Mixed gas sampler and sampling method for mixed gas

Abstract

The present invention discloses a mixed gas sampler and a sampling method for a mixed gas. The mixed gas sampler includes a vacuum sampling container, a mixing diluter, a gas storage cylinder, a mixing pipeline and a sampling pipeline; the mixing diluter is provided with an inner cavity, and the inner cavity is provided with a first air inlet hole, a second air inlet hole and a mixing air hole communicated with the outside; the mixing air hole is communicated with the vacuum sampling container through the mixing pipeline, and a first electromagnetic valve is arranged between the mixing pipeline and the vacuum sampling container; the mixing pipeline is provided with a first exhaust pipe, and a second electromagnetic valve is arranged between the mixing pipeline and the first exhaust pipe, and the second electromagnetic valve is close to the first electromagnetic valve; the end of the first exhaust pipe is connected to the air inlet of a first vacuum pump. The present invention realizes gas mixing and gas dilution with a simple structure by means of the cooperation of each electromagnetic valve and the accurate collection of a gas flowmeter, and has simple operation and does not rely on manual operation.

Description

Technical Field

[0001] The present invention relates to the technical field of gas sampling, and particularly relates to a mixed gas sampler and a sampling method for mixed gas. Background Art

[0002] In the prior art, the concentration of polluted gas is usually detected by the dilution extraction method. First, the sample is taken through a dilution mixing device, and finally, the detection is carried out. Since the existing gas dilution mixing device automatically mixes and prepares precisely by passing high-concentration gas through a mass flow controller under computer control. However, the gas dilution mixing device has a complex structure, high equipment cost, and higher professional requirements for operators. Summary of the Invention

[0003] Aiming at the defects in the prior art, the present invention provides a mixed gas sampler, which includes a vacuum sampling container, a mixing and diluting device, a gas storage cylinder, a mixing pipeline, and a sampling pipeline;

[0004] The mixing and diluting device is provided with an inner cavity, and the inner cavity is provided with a first air inlet hole, a second air inlet hole, and a mixing air hole communicating with the outside;

[0005] The mixing air hole is communicated with the vacuum sampling container through the mixing pipeline, and a first electromagnetic valve is arranged between the mixing pipeline and the vacuum sampling container; the mixing pipeline is provided with a first exhaust pipe, and a second electromagnetic valve is arranged between the mixing pipeline and the first exhaust pipe, and the second electromagnetic valve is close to the first electromagnetic valve; the end of the first exhaust pipe is connected to the air inlet of a first vacuum pump;

[0006] The first air inlet hole is provided with a third electromagnetic valve and a first gas flowmeter, and the end of the first air inlet hole is communicated with a dilution gas bottle;

[0007] The second air inlet hole is communicated with the sampling pipeline, the sampling pipeline is communicated with and connected to a plurality of gas storage cylinders, and a fourth electromagnetic valve is respectively arranged between the air outlet of each gas storage cylinder and the sampling pipeline. An air inlet pipe communicating with the outside is arranged between each fourth electromagnetic valve and the air outlet of the corresponding gas storage cylinder;

[0008] The mixing and dilution device is provided with a chute that intersects perpendicularly with the second air inlet hole. One end of the chute is exposed, and a slidable valve body is arranged in the chute. The valve body is provided with a ventilation section, an air-blocking section, and an exhaust section. The ventilation section is provided with a through hole parallel to the second air inlet hole. One end of the valve body extends out of the chute. An expansion motor is arranged outside the mixing and dilution device, and the expansion shaft of the expansion motor is fixedly connected to the part of the valve body extending out of the chute. The valve body is driven to slide in the chute by the expansion motor. An exhaust hole is arranged inside the valve body, and an opening communicating with one end of the exhaust hole is arranged on one side surface of the valve body facing the sampling pipeline. The air-blocking section is located between the opening and the through hole. The other end of the exhaust hole is connected to a second exhaust pipe. The end of the second exhaust pipe is connected to the air inlet of a second vacuum pump.

[0009] The second air inlet hole is provided with a second gas flowmeter, and the second gas flowmeter is located between the inner cavity of the mixing and dilution device and the valve body.

[0010] The beneficial effects of this equipment are as follows: The ventilation section, air-blocking section, and exhaust section of the valve body realize the triple functions of inflating, closing, and removing residual gas. With the cooperation of each solenoid valve and the accurate collection of the gas flowmeter, gas mixing and gas dilution are realized with a simple structure, the operation is simple, and it does not rely on manual operation.

[0011] Preferably, the exhaust port of the first vacuum pump is connected to a first recovery bottle, and the exhaust port of the second vacuum pump is connected to a second recovery bottle.

[0012] Preferably, the number of gas storage bottles is 3 - 8.

[0013] Preferably, a deformable plastic pipe is arranged in the middle of the mixing pipeline.

[0014] The present invention also provides a sampling method for a single mixed gas, which is used for the above-mentioned mixed gas sampler. The mixing pipeline and the vacuum sampling container are both in negative pressure, and all solenoid valves are closed. The number of gas storage bottles is 1, and it includes the following steps:

[0015] S1. The expansion motor drives the valve body to align the ventilation section with the second air inlet hole. The fourth solenoid valve is opened, and the gas to be measured in the gas storage bottle is sucked into the mixing pipeline. When the value of the second gas flowmeter reaches the set value, the expansion motor drives the valve body to align the air-blocking section with the second air inlet hole, and the second air inlet hole is closed.

[0016] S2. The third solenoid valve is opened, and the dilution gas is sucked into the mixing pipeline. When the value of the first gas flowmeter reaches the set value, the third solenoid valve is closed.

[0017] S3. The first solenoid valve is opened. The plastic pipe is compressed, and the vacuum sampling container sucks the diluted gas to be measured in the mixing pipeline. The third solenoid valve is closed, and the sampling is completed.

[0018] The beneficial effects of this method are as follows: accurately suck a quantitative amount of the gas to be measured and the dilution gas, with a high accuracy of dilution ratio, which is conducive to improving the accuracy of measuring parameters such as the concentration and content of the gas to be measured in the later stage.

[0019] The present invention also provides a sampling method for a variety of mixed gases, which is used for the above-mentioned mixed gas sampler. The mixing pipeline and the vacuum sampling container are both under negative pressure, all solenoid valves are closed, and the number of gas storage cylinders is 3, namely gas storage cylinder A, gas storage cylinder B, and gas storage cylinder C, and it includes the following steps:

[0020] S1. The telescopic motor drives the valve body to align the ventilation section with the second air inlet hole, the fourth solenoid valve of gas storage cylinder A is opened, and the gas to be measured in gas storage cylinder A is sucked into the mixing pipeline. When the value of the second gas flowmeter reaches the set value, the fourth solenoid valve of gas storage cylinder A is closed, the telescopic motor drives the valve body to align the exhaust section with the second air inlet hole, and the second vacuum pump works to extract the residual gas in the sampling pipeline;

[0021] S2. The telescopic motor drives the valve body to align the ventilation section with the second air inlet hole, the fourth solenoid valve of gas storage cylinder B is opened, and the gas to be measured in gas storage cylinder B is sucked into the mixing pipeline. When the value of the second gas flowmeter reaches the set value, the fourth solenoid valve of gas storage cylinder B is closed, the telescopic motor drives the valve body to align the exhaust section with the second air inlet hole, and the second vacuum pump works to extract the residual gas in the sampling pipeline;

[0022] S3. The telescopic motor drives the valve body to align the ventilation section with the second air inlet hole, the fourth solenoid valve of gas storage cylinder C is opened, and the gas to be measured in gas storage cylinder C is sucked into the mixing pipeline. When the value of the second gas flowmeter reaches the set value, the fourth solenoid valve of gas storage cylinder C is closed, and the telescopic motor drives the valve body to align the airtight section with the second air inlet hole;

[0023] S4. The third solenoid valve is opened, and the dilution gas is sucked into the mixing pipeline. When the value of the first gas flowmeter reaches the set value, the third solenoid valve is closed;

[0024] S5. The first solenoid valve is opened, the plastic pipe is compressed, and the vacuum sampling container sucks the diluted gas to be measured in the mixing pipeline. The third solenoid valve is closed, and the sampling is completed.

[0025] After the sampling is completed, the telescopic motor drives the valve body to align the exhaust section with the second air inlet hole, and the second vacuum pump works to pump the residual gas in the sampling pipeline into the second recovery bottle for centralized treatment. After the sampling is completed, the second solenoid valve and the third solenoid valve are both opened, and the second vacuum pump works to pump the residual gas in the mixing pipeline into the first recovery bottle for centralized treatment.

[0026] The beneficial effects of this method are as follows: After each sampling of the gas to be measured with the sampling pipeline, the residual gas is cleared, resulting in minimal mutual influence between different gases to be measured. At the same time, the switching of the sampling pipeline can quickly suck different gases to be measured, accelerating the sampling speed and improving the sampling efficiency. Similarly, accurately measuring the gas volume through the gas flowmeter is beneficial to improving the accuracy of measuring parameters such as the concentration and content of the gas to be measured in the later stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0028] Figure 1 It is a schematic structural diagram of Embodiment 1;

[0029] Figure 2 is Figure 1 an enlarged view of part A in

[0030] In the drawings, vacuum sampling container 1, mixing and diluting device 2, gas storage cylinder 3, mixing pipeline 4, sampling pipeline 5, plastic pipe 6, first air inlet hole 7, second air inlet hole 8, mixing air hole 9, first solenoid valve 10, first exhaust pipe 11, second solenoid valve 12, first vacuum pump 13, first recovery bottle 14, third solenoid valve 15, first gas flowmeter 16, diluting gas bottle 17, fourth solenoid valve 18, inlet pipe 19, chute 20, valve body 21, ventilation section 22,, airtight section 23, exhaust section 24, telescopic motor 25, exhaust hole 26, second exhaust pipe 27, second vacuum pump 28, second recovery bottle 29, second gas flowmeter 30. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] The following will describe in detail the embodiments of the technical solutions of the present invention with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, so they are only examples and cannot be used to limit the protection scope of the present invention.

[0032] It should be noted that unless otherwise specified, the technical terms or scientific terms used in this application should have the ordinary meaning understood by those skilled in the art to which the present invention belongs.

[0033] Embodiment 1:

[0034] As Figure 1 、 Figure 2As shown in the figure, this embodiment provides a mixed gas sampler, which includes a vacuum sampling container 1, a mixing diluter 2, a gas storage cylinder 3, a mixing pipeline 4, and a sampling pipeline 5. A deformable plastic pipe 6 is provided in the middle of the mixing pipeline 4, and gas is discharged through the deflation of the plastic pipe 6 or inhaled through the inflation of the plastic pipe 6.

[0035] The mixing diluter 2 is provided with an inner cavity, and the inner cavity is provided with a first air inlet hole 7, a second air inlet hole 8, and a mixing air hole 9 communicating with the outside; the mixing air hole 9 is communicated with the vacuum sampling container 1 through the mixing pipeline 4, and a first electromagnetic valve 10 is provided between the mixing pipeline 4 and the vacuum sampling container 1; the mixing pipeline 4 is provided with a first exhaust pipe 11, and a second electromagnetic valve 12 is provided between the mixing pipeline 4 and the first exhaust pipe 11, and the second electromagnetic valve 12 is close to the first electromagnetic valve 10; the end of the first exhaust pipe 11 is connected to the air inlet of a first vacuum pump 13. The exhaust port of the first vacuum pump 13 is connected to a first recovery bottle 14. The first recovery bottle 14 prevents gas from leaking into the surrounding environment and eliminates potential hazards.

[0036] The first air inlet hole 7 is provided with a third electromagnetic valve 15 and a first gas flowmeter 16, and the end of the first air inlet hole 7 is communicated with a dilution gas bottle 17. The dilution gas in the dilution gas bottle 17 is selected according to the corresponding measured gas. The second air inlet hole 8 is communicated with the sampling pipeline 5, and the sampling pipeline 5 is communicated with no more than eight gas storage cylinders 3, and a fourth electromagnetic valve 18 is respectively provided between the air outlet of each gas storage cylinder 3 and the sampling pipeline 5, and an air inlet pipe 19 communicating with the outside is provided between each fourth electromagnetic valve 18 and the air outlet of the corresponding gas storage cylinder 3. There can also be only one gas storage cylinder 3 for the measurement of a single mixed gas.

[0037] The mixing diluter 2 is provided with a chute 20 perpendicular to the second air inlet hole 8. One end of the chute 20 is exposed, and a slidable valve body 21 is provided in the chute 20; the valve body 21 is provided with a ventilation section 22, an airtight section 23, and an exhaust section 24, and the ventilation section 22 is provided with a through hole parallel to the second air inlet hole 8; one end of the valve body 21 extends out of the chute 20, and a telescopic motor 25 is provided outside the mixing diluter 2. The telescopic shaft of the telescopic motor 25 is fixedly connected to the part of the valve body 21 extending out of the chute 20, and the valve body 21 is driven to slide in the chute 20 by the telescopic motor 25; an exhaust hole 26 is provided inside the valve body 21, and an opening communicating with one end of the exhaust hole 26 is provided on one side of the valve body 21 facing the sampling pipeline 5, and the airtight section 23 is located between the opening and the through hole; the other end of the exhaust hole 26 is connected to a second exhaust pipe 27; the end of the second exhaust pipe 27 is connected to the air inlet of a second vacuum pump 28. The exhaust port of the second vacuum pump 28 is connected to a second recovery bottle 29. The second air inlet hole 8 is provided with a second gas flowmeter 30, and the second gas flowmeter 30 is located between the inner cavity of the mixing diluter 2 and the valve body 21.

[0038] Example Two:

[0039] Example Two provides a sampling method for a single mixed gas, which is used for the mixed gas sampler in Example One. The mixing pipeline and the vacuum sampling container are both under negative pressure, all solenoid valves are closed, and the number of gas storage cylinders is 1. The method includes the following steps: S1. The telescopic motor drives the valve body to align the ventilation section with the second air inlet hole, the fourth solenoid valve is opened, and the gas to be measured in the gas storage cylinder is sucked into the mixing pipeline. When the value of the second gas flowmeter reaches the set value, the telescopic motor drives the valve body to align the airtight section with the second air inlet hole, and the second air inlet hole is closed; S2. The third solenoid valve is opened, and the dilution gas is sucked into the mixing pipeline. When the value of the first gas flowmeter reaches the set value, the third solenoid valve is closed; S3. The first solenoid valve is opened, the plastic pipe is compressed, and the vacuum sampling container sucks the diluted gas to be measured in the mixing pipeline. The third solenoid valve is closed, and the sampling is completed.

[0040] The beneficial effects of this method are as follows: accurately sucking a quantitative amount of the gas to be measured and the dilution gas, with a high accuracy of dilution ratio, which is beneficial to improving the accuracy of measuring parameters such as the concentration and content of the gas to be measured in the later stage.

[0041] Example Three:

[0042] Example Three provides a sampling method for multiple mixed gases, which is used for the mixed gas sampler in Example One. The mixing pipeline and the vacuum sampling container are both under negative pressure, all solenoid valves are closed, and the number of gas storage cylinders is 3, namely A gas storage cylinder, B gas storage cylinder and C gas storage cylinder. The method includes the following steps:

[0043] S1. The telescopic motor drives the valve body to align the ventilation section with the second air inlet hole. The fourth solenoid valve of the A gas storage cylinder is opened, and the gas to be measured in the A gas storage cylinder is sucked into the mixing pipeline. When the value of the second gas flowmeter reaches the set value, the fourth solenoid valve of the A gas storage cylinder is closed. The telescopic motor drives the valve body to align the exhaust section with the second air inlet hole, and the second vacuum pump operates to extract the residual gas in the sampling pipeline; S2. The telescopic motor drives the valve body to align the ventilation section with the second air inlet hole. The fourth solenoid valve of the B gas storage cylinder is opened, and the gas to be measured in the B gas storage cylinder is sucked into the mixing pipeline. When the value of the second gas flowmeter reaches the set value, the fourth solenoid valve of the B gas storage cylinder is closed. The telescopic motor drives the valve body to align the exhaust section with the second air inlet hole, and the second vacuum pump operates to extract the residual gas in the sampling pipeline; S3. The telescopic motor drives the valve body to align the ventilation section with the second air inlet hole. The fourth solenoid valve of the C gas storage cylinder is opened, and the gas to be measured in the C gas storage cylinder is sucked into the mixing pipeline. When the value of the second gas flowmeter reaches the set value, the fourth solenoid valve of the C gas storage cylinder is closed. The telescopic motor drives the valve body to align the airtight section with the second air inlet hole; S4. The third solenoid valve is opened, and the dilution gas is sucked into the mixing pipeline. When the value of the first gas flowmeter reaches the set value, the third solenoid valve is closed; S5. The first solenoid valve is opened, and the plastic tube is compressed. The vacuum sampling container sucks the diluted gas to be measured in the mixing pipeline. The third solenoid valve is closed, and the sampling is completed. After the sampling is completed, the telescopic motor drives the valve body to align the exhaust section with the second air inlet hole, and the second vacuum pump operates to pump the residual gas in the sampling pipeline into the second recovery bottle for centralized treatment. After the sampling is completed, both the second solenoid valve and the third solenoid valve are opened, and the second vacuum pump operates to pump the residual gas in the mixing pipeline into the first recovery bottle for centralized treatment.

[0044] The beneficial effects of this method are as follows: After each time the sampling pipeline sucks the gas to be measured, the residual gas is removed, so that the mutual influence between different gases to be measured is extremely small. At the same time, the switching of the sampling pipeline can quickly suck different gases to be measured, accelerating the sampling speed and improving the sampling efficiency. Similarly, accurately measuring the gas volume through the gas flowmeter is beneficial to improving the accuracy of measuring parameters such as the concentration and content of the gas to be measured in the later stage.

[0045] Finally, it should be noted that: The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: They can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; And these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered by the scope of the claims and the description of the present invention.

Claims

1. A mixed gas sampler; characterized in that: It includes a vacuum sampling container, a mixing and diluting device, a gas storage cylinder, a mixing pipeline and a sampling pipeline; The mixing and diluting device is provided with an inner cavity, and the inner cavity is provided with a first air inlet hole, a second air inlet hole and a mixing air hole communicating with the outside; The mixing air hole is communicated with the vacuum sampling container through the mixing pipeline, and a first electromagnetic valve is arranged between the mixing pipeline and the vacuum sampling container; the mixing pipeline is provided with a first exhaust pipe, and a second electromagnetic valve is arranged between the mixing pipeline and the first exhaust pipe, and the second electromagnetic valve is close to the first electromagnetic valve; the end of the first exhaust pipe is connected to the air inlet of a first vacuum pump; The first air inlet hole is provided with a third electromagnetic valve and a first gas flowmeter, and the end of the first air inlet hole is communicated with a dilution gas bottle; The second air inlet hole is communicated with the sampling pipeline, the sampling pipeline is communicated with a plurality of gas storage cylinders, and a fourth electromagnetic valve is respectively arranged between the air outlet of each gas storage cylinder and the sampling pipeline, and an air inlet pipe communicating with the outside is arranged between each fourth electromagnetic valve and the air outlet of the corresponding gas storage cylinder; The mixing and diluting device is provided with a chute perpendicular to the second air inlet hole, one end of the chute is exposed, and a slidable valve body is arranged in the chute; the valve body is provided with a ventilation section, an air blocking section and an exhaust section, and the ventilation section is provided with a through hole parallel to the second air inlet hole; one end of the valve body extends out of the chute, and a telescopic motor is arranged outside the mixing and diluting device, and the telescopic shaft of the telescopic motor is fixedly connected to the part of the valve body extending out of the chute, and the valve body is driven to slide in the chute by the telescopic motor; an exhaust hole is arranged inside the valve body, and an opening communicating with one end of the exhaust hole is arranged on one side surface of the valve body facing the sampling pipeline, and the air blocking section is located between the opening and the through hole; the other end of the exhaust hole is connected with a second exhaust pipe; the end of the second exhaust pipe is connected to the air inlet of a second vacuum pump; The second air inlet hole is provided with a second gas flowmeter, and the second gas flowmeter is located between the inner cavity of the mixing and diluting device and the valve body.

2. The mixed gas sampler according to claim 1, characterized in that: The exhaust port of the first vacuum pump is connected to a first recovery bottle.

3. The mixed gas sampler according to claim 2, characterized in that: The exhaust port of the second vacuum pump is connected to a second recovery bottle.

4. The mixed gas sampler according to claim 3, characterized in that: The number of the gas storage cylinders is 3 - 8.

5. The mixed gas sampler according to claim 4, characterized in that: A deformable plastic pipe is arranged in the middle of the mixing pipeline.

6. A sampling method for a single mixed gas, characterized in that: Applied to the mixed gas sampler according to claim 5, both the mixing pipeline and the vacuum sampling container are in negative pressure, all electromagnetic valves are closed, and the number of gas storage cylinders is 1, including the following steps: S1. The telescopic motor drives the valve body to align the ventilation section with the second air inlet hole, the fourth electromagnetic valve is opened, the gas to be measured in the gas storage cylinder is sucked into the mixing pipeline, and when the value of the second gas flowmeter reaches the set value, the telescopic motor drives the valve body to align the air blocking section with the second air inlet hole, and the second air inlet hole is closed; S2. The third electromagnetic valve is opened, the dilution gas is sucked into the mixing pipeline, and when the value of the first gas flowmeter reaches the set value, the third electromagnetic valve is closed; S3. The first electromagnetic valve is opened, the plastic pipe is compressed, and the vacuum sampling container sucks the diluted gas to be measured in the mixing pipeline, and the third electromagnetic valve is closed, and the sampling is completed.

7. A sampling method for a variety of mixed gases, characterized in that: Applied to the mixed gas sampler described in claim 5, both the mixing pipeline and the vacuum sampling container are under negative pressure, all solenoid valves are closed, and the number of gas storage cylinders is 3, namely gas storage cylinder A, gas storage cylinder B, and gas storage cylinder C, including the following steps: S1. The telescopic motor drives the valve body to align the ventilation section with the second air inlet hole, the fourth solenoid valve of gas storage cylinder A is opened, and the gas to be measured in gas storage cylinder A is sucked into the mixing pipeline. When the value of the second gas flowmeter reaches the set value, the fourth solenoid valve of gas storage cylinder A is closed, the telescopic motor drives the valve body to align the exhaust section with the second air inlet hole, and the second vacuum pump works to extract the residual gas in the sampling pipeline; S2. The telescopic motor drives the valve body to align the ventilation section with the second air inlet hole, the fourth solenoid valve of gas storage cylinder B is opened, and the gas to be measured in gas storage cylinder B is sucked into the mixing pipeline. When the value of the second gas flowmeter reaches the set value, the fourth solenoid valve of gas storage cylinder B is closed, the telescopic motor drives the valve body to align the exhaust section with the second air inlet hole, and the second vacuum pump works to extract the residual gas in the sampling pipeline; S3. The telescopic motor drives the valve body to align the ventilation section with the second air inlet hole, the fourth solenoid valve of gas storage cylinder C is opened, and the gas to be measured in gas storage cylinder C is sucked into the mixing pipeline. When the value of the second gas flowmeter reaches the set value, the fourth solenoid valve of gas storage cylinder C is closed, and the telescopic motor drives the valve body to align the airtight section with the second air inlet hole; S4. The third solenoid valve is opened, and the dilution gas is sucked into the mixing pipeline. When the value of the first gas flowmeter reaches the set value, the third solenoid valve is closed; S5. The first solenoid valve is opened, the plastic pipe is compressed, and the vacuum sampling container sucks the diluted gas to be measured in the mixing pipeline. The third solenoid valve is closed, and the sampling is completed.

8. The sampling method for a variety of mixed gases according to claim 7, characterized in that: After the sampling is completed, the telescopic motor drives the valve body to align the exhaust section with the second air inlet hole, and the second vacuum pump works to pump the residual gas in the sampling pipeline into the second recovery bottle for centralized treatment.

9. The sampling method for a variety of mixed gases according to claim 7, characterized in that: After the sampling is completed, both the second solenoid valve and the third solenoid valve are opened, and the second vacuum pump works to pump the residual gas in the mixing pipeline into the first recovery bottle for centralized treatment.

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