Air jet flow punching operation device capable of achieving mine pressure and air pressure self-pressurization and operation method

Abstract

The invention belongs to the technical field of coal mine gas control and coal bed gas development, and particularly relates to an air jet flow punching operation device capable of achieving mine pressure and wind pressure self-pressurization and an operation method, the air jet flow punching operation device comprises a gas source pipeline and a water source pipeline, and the gas source pipeline and the water source pipeline are communicated with the interior of a drill rod through a gas tail inlet; the front end of the drill rod is connected with an air jet puncher, and the front end of the air jet puncher is connected with a drill bit; the air jet puncher is provided with an inner-layer pipeline and an outer-layer pipeline, self-pressurization assemblies are arranged at the upper and lower symmetrical positions in the outer-layer pipeline respectively, each self-pressurization assembly comprises a micro screw air compressor and an air flow channel, and a damping turbofan and a Laval nozzle are arranged in each air flow channel. The damping turbofan is arranged at the tail end of a driving shaft of the micro screw air compressor, an air inlet of the micro screw air compressor is connected with the inner-layer pipeline through an air flow channel, and an exhaust port of the micro screw air compressor is communicated with the outside through the air flow channel; two fixing blocks are symmetrically arranged on the inner wall of the inner-layer pipeline up and down, each fixing block is provided with a spring, a sliding block is arranged at the end of each spring, and the sliding blocks block an air flow channel opening where the damping turbofan is located and an air inlet of the miniature screw air compressor when the springs are in a natural state; according to the device, self-pressurization of air in the drill rod can be realized based on a built-in miniature screw air compressor of the air jet puncher, so that the coal crushing efficiency of air jet is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mine gas control and coal bed methane development, and in particular relates to an air jet punching operation device and an operation method capable of realizing self-pressurization of mine pressure and wind pressure. Background Art

[0002] At present, the technical measures for coal seam permeability enhancement and enhanced gas extraction adopted by most coal mines in my country are hydraulic punching technology. However, due to problems such as uneven coal unloading and poor slag discharge during hydraulic punching, coal slag, water and gas will accumulate in the borehole, resulting in "hole spraying" and "drill sticking" phenomena, leading to excessive gas in the tunnel and loss of drilling tools. Moreover, after the coal body around the borehole is soaked in water, the fluidity of the coal body is enhanced, resulting in extremely unstable spatial structure of punching pressure relief, easy collapse of the borehole, difficulty in lowering the screen pipe, and easy generation of stress concentration zones.

[0003] In order to solve various problems in hydraulic punching technology, air jet punching is used to dehydrate the coal seam, relieve pressure and increase permeability. Air jet punching constructs a stable pressure relief space in the borehole, and the slag discharge is smooth during the punching process, and the "water lock effect" is avoided, which can effectively improve the punching effect. Wind pressure can affect the coal output and punching radius during air jet punching operation. Appropriately increasing wind pressure can effectively improve the efficiency of air jet punching. Using the device and method proposed in the present invention, the wind pressure under the mine can be self-pressurized. Summary of the invention

[0004] The purpose of the present invention is to provide an air jet punching operation device and operation method that can realize self-pressurization of mine pressure and wind pressure. On the basis of traditional punching equipment, the present invention changes hydraulic punching into air jet punching, and installs an air jet puncher between the drill rod and the drill bit. The device can realize self-pressurization of the air in the drill rod based on the built-in micro screw air compressor of the air jet puncher, thereby improving the crushing efficiency of the air jet on the coal body.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] An air jet punching device capable of realizing self-pressurization of wind pressure in a mine comprises an air source pipeline and a water source pipeline, the air source pipeline and the water source pipeline are respectively connected through an air tail inlet and the inside of a drill pipe, an air jet puncher is connected to the front end of the drill pipe, and a drill bit is connected to the front end of the air jet puncher; the air jet puncher is provided with an inner layer pipeline and an outer layer pipeline, a self-pressurization component is respectively provided at an upper and lower symmetrical position inside the outer layer pipeline, each self-pressurization component comprises a micro screw air compressor and a wind channel, and the wind A damping turbofan and a Rafael nozzle are provided in the flow channel, the damping turbofan is arranged at the end of the driving shaft of the micro screw air compressor, the air inlet of the micro screw air compressor is connected with the inner pipeline through the wind flow channel, and the exhaust port of the micro screw air compressor is connected with the outside through the wind flow channel; two fixed blocks are symmetrically provided on the upper and lower inner walls of the inner pipeline, each fixed block is provided with a spring, and a slider is provided at the end of the spring, and the slider blocks the wind flow channel opening where the damping turbofan is located and the air inlet of the micro screw air compressor when the spring is in a natural state.

[0007] Furthermore, the airflow channel includes airflow channel one, airflow channel two, airflow channel three and airflow channel four. Airflow channel one is connected to the air inlet of the micro screw air compressor. The damping turbofan is located in airflow channel four. Airflow channel one and airflow channel four are connected to the inner pipeline when the spring is in a compressed state. Each slider blocks airflow channel one and airflow channel four when the spring is in a natural state. Airflow channel three is connected to the exhaust port of the micro screw air compressor and is provided with a Rafale nozzle at the end and is connected to the outside. The airflow channel two is connected to the exhaust port of the damping turbofan and the other end is connected to the outside.

[0008] Furthermore, it also includes a steel ball, the outer diameter of the steel ball matches the inner diameter of the drill rod, and the inner diameter of the drill rod is connected to the internal pipeline of the air jet puncher and has the same diameter.

[0009] Furthermore, the sliding block inside the air jet puncher is a hollow cylinder, the outer diameter of which matches the inner pipeline of the air jet puncher, and a gap is provided between the two fixing blocks.

[0010] Furthermore, the outer layer pipeline is also provided with an air volume adjustment channel, the air volume adjustment channel is connected with the wind flow channel and a blocking bolt is provided inside.

[0011] Furthermore, the micro screw air compressor is provided with a sealed shell on the outside, and an active screw and a passive screw that mesh with each other are provided inside the sealed shell. The active screw is sleeved on the drive shaft, and the passive screw is movably arranged in the sealed shell. The active screw and the passive screw are provided with mutually meshing teeth outside.

[0012] Furthermore, the drill rod and the air jet puncher are respectively provided with internal threads and external threads at both ends, the drill bit is provided with an internal pipeline, and the drill bit surface is provided with a nozzle; the air source pipeline includes an air pressure pump, an air storage tank connected to the air pressure pump, a valve and a pressure gauge are provided on the air storage tank outlet pipeline, and the gas outlet pipeline is connected to the gas tail inlet; the water source pipeline includes a water tank, a high-pressure water pump connected to the water tank outlet, the high-pressure water pump outlet pipeline is connected to the gas tail inlet, and a valve and a pressure gauge are also provided on the water tank outlet pipeline.

[0013] An air jet punching operation method with self-pressurized wind pressure in underground mines, comprising the following steps:

[0014] S1. Add water to the water tank, connect the high-pressure water pump to the air tail inlet with a high-pressure hose, connect the air tail to the internal passage of the drill pipe, and install the air jet puncher between the drill bit and the drill pipe. Turn on the high-pressure water pump and the directional drilling rig, set the water pressure to 0.5MPa to start drilling. The water flows through the internal passage of the drill pipe and the middle passage of the inner layer of the air jet puncher. Finally, the water flows to the inside of the drill bit and is sprayed out through the drill bit nozzle to reduce temperature and dust.

[0015] S2. After drilling is completed, turn off the directional drill and the high-pressure water pump, disconnect the high-pressure water pump and the air tail, and allow the remaining water inside the drill pipe and the inner layer pipeline of the air jet punch to flow out;

[0016] S3. When no water flows out, put the steel ball into the gas tail inlet, connect the air pressure pump to the gas tail inlet with a high-pressure hose, turn on the air pressure pump, and when the gas pressure in the tank reaches 5MPa, open the valve, and let high-pressure air into the inner drill pipe. The air release pressure is controlled to be 1MPa through the pressure gauge. The high-pressure gas is connected to the inside of the drill pipe from the gas tail inlet. The high-pressure gas reaches the inner pipeline of the air jet punch through the internal passage of the drill pipe and brings the steel ball to the inner pipeline of the air jet punch. When the steel ball hits the slider of the inner pipeline, the spring contracts the steel ball to drive the slider forward. After the slider moves, the gas and the outer pipe The wind flow channel 1 and the wind flow channel 4 in the middle of the road are connected. A part of the gas drives the damping turbofan to rotate through the wind flow channel 4, and the damping turbofan drives the driving shaft to rotate to make the micro screw air compressor work. The gas wind flow channel 2 after passing through the damping turbofan is discharged to the outside of the air jet puncher and used for slag removal; the other part of the gas reaches the air inlet of the micro screw air compressor through the wind flow channel 1 to make the screw air compressor work. The gas enters the closed space formed between the tooth groove and the sealing shell, and the gas inside is compressed. The compressed gas is discharged from the exhaust port of the micro screw air compressor, and finally reaches the Rafale nozzle along the wind flow channel 3, and is accelerated and ejected by the Rafale nozzle;

[0017] S4. The directional drill drives the drill rod and the air jet puncher to rotate and gradually withdraw from the borehole. The self-pressurized air jet is ejected from the air jet puncher to destroy the coal body, thereby performing the punching operation;

[0018] S5. After the punching operation is completed, the air pump is turned off, the steel ball slides out of the drill pipe, and the drill pipe, the air jet puncher and the drill bit are withdrawn. At this time, the slider moves backward under the action of the spring, and the air flow channel 1 and the air flow channel 4 in the outer pipeline are blocked again;

[0019] S6. Adjust the angle of the directional drill and repeat steps S1-S5 at the new drilling location to perform the punching operation at the new drilling location.

[0020] The advantages of the present invention are:

[0021] 1. The present invention adopts air jet instead of traditional hydraulic punching, which can build a relatively stable pressure relief space in the borehole during punching, thereby avoiding hole collapse and improving punching operation efficiency. The water-free punching operation mode can avoid the water lock effect, thereby improving the gas extraction efficiency after punching;

[0022] 2. The present invention can realize the self-pressurization of the wind pressure under the mine, thereby improving the efficiency of air jet coal breaking, which is more economical than the traditional method;

[0023] 3. The present invention can perform integrated drilling and punching operations on the coal body. After drilling is completed, punching operations can be performed without withdrawing the drill, thereby improving operation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is an overall schematic diagram of the punching operation device of the present invention.

[0025] Figure 2 It is a schematic diagram of the structure of the air jet puncher in the present invention.

[0026] Figure 3 It is a schematic diagram of the structure of the micro screw air compressor in the air jet puncher of the present invention.

[0027] Figure 4 It is a schematic diagram of the drill rod structure in the present invention.

[0028] Figure 5 It is a schematic diagram of the sealing bolt in the present invention. DETAILED DESCRIPTION

[0029] Example

[0030] like Figure 1-5As shown, an air jet punching device capable of realizing self-pressurization of wind pressure under a mine comprises an air jet puncher 10, a drill bit 11, a directional drill 9, a drill rod 8, an air tail 5, an air pressure pump 1, a high-pressure gas storage tank 2, a valve 3, a pressure gauge 4, a water tank 6, and a high-pressure water pump 7. The drill rod 8 has an internal thread 29 at one end and an external thread 30 at the other end. When in use, multiple connections can be selected as needed. The air jet puncher is installed at the front end of the drill rod through threads, and the drill bit 11 is installed at the front end of the air jet puncher through threads. The drill bit has an internal pipeline for water flow, and a nozzle is provided at the front end of the drill bit for spraying water to cool down and reduce dust during drilling.

[0031] The air jet puncher 10 mainly includes an inner pipeline and an outer pipeline. The inner pipeline is connected to the internal passage of the drill pipe and has the same diameter. The outer pipeline contains a micro screw air compressor 17, a micro screw air compressor drive shaft 22, a damping turbofan 23, a Rafale nozzle 20, an air volume adjustment channel 12, an air flow channel 1 14, an air flow channel 2 15, an air flow channel 3 19 and an air flow channel 4 21. The air flow channel 1 14 is connected to the air inlet 16 of the screw air compressor. Before operation, the area of ​​the air flow channel 1 can be adjusted through an inner tube from the air volume adjustment channel according to different working conditions, so as to adjust the air intake of the screw air compressor. After adjustment, the air volume adjustment channel is blocked by a blocking bolt 13. The damping turbofan 23 and the micro screw air compressor drive shaft 22 are in the air flow channel 4 21. The damping turbofan is installed on the end of the micro screw air compressor drive shaft. When the damping turbofan is installed on the end of the micro screw air compressor drive shaft, When the Ni turbofan rotates, it can drive the drive shaft of the micro screw air compressor to rotate, so that the micro screw air compressor 17 starts to work. The Rafale nozzle 20 is connected to the exhaust port 18 of the screw air compressor through the wind channel three 19 and communicates with the outside. Except for the micro screw air compressor and each channel, the rest of the outer pipeline is solid; two fixed blocks 26 are symmetrically arranged on the inner wall of the inner pipeline, each fixed block is provided with a spring 25, and a slider 24 is provided at the end of the spring. The middle of the two sliders is a central passage. The slider is a hollow cylinder, and its outer diameter matches the inner pipeline of the air jet puncher. The outside of the two sliders is the wind channel 14 and the wind channel 4 21 of the outer pipeline. When the spring is in a natural state, the slider can block the wind channel 14 and the wind channel 4 21. When the slider moves, the spring is deformed, so that the inner pipeline can communicate with the external wind channel 14 and the wind channel 4 21.

[0032] During drilling operation, the high-pressure water pump 7 is connected to the drill rod 8 through the air tail inlet 5, and the high-pressure water flows through the air jet punch 10 from the internal passage of the drill rod. At this time, the water pressure is relatively small and will not cause the slider 24 to move. The water finally reaches the inside of the drill bit 11 through the middle passage of the inner layer pipeline of the air jet punch, and the water is sprayed out from the nozzle at the front end of the drill bit to cool down and reduce dust during drilling.

[0033] When punching, put the steel ball into the tail gas inlet 5, the air pressure pump 1 is connected to the drill pipe 8 through the tail gas inlet, and the high-pressure gas brings the steel ball to the inner pipeline of the air jet puncher 10. When the steel ball hits the slider 24 of the inner pipeline, the spring 25 contracts, and the steel ball drives the slider to move backward and close to the fixed block 26. After the slider moves, the high-pressure gas is connected with the air flow channel 1 14 and the air flow channel 4 21 in the outer pipeline. The gas passes through the air flow channel 4, driving the damping turbofan 23 to rotate, and the damping turbofan drives the micro screw air compressor drive shaft 22 to rotate, so that the micro screw air compressor 17 works, and the gas after passing through the damping turbofan can flow through the air flow thereafter. Channel 2 15 is discharged to the outside of the air jet puncher, directly to the inside of the drill hole and used for slag removal; the gas reaches the screw air compressor air inlet 16 through the wind flow channel 14, the screw air compressor air inlet is opened, and the gas enters the screw air compressor. At this time, the high-pressure air in the inner pipeline makes the screw air compressor work, and the gas enters the enclosed space formed between the screw tooth groove and the screw air compressor sealing shell 27. As the screw 28 rotates, the volume of the enclosed space formed between the screw tooth groove and the screw air compressor sealing shell gradually decreases, thereby compressing the gas therein. The compressed gas is discharged from the screw air compressor exhaust port 18, and finally reaches the Rafale nozzle 20 along the wind flow channel, and is accelerated and ejected by the Rafale nozzle.

[0034] Material balance of screw air compressor in drill pipe:

[0035] Gas flow after entering the drill pipe:

[0036] Q=v×πr 2 Where Q is the gas flow rate; r is the radius of the internal passage of the drill pipe, which is 2 cm; v is the gas flow rate, and v is 8 m / s.

[0037] The gas flow rate entering the air inlet of the screw air compressor is:

[0038]

[0039] In the formula, Q 2 is the gas flow rate entering a screw air compressor; A 1 A is the cross-sectional area of ​​the airflow channel after adjustment by the inner insert tube; 2 is the cross-sectional area of ​​the air flow channel, which is 3.14 cm 2 .

[0040] Adjust the air flow channel 1 so that its cross-sectional area is 0.0314cm 2 , then we can calculate Q 2 0.0029m 3 / min. The air intake flow rate of a normal screw air compressor, which is about 10 times the size of the micro screw air compressor in the present invention, is about 2.5m 3 / min, its volume is about 1000 times that of the micro screw air compressor. If calculated proportionally, when the volume of the screw air compressor is reduced by 1000 times, its intake flow rate is 0.0025m 3 / min, Q 2 0.0029m 3 / min, the difference between the two is small, and the cross-sectional area of ​​the air flow channel is adjusted to make Q 2 When the air flow rate of air flow channel 4 is reduced, the air flow rate of air flow channel 4 increases, which can increase the speed of the screw air compressor. The speed increase can increase the air flow rate that the screw air compressor can withstand, so at this time Q 2 The pressure boosting requirements of screw air compressors are met. In actual operation, due to limitations such as leakage, suction resistance, and rotation speed, when the volume of the screw air compressor increases, its intake flow rate cannot increase proportionally. Therefore, the intake flow rate that the micro screw air compressor in the present invention can withstand is much greater than 0.0025m 3 / min, so the area of ​​the air flow channel can be adjusted according to different working conditions during operation to flexibly adjust the air intake flow of the screw air compressor.

[0041] The compression process in the screw air compressor is very fast, and its compression process is close to the adiabatic compression process. The gas pressure at the exhaust port of the screw air compressor can be calculated as follows:

[0042]

[0043] Where P 1 P is the gas pressure at the inlet of the screw air compressor; 2 V is the gas pressure at the exhaust port of the screw air compressor; 1 V is the air intake volume of the screw air compressor; 2 is the exhaust volume of the screw air compressor; k is the air adiabatic index, which is 1.4;

[0044] The compression ratio of a screw compressor has no direct relationship with the size of the screw compressor. It mainly depends on the pitch and tooth design of the screw. 1 / V 2 is 3:1, P 1 When it is 1MPa, P can be calculated 2 It is 4.66MPa.

[0045] The formula for calculating the gas velocity after acceleration by the Lafarge nozzle is as follows:

[0046]

[0047] Where P e is the gas pressure at the outlet of the Lafayette nozzle; P 0 is the gas pressure at the inlet of the Lafayette nozzle, P 0 =P 2 ; Ma is the exit Mach number of the Lafayette nozzle.

[0048] P 0 is 4.66MPa. When the expansion ratio of the Lafayette nozzle is constant, the gas pressure at the gas outlet is also constant. If a Lafayette nozzle with an expansion ratio of 1.12 is used, then P e The device and method of the present invention can accelerate air to an ultra-high-speed air jet of more than Mach 2, which can effectively destroy the coal body, thereby performing air jet punching operations.

[0049] The relevant calculations for the inner pipeline slider of the air jet punch are as follows:

[0050] Ignoring the loss and friction along the way, calculate the gas pressure during punching:

[0051]

[0052] Where P 3 is the gas pressure that can move the slider during punching; r 2 is the radius of the steel ball, 2cm; m 1 is the mass of the steel ball, 270g; m 2 is the mass of the slider, which is 200g; k 2 is the spring stiffness coefficient, which is 12500N / m; x is the spring contraction distance.

[0053] When the spring contracts by 4.5 cm, the gas in the inner pipe can completely enter the airflow channel 1 and airflow channel 4. When x is 4.5 cm, P can be calculated. 3 It is 0.9MPa, that is, when the gas pressure is greater than 0.9MPa during punching, the gas in the inner pipeline can completely enter the airflow channel one and the airflow channel four.

[0054] Calculate the water pressure when drilling:

[0055]

[0056] Where P 4 A is the water pressure during drilling; 3 is the lateral area of ​​the slider on which the water flows, which is 3.14 cm 2 .

[0057] When the spring contracts less than 1.4 cm, the airflow channel 4 is still blocked by the slider. When x is 1.4 cm, P can be calculated. 4 It is 0.56MPa, that is, when the water pressure is less than 0.56MPa during drilling, the airflow channel 1 and the airflow channel 4 are still blocked by the slider, and the water flow in the inner pipeline cannot enter.

Claims

1. An air jet punching device capable of realizing self-pressurization of wind pressure under a mine, comprising an air source pipeline and a water source pipeline, wherein the air source pipeline and the water source pipeline are respectively connected to the inside of a drill pipe through an air tail inlet, an air jet puncher is connected to the front end of the drill pipe, and a drill bit is connected to the front end of the air jet puncher; characterized in that: The air jet puncher is provided with an inner layer pipeline and an outer layer pipeline, and a self-pressurizing component is respectively provided at an upper and lower symmetrical position inside the outer layer pipeline, each self-pressurizing component includes a micro screw air compressor and an airflow channel, and a damping turbofan and a Rafale nozzle are provided in the airflow channel. The damping turbofan is arranged at the end of the driving shaft of the micro screw air compressor, and the air inlet of the micro screw air compressor is connected to the inner layer pipeline through the airflow channel, and the exhaust port of the micro screw air compressor is connected to the outside through the airflow channel; two fixed blocks are symmetrically provided on the inner wall of the inner layer pipeline, and a spring is provided on each fixed block, and a slider is provided at the end of the spring, and when the spring is in a natural state, the slider blocks the airflow channel opening where the damping turbofan is located and the air inlet of the micro screw air compressor.

2. The air jet punching device capable of realizing self-pressurization of wind pressure under a mine as claimed in claim 1, characterized in that: The airflow channel includes airflow channel one, airflow channel two, airflow channel three and airflow channel four. Airflow channel one is connected to the air inlet of the micro screw air compressor. The damping turbofan is located in airflow channel four. Airflow channel one and airflow channel four are connected to the inner pipeline when the spring is in a compressed state. Each slider blocks airflow channel one and airflow channel four when the spring is in a natural state. Airflow channel three is connected to the exhaust port of the micro screw air compressor and is provided with a Rafale nozzle at the end and is connected to the outside. The airflow channel two is connected to the exhaust port of the damping turbofan and the other end is connected to the outside.

3. The air jet punching device capable of realizing self-pressurization of wind pressure under the mine as claimed in claim 1, characterized in that: It also comprises a small steel ball, the outer diameter of which matches the inner diameter of a drill rod, and the inner diameter of the drill rod is connected to an internal pipeline of the air jet puncher and has the same diameter.

4. The air jet punching device capable of realizing self-pressurization of wind pressure under a mine as claimed in claim 1, characterized in that: The sliding block inside the air jet punch is a hollow cylinder, the outer diameter of which matches the inner pipeline of the air jet punch, and a gap is provided between the two fixing blocks.

5. The air jet punching device capable of realizing self-pressurization of wind pressure under a mine as claimed in claim 1, characterized in that: The outer layer pipeline is also provided with an air volume adjustment channel, which is connected with the wind flow channel and has a blocking bolt inside.

6. The air jet punching device capable of realizing self-pressurization of wind pressure under a mine as claimed in claim 1, characterized in that: The micro screw air compressor is provided with a sealed shell on the outside, and an active screw and a passive screw that mesh with each other are provided inside the sealed shell. The active screw is sleeved on the driving shaft, and the passive screw is movably arranged in the sealed shell. The active screw and the passive screw are both provided with meshing teeth outside.

7. The air jet punching device capable of realizing self-pressurization of wind pressure under a mine as claimed in claim 1, characterized in that: The drill rod and the air jet puncher are respectively provided with internal threads and external threads at both ends, the drill bit is provided with an internal pipeline, and the drill bit surface is provided with a nozzle; the air source pipeline includes an air pressure pump, an air storage tank connected to the air pressure pump, a valve and a pressure gauge are provided on the air storage tank outlet pipeline, and the gas outlet pipeline is connected to the gas tail inlet; the water source pipeline includes a water tank, a high-pressure water pump connected to the water tank outlet, the high-pressure water pump outlet pipeline is connected to the gas tail inlet, and a valve and a pressure gauge are also provided on the water tank outlet pipeline.

8. The method for air jet punching operation under mine with wind pressure self-pressurization of the device according to any one of claims 1 to 7 comprises the following steps: S1. Add water to the water tank, connect the high-pressure water pump to the air tail inlet with a high-pressure hose, connect the air tail to the internal passage of the drill pipe, and install the air jet puncher between the drill bit and the drill pipe. Turn on the high-pressure water pump and the directional drilling rig, set the water pressure to 0.5MPa to start drilling. The water flows through the internal passage of the drill pipe and the middle passage of the inner layer of the air jet puncher. Finally, the water flows to the inside of the drill bit and is sprayed out through the drill bit nozzle to reduce temperature and dust. S2. After drilling is completed, turn off the directional drill and the high-pressure water pump, disconnect the high-pressure water pump and the air tail, and allow the remaining water inside the drill pipe and the inner layer pipeline of the air jet punch to flow out; S3. When no water flows out, put the steel ball into the gas tail inlet, connect the air pressure pump to the gas tail inlet with a high-pressure hose, turn on the air pressure pump, and when the gas pressure in the tank reaches 5MPa, open the valve, and let high-pressure air into the inner drill pipe. The air release pressure is controlled to be 1MPa through the pressure gauge. The high-pressure gas is connected to the inside of the drill pipe from the gas tail inlet. The high-pressure gas reaches the inner pipeline of the air jet punch through the internal passage of the drill pipe and brings the steel ball to the inner pipeline of the air jet punch. When the steel ball hits the slider of the inner pipeline, the spring contracts the steel ball to drive the slider forward. After the slider moves, the gas and the wind flow channel in the outer pipeline are connected. The first is connected with the air flow channel four, a part of the gas drives the damping turbofan to rotate through the air flow channel four, the damping turbofan drives the driving shaft to rotate to make the micro screw air compressor work, and the gas air flow channel two after passing through the damping turbofan is discharged to the outside of the air jet puncher and used for slag removal; the other part of the gas reaches the air inlet of the micro screw air compressor through the air flow channel one to make the screw air compressor work, the gas enters the closed space formed between the tooth groove and the sealing shell, and the gas inside is compressed. The compressed gas is discharged from the exhaust port of the micro screw air compressor, and finally reaches the Rafale nozzle along the air flow channel three, and is accelerated and ejected by the Rafale nozzle; S4. The directional drill drives the drill rod and the air jet puncher to rotate and gradually withdraw from the borehole. The self-pressurized air jet is ejected from the air jet puncher to destroy the coal body, thereby performing the punching operation; S5. After the punching operation is completed, the air pump is turned off, the steel ball slides out of the drill pipe, and the drill pipe, the air jet puncher and the drill bit are withdrawn. At this time, the slider moves backward under the action of the spring, and the air flow channel 1 and the air flow channel 4 in the outer pipeline are blocked again; S6. Adjust the angle of the directional drill and repeat steps S1-S5 at the new drilling location to perform the punching operation at the new drilling location.

Images