Multi-stage extraction and outburst elimination device and method for cross-cut coal uncovering

Abstract

The application discloses a multi-stage extraction outburst elimination device and method for cross-cut coal uncovering. The multi-stage extraction outburst elimination device for cross-cut coal uncovering comprises a central shaft, a drilling pressure relief device, a stress diffusion device, a connecting assembly and a deep removal device. The drilling pressure relief device is fixed at the front end of the central shaft. The stress diffusion device is fixed on the central shaft and fixedly connected with the drilling pressure relief device. The connecting assembly is slidably arranged on the central shaft and rotationally connected with the end of the stress diffusion device away from the drilling pressure relief device. The deep removal device is fixedly connected with one end of the connecting assembly and slidably connected with the other end of the connecting assembly. The application utilizes vibration load to destroy the coal body adsorption balance, completely removes the deep residual gas, realizes the depth coupling of multi-stage extraction and stress release, and finally eliminates the coal seam outburst danger.

Description

Technical Field

[0001] This invention belongs to the field of coal mine gas control technology, and specifically provides a multi-stage extraction and gas outburst suppression device and method for coal seam exposure in rock passages. Background Technology

[0002] In coal seam exposure operations in rock face, coal seam gas outbursts pose a significant safety hazard. Traditional single-stage extraction methods are insufficient to efficiently release coal seam stress and completely eliminate the outburst risk. Existing technologies typically employ direct borehole extraction of gas. However, even after the release of shallow high-pressure gas, the deep coal seam still poses an outburst risk due to stress concentration and adsorbed gas residue. Furthermore, coal dust easily clogs the extraction channels during the extraction process, leading to reduced extraction efficiency. Simultaneously, the pressure relief range of a single borehole is limited, failing to create an effective stress release structure. Therefore, multi-stage coordinated processing is necessary to achieve deep pressure relief of the coal seam and complete gas extraction. Thus, it is essential to provide a multi-stage extraction and outburst mitigation device and method for rock face coal seam exposure to address the problems mentioned in the background. Summary of the Invention

[0003] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a multi-stage extraction and outburst elimination device for coal seam exposure in a rock gate, including a central shaft, a drilling and pressure relief device, a stress diffusion device, a connecting component and a deep cleaning device. The central shaft is driven by an external driving device, and its outer wall is provided with multiple sets of connecting holes, and the interior is an extraction channel.

[0004] The drilling pressure relief device is fixed at the front end of the central shaft, the stress diffusion device is fixed on the central shaft and is fixedly connected to the drilling pressure relief device, the connecting component is slidably disposed on the central shaft and is rotatably connected to the end of the stress diffusion device away from the drilling pressure relief device, one end of the deep cleaning device is fixedly connected to the connecting component and the other end is slidably connected to the connecting component.

[0005] Furthermore, the drilling pressure relief device includes a spiral drill bit, a pressure relief ring body, and a protective mesh surface. The spiral drill bit is fixed to the front end of the central shaft, the pressure relief ring body is fixed on the central shaft, the inner ring of the pressure relief ring body is connected to the connecting hole on the central shaft, and a extraction ring is provided on the side of the spiral drill bit. The protective mesh surface is fixed on the extraction ring on the side of the pressure relief ring body.

[0006] Furthermore, the stress diffusion device includes a connecting seat, a cutting assembly, a movable seat, a telescopic column, and connecting rods. The connecting seat is fixed on the central shaft and is fixedly connected to the drilling pressure relief device. Multiple cutting assemblies are arranged in a ring, and one end of the cutting assembly is rotatably connected to the connecting seat. The movable seat is movably mounted on the central shaft and is rotatably connected to the connecting assembly. The telescopic column is sleeved on the central shaft, and its two ends are respectively connected to the movable seat and the connecting seat. Multiple connecting rods are arranged in a ring, one end of which is rotatably connected to the inner side of the cutting assembly, and the other end is rotatably connected to the movable seat.

[0007] Furthermore, the cutting assembly includes an adjusting plate and drill teeth. One end of the adjusting plate is rotatably connected to a connecting seat, and its inner side is rotatably connected to a connecting rod. The drill teeth are arranged in a trapezoidal shape and are fixedly assembled on the outer side of the adjusting plate.

[0008] Furthermore, the connecting assembly includes a connecting ring, an extraction ring body, and a central shaft. The connecting ring is rotatably connected to the movable seat, the extraction ring body is fixed at the end of the connecting ring away from the movable seat, and the central shaft body is slidably disposed on the central shaft and fixedly connected to the extraction ring body.

[0009] Furthermore, the inner wall of the extraction ring is provided with a connecting ring corresponding to the connecting hole on the central axis, and the outer wall is provided with multiple sets of linearly distributed extraction holes, with each set of extraction holes arranged in a ring.

[0010] Furthermore, the deep cleaning device includes guide columns, a moving assembly, a vibrating plate, and a vibration groove. Multiple guide columns are arranged in a ring and fixed on a connecting ring. The guide columns are spaced apart from the cutting assembly. The moving assembly is movably mounted on the connecting assembly. The vibrating plate is arranged corresponding to the inclined surfaces of the guide columns, and one end of the vibrating plate is fixed to the moving assembly. Multiple vibration grooves are arranged in a ring and fixed on the side wall of the moving assembly away from the guide columns. A vibration motor is installed inside the vibration groove.

[0011] Furthermore, the movable component includes a movable column, a rotating shaft, and a fixed ring. The movable column is movably mounted on the connecting component, and its sidewall is fixedly connected to the vibration groove. Multiple rotating shafts are arranged in a ring and are rotatably mounted on the sidewall of the movable column. The rotating shaft is located at the end away from the vibration groove. The rotating shaft is fixedly connected to the vibration plate. The fixed ring is threadedly connected to the outer wall of the movable component. The end opposite to the movable column is attached to the movable column through a shock-absorbing material.

[0012] A multi-stage extraction and outburst mitigation method for coal seam exposure in stone gates, characterized by the following steps:

[0013] Step 1: Determine the borehole location, drive the central shaft to drive the drilling pressure relief device and stress diffusion device to drill into the coal seam. When the auger bit cuts into the coal seam and the pressure relief ring enters the borehole, the shallow high-pressure gas enters the pressure relief ring through the protective mesh. Under pressure impact, the gas enters the extraction channel inside the central shaft through the extraction ring of the pressure relief ring, and the high-pressure gas is discharged.

[0014] Step 2: After the central shaft drives the drilling pressure relief device into the coal seam, the high-pressure gas is continuously discharged. When the gas pressure drops below 0.5MPa, the discharge is stopped and the extraction channel is sealed to prevent air backflow and explosion. Then, while the central shaft drives the drilling pressure relief device and stress diffusion device to rotate, the connecting component pushes the moving seat to move towards the connecting seat, compressing the telescopic column. Then, through the connecting rod, the cutting component is pushed to rotate and unfold on the connecting seat, so that the cutting component unfolds to a 90-degree angle to cut the coal seam. Then, driven by the central shaft, the cutting component cuts the coal body to form an annular stress relief groove with a depth of 0.5m, which promotes the development of coal seam pores and fractures.

[0015] Step 3: As the stress relief groove is formed, the central shaft stops rotating. The extraction ring body remains connected to the connecting hole on the central shaft. Then, the gas in the coal seam is extracted and discharged through the pressure relief ring body and the extraction ring body together, and discharged through the extraction channel inside the central shaft.

[0016] Step 4: While performing secondary extraction, the moving column pushes the vibrating plate towards the cutting components. Guided by the inclined surface on the guide column, the vibrating plate rotates on the moving column via the rotating shaft, expanding outwards and contacting the coal seam. Under the action of the vibrating motor, the vibrating plate vibrates, promoting the desorption of adsorbed gas in the coal seam and further promoting the development of coal seam pores and fractures. The coal seam gas is continuously extracted through the pressure relief ring and extraction ring until the residual gas pressure in the coal body drops to a safe range.

[0017] The beneficial effects of using this invention are:

[0018] In this invention, the rapid discharge of shallow high-pressure gas and the filtration of coal powder are achieved through the coordinated arrangement of the auger drill bit and the pressure relief ring in the drilling pressure relief device, preventing blockage of the extraction channel and ensuring that the gas pressure continues to decrease to a safe threshold.

[0019] Through the linkage design of the cutting component and the telescopic column in the stress diffusion device, an annular stress relief groove is formed inside the coal seam, which expands the pressure relief range and promotes the development of coal body fractures, thereby improving the gas desorption efficiency.

[0020] The sliding connection structure between the connecting component and the extraction ring allows the cutting operation to be carried out simultaneously with the gas extraction, keeping the extraction channel unobstructed.

[0021] By combining the vibrating plate and the guide column in the deep removal device, the adsorption balance of the coal body is disrupted by the vibration load, the residual gas in the deep is completely removed, and the deep coupling of multi-stage extraction and stress release is achieved, ultimately eliminating the risk of coal seam outburst. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the device structure of the present invention;

[0023] Figure 2 This is a schematic diagram of the drilling pressure relief device and stress diffusion device of the present invention;

[0024] Figure 3 This is a schematic diagram of the cutting component structure of the present invention;

[0025] Figure 4 This is a schematic diagram of the connecting assembly and deep cleaning device of the present invention;

[0026] Figure 5 This is a schematic diagram of the mobile component structure of the present invention;

[0027] Figure 6 This is a schematic diagram of the stress diffusion device of the present invention.

[0028] Figure 7 This is a schematic diagram of the deep cleaning device of the present invention.

[0029] The reference numerals in the figures include:

[0030] 1. Central axis;

[0031] 2. Drilling pressure relief device; 21. Auger bit; 22. Pressure relief ring; 23. Protective mesh surface;

[0032] 3. Stress diffusion device; 31. Connecting seat; 32. Cutting assembly; 321. Adjusting plate; 322. Drill teeth; 33. Moving seat; 34. Telescopic column; 35. Connecting rod;

[0033] 4. Connecting components; 41. Connecting ring; 42. Extraction ring body; 43. Central shaft body;

[0034] 5. Deep cleaning device; 51. Guide column; 52. Moving component; 53. Vibrating plate; 54. Vibration groove; 521. Moving column; 522. Rotating shaft; 523. Fixing ring. Detailed Implementation

[0035] The present invention will now be described in detail with reference to the accompanying drawings.

[0036] Reference Figures 1-7 A multi-stage extraction and outburst elimination device for coal seam exposure in a rock face includes a central shaft 1, which is driven by an external drive device and has multiple sets of connecting holes on its outer wall, with an extraction channel inside.

[0037] Drilling in the pressure relief device 2, which is fixed at the front end of the central shaft 1;

[0038] Stress diffusion device 3 is fixed on central shaft 1 and fixedly connected to drilling pressure relief device 2;

[0039] The connecting component 4 is slidably mounted on the central shaft 1 and rotatably connected to the end of the stress diffusion device 3 away from the drilling pressure relief device 2.

[0040] The deep cleaning device 5 is fixedly connected to the connecting component 4 at one end and slidably connected to the connecting component 4 at the other end.

[0041] Specifically, the drilling pressure relief device 2 includes:

[0042] The auger drill bit 21 is fixed at the front end of the central shaft 1;

[0043] The pressure relief ring 22 is fixed on the central shaft 1 and connects the auger drill bit 21 and the stress diffusion device 3. The inner ring of the pressure relief ring 22 is connected to the connecting hole on the central shaft 1, and a extraction ring is provided on the side near the auger drill bit 21.

[0044] The protective netting 23 is fixed to the side extraction ring of the pressure relief ring 22.

[0045] When the central shaft 1 drives the auger bit 21 to drill into the coal seam, as the auger bit 21 cuts into the coal seam and the pressure relief ring 22 enters the borehole, shallow high-pressure gas (usually >1.5MPa) enters the pressure relief ring 22 through the protective mesh 23. Under pressure impact, the gas enters the extraction channel inside the central shaft 1 through the extraction ring of the pressure relief ring 22, discharging the high-pressure gas. Under high pressure, some coal dust can also be discharged along with the gas, while coal chunks are blocked by the protective mesh 23, effectively preventing blockage of the extraction channel. The gas continues to be discharged through the extraction channel until the gas pressure drops below 0.5MPa, at which point extraction stops and the extraction channel is sealed to prevent air backflow and potential explosion.

[0046] Specifically, the stress diffusion device 3 includes:

[0047] The connecting seat 31 is fixed on the central shaft 1 and is fixedly connected to the drilling pressure relief device 2;

[0048] The cutting components 32 are arranged in a ring, and one end is rotatably connected to the connecting seat 31.

[0049] The movable seat 33 is movably mounted on the central shaft 1 and rotatably connected to the connecting assembly 4;

[0050] The telescopic column 34 is sleeved on the central shaft 1, and its two ends are respectively connected to the movable seat 33 and the connecting seat 31;

[0051] Multiple connecting rods 35 are arranged in a ring, one end of which is rotatably connected to the inner side of the cutting assembly 32, and the other end is rotatably connected to the movable seat 33.

[0052] When the internal gas pressure of the coal seam drops below 0.5 MPa, while the central shaft 1 drives the drilling pressure relief device 2 and stress diffusion device 3 to rotate, the connecting component 4 pushes the moving seat 33 to move towards the connecting seat 31, compressing the telescopic column 34. Then, through the connecting rod 35, the cutting component 32 is pushed to rotate and unfold on the connecting seat 31, so that the cutting component 32 unfolds to a 90-degree angle to cut the coal seam. The maximum opening and closing angle of the cutting component 32 is 120 degrees. Then, driven by the central shaft 1, the cutting component 32 cuts the coal body, forming an annular stress relief groove with a depth of 0.5 m, promoting the development of coal seam pores and fractures.

[0053] Furthermore, the cutting assembly 32 includes an adjustment plate 321 and drill teeth 322.

[0054] The adjusting plate 321 is rotatably connected to the connecting seat 31 at one end and rotatably connected to the connecting rod 35 on the inner side.

[0055] The drill teeth 322 are arranged in a trapezoidal shape and are fixed on the outside of the adjustment plate 321.

[0056] Driven by the central shaft 1, the connecting seat 31 drives the cutting assembly 32 to rotate, and then cuts the coal seam by adjusting the drill teeth 322 on the plate surface 321. Under the pushing action of the connecting assembly 4, the moving seat 33 moves towards the connecting seat 31, and pushes the adjusting plate surface 321 to open through the connecting rod 35, so that the drill teeth 322 move to the designated position. During the cutting process, an annular stress relief groove is formed, which further promotes the desorption of gas.

[0057] Specifically, the connecting assembly 4 includes a connecting ring 41, an extraction ring body 42, and a central shaft 43.

[0058] The connecting ring 41 is rotatably connected to the movable seat 33;

[0059] The extraction ring 42 is fixed to the end of the connecting ring 41 away from the movable seat 33;

[0060] The central shaft 43 is slidably mounted on the central shaft 1 and is fixedly connected to the extraction ring 42.

[0061] The inner wall of the extraction ring 42 is provided with a connecting ring corresponding to the connecting hole on the central axis 1, and the outer wall is provided with multiple sets of linearly distributed extraction holes, with each set of extraction holes arranged in a ring.

[0062] By pushing the central shaft 43 to slide on the central shaft 1, the extraction ring 42 and the connecting ring 41 are driven to move the moving seat 33 toward the connecting seat 31, thereby adjusting the unfolding angle of the cutting assembly 32. While adjusting the unfolding angle of the cutting assembly 32, the connecting ring on the inner wall of the extraction ring 42 is connected to the connecting hole on the central shaft 1. Furthermore, when adjusting the unfolding angle of the cutting assembly 32, the connecting ring on the inner wall of the extraction ring 42 is always connected to the connecting hole on the central shaft 1, thus cutting the coal seam at any angle. The extraction ring 42 can extract gas. It should be noted that after cutting out the stress relief groove, the central shaft 1 stops rotating. The gas in the coal seam is extracted by the pressure relief ring 22 and the extraction ring 42 together, and the stress diffusion device 3 stops at the position corresponding to the initial state and the deep removal device 5.

[0063] The deep cleaning device 5 includes a guide column 51, a moving assembly 52, a vibrating plate 53, and a vibrating groove 54.

[0064] Multiple guide posts 51 are arranged in a ring and fixed on the connecting ring 41, and the guide posts 51 are spaced apart from the cutting assembly 32.

[0065] The movable component 52 is moved onto the connecting component 4;

[0066] The vibrating plate 53 is set corresponding to the inclined surface of the guide column 51, and one end is fixed to the moving component 52.

[0067] Multiple vibration grooves 54 are arranged in a ring and fixed on the side wall of the moving component 52 away from the guide column 51. A vibration motor is installed inside the vibration groove 54.

[0068] While the coal seam gas is being pumped out for the second time, the moving component 52 drives the vibrating plate 53 to move between the cutting component 32. Under the guidance of the inclined surface on the guide column 51, the vibrating plate 53 rotates on the moving component 52, expands outward, and comes into contact with the coal seam. Under the action of the vibration motor, the vibrating plate 53 vibrates, which promotes the desorption of adsorbed gas in the coal seam and further promotes the development of coal seam pores and fractures. In addition, multiple diaphragms are arranged sequentially on the vibrating plate 53. Under the coupling action of gas pressure and vibration load, the diaphragms form a periodic opening and closing action, with an opening and closing frequency of up to 120 times per minute, which completely removes adsorbed gas.

[0069] Furthermore, the moving component 52 includes: a moving column 521, a rotating shaft 522, and a retaining ring 523.

[0070] The movable column 521 is movably mounted on the connecting assembly 4, and its sidewall is fixedly connected to the vibration groove 54.

[0071] Multiple rotating shafts 522 are arranged in a ring and are rotatably mounted on the side wall of the movable column 521, located at the end away from the vibration groove 54. The rotating shafts 522 are fixedly connected to the vibration plate 53.

[0072] The retaining ring 523 is threaded to the outer wall of the moving component 52, and the end opposite to the moving column 521 is attached to the moving column 521 through a shock-absorbing material.

[0073] While the coal seam gas is being pumped out for the second time, the moving column 521 pushes the vibrating plate 53 to move between the cutting components 32. Under the guidance of the inclined surface on the guide column 51, the vibrating plate 53 rotates on the moving column 521 through the rotating shaft 522, expands outward, and comes into contact with the coal seam. Under the action of the vibration motor, the vibrating plate 53 is driven to vibrate. The vibration promotes the desorption of adsorbed gas in the coal seam and further promotes the development of coal seam pores and fractures.

[0074] A method for multi-stage extraction and outburst mitigation in coal seam exposure at rock gates, characterized by the following steps:

[0075] Step 1: Determine the borehole location, drive the central shaft 1 to drive the drilling pressure relief device 2 and stress diffusion device 3 to drill into the coal seam. When the auger bit 21 cuts into the coal seam and the pressure relief ring 22 enters the borehole, the shallow high-pressure gas (usually >1.5MPa) enters the pressure relief ring 22 through the protective mesh 23. Under pressure impact, the gas enters the extraction channel inside the central shaft 1 through the extraction ring of the pressure relief ring 22, and the high-pressure gas is discharged.

[0076] Step 2: After the central shaft 1 drives the drilling pressure relief device 2 into the coal seam, the high-pressure gas is continuously discharged. When the gas pressure drops below 0.5MPa, the discharge is stopped and the extraction channel is sealed to prevent air backflow and explosion. Then, while the central shaft 1 drives the drilling pressure relief device 2 and stress diffusion device 3 to rotate, the connecting component 4 pushes the moving seat 33 to move towards the connecting seat 31, compressing the telescopic column 34. Then, through the connecting rod 35, the cutting component 32 is pushed to rotate and unfold on the connecting seat 31, so that the cutting component 32 unfolds to a 90-degree angle to cut the coal seam. Then, driven by the central shaft 1, the cutting component 32 cuts the coal body to form an annular stress relief groove with a depth of 0.5m, which promotes the development of coal seam pores and cracks.

[0077] Step 3: As the stress relief groove is formed, the central shaft 1 stops rotating, and the extraction ring 42 remains connected to the connecting hole on the central shaft 1. Then, the gas in the coal seam is extracted and discharged through the pressure relief ring 22 and the extraction ring 42 together, and discharged through the extraction channel inside the central shaft 1.

[0078] Step 4: While performing secondary extraction, the moving column 521 pushes the vibrating plate 53 to move between the cutting components 32. Guided by the inclined surface on the guide column 51, the vibrating plate 53 rotates on the moving column 521 via the rotating shaft 522, expanding outward and contacting the coal seam. Under the action of the vibrating motor, the vibrating plate 53 vibrates, which promotes the desorption of adsorbed gas in the coal seam and further promotes the development of coal seam pores and fractures. The gas is continuously extracted from the coal seam through the pressure relief ring 22 and the extraction ring 42 until the residual gas pressure in the coal body drops to a safe range (at least below 0.3 MPa).

[0079] The above content is only a preferred embodiment of the present invention. For those skilled in the art, many changes can be made in the specific implementation and application scope based on the concept of the present invention. As long as these changes do not depart from the concept of the present invention, they all fall within the protection scope of the present invention.

Claims

1. A multi-stage extraction and outburst mitigation device for coal seam exposure in a rock face, characterized in that: It includes a central shaft, a drilling pressure relief device, a stress diffusion device, a connecting assembly, and a deep cleaning device. The central shaft is driven by an external drive device, and its outer wall is provided with multiple sets of connecting holes, while the interior is a extraction channel. The drilling pressure relief device is fixed at the front end of the central shaft, the stress diffusion device is fixed on the central shaft, and the stress diffusion device is fixedly connected to the drilling pressure relief device. The connecting component is slidably arranged on the central shaft, and the connecting component is rotatably connected to the end of the stress diffusion device away from the drilling pressure relief device. The connecting assembly includes a connecting ring, an extraction ring body, and a central shaft. The connecting ring is rotatably connected to the movable seat. The extraction ring body is fixed at the end of the connecting ring away from the movable seat. The central shaft body is slidably mounted on the central shaft and is fixedly connected to the extraction ring body. The stress diffusion device includes a connecting seat, a cutting assembly, a movable seat, a telescopic column, and connecting rods. The connecting seat is fixed on the central shaft and is fixedly connected to the drilling pressure relief device. Multiple cutting assemblies are arranged in a ring, and one end of the cutting assembly is rotatably connected to the connecting seat. The movable seat is movably mounted on the central shaft and is rotatably connected to the connecting assembly. The telescopic column is sleeved on the central shaft, and its two ends are respectively connected to the movable seat and the connecting seat. Multiple connecting rods are arranged in a ring, one end of which is rotatably connected to the inner side of the cutting assembly, and the other end is rotatably connected to the movable seat. The deep cleaning device includes guide columns, a moving assembly, a vibrating plate, and a vibration groove. Multiple guide columns are arranged in a ring and fixed on a connecting ring. The guide columns are spaced apart from the cutting assembly. The moving assembly is movably mounted on the connecting assembly. The vibrating plate is arranged with the inclined surfaces of the guide columns corresponding to each other, and one end of the vibrating plate is fixed to the moving assembly. Multiple vibration grooves are arranged in a ring and fixed on the side wall of the moving assembly away from the guide columns. A vibration motor is installed inside the vibration groove.

2. The multi-stage extraction and outburst mitigation device for coal seam exposure in a rock face as described in claim 1, characterized in that: The drilling pressure relief device includes a spiral drill bit, a pressure relief ring body, and a protective mesh surface. The spiral drill bit is fixed to the front end of the central shaft, the pressure relief ring body is fixed on the central shaft, the inner ring of the pressure relief ring body is connected to the connecting hole on the central shaft, and a extraction ring is provided on the side of the spiral drill bit. The protective mesh surface is fixed on the extraction ring on the side of the pressure relief ring body.

3. The multi-stage extraction and outburst mitigation device for coal seam exposure in a rock face as described in claim 1, characterized in that: The cutting assembly includes an adjusting plate and drill teeth. One end of the adjusting plate is rotatably connected to a connecting seat, and its inner side is rotatably connected to a connecting rod. The drill teeth are arranged in a trapezoidal shape and are fixedly assembled on the outer side of the adjusting plate.

4. The multi-stage extraction and outburst mitigation device for coal seam exposure in a rock face as described in claim 1, characterized in that: The inner wall of the extraction ring is provided with a connecting ring corresponding to the connecting hole on the central axis, and the outer wall is provided with multiple sets of linearly distributed extraction holes, with each set of extraction holes arranged in a ring.

5. A multi-stage extraction and outburst mitigation device for coal seam exposure in a rock face as described in claim 1, characterized in that: The movable component includes a movable column, a rotating shaft, and a fixed ring. The movable column is movably mounted on the connecting component, and its sidewall is fixedly connected to the vibration groove. Multiple rotating shafts are arranged in a ring and are rotatably mounted on the sidewall of the movable column. The rotating shaft is located at the end away from the vibration groove. The rotating shaft is fixedly connected to the vibration plate. The fixed ring is threadedly connected to the outer wall of the movable component. The end opposite to the movable column is attached to the movable column through a shock-absorbing material.

6. A method for multi-stage drainage and outburst mitigation in coal seam exposure at rock face, employing the multi-stage drainage and outburst mitigation device for coal seam exposure at rock face as described in any one of claims 1-5, characterized in that: Includes the following steps: Step 1: Determine the borehole location, drive the central shaft to drive the drilling pressure relief device and stress diffusion device to drill into the coal seam. When the auger bit cuts into the coal seam and the pressure relief ring enters the borehole, the shallow high-pressure gas enters the pressure relief ring through the protective mesh. Under pressure impact, the gas enters the extraction channel inside the central shaft through the extraction ring of the pressure relief ring, and the high-pressure gas is discharged. Step 2: After the central shaft drives the drilling pressure relief device into the coal seam, the high-pressure gas is continuously discharged. When the gas pressure drops below 0.5MPa, the discharge is stopped and the extraction channel is sealed to prevent air backflow and explosion. Then, while the central shaft drives the drilling pressure relief device and stress diffusion device to rotate, the connecting component pushes the moving seat to move towards the connecting seat, compressing the telescopic column. Then, through the connecting rod, the cutting component is pushed to rotate and unfold on the connecting seat, so that the cutting component unfolds to a 90-degree angle to cut the coal seam. Then, driven by the central shaft, the cutting component cuts the coal body to form an annular stress relief groove with a depth of 0.5m, which promotes the development of coal seam pores and fractures. Step 3: As the stress relief groove is formed, the central shaft stops rotating. The extraction ring body remains connected to the connecting hole on the central shaft. Then, the gas in the coal seam is extracted and discharged through the pressure relief ring body and the extraction ring body together, and discharged through the extraction channel inside the central shaft. Step 4: While performing secondary extraction, the moving column pushes the vibrating plate towards the cutting components. Guided by the inclined surface on the guide column, the vibrating plate rotates on the moving column via the rotating shaft, expanding outwards and contacting the coal seam. Under the action of the vibrating motor, the vibrating plate vibrates, promoting the desorption of adsorbed gas in the coal seam and further promoting the development of coal seam pores and fractures. The coal seam gas is continuously extracted through the pressure relief ring and extraction ring until the residual gas pressure in the coal body drops to a safe range.

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