A goaf bundle pipe pneumatic negative pressure air extraction device and method

Abstract

The present invention discloses a gob goaf bundle tube pneumatic negative pressure air extraction device and method, which includes a Laval tube, an exhaust pipe and a gas storage pipe; a vacuum cavity is provided in the exhaust pipe, and the vacuum cavity is communicated with the underground high-pressure air pipeline through the Laval tube. The air flow in the underground high-pressure air pipeline enters the Laval tube and is accelerated by the Laval tube and then discharged into the vacuum cavity. At this time, the high-speed air flow will compress the gas in the vacuum cavity and discharge it from the exhaust port, generating negative pressure in the vacuum cavity, and further generating negative pressure in the gas storage pipe. At this time, the gas in the bundle tube connected to the gas storage pipe and at the position of the gob goaf where the port is located is affected by the negative pressure and is extracted into the gas storage pipe, effectively ensuring the extraction efficiency of the bundle tube. In addition, multiple bundle tubes distributed at different positions in the gob goaf are all connected to the gas storage pipe, and the opening sequence is controlled by each ball valve. Without moving this air extraction device and without external power supply, the gas at different positions in the gob goaf can be sampled.

Description

Technical Field

[0001] The present invention relates to a gas extraction device and method, and particularly to a gob goaf bundle tube pneumatic negative pressure air extraction device and method. Background Art

[0002] The method of collecting gas by embedding bundle tubes in the gob is a common technical means for analyzing the gas composition and distribution law in the gob, judging the degree of spontaneous oxidation of the residual coal in the gob, and delineating the "three zones" of coal spontaneous combustion in the gob.

[0003] The common method of extracting gas from the gob is the negative pressure air extraction method, that is, a negative pressure is generated at the orifice of the bundle tube by a gas negative pressure automatic air extraction pump or an explosion-proof vacuum pump, so that the pressure at the orifice of the bundle tube is lower than the internal pressure of the gob, thereby extracting the gas in the gob. Although both pumps can be used to extract gas from the gob, they both have disadvantages:

[0004] 1. The gas negative pressure automatic air extraction pump is suitable for short-distance bundle tube air extraction. When the bundle tube is long, the frictional resistance of the inner wall of the bundle tube to the gas increases, resulting in increased power consumption of the equipment and reduced air extraction efficiency.

[0005] 2. The explosion-proof vacuum pump is large in volume and weight. The test period of the "three zones" of coal spontaneous combustion in the gob is short, and the air extraction location needs to be frequently changed, which greatly increases the workload. In addition, the explosion-proof vacuum pump requires a dedicated power supply, and the bundle tube laying position is usually far from the power supply, and hundreds to thousands of meters of cables need to be erected separately. Moreover, the cables need to be recovered after gas extraction, which greatly increases the gas extraction cost and is also prone to electrical safety hazards.

[0006] Therefore, how to provide a new air extraction device and method that can not only ensure the air extraction efficiency of the bundle tube, but also has no mechanical moving parts and does not require an external power supply, so as to facilitate the air extraction device to extract different positions of the bundle tube, is one of the research directions in this industry. Summary of the Invention

[0007] In view of the problems existing in the above-mentioned prior art, the present invention provides a gob goaf bundle tube pneumatic negative pressure air extraction device and method, which can not only ensure the air extraction efficiency of the bundle tube, but also has no mechanical moving parts and does not require an external power supply, so as to facilitate the air extraction device to extract different positions of the bundle tube.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is: a gob goaf bundle tube pneumatic negative pressure air extraction device, including a Laval tube, an exhaust pipe and a gas storage pipe;

[0009] The exhaust pipe is provided with a vacuum cavity, and an air inlet and an air outlet are respectively provided at both ends of the exhaust pipe, and an air extraction port is provided at the side of the exhaust pipe;

[0010] The intake end of the Laval tube is connected to the underground high-pressure air pipeline through the pipeline adapter one; the outlet end of the Laval tube extends into the vacuum cavity from the air inlet, and the outer surface of the Laval tube is fixedly sealed with the air inlet; the Laval tube is used to accelerate the airflow in the underground high-pressure air pipeline and then discharge it into the vacuum cavity, and discharge it from the exhaust port, so as to generate negative pressure in the vacuum cavity.

[0011] One end of the gas storage pipe is connected to the vacuum cavity through the air extraction port, and the other end of the gas storage pipe is provided with a drain pipe, and a drain ball valve is installed on the drain pipe; the side of the gas storage pipe is equipped with a pipeline adapter two and a pipeline adapter three. The pipeline adapter two is close to one end of the gas storage pipe, and the pipeline adapter three is close to the other end of the gas storage pipe. The pipeline adapter three is used to connect the bundle pipes arranged in the goaf, so that the gas in the bundle pipes is pumped into the gas storage pipe; the pipeline adapter two is used to connect the gas negative pressure automatic gas sampler to collect the gas in the gas storage pipe; a ball valve one is installed at the connection between one end of the gas storage pipe and the air extraction port. When the ball valve one is opened, the gas storage pipe is connected to the vacuum cavity and is in a negative pressure state to pump the gas inside the bundle pipe. When it is closed, the gas storage pipe retains the pumped gas in the gas storage pipe and is collected by the gas negative pressure automatic gas sampler.

[0012] Further, a ball valve two is installed on the pipeline adapter one, a ball valve three is installed on the pipeline adapter two, and a ball valve four is installed on the pipeline adapter three. Each ball valve is used to control the on-off of the pipeline where it is located.

[0013] Further, a flow meter is installed on the gas storage pipe to monitor the gas flow rate flowing through the gas storage pipe.

[0014] Further, there are four pipeline adapters three in total. The four pipeline adapters three are evenly distributed on the outer surface of the gas storage pipe and are on the same horizontal plane. By setting multiple pipeline adapters three, multiple bundle pipes can be connected at the same time, and there is no need to disassemble and reinstall each bundle pipe after the gas sampling process is completed for the next bundle pipe.

[0015] Further, the flow meter is a pressure type flow meter. Using this structure not only has stable operation, but also is convenient to install.

[0016] Further, the outer surface of the Laval tube and the air inlet are fixedly sealed through threads and sealing rings. Using this connection method is not only convenient for installation, but also has a good sealing effect.

[0017] The working method of the above-mentioned goaf bundle tube pneumatic negative pressure air extraction device is specifically as follows:

[0018] ① Initially, all the ball valves of this device are in the closed state. Connect multiple bundle pipes arranged at different positions in the goaf to the gas storage pipe through each pipeline adapter three respectively, and connect the intake end of the Laval tube to the underground high-pressure air pipeline through the pipeline adapter one;

[0019] ②Before starting work, first open the drain ball valve and ball valve 1, connect a negative pressure pressure gauge to the drain pipe, and then slowly open ball valve 2. The airflow in the underground high-pressure air pipeline enters the Laval tube and is accelerated by the Laval tube and then discharged into the vacuum cavity. At this time, the high-speed airflow will compress the gas in the vacuum cavity and discharge it from the exhaust port, creating a negative pressure in the vacuum cavity, and then creating a negative pressure in the gas storage pipe. By observing the reading of the negative pressure pressure gauge until the reading no longer changes, it indicates that the negative pressure environment in the gas storage pipe is stable at this time. Then close the drain ball valve and remove the negative pressure pressure gauge;

[0020] ③First, select one of the multiple bundle tubes as the bundle tube that needs to collect gas, and slowly open ball valve 4 corresponding to this bundle tube to connect this bundle tube with the inside of the gas storage pipe. Since the inside of the gas storage pipe is in a negative pressure environment, the port of the bundle tube in the goaf continuously extracts the surrounding gas at this time. Adjust the opening degree of ball valve 4 according to the reading of the observed flowmeter to ensure that the gas collection speed will not cause too much disturbance to the original flow field in the goaf;

[0021] ④According to the length of the bundle tube selected in step ③ and the reading of the flowmeter, determine the gas collection time so that the gas in the goaf enters the gas storage pipe through this bundle tube, and the gas storage pipe is filled with the gas inside the goaf collected through this bundle tube;

[0022] ⑤During the entire gas extraction process, keep the gas storage pipe in a vertical state so that the water mixed in the extracted gas converges to the bottom of the gas storage pipe;

[0023] ⑥After reaching the gas collection time determined in step ④, close ball valve 1 so that the collected gas remains in the gas storage pipe;

[0024] ⑦Connect the gas negative pressure automatic gas pump to pipe joint 2, open ball valve 3, start the gas negative pressure automatic gas pump, and start collecting the gas in the gas storage pipe. At this time, ball valve 4 corresponding to this bundle tube remains open so that the gas in the bundle tube continues to supplement into the gas storage pipe;

[0025] ⑧After continuously extracting gas for a period of time, close the gas negative pressure automatic gas pump, ball valve 3, and ball valve 4 to complete the gas collection work. Then open ball valve 1 and the drain ball valve to drain the accumulated water at the bottom of the gas storage pipe through the drain pipe; thus completing the gas collection process of the current bundle tube;

[0026] ⑨Then select another bundle tube and repeat steps ③ to ⑧. After repeating this many times, the gas extraction can be carried out for each bundle tube respectively, realizing the gas collection process at different positions in the goaf.

[0027] Furthermore, a protective tube is provided outside the bundle tube. Adding a protective tube can provide a better protection effect for the bundle tube and ensure the smoothness of the internal channel of the bundle tube after being impacted externally.

[0028] Compared with the prior art, the present invention combines a Laval tube, an exhaust pipe and a gas storage pipe, and has the following advantages:

[0029] 1. A vacuum cavity is arranged in the exhaust pipe of the present invention. The vacuum cavity is communicated with the underground high-pressure air pipeline through a Laval tube. The airflow in the underground high-pressure air pipeline enters the Laval tube and is accelerated by the Laval tube and then discharged into the vacuum cavity. At this time, the high-speed airflow will compress the gas in the vacuum cavity and discharge it from the exhaust port, generating a negative pressure in the vacuum cavity, and further generating a negative pressure in the gas storage pipe. At this time, the gas in the bundle tube connected to the gas storage pipe and the goaf position where the port is located is affected by the negative pressure and is extracted into the gas storage pipe; because the negative pressure generated by this pneumatic method is relatively large, it can have a good gas extraction effect on relatively long bundle tubes, effectively ensuring the extraction efficiency of the bundle tubes.

[0030] 2. The present invention pre-connects multiple bundle tubes distributed at different positions in the goaf to the gas storage pipe, and controls the opening sequence through each ball valve, so that the gas at different positions in the goaf can be extracted. During the gas extraction process of multiple bundle tubes, this device can be realized without moving. In addition, this application uses underground wind power, which has no mechanical moving parts and does not require an external power supply. In the final stage of gas extraction, only the original gas negative pressure automatic gas extraction pump can realize the gas extraction process of the gas in multiple bundle tubes with different positions, different lengths and at the goaf port. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is the overall structural schematic diagram of an embodiment of the present invention;

[0032] Figure 2 is the layout schematic diagram of four pipeline adapters III in the embodiment of the present invention.

[0033] In the figure: 1-underground high-pressure air pipeline, 2-pipeline adapter I, 3-ball valve II, 4-Laval tube, 5-vacuum cavity, 6-ball valve I, 7-gas storage pipe, 8-ball valve III, 9-pipeline adapter II, 10-ball valve IV No. 1, 11-ball valve IV No. 2, 12-ball valve IV No. 3, 13-ball valve IV No. 4, 14-drainage ball valve, 15-pipeline adapter III No. 1, 16-pipeline adapter III No. 2, 17-pipeline adapter III No. 3, 18-pipeline adapter III No. 4, 19-drain pipe, 20-bundle tube No. 2, 21-bundle tube No. 1, 22-bundle tube No. 4, 23-bundle tube No. 3, 24-protective tube, 25-flowmeter. DETAILED DESCRIPTION OF THE INVENTION

[0034] The present invention will be further described below.

[0035] As Figure 1 shown, in the embodiment: The gas extraction device of this embodiment includes a Laval tube 4, an exhaust pipe and a gas storage pipe 7;

[0036] A vacuum cavity 5 is provided inside the exhaust pipe. An air inlet and an air outlet are respectively provided at both ends of the exhaust pipe, and an air extraction port is provided on the side of the exhaust pipe;

[0037] The air inlet end of the Laval tube 4 is connected to the underground high-pressure air pipeline 1 through a pipeline adapter 2; the air outlet end of the Laval tube 4 extends into the vacuum cavity 5 from the air inlet, and the outer surface of the Laval tube 4 is fixedly sealed with the air inlet; the Laval tube 4 is used to accelerate the airflow in the underground high-pressure air pipeline 1 and then discharge it into the vacuum cavity 5 and discharge it from the air outlet, so as to generate negative pressure in the vacuum cavity 5;

[0038] One end of the gas storage pipe 7 is connected to the vacuum cavity 5 through the air extraction port. The other end of the gas storage pipe 7 is provided with a drain pipe 19, and a drain ball valve 14 is installed on the drain pipe 19; a flow meter 25 is installed on the gas storage pipe 7 for monitoring the gas flow rate flowing through the gas storage pipe 7; the flow meter 25 is a pressure type flow meter. Adopting this structure not only has stable operation but also is convenient for installation. A pipeline adapter 2 and a pipeline adapter 3 are installed on the side of the gas storage pipe 7. The pipeline adapter 2 is close to one end of the gas storage pipe 7, and the pipeline adapter 3 is close to the other end of the gas storage pipe 7. The pipeline adapter 3 is used to connect the bundle tubes arranged in the goaf, so that the gas in the bundle tubes is extracted into the gas storage pipe 7; the pipeline adapter 2 is used to connect the gas negative pressure automatic gas sampling pump to collect the gas in the gas storage pipe 7; a ball valve 6 is installed at the connection between one end of the gas storage pipe 7 and the air extraction port. When the ball valve 6 is opened, the gas storage pipe 7 and the vacuum cavity 5 are connected and in a negative pressure state to extract the gas inside the bundle tubes. When closed, the gas storage pipe 7 retains the extracted gas in the gas storage pipe 7 and is collected by the gas negative pressure automatic gas sampling pump. A ball valve 2 is installed on the pipeline adapter 2, a ball valve 3 is installed on the pipeline adapter 2, and there are four pipeline adapters 3 in total, namely 1st pipeline adapter 3 15, 2nd pipeline adapter 3 16, 3rd pipeline adapter 3 17 and 4th pipeline adapter 3 18. The four pipeline adapters 3 are evenly distributed on the outer surface of the gas storage pipe 7 and are on the same horizontal plane. Ball valves 4 are installed on all four pipeline adapters 3, namely 1st ball valve 4 10, 2nd ball valve 4 11, 3rd ball valve 4 12 and 4th ball valve 4 13. Each ball valve is used to control the on-off of the pipeline where it is located.

[0039] As an improvement of the present invention, the outer surface of the Laval tube 4 and the air inlet are fixedly sealed through threads and a sealing ring. Adopting this connection method is not only convenient for installation but also has a good sealing effect.

[0040] The working method of the air extraction device in the above-mentioned embodiment specifically includes the following steps:

[0041] ① Initially, all the ball valves of this device are in the closed state. Four bundle tubes arranged at different positions in the gob area are respectively determined as the No. 1 bundle tube 21, the No. 2 bundle tube 20, the No. 3 bundle tube 22, and the No. 4 bundle tube 23. Among them, the No. 1 bundle tube 21 is connected to the gas storage pipe 7 through the No. 1 pipeline adapter three 15, the No. 2 bundle tube 20 is connected to the gas storage pipe 7 through the No. 2 pipeline adapter three 16, the No. 3 bundle tube 22 is connected to the gas storage pipe 7 through the No. 3 pipeline adapter three 17, and the No. 4 bundle tube 23 is connected to the gas storage pipe 7 through the No. 4 pipeline adapter three 18. The intake end of the Laval tube 4 is connected to the underground high-pressure air pipeline 1 through the pipeline adapter one 2;

[0042] ② Before starting work, first open the drain ball valve 14 and the ball valve one 6, and connect a negative pressure pressure gauge to the drain pipe 19. Then slowly open the ball valve two 3. The air flow in the underground high-pressure air pipeline 1 enters the Laval tube 4 and is accelerated by the Laval tube 4 and then discharged into the vacuum cavity 5. At this time, the high-speed air flow will compress the gas in the vacuum cavity 5 and discharge it from the exhaust port, causing a negative pressure in the vacuum cavity 5, and then a negative pressure is generated in the gas storage pipe 7. By observing the reading of the negative pressure pressure gauge until the reading no longer changes, it indicates that the negative pressure environment in the gas storage pipe 7 is stable at this time. Then close the drain ball valve 14 and remove the negative pressure pressure gauge;

[0043] ③ First, select the No. 1 bundle tube 21 as the bundle tube that needs to collect gas. Slowly open the No. 1 ball valve four 10 corresponding to the No. 1 bundle tube 21 to connect the No. 1 bundle tube 21 to the inside of the gas storage pipe 7. Since the inside of the gas storage pipe 7 is in a negative pressure environment, the port of the No. 1 bundle tube 21 in the gob area continuously extracts the surrounding gas. Adjust the opening degree of the No. 1 ball valve four 10 according to the reading of the flow meter 25 to ensure that the gas collection speed will not cause too much disturbance to the original flow field in the gob area;

[0044] ④ According to the length of the No. 1 bundle tube 21 and the reading of the flow meter 25, determine the gas collection time, so that the gas in the gob area enters the gas storage pipe 7 through the No. 1 bundle tube 21, and then the gas storage pipe 7 is filled with the internal gas of the gob area collected through the No. 1 bundle tube 21;

[0045] ⑤ During the entire gas extraction process, keep the gas storage pipe 7 in a vertical state so that the moisture mixed in the extracted gas converges to the bottom of the gas storage pipe 7;

[0046] ⑥ After reaching the gas collection time determined in step ④, close the ball valve one 6 to keep the collected gas in the gas storage pipe 7;

[0047] ⑦ Connect the gas negative pressure automatic gas pump to the pipeline adapter two 9, open the ball valve three 8, start the gas negative pressure automatic gas pump, and start collecting the gas in the gas storage pipe 7; at this time, the No. 1 ball valve four 10 corresponding to the No. 1 bundle tube 21 remains open to continuously supplement the gas in the No. 1 bundle tube 21 into the gas storage pipe 7;

[0048] ⑧ After continuously extracting for a period of time, turn off the gas negative pressure automatic gas sampling pump, ball valve three 8 and ball valve one 10 of No. 1, complete the gas collection work, and then open ball valve one 6 and the drain ball valve 14 to drain the accumulated water at the bottom of the gas storage pipe 7 through the drain pipe 19; thus completing the gas sampling process of the No. 1 bundle pipe 21;

[0049] ⑨ Then select the No. 2 bundle pipe 20 and repeat steps ③ to ⑧. Repeat the extraction of the No. 3 bundle pipe 22 and the No. 4 bundle pipe 23 respectively in this way, so as to realize the gas sampling process at different positions in the goaf.

[0050] Furthermore, a protective pipe 24 is provided outside each bundle pipe. Adding the protective pipe 24 can play a better protective effect on the bundle pipe and ensure the smoothness of the internal channel of the bundle pipe after being impacted externally.

[0051] The above is only the preferred embodiment of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A goaf bundle tube pneumatic negative pressure air extraction device, characterized in that, It includes a Laval nozzle, an exhaust pipe and a gas storage pipe; A vacuum cavity is provided inside the exhaust pipe. An air inlet and an air outlet are respectively provided at both ends of the exhaust pipe, and an air extraction port is provided on the side of the exhaust pipe; The air inlet end of the Laval nozzle is connected to the underground high-pressure air pipeline through a pipeline adapter one; the air outlet end of the Laval nozzle extends into the vacuum cavity from the air inlet, and the outer surface of the Laval nozzle is fixedly sealed with the air inlet. The Laval nozzle is used to accelerate the airflow in the underground high-pressure air pipeline and then discharge it into the vacuum cavity, and discharge it from the air outlet, so as to generate a negative pressure in the vacuum cavity; One end of the gas storage pipe is connected to the vacuum cavity through the air extraction port. The other end of the gas storage pipe is provided with a drain pipe, and a drain ball valve is installed on the drain pipe. A pipeline adapter two and a pipeline adapter three are installed on the side of the gas storage pipe. The pipeline adapter two is close to one end of the gas storage pipe, and the pipeline adapter three is close to the other end of the gas storage pipe. The pipeline adapter three is used to connect the bundle pipes arranged in the goaf, so that the gas in the bundle pipes is extracted into the gas storage pipe; the pipeline adapter two is used to connect the gas negative pressure automatic gas sampler to collect the gas in the gas storage pipe; a ball valve one is installed at the connection between one end of the gas storage pipe and the air extraction port. When the ball valve one is opened, the gas storage pipe is in a negative pressure state in communication with the vacuum cavity to extract the gas inside the bundle pipes. When it is closed, the gas storage pipe retains the extracted gas in the gas storage pipe and is collected by the gas negative pressure automatic gas sampler.

2. The gob bundle tube pneumatic negative pressure air extraction device according to claim 1, characterized in that, A ball valve two is installed on the pipeline adapter one.

3. The gob bundle tube pneumatic negative pressure air extraction device according to claim 1, characterized in that A ball valve three is installed on the pipeline adapter two.

4. The gob bundle tube pneumatic negative pressure air extraction device according to claim 1, characterized in that, A flowmeter is installed on the gas storage pipe to monitor the gas flow rate flowing through the gas storage pipe.

5. The gob bundle tube pneumatic negative pressure air extraction device according to claim 1, wherein There are four pipeline adapters three in total. The four pipeline adapters three are evenly distributed on the outer surface of the gas storage pipe and are on the same horizontal plane.

6. The gob bundle tube pneumatic negative pressure air extraction device according to claim 1, characterized in that, A ball valve four is installed on the pipeline adapter three.

7. The gob bundle tube pneumatic negative pressure air extraction device according to claim 4, wherein, The flowmeter is a pressure type flowmeter.

8. The gob bundle tube pneumatic negative pressure air extraction device according to claim 1, characterized in that, The outer surface of the Laval nozzle and the air inlet are fixedly sealed through threads and sealing rings.

9. A working method of the gob bundle tube pneumatic negative pressure air extraction device according to any one of claims 1 to 8, characterized in that, The specific steps are as follows: ① Initially, all the ball valves of this device are in the closed state. Multiple bundle pipes arranged at different positions in the goaf are respectively connected to the gas storage pipe through each pipeline adapter three, and the air inlet end of the Laval nozzle is connected to the underground high-pressure air pipeline through the pipeline adapter one; ② Before starting work, first open the drain ball valve and the ball valve one, and connect a negative pressure pressure gauge to the drain pipe. Then slowly open the ball valve two. The airflow in the underground high-pressure air pipeline enters the Laval nozzle and is accelerated by the Laval nozzle and then discharged into the vacuum cavity. At this time, the high-speed airflow will compress the gas in the vacuum cavity and discharge it from the air outlet, generating a negative pressure in the vacuum cavity, and then generating a negative pressure in the gas storage pipe. By observing the reading of the negative pressure pressure gauge until the reading no longer changes, it means that the negative pressure environment in the gas storage pipe is stable at this time. Then close the drain ball valve and remove the negative pressure pressure gauge; ③ First, select one of the multiple bundle pipes as the bundle pipe that needs to collect gas, and slowly open the corresponding ball valve four of this bundle pipe to make the bundle pipe communicate with the inside of the gas storage pipe. Since the inside of the gas storage pipe is in a negative pressure environment, the port of the bundle pipe in the goaf continuously extracts the surrounding gas at this time. Adjust the opening of the ball valve four according to the reading of the observed flowmeter to ensure that the gas collection speed will not cause too much disturbance to the original flow field in the goaf; ④Determine the gas sampling time according to the length of the bundle tube selected in step ③ and the reading of the flowmeter, so that the gas in the goaf passes through the bundle tube and enters the gas storage pipe, and then the gas storage pipe is filled with the internal gas of the goaf collected through the bundle tube; ⑤During the entire air extraction process, keep the gas storage pipe in a vertical state so that the moisture mixed in the extracted gas flows into the bottom of the gas storage pipe; ⑥After reaching the gas sampling time determined in step ④, close Ball Valve 1 so that the collected gas remains in the gas storage pipe; ⑦Connect the gas negative pressure automatic gas sampler to Pipe Connector 2, open Ball Valve 3, start the gas negative pressure automatic gas sampler, and start collecting the gas in the gas storage pipe; at this time, Ball Valve 4 corresponding to this bundle tube remains open so that the gas in the bundle tube continues to be supplemented into the gas storage pipe; ⑧After continuous extraction for a period of time, turn off the gas negative pressure automatic gas sampler, Ball Valve 3 and Ball Valve 4 to complete the gas collection work, and then open Ball Valve 1 and the drain ball valve to drain the accumulated water at the bottom of the gas storage pipe through the drain pipe; thus, the gas sampling process of the current bundle tube is completed; ⑨Select another bundle tube and repeat steps ③ to ⑧. After repeating many times in this way, the gas extraction of each bundle tube can be carried out separately to realize the gas sampling process at different positions in the goaf.

10. The working method of the gob bundle tube pneumatic negative pressure air extraction device according to claim 9, characterized in that, A protective tube is provided outside the bundle tube.

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