Self-pressurization air jet puncher

Abstract

The utility model belongs to the technical field of coal mine gas control and coal bed gas development, and particularly relates to a self-pressurization air jet puncher which is provided with an inner layer pipeline and an outer layer pipeline, and self-pressurization assemblies are arranged at the upper and lower symmetrical positions in the outer layer pipeline respectively. Each self-pressurization assembly comprises a miniature screw air compressor and an air flow channel, a damping turbofan and a Laval nozzle are arranged in the air flow channel, the damping turbofan is arranged at the tail end of a driving shaft of the miniature screw air compressor, an air inlet of the miniature screw air compressor is connected with the inner-layer pipeline through the air flow channel, and an air outlet of the miniature screw air compressor is connected with the outer-layer pipeline through the air flow channel. An exhaust port of the micro screw air compressor is communicated with the outside through an 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 utility model belongs to coal mine gas control and coal bed gas development technical field, especially relates to a self-pressurized air jet puncher. BACKGROUND

[0002] Air jet punch as a new type of coal bed permeability enhancement and gas extraction technology, can realize coal bed waterless permeability enhancement and pressure relief, air jet builds stable pressure relief space in the drilling hole during punching, avoids the water lock effect, and can effectively improve the punching effect. The ordinary air jet puncher only relies on the external air source to provide pressure, and the energy utilization rate is low. When breaking hard coal seam, the external air source needs to provide high pressure air, and the required cost is high. It is difficult to adapt to different coal seam conditions, which limits its effect and efficiency in practical application.

[0003] To solve the problems of ordinary puncher, the utility model provides a kind of air jet puncher that can realize internal air self-pressurization. The puncher increases air pressure when air provided by external air source reaches the inside of the puncher, thereby significantly increasing the speed and impact force of air jet, enhancing the coal breaking capacity, and adjusting the gas flow and pressurization effect inside the puncher according to different working conditions, enhancing the adaptability to different coal seam conditions, and providing a kind of efficient and reliable technical equipment for air jet punching technology. CONTENT OF THE UTILITY MODEL

[0004] The utility model aims at providing a kind of self-pressurized air jet puncher, the utility model is based on traditional puncher, changes hydraulic punching to air jet punching, and installs air jet puncher between drill rod and drill bit. The device can realize self-pressurization of air in the drill rod based on the built-in micro screw air compressor of air jet puncher, thereby improving the breaking efficiency of air jet to coal body.

[0005] To achieve the above purpose, the utility model adopts the technical scheme that:

[0006] A kind of self-pressurized air jet puncher, the air jet puncher is provided with inner pipeline and outer pipeline, and one self-pressurization assembly is arranged at upper and lower symmetrical positions in the inner pipeline, each self-pressurization assembly includes a micro screw air compressor and a wind flow channel, a damping vortex fan and a lafayette nozzle are arranged in the wind flow channel, the damping vortex fan 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 air outlet of the micro screw air compressor is communicated with the outside through the wind flow channel;Two fixed blocks are arranged on the inner wall of the inner pipeline in a symmetrical manner, one spring is arranged on each fixed block, a sliding block is arranged at the end of the spring, and the sliding block blocks the wind flow channel opening where the damping vortex fan is located and the air inlet of the micro screw air compressor when the spring is in a natural state.

[0007] Further, the air flow channel includes air flow channel one, air flow channel two, air flow channel three and air flow channel four, the air flow channel one is connected with the air inlet of the micro screw air compressor, the damping vortex fan is located in the air flow channel four, the air flow channel one and the air flow channel four are connected with the inner layer pipeline when the spring is in the compressed state, each slider blocks the air flow channel one and the air flow channel four when the spring is in the natural state, the air flow channel three is connected with the air outlet of the micro screw air compressor and is provided with a Laval nozzle at the end and is connected with the outside, the air flow channel two is connected with the air outlet of the damping vortex fan and is connected with the outside at the other end.

[0008] Further, it further includes a steel ball in the inner layer drill rod, 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 with the internal pipeline of the air jet puncher and has the same diameter.

[0009] Further, the slider in the air jet puncher is a hollow cylinder, the outer diameter of the slider matches the inner layer pipeline of the air jet puncher, and a gap is arranged between the two fixed blocks.

[0010] Further, the outer layer pipeline is further provided with an air volume adjusting channel, the air volume adjusting channel is connected with the air flow channel one and is provided with a plugging bolt inside.

[0011] Further, the micro screw air compressor is provided with a sealed shell outside, the sealed shell is provided with a driving screw and a driven screw which are engaged with each other, the driving screw is sleeved on the driving shaft, the driven screw is movably arranged in the sealed shell, and the driving screw and the driven screw are both provided with tooth grooves which are engaged with each other.

[0012] Further, the air jet puncher is provided with an internal thread and an external thread at two ends respectively.

[0013] The self-pressurizable air jet puncher needs to be connected and matched with the existing drilling equipment during use, and specifically includes the following steps:

[0014] S1. Water is added to the water tank, a high-pressure hose is used to connect the high-pressure water pump to the air tail inlet, the air tail is connected with the internal passage of the drill rod, the self-pressurizable air jet puncher is installed between the drill bit and the drill rod, the high-pressure water pump and the directional drilling machine are turned on, the water pressure is set to 0.5 MPa, and the drilling work is performed, the water flow passes through the internal passage of the drill rod and the inner layer pipeline slider passage of the air jet puncher in sequence, and finally the water flow reaches the inside of the drill bit and is sprayed out through the drill bit nozzle for cooling and dust reduction.

[0015] S2. After the drilling is completed, the directional drilling machine and the high-pressure water pump are turned off, the high-pressure water pump and the air tail are disconnected, and the residual water flow in the drill rod and the inner layer pipeline of the self-pressurizable air jet puncher is discharged.

[0016] S3. When there is no water flow out, the steel ball is put into the air tail inlet, the air pressure pump is connected to the air tail inlet by using a high-pressure hose, the air pressure pump is opened, when the gas pressure in the storage tank reaches 5MPa, the valve is opened, the high-pressure air is introduced into the inner drill pipe, and the air release pressure is controlled to be 1MPa by the pressure gauge, the high-pressure gas is communicated with the drill pipe inside from the air tail inlet, the high-pressure gas reaches the inner pipeline of the air jet puncher through the drill pipe inside passage, and the steel ball is taken to the inner pipeline of the air jet puncher, when the steel ball collides with the slider of the inner pipeline, the spring retracts the slider to drive the slider to move forward, after the slider moves, the gas is communicated with wind flow channel one and wind flow channel four in the outer pipeline, part of the gas drives the damping vortex fan to rotate through the wind flow channel four, the damping vortex fan drives the driving shaft to rotate to make the micro screw air compressor work, the gas after the damping vortex fan is discharged to the outside of the air jet puncher through the wind flow channel two and is used for discharging slag; the other part of the gas reaches the micro screw air compressor inlet through the wind 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 to compress the gas in it, the compressed gas is discharged from the micro screw air compressor exhaust port, and finally reaches the Laval nozzle through the wind flow channel three, and is accelerated and sprayed out from the Laval nozzle;

[0017] S4. The directional drilling machine drives the drill pipe and the air jet puncher to rotate, and gradually exits the drill hole, the self-pressurized air jet is sprayed out from the air jet puncher to damage the coal body, so that the punching operation is performed;

[0018] S5. After the punching operation is completed, the air pressure pump is closed, 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 wind flow channel one and wind flow channel four in the outer pipeline are re-blocked;

[0019] S6. The angle of the directional drilling machine is adjusted, steps S1-S5 are repeated at a new drilling site, and the punching operation can be performed at the new drilling site.

[0020] The utility model has the advantages of:

[0021] 1. The utility model can realize self-pressurization of air in the puncher, significantly improve the air jet speed and impact force, enhance the air jet coal breaking capacity, and improve the punching efficiency;

[0022] 2. The utility model can adjust the gas flow and pressurization effect in the puncher according to different working conditions, and enhance the adaptability of the air jet punching technology to different coal seam conditions. DRAWINGS

[0023] Figure 1 The use state of the air jet puncher with self-pressurization is shown in the reference diagram.

[0024] Figure 2The utility model discloses a self-pressurized air jet puncher structure schematic diagram.

[0025] Figure 3 The utility model discloses a self-pressurized air jet puncher internal micro screw rod air compressor structure schematic diagram.

[0026] Figure 4 The utility model discloses a drill rod structure schematic diagram. Specific implementation Embodiment

[0027] As Figures 1-4 The utility model discloses a self-pressurized air jet puncher, the air jet puncher 10 needs to be connected with the existing drilling equipment and be used in use, and the specific existing drilling equipment includes drill bit 11, directional drilling machine 9, drill pipe 8, gas tail 5, air pressure pump 1, high pressure gas storage tank 2, valve 3, pressure gauge 4, water tank 6, high pressure water pump 7. One end of drill pipe 8 has internal thread 29, and the other end has external thread 30, can select multiple connections according to the need in use, and the air jet puncher is installed through thread at the front end of drill pipe 8, and drill bit 11 is installed through thread at the front end of air jet puncher, and the drill bit has internal pipeline and can be watered, and the front end of drill bit is equipped with nozzle and is used to spray water and cool down and reduce dust when drilling.

[0028] The air jet puncher 10 mainly comprises an inner pipe and an outer pipe, the inner pipe is communicated with the inner passage of the drill pipe and has the same diameter, the outer pipe has a miniature screw air compressor 17, a miniature screw air compressor drive shaft 22, a damping vortex fan 23, a Laval nozzle 20, and air volume adjusting channels 12, air flow channels 14, 15, 19 and 21, the air flow channel 14 is communicated with the air inlet 16 of the screw air compressor, before operation, the area of the air flow channel 14 can be adjusted by the way of inserting a pipe according to the working conditions of different operations, so as to adjust the air inlet volume of the screw air compressor, and after adjustment, the air volume adjusting channel is blocked by the blocking bolt 13, the damping vortex fan 23 and the miniature screw air compressor drive shaft 22 are in the air flow channel 21, the damping vortex fan is installed at the end of the miniature screw air compressor drive shaft, when the damping vortex fan rotates, it can drive the miniature screw air compressor drive shaft to rotate, so that the miniature screw air compressor 17 starts to work, the Laval nozzle 20 is connected with the air outlet 18 of the screw air compressor through the air flow channel 19 and communicated with the outside, the outer pipe is solid except the miniature screw air compressor and the channels, the inner wall of the inner pipe is symmetrically provided with two fixed blocks 26, each fixed block is provided with a spring 25, the end of the spring is provided with a sliding block 24, the center passage is between the two sliding blocks, the sliding block is a hollow cylinder, the outer diameter of the sliding block matches the inner pipe of the air jet puncher, the air flow channel 14 and the air flow channel 21 of the outer pipe are outside the two sliding blocks, when the spring is in a natural state, the sliding block can block the air flow channel 14 and the air flow channel 21, when the sliding block moves, the spring deforms, so that the inner pipe is communicated with the air flow channel 14 and the air flow channel 21 outside.

[0029] When drilling operation is performed, the high-pressure water pump 7 is connected through the air tail inlet 5 and the drill pipe 8, the high-pressure water flows through the air jet puncher 10 from the inner passage of the drill pipe, at this time, the water pressure is small and the sliding block 24 does not move, finally reaches the inside of the drill bit 11 through the center passage of the inner pipe of the air jet puncher, and the water flow is sprayed from the nozzle at the front end of the drill bit, which can cool and reduce dust during drilling.

[0030] When the punching operation is performed, the steel ball is put into the air tail inlet 5, the air pressure pump 1 is communicated through the air tail inlet and the drill pipe 8, the high pressure gas carries the steel ball to the inner pipeline of the air jet puncher 10, when the steel ball collides with the sliding block 24 of the inner pipeline, the spring 25 is contracted, the steel ball drives the sliding block to move backward and close to the fixed block 26, after the sliding block moves, the high pressure gas is communicated with the wind flow channel one 14 and the wind flow channel four 21 in the outer pipeline, the gas passes through the wind flow channel four, drives the damping vortex fan 23 to rotate, the damping vortex fan drives the micro screw air compressor drive shaft 22 to rotate, so that the micro screw air compressor 17 works, the gas after the damping vortex fan can be discharged from the wind flow channel two 15 to the outside of the air jet puncher, directly to the inside of the drilling and used for discharging slag; the gas reaches the screw air compressor inlet 16 through the wind flow channel one 14, the screw air compressor inlet is opened, the gas enters the screw air compressor, at this time, the high pressure air in the inner pipeline makes the screw air compressor work, the gas enters the closed space formed between the screw tooth groove and the screw air compressor sealing shell 27, with the rotation of the screw 28, the volume of the closed space formed between the screw tooth groove and the screw air compressor sealing shell gradually decreases, so that the gas in the closed space is compressed, the compressed gas is discharged from the screw air compressor exhaust port 18 and finally reaches the Laval nozzle 20 through the wind flow channel and is accelerated and sprayed out by the Laval nozzle.

[0031] Drill pipe screw air compressor related material balance:

[0032] The flow of the gas entering the drill pipe:

[0033]

[0034] In the formula, Q is the gas flow; r is the internal passage radius of the drill pipe, which is 2cm; v is the gas flow rate, which is 8m / s.

[0035] The gas flow entering the screw air compressor inlet is:

[0036]

[0037] In the formula, Q2 is the gas flow entering one screw air compressor; A1 is the cross-sectional area of the wind flow channel one adjusted through the inner tube; A2 is the cross-sectional area of the wind flow channel four, which is 3.14cm 2 .

[0038] Adjusting the cross-sectional area of the wind flow channel one to 0.0314cm 2 , the Q2 at this time can be calculated as 0.0029 m 3 / min. The normal screw air compressor inlet flow of the size which is about 10 times the size of the micro screw air compressor in the utility model is about 2.5m 3 / min, the volume of which is about 1000 times of the micro screw air compressor, if the volume of the screw air compressor is reduced by 1000 times, the intake flow is 0.0025 m 3 / min, Q2 is 0.0029 m 3 / min, the difference is small, and when the cross-sectional area of the air flow passage is adjusted to reduce Q2, the intake flow of the air flow passage four is increased, the rotating speed of the screw air compressor is increased, the rotating speed is increased, the intake flow that can be borne by the screw air compressor is increased, so Q2 meets the requirement of the screw air compressor for pressure increase. In actual operation, due to the limitation conditions such as leakage, suction resistance and rotating speed, when the volume of the screw air compressor is increased, the intake flow cannot be increased in proportion, so the intake flow that can be borne by the micro screw air compressor in the utility model is much larger than 0.0025 m 3 / min, so the intake flow of the screw air compressor can be adjusted flexibly according to different working conditions by adjusting the area of the air flow passage.

[0039] The compression process in the screw air compressor is very fast, and the compression process is close to an adiabatic compression process, so the gas pressure at the exhaust port of the screw air compressor can be calculated according to the following formula:

[0040]

[0041] In the formula, P1 is the gas pressure at the intake port of the screw air compressor, P2 is the gas pressure at the exhaust port of the screw air compressor, V1 is the intake volume of the screw air compressor, V2 is the exhaust volume of the screw air compressor, k is the adiabatic index of air, and k is 1.4.

[0042] The compression ratio of the screw air compressor has no direct relationship with the size of the screw air compressor, and mainly depends on the pitch and tooth shape design of the screw, so that V1 / V2 is 3:1, and P1 is 1 MPa. P2 can be calculated as 4.66 MPa.

[0043] The gas velocity calculation formula of the Laval nozzle after acceleration is as follows:

[0044]

[0045] In the formula, P e is the gas pressure at the outlet of the Laval nozzle, P0 is the gas pressure at the inlet of the Laval nozzle, P0=P2, and Ma is the Mach number at the outlet of the Laval nozzle.

[0046] P0 is 4.66 MPa, when the expansion ratio of the Laval nozzle is constant, the gas pressure at the outlet is also constant, and when the expansion ratio of the Laval nozzle is 1.12, P eMa is 2.24. The device and method of the utility model can accelerate the air to the super-high-speed air jet above 2 Mach, can effectively destroy the coal body, and thus can perform the air jet punching operation.

[0047] The related calculation of the inner layer pipeline sliding block of the air jet puncher is as follows:

[0048] Neglecting the factors of the along-the-way loss and the friction force, the gas pressure when punching is calculated:

[0049]

[0050] In the formula, P3 is the gas pressure when the sliding block can be moved; r2 is the radius of the steel ball, which is 2 cm; m1 is the mass of the steel ball, which is 270 g; m2 is the mass of the sliding block, which is 200 g; k2 is the spring stiffness coefficient, which is 12500 N / m; and x is the spring contraction distance.

[0051] When the spring is contracted by 4.5 cm, the inner layer pipeline gas can completely enter the wind flow channel one and the wind flow channel four, and when x is 4.5 cm, P3 can be calculated as 0.9 MPa, that is, when the gas pressure is greater than 0.9 MPa when punching, the inner layer pipeline gas can completely enter the wind flow channel one and the wind flow channel four.

[0052] The water pressure when drilling is calculated:

[0053]

[0054] In the formula, P4 is the water pressure when drilling; A3 is the side area of the side of the water flow impacting the sliding block, which is 3.14 cm 2 .

[0055] When the spring is contracted by 1.4 cm or less, the wind flow channel four is still blocked by the sliding block, and when x is 1.4 cm, P4 can be calculated as 0.56 MPa, that is, when the water pressure is less than 0.56 MPa when drilling, the wind flow channel one and the wind flow channel four are still blocked by the sliding block, and the inner layer pipeline water flow cannot enter.

Claims

1. A self-pressurizable air jet piercer characterized by: The air jet puncher is provided with an inner pipeline and an outer pipeline, and a self-pressurizing assembly is arranged at a symmetrical position of the outer pipeline, each self-pressurizing assembly comprising a micro screw air compressor and an air flow channel, the air flow channel being provided with a damping vortex fan and a Laval nozzle, the damping vortex fan being arranged at the end of the driving shaft of the micro screw air compressor, the air inlet of the micro screw air compressor being connected with the inner pipeline through the air flow channel, and the air outlet of the micro screw air compressor being communicated with the outside through the air flow channel; two fixed blocks are arranged at the inner wall of the inner pipeline in a symmetrical manner, a spring is arranged on each fixed block, and a sliding block is arranged at the end of the spring, the sliding block blocking the air flow channel and the air inlet of the micro screw air compressor when the spring is in a natural state.

2. The self-pressurizable air jet punch of claim 1, wherein: The air flow channel comprises an air flow channel one, an air flow channel two, an air flow channel three and an air flow channel four, the air flow channel one being connected with the air inlet of the micro screw air compressor, the damping vortex fan being arranged in the air flow channel four, the air flow channel one and the air flow channel four being communicated with the inner pipeline when the spring is in a compressed state, each sliding block blocking the air flow channel one and the air flow channel four when the spring is in a natural state, the air flow channel three being connected with the air outlet of the micro screw air compressor and provided with a Laval nozzle at the end and communicated with the outside, and the air flow channel two being communicated with the air outlet of the damping vortex fan and communicated with the outside at the other end.

3. The self-pressurizable air jet punch of claim 1, wherein: The steel ball is matched with the inner diameter of the drill pipe, and the inner diameter of the drill pipe is communicated with the inner pipeline of the air jet puncher and has the same diameter.

4. The self-pressurizable air jet punch of claim 1, wherein: The sliding block in the air jet puncher is a hollow cylinder, the outer diameter of which is matched with the inner pipeline of the air jet puncher, and a gap is arranged between the two fixed blocks.

5. The self-pressurizable air jet punch of claim 1, wherein: The outer pipeline is further provided with a gas adjustment channel, the gas adjustment channel being communicated with the air flow channel one and provided with a blocking bolt inside.

6. The self-pressurizable air jet punch of claim 1, wherein: The micro screw air compressor is provided with a sealing shell, the sealing shell being provided with a driving screw and a driven screw which are meshed with each other, the driving screw being sleeved on the driving shaft, the driven screw being movably arranged in the sealing shell, and the driving screw and the driven screw being provided with tooth grooves which are meshed with each other.

7. The self-pressurizable air jet punch of claim 1, wherein: The air jet puncher is provided with an inner thread and an outer thread at two ends.

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