Coal bed gas detection sampling device

Abstract

The invention discloses a coal bed gas detecting and sampling device, which belongs to the field of detecting and sampling devices and comprises a lower detecting tube, a lower sealing bag and an upper sealing bag are arranged at the lower end of the lower detecting tube, an expansion supporting mechanism is arranged between the lower sealing bag and the upper sealing bag, and the expansion supporting mechanism is linked with the expansion action of the upper sealing bag through a connecting rod. An air inlet hole and a filtering mechanism are arranged on the lower exploring pipe, the lower exploring pipe is communicated with an exhaust fan through a pipeline, the exhaust fan is communicated with the sampling bottle, a main air supply pipe is arranged in the lower exploring pipe, the main air supply pipe is communicated with an external air source, and a lowering mechanism is arranged above the sampling well. By designing a multi-cavity bag structure, reliable sealing in a complex coal seam is achieved; by means of the linkage design of the double-sealing bag and the expansion supporting mechanism, sealing is formed, meanwhile, active and rigid supporting is provided for the hole wall of the sampling cavity, coal deformation and collapse are effectively resisted, and the stability of the volume of the sampling cavity is ensured.

Description

Technical Field

[0001] This invention relates to the field of detection and sampling devices, and more particularly to a coalbed methane detection and sampling device. Background Technology

[0002] Coalbed methane, commonly known as "gas," is an unconventional natural gas resource found in coal seams and coal-bearing strata. Accurate exploration and sampling analysis are crucial for assessing reservoir potential, developing extraction plans, and preventing gas disasters. Currently, downhole exploration and sampling of coalbed methane primarily relies on lowering exploration and sampling equipment into the target coal seam through boreholes, creating an isolated chamber using packers, and then measuring gas parameters and collecting samples.

[0003] However, existing coalbed methane detection and sampling devices, especially in their mechanical structure, have significant defects that severely restrict the accuracy and reliability of the sampling data. These defects are mainly reflected in the following aspects:

[0004] 1. Poor sealing reliability; samples are easily contaminated.

[0005] Existing devices mostly employ single-bag or double-bag packing technology, with the bag being a single, annular cavity. During pressurization and expansion, the bag preferentially expands in the direction of least resistance within the borehole, making it difficult to achieve uniform adhesion to the borehole wall in soft, fractured, or highly irregular coal seams. This easily leads to leakage channels forming between the bag and the borehole wall, allowing gases from the upper and lower parts of the borehole (such as shaft air and gases from adjacent layers) to mix into the sampling chamber, resulting in distorted samples that cannot represent the true gas composition of the target coal seam.

[0006] 2. Lack of effective support and insufficient stability of the sampling chamber.

[0007] Traditional double-bag structures form a sampling chamber between the two bags. However, in mechanically weak coal seams, this unsupported section of the coal wall is prone to collapse or deformation during negative pressure sampling. The collapse of the coal seam not only blocks the sampling inlet and generates a large amount of coal dust, but also alters the effective volume of the sampling chamber, leading to inaccurate gas parameter measurements and potentially jamming the equipment, causing underground accidents.

[0008] In summary, existing coalbed methane detection and sampling devices suffer from the aforementioned inherent defects in their mechanical structure, making it difficult to obtain high-fidelity and reliable coalbed methane samples and in-situ detection data under complex coal seam conditions. Summary of the Invention

[0009] The purpose of this invention is to provide a coalbed methane detection and sampling device that solves the problems of poor sealing reliability, lack of effective support, and insufficient stability of the sampling chamber in existing devices.

[0010] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0011] This invention discloses a coalbed methane detection and sampling device, comprising a lower probe, a lower sealing bag and an upper sealing bag at the lower end of the lower probe, an expansion support mechanism between the lower and upper sealing bags, the expansion support mechanism being linked to the expansion action of the upper sealing bag via a connecting rod, a plurality of air inlets being provided on the lower probe and between the lower and upper sealing bags, a filter mechanism being provided outside the air inlets, the lower probe being connected to a blower via a pipeline, the blower being connected to a sampling bottle, a main air supply pipe for inflating the lower and upper sealing bags being provided inside the lower probe, the main air supply pipe being connected to an external air source, and a lowering mechanism for placing the lower probe into the sampling well being provided above the sampling well.

[0012] Furthermore, the lower sealing bag and the upper sealing bag have the same structure, and both the lower sealing bag and the upper sealing bag are configured as multi-chamber bags.

[0013] Furthermore, the interior of the lower sealing bag is provided with a plurality of first diaphragms along the axial direction. The plurality of first diaphragms divide the interior space of the lower sealing bag into a plurality of annular chambers. Each of the annular chambers is provided with a plurality of second diaphragms, and the plurality of second diaphragms divide the annular chamber into a plurality of sector-shaped sub-chambers.

[0014] Furthermore, the main gas supply pipe is provided with several branch gas supply pipes, each of which corresponds to one of the sector-shaped sub-chambers, and each branch gas supply pipe is provided with a miniature solenoid valve.

[0015] Furthermore, the expansion support mechanism includes a fixed mounting base and a movable mounting base. The fixed mounting base is fixedly mounted on the lower probe tube, and the movable mounting base is slidably mounted on the lower probe tube. Several folding frames are evenly distributed in a circle on the outer side of the fixed mounting base and the movable mounting base. A support plate is provided on the other side of the folding frame. A limiting block for limiting the movable end of the folding frame is provided on the inner side of the support plate. The movable mounting base is linked to the expansion action of the upper sealing bag through a connecting rod.

[0016] Furthermore, the folding frame includes two folding rods hinged together in the middle, forming an X-shaped structure. The two inner ends of the X-shaped structure are respectively hinged to the fixed mounting base and the movable mounting base. The lower outer end of the X-shaped structure is hinged to the support plate, and the upper outer end of the X-shaped structure is slidably connected to the limiting block.

[0017] Furthermore, the filtering mechanism includes an annular mounting frame, on which a filter screen is provided, and on the outer circumference of the mounting frame are a plurality of connecting seats, which are connected to the outer wall of the lower probe tube through a locking assembly.

[0018] A fixed seat is provided on the outer wall of the lower probe. A threaded rod is rotatably mounted on the fixed seat via a pin. A U-shaped groove matching the threaded rod is provided on the connecting seat. The threaded rod is rotated into the U-shaped groove and locked in place by a locking nut.

[0019] Furthermore, the lowering mechanism includes a support frame, on which a rotating sleeve is provided. A drive assembly for driving the rotating sleeve to rotate is provided on one side of the rotating sleeve. An extension tube is provided at the top of the lower probe tube. The extension tube is threadedly connected to the rotating sleeve. The rotational movement of the rotating sleeve drives the extension tube to move downward.

[0020] Furthermore, the drive assembly includes a first bevel gear disposed on the outside of the rotating sleeve, a second bevel gear meshing with the first bevel gear disposed on the support frame, a drive motor disposed on the support frame, a first synchronous pulley disposed on the output shaft of the drive motor, an auxiliary rotating shaft disposed on the support frame, a second synchronous pulley and a third synchronous pulley disposed on the auxiliary rotating shaft, a fourth synchronous pulley disposed at the other end of the central shaft of the second bevel gear, the first synchronous pulley being connected to the second synchronous pulley via a first synchronous belt, and the third synchronous pulley being connected to the fourth synchronous pulley via a second synchronous belt.

[0021] Furthermore, the support frame is provided with an anti-rotation seat, the anti-rotation seat is provided with a guide key, the extension tube is provided with a keyway that matches the guide key, and the diameter of the through hole of the anti-rotation seat is larger than the outer diameter of the extension tube.

[0022] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0023] This invention achieves reliable sealing in complex coal seams by designing a multi-chamber bag structure. This structure has inherent redundancy and safety characteristics. Even if one or more sub-chambers fail due to rupture, an effective sealing state can be maintained by isolating the faulty unit and compensating for the pressure of adjacent units, thus completely solving the problem of "one point of damage, overall failure" in traditional bags.

[0024] This invention, through the linkage design of a double-sealed bladder and an intermediate rigid expansion support mechanism, provides active and rigid support to the pore wall of the sampling chamber while forming a seal. This effectively resists coal deformation and collapse, ensuring the stability of the sampling chamber volume. This provides a crucial physical environment for obtaining accurate in-situ gas pressure parameters and undisturbed gas samples, greatly improving the accuracy of the detection data and the representativeness of the samples. Attached Figure Description

[0025] The present invention will be further described below with reference to the accompanying drawings.

[0026] Figure 1 This is a front view of the coalbed methane detection and sampling device of the present invention;

[0027] Figure 2 This is a cross-sectional view of the lower probe, lower sealing bladder, upper sealing bladder, and expansion support mechanism of the present invention.

[0028] Figure 3 This is a schematic diagram of the structure of the sealing bag of the present invention;

[0029] Figure 4 This is a three-dimensional structural diagram of the expansion support mechanism of the present invention;

[0030] Figure 5 for Figure 1 Enlarged view of point A in the middle;

[0031] Figure 6 This is a three-dimensional structural diagram of the locking component assembly of the present invention;

[0032] Figure 7 This is a three-dimensional structural diagram of the lowering mechanism of the present invention;

[0033] Figure 8 This is a schematic diagram of the structure of the driving component of the present invention;

[0034] Figure 9 This is a schematic diagram of the extended tube and anti-rotation seat of the present invention.

[0035] Explanation of reference numerals in the attached drawings: 1. Lower probe; 1-1. Air inlet; 2. Lower sealing bag; 2-1. First diaphragm; 2-2. Second diaphragm; 3. Upper sealing bag; 4. Main air supply pipe; 5. Branch air supply pipe; 6. Expansion support mechanism; 6-1. Fixed mounting base; 6-2. Movable mounting base; 6-3. Folding frame; 6-4. Support plate; 6-5. Limiting block; 7. Connecting rod; 8. Filtering mechanism; 8-1. Mounting frame; 8-2. Filter screen; 8-3. Connecting base; 8-4. Locking assembly; 8-4-1. Threaded rod; 8-4-2. Lock 9. Tightening nut; 10. Exhaust fan; 11. Sampling bottle; 11. Lowering mechanism; 11-1. Base frame; 11-2. Vertical support; 11-3. Inclined support; 11-4. Rotating sleeve; 11-5. First bevel gear; 11-6. Second bevel gear; 11-7. Drive motor; 11-8. First synchronous pulley; 11-9. Auxiliary rotating shaft; 11-10. Second synchronous pulley; 11-11. Third synchronous pulley; 11-12. Fourth synchronous pulley; 12. Extension tube; 12-1. Keyway; 13. Anti-rotation seat; 13-1. Guide key. Detailed Implementation

[0036] like Figure 1-9 As shown, a coalbed methane detection and sampling device includes a lower probe 1. A lower sealing bag 2 and an upper sealing bag 3 are provided at the lower end of the lower probe 1. An expansion support mechanism 6 is provided between the lower sealing bag 2 and the upper sealing bag 3. The expansion support mechanism 6 is linked to the expansion action of the upper sealing bag 3 via a connecting rod 7. Several air inlets 1-1 are provided on the lower probe 1 between the lower sealing bag 2 and the upper sealing bag 3. A filter mechanism 8 is installed on the outside of each air inlet 1-1. The lower probe 1 is connected to a blower 9 via a pipeline. The blower 9 is connected to a sampling bottle 10. A main air supply pipe 4 is provided inside the lower probe 1 for inflating the lower sealing bag 2 and the upper sealing bag 3. The main air supply pipe 4 is connected to an external air source. A lowering mechanism 11 is provided above the sampling well for placing the lower probe 1 into the sampling well.

[0037] like Figure 2-3 As shown, the lower sealing bag 2 and the upper sealing bag 3 have the same structure, and both are configured as multi-chamber bags. Taking the lower sealing bag 2 as an example, its specific structure is described. The interior of the lower sealing bag 2 is connected by two first diaphragms 2-1 along the axial direction. The two first diaphragms 2-1 divide the internal space of the lower sealing bag 2 into three annular chambers. These three annular chambers are A, B, and C axial regions from bottom to top. Each annular chamber is connected by four second diaphragms 2-2. The four second diaphragms 2-2 evenly divide the annular chamber into four sector-shaped sub-chambers, namely A1-A4, B1-B4, and C1-C4.

[0038] The main gas supply pipe 4 is connected to twelve branch gas supply pipes 5, each corresponding to a sector-shaped sub-chamber. Each branch gas supply pipe 5 is equipped with a miniature solenoid valve. Each sector-shaped sub-chamber is also equipped with a pressure sensor for real-time monitoring of the internal pressure. These branch gas supply pipes 5 pass through dedicated sealing holes on the wall of the lower probe pipe 1 and connect to the twelve sector-shaped sub-chambers respectively. Before pressurizing all sector-shaped sub-chambers, a preliminary pre-pressurization is performed on all sector-shaped sub-chambers. Based on the initial pressure feedback of each sector-shaped sub-chamber, supplementary pressurization is performed on the sector-shaped sub-chambers with lower pressure until the pressure in all sector-shaped sub-chambers is equalized.

[0039] During sealing, an "axial sequential pressurization" mode is adopted: First, pressurize the central area B1-B4 directly opposite the sampling area to the working pressure to form a core sealing zone; Second, pressurize the distal areas A1-A4 and the proximal areas C1-C4 sequentially to the working pressure to form a complete axial seal. Throughout the sampling process, the pressure of all sector sub-chambers is continuously monitored. If the pressure of a sector sub-chamber drops abnormally, for example, due to puncture by a sharp object, immediately close the solenoid valve of that sector sub-chamber to prevent gas loss; appropriately increase the pressure of the two adjacent sector sub-chambers, using the deformation of the bag material to compensate for potential seal failure in the damaged area. After sampling, slowly depressurize in the order of C area first, then A area, and finally B area to ensure safe recovery.

[0040] This invention breaks away from the traditional design of a single-chamber sealing bag as a whole cavity. Through the organic combination of the first diaphragm 2-1 and the second diaphragm 2-2, a single bag is divided into multiple independent sub-chambers evenly distributed in the axial and circumferential directions, forming a "matrix" network of sealing units. Traditional single-chamber bags fail completely once damaged. In this invention, the failure of one or even multiple sub-chambers does not lead to the collapse of the entire sealing system. Effective sealing is maintained through isolation of the faulty unit and compensation from adjacent units, achieving highly reliable operation, making it particularly suitable for harsh coal seam environments.

[0041] The lower sealing bag 2 and the upper sealing bag 3 are usually composed of three layers: (1) Outer layer: wear-resistant and anti-slip layer, usually made of high-strength, wear-resistant and tear-resistant composite material, with raised textures or patterns on the surface to increase friction and prevent displacement due to equipment vibration or wet hole wall after expansion; guide deformation and control the shape of the bag during expansion to make it more uniform; scrape mud skin, which can scrape off the soft mud skin on the well wall during expansion, allowing the rubber to directly contact the solid well wall and improve the sealing effect; (2) Middle layer: reinforced skeleton layer, which is the "skeleton" of the bag and determines its pressure bearing capacity and extrusion resistance. It adopts a cord braided layer, usually made of steel cable, Kevlar wire or high-strength polyester wire. Different layers use cords of different strengths and angles to optimize mechanical properties; (3) Airtight layer, made of highly elastic and low-permeability rubber.

[0042] A pressure-bearing pad is built into a specific position where the upper sealing bag 3 contacts the connecting rod 7 to prevent the end of the connecting rod 7 from directly piercing or excessively squeezing the soft rubber.

[0043] like Figure 4 As shown, the expansion support mechanism 6 includes a fixed mounting base 6-1 and a movable mounting base 6-2. The fixed mounting base 6-1 is fixedly connected to the lower probe tube 1, and the movable mounting base 6-2 is slidably sleeved on the lower probe tube 1. Five folding frames 6-3 are evenly distributed in a circle on the outer side of the fixed mounting base 6-1 and the movable mounting base 6-2. A support plate 6-4 is installed on the other side of the folding frame 6-3. A limiting block 6-5 is provided on the inner side of the support plate 6-4 to limit the movable end of the folding frame 6-3. The movable mounting base 6-2 is linked to the expansion action of the upper sealing bag 3 through the connecting rod 7. Specifically, the folding frame 6-3 includes two folding rods hinged together in the middle, forming an X-shaped structure. The two inner ends of the X-shaped structure are respectively hinged to the fixed mounting base 6-1 and the movable mounting base 6-2. The lower outer end of the X-shaped structure is hinged to the support plate 6-4, and the upper outer end of the X-shaped structure is slidably connected to the limiting block 6-5. The limiting block 6-5 has an elongated groove, and the mounting rod at the end of the X-shaped structure moves along the elongated groove.

[0044] When the upper sealing bag 3 expands, it will push the movable mounting base 6-2 downward through the connecting rod 7, the folding frame 6-3 unfolds, and the support plate 6-4 expands outward. The support plate 6-4 contacts the inner wall of the sampling well, supports the broken hole wall between the two sealing bags, and forms a stable sampling chamber, effectively preventing the hole from collapsing in this area and enhancing the overall sealing effect.

[0045] like Figure 5-6As shown, the filtering mechanism 8 includes an annular mounting frame 8-1, on which a filter screen 8-2 is mounted. Three connecting seats 8-3 are connected to the outer circumference of the mounting frame 8-1. The connecting seats 8-3 are connected to the outer wall of the lower probe tube 1 through a locking component assembly 8-4. A fixed seat is connected to the outer wall of the lower probe tube 1. A threaded rod 8-4-1 is rotatably mounted on the fixed seat via a pin. A U-shaped groove matching the threaded rod 8-4-1 is provided on the connecting seat 8-3. The threaded rod 8-4-1 is rotated into the U-shaped groove and locked and positioned by a locking nut 8-4-2.

[0046] When the filter needs to be cleaned or replaced, loosen the locking nut 8-4-2, rotate the threaded rod 8-4-1 away from the connecting seat 8-3, and remove the mounting frame 8-1 and the filter 8-2 together to clean or replace the filter.

[0047] like Figure 7-8 As shown, the lowering mechanism 11 includes a support frame, which includes a base frame 11-1. A vertical support 11-2 is connected to the base frame 11-1, and an inclined support 11-3 is connected to one side of the vertical support 11-2. The base frame 11-1, the vertical support 11-2, and the inclined support 11-3 form a triangular structure to improve the stability of the support frame. A rotating sleeve 11-4 is rotatably mounted on the vertical support 11-2. A driving assembly for driving the rotating sleeve 11-4 to rotate is provided on one side of the rotating sleeve 11-4. An extension tube 12 is connected to the top of the lower probe tube 1 through a flange. The extension tube 12 is threadedly connected to the rotating sleeve 11-4. The rotation of the rotating sleeve 11-4 drives the extension tube 12 to move downward.

[0048] Specifically, the drive assembly includes a first bevel gear 11-5 disposed on the outside of the rotating sleeve 11-4, a second bevel gear 11-6 meshing with the first bevel gear 11-5 mounted on the vertical support 11-2, a drive motor 11-7 mounted on the vertical support 11-2, a first synchronous pulley 11-8 mounted on the output shaft of the drive motor 11-7, an auxiliary rotating shaft 11-9 mounted on the vertical support 11-2, a second synchronous pulley 11-10 and a third synchronous pulley 11-11 mounted on the auxiliary rotating shaft 11-9, a fourth synchronous pulley 11-12 mounted on the other end of the central shaft of the second bevel gear 11-6, the first synchronous pulley 11-8 being connected to the second synchronous pulley 11-10 via a first synchronous belt, and the third synchronous pulley 11-11 being connected to the fourth synchronous pulley 11-12 via a second synchronous belt.

[0049] In use, the drive motor 11-7 is started, which drives the first synchronous pulley 11-8 to rotate. The first synchronous pulley 11-8 drives the second synchronous pulley 11-10 to rotate via the first synchronous belt. The rotation of the second synchronous pulley 11-10 drives the auxiliary shaft 11-9 to rotate. The rotation of the auxiliary shaft 11-9 drives the third synchronous pulley 11-11 to rotate. The rotation of the third synchronous pulley 11-11 drives the fourth synchronous pulley 11-12 to rotate via the second synchronous belt. The rotation of the fourth synchronous pulley 11-12 drives the second bevel gear 11-6 to rotate. The rotation of the second bevel gear 11-6 drives the first bevel gear 11-5 to rotate. The rotation of the first bevel gear 11-5 drives the rotating sleeve 11-4 to rotate. Since the rotating sleeve 11-4 is threadedly connected to the extension tube 12, the rotational motion of the rotating sleeve 11-4 is converted into the vertical movement of the extension tube 12.

[0050] To prevent the extended tube 12 from rotating together with the rotating sleeve 11-4, an anti-rotation seat 13 is installed on the support frame, such as... Figure 9 As shown, a guide key 13-1 is installed on the anti-rotation seat 13, and a keyway 12-1 matching the guide key 13-1 is opened on the extension tube 12. The diameter of the through hole of the anti-rotation seat 13 is larger than the outer diameter of the extension tube 12.

[0051] The working process of this invention is as follows:

[0052] First, the lower probe 1 is installed at the bottom end of the extension tube 12. Then, the drive assembly drives the rotating sleeve 11-4 to rotate, thereby moving the extension tube 12 and the lower probe 1 downwards, so that the lower probe 1 extends into the sampling well. When it descends to the sampling depth, high-pressure gas is filled into the lower sealing bag 2 using the main gas supply pipe 4, causing the lower sealing bag 2 to expand first and seal the distal end. Then, gas is filled into the upper sealing bag 3 to seal the proximal end. During the expansion of the upper sealing bag 3, the support plate 6-4 expands outwards. The support plate 6-4 contacts the inner wall of the sampling well and supports the broken hole wall between the two sealing bags, forming a stable sampling chamber. Finally, the exhaust fan 9 is started to extract coalbed methane and discharge it into the sampling bottle 10, completing the coal seam sampling.

[0053] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A coalbed methane detection and sampling device, characterized in that: The device includes a lower probe (1), with a lower sealing bag (2) and an upper sealing bag (3) at its lower end. An expansion support mechanism (6) is provided between the lower sealing bag (2) and the upper sealing bag (3). The expansion support mechanism (6) is linked to the expansion action of the upper sealing bag (3) via a connecting rod (7). Several air inlets (1-1) are provided on the lower probe (1) and between the lower sealing bag (2) and the upper sealing bag (3). A filter mechanism (8) is provided on the outside of the air inlet (1-1). The lower probe (1) is connected to the exhaust fan (9) through a pipeline. The exhaust fan (9) is connected to the sampling bottle (10). The lower probe (1) is provided with a main air supply pipe (4) for inflating the lower sealing bag (2) and the upper sealing bag (3). The main air supply pipe (4) is connected to an external air source. A lowering mechanism (11) for placing the lower probe (1) into the sampling well is provided above the sampling well.

2. The coalbed methane detection and sampling device according to claim 1, characterized in that: The lower sealing bag (2) and the upper sealing bag (3) have the same structure, and both the lower sealing bag (2) and the upper sealing bag (3) are configured as multi-chamber bags.

3. The coalbed methane detection and sampling device according to claim 2, characterized in that: The lower sealing bag (2) has a plurality of first diaphragms (2-1) arranged axially inside. The plurality of first diaphragms (2-1) divide the internal space of the lower sealing bag (2) into a plurality of annular chambers. Each annular chamber is provided with a plurality of second diaphragms (2-2), and the plurality of second diaphragms (2-2) divide the annular chamber into a plurality of fan-shaped sub-chambers.

4. The coalbed methane detection and sampling device according to claim 3, characterized in that: The main gas supply pipe (4) is provided with several branch gas supply pipes (5), and each branch gas supply pipe (5) corresponds to one of the fan-shaped sub-chambers. Each branch gas supply pipe (5) is provided with a miniature solenoid valve.

5. The coalbed methane detection and sampling device according to claim 1, characterized in that: The expansion support mechanism (6) includes a fixed mounting base (6-1) and a movable mounting base (6-2). The fixed mounting base (6-1) is fixedly mounted on the lower probe (1), and the movable mounting base (6-2) is slidably mounted on the lower probe (1). Several folding frames (6-3) are evenly distributed in a circle on the outer side of the fixed mounting base (6-1) and the movable mounting base (6-2). A support plate (6-4) is provided on the other side of the folding frame (6-3). A limiting block (6-5) for limiting the movable end of the folding frame (6-3) is provided on the inner side of the support plate (6-4). The movable mounting base (6-2) is linked to the expansion action of the upper sealing bag (3) through the connecting rod (7).

6. The coalbed methane detection and sampling device according to claim 5, characterized in that: The folding frame (6-3) includes two folding rods hinged together in the middle, forming an X-shaped structure. The two ends of the inner side of the X-shaped structure are respectively hinged to the fixed mounting base (6-1) and the movable mounting base (6-2). The lower end of the outer side of the X-shaped structure is hinged to the support plate (6-4), and the upper end of the outer side of the X-shaped structure is slidably connected to the limiting block (6-5).

7. The coalbed methane detection and sampling device according to claim 1, characterized in that: The filtering mechanism (8) includes an annular mounting frame (8-1), on which a filter screen (8-2) is provided. Several connecting seats (8-3) are provided on the outer circumference of the mounting frame (8-1), and the connecting seats (8-3) are connected to the outer wall of the lower probe (1) through a locking component assembly (8-4). A fixed seat is provided on the outer wall of the lower probe (1). A threaded rod (8-4-1) is rotatably provided on the fixed seat via a pin. A U-shaped groove matching the threaded rod (8-4-1) is provided on the connecting seat (8-3). The threaded rod (8-4-1) is rotated into the U-shaped groove and locked and positioned by a locking nut (8-4-2).

8. The coalbed methane detection and sampling device according to claim 1, characterized in that: The lowering mechanism (11) includes a support frame, on which a rotating sleeve (11-4) is provided. A driving component for driving the rotating sleeve (11-4) to rotate is provided on one side of the rotating sleeve (11-4). An extension tube (12) is provided at the top of the lower probe (1). The extension tube (12) is threadedly connected to the rotating sleeve (11-4). The rotation of the rotating sleeve (11-4) drives the extension tube (12) to move downward.

9. The coalbed methane detection and sampling device according to claim 8, characterized in that: The drive assembly includes a first bevel gear (11-5) disposed on the outside of the rotating sleeve (11-4), a second bevel gear (11-6) meshing with the first bevel gear (11-5) disposed on the support frame, a drive motor (11-7) disposed on the support frame, a first synchronous pulley (11-8) disposed on the output shaft of the drive motor (11-7), an auxiliary rotating shaft (11-9) disposed on the support frame, a second synchronous pulley (11-10) and a third synchronous pulley (11-11) disposed on the auxiliary rotating shaft (11-9), a fourth synchronous pulley (11-12) disposed at the other end of the central shaft of the second bevel gear (11-6), the first synchronous pulley (11-8) being connected to the second synchronous pulley (11-10) via a first synchronous belt, and the third synchronous pulley (11-11) being connected to the fourth synchronous pulley (11-12) via a second synchronous belt.

10. The coalbed methane detection and sampling device according to claim 8, characterized in that: The support frame is provided with an anti-rotation seat (13), the anti-rotation seat (13) is provided with a guide key (13-1), the extension tube (12) is provided with a keyway (12-1) that matches the guide key (13-1), and the diameter of the through hole of the anti-rotation seat (13) is larger than the outer diameter of the extension tube (12).

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