Blowout prevention device for drilling hole construction in bottom extraction tunnel of coal mine

Abstract

A blowout prevention device for bottom extraction tunnel drilling construction in a coal mine includes a drilling expansion section sealing device, a wing-shaped water-slag gas diversion device, a drill rod sealing guide device, a control system, a negative pressure accumulator and a water-slag collector; the upper port of the wing-shaped water-slag gas diversion device is connected to the middle port of the drilling expansion section sealing device through a flange, the lower part of the wing-shaped water-slag gas diversion device is connected to the top of the water-slag collector through a lower connecting pipe, the upper part of the wing-shaped water-slag gas diversion device is connected to the negative pressure accumulator through an upper connecting pipe, the drill rod sealing guide device is arranged at the lower port of the wing-shaped water-slag gas diversion device, and the upper part of the water-slag collector is connected to the upper part of the negative pressure accumulator through a negative pressure extraction pipe. The present invention has a scientific principle, a reasonable design, and a high degree of automation. It can facilitate the separation of gas, water, and coal slag during the through-layer drilling construction process, and prevent gas from pouring into the tunnel when a blowout occurs during the bottom extraction tunnel drilling construction process, causing a gas over-limit accident.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mine gas extraction, and in particular relates to a blowout prevention hole device for drilling hole construction of a coal mine bottom gas extraction lane. Background Art

[0002] Bottom extraction tunnel, also known as floor tunnel, is located in the rock layer below the coal seam, and refers to the tunnel arranged on the bottom of the coal seam. Drilling through the coal seam from the coal seam floor tunnel to the coal seam for gas extraction has become a necessary means for regional and local elimination of gas outbursts in high-gas mines and coal and gas outburst mines. In the process of through-layer drilling construction, hydraulic slag removal and hydraulic coal cutting are generally used. After the drill rod enters the coal seam, a large amount of gas, accompanied by coal slag and water, rushes out of the borehole instantly, which can easily cause blowouts, causing gas over-limit alarms in the floor tunnel, causing gas accidents, which can affect production in minor cases and cause casualties in serious cases. Summary of the invention

[0003] In order to solve the deficiencies in the prior art, the present invention provides a blowout prevention device for coal mine bottom extraction tunnel drilling construction, which is intended to prevent gas over-limit accidents in the blowout holes during the bottom plate tunnel drilling construction process; the ejected gas, coal slag and water are orderly guided, separated and stored, so that drilling can proceed steadily.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions: a blowout prevention device for bottom extraction tunnel drilling construction in a coal mine, comprising a hole sealing device for a drilling and expansion section, a wing-shaped water-slag gas diversion device, a drill rod sealing guide device, a control system, a negative pressure accumulator and a water-slag collector;

[0005] The upper port of the wing-shaped water-slag gas diversion device is connected to the middle port of the drilling expansion section sealing device through a flange, the lower part of the wing-shaped water-slag gas diversion device is connected to the top of the water-slag collector through a lower connecting pipe, the upper part of the wing-shaped water-slag gas diversion device is connected to the negative pressure energy accumulator through an upper connecting pipe, the drill rod sealing guide device is arranged at the lower port of the wing-shaped water-slag gas diversion device, the upper part of the water-slag collector is connected to the upper part of the negative pressure energy accumulator through a negative pressure extraction pipe, the exhaust port of the negative pressure energy accumulator is connected to the gas extraction pipeline in the tunnel through a gas discharge pipe, and the control system is respectively connected to the wing-shaped water-slag gas diversion device, the water-slag collector and the negative pressure energy accumulator through control cables.

[0006] The sealing device for the drilling and expanding section includes a sealing pipe, a first flange and a second flange. The first flange is coaxially arranged on the outer circle of the sealing pipe, the second flange is coaxially arranged on the lower end of the sealing pipe, the first flange is located above the second flange, and the distance from the first flange to the second flange is smaller than the distance from the first flange to the upper end of the sealing pipe.

[0007] The wing-shaped water-slag-gas diversion device comprises a central tube, an upper wing tube, a lower wing tube, a third flange and a fourth flange. The third flange is coaxially arranged at the upper port of the central tube, the fourth flange is coaxially arranged at the lower port of the central tube, the upper ports of the upper wing tube and the lower wing tube are respectively connected to the upper part and the lower part of the central tube, the upper wing tube and the lower wing tube are symmetrically arranged about the center of the central tube, the lower port of the upper wing tube is connected to the upper port of the upper connecting tube through a first pipe joint, and the lower port of the lower wing tube is connected to the upper port of the lower connecting tube through a second pipe joint.

[0008] The drill pipe sealing guide device comprises a fifth flange, a sixth flange, a positioning sleeve, an inner sleeve and a plurality of rollers. The outer circumference of the fifth flange is provided with a circle of external connection holes corresponding to the fourth flange one by one. The fifth flange and the fourth flange are connected correspondingly by bolt assemblies passing through the external connection holes. The lower surface of the fifth flange is provided with a circle of internal threaded blind holes on the inner side of the external connection holes. The outer circumference of the sixth flange is provided with a circle of internal connection holes corresponding to the internal threaded blind holes one by one. Bolts are inserted into the internal connection holes from bottom to top. The upper part of the bolts is inserted into and threaded into the internal threaded blind holes. The upper end face of the positioning sleeve is coaxially fixedly connected with the lower end face of the sixth flange. The inner diameter of the sixth flange is larger than the inner diameter of the positioning sleeve. The inner sleeve is coaxially arranged inside the sixth flange. A plurality of rollers are rollingly arranged in an annular gap between the outer circle of the inner sleeve and the inner circle of the sixth flange. The center hole of the inner sleeve is circular or triangular matching the cross-sectional shape of the drill pipe. When the center hole of the inner sleeve is circular, the inner circle of the inner sleeve is provided with a guide key along the axial direction, and the outer circle of the drill pipe is provided with a guide groove matching the guide key along the axial direction.

[0009] The water slag collector includes a collection box in the shape of a rectangular parallelepiped, with a balanced air inlet and a slag inlet pipe joint provided on the top of the collection box, an upper portion of one side surface of the collection box being connected to the inlet of the negative pressure extraction pipe, the slag inlet pipe joint being connected to the outlet of the lower connecting pipe, and a sewage pipe being provided at the lower portion of one side surface of the collection box.

[0010] The balanced air inlet is arranged at a left rear corner of the top of the collecting box, and the drain pipe is arranged at a right front corner of the bottom of the collecting box. A balanced air inlet pipe is fixedly arranged in the balanced air inlet, and a quick-plug connector is provided at the upper end of the balanced air inlet pipe. A row of at least three injection branch pipes arranged at intervals from the left rear side to the right front side is laid on the lower surface of the top of the collecting box. Both ends of the injection branch pipes are blocked, and the lower end of the balanced air inlet pipe is connected to all the injection branch pipes through an injection main pipe. The lower part of each injection branch pipe is provided with an injection hole that sprays toward the right front and lower side.

[0011] A material guiding bottom plate which is high from the left rear side to the right front side is laid at the bottom of the collecting box, and the lowest point of the right front side of the material guiding bottom plate is flush with the lower edge of the inner hole of the sewage pipe.

[0012] The negative pressure energy accumulator includes a bracket, on which a negative pressure box is arranged, the upper part of the negative pressure box is a quadrangular prism-shaped structure, the lower part of the negative pressure box is a quadrangular pyramid-shaped structure which is larger at the top and smaller at the bottom, the top of the negative pressure box is connected to the upper wing pipe by a drainage pipe, the top of the negative pressure box is provided with a gas inlet pipe joint, a large-diameter inlet pipe joint and a large-diameter outlet pipe joint, the gas inlet pipe joint is connected to the outlet of the negative pressure extraction pipe, the large-diameter inlet pipe joint is connected to the lower port of the upper connecting pipe, the large-diameter outlet pipe joint is connected to the inlet of the gas discharge pipe, and a water slag discharge pipe is provided at the lower end of the quadrangular pyramid structure of the negative pressure box.

[0013] An inner sleeve is connected to the internal thread of the large-caliber air outlet pipe joint, a filter is fixedly arranged at the lower end of the inner sleeve, and the central hole of the inner sleeve is a hexagonal column structure.

[0014] The control system includes a PLC controller, a pressure sensor, a gas sensor, a first sewage discharge solenoid valve, a second sewage discharge solenoid valve, a first ultrasonic sensor, a second ultrasonic sensor, a blowout prevention normally closed solenoid valve, an exhaust solenoid valve, and a balancing solenoid valve; the pressure sensor and the gas sensor are both arranged on the upper wing pipe, the first sewage discharge solenoid valve is arranged on the sewage discharge pipe, the second sewage discharge solenoid valve is arranged on the water slag discharge pipe, the second sewage discharge solenoid valve is arranged on the water slag discharge pipe, the first ultrasonic sensor is arranged on the top of the collecting box to monitor the water slag height in the collecting box, the second ultrasonic sensor is arranged on the top of the negative pressure box to monitor the water slag height in the negative pressure box, the blowout prevention normally closed solenoid valve is installed on the large-diameter air inlet pipe joint, the exhaust solenoid valve is installed on the large-diameter air outlet pipe joint, and the balancing solenoid valve is installed on the top of the negative pressure box.

[0015] With the above technical solution, during the drilling construction, a larger drill bit is first used to construct the expansion section of the outer port of the borehole, and the length of the expansion section is greater than or equal to the distance from the first flange to the upper port of the sealing pipe. After the expansion section is completed, a sealant is applied to the outer wall of the sealing pipe from the first flange to the upper port of the sealing pipe, and then the sealing pipe is quickly inserted into the expansion section, and a hole is drilled into the rock at the bottom of the bottom extraction tunnel through the mounting hole on the first flange, and then the expansion screw is passed through the mounting hole to fix the drilling expansion section sealing device on the rock.

[0016] When installing, the upper end of the wing-shaped water-slag-gas diversion device is connected to the second flange through the third flange, the sealing ring, screws and nuts, and the lower end is connected to the drill pipe sealing guide device through the fourth flange. The wing-shaped water-slag-gas diversion device is a device for diverting rock cuttings, coal seam cuttings, and gas generated during the drilling process. The angle formed by the upper wing pipe, the lower wing pipe and the sealing pipe forms a curved surface transition, which is convenient for separating coal slag, water, and gas generated during drilling. Since the through-layer drilling construction has a certain inclination angle, the lower wing pipe used for diverting water and slag is placed downward (located at the lower side of the borehole). During operation, water and slag flow into the water-slag collector through the lower wing pipe and the lower connecting pipe due to gravity. The upper wing pipe is arranged on the upper side (located at the lower side of the borehole), and a drainage pipe is connected between the upper wing pipe and the negative pressure accumulator. The gas gushing out during small-scale drilling operations is discharged into the negative pressure accumulator through the drainage pipe under the action of negative pressure. In addition, since the density of gas is greater than that of air, the position of the negative pressure accumulator is lower than the upper wing pipe, and the gas can also easily flow from the drainage pipe into the negative pressure accumulator.

[0017] The drill pipe sealing guide device is used to seal the gap between the drill pipe and the central tube of the wing-shaped water-gas-slag diversion device, and prevent the slag and airflow in the wing-shaped water-gas-slag diversion device from rushing out of the tunnel and causing gas to exceed the limit. The inner sleeve is an annular sleeve that is in close contact with the drill pipe. A suitable inner sleeve can be selected according to drill pipes of different diameters and shapes. The inner diameter of the inner sleeve is roughly equal to the outer diameter of the drill pipe. The fifth flange is connected to the fourth flange, and the inner sleeve is connected inside the sixth flange and connected by roller rotation and lubricated with lubricating oil. In this way, when the drill pipe passes through the positioning sleeve, the inner sleeve and extends into the central tube, the inner sleeve rotates together with the drill pipe inside the sixth flange, and under the limit of the fourth flange and the positioning sleeve, it will not move axially along the direction of the drill pipe, ensuring that gas will not flow into the tunnel through the drill pipe sealing guide device during drilling and even during drilling and spraying, thereby ensuring the safety of drilling.

[0018] The structure of the negative pressure box of the negative pressure accumulator is a rigid sealed hollow negative pressure box made of steel plate. Its volume is determined by the amount of coal powder and gas gushing out of the spray hole. There is a certain amount of water at the bottom of the negative pressure box. The gas containing coal powder discharged into the negative pressure box has a certain dust removal effect after entering the negative pressure box.

[0019] The structure of the water-slag collector is also a rigid sealed hollow collection box made of steel plate, and its volume is determined according to the amount of water and slag discharged from a borehole. During drilling operations, the balanced air intake pipe is connected to the air in the tunnel, and is connected to the inside of the collection box through the injection hole on the injection branch pipe, thereby ensuring the pressure balance inside and outside the collection box and the reliability of negative pressure gas extraction. During drilling, water and slag flow into the bottom of the collection box through the lower wing pipe and the lower connecting pipe to deposit. When the first ultrasonic sensor detects that the water slag has deposited to a certain height, the PLC controller sends an open signal to the first sewage discharge solenoid valve, and the water-slag mixture is discharged from the sewage discharge pipe. When the present invention is not in use, the water slag deposited inside the collection box is completely cleaned up, and the high-pressure water pipe can be connected to the quick-plug connector. After the high-pressure water passes through the balanced air intake pipe, the injection main pipe and several injection branches, it is finally sprayed out through the injection hole on the injection branch pipe, and the surface of the guide bottom plate laid at the bottom of the collection box is thoroughly cleaned up, and the water-slag mixture is discharged through the sewage discharge pipe. The material guide bottom plate is tilted from the high left rear side to the low right front side, which avoids the formation of dead corners for water slag deposition and helps the water slag to be discharged smoothly from the collection box.

[0020] The control system mainly uses a PLC controller, and is composed of a human-computer interaction display interface, relays, digital-to-analog conversion modules, explosion-proof housings, normally open solenoid valves, normally closed solenoid valves, pressure sensors, gas concentration sensors, ultrasonic sensors, sound and light prompt devices, connecting wires, etc. The PLC controller collects and processes information such as pressure, gas concentration, and deposition depth, and controls several solenoid valves to open or close, playing a role in key actions such as slag removal and gas collection. The sound and light prompt device can provide some voice prompts based on the construction situation and the working status of the device. Key information can be displayed on the screen through the human-computer interaction interface, making it easy to grasp the data in the drilling construction at any time. The PLC controller can realize automatic control during the spraying, and can also be manually controlled by technicians through the touch screen.

[0021] According to the drilling construction position, drilling rig position, and slag sedimentation storage position, the water slag collector and negative pressure accumulator should be placed reasonably so as not to affect the drilling rig construction. Fix the controller in a convenient position for operation, connect the solenoid valves and sensors on the negative pressure accumulator and water slag collector to the interface position of the controller correctly through wires and convenient plugs according to the instructions, power on self-test, set warning and action parameters, such as the warning readings of the gas sensor and pressure sensor, and the detection readings of the ultrasonic sensor. Select the control type (manual control or automatic control) for use.

[0022] The construction process of the present invention is as follows: after the drill rod is inserted into the positioning sleeve and passes through the inner sleeve, the center tube and the sealing tube, the outer circle of the drill rod and the inner wall clearance of the inner sleeve are matched, the drilling rig is started to start drilling, and at the same time, the exhaust solenoid valve is opened and the blowout prevention normally closed solenoid valve is closed.

[0023] During the drilling process of rock strata or coal seams with no signs of blowholes, water and slag enter the central tube and enter the collection box through the lower connecting pipe due to the effect of gravity. The gas generated during the drilling process is lighter than air in density and will enter the negative pressure box along the drainage pipe under the action of negative pressure in the negative pressure accumulator. Due to the presence of coal slag, a small amount of gas generated in the water-slag collector will enter the negative pressure box through the negative pressure extraction pipe on its upper part. The gas in the negative pressure box finally enters the gas extraction pipeline in the tunnel through the gas discharge pipe.

[0024] When the drill rod is drilling upward, there is a small gap between the drill rod and the inner sleeve. The guide groove on the outer circle of the drill rod cooperates with the guide key on the inner wall of the inner sleeve. When the drill rod rotates at high speed, it drives the inner sleeve inside the sixth flange and rotates through the roller. The drill rod moves forward along the guide key. Due to the negative pressure in the center tube of the inner sleeve, gas and dust will not overflow through the gap. When drilling into the coal seam, a large amount of gas generated by gas pressure or hydraulic coal cutting will suddenly spray out along the borehole, which will produce a spray hole. Due to the outflow of a large amount of gas during the spray hole, the monitoring signals of the gas sensor and the pressure sensor will be affected in a short time. The value of the signal rises rapidly and reaches the preset threshold. The controller will judge according to the signal, issue an audible and visual warning, and voice prompt to stop drilling. At the same time, it will send a signal to open the normally closed solenoid valve for preventing blowout. A large amount of coal powder, water and a small amount of gas will enter the collection box through the lower wing pipe, and then the gas in the collection box will enter the negative pressure box through the negative pressure extraction pipe and flow into the gas extraction pipeline in the tunnel. At the same time, a large amount of gas and part of coal powder will directly enter the negative pressure accumulator through the upper wing pipe. The gas will finally flow into the gas extraction pipeline in the tunnel, and the coal powder will be deposited in the water at the bottom of the negative pressure box due to gravity. The coal powder is removed and deposited at the bottom of the negative pressure box. Until the value of the gas sensor and the value of the pressure sensor are lower than the set value, the controller will continue to send a signal delay for a certain period of time to continue to control the normally closed solenoid valve for preventing blowout to open and maintain gas emission. Until the voice prompt of the PLC controller starts normal drilling. This process can also be controlled manually.

[0025] During the drilling process, the depth of accumulated water and slag in the negative pressure box and the collection box will be detected by the ultrasonic sensor and displayed on the screen of the PLC controller. Once the depth of accumulated water and slag in a container reaches the preset value, the PLC controller will issue an audible and visual warning and voice prompt: stop drilling, discharge the water slag in the negative pressure accumulator, or prompt: stop drilling, discharge the water slag in the water slag collector. Once the drilling stops, the PLC controller will send a signal to the solenoid valve at the slag discharge port of the water slag collector and the negative pressure accumulator where the water and slag accumulation height is limited. The first sewage discharge solenoid valve and the second sewage discharge solenoid valve are opened, and the water slag is discharged from the container. After reaching the predetermined discharge height, the PLC controller sends a signal, the first sewage discharge solenoid valve and the second sewage discharge solenoid valve are closed, and the voice prompt: the slag discharge is completed and drilling can continue. This process can also be manually operated on the control system. When discharging the water slag deposited in the negative pressure box, the PLC controller opens the balance solenoid valve, the pressure inside and outside the negative pressure box is equal, and the water slag in the negative pressure box can be automatically discharged from the negative pressure box under the action of its own gravity.

[0026] In summary, the present invention has a scientific principle, a reasonable design and a high degree of automation. It can facilitate the separation of gas, water and coal slag during the through-layer drilling construction process, and prevent gas from flowing into the tunnel when a blowout hole occurs during the bottom extraction tunnel drilling construction process, causing a gas over-limit accident. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0028] Figure 2 yes Figure 1 Planar layout of the injection main pipe and injection branch pipe on the lower surface of the top of the collecting box of the medium-water slag collector;

[0029] Figure 3 It is a schematic diagram of the assembly of the large-caliber outlet pipe joint, the inner sleeve and the filter;

[0030] Figure 4 It is a disassembled schematic diagram of the drill pipe sealing device;

[0031] Figure 5 yes Figure 3 A schematic diagram of a second embodiment of the inner sleeve;

[0032] Figure 6 yes Figure 3 Schematic diagram of a third embodiment of the inner sleeve. DETAILED DESCRIPTION

[0033] like Figure 1-Figure 4 As shown, the blowout prevention device for bottom extraction tunnel drilling construction in a coal mine of the present invention comprises a hole sealing device for the drilling and expansion section, a wing-shaped water-slag gas diversion device, a drill rod sealing guide device 1, a control system, a negative pressure accumulator and a water-slag collector;

[0034] The upper port of the wing-shaped water-slag gas diversion device is connected to the middle port of the drilling expansion section sealing device through a flange, the lower part of the wing-shaped water-slag gas diversion device is connected to the top of the water-slag collector through a lower connecting pipe 2, the upper part of the wing-shaped water-slag gas diversion device is connected to the negative pressure energy accumulator through an upper connecting pipe 7, and the drill rod sealing guide device 1 is arranged at the lower port of the wing-shaped water-slag gas diversion device. The upper part of the water-slag collector is connected to the upper part of the negative pressure energy accumulator through a negative pressure extraction pipe 8, and the exhaust port of the negative pressure energy accumulator is connected to the gas extraction pipeline 10 in the tunnel through a gas discharge pipe 9. The control system is respectively connected to the wing-shaped water-slag gas diversion device, the water-slag collector and the negative pressure energy accumulator through a control cable 11.

[0035] The sealing device for the drilling and expanding section includes a sealing tube 12, a first flange 13 and a second flange 14. The first flange 13 is coaxially arranged on the outer circle of the sealing tube 12, and the second flange 14 is coaxially arranged on the lower end of the sealing tube 12. The first flange 13 is located above the second flange 14, and the distance from the first flange 13 to the second flange 14 is smaller than the distance from the first flange 13 to the upper end of the sealing tube 12.

[0036] The wing-shaped water-slag-gas diversion device includes a central tube 15, an upper wing tube 16, a lower wing tube 17, a third flange 18 and a fourth flange 19. The third flange 18 is coaxially arranged at the upper end of the central tube 15, and the fourth flange 19 is coaxially arranged at the lower end of the central tube 15. The upper ends of the upper wing tube 16 and the lower wing tube 17 are respectively connected to the upper and lower parts of the central tube 15. The upper wing tube 16 and the lower wing tube 17 are symmetrically arranged about the center of the central tube 15. The lower end of the upper wing tube 16 is connected to the upper end of the upper connecting tube 7 through a first pipe joint 20, and the lower end of the lower wing tube 17 is connected to the upper end of the lower connecting tube 2 through a second pipe joint 21.

[0037] The drill pipe sealing guide device 1 includes a fifth flange 22, a sixth flange 23, a positioning sleeve 24, an inner sleeve 25 and a plurality of rollers 26. The outer circumference of the fifth flange 22 is provided with a circle of outer connection holes 27 corresponding to the fourth flange 19. The fifth flange 22 and the fourth flange 19 are connected correspondingly by bolt assemblies passing through the outer connection holes 27. The lower surface of the fifth flange 22 is provided with a circle of internal threaded blind holes (not shown in the figure) on the inner side of the outer connection holes 27. The outer circumference of the sixth flange 23 is provided with a circle of internal connection holes 28 corresponding to the internal threaded blind holes. The inner connection holes 28 are penetrated from bottom to top. Bolts, the upper part of the bolts extends into and is threaded into the internal threaded blind hole, the upper end face of the positioning sleeve 24 is coaxially fixedly connected with the lower end face of the sixth flange 23, the inner diameter of the sixth flange 23 is larger than the inner diameter of the positioning sleeve 24, the inner sleeve 25 is coaxially arranged inside the sixth flange 23, a plurality of rollers 26 are rollingly arranged in the annular gap between the outer circle of the inner sleeve 25 and the inner circle of the sixth flange 23, the center hole of the inner sleeve 25 is a circle matching the cross-sectional shape of the drill pipe; the inner circle of the inner sleeve 25 is provided with a guide key 3 along the axial direction, and the outer circle of the drill pipe is provided with a guide groove matching the guide key 3 along the axial direction.

[0038] The water-slag collector includes a collecting box 29 in the shape of a rectangular parallelepiped, and a balanced air inlet and a slag inlet pipe joint 30 are provided on the top of the collecting box 29. The upper part of one side surface of the collecting box 29 is connected to the inlet of the negative pressure extraction pipe 8, and the slag inlet pipe joint 30 is connected to the outlet of the lower connecting pipe 2. A sewage pipe 31 is provided at the lower part of one side surface of the collecting box 29.

[0039] A balanced air inlet is arranged at a left rear corner of the top of the collecting box 29, a drain pipe 31 is arranged at a right front corner of the bottom of the collecting box 29, a balanced air inlet pipe 32 is fixedly arranged in the balanced air inlet, a quick-connect connector is provided at the upper end of the balanced air inlet pipe 32, a row of at least three injection branch pipes 33 arranged at intervals from the left rear side to the right front side are laid on the lower surface of the top of the collecting box 29, both ends of the injection branch pipe 33 are blocked, and the lower end of the balanced air inlet pipe 32 is connected to all the injection branch pipes 33 through an injection main pipe 34, and the lower part of each injection branch pipe 33 is provided with an injection hole 4 that sprays toward the right front and lower side.

[0040] A material guiding bottom plate 35 which is high on the left rear side and low on the right front side is laid on the bottom of the collecting box 29 , and the lowest point on the right front side of the material guiding bottom plate 35 is flush with the lower edge of the inner hole of the sewage pipe 31 .

[0041] The negative pressure accumulator includes a bracket 36, on which a negative pressure box 37 is provided. The upper part of the negative pressure box 37 is a quadrangular prism-shaped structure, and the lower part of the negative pressure box is a quadrangular pyramid-shaped structure with a larger upper part and a smaller lower part. The top of the negative pressure box 37 is connected to the upper wing tube 16 via a drainage tube 38. A gas inlet pipe joint 39, a large-diameter inlet pipe joint 40 and a large-diameter outlet pipe joint 41 are provided on the top of the negative pressure box 37. The gas inlet pipe joint 39 is connected to the outlet of the negative pressure extraction pipe 8, the large-diameter inlet pipe joint 40 is connected to the lower port of the upper connecting pipe 7, the large-diameter outlet pipe joint 41 is connected to the inlet of the gas discharge pipe 9, and a water slag discharge pipe 42 is provided at the lower end of the quadrangular pyramid structure of the negative pressure box 37.

[0042] The inner sleeve 43 is connected to the large-caliber outlet pipe joint 41 by internal threads, and a filter screen 44 is fixedly provided at the lower end of the inner sleeve 43, and the central hole of the inner sleeve 43 is a hexagonal column structure. The arrangement of the inner sleeve 43 and the filter screen 44 can prevent dust from entering the gas extraction pipeline 10 in the tunnel. When the filter screen 44 is blocked, the outer hexagonal column wrench can be inserted into the inner sleeve 43, and the outer hexagonal column wrench can be turned to screw the inner sleeve 43 upward to replace the filter screen 44. The filter screen 44 can be fixedly connected to the lower end of the inner sleeve 43 by a number of screws 5 evenly arranged along the circumferential direction of the inner sleeve 43. This makes it easy to disassemble and assemble the filter screen 44.

[0043] The control system includes a PLC controller 45, a pressure sensor 46, a gas sensor 47, a first sewage discharge solenoid valve 48, a second sewage discharge solenoid valve 49, a first ultrasonic sensor 50, a second ultrasonic sensor 51, a blowout prevention normally closed solenoid valve 52, an exhaust solenoid valve 53, and a balancing solenoid valve 54; the pressure sensor 46 and the gas sensor 47 are both arranged on the upper wing tube 16, the first sewage discharge solenoid valve 48 is arranged on the sewage discharge pipe 31, the second sewage discharge solenoid valve 49 is arranged on the water slag discharge pipe 42, the second sewage discharge solenoid valve 49 is arranged on the water slag discharge pipe 42, the first ultrasonic sensor 50 is arranged on the top of the collection box 29 to monitor the water slag height in the collection box 29, the second ultrasonic sensor 51 is arranged on the top of the negative pressure box 37 to monitor the water slag height in the negative pressure box 37, the blowout prevention normally closed solenoid valve 52 is installed on the large-diameter air inlet pipe joint 40, the exhaust solenoid valve 53 is installed on the large-diameter air outlet pipe joint 41, and the balancing solenoid valve 54 is installed on the top of the negative pressure box 37.

[0044] During the drilling construction, a larger drill bit is first used to construct the expansion section of the outer end of the borehole, and the length of the expansion section is greater than or equal to the distance from the first flange 13 to the upper end of the sealing tube 12. After the expansion section is completed, a sealant is applied to the outer wall of the sealing tube 12 from the first flange 13 to the upper end of the sealing tube 12, and then the sealing tube 12 is quickly inserted into the expansion section, and a hole is drilled into the rock at the bottom of the bottom extraction tunnel through the mounting hole on the first flange 13, and then the expansion screw is passed through the mounting hole to fix the drilling expansion section sealing device on the rock.

[0045] When installed, the upper end of the wing-shaped water-slag-gas diverter is connected to the second flange 14 through the third flange 18 and the sealing ring with screws and nuts, and the lower end is connected to the drill pipe sealing guide device 1 through the fourth flange 19. The wing-shaped water-slag-gas diverter is a device for diverting rock cuttings, coal seam cuttings, and gas generated during the drilling construction process. The angle formed by the upper wing pipe 16, the lower wing pipe 17 and the sealing pipe 12 forms a curved surface transition, which is convenient for separating coal slag, water, and gas generated during the drilling construction. Since the through-layer drilling construction has a certain inclination angle, the lower wing pipe 17 used for diverting water and slag is placed downward (located on the lower side of the borehole). During operation, water and slag flow into the water-slag collector through the lower wing pipe 17 and the lower connecting pipe 2 due to gravity. The upper wing pipe 16 is arranged on the upper side (located at the lower side of the borehole), and a drainage pipe 38 is connected between the upper wing pipe 16 and the negative pressure accumulator. The gas gushing out during small-scale drilling operations is discharged into the negative pressure accumulator under the action of negative pressure through the drainage pipe 38. In addition, since the density of gas is greater than that of air, the position of the negative pressure accumulator is lower than the upper wing pipe 16, and the gas can also flow into the negative pressure accumulator from the drainage pipe 38.

[0046] The drill pipe sealing guide device 1 is used to seal the gap between the drill pipe and the central tube 15 of the wing-shaped water-gas-slag diversion device to prevent the slag and airflow in the wing-shaped water-gas-slag diversion device from rushing out of the tunnel and causing gas to exceed the limit. The inner sleeve 25 is an annular sleeve that is in close contact with the drill pipe. A suitable inner sleeve 25 can be selected according to drill pipes of different diameters and shapes. The inner diameter of the inner sleeve 25 is roughly equal to the outer diameter of the drill pipe. The fifth flange 22 is connected to the fourth flange 19, and the inner sleeve 25 is connected and lubricated by rollers 26 in the sixth flange 23. In this way, the drill pipe passes through the positioning sleeve 24 and the inner sleeve 25 and extends into the central tube 15. When drilling, the inner sleeve 25 rotates inside the sixth flange 23 together with the drill pipe, and under the limit of the fourth flange 19 and the positioning sleeve 24, it will not move axially along the direction of the drill pipe, ensuring that gas will not flow into the tunnel through the drill pipe sealing guide device 1 during drilling and even during drilling and spraying, thereby ensuring the safety of drilling.

[0047] The structure of the negative pressure box 37 of the negative pressure accumulator is a rigid sealed hollow negative pressure box 37 made of steel plate. Its volume is determined according to the amount of coal powder and gas gushing out when the spray hole is opened. There is a certain amount of water at the bottom of the negative pressure box 37. The gas containing coal powder discharged into the negative pressure box 37 has a certain dust removal effect after entering it.

[0048] The structure of the water-slag collector is also a rigid sealed hollow collection box 29 made of steel plate, and its size is determined according to the amount of water and slag discharged from a borehole. During drilling operations, the balanced air intake pipe 32 is connected to the air in the tunnel, and is connected to the inside of the collection box 29 through the injection hole 4 on the injection branch pipe 33, thereby ensuring the balance of pressure inside and outside the collection box 29 and ensuring the reliability of negative pressure gas extraction. During drilling, water and slag flow into the bottom of the collection box 29 through the lower wing pipe 17 and the lower connecting pipe 2 and are deposited. When the first ultrasonic sensor 50 detects that the water-slag has deposited to a certain height, the PLC controller 45 sends an opening signal to the first sewage discharge solenoid valve 48, and the water-slag mixture is discharged from the sewage discharge pipe 31. When the present invention is not in use, the water slag deposited inside the collection box 29 is completely cleaned. The high-pressure water pipe can be connected to the quick-connect connector, and the high-pressure water passes through the balanced air intake pipe 32, the injection main pipe 34 and a plurality of injection branches 33, and finally sprays out through the injection hole 4 on the injection branch 33, and thoroughly cleans the surface of the guide bottom plate 35 laid at the bottom of the collection box 29, and the water slag mixture is discharged through the sewage pipe 31. The guide bottom plate 35 is tilted from the left rear side to the right front side, so as to avoid the formation of dead angles for water slag deposition and help the water slag to be discharged smoothly from the collection box 29.

[0049] The control system mainly uses a PLC controller 45, and is composed of a human-computer interaction display interface, a relay, a digital-to-analog conversion module, an explosion-proof housing, a normally open solenoid valve, a normally closed solenoid valve, a pressure sensor 46, a gas concentration sensor, an ultrasonic sensor, an audio-visual prompt device, and connecting wires. The PLC controller 45 collects and processes information such as pressure, gas concentration, and deposition depth, and controls several solenoid valves to open or close, and performs key actions such as slag removal and gas collection. The audio-visual prompt device can provide some voice prompts based on the construction situation and the working status of the device. Key information can be displayed on the screen through the human-computer interaction interface, making it easy to grasp the data in the drilling construction at any time. The PLC controller 45 can realize automatic control during the spraying, and can also be manually controlled by technicians through a touch screen.

[0050] According to the drilling construction position, drilling rig position, and slag sedimentation storage position, the water slag collector and negative pressure accumulator are reasonably placed so as not to affect the drilling rig construction. Fix the controller in a convenient position for operation, connect the various solenoid valves and sensors on the negative pressure accumulator and water slag collector to the interface position of the controller correctly through wires and convenient plugs according to the instructions, power on self-test, set warning and action parameters, such as the warning readings of the gas sensor 47 and the pressure sensor 46, and the detection readings of the ultrasonic sensor. Select the control type (manual control or automatic control) for use.

[0051] The construction process of the present invention is as follows: after the drill rod is extended into the positioning sleeve 24 and passes through the inner sliding sleeve 25, the center tube and the sealing tube 12, the outer circle of the drill rod and the inner wall clearance of the inner sliding sleeve 25 are matched, the drilling rig is started to start drilling, and at the same time, the exhaust solenoid valve 53 is opened, and the blowout prevention normally closed solenoid valve 52 is closed.

[0052] During the drilling process of rock strata or coal seams with no signs of blowholes, water and slag enter the central tube 15, and due to the existence of gravity, they will enter the collecting box 29 through the lower connecting pipe 2. The gas generated during the drilling process is lighter than air in density, and under the action of negative pressure in the negative pressure accumulator, it will enter the negative pressure box 37 along the drainage pipe 38. Due to the presence of coal slag, a small amount of gas generated in the water-slag collector will enter the negative pressure box 37 through the negative pressure extraction pipe 8 on its upper part. The gas in the negative pressure box 37 finally enters the gas extraction pipeline 10 in the tunnel through the gas discharge pipe 9.

[0053] When the drill rod is drilling upward, there is a small gap (0.1-0.2mm) between the drill rod and the inner sleeve 25. The guide groove on the outer circle of the drill rod cooperates with the guide key 3 on the inner wall of the inner sleeve 25. When the drill rod rotates at high speed, it drives the inner sleeve 25 to rotate inside the sixth flange 23 and through the roller 26. The drill rod is pushed forward along the guide key 3. Due to the negative pressure in the center tube 15, the gas and dust of the inner sleeve 25 will not overflow through the gap. When drilling into the coal seam, a large amount of gas gas generated by gas pressure or hydraulic coal cutting will suddenly spray out along the borehole, which will produce a spray hole. Due to the outflow of a large amount of gas gas during the spray hole, the gas sensor 47 and the pressure sensor 46 will be damaged in a short time. When the value of the monitored signal rises rapidly and reaches the preset threshold, the controller will judge the signal, issue an audible and visual warning, and voice prompt to stop drilling. At the same time, it will send a signal to open the normally closed solenoid valve 52 for preventing blowout. A large amount of coal powder, water and a small amount of gas will enter the collection box 29 through the lower wing pipe 17, and then the gas in the collection box 29 will enter the negative pressure box 37 through the negative pressure extraction pipe 8 and flow into the gas extraction pipeline 10 in the tunnel. At the same time, a large amount of gas and part of the coal powder will directly enter the negative pressure accumulator through the upper wing pipe 16. The gas will finally flow into the gas extraction pipeline 10 in the tunnel, and the coal powder will be deposited in the water at the bottom of the negative pressure box 37 due to gravity. The coal powder is removed and deposited at the bottom of the negative pressure box 37. Until the value of the gas sensor 47 and the value of the pressure sensor 46 are both lower than the set value, the controller will continue to send a signal delay for a certain period of time to continue to control the normally closed solenoid valve 52 for preventing blowout to maintain gas emission. Until the PLC controller 45 voice prompts to start normal drilling. This process can also be controlled manually.

[0054] During the drilling process, the depth of accumulated water and slag in the negative pressure box 37 and the collection box 29 will be detected by the ultrasonic sensor and displayed on the screen of the PLC controller 45. Once the depth of accumulated water and slag in a container reaches the preset value, the PLC controller 45 will issue an audible and visual warning, and a voice prompt: stop drilling, discharge the water slag in the negative pressure accumulator, or prompt: stop drilling, discharge the water slag in the water slag collector. Once the drilling stops, the PLC controller 45 will send a signal to the solenoid valve at the slag discharge port of the water slag collector and the negative pressure accumulator that reaches the specified water and slag height, the first sewage discharge solenoid valve 48 and the second sewage discharge solenoid valve 49 will open, and the water slag will be discharged from the container. After reaching the predetermined discharge height, the PLC controller 45 sends a signal, the first sewage discharge solenoid valve 48 and the second sewage discharge solenoid valve 49 will close, and a voice prompt: the slag discharge is completed, and drilling can continue. This process can also be manually operated on the control system. When the water slag deposited in the negative pressure box 37 is discharged, the PLC controller 45 opens the balancing solenoid valve 54, the pressure inside and outside the negative pressure box 37 is equal, and the water slag in the negative pressure box 37 can be automatically discharged from the negative pressure box 37 under the action of its own gravity.

[0055] Figure 5 The inner diameter of the inner sleeve 25 is shown as Figure 4 The inner diameter of the inner sliding sleeve 25 is different (smaller than). Figure 6 It is shown that the inner hole of the inner sleeve 25 is a triangular prism hole structure (the drill rod during drilling is also a triangular prism structure), and the inner hole wall of the inner sleeve does not need to be provided with a guide key.

[0056] This embodiment does not impose any formal limitation on the shape, material, structure, etc. of the present invention. Any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A blowout prevention hole device for drilling holes in bottom extraction tunnels in coal mines, characterized by: It includes a drilling and expansion section sealing device, a wing-shaped water-slag gas diversion device, a drill pipe sealing guide device, a control system, a negative pressure energy storage device and a water-slag collector; The upper port of the wing-shaped water-slag gas diversion device is connected to the middle port of the drilling expansion section sealing device through a flange, the lower part of the wing-shaped water-slag gas diversion device is connected to the top of the water-slag collector through a lower connecting pipe, the upper part of the wing-shaped water-slag gas diversion device is connected to the negative pressure accumulator through an upper connecting pipe, the drill pipe sealing guide device is arranged at the lower port of the wing-shaped water-slag gas diversion device, the upper part of the water-slag collector is connected to the upper part of the negative pressure accumulator through a negative pressure extraction pipe, the exhaust port of the negative pressure accumulator is connected to the gas extraction pipeline in the tunnel through a gas discharge pipe, and the control system is respectively connected to the wing-shaped water-slag gas diversion device, the water-slag collector and the negative pressure accumulator through control cables; The hole sealing device for the drilling and expanding section includes a hole sealing pipe, a first flange and a second flange, wherein the first flange is coaxially arranged on the outer circle of the hole sealing pipe, the second flange is coaxially arranged on the lower end of the hole sealing pipe, the first flange is located above the second flange, and the distance from the first flange to the second flange is smaller than the distance from the first flange to the upper end of the hole sealing pipe; The wing-shaped water-slag gas diverter comprises a central tube, an upper wing tube, a lower wing tube, a third flange and a fourth flange, the third flange is coaxially arranged at an upper port of the central tube, the fourth flange is coaxially arranged at a lower port of the central tube, the upper ports of the upper wing tube and the lower wing tube are respectively connected to the upper part and the lower part of the central tube, the upper wing tube and the lower wing tube are symmetrically arranged about the center of the central tube, the lower port of the upper wing tube is connected to the upper port of the upper connecting tube through a first pipe joint, and the lower port of the lower wing tube is connected to the upper port of the lower connecting tube through a second pipe joint; The drill pipe sealing guide device comprises a fifth flange, a sixth flange, a positioning sleeve, an inner sleeve and a plurality of rollers. The outer circumference of the fifth flange is provided with a circle of external connection holes corresponding to the fourth flange one by one. The fifth flange and the fourth flange are connected correspondingly by bolt assemblies passing through the external connection holes. The lower surface of the fifth flange is provided with a circle of internal threaded blind holes on the inner side of the external connection holes. The outer circumference of the sixth flange is provided with a circle of internal connection holes corresponding to the internal threaded blind holes one by one. Bolts are inserted into the internal connection holes from bottom to top. The upper part of the bolts is inserted into and threaded into the internal threaded blind holes. The upper end face of the positioning sleeve is coaxially fixedly connected with the lower end face of the sixth flange. The inner diameter of the sixth flange is larger than the inner diameter of the positioning sleeve. The inner sleeve is coaxially arranged inside the sixth flange. A plurality of rollers are rollingly arranged in an annular gap between the outer circle of the inner sleeve and the inner circle of the sixth flange. The center hole of the inner sleeve is circular or triangular matching the cross-sectional shape of the drill pipe. When the center hole of the inner sleeve is circular, the inner circle of the inner sleeve is provided with a guide key along the axial direction, and the outer circle of the drill pipe is provided with a guide groove matching the guide key along the axial direction. The water slag collector comprises a collection box in the shape of a rectangular parallelepiped, a balanced air inlet and a slag inlet pipe joint are arranged on the top of the collection box, an upper part of one side surface of the collection box is connected to the inlet of the negative pressure extraction pipe, the slag inlet pipe joint is connected to the outlet of the lower connecting pipe, and a sewage pipe is arranged at the lower part of one side surface of the collection box; The balanced air inlet is arranged at a left rear corner of the top of the collecting box, and the drain pipe is arranged at a right front corner of the bottom of the collecting box. A balanced air inlet pipe is fixedly arranged in the balanced air inlet, and a quick-plug connector is provided at the upper end of the balanced air inlet pipe. A row of at least three injection branch pipes arranged at intervals from the left rear side to the right front side is laid on the lower surface of the top of the collecting box. Both ends of the injection branch pipes are blocked, and the lower end of the balanced air inlet pipe is connected to all the injection branch pipes through an injection main pipe. The lower part of each injection branch pipe is provided with an injection hole that sprays toward the right front and lower side.

2. The anti-blowout hole device for bottom extraction tunnel drilling construction in coal mine according to claim 1 is characterized by: A material guiding bottom plate which is high from the left rear side to the right front side is laid at the bottom of the collecting box, and the lowest point of the right front side of the material guiding bottom plate is flush with the lower edge of the inner hole of the sewage pipe.

3. The anti-blowout hole device for bottom extraction tunnel drilling construction in coal mine according to claim 1 is characterized by: The negative pressure energy accumulator includes a bracket, on which a negative pressure box is arranged, the upper part of the negative pressure box is a quadrangular prism structure, the lower part of the negative pressure box is a quadrangular pyramid structure which is larger at the top and smaller at the bottom, the top of the negative pressure box is connected to the upper wing pipe by a drainage pipe, a gas inlet pipe joint, a large-diameter inlet pipe joint and a large-diameter outlet pipe joint are arranged on the top of the negative pressure box, the gas inlet pipe joint is connected to the outlet of the negative pressure extraction pipe, the large-diameter inlet pipe joint is connected to the lower port of the upper connecting pipe, the large-diameter outlet pipe joint is connected to the inlet of the gas discharge pipe, and a water slag discharge pipe is arranged at the lower end of the quadrangular pyramid structure of the negative pressure box.

4. The anti-blowout hole device for bottom extraction tunnel drilling construction in coal mine according to claim 3 is characterized by: An inner sleeve is connected to the internal thread of the large-caliber air outlet pipe joint, a filter is fixedly arranged at the lower end of the inner sleeve, and the central hole of the inner sleeve is a hexagonal column structure.

5. The anti-blowout hole device for bottom extraction tunnel drilling construction in coal mine according to claim 3 is characterized by: The control system includes a PLC controller, a pressure sensor, a gas sensor, a first sewage discharge solenoid valve, a second sewage discharge solenoid valve, a first ultrasonic sensor, a second ultrasonic sensor, a blowout prevention normally closed solenoid valve, an exhaust solenoid valve, and a balancing solenoid valve; the pressure sensor and the gas sensor are both arranged on the upper wing pipe, the first sewage discharge solenoid valve is arranged on the sewage discharge pipe, the second sewage discharge solenoid valve is arranged on the water slag discharge pipe, the first ultrasonic sensor is arranged on the top of the collection box to monitor the water slag height in the collection box, the second ultrasonic sensor is arranged on the top of the negative pressure box to monitor the water slag height in the negative pressure box, the blowout prevention normally closed solenoid valve is installed on the large-diameter air inlet pipe joint, the exhaust solenoid valve is installed on the large-diameter air outlet pipe joint, and the balancing solenoid valve is installed on the top of the negative pressure box.

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