A secondary hole cleaning and unblocking device and method for delayed sealing of coal seam boreholes

Abstract

This invention discloses a secondary borehole cleaning and unblocking device and method specifically for delayed sealing of coal seam boreholes. The device consists of two main units: a support unit and a slag removal unit. The slag removal unit includes a drill bit, a hollow spiral auger, a drive shaft, a control box, and a mobile trolley. The drill bit is fixed to the front end of the auger, and the rear end of the auger is connected to the drive shaft and driven by it. The drive shaft is mounted in the control box, and the control box is fixed to the mobile trolley. The support unit is a split-type assembly structure, with three sections arranged sequentially along the feed direction: steering, orientation adjustment, and angle adjustment. The angle adjustment section has a hollow guide channel, and the bottom support leg adjusts the auger's inclination angle to match the borehole. The orientation adjustment section has an internally threaded hollow feed channel that meshes with the auger's threaded blades to control forward and backward movement, and the bottom support leg adjusts the height. The steering section has a curved hollow channel that guides the auger from the axial direction to the radial direction in the roadway, with a support leg at the front end and a telescopic hose at the rear. This invention solves the problems of poor adaptability, poor borehole cleaning effect, and difficult transportation of existing borehole cleaning equipment.

Description

Technical Field

[0001] This invention relates to the field of secondary hole cleaning technology for underground coal mines, and particularly to a special secondary hole cleaning and unblocking device and method for delayed sealing of coal seam boreholes. Background Technology

[0002] In underground coal mine drilling projects for gas extraction and water exploration, the conventional construction process involves sealing the borehole immediately after drilling to ensure the smooth progress of subsequent extraction and exploration operations. However, under complex underground conditions, due to factors such as the connection between construction procedures, on-site equipment allocation, and interference from cross-operations, most boreholes cannot be sealed immediately after drilling, leaving them in an open, idle state for extended periods. This poses a significant risk of borehole blockage and wall collapse. Underground roadways and coal seams are constantly under dynamic mining stress. After drilling, the original stress balance of the surrounding rock is disrupted. In the open-bore state, the coal and rock mass in the borehole wall is prone to loosening, crumbling, and spalling, leading to a large accumulation of coal slag and rock debris inside the sealed section of the borehole. Especially for soft coal, the coal body itself has low strength, well-developed fractures, and extremely poor self-stabilizing ability. Under mining-induced stress disturbances, it is prone to plastic deformation, borehole collapse, and diameter reduction, making the borehole sealing section more susceptible to blockage. Simultaneously, factors such as underground water seepage, dust accumulation, and compression deformation due to micro-fractures in the surrounding rock further exacerbate the blockage and diameter reduction problems in the sealing section, preventing subsequent sealing equipment and pipelines from being properly lowered into the borehole. This severely impacts the sealing construction progress and sealing quality, easily leading to gas extraction leaks, distorted water exploration data, and other engineering defects, creating potential mine safety hazards. Currently, there is no dedicated small-scale, portable secondary borehole cleaning equipment to address the aforementioned borehole blockage problem, and existing methods have significant drawbacks. Traditional solutions require the relocation and repositioning of large drilling rigs for secondary borehole cleaning and slag removal. However, the relocation, alignment, and debugging of drilling rigs are cumbersome, time-consuming, and labor-intensive, severely reducing construction efficiency, delaying project progress, and significantly increasing construction costs. In some cases, manual tamping with sealing pipes is used for hole cleaning at the site. However, the sealing pipes lack rigidity and have limited impact force, only able to clear loose debris in the shallow layer at the hole opening. They cannot break up the compacted rock debris and blockages in the sealed section, resulting in extremely poor hole cleaning effect and difficulty in completely clearing the borehole, failing to meet the requirements of standardized hole sealing construction. In summary, the existing hole cleaning methods have poor adaptability, low efficiency, and incomplete hole cleaning, failing to meet the needs of secondary hole cleaning operations after delayed hole sealing in underground drilling. In particular, they are unable to cope with the severe hole blockage problem in the sealed section of soft coal seam drilling, seriously restricting the quality and efficiency of underground drilling construction. Summary of the Invention

[0003] In view of the problems existing in the prior art, the present invention aims to provide a special secondary hole cleaning and unblocking device and method for delayed sealing of coal seam boreholes, so as to solve the problems of poor adaptability, poor hole cleaning effect and difficult transportation of existing hole cleaning equipment.

[0004] To achieve the above objectives, a special secondary cleaning and unblocking device for delayed sealing of coal seam boreholes is provided, comprising a support unit and a slag discharge unit.

[0005] The slag discharge unit includes a drill bit, an auger, a drive shaft, a control box, and a mobile trolley; the drill bit is fixed to the front end of the auger, and the rear end of the auger is rigidly connected to the drive shaft and driven to rotate by the drive shaft; the drive shaft is mounted on the control box and electrically connected to the control box, and the control box is fixedly installed on the mobile trolley; the auger is a hollow bare spiral structure, with the drilled hole serving as the slag discharge channel;

[0006] The support unit is a split-type splicing structure, comprising a steering section, a directional movement adjustment section, and an angle adjustment section sequentially along the auger's feed direction. The angle adjustment section has a hollow guide channel for the auger to pass through, and the bottom of the hollow guide channel is equipped with multiple sets of telescopic support legs for adjusting the auger's feed angle to match the drilling angle. The directional movement adjustment section has a hollow feed channel for the auger to pass through, and the inner wall of the hollow feed channel is machined with internal threads, forming a threaded feed limiting structure for use with the auger. The screw conveyor blades mesh to constrain and control the screw feed and retraction of the auger. The bottom of the hollow feed channel is also equipped with multiple sets of telescopic support legs to adapt to the height of the angle adjustment section and the steering section. The steering section is provided with a hollow steering channel for the auger to pass through. The hollow steering channel has a curved configuration to guide the auger to change its direction of travel, so that the auger turns from the axial direction of the roadway to the radial direction of the roadway. The bottom front end of the steering section is equipped with telescopic support legs, and the tail end of the steering section is provided with a retractable tail hose.

[0007] In the above scheme: the overall length of the angle adjustment part is 200~300mm, and the hollow guide channel includes a first semi-circular bottom and a first cover plate. Both the first semi-circular bottom and the first cover plate are tubular structures with a semi-circular cross-section. First connecting beams are symmetrically fixed on both sides of the first semi-circular bottom. One side of the first connecting beam has bolt holes, and the other side of the first connecting beam is fitted with hinges and hinged to the first cover plate. The first cover plate and the first semi-circular bottom are assembled by fastening bolts, forming a complete tubular channel. This structure is compact, suitable for confined downhole working spaces, and provides a fundamental guarantee for the smooth entry of the auger into the borehole.

[0008] In the above scheme: the overall length of the directional movement adjustment part is 500~600mm. The hollow feed channel includes a second semi-circular bottom, a second cover plate, and a third cover plate. The second semi-circular bottom, the second cover plate, and the third cover plate are all tubular structures with a semi-circular cross-section. Second connecting beams are symmetrically fixed on both sides of the second semi-circular bottom. One side of the second connecting beam has bolt holes, and the front end of the other side is fitted with a hinge and hinged to the second cover plate, while the rear end is fitted with a hinge and hinged to the third cover plate. The second and third cover plates are respectively assembled with the second semi-circular bottom by fastening bolts, forming two tubular structures. The inner wall of the third cover plate has internal threads, and the thread parameters of the internal threads match the thread parameters of the auger's spiral blades. When the auger rotates forward, it moves axially forward; when it rotates reverse, it moves axially backward. Automated reciprocating movement can be completed without additional pushing equipment, effectively improving the accuracy of hole cleaning operations. This structure also ensures the stability of the auger's movement process, avoiding deviation and jamming.

[0009] In the above scheme: the length of the turning part along the radial direction of the roadway is 200~300mm, and the length along the axial direction of the roadway is 500~800mm. The hollow turning channel is a tubular structure with a cross-section of 1 / 2~3 / 4 circle. The turning part is connected to the rear side of the directional movement adjustment part and can be used to realize the 90° azimuth turning of the auger, turning the auger arranged along the axial direction of the roadway to the radial direction of the roadway, and accurately aligning with the borehole axis.

[0010] In the above scheme: the bottom of the hollow guide channel is provided with four sets of telescopic support legs arranged in a rectangular pattern; the bottom of the hollow feed channel is also provided with four sets of telescopic support legs arranged in a rectangular pattern; the bottom front end of the hollow turning channel is provided with two sets of telescopic support legs, which are distributed in a figure-eight shape on the left and right sides; each set of telescopic support legs includes an upper support leg and a lower support leg, the top end of the upper support leg is threaded to the corresponding channel, and the bottom end is threaded to the lower support leg.

[0011] The corresponding channel is equipped with a connector, and the connector is equipped with a threaded mounting hole. The upper support leg is assembled into the threaded mounting hole.

[0012] The angle adjustment section features telescopic support legs, allowing for precise adjustment of the support height of a single support leg by unscrewing it. This adjusts the horizontal tilt angle of the entire angle adjustment section, ensuring a perfect match between the device channel and the drilling tilt angle of the hole to be cleaned. The steering section also features telescopic support legs, enabling independent height adjustment and precise control of the auger's climbing height to accommodate drilling operations at different heights. The directional movement adjustment section, also equipped with telescopic support legs, has ends that can be adapted to the heights of both the angle adjustment and steering sections.

[0013] In the above scheme: a liquid hose is axially arranged inside the auger, one end of which passes through the drive shaft and is connected to the water supply system; the front end of the drill bit is a tapered cutting end with an outlet hole inclined towards the rear of the drill bit; an axial water inlet channel is arranged inside the drill bit, the other end of which is connected to the input end of the water inlet channel and rotates with the drill bit; the output end of the water inlet channel is connected to the outlet hole; cutting teeth are evenly distributed on the outer wall of the front end of the drill bit, and the rear end of the drill bit is a cylindrical connecting end. Fixed wings are provided on both sides of the cylindrical connecting end, and the installation angle of the fixed wings is perfectly matched with the angle of the auger spiral blades. The fixed wings and the auger spiral blades are locked together by fastening bolts, thereby achieving rigid fixation of the drill bit and the auger and ensuring synchronous rotation of the drill bit and the auger.

[0014] Specifically, the inclination angle of the liquid outlet can be 35°. The design of the liquid outlet being inclined at 35° relative to the horizontal line and facing the rear of the drill bit allows the high-pressure liquid to spray out through the liquid outlet. On the one hand, it can wet the drill cuttings in the hole, completely suppress dust flying during the hole cleaning process, and achieve dust-free operation. On the other hand, it can use the reaction force of the liquid jet to provide forward thrust for the drill bit, reduce the feed resistance of the auger, and improve the hole cleaning efficiency.

[0015] Cutting teeth can cut and break up solidified and accumulated drill cuttings and coal blocks inside the borehole, solving the problem of difficult-to-clean caulking. The fixed wing serves as a connector, facilitating the installation and fixation of the auger and drill bit.

[0016] In the above scheme: the angle adjustment part and the directional movement adjustment part, and the directional movement adjustment part and the steering part are all connected by end hoses; the tail hose is a corrugated shrink tube that can automatically shrink under the push of the moving trolley; and strip-shaped slag discharge windows are opened on both the first semi-circular bottom and the second semi-circular bottom.

[0017] The flexible connection between the two sections is achieved by using a flexible hose at the end, which further constrains the movement trajectory of the auger and facilitates the adjustment of the azimuth angle of the auger entering the borehole. This allows the auger's forward direction to be adapted to boreholes with different azimuth angles and inclination angles, preventing the auger from shifting or shaking at the connection point and improving the overall guiding accuracy.

[0018] The mobile trolley can move automatically under the action of threaded feed, and the tail hose can retract automatically under the drive of the equipment, without the need for manual pushing and pulling, thus reducing the workload.

[0019] If the drill cuttings discharged from the borehole by the auger fall onto the semi-circular bottom plate, they can automatically fall to the roadway floor through the strip-shaped cuttings discharge window, thus preventing the drill cuttings from accumulating inside the support unit and causing blockage.

[0020] In the above scheme: the control box is connected to the underground compressed air pipeline and the water supply system, and integrates the functions of speed regulation, water pressure regulation, start-stop control and forward and reverse rotation control. The speed is set with three levels: fast, medium and slow. The water supply system is set with three levels of water pressure: high, medium and low, as well as a pulse water supply mode.

[0021] The drive shaft includes a pneumatic motor and a hollow shaft. The liquid hose movably passes through the hollow shaft and is connected to the water supply system. A driven gear is mounted on the hollow shaft. The output end of the pneumatic motor is equipped with a driving gear that meshes with the driven gear. The input end of the pneumatic motor is connected to the downhole compressed air pipeline. The downhole compressed air pipeline can provide power to the pneumatic motor, drive the driving gear to rotate, and then drive the driven gear and the hollow shaft to rotate. The rear end of the auger is rigidly connected to the hollow shaft and can rotate synchronously with the hollow shaft.

[0022] The high water pressure setting is suitable for working conditions where there is a large amount of drill cuttings and the drill bit is difficult to feed. It uses high-pressure water flow to disperse the solidified drill cuttings. The medium water pressure setting is the normal operating setting, suitable for normal drilling and cuttings removal operations. The low water pressure setting is suitable for working conditions where there is water accumulation or seepage in the borehole itself, preventing excessive water flow from causing mud and water to overflow from the hole. The pulse water supply mode can intermittently impact the drill cuttings, improving the breaking and cleaning effect of the hardened drill cuttings.

[0023] This invention also proposes a method for cleaning coal seam boreholes after delayed sealing, employing the aforementioned secondary cleaning and unblocking device specifically designed for delayed sealing of coal seam boreholes, comprising the following steps:

[0024] S1. Assembly and debugging of support unit: According to the inclination, height and orientation of the hole to be cleaned, adjust the telescopic support legs of the angle adjustment part and the steering part so that the front end of the angle adjustment part is axially aligned with the hole opening; then, assemble and install the angle adjustment part, the directional movement adjustment part and the steering part in sequence to complete the assembly of the support unit.

[0025] S2. Slag removal unit installation: The auger equipped with a drill bit and a built-in liquid hose is sequentially passed through the tail hose, the steering part, the directional movement adjustment part and the angle adjustment part, and inserted into the borehole to be cleaned.

[0026] S3. Power Connection and Equipment Trial Operation: Connect the downhole compressed air pipeline and water supply system to the corresponding interface of the control box; start the control box and alternately perform forward and reverse rotation at a slow speed to test the smoothness of the auger feed and retraction; adjust the water supply pressure of each gear in sequence, check the liquid discharge status of the liquid outlet of the drill bit, and confirm that the equipment is normal.

[0027] S4. Segmented Circulation Hole Cleaning Operation: Lock all cover plates, control the auger to move forward a set distance using slow speed and forward rotation mode; after moving forward to the set distance, unlock the third cover plate, switch to medium or fast speed, and complete the discharge of drill cuttings in this section; after relocking the third cover plate, continue to move the auger forward, repeating the cycle until the hole cleaning operation of the entire sealing section is completed; during the operation, switch the water supply pressure and water supply mode according to the drill cuttings condition;

[0028] S5. Equipment Retraction and Recovery: Shut down the water supply system, switch to reverse mode, lock the third cover plate, and retract the auger and drill bit at a slow speed; after the drill bit is completely withdrawn, disassemble the auger and support unit, disassemble the components of the support unit, and complete the equipment recovery.

[0029] In the above scheme: In step S1, the angle adjustment part is positioned 300mm away from the borehole opening on the side closest to the borehole to prevent drill cuttings from being directly discharged onto the part and causing accumulation and blockage; In step S4, the auger moves forward a distance of 500~1000mm at a time to avoid excessive resistance and equipment damage caused by excessive forward movement at a time; Under normal operating conditions, the medium water pressure mode is used for water supply, while the low water pressure mode is used when there is water accumulation or seepage in the borehole itself; When the drill cuttings are caking or the feed is obstructed, the high water pressure mode is switched to, and pulse water supply mode is used in conjunction with it.

[0030] The beneficial effects of this invention are:

[0031] 1. Strong adaptability to working conditions: The split-type support structure, with adjustable angle, height, and axial / radial steering, can adapt to coal seam boreholes with different inclination angles, heights, and orientations underground. This solves the problems of poor adaptability and positioning difficulties of traditional borehole cleaning equipment, making it widely applicable, especially suitable for conventional underground working conditions where roadways and boreholes are arranged perpendicularly. 2. Thorough and reliable cleaning: The operation mode, which uses a conical drill bit to break up hardened drill cuttings and relies on a bare auger to directly use the borehole as a slag discharge channel, eliminates the risk of pipe blockage. Broken coal and rock debris falling from the borehole wall can be stably discharged by the spiral blades. Compared to auger structures with casing, bare augers do not have external casing obstruction, and slag falling from the borehole wall can be directly transported and discharged by the spiral blades. If an external casing is added, slag falling from the casing is easily stuck between the casing and the borehole wall, making it difficult to clean and significantly weakening the cleaning effect. The bare auger structure effectively avoids these defects. 3. Low equipment wear: The extendable tail hose isolates the auger from the tunnel floor, avoiding unnecessary friction and wear. 4. High degree of automation and low labor intensity: Relying on the threaded feed limit structure of the third cover plate, combined with the forward and reverse control of the control box, the auger can automatically feed and retract, eliminating the need for multiple operators and significantly reducing the labor intensity of workers while improving hole cleaning efficiency. 5. Convenient assembly, disassembly, and transportation, and strong practicality: The device adopts a split-type splicing structure, making assembly and disassembly simple; the bare auger eliminates the external sleeve, reducing the overall size of the equipment and facilitating coiling and storage; the entire unit can be mounted on a mobile cart for flexible transportation to various work positions, adapting to confined underground working spaces, eliminating the need for large drilling rigs, and significantly reducing construction costs. Attached Figure Description

[0032] Figure 1 This is a structural schematic diagram of the support unit.

[0033] Figure 2 This is a schematic diagram of the slag discharge unit.

[0034] Figure 3 This is a structural diagram of the rear end of the slag discharge unit.

[0035] Figure 4 This is a schematic diagram of the front end of the slag discharge unit.

[0036] Figure 5 This is a schematic diagram of the layout of the liquid outlet holes.

[0037] Figure 6 This is a schematic diagram of the invention in operation (auger with built-in liquid hose).

[0038] Figure 7 This is a schematic diagram of the invention in operation (auger without liquid hose). Detailed Implementation

[0039] Example 1

[0040] like Figure 1 As shown in Figure 6, a special secondary cleaning and unblocking device for delayed sealing of coal seam boreholes mainly consists of a support unit and a slag discharge unit.

[0041] The slag removal unit includes a drill bit 1, an auger 2, a drive shaft 3, a control box 4, and a mobile cart 5. The drill bit 1 is fixed to the front end of the auger 2, and the rear end of the auger 2 is rigidly connected to the drive shaft 3 and driven to rotate by the drive shaft 3. The drive shaft 3 is mounted on the control box 4 and electrically connected to the control box 4. The control box 4 is fixedly installed on the mobile cart 5. The auger 2 is a hollow bare spiral structure with a drill hole 19 as the slag removal channel. A liquid hose 6 is arranged axially inside the auger 2. One end of the liquid hose 6 passes through the drive shaft 3 and is connected to the water supply system 10. The front end of the drill bit 1 is a tapered cutting end with an outlet hole 11 inclined towards the rear of the drill bit. An axial water inlet channel is arranged inside the drill bit 1. The other end of the liquid hose 6 is connected to the input end of the water inlet channel and forms a rotational fit with the drill bit 1 (which can be achieved by connecting the high-pressure sealed rotating water tail). The output end of the water inlet channel is connected to the outlet hole 11.

[0042] The support unit is a split-type splicing structure, which includes a steering part 7, a directional movement adjustment part 8, and an angle adjustment part 9 in sequence along the feed direction of the auger 2. The angle adjustment part 9 is provided with a hollow guide channel for the auger 2 to pass through. The bottom of the hollow guide channel is equipped with multiple sets of telescopic support legs 12, which are used to adjust the feed angle of the auger 2 to match the borehole angle 19. The directional movement adjustment part 8 is provided with a hollow feed channel for the auger 2 to pass through. The inner wall of the hollow feed channel is machined with internal threads to form a threaded feed limiting structure, which is used to interact with the auger 2. The spiral blades mesh to constrain and control the spiral feed and retraction of the auger 2. The bottom of the hollow feed channel is also equipped with multiple sets of telescopic support legs 12 to adapt to the height of the angle adjustment part 9 and the turning part 7. The turning part 7 is provided with a hollow turning channel for the auger 2 to pass through. The hollow turning channel has a curved configuration to guide the auger 2 to change its direction of travel, so that the auger 2 turns from the axial direction of the roadway to the radial direction of the roadway. The bottom front end of the turning part 7 is equipped with telescopic support legs 12, and the tail end of the turning part 7 is provided with a retractable tail hose 13.

[0043] The angle adjustment section 9 has an overall length of 200-300mm. The hollow guide channel includes a first semi-circular bottom 91 and a first cover plate 92. Both the first semi-circular bottom 91 and the first cover plate 92 are tubular structures with a semi-circular cross-section. First connecting beams 93 are symmetrically fixed on both sides of the first semi-circular bottom 91. One side of the first connecting beam 93 has bolt holes, and the other side of the first connecting beam 93 is fitted with hinges and hinged to the first cover plate 92. The first cover plate 92 and the first semi-circular bottom 91 are assembled by fastening bolts to form a complete tubular channel. This structure is compact and suitable for the narrow working space downhole, providing a basic guarantee for the smooth entry of the auger 2 into the borehole.

[0044] The overall length of the directional movement adjustment section 8 is 500~600mm. The hollow feed channel includes a second semi-circular bottom 81, a second cover plate 82, and a third cover plate 83. The second semi-circular bottom 81, the second cover plate 82, and the third cover plate 83 are all tubular structures with a semi-circular cross-section. The second connecting beams 84 are symmetrically fixed on both sides of the second semi-circular bottom 81. One side of the second connecting beam 84 has bolt holes. The front end of the other side of the second connecting beam 84 is fitted with a hinge and is hinged to the second cover plate 82. The rear end is fitted with a hinge and is hinged to the third cover plate 83. The second cover plate 82 and the third cover plate 83 are respectively assembled with the second semi-circular bottom 81 by fastening bolts to form two tubular structures. The inner wall of the third cover plate 83 is provided with internal threads. The thread parameters of the internal threads are matched with the thread parameters of the screw conveyor blades of the auger 2. When the auger 2 rotates forward, it moves forward axially, and when it rotates backward, it moves backward axially. It can complete the automated reciprocating movement without the need for additional pushing equipment, which effectively improves the accuracy of hole cleaning operations. This structure also ensures the stability of the auger 2 during movement and avoids deviation and jamming.

[0045] The turning section 7 has a radial length of 200-300 mm and an axial length of 500-800 mm. The hollow turning channel is a tubular structure with a cross-section of 1 / 2 to 3 / 4 circle. The turning section 7 is connected to the rear side of the directional movement adjustment section 8 and can be used to achieve 290° azimuth turning of the auger 2, turning the auger 2 arranged along the axial direction of the roadway to the radial direction of the roadway, and accurately aligning with the axial direction of the borehole 19.

[0046] The bottom of the hollow guide channel is provided with four sets of telescopic support legs 12 arranged in a rectangular pattern. The bottom of the hollow feed channel is also provided with four sets of telescopic support legs 12 arranged in a rectangular pattern. The bottom front end of the hollow turning channel is provided with two sets of telescopic support legs 12. The two sets of telescopic support legs 12 are distributed in a figure-eight shape on the left and right sides. Each set of telescopic support legs 12 includes an upper support leg and a lower support leg. The top end of the upper support leg is threaded to the corresponding channel, and the bottom end is threaded to the lower support leg.

[0047] The corresponding channel is equipped with a connector, and the connector is equipped with a threaded mounting hole. The upper support leg is assembled into the threaded mounting hole.

[0048] The angle adjustment section 9 is equipped with telescopic support legs 12. By unscrewing the support legs, the support height of a single support leg can be precisely adjusted, thereby adjusting the horizontal tilt angle of the entire angle adjustment section 9 to perfectly match the tilt angle of the device channel with the borehole 19 to be cleaned. The steering section 7 is also equipped with telescopic support legs 12, allowing for independent adjustment of the support height and precise adjustment of the auger 2's climbing height to adapt to the operational needs of boreholes 19 at different heights. The directional movement adjustment section 8 is also equipped with telescopic support legs 12, with its two ends respectively adaptable to the heights of the angle adjustment section 9 and the steering section 7.

[0049] Specifically, the outlet hole 11 has an inclination angle of 35°; the front outer wall of the drill bit 1 is evenly distributed with cutting teeth 14, and the rear end of the drill bit 1 is a cylindrical connecting end. Fixed wings 15 are provided on both sides of the cylindrical connecting end. The installation angle of the fixed wings 15 perfectly matches the angle of the spiral blades of the auger 2. The fixed wings 15 and the spiral blades of the auger 2 are locked together with fastening bolts, thereby achieving rigid fixation of the drill bit 1 and the auger 2, ensuring synchronous rotation of the drill bit 1 and the auger 2. The design of the outlet hole 11, which is inclined at 35° relative to the horizontal line and faces the rear of the drill bit, allows the high-pressure liquid sprayed out through the outlet hole 11 to, on the one hand, wet the drill cuttings inside the hole, completely suppressing dust during the hole cleaning process and achieving dust-free operation; on the other hand, the reaction force of the liquid jet can provide forward thrust for the drill bit 1, reducing the feed resistance of the auger 2 and improving the hole cleaning efficiency. The cutting teeth 14 can cut and break up the solidified and accumulated drill cuttings and coal blocks inside the borehole 19, solving the problem of difficult-to-clean caking drill cuttings. The fixed wing 15 serves as a connector, facilitating the installation and fixation of the auger 2 and the drill bit 1.

[0050] Specifically, the angle adjustment part 9 and the directional movement adjustment part 8, and the directional movement adjustment part 8 and the steering part 7 are connected by the end hose 16; the tail hose 13 is a corrugated shrink tube that can automatically shrink under the push of the moving trolley 5; and strip-shaped slag discharge windows 17 are opened on the first semi-circular bottom 91 and the second semi-circular bottom 81.

[0051] The flexible connection between the two sections is achieved through the end hose 16, which further constrains the movement trajectory of the auger 2. At the same time, it is convenient to adjust the azimuth angle of the auger 2 entering the borehole 19, so that the forward direction of the auger 2 can be adapted to boreholes 19 with different azimuth angles and different inclination angles, avoiding the auger 2 from shifting or shaking at the connection position, and improving the overall guiding accuracy.

[0052] The mobile trolley 5 can move automatically under the action of threaded feed, and the tail hose 13 can retract automatically under the drive of the equipment, without the need for manual pushing and pulling, thus reducing the workload.

[0053] If the drill cuttings discharged from borehole 19 by screw conveyor 2 fall onto the semi-circular bottom plate, they can automatically fall to the roadway floor through the strip-shaped cuttings discharge window 17, thus preventing the drill cuttings from accumulating inside the support unit and causing blockage.

[0054] Specifically, the control box 4 is connected to the underground compressed air pipeline 18 and the water supply system 10, integrating speed regulation, water pressure regulation, start-stop control and forward / reverse control functions. The speed is set with three levels: fast, medium and slow. The water supply system is set with three water pressure modes: high, medium and low, as well as a pulse water supply mode.

[0055] The drive shaft 3 includes a pneumatic motor and a hollow shaft. The liquid hose 6 moves through the hollow shaft and is connected to the water supply system 10. A driven gear is mounted on the hollow shaft. The output end of the pneumatic motor is equipped with a drive gear that meshes with the driven gear. The input end of the pneumatic motor is connected to the downhole compressed air pipeline 18. The downhole compressed air pipeline 18 can provide power to the pneumatic motor, drive the drive gear to rotate, and then drive the driven gear and the hollow shaft to rotate. The rear end of the auger 2 is rigidly connected to the hollow shaft and can rotate synchronously with the hollow shaft.

[0056] The high water pressure setting is suitable for working conditions where there is a large amount of drill cuttings and the drill bit is difficult to feed. It uses high-pressure water flow to disperse the solidified drill cuttings. The medium water pressure setting is the normal operating setting, suitable for normal drilling and cuttings removal operations. The low water pressure setting is suitable for working conditions where there is water accumulation or seepage in the borehole itself, preventing excessive water flow from causing mud and water to overflow from the hole. The pulse water supply mode can intermittently impact the drill cuttings, improving the breaking and cleaning effect of the hardened drill cuttings.

[0057] A method for cleaning coal seam boreholes after delayed sealing, employing the aforementioned dedicated secondary cleaning and unblocking device for coal seam boreholes after delayed sealing, mainly consists of the following steps:

[0058] S1. Support Unit Assembly and Adjustment: Based on the inclination angle, height, and orientation of the borehole 19 to be cleaned, adjust the telescopic support legs 12 of the angle adjustment part 9 and the steering part 7 to axially align the front end of the angle adjustment part 9 with the borehole opening of the borehole 19; sequentially assemble and install the angle adjustment part 9, the directional movement adjustment part 8, and the steering part 7 to complete the support unit assembly. Specifically, the angle adjustment part 9 is positioned 300mm away from the borehole opening on the side closest to the borehole 19 to prevent drill cuttings from directly accumulating and causing blockage.

[0059] S2. Slag removal unit installation: The auger equipped with a drill bit and a built-in liquid hose is sequentially passed through the tail hose 13, the steering part 7, the directional movement adjustment part 8 and the angle adjustment part 9, and extended into the drill hole 19 to be cleaned.

[0060] S3. Power Connection and Equipment Trial Operation: Connect the downhole compressed air pipeline 18 and water supply system 10 to the corresponding interfaces of the control box 4; start the control box 4 and alternately perform forward and reverse rotation at a slow speed to test the smoothness of the screw conveyor 2's feed and retraction; adjust the water supply pressure of each gear in sequence, check the liquid discharge status of the liquid outlet hole 11 on the drill bit, and confirm that the equipment is normal.

[0061] S4. Segmented cyclic hole cleaning operation: Lock all cover plates, control the auger 2 to move forward a set distance at slow speed and forward rotation mode; after moving forward to the position, unlock the third cover plate 83, switch to medium or fast speed, and complete the discharge of drill cuttings in this section; after relocking the third cover plate 83, continue to move the auger 2 forward, repeat the cycle until the hole cleaning operation of the entire sealing section is completed; during the operation, switch the water supply pressure and water supply mode according to the drill cuttings condition.

[0062] Specifically, the single forward movement distance of the auger 2 is 500~1000mm to avoid excessive resistance and equipment damage caused by excessive single forward movement distance. Under normal operating conditions, the medium water pressure mode is used for water supply. When there is water accumulation or seepage in the borehole 19 itself, the low water pressure mode is used for water supply. When the drill cuttings are caking or the feed is obstructed, the high water pressure mode is switched to, and pulse water supply mode is used in conjunction with it.

[0063] S5. Equipment Retraction and Recovery: Shut down the water supply system 10, switch to reverse mode, lock the third cover plate 83, and retract the auger 2 and drill bit 1 at a slow speed; after the drill bit 1 is completely withdrawn, disassemble the auger 1 and support unit, disassemble the components of the support unit, and complete the equipment recovery.

[0064] Example 2

[0065] like Figure 7 As shown, a secondary cleaning and unblocking device for delayed sealing of coal seam boreholes mainly consists of a support unit and a slag discharge unit.

[0066] The slag removal unit includes a drill bit 1, an auger 2, a drive shaft 3, a control box 4, and a mobile trolley 5. The drill bit is fixed to the front end of the auger 2, and the rear end of the auger 2 is rigidly connected to the drive shaft 3, which drives the auger 2 to rotate. The drive shaft 3 is mounted on the control box 4 and electrically connected to the control box 4. The control box 4 is fixedly installed on the mobile trolley 5. The auger 2 is a hollow, bare spiral structure, with 19 drilled holes serving as the slag removal channel.

[0067] The support unit is a split-type splicing structure, which includes a steering section 7, a directional movement adjustment section 8, and an angle adjustment section 9 sequentially along the feed direction of the auger 2. The angle adjustment section 9 has a hollow guide channel for the auger 2 to pass through. The bottom of the hollow guide channel is equipped with multiple sets of telescopic support legs 12, which are used to adjust the feed angle of the auger 2 to match the borehole angle 19. The directional movement adjustment section 8 has a hollow feed channel for the auger 2 to pass through. The inner wall of the hollow feed channel is machined with internal threads to form a threaded feed limiting structure, which is used to engage with the spiral blades of the auger 2 to constrain and control the spiral feed and retraction of the auger 2. The bottom of the hollow feed channel is also equipped with multiple sets of telescopic support legs 12 to adapt to the height of the angle adjustment section 9 and the steering section 7. The turning section 7 is provided with a hollow turning channel for the auger 2 to pass through. The hollow turning channel has a curved configuration to guide the auger 2 to change its direction of travel, so that the auger 2 turns from the axial direction of the roadway to the radial direction of the roadway. The bottom front end of the turning section 7 is equipped with a telescopic support leg 12, and the tail end of the turning section 7 is provided with a telescopic tail hose 13.

[0068] The angle adjustment section 9 has an overall length of 200-300mm. The hollow guide channel includes a first semi-circular bottom 91 and a first cover plate 92. Both the first semi-circular bottom 91 and the first cover plate 92 are tubular structures with a semi-circular cross-section. First connecting beams 93 are symmetrically fixed on both sides of the first semi-circular bottom 91. One side of the first connecting beam 93 has bolt holes, and the other side of the first connecting beam 93 is fitted with hinges and hinged to the first cover plate 92. The first cover plate 92 and the first semi-circular bottom 91 are assembled by fastening bolts to form a complete tubular channel. This structure is compact and suitable for the narrow working space downhole, providing a basic guarantee for the smooth entry of the auger 2 into the borehole.

[0069] The overall length of the directional movement adjustment section 8 is 500~600mm. The hollow feed channel includes a second semi-circular bottom 81, a second cover plate 82, and a third cover plate 83. The second semi-circular bottom 81, the second cover plate 82, and the third cover plate 83 are all tubular structures with a semi-circular cross-section. The second connecting beams 84 are symmetrically fixed on both sides of the second semi-circular bottom 81. One side of the second connecting beam 84 has bolt holes. The front end of the other side of the second connecting beam 84 is fitted with a hinge and is hinged to the second cover plate 82. The rear end is fitted with a hinge and is hinged to the third cover plate 83. The second cover plate 82 and the third cover plate 83 are respectively assembled with the second semi-circular bottom 81 by fastening bolts to form two tubular structures. The inner wall of the third cover plate 83 is provided with internal threads. The thread parameters of the internal threads are matched with the thread parameters of the screw conveyor blades of the auger 2. When the auger 2 rotates forward, it moves forward axially, and when it rotates backward, it moves backward axially. It can complete the automated reciprocating movement without the need for additional pushing equipment, which effectively improves the accuracy of hole cleaning operations. This structure also ensures the stability of the auger 2 during movement and avoids deviation and jamming.

[0070] The turning section 7 has a radial length of 200-300mm and an axial length of 500-800mm along the roadway. The hollow turning channel is a tubular structure with a cross-section of 1 / 2 to 3 / 4 circle. The turning section 7 is connected to the rear side of the directional movement adjustment section 8 and is mainly used to realize the 290° azimuth turning of the auger 2, turning the auger 2 arranged along the roadway axial direction to the roadway radial direction, and accurately aligning with the axial direction of the borehole 19.

[0071] The bottom of the hollow guide channel is provided with four sets of telescopic support legs 12 arranged in a rectangular pattern. The bottom of the hollow feed channel is also provided with four sets of telescopic support legs 12 arranged in a rectangular pattern. The bottom front end of the hollow turning channel is provided with two sets of telescopic support legs 12. The two sets of telescopic support legs 12 are distributed in a figure-eight shape on the left and right sides. Each set of telescopic support legs 12 includes an upper support leg and a lower support leg. The top end of the upper support leg is threaded to the corresponding channel, and the bottom end is threaded to the lower support leg.

[0072] The corresponding channel is equipped with a connector, and the connector is equipped with a threaded mounting hole. The upper support leg is assembled into the threaded mounting hole.

[0073] The angle adjustment section 9 is equipped with telescopic support legs 12. By unscrewing the support legs, the support height of a single support leg can be precisely adjusted, thereby adjusting the horizontal inclination of the entire angle adjustment section to perfectly match the inclination angle of the device channel with the borehole 19 to be cleaned. The steering section 7 is also equipped with telescopic support legs 12, allowing for independent adjustment of the support height and precise adjustment of the auger 2's climbing height to adapt to the operational needs of boreholes 19 at different heights. The directional movement adjustment section 8 is also equipped with telescopic support legs 12, with its two ends respectively adaptable to the heights of the angle adjustment section 9 and the steering section 7.

[0074] Specifically, the front end of drill bit 1 is a tapered cutting end, with evenly distributed cutting teeth 14 on its outer wall. The rear end of drill bit 1 is a cylindrical connecting end, with fixed wings 15 on both sides. The installation angle of the fixed wings 15 perfectly matches the angle of the spiral blades of auger 2. The fixed wings 15 and the spiral blades of auger 2 are locked together by fastening bolts, thereby achieving rigid fixation of drill bit 1 and auger 2 and ensuring synchronous rotation of drill bit 1 and auger 2. The cutting teeth 14 can cut and break up the solidified and accumulated drill cuttings and coal blocks in the borehole 19, solving the problem of difficult-to-clean cambered drill cuttings. The fixed wings 15 serve as connecting parts, facilitating the installation and fixation of auger 2 and drill bit 1.

[0075] Specifically, the angle adjustment section 9 and the directional movement adjustment section 8, as well as the directional movement adjustment section 8 and the steering section 7, are connected via end hoses 16. The end hoses 16 provide flexible connection between the two sections, further constraining the movement trajectory of the auger 2 and facilitating adjustment of the azimuth angle at which the auger 2 enters the borehole 19. This allows the auger 2's forward direction to adapt to boreholes 19 with different azimuth and inclination angles, preventing the auger 2 from shifting or wobbling at the connection point and improving overall guiding accuracy.

[0076] Specifically, the tail hose 13 is a corrugated shrinkable tube that can automatically shrink under the push of the moving trolley 5. The moving trolley 5 can move automatically under the action of threaded feed, and the tail hose 13 can automatically shrink under the drive of the equipment, both of which do not require manual pushing and pulling, thus reducing the labor intensity.

[0077] Specifically, both the first semicircular bottom 91 and the second semicircular bottom 81 are provided with strip-shaped slag discharge windows 17. If the drill cuttings discharged from the borehole 19 by the screw conveyor 2 fall onto the semicircular bottom plate, they can automatically fall to the roadway floor through the strip-shaped slag discharge windows 17, thus preventing the drill cuttings from accumulating inside the support unit and causing blockage.

[0078] Specifically, the control box 4 is connected to the downhole compressed air pipeline 18, which integrates speed regulation, start / stop control and forward / reverse control functions. The speed is set with three levels: fast, medium and slow. The drive shaft 3 includes a pneumatic motor. The output end of the pneumatic motor is rigidly connected to the rear end of the auger 2, and the input end of the pneumatic motor is connected to the downhole compressed air pipeline 18. The downhole compressed air pipeline 18 can provide power to the pneumatic motor, drive the output end of the pneumatic motor to rotate, and thus drive the auger 2 to rotate. The structure is simple and the layout is convenient.

[0079] A method for cleaning coal seam boreholes after delayed sealing, employing the aforementioned dedicated secondary cleaning and unblocking device for coal seam boreholes after delayed sealing, mainly consists of the following steps:

[0080] S1. Support Unit Assembly and Adjustment: Based on the inclination angle, height, and orientation of the borehole 19 to be cleaned, adjust the telescopic support legs 12 of the angle adjustment part 9 and the steering part 7 to axially align the front end of the angle adjustment part 9 with the borehole opening of the borehole 19; sequentially assemble and install the angle adjustment part 9, the directional movement adjustment part 8, and the steering part 7 to complete the support unit assembly. Specifically, the angle adjustment part 9 is positioned 300mm away from the borehole opening on the side closest to the borehole 19 to prevent drill cuttings from directly accumulating and causing blockage.

[0081] S2. Slag discharge unit installation: The auger 2 is sequentially passed through the tail hose 13, the steering part 7, the directional movement adjustment part 8 and the angle adjustment part 9, and inserted into the borehole 19 to be cleaned.

[0082] S3. Power connection and equipment trial operation: Connect the underground compressed air pipeline 18 to the corresponding interface of the control box 4; start the control box 4 and alternately perform forward and reverse rotation at a slow speed to test the smoothness of the screw conveyor 2's feed and retraction.

[0083] S4. Segmented cyclic hole cleaning operation: Lock all cover plates, control the auger 2 to move forward a set distance in slow speed and forward mode; after moving forward to the position, unlock the third cover plate 83, switch to medium or fast speed, and complete the discharge of drill cuttings in this section; after relocking the third cover plate 83, continue to move the auger 2 forward, repeat the cycle until the hole cleaning operation of the entire sealing section is completed.

[0084] Specifically, the auger 2 should move forward 500-1000mm at a time to avoid excessive resistance and damage to the equipment caused by excessive forward movement.

[0085] S5. Equipment retraction and recovery: Switch to reverse mode, lock the third cover plate 83 and retract the auger 2 and drill bit 1 at a slow speed; after the drill bit 1 is completely withdrawn, disassemble the auger 1 and the support unit, disassemble the components of the support unit, and complete the equipment recovery.

Claims

1. A secondary cleaning and unblocking device for delayed sealing of coal seam boreholes, characterized in that: Includes support units and slag removal units; The slag removal unit includes a drill bit (1), an auger (2), a drive shaft (3), a control box (4), and a mobile cart (5); the drill bit (1) is fixed to the front end of the auger (2), and the rear end of the auger (2) is rigidly connected to the drive shaft (3) and is driven to rotate by the drive shaft (3); the drive shaft (3) is mounted on the control box (4) and electrically connected to the control box (4), and the control box (4) is fixedly installed on the mobile cart (5); the auger (2) is a hollow bare spiral structure, with the drill hole (19) channel as the slag removal channel; The support unit is a split-type splicing structure, which includes a steering part (7), a directional movement adjustment part (8), and an angle adjustment part (9) in sequence along the feed direction of the auger (2); the angle adjustment part (9) is provided with a hollow guide channel for the auger (2) to pass through, and the bottom of the hollow guide channel is equipped with multiple sets of telescopic support legs (12) for adjusting the feed angle of the auger (2) to match the borehole (19) angle; the directional movement adjustment part (8) is provided with a hollow feed channel for the auger (2) to pass through, and the inner wall of the hollow feed channel is machined with internal threads to form a threaded feed limiting structure for use with the auger (2) The spiral blades of the auger (2) mesh to constrain and control the spiral feed and retraction of the auger (2). The bottom of the hollow feed channel is also equipped with multiple sets of telescopic support legs (12) to adapt to the height of the angle adjustment part (9) and the turning part (7). The turning part (7) is provided with a hollow turning channel for the auger (2) to pass through. The hollow turning channel is curved and is used to guide the auger (2) to change its direction of travel, so that the auger (2) turns from the axial direction of the roadway to the radial direction of the roadway. The bottom front end of the turning part (7) is equipped with telescopic support legs (12), and the tail end of the turning part (7) is provided with a retractable tail hose (13).

2. The secondary cleaning and unblocking device for delayed sealing of coal seam boreholes according to claim 1, characterized in that: The angle adjustment part (9) has an overall length of 200~300mm. The hollow guide channel includes a first semi-circular bottom (91) and a first cover plate (92). Both the first semi-circular bottom (91) and the first cover plate (92) are tubular structures with a semi-circular cross section. The first connecting beams (93) are symmetrically fixed on both sides of the first semi-circular bottom (91). One side of the first connecting beam (93) has bolt holes, and the other side of the first connecting beam (93) is fitted with hinges and hinged to the first cover plate (92). The first cover plate (92) and the first semi-circular bottom (91) are assembled by fastening bolts to form a complete tubular channel.

3. The secondary cleaning and unblocking device for delayed sealing of coal seam boreholes according to claim 1, characterized in that: The overall length of the directional movement adjustment part (8) is 500~600mm. The hollow feed channel includes a second semi-circular bottom (81), a second cover plate (82) and a third cover plate (83). The second semi-circular bottom (81), the second cover plate (82) and the third cover plate (83) are all tubular structures with a semi-circular cross section. The second semi-circular bottom (81) is symmetrically fixed with a second connecting beam (84) on both sides. One side of the second connecting beam (84) has a bolt hole. The front end of the other side of the second connecting beam (84) is fitted with a hinge and is hinged to the second cover plate (82) through a hinge. The rear end is fitted with a hinge and is hinged to the third cover plate (83) through a hinge. The second cover plate (82) and the third cover plate (83) are respectively assembled with the second semi-circular bottom (81) by fastening bolts to form two tubular structures. The inner wall of the third cover plate (83) is provided with an internal thread. The thread parameters of the internal thread are matched with the thread parameters of the spiral blade of the auger (2).

4. The secondary cleaning and unblocking device for delayed sealing of coal seam boreholes according to claim 1, characterized in that: The length of the turning part (7) along the radial direction of the roadway is 200~300mm and the length along the axial direction of the roadway is 500~800mm. The hollow turning channel is a tubular structure with a cross-section of 1 / 2~3 / 4 circle.

5. The secondary cleaning and unblocking device for delayed sealing of coal seam boreholes according to claim 1, characterized in that: The bottom of the hollow guide channel is provided with four sets of telescopic support legs (12) arranged in a rectangular pattern. The bottom of the hollow feed channel is also provided with four sets of telescopic support legs (12) arranged in a rectangular pattern. The bottom front end of the hollow turning channel is provided with two sets of telescopic support legs (12). The two sets of telescopic support legs (12) are distributed in a figure-eight shape on the left and right sides. Each set of telescopic support legs (12) includes an upper support leg and a lower support leg. The top end of the upper support leg is threaded to the corresponding channel, and the bottom end is threaded to the lower support leg.

6. The secondary cleaning and unblocking device for delayed sealing of coal seam boreholes according to claim 1, characterized in that: The auger (2) has a liquid hose (6) arranged axially inside. One end of the liquid hose (6) passes through the drive shaft (3) and is connected to the water supply system (10). The front end of the drill bit (1) is a tapered cutting end. The tapered cutting end has a liquid outlet hole (11) that is inclined toward the rear side of the drill bit. The drill bit (1) has a water inlet channel arranged axially inside. The other end of the liquid hose (6) is connected to the input end of the water inlet channel and forms a rotational fit with the drill bit (1). The output end of the water inlet channel is connected to the... The liquid outlet (11) is connected; the front end of the drill bit (1) is evenly provided with cutting teeth (14), and the rear end of the drill bit (1) is a cylindrical connecting end. Both sides of the cylindrical connecting end are provided with fixed wings (15). The installation angle of the fixed wings (15) is completely matched with the angle of the spiral blades of the auger (2). The fixed wings (15) and the spiral blades of the auger (2) are locked together by fastening bolts, thereby achieving rigid fixation of the drill bit (1) and the auger (2) and ensuring that the drill bit (1) and the auger (2) rotate synchronously.

7. The secondary cleaning and unblocking device for delayed sealing of coal seam boreholes according to claim 6, characterized in that: The angle adjustment part (9) and the directional movement adjustment part (8), and the directional movement adjustment part (8) and the steering part (7) are connected by the end hose (16); the tail hose (13) is a corrugated shrink tube that can automatically shrink under the push of the mobile trolley (5); the first semi-circular bottom (91) and the second semi-circular bottom (81) are both provided with strip-shaped slag discharge windows (17).

8. The secondary cleaning and unblocking device for delayed sealing of coal seam boreholes according to claim 7, characterized in that: The control box (4) is connected to the downhole compressed air pipeline (18) and the water supply system (10), and integrates speed regulation, water pressure regulation, start-stop control and forward and reverse rotation control functions. The speed is set with three levels: fast, medium and slow. The water supply system is set with three levels of water pressure mode: large, medium and small and pulse water supply mode. The drive shaft (3) includes a pneumatic motor and a hollow shaft. The liquid hose (6) passes through the hollow shaft and is connected to the water supply system (10). The hollow shaft is equipped with a driven gear. The output end of the pneumatic motor is equipped with a drive gear that meshes with the driven gear. The input end of the pneumatic motor is connected to the downhole compressed air pipeline (18). The downhole compressed air pipeline (18) can provide power to the pneumatic motor, drive the drive gear to rotate, and then drive the driven gear and the hollow shaft to rotate. The rear end of the auger (2) is rigidly connected to the hollow shaft and can rotate synchronously with the hollow shaft.

9. A method for cleaning coal seam boreholes with delayed sealing, characterized in that: The secondary cleaning and unblocking device for delayed sealing of coal seam boreholes as described in claim 8 includes the following steps: S1. Assembly and debugging of support unit: According to the inclination, height and orientation of the hole to be cleaned (19), adjust the telescopic support legs (12) of the angle adjustment part (9) and the turning part (7) so that the front end of the angle adjustment part (9) is axially aligned with the hole opening (19); The angle adjustment part (9), the directional movement adjustment part (8), and the steering part (7) are sequentially assembled and installed to complete the support unit assembly; S2. Slag removal unit installation arrangement: The auger equipped with a drill bit and a built-in liquid hose is inserted into the drill hole (19) of the hole to be cleaned by passing through the tail hose (13), the turning part (7), the directional movement adjustment part (8) and the angle adjustment part (9) in sequence. S3. Power connection and equipment trial operation: Connect the downhole compressed air pipeline (18) and water supply system (10) to the corresponding interface of the control box (4); start the control box (4) and alternately perform forward and reverse rotation at a slow speed to test the smoothness of the screw conveyor (2) feed and retraction; adjust the water supply pressure of each gear in sequence, check the liquid discharge status of the liquid outlet hole (11) on the drill bit, and confirm that the equipment is normal. S4. Segmented cyclic hole cleaning operation: Lock all cover plates, control the auger (2) to move forward a set distance in slow speed and forward mode; after moving forward to the position, unlock the third cover plate (83), switch to medium or fast speed, and complete the discharge of drill cuttings in this section; after locking the third cover plate (83) again, continue to move the auger (2) forward, repeat the cycle until the hole cleaning operation of the entire sealing section is completed; during the operation, switch the water supply pressure and water supply mode according to the drill cuttings condition; S5. Equipment retraction and recovery: shut off the water supply system (10), switch to reverse mode, lock the third cover plate (83) and retract the auger (2) and drill bit (1) at a slow speed; after the drill bit (1) is completely withdrawn, disassemble the auger (1) and support unit, disassemble each component of the support unit, and complete the equipment recovery.

10. The method for cleaning coal seam boreholes with delayed sealing according to claim 9, characterized in that: In step S1, the angle adjustment part (9) is positioned 300mm away from the borehole opening on the side closest to the borehole (19); in step S4, the auger (2) moves forward a distance of 500~1000mm in a single operation; in normal working conditions, the medium water pressure mode is used for water supply, and in working conditions where there is water accumulation or seepage in the borehole (19), the low water pressure mode is used for water supply; when the drill cuttings are caking and the feed is obstructed, the high water pressure mode is switched to, and pulse water supply mode is used in conjunction with it.

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