A mechanical scraping-pulsed airflow synergistic anti-clogging drill rod and its drilling method

Abstract

This invention discloses an anti-clogging drill rod with a synergistic effect of mechanical scraping and pulsed airflow, and its drilling method, belonging to the technical field of coal mine gas drainage drilling equipment. The anti-clogging drill rod mainly consists of a drill rod body and a coaxially fitted outer casing. The drill rod body contains a directional pulsed airflow duct and nozzle, while the outer casing is equipped with elastic scraping teeth, a pulverized coal inlet, and a crushed coal and stone inlet. The drilling method includes the following steps: equipment system preparation and connection, directional drilling, gas-water mixing and slag removal, equipment system debugging and preheating, torque sensor calibration, synergistic drilling, intelligent control, synergistic finishing, and acceptance evaluation. This invention solves the core problem of pulverized coal agglomeration and drilling interruption in pulverized coal seam drilling through the synergistic effect of the drill rod's self-cleaning structure and directional pulsed airflow. It is compatible with existing mainstream drilling rigs and provides technical support for efficient gas drainage from deep pulverized coal seams.

Description

Technical Field

[0001] This invention belongs to the technical field of coal mine gas drainage drilling equipment, specifically a mechanical scraping-pulse airflow synergistic anti-clogging drill rod and its drilling construction method. Background Technology

[0002] With the advancement of deep coal seam gas extraction projects, the problem of borehole plugging has become a key bottleneck restricting construction efficiency and safety. Existing technologies have the following significant shortcomings:

[0003] 1) Pulverized coal blockage: Pulverized coal particles are fine and have poor flowability. When using traditional drill rods, pulverized coal is prone to accumulate in the guide groove, forming a "coal bridge". This requires frequent work stoppages and drill retraction, resulting in low construction efficiency. Some drill holes are scrapped due to severe blockage.

[0004] 2) Drill bit damage: After the pulverized coal is piled up and compacted, the drilling torque increases sharply, exceeding the material's permissible range, causing the drill rod to bend, the threads to wear or even break, which not only increases equipment maintenance costs but also poses safety hazards.

[0005] 3) Coal clumps are difficult to break up: Existing airflow anti-blocking technologies basically use constant pressure, which makes it difficult to break up coal clumps. In addition, instantaneous high pressure can easily disturb the borehole wall and cause collapse, which will aggravate the blockage problem.

[0006] 4) High operational threshold: Existing anti-blocking technology requires professional personnel to adjust parameters, which is difficult for ordinary operators to master and adapt to complex downhole construction. Summary of the Invention

[0007] The purpose of this invention is to solve the problems existing in the prior art by providing an anti-clogging drill rod with a synergistic effect of mechanical scraping and pulsed airflow, and a drilling method thereof. This invention is a spiral drill rod integrating a dual anti-clogging mechanism of "mechanical scraping and pulsed airflow disturbance," suitable for soft, low-permeability coal seams with ultra-deep burial (800~1200m), high ground stress, and high pulverized coal content, as well as coal seam exposure sections in deep coal-bearing tunnels. Through the synergistic effect of the drill rod's self-cleaning structure and directional pulsed airflow, it solves the core problem of pulverized coal agglomeration blocking the borehole and interrupting drilling in pulverized coal seam drilling. It is compatible with existing mainstream drilling rigs and provides technical support for efficient gas extraction from deep pulverized coal seams.

[0008] This invention is achieved through the following technical solution:

[0009] One aspect of the present invention provides an anti-clogging drill pipe with mechanical scraping and pulsed airflow synergy, comprising a drill pipe body, a plurality of spiral guide grooves evenly distributed along its axial direction on the outer wall of the drill pipe body, a drill bit disposed at the head of the drill pipe body; a torque sensor disposed on the outer wall of the drill pipe body; a directional pulsed airflow duct embedded in the drill pipe body and arranged along its axial direction, a plurality of nozzles evenly distributed on the directional pulsed airflow duct, each nozzle comprising a plurality of directional pulsed airflow nozzles evenly distributed radially, the nozzle orifice of each directional pulsed airflow nozzle being disposed on the outer wall of the drill pipe body; an outer sleeve fitted outside the drill pipe body, the outer sleeve being connected to the drill pipe body. The outer casing is fixed with a coaxial connection, and a gap is left between the outer casing and the drill pipe body to form a pulverized coal exit channel. A mounting base for connecting and installing with the drilling rig is fixedly connected to the outer wall of the outer casing near the tail end. Multiple pulverized coal and stone inlets are evenly distributed and opened through the pipe wall of the outer casing near the head end. Multiple rows of elastic scraper teeth are evenly distributed and fixed on the outer wall of the outer casing along its axial direction. Multiple rows of pulverized coal scraping inlets are evenly distributed and opened through the pipe wall of the outer casing along its axial direction. The multiple rows of elastic scraper teeth and multiple rows of pulverized coal scraping inlets are all located on the outer casing at the position between the mounting base and the pulverized coal and stone inlets. The multiple rows of elastic scraper teeth and multiple rows of pulverized coal scraping inlets are arranged alternately and sequentially.

[0010] Furthermore, the elastic scraper teeth include a nitrile rubber tooth body, and an elastic steel sheet is embedded and fixed inside the nitrile rubber tooth body.

[0011] Furthermore, the directional pulse airflow nozzle has a trumpet-shaped design.

[0012] Furthermore, the drill pipe body is made of Φ60mm high-strength alloy pipe, and the outer casing is made of Φ85mm high-strength alloy pipe; the spacing between adjacent elastic scraper teeth in each row is 150mm, and the height of the elastic scraper teeth is 5mm; the spacing between adjacent pulverized coal inlets in each row is 150mm; the spacing between two adjacent sets of nozzles on the directional pulse airflow duct is 150mm.

[0013] Another aspect of the present invention provides a drilling method for preventing drill pipe blockage using the above-mentioned mechanical scraping-pulse airflow synergy, comprising the following steps:

[0014] S1. Equipment System Preparation and Connection

[0015] The equipment system includes anti-clogging drill rods, drilling rigs, explosion-proof air compressors for mining, explosion-proof booster pumps for mining, pulse airflow generators, explosion-proof solenoid valves, PLC controllers, and signal base stations;

[0016] The anti-clogging drill rod is mounted on the drilling rig via its mounting base. The mine explosion-proof air compressor is connected to the mine explosion-proof booster pump via pipeline. The mine explosion-proof booster pump is connected to the pulse airflow generator via pipeline. The pulse airflow generator is connected to the explosion-proof solenoid valve via pipeline. The explosion-proof solenoid valve is connected to the directional pulse airflow duct in the anti-clogging drill rod via pipeline and rotary joint. The mine explosion-proof air compressor, mine explosion-proof booster pump, pulse airflow generator, and explosion-proof solenoid valve are all connected to the PLC controller.

[0017] S2. Directional drilling construction

[0018] The pilot hole was constructed using an ultra-high pressure directional drilling rig.

[0019] S3. Gas-water mixed slag discharge

[0020] Set the air pressure to 0.5MPa and the water flow rate to 50L / min to clean the coal dust in the pilot hole, ensuring the hole is unobstructed and avoiding initial blockage; after drilling is completed, use compressed air to blow away any residual coal dust in the hole again, and check that there is no obvious collapse of the hole wall.

[0021] S4. Equipment system commissioning and preheating

[0022] Turn on the mine explosion-proof air compressor and mine explosion-proof pressurization pump, and simultaneously start the pulse airflow generator. Observe the airflow status on the anti-clogging drill rod to ensure that the directional pulse airflow nozzle sprays air evenly and without blockage.

[0023] S5. Calibrate the torque sensor

[0024] Start the PLC controller, manually rotate the anti-blocking drill rod, calibrate the torque sensor, and stabilize the torque display at the set value during idling.

[0025] S6. Cooperative Drilling

[0026] The anti-clogging drill rod is lowered into the pilot hole, the drilling rig is started, and the initial drilling parameters are set. When the anti-clogging drill rod rotates, the broken coal and gravel that the drill bit drops fall into the spiral guide groove on the drill rod body through the broken coal and gravel inlet and are discharged by rotation. At the same time, the elastic scraper teeth scrape off the pulverized coal adhering to the borehole wall in real time. The scraped pulverized coal falls into the spiral guide groove on the drill rod body through the scraped pulverized coal inlet. The pulsed airflow is intermittently sprayed through the directional pulsed airflow nozzle to avoid the pulverized coal from agglomerating.

[0027] S7. Intelligent Control

[0028] Pause for 1 minute every 10m of drilling to observe the slag discharge status at the borehole opening. If the slag discharge suddenly decreases or a "slag break" occurs, increase the pulse frequency and continue for a period of time before resuming drilling to ensure smooth discharge of pulverized coal.

[0029] S8. Collaborative Closure

[0030] After drilling is completed, maintain a stable pulse airflow, reduce the air pressure, and simultaneously reduce the pulse frequency, then slowly retract the drill bit. After retracting the drill bit, turn off the mine explosion-proof air compressor, mine explosion-proof pressurization pump, and pulse airflow generator. Use compressed air to blow away the spiral guide grooves and directional pulse airflow nozzles on the anti-clogging drill rod, replace the severely worn elastic scraper teeth, and lubricate and maintain the anti-clogging drill rod.

[0031] S9. Acceptance Assessment

[0032] Inspect the borehole wall condition to confirm there are no obvious collapse sections; count the number of times a single borehole is blocked; test the gas extraction concentration and flow rate, monitor continuously for 3-5 days, and after confirming that the concentration is stable and there is no significant decay, switch to normal extraction operation.

[0033] Furthermore, in step S1 above, the output pressure of the mine explosion-proof air compressor is 0.8~1.2MPa, and the exhaust volume is 1.2m³ / min; the adjustment frequency of the pulse airflow generator is 10~15Hz.

[0034] Furthermore, in step S2 above, the model of the ultra-high pressure directional drilling rig is ZDY4500L, and the diameter of the pilot hole is 95mm.

[0035] Furthermore, in step S3 above, the air pressure in the air-water mixing method is set to 0.5 MPa and the water flow rate is set to 50 L / min.

[0036] Furthermore, in step S4 above, after turning on the mine explosion-proof air compressor and the mine explosion-proof pressurization pump, the pressure is slowly adjusted to 0.8~1.0MPa; after starting the pulse airflow generator, the pulse frequency is set to 12Hz.

[0037] Furthermore, in step S7 above, the pulse frequency is increased to 15Hz and maintained for 30s.

[0038] Furthermore, in step S8 above, the air pressure is reduced to 0.8 MPa, the pulse frequency is reduced to 10 Hz, and the drill retraction speed is 0.5 m / min.

[0039] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0040] 1) Outstanding synergistic anti-blocking effect: The dual mechanism of "elastic scraping + pulse airflow" works together to solve the problem of pulverized coal blockage from both the hole wall cleaning and guide channel disturbance, greatly reducing the number of downtime and drilling withdrawals, ensuring continuous drilling construction, and the pulse airflow can prevent hole wall collapse and provide a smooth channel for gas extraction.

[0041] 2) Strong equipment adaptability: No need to modify existing mainstream drilling rigs, it can directly replace traditional auger drill rods, reducing initial equipment investment and facilitating rapid promotion and application.

[0042] 3) Good construction safety and economy: Through real-time torque monitoring and dynamic control, drill bit damage caused by excessive drilling torque is avoided, and the service life of drill bit is extended; pulse airflow energy consumption is lower than that of traditional continuous airflow, and the elastic scraper teeth can be reused, significantly reducing equipment maintenance and energy consumption costs.

[0043] 4) Convenient operation and maintenance: Parameter control is mainly based on automatic linkage, which can be mastered by ordinary operators after simple training, without the need for professional technicians; each unit is modularly designed, which facilitates step-by-step installation, maintenance and replacement, adapts to complex underground construction environments and improves operational reliability. Attached Figure Description

[0044] The accompanying drawings, which are provided to further illustrate the invention and form part of this application, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention.

[0045] Figure 1 This is a schematic diagram of the planar structure of the anti-clogging drill rod of the present invention.

[0046] Figure 2 This is a partial cross-sectional view of the three-dimensional structure of the anti-clogging drill rod of the present invention.

[0047] Figure 3 This is a schematic diagram of the equipment system connection in the drilling construction method of the present invention.

[0048] Figure 4 This is a partial cross-sectional schematic diagram of the anti-clogging drill rod of the present invention.

[0049] In the diagram: 1. Drill rod body; 2. Spiral guide groove; 3. Drill bit; 4. Explosion-proof air compressor for mining; 5. Explosion-proof pressurization pump for mining; 6. Pulse airflow generator; 7. Explosion-proof solenoid valve; 8. PLC controller; 9. Signal base station; 10. Torque sensor; 11. Directional pulse airflow duct; 12. Directional pulse airflow nozzle; 13. Outer sleeve; 14. Mounting base; 15. Coal and stone inlet; 16. Elastic scraper teeth; 17. Pulverized coal inlet; 18. Connecting column. Detailed Implementation

[0050] To enable those skilled in the art to better understand the present invention, the present invention will be further described clearly and completely below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. Example 1

[0051] like Figure 1 , Figure 2 and Figure 4As shown, this embodiment provides a mechanical scraping-pulse airflow synergistic anti-clogging drill rod, including a drill rod body 1, which is made of a Φ60mm high-strength alloy tube; multiple spiral guide grooves 2 are evenly distributed on the outer wall of the drill rod body 1 and are arranged along its axial direction; a drill bit 3 is provided at the head of the drill rod body 1; and a torque sensor 10 is provided on the outer wall of the drill rod body 1.

[0052] The drill pipe body 1 is internally embedded with a directional pulse airflow duct 11 that runs along its axis. Multiple sets of nozzles are evenly connected to the directional pulse airflow duct 11, with a spacing of 150 mm between adjacent sets of nozzles. Each set of nozzles includes four directional pulse airflow nozzles 12 that are evenly distributed radially along the directional pulse airflow duct 11. The directional pulse airflow nozzles 12 are flared in shape, and the nozzles of the directional pulse airflow nozzles 12 are all located on the outer wall of the drill pipe body 1.

[0053] The drill pipe body 1 is fitted with an outer sleeve 13, which is made of a high-strength alloy pipe with a diameter of 85mm. The outer sleeve 13 is coaxially connected and fixed to the drill pipe body 1. The outer sleeve 13 and the drill pipe body 1 can be connected and fixed through one or more connecting posts 18, and a gap is left between the outer sleeve 13 and the drill pipe body 1 to form a pulverized coal exit channel.

[0054] The outer casing 13 has a mounting base 14 fixedly connected to the outer wall near the tail end for connection and installation with the drilling rig. The outer casing 13 has multiple coal and stone inlets 15 evenly distributed and penetrated on the pipe wall near the head end.

[0055] Multiple rows (two, three, four, etc.) of elastic scraping teeth 16 are evenly distributed and fixed on the outer wall of the outer sleeve 13 along its axial direction. Each row includes multiple evenly distributed and spaced elastic scraping teeth 16 with a spacing of 150 mm between adjacent elastic scraping teeth 16 and a height of 5 mm for each elastic scraping tooth 16. Each elastic scraping tooth 16 includes a nitrile rubber tooth body, and an elastic steel sheet is embedded and fixed inside the nitrile rubber tooth body. The elastic steel sheet is fixedly connected to the outer wall of the outer sleeve 13.

[0056] Multiple rows (two, three, four, etc.) of scraping coal inlets 17 are evenly distributed and penetrated on the pipe wall of the outer sleeve 13 along its axial direction. Each row includes multiple evenly distributed scraping coal inlets 17 with a spacing of 150mm between adjacent scraping coal inlets 17.

[0057] The multi-row elastic slag scraper teeth 16 and the multi-row pulverized coal scraping inlet 17 are both set on the outer sleeve 13 at the position between the mounting base 14 and the crushed coal and stone inlet 15, and the multi-row elastic slag scraper teeth 16 and the multi-row pulverized coal scraping inlet 17 are arranged alternately in sequence. Example 2

[0058] This example uses the No. 25 coal seam in a deep, high-gas mine as an example. The seam is 1000m deep, with a ground stress of 32MPa, a pulverized coal content of 75%, and a permeability coefficient of 0.0005m² / (MPa²·d). When drilling with a traditional auger drill rod, each hole is blocked four times, resulting in numerous shutdowns, low hole formation rate, and poor gas extraction efficiency, which fails to meet the treatment requirements.

[0059] Therefore, this embodiment employs the anti-blocking drill pipe opening method with the combined mechanical scraping and pulsed airflow effect described in Embodiment 1 to perform drilling operations on the target coal seam, such as... Figure 3 As shown, the specific steps include the following:

[0060] S1. Equipment System Preparation and Connection

[0061] The equipment system includes anti-clogging drill rods, drilling rigs, mine explosion-proof air compressor 4, mine explosion-proof booster pump 5, pulse airflow generator 6, explosion-proof solenoid valve 7, PLC controller 8, and signal base station 9; among them, the output pressure of the mine explosion-proof air compressor 4 is 0.8~1.2MPa, and the exhaust volume is 1.2m³ / min; the adjustment frequency of the pulse airflow generator 6 is 10~15Hz.

[0062] The anti-clogging drill rod is mounted on the drilling rig via its mounting base 14. The mine explosion-proof air compressor 4 is connected to the mine explosion-proof booster pump 5 via pipeline. The mine explosion-proof booster pump 5 is connected to the pulse airflow generator 6 via pipeline. The pulse airflow generator 6 is connected to the explosion-proof solenoid valve 7 via pipeline. The explosion-proof solenoid valve 7 is connected to the directional pulse airflow duct 11 in the anti-clogging drill rod via pipeline and rotary joint. The mine explosion-proof air compressor 4, the mine explosion-proof booster pump 5, the pulse airflow generator 6, and the explosion-proof solenoid valve 7 are all connected to the PLC controller 8. The PLC controller 8 and the torque sensor 10 transmit signals through the signal base station 9.

[0063] S2. Directional drilling construction

[0064] The pilot hole was constructed using an ultra-high pressure directional drilling rig; the model of the ultra-high pressure directional drilling rig was ZDY4500L, and the diameter of the pilot hole was 95mm.

[0065] S3. Gas-water mixed slag discharge

[0066] Set the air pressure to 0.5MPa and the water flow rate to 50L / min to clean the coal dust in the pilot hole, ensuring the hole is unobstructed and avoiding initial blockage; after drilling is completed, use compressed air to blow away any residual coal dust in the hole again, and check that there is no obvious collapse of the hole wall.

[0067] S4. Equipment system commissioning and preheating

[0068] Turn on the mine explosion-proof air compressor 4 and the mine explosion-proof pressurization pump 5, and slowly adjust the pressure to 0.8~1.0MPa (in specific implementation, 0.8, 0.9, 1.0MPa, etc. can be selected); simultaneously start the pulse airflow generator 6 and set the pulse frequency to 12Hz; observe the airflow status on the anti-clogging drill rod to ensure that the directional pulse airflow nozzle 12 sprays air evenly and without blockage.

[0069] S5. Calibrate Torque Sensor 10

[0070] Start the PLC controller 8, manually rotate the anti-blocking drill rod, and calibrate the torque sensor 10 to stabilize the torque display at the set value during idling. In specific implementation, conventional early warning and over-limit function devices can be added to ensure that when the torque exceeds the early warning value, an audible and visual warning is issued, and the propulsion power is automatically cut off when the limit is exceeded.

[0071] S6. Cooperative Drilling

[0072] The anti-blocking drill rod is lowered into the pilot hole, the drilling rig is started, and the initial drilling parameters are set: advance speed 0.7 m / min and rotation speed 35 r / min. When the anti-blocking drill rod rotates, the crushed coal and gravel drilled by the drill bit 3 falls into the spiral guide groove 2 on the drill rod body 1 through the crushed coal and gravel inlet 15 and is discharged by rotation. At the same time, the elastic scraper teeth 16 scrape off the pulverized coal adhering to the borehole wall in real time. The scraped pulverized coal falls into the spiral guide groove 2 on the drill rod body 1 through the scraped pulverized coal inlet 17. The pulsed airflow is intermittently sprayed through the directional pulsed airflow nozzle 12 to avoid pulverized coal agglomeration.

[0073] S7. Intelligent Control

[0074] Pause for 1 minute every 10m of drilling to observe the slag discharge status at the borehole opening. If the slag discharge suddenly decreases or a "slag break" occurs, increase the pulse frequency to 15Hz and continue for 30s before resuming drilling to ensure smooth discharge of pulverized coal.

[0075] S8. Collaborative Closure

[0076] After drilling is completed, maintain a stable pulse airflow, reduce the air pressure to 0.8 MPa, and simultaneously reduce the pulse frequency to 10 Hz. Slowly retract the drill at a retraction speed of 0.5 m / min. After retraction, turn off the mine explosion-proof air compressor 4, the mine explosion-proof pressurization pump 5, and the pulse airflow generator 6. Use compressed air to blow away the spiral guide groove 2 and the directional pulse airflow nozzle 12 on the anti-clogging drill rod. Replace the severely worn elastic scraper teeth 16 and lubricate and maintain the anti-clogging drill rod.

[0077] S9. Acceptance Assessment

[0078] Inspect the borehole wall condition to confirm there are no obvious collapse sections; count the number of times a single borehole is blocked; test the gas extraction concentration and flow rate, monitor continuously for 3-5 days, and after confirming that the concentration is stable and there is no significant decay, switch to normal extraction operation.

[0079] In summary, the technical solution of this invention adopts a three-level linkage of "surface airflow supply unit - downhole self-cleaning drill pipe unit - intelligent monitoring and control unit".

[0080] The surface airflow supply unit mainly consists of a mine explosion-proof air compressor 4, a mine explosion-proof booster pump 5, and a pulse airflow generator 6, providing a stable and adjustable pulse airflow for borehole clogging prevention, thus avoiding the compaction and accumulation of pulverized coal. The mine explosion-proof air compressor 4 can be used for multiple borehole operations simultaneously; the pulse airflow generator 6 controls the airflow interruption through an electromagnetic valve, forming intermittent airflow to prevent continuous airflow from blowing pulverized coal to the bottom of the borehole for compaction.

[0081] The downhole self-cleaning drill pipe unit mainly consists of the drill pipe body 1 and its spiral guide groove 2, outer casing 13, elastic scraper teeth 16, directional pulse airflow duct 11, and directional pulse airflow nozzle 12. The elastic scraper teeth 16 remove pulverized coal in the borehole, and the directional pulse airflow nozzle 12 breaks up the "coal bridge". The elastic scraper teeth 16 are made of nitrile rubber with embedded elastic steel sheets, which can adapt to borehole wall deformation, reduce blind spots, and remove pulverized coal adhering to the borehole wall in real time and let it fall into the pulverized coal inlet 17 on the outer casing 13. The directional pulse airflow nozzle 12 on the directional pulse airflow duct 11 faces the direction of coal slag discharge and is trumpet-shaped, used to break up the "coal bridge" formed by the pulverized coal agglomeration accumulated on the drill pipe body 1.

[0082] The intelligent monitoring and control unit mainly consists of a torque monitoring component, a control core, and a remote monitoring module. The torque monitoring component is mainly a torque sensor 10, which is integrated on the drill pipe body 1. The torque sensor 10 is a mining explosion-proof torque sensor that collects drilling torque data in real time. The control core is mainly a PLC controller, which adopts an industrial-grade dual-core PLC controller. It uses a remote control algorithm to set warning values ​​and over-limit values ​​for torque and pressure. When a warning is issued, the pulse airflow parameters are automatically adjusted. If the limit is exceeded, the drilling rig's propulsion power is cut off. The remote monitoring module uses conventional equipment in this field and realizes data visualization management through a display, showing torque, airflow pressure, and frequency in real time, which makes it easy for operators to intuitively grasp the working conditions.

[0083] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A mechanical scraping-pulse air flow synergistic anti-clogging drill rod, comprising a drill rod body (1), a plurality of helical guide grooves (2) are uniformly arranged on the outer wall of the drill rod body (1) and longitudinally arranged along the axial direction of the drill rod body (1), and a drill bit (3) is arranged at the head of the drill rod body (1); characterized in that: A torque sensor (10) is provided on the outer wall of the drill pipe body (1); a directional pulse airflow duct (11) is embedded inside the drill pipe body (1) and runs along its axis. Multiple sets of nozzles are evenly connected on the directional pulse airflow duct (11). Each set of nozzles includes multiple directional pulse airflow nozzles (12) evenly distributed in the radial direction. The nozzle of each directional pulse airflow nozzle (12) is opened on the outer wall of the drill pipe body (1). ​ An outer sleeve (13) is fitted around the drill pipe body (1). The outer sleeve (13) is coaxially connected and fixed to the drill pipe body (1). A gap is left between the outer sleeve (13) and the drill pipe body (1) to form a coal discharge channel. A mounting base (14) for connecting and installing with the drilling rig is fixedly connected to the outer wall of the outer sleeve (13) near the tail end. Multiple coal and stone inlets (15) are evenly distributed and penetrated on the pipe wall of the outer sleeve (13) near the head end. The cloth is fixed with multiple rows of elastic scraper teeth (16) arranged along its axis. Multiple rows of pulverized coal scraping inlets (17) are evenly distributed and opened on the pipe wall of the outer sleeve (13) along its axis. The multiple rows of elastic scraper teeth (16) and multiple rows of pulverized coal scraping inlets (17) are all located on the outer sleeve (13) between the mounting base (14) and the crushed coal and stone inlet (15). The multiple rows of elastic scraper teeth (16) and multiple rows of pulverized coal scraping inlets (17) are arranged alternately in sequence.

2. A mechanical scraping-pulsed air flow synergic anti-plugging drill rod according to claim 1, characterized in that: The elastic scraper tooth (16) includes a nitrile rubber tooth body, and an elastic steel sheet is embedded and fixed inside the nitrile rubber tooth body.

3. A mechanical scraping-pulsed air flow synergic anti-plugging drill rod according to claim 1, characterized in that: The directional pulse airflow nozzle (12) has a trumpet-shaped shape.

4. A mechanical scraping-pulsed air flow synergic anti-plugging drill rod according to claim 1, characterized in that: The drill pipe body (1) is made of Φ60mm high-strength alloy pipe, and the outer casing (13) is made of Φ85mm high-strength alloy pipe; the spacing between adjacent elastic scraper teeth (16) in each row is 150mm, and the height of the elastic scraper teeth (16) is 5mm; the spacing between adjacent pulverized coal inlets (17) in each row is 150mm; the spacing between two adjacent sets of nozzles on the directional pulse airflow duct (11) is 150mm.

5. A method of drilling operation for preventing the plugging of a drill pipe by mechanically scraping and synergistically acting with the pulse air flow as claimed in claim 1, wherein Includes the following steps: S1. Equipment System Preparation and Connection The equipment system includes anti-blocking drill rod, drilling rig, mine explosion-proof air compressor (4), mine explosion-proof booster pump (5), pulse airflow generator (6), explosion-proof solenoid valve (7), PLC controller (8) and signal base station (9); The anti-blocking drill rod is installed on the drilling rig via the mounting base (14) on it. The mine explosion-proof air compressor (4) is connected to the mine explosion-proof booster pump (5) via pipeline. The mine explosion-proof booster pump (5) is connected to the pulse airflow generator (6) via pipeline. The pulse airflow generator (6) is connected to the explosion-proof solenoid valve (7) via pipeline. The explosion-proof solenoid valve (7) is connected to the directional pulse airflow duct (11) in the anti-blocking drill rod via pipeline and rotary joint. The mine explosion-proof air compressor (4), the mine explosion-proof booster pump (5), the pulse airflow generator (6), and the explosion-proof solenoid valve (7) are all connected to the PLC controller (8). S2. Directional drilling construction The pilot hole was constructed using an ultra-high pressure directional drilling rig; S3. Gas-water mixed slag discharge Set the air pressure to 0.5MPa and the water flow rate to 50L / min to clean the coal dust in the pilot hole, ensuring the hole is unobstructed and avoiding initial blockage; after drilling is completed, use compressed air to blow away any residual coal dust in the hole again, and check that there is no obvious collapse of the hole wall; S4. Equipment system commissioning and preheating Turn on the mine explosion-proof air compressor (4) and the mine explosion-proof pressurizing pump (5), and simultaneously start the pulse airflow generator (6). Observe the air jet status on the anti-blocking drill rod to ensure that the directional pulse airflow nozzle (12) sprays air evenly and without blockage. S5. Calibrate the torque sensor Start the PLC controller (8), manually rotate the anti-blocking drill rod, calibrate the torque sensor (10), and make the torque display in the idling state stable at the set value; S6. Cooperative Drilling The anti-blocking drill rod is lowered into the pilot hole, the drilling machine is started, and the initial drilling parameters are set. When the anti-blocking drill rod rotates, the broken coal and gravel that the drill bit (3) drills down fall into the spiral guide groove (2) on the drill rod body (1) through the broken coal and gravel inlet (15) and are rotated out. At the same time, the elastic scraper teeth (16) scrape off the coal adhering to the hole wall in real time. The scraped coal falls into the spiral guide groove (2) on the drill rod body (1) through the scraped coal inlet (17). The pulse airflow is intermittently sprayed through the directional pulse airflow nozzle (12) to avoid coal agglomeration. S7. Intelligent Control Pause for 1 minute every 10m of drilling to observe the slag discharge status at the borehole opening. If the slag discharge volume decreases suddenly or a "slag break" occurs, increase the pulse frequency and continue for a period of time before resuming drilling to ensure smooth discharge of pulverized coal. S8. Collaborative Closure After drilling is completed, maintain stable pulse airflow, reduce air pressure, reduce pulse frequency simultaneously, and slowly withdraw the drill; after withdrawal, shut down the mine explosion-proof air compressor (4), mine explosion-proof pressurizing pump (5) and pulse airflow generator (6), use compressed air to blow away the spiral guide groove (2) and directional pulse airflow nozzle (12) on the anti-blocking drill rod, and maintain the anti-blocking drill rod; S9. Acceptance Assessment Inspect the borehole wall condition to confirm there are no obvious collapse sections; count the number of times a single borehole is blocked; test the gas extraction concentration and flow rate, monitor continuously for 3-5 days, and after confirming that the concentration is stable and there is no significant decay, switch to normal extraction operation.

6. A method of drilling with a mechanical scraping-pulsed air flow synergy anti-plugging drill rod according to claim 5, characterized in that: In step S1, the output pressure of the mine explosion-proof air compressor (4) is 0.8~1.2MPa and the exhaust volume is 1.2m³ / min; the adjustment frequency of the pulse airflow generator (6) is 10~15Hz.

7. A method of drilling with a mechanical scraping-pulsed air flow synergistic anti- clogging drill rod according to claim 5, characterized in that: In step S2, the drilling rig model is ZDY4500L, and the diameter of the pilot hole is 95mm.

8. The drilling method for preventing drill rod blockage by mechanical scraping and pulsed airflow synergy as described in claim 5, characterized in that: In step S4, after turning on the mine explosion-proof air compressor (4) and the mine explosion-proof pressurizing pump (5), the pressure is slowly adjusted to 0.8~1.0MPa; after starting the pulse airflow generator (6), the pulse frequency is set to 12Hz.

9. The drilling method for preventing drill rod blockage by mechanical scraping and pulsed airflow synergy as described in claim 5, characterized in that: In step S7, the pulse frequency is increased to 15Hz and held for 30s.

10. The drilling method for preventing drill rod blockage by mechanical scraping and pulsed airflow synergy according to claim 5, characterized in that: In step S8, the air pressure is reduced to 0.8 MPa, the pulse frequency is reduced to 10 Hz, and the drill retraction speed is 0.5 m / min.

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