Coal seam sampling device for acquiring actual gas pressure

Abstract

The utility model discloses a coal seam sampling device for acquiring actual gas pressure, which comprises a coal sample sampler for sampling a coal seam, and a connecting part connected with a drill rod of a drilling machine is arranged at the rear end of the coal sample sampler; a drill bit used for coal seam drilling is arranged at the front end of the coal sample sampler, a pressure sensor used for obtaining coal seam gas pressure is installed in the coal sample sampler, the pressure sensor is connected with a single-chip microcomputer used for storing pressure data, the single-chip microcomputer is connected with a wireless communication module, and the wireless communication module, the pressure sensor and the single-chip microcomputer are all connected with a storage battery. The coal sample sampler and the drill bit are highly integrated, the pressure sensor is integrated, pressure data measured during sampling in a drill hole can be stored in the single chip microcomputer, coal seam gas measurement work is completed during sampling, and compared with gas pressure obtained after a coal sample is taken back to a laboratory and then measured, the coal seam gas pressure measuring device is more accurate and reliable, and the coal seam gas pressure measuring device is convenient to use. And more reliable coal seam gas pressure data is provided for coal seam gas exploration and mining.

Description

Technical Field

[0001] The utility model relates to the technical field of coal mine operations, in particular to coal seam sampling technology. Background Art

[0002] Coal seam sampling is to take out some representative coal samples in the coal seam, so as to analyze and test the coal samples, determine the coal type, coal quality characteristics, gas occurrence conditions and their variation laws of the mineable coal seams, and provide reliable data for the development and utilization of the mine.

[0003] Coal seam gas pressure is the basic data for gas exploration and mining. The existing coal seam sampling technology is to use a drill rig to drill a hole, use a sampling device in the hole to seal and take out the coal sample, and then analyze and test the coal sample. The following factors determine that it is difficult to obtain very accurate coal seam gas pressure by the existing sampling and testing technologies:

[0004] 1. Gas loss occurs during the sampling process, and there is partial gas loss before successful sampling. The gas pressure in the coal sample is often significantly lower than the actual gas pressure in the coal seam.

[0005] 2. There is an interval between sampling and analyzing and testing the coal sample. Sometimes the interval is relatively long. During the waiting period, the gas in the coal sample will continue to escape; even if the coal sample is sealed in a closed container, when the coal sample is taken out in the laboratory and installed on the test equipment (such as a coal sample gripper), a large part of the gas that escapes from the coal sample and is enclosed in the closed container will be lost.

[0006] 3. After sampling, the coal sample is exposed to an environment with a large difference in physical environment (temperature, stress, humidity, etc.) from the coal seam, which may cause an obvious change (depending on the difference between the environmental conditions and the formation conditions) in the gas pressure in the coal sample. Summary of the Utility Model

[0007] The purpose of the utility model is to provide a coal seam sampling device for obtaining the actual gas pressure, which is used to directly obtain the coal seam gas pressure while sampling.

[0008] To achieve the above purpose, the coal seam sampling device for obtaining the actual gas pressure of the utility model includes a coal sample sampler for coal seam sampling. A connecting part for connecting with the drill pipe of the drill rig is arranged at the rear end of the coal sample sampler; a drill bit for drilling the coal seam is arranged at the front end of the coal sample sampler.

[0009] A pressure sensor for obtaining the coal seam gas pressure is installed in the coal sample sampler. The pressure sensor is connected with a single-chip microcomputer for storing pressure data. The single-chip microcomputer is connected with a wireless communication module. The wireless communication module, the pressure sensor and the single-chip microcomputer are all connected with a storage battery.

[0010] Taking the forward direction during drilling as the forward direction;

[0011] The coal sample sampler includes an outer tube. A number of radial connecting plates are connected to the circumferential inner wall of the outer tube. An axial connecting block is fixedly connected to the inner surface of the rear wall of the outer tube. An inner tube is arranged inside the outer tube. The inner tube is connected to the outer tube through the radial connecting plates and the axial connecting block and there is a gap between the two.

[0012] An installation groove for threaded cooperation with a drill pipe is provided at the rear end of the outer tube, and the opening direction of the installation groove faces backward. The outer tube and the inner tube form a fixed tube. The front end of the fixed tube is threadedly connected to the drill bit. A sampling hole is provided in the middle of the drill bit.

[0013] The inner tube is used to load a sampling tube. An electric ball valve for opening or closing the sampling tube is provided at the open front end of the sampling tube. The electric ball valve is connected to a single-chip microcomputer and a storage battery.

[0014] A sampling valve is provided at the sampling hole. The sampling valve is used to control the open or closed state of the sampling hole so as to prevent coal body from entering the sampling hole before reaching the sampling position.

[0015] The gap between the outer tube and the inner tube forms a water passing cavity. A water passing port communicating with the water passing cavity is provided at the bottom of the installation groove.

[0016] A water outlet communicating with the water passing cavity is provided on the surface of the drill bit. The sampling valve includes a first valve plate structure and a second valve plate structure.

[0017] The first valve plate structure and the second valve plate structure are symmetrically arranged. Both include a valve plate for closing the sampling hole. The valve plate is arranged in a valve plate groove inside the drill bit. The valve plate groove extends radially.

[0018] The valve plate is radially outwardly pressed with a radial spring. The other end of the radial spring is outwardly pressed against the wall of the valve plate groove. The radially inner end of the valve plate is hinged with a reaction rotation device. The reaction rotation device is connected to the fixed structure of the drill bit. The reaction rotation device is used to open or close the sampling hole under the action of water flow.

[0019] The reaction rotation device includes an installation shaft fixed to the fixed structure of the drill bit. There are two installation shafts arranged in parallel at intervals. The two installation shafts are respectively a first installation shaft and a second installation shaft. A first gear is installed on the first installation shaft. A second gear is installed on the second installation shaft. The first gear is higher than the second gear. The lower part of the first gear meshes with the upper part of the second gear. An upper gear ring and a lower gear ring are sleeved outside the first gear and the second gear. The first gear meshes with the upper gear ring. The second gear meshes with the lower gear ring. The upper gear ring is connected with an upper transmission plate. The lower gear ring is connected with a lower transmission plate. The upper transmission plate extends radially into the water outlet and is used to bear the water pressure. The lower transmission plate extends to the sampling hole and is hinged with the valve plate.

[0020] The rotation space of the lower transmission plate is located at the sampling hole. There is a cavity in the drill bit for the upper transmission plate to rotate.

[0021] The upper driving plate is press-fitted with an axial spring, and the other end of the axial spring is press-fitted with the fixing structure of the drill bit.

[0022] A first sealing disc is rotatably clamped at the rear end of the sampling tube. The first sealing disc is rotatably clamped with a second sealing disc in the backward direction. An anterior analysis hole that penetrates through from front to back is eccentrically arranged on the first sealing disc, and a posterior analysis hole that penetrates through from front to back is eccentrically arranged on the second sealing disc; the anterior analysis hole and the posterior analysis hole are arranged correspondingly.

[0023] The utility model has the following advantages:

[0024] In the utility model, the coal sample sampler and the drill bit are highly integrated, and a pressure sensor is integrated. The pressure data measured during sampling in the drill hole can be stored in the single-chip microcomputer, and the coal seam gas measurement work is completed while sampling. Compared with the gas pressure obtained by measuring the coal sample after retrieving it to the laboratory, it is more accurate and reliable, providing more reliable coal seam gas pressure data for coal seam gas exploration and exploitation.

[0025] After drilling to the sampling position, open the electric ball valve and continue to push forward to load the coal sample into the inner tube. Close the electric ball valve to cut off and seal the coal sample. After withdrawing the drill pipe from the drill hole, the inner tube can be conveniently taken out for testing the coal sample, and it is very convenient to use.

[0026] The reverse rotation device has a simple structure. When the water pressure is increased, the upper driving plate can conveniently rotate forward under the impact of the water flow. Through the upper gear ring, the first gear, the second gear, the lower gear ring and the lower driving plate, the valve plate is driven to move radially outward in the valve plate groove, so as to leave the sampling hole and open the sampling hole for sampling. After sampling is completed, close the water flow or reduce the water pressure. Under the action of the axial spring and the radial spring, the reverse rotation device returns to its original position and closes the sampling hole again.

[0027] The reverse rotation device and the valve plate can close the sampling hole during drilling and open the sampling hole after drilling in place for sampling, avoiding coal from entering the sampling hole during drilling and improving the sampling purity at a specific position.

[0028] The anterior analysis hole and the posterior analysis hole are arranged correspondingly. The anterior analysis hole and the posterior analysis hole can be made to communicate by rotating the first sealing disc and the second sealing disc and are used to connect the analysis experimental device. Before the experiment, the anterior analysis hole and the posterior analysis hole are made not to communicate with each other by rotating the first sealing disc and the second sealing disc to keep the sampling tube in a sealed state. Brief Description of the Drawings

[0029] Figure 1 is the structural schematic diagram of the utility model.

[0030] Figure 2 is Figure 1 the enlarged view at A in

[0031] Figure 3 is Figure 1 the left view of

[0032] Figure 4 is the structural schematic diagram of the reaction rotation device.

[0033] Figure 5 is Figure 4 the A-A sectional view of

[0034] Figure 6 is the electrical control structural schematic diagram of the present utility model. Specific implementation mode

[0035] Embodiment 1

[0036] As Figure 1 and Figure 6 shown, the coal seam sampling device for obtaining the actual gas pressure in this embodiment includes a coal sample sampler for coal seam sampling. A connection part for connecting with the (hollow) drill pipe of the drill rig is provided at the rear end of the coal sample sampler; a drill bit 1 for drilling the coal seam is provided at the front end of the coal sample sampler. A pressure sensor 2 for obtaining the coal seam gas pressure is embedded and installed in the coal sample sampler. The pressure sensor 2 is connected with a single-chip microcomputer 3 (such as the 51 single-chip microcomputer 3) for storing pressure data. The single-chip microcomputer 3 is connected with a wireless communication module 4. The wireless communication module 4, the pressure sensor 2 and the single-chip microcomputer 3 are all connected with a storage battery 5.

[0037] In the present utility model, the coal sample sampler and the drill bit 1 are highly integrated, and the pressure sensor 2 is integrated. The pressure data measured while sampling during drilling can be stored in the single-chip microcomputer 3, so as to complete the coal seam gas measurement work while sampling. Compared with the gas pressure obtained by measuring after taking the coal sample back to the laboratory, it is more accurate and reliable, providing more reliable coal seam gas pressure data for coal seam gas exploration and exploitation.

[0038] The present utility model takes the forward direction during drilling as the forward direction;

[0039] The coal sample sampler includes an outer pipe 6. A plurality of radial connecting plates 7 are connected to the circumferential inner wall of the outer pipe 6. An axial connecting block 8 is fixedly connected to the inner surface of the rear wall of the outer pipe 6. An inner pipe 9 is arranged in the outer pipe 6. The inner pipe 9 is connected with the outer pipe 6 through the radial connecting plates 7 and the axial connecting block 8 and there is a gap between the two;

[0040] An installation groove 10 for threadedly matching with the drill pipe (the drill pipe correspondingly has an external thread) is provided at the rear end of the outer pipe 6. The opening direction of the installation groove 10 faces backward; the outer pipe 6 and the inner pipe 9 form a fixed pipe. The front end of the fixed pipe is threadedly connected with the drill bit 1. A sampling hole 11 is provided in the middle of the drill bit 1.

[0041] The inner tube 9 is used to hold the sampling tube 12. An electric ball valve 13 for opening or closing the sampling tube 12 is provided at the open front end of the sampling tube 12. The electric ball valve 13 is connected to the single-chip microcomputer 3 and the storage battery 5.

[0042] After drilling to the sampling position, open the electric ball valve 13 and then continue to push forward to load the coal sample into the inner tube 9. Closing the electric ball valve 13 can cut and seal the coal sample. After withdrawing the drill pipe from the borehole, the inner tube 9 can be conveniently taken out for testing the coal sample, which is very convenient to use.

[0043] During the experiment, place the sampling tube 12 into the inner tube 9, close the electric ball valve 13, install the drill bit 1 at the front end of the coal sample sampler, and connect the rear end of the coal sample sampler to the drill pipe of the drill rig (or other drilling equipment) through the connecting part; start the drill rig and drill a borehole into the coal seam. When reaching the predetermined sampling depth, open the electric ball valve 13. When continuing to drill forward, coal enters the sampling tube 12 to complete the sampling. At the same time of sampling, the pressure sensor 2 measures the gas pressure in real time and stores it in the memory of the single-chip microcomputer 3, so as to obtain more accurate gas pressure data compared with measuring the gas pressure after taking out the coal sample, and better guide the subsequent coal seam gas exploration and mining operations. After sampling, close the electric ball valve 13 (the staff can close the electric ball valve 13 at the drill rig through the wireless communication module 4, or simply set the closing time of the electric ball valve 13 in the single-chip microcomputer 3 before drilling). When the electric ball valve 13 is closed, the coal sample is cut. Withdraw the drill pipe from the borehole, remove the drill bit 1, pull out the sampling tube 12, and test the coal sample.

[0044] Embodiment 2

[0045] As Figures 1 to 6 shown, the difference between this embodiment and Embodiment 1 is that: a sampling valve is provided at the sampling hole 11. The sampling valve is used to control the opening or closing state of the sampling hole 11 to prevent coal body from entering the sampling hole 11 before reaching the sampling position.

[0046] The gap between the outer tube 6 and the inner tube 9 forms a water passing cavity 14. A water passing port 15 communicating with the water passing cavity 14 is provided at the bottom of the installation groove 10 (i.e., the rear wall of the outer tube 6);

[0047] A water outlet 16 communicating with the water passing cavity 14 is provided on the surface of the drill bit 1. The sampling valve includes a first valve plate structure and a second valve plate structure;

[0048] The first valve plate structure and the second valve plate structure are symmetrically arranged, and both include a valve plate 17 for closing the sampling hole 11. The valve plate 17 is arranged in a valve plate groove in the drill bit 1, and the valve plate groove extends radially;

[0049] A radial spring 18 is press-fitted radially outward on the valve plate 17, and the other end of the radial spring 18 presses outward against the groove wall of the valve plate groove; a reaction rotation device 19 is hinged to the radially inner end of the valve plate 17, and the reaction rotation device 19 is connected to the fixed structure of the drill bit 1. The reaction rotation device 19 is used to open or close the sampling hole 11 under the action of water flow.

[0050] As Figure 4 and Figure 5 shown, and referring to Figures 1 to 3 , the reaction rotation device 19 includes a mounting shaft fixed to the fixed structure of the drill bit 1. There are two mounting shafts arranged in parallel at intervals. The two mounting shafts are the first mounting shaft 20 and the second mounting shaft 21 respectively. A first gear 22 is mounted on the first mounting shaft 20, and a second gear 23 is mounted on the second mounting shaft 21. The first gear 22 is higher than the second gear 23, and the lower part of the first gear 22 meshes with the upper part of the second gear 23; an upper gear ring 24 and a lower gear ring 25 are sleeved outside the first gear 22 and the second gear 23. The first gear 22 meshes with the upper gear ring 24, and the second gear 23 meshes with the lower gear ring 25; the teeth of the upper gear ring 24 and the lower gear ring 25 are both arranged on the circumferential inner surface. The upper gear ring 24 is connected with an upper transmission plate 26, and the lower gear ring 25 is connected with a lower transmission plate 27; the upper transmission plate 26 extends radially into the water outlet 16 and is used to bear the water pressure, and the lower transmission plate 27 extends to the sampling hole 11 and is hinged to the valve plate 17;

[0051] The rotation space of the lower transmission plate 27 is located at the sampling hole 11, and there is a cavity in the drill bit 1 for the upper transmission plate 26 to rotate;

[0052] An axial spring 28 is press-fitted on the upper transmission plate 26, and the other end of the axial spring 28 presses against the fixed structure of the drill bit 1.

[0053] The structure of the reaction rotation device 19 is simple. When the water pressure increases, the upper transmission plate 26 can easily rotate forward under the impact of the water flow, and drives the valve plate 17 to move radially outward in the valve plate groove through the upper gear ring 24, the first gear 22, the second gear 23, the lower gear ring 25 and the lower transmission plate 27, so as to leave the sampling hole 11 and open the sampling hole 11 for sampling. After sampling is completed, the water flow is closed or the water pressure is reduced. Under the action of the axial spring 28 and the radial spring 18, the reaction rotation device 19 returns to its original position and closes the sampling hole 11 again.

[0054] The reaction rotation device 19 and the valve plate 17 can close the sampling hole 11 during drilling, and open the sampling hole 11 after drilling in place for sampling, avoiding coal from entering the sampling hole 11 during drilling and improving the sampling purity at specific positions.

[0055] A first sealing disk 29 is rotatably clamped to the rear end of the sampling pipe 12. A second sealing disk 30 is rotatably clamped to the rear of the first sealing disk 29. An anterior analysis hole 31 that is transparent from front to back is eccentrically provided on the first sealing disk 29. A posterior analysis hole 32 that is transparent from front to back is eccentrically provided on the second sealing disk 30. The anterior analysis hole 31 and the posterior analysis hole 32 are correspondingly arranged.

[0056] The anterior analysis hole 31 and the posterior analysis hole 32 are correspondingly arranged. By rotating the first sealing disk 29 and the second sealing disk 30, the anterior analysis hole 31 and the posterior analysis hole 32 can be connected to each other and used to connect the analysis experimental device. Before the experiment, by rotating the first sealing disk 29 and the second sealing disk 30, the anterior analysis hole 31 and the posterior analysis hole 32 are made non - communicating with each other, so as to keep the sampling pipe 12 in a sealed state.

[0057] During the experiment, the installation groove 10 is thread - connected to the drill pipe as the installation part in the first embodiment. During the experiment, the sampling pipe 12 is inserted into the inner pipe 9. The electric ball valve 13 is closed. The drill bit 1 is installed at the front end of the coal sample sampler. The rear end of the coal sample sampler is connected to the drill pipe of the drill rig (or other drilling equipment) through the installation groove 10. When the sampling valve is not under water pressure, it is in a closed state. At this time, the valve plate 17 of the first valve plate structure 17 and the second valve plate structure 17 closes the sampling hole 11.

[0058] Connect the water injection source (such as a water pump) to the water - passing port 15 through a water injection pipe. Start the drill rig and drill a hole in the coal seam. At the same time, inject water through the water - passing port 15, the water - passing cavity 14 and the water outlet 16 to the drill bit 1 to prevent the temperature of the drill bit 1 from being too high. During this process, the water injection pressure is relatively low, and it is only necessary to achieve the cooling of the drill bit 1. Under the resistance of the axial spring 28 to the water flow impact force, the reaction rotary device 19 does not act.

[0059] When drilling reaches the predetermined sampling depth, open the electric ball valve 13. The water pressure of the water injection is increased. The pressure of the water flow impacting on the upper transmission plate 26 increases, thus forcing the upper transmission plate 26 to rotate forward. The upper transmission plate 26 drives the lower transmission plate 27 to rotate forward through the upper gear ring 24, the first gear 22, the second gear 23 and the lower gear ring 25, thereby driving the valve plate 17 to move radially outward in the valve plate groove and away from the sampling hole 11 to open the sampling hole 11 for sampling.

[0060] After sampling is completed, turn off the water flow or reduce the water pressure. Under the action of the axial spring 28 and the radial spring 18, the reaction rotary device 19 returns to its original position and closes the sampling hole 11 again.

[0061] When drilling forward continuously, coal enters the sampling pipe 12 to complete sampling. During sampling, the pressure sensor 2 measures the gas pressure in real time and stores it in the memory of the single-chip microcomputer 3, so as to obtain more accurate gas pressure data compared with measuring the gas pressure after taking out the coal sample, and better guide the subsequent coal seam gas exploration and mining operations. Close the water flow or reduce the water pressure. Under the action of the axial spring 28 and the radial spring 18, the reaction rotation device 19 returns to its original position and closes the sampling hole 11 again. After sampling, close the electric ball valve 13 (the staff can close the electric ball valve 13 at the drill by means of the wireless communication module 4. Of course, it can also simply set the closing time of the electric ball valve 13 in the single-chip microcomputer 3 before drilling). When the electric ball valve 13 is closed, the coal sample is cut off. Withdraw the drill pipe from the borehole, remove the drill bit 1, pull out the sampling pipe 12, rotate the first sealing disc 29 and the second sealing disc 30 to make the front analysis hole 31 and the rear analysis hole 32 communicate correspondingly. At this time, connect the rear analysis hole 32 with a pipeline, and the coal sample can be subjected to an analysis test. Before the analysis test, the coal sample is in a continuous sealed state and there is no process of taking out the coal sample, so the gas loss in the coal sample is small, making the test result more accurate.

[0062] The above embodiments are only used to illustrate rather than limit the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the present invention can still be modified or equivalently replaced, and any modification or partial replacement without departing from the spirit and scope of the present invention shall be covered by the scope of the claims of the present invention.

Claims

1. A coal seam sampling device for obtaining actual gas pressure, comprising a coal sampler for coal seam sampling, a connection portion for connecting to a drill rod of a drilling rig is provided at the rear end of the coal sampler, and a drill bit for drilling a coal seam is provided at the front end of the coal sampler. Features: A pressure sensor for obtaining coal seam gas pressure is installed in the coal sample sampler. The pressure sensor is connected to a single-chip microcomputer for storing pressure data. The single-chip microcomputer is connected to a wireless communication module. The wireless communication module, the pressure sensor and the single-chip microcomputer are all connected to a battery.

2. The coal seam sampling device for obtaining actual gas pressure according to claim 1, characterized in that: The forward direction during drilling is regarded as the forward direction; The coal sampler comprises an outer tube, a plurality of radial connection plates are connected to the circumferential inner wall of the outer tube, an axial connection block is fixedly connected to the inner surface of the rear wall of the outer tube, an inner tube is arranged inside the outer tube, and the inner tube is connected to the outer tube through the radial connection plates and the axial connection block with a gap between the two; The rear end of the outer tube is provided with a mounting groove for matching with the drill rod thread, and the opening direction of the mounting groove faces backward; the outer tube and the inner tube form a fixed tube, the front end of the fixed tube is threadedly connected to the drill bit, and a sampling hole is provided in the middle of the drill bit. The inner tube is used for loading the sampling tube. The front end opening of the sampling tube is provided with an electric ball valve for opening or closing the sampling tube. The electric ball valve is connected with the single chip microcomputer and the storage battery.

3. The coal seam sampling device for obtaining actual gas pressure according to claim 2, characterized in that: A sampling valve is provided at the sampling hole, and the sampling valve is used to control the opening or closing state of the sampling hole so as to prevent coal from entering the sampling hole before reaching the sampling position.

4. The coal seam sampling device for obtaining actual gas pressure according to claim 3, characterized in that: The gap between the outer tube and the inner tube forms a water passage cavity, and the bottom of the installation groove is provided with a water passage port communicating with the water passage cavity; A water outlet communicating with the water passage cavity is provided on the surface of the drill bit, and the sampling valve comprises a first valve plate structure and a second valve plate structure; The first valve plate structure and the second valve plate structure are symmetrically arranged, and both include a valve plate for closing the sampling hole, the valve plate is arranged in a valve plate groove in the drill bit, and the valve plate groove extends in the radial direction; A radial spring is pressed radially outwardly on the valve plate, and the other end of the radial spring is pressed outwardly against the groove wall of the valve plate groove; a reaction rotation device is hinged at the radial inner end of the valve plate, and the reaction rotation device is connected to the fixed structure of the drill bit. The reaction rotation device is used to open or close the sampling hole under the action of water flow.

5. The coal seam sampling device for obtaining actual gas pressure according to claim 4, characterized in that: The counter-rotating device comprises a mounting shaft fixed on the fixed structure of the drill bit, two mounting shafts are arranged in parallel and spaced apart, the two mounting shafts are respectively a first mounting shaft and a second mounting shaft, a first gear is mounted on the first mounting shaft, a second gear is mounted on the second mounting shaft, the first gear is higher than the second gear, and the lower part of the first gear is meshed with the upper part of the second gear; an upper gear ring and a lower gear ring are arranged outside the first gear and the second gear, the first gear is meshed with the upper gear ring, and the second gear is meshed with the lower gear ring; the upper gear ring is connected to an upper transmission plate, and the lower gear ring is connected to a lower transmission plate; the upper transmission plate extends radially into the water outlet and is used to withstand water pressure, and the lower transmission plate extends to the sampling hole and is hinged to the valve plate; The rotation space of the lower transmission plate is located at the sampling hole, and the drill bit has a cavity for the upper transmission plate to rotate; An axial spring is pressed onto the upper transmission plate, and the other end of the axial spring is pressed onto the fixed structure of the drill bit.

6. The coal seam sampling device for obtaining actual gas pressure according to any one of claims 2 to 5, characterized in that: A first sealing disk is rotatably connected to the rear end of the sampling tube, and a second sealing disk is rotatably connected to the first sealing disk. A front analytical hole that is transparent front to back is eccentrically provided on the first sealing disk, and a rear analytical hole that is transparent front to back is eccentrically provided on the second sealing disk; the front analytical hole and the rear analytical hole are arranged correspondingly.

Images