) is provided with a second pressure sensor (6-4), and the upper end of the first gas separation tower (6) is connected with one end of the manual ball valve C ₈ (6-1), The other end of the manual ball valve C ₈ (6-1) is respectively connected with the second pressure gauge (6-3) and the first safety valve (6-2). 3. A pre-separation device for sulfur hexafluoride and carbon tetrafluoride mixed gas according to claim 2, characterized in that a second liquid level gauge (12) is arranged outside the second gas separation tower (7) ), the outer bottom of the second gas separation tower (7) is provided with a load cell (13), and the inner bottom of the second gas separation tower (7) is provided with a temperature sensor (14). 4. A pre-separation device for sulfur hexafluoride and carbon tetrafluoride mixed gas according to claim 3, characterized in that the outlet port of the manual ball valve C ₁ (17) and the pressure stabilizing valve F ₂ (32 ) inlet ports are respectively connected with one end of solenoid valve V ₆ (42), the other end of solenoid valve V ₆ (42) is connected with one end of solenoid valve V ₅ (44), solenoid valve V ₆ (42) and solenoid valve A vacuum pressure sensor (43) is arranged between the valves V ₅ (44), and the other end of the solenoid valve V ₅ (44) is connected with a vacuum pump (45), which is a two-stage rotary vane type. 5. A pre-separation device for sulfur hexafluoride and carbon tetrafluoride mixed gas according to claim 4, characterized in that the dryer (2) is made of stainless steel, the tank body has a wall thickness of 6mm and a volume of 30L , the drier (2) has a built-in electric heating rod (21), and the filter (3) is a mesh filter. 6. A kind of sulfur hexafluoride and carbon tetrafluoride mixed gas pre-separation device according to claim 5, it is characterized in that described compressor (4) is oil-free compressor; Machine (49) is an oil-free compressor. 7. A pre-separation device for sulfur hexafluoride and carbon tetrafluoride mixed gas according to claim 6, characterized in that the material of the air cooler (5) is aluminum alloy, and the air cooler (5) The form is the combination of tube and warp, and the heat dissipation area is 60m ² ; the liquid filling machine (15) is piston type. 8. A pre-separation device for sulfur hexafluoride and carbon tetrafluoride mixed gas according to claim 7, characterized in that the first heat exchanger (9) is a serpentine tube exchanger made of stainless steel; The second heat exchanger (10) is a serpentine tube exchanger made of stainless steel. 9. A pre-separation device for sulfur hexafluoride and carbon tetrafluoride mixed gas according to claim 8, characterized in that the first gas separation tower (6) adopts a multi-layer screen structure, and the material is Stainless steel, tank body wall thickness 6mm, volume is 120L; The material of the second gas separation tower (7) is stainless steel, tank body wall thickness 6mm, volume is 120L; The diameter of stainless steel pipe (28) is 500mm, and outer diameter is 512mm.