A smart blowout prevention device for coal mine boreholes

Abstract

This application discloses an intelligent blowout prevention device for coal mine boreholes, belonging to the field of mine gas control technology. The device includes a pipe body, a control box, and a gas-slag separation tank. The pipe body has a drill rod channel, a borehole sealing cover, and an inflatable sealing mechanism. The first interface on the pipe body connects to a gas extraction pipeline, and the second and third interfaces connect to the gas-slag separation tank. The gas-slag separation tank has a double-layer structure with upper and lower chambers. Each chamber has an independent pneumatic valve at its bottom. The second and third interfaces connect to the upper chamber, which also has a fourth interface connecting to the gas extraction pipeline. Based on monitoring sensor signals, the control box controls the drilling rig to stop, closes all pneumatic valves, and inflates the inflatable sealing mechanism when parameters exceed limits, thus completely sealing the entire gas passage. This invention solves the problem of gas leakage during slag removal and achieves rapid and complete sealing of the borehole to the extraction pipeline under abnormal operating conditions, effectively preventing gas blowout accidents.

Description

Technical Field

[0001] The invention relates to the field of coal seam gas control equipment technology, and in particular to an intelligent blowout prevention device for coal mine boreholes. Background Technology

[0002] Gas outbursts are very serious accidents during coal mining. Currently, the main method to remove gas is through drilling to prevent excessive gas pressure. However, drilling is required during the extraction process, which may lead to blowouts and affect operational safety. At present, blowout preventers are mainly used to control the orifice openings.

[0003] In coal mine gas drainage drilling, blowout preventers (BOPs) are crucial for preventing abnormal high-pressure gas outbursts (blowouts). However, existing BOPs still have significant structural and functional defects. First, during slag removal operations, the gas flow channel of existing BOPs is open to the outside, making it highly susceptible to gas leakage into the work area, posing a major safety hazard. Second, during the removal of the drill rod tail end (drill tail removal), the gap between the drill rod and the wellhead sealing structure is prone to forming abnormally high-pressure points due to gas accumulation or pressure fluctuations. Existing devices lack effective means for rapid and targeted pressure relief of localized high pressures, which not only easily leads to the failure of the wellhead sealing structure but also induces gas blowout accidents. These defects severely restrict the safety and efficiency of drilling operations. Summary of the Invention

[0004] The purpose of this invention is to provide an intelligent blowout preventer for coal mine drilling, which solves the problem that gas can easily leak into the working space during the slag removal operation of existing blowout preventers, creating a major safety hazard.

[0005] To achieve the above objectives, the invention adopts the following technical solution: A smart blowout prevention device for coal mine boreholes includes a pipe body, a control box, and a gas-slag separation tank; The pipe body has a drill rod extension channel that runs through the tail end and the front end, so that the drill rod passes through the drill rod extension channel and acts on the coal wall; the front end of the pipe body is provided with an orifice sealing cover, and the rear end is provided with an air-filled sealing mechanism that acts on the drill rod; the pipe body is provided with a first interface to connect to the gas extraction pipeline, and a second interface and a third interface to connect to the gas-slag separation tank respectively. The gas-slag separator has a double-layer structure with an upper chamber and a lower chamber. The bottom of the upper chamber and the bottom of the lower chamber are each equipped with an independently controlled pneumatic valve. The second interface and the third interface are both connected to the upper chamber. The upper chamber is also equipped with a fourth interface that connects to the gas extraction pipeline. The gas-slag separator is equipped with a monitoring sensor. Based on the signals from the monitoring sensors, the control box controls the drilling rig to stop, closes all the pneumatic valves, and inflates the inflatable sealing mechanism when parameters exceed limits, so that the entire gas passage is in a completely closed state.

[0006] Furthermore, the inflatable sealing mechanism includes a support ring fixedly disposed at the rear end of the tube body and an annular airbag disposed within the support ring; the annular airbag is provided with an air inlet connector; the air inlet connector extends outward from the support ring.

[0007] Furthermore, the inner side of the support ring is provided with a clamping groove; the circumferential surface of the annular airbag is provided with a fixing plate; the fixing plate is fixed in the clamping groove.

[0008] Furthermore, the openings of the first and second interfaces face upwards of the pipe body, and the opening of the third interface faces downwards of the pipe body and is connected to the gas-sludge separation tank.

[0009] Furthermore, the upper chamber is also provided with a fifth interface connected to the gas extraction pipe; a first pressure relief bag is provided on the gas flow path of the fifth interface.

[0010] Furthermore, the lower chamber is provided with a sixth interface; a first slag discharge bucket and a second slag discharge bucket are connected in series behind the sixth interface; both the first slag discharge bucket and the second slag discharge bucket are provided with a gas discharge port connected to the gas extraction pipe and a slag discharge pipe for discharging wastewater and waste residue; a second pressure relief bag is provided on the gas flow path of the second slag discharge bucket.

[0011] Furthermore, the upper chamber sidewall is provided with an inclined first guide plate, and the lower chamber is provided with a funnel-shaped second guide plate.

[0012] Furthermore, the monitoring sensors include a temperature sensor, a pressure sensor, a carbon monoxide sensor, a methane alarm sensor, and an audible and visual alarm connected to the control box; the temperature sensor is located on the pipe body, the pressure sensor and the carbon monoxide sensor are located above the gas-sludge separation tank, and the methane alarm sensor and the audible and visual alarm are located on the side of the gas-sludge separation tank.

[0013] Furthermore, the top of the gas-slag separation tank is also equipped with a water spray solenoid valve, which is connected to the control box.

[0014] Furthermore, an air inlet gate valve and a rear water braid are provided at the rear of the pipe body; the air inlet gate valve is used to provide compressed air to the drill pipe, and the rear water braid is used to transmit power and supply water to the drill pipe.

[0015] Compared with existing technologies, the beneficial effects of the invention are: 1. Its core beneficial effect lies in effectively solving the key problem of gas leakage during the slag discharge process and achieving a rapid and fully sealed state, effectively preventing the gas injection hole from exceeding its lifespan during drilling.

[0016] 2. This device adopts a double-layer gas-slag separation tank. The mixture containing gas and coal slag first enters the upper chamber. The coal slag settles under gravity. Then, it can be discharged from the upper chamber to the lower chamber through separate pneumatic valves in the upper and lower chambers. The two valves are opened and closed alternately to allow the coal slag in the upper chamber to be discharged from the lower chamber first and then discharged from the lower chamber. During the slag discharge operation, only the pneumatic valve at the bottom of the lower chamber is opened to discharge the coal slag. At the same time, the pneumatic valve at the bottom of the upper chamber remains closed to ensure that the gas extraction passage in the upper chamber is always completely sealed and isolated from the atmosphere. This completely solves the leakage risk caused by the forced opening of the gas passage during the slag discharge of existing blowout preventers.

[0017] 3. The pressure relief valve design on the first interface of the pipe body can perform controlled pressure relief when the pressure near the borehole is too high, safely guiding the gas to the gas extraction pipeline. While releasing pressure, it maintains the airtightness of the main body of the system. Specifically, during the unloading of the drill tail, when abnormal high pressure occurs in the core area of ​​the borehole through which the drill rod passes, it can directly and promptly relieve pressure. This can quickly release the locally accumulated pressure peak, effectively protect the borehole sealing structure and prevent its failure, and effectively prevent the gas leakage from exceeding the limit during the unloading of the drill tail.

[0018] 4. When the sensor detects that the gas concentration, carbon monoxide, temperature or pressure exceeds the limit, the PLC control box will simultaneously instruct the drilling rig to stop, close the pneumatic valve in the lower chamber (while ensuring that the valve in the upper chamber is closed), and cause the air-filled sealing mechanism acting on the drill rod to expand and tighten the seal, instantly achieving a full-range seal from the borehole to the gas drainage pipeline, effectively preventing blowout accidents. Attached Figure Description

[0019] The invention will be further described below with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the overall structure of an intelligent blowout prevention device for coal mine drilling according to the present invention. Figure 2 This is a schematic diagram showing the connection between the gas-slag separation tank, the first slag discharge bucket, and the second slag discharge bucket of the present invention. Figure 3 This is a schematic diagram of the gas-slag separator of the present invention; Figure 4 This is a schematic diagram of the upper and lower chambers of the gas-sludge separator of the present invention; Figure 5 This is a schematic diagram of the overall structure of the tube body of the present invention; Figure 6 This is a schematic diagram of the internal structure of the inflatable sealing mechanism of the present invention; Figure 7This is a schematic diagram of the support ring and air intake connector of the present invention; Figure 8 This is a schematic diagram of the structure of the annular airbag of the present invention.

[0020] Attached reference numerals: 2 Pipe body, 21 First interface, 211 Pressure relief valve, 22 Second interface, 23 Third interface, 3 Gas-slag separator, 31 Upper chamber, 311 First guide plate, 312 First pneumatic butterfly valve, 313 Slag receiving bucket, 32 Lower chamber, 321 Second guide plate, 322 Second pneumatic butterfly valve, 33 Tank body, 34 Fourth interface, 35 Fifth interface, 36 Sixth interface, 361 First slag discharge bucket, 362 Second slag discharge bucket, 363 Gas emission port, 3 64 Slag discharge pipe, 365 Second pressure relief bag, 37 First pressure relief bag, 4 Orifice sealing cover, 5 Inflatable sealing mechanism, 51 Support ring, 511 Clamping groove, 52 Annular airbag, 521 Fixing plate, 53 Air inlet connector, 6-PLC control box, 61 Temperature sensor, 62 Pressure sensor, 63 Carbon monoxide sensor, 64 Methane alarm sensor, 65 Audible and visual alarm, 7 Water spray solenoid valve, 8 Air inlet gate valve, 9 Rear water braid, 10 Gas extraction pipe. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the invention clearer, the technical solutions of the embodiments of the invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the invention, and not all embodiments.

[0022] The technical solution of the invention will be described in detail below with specific embodiments. The following specific embodiments can be combined or substituted with each other according to the actual situation, and the same or similar concepts or processes may not be described again in some embodiments.

[0023] like Figures 1 to 8As shown, the invention provides an intelligent blowout prevention device for coal mine drilling, including a pipe body 2, a gas-slag separation tank 3, and a gas extraction pipeline 10. The gas extraction pipeline 10 is made of DN150 seamless steel pipe, installed along the roadway wall, and the end of the pipeline is connected to the negative pressure system of the surface gas drainage pumping station (vacuum pump power ≥200kW), forming a constant negative pressure of -20kPa to -50kPa in the pipeline to achieve active suction. The pipe body 2 and the coal mine drilling rig are either an integrated structure or a detachable structure. The pipe body 2 has a drill rod extension channel that runs through the tail end and the front end, through which the drill rod acts on the coal wall. On both sides of the drill rod extension channel, there are a first interface 21, a second interface 22, and a third interface 23 connecting the extension channel. A steel pipe is connected to the gas extraction pipeline 10 at the first interface 21. A pressure relief valve 211 is provided at the first interface 21, which is closed under safe conditions. The second interface 22 and the third interface 23 are respectively connected to the upper chamber 31 of the gas-slag separator 3 through steel pipes. An orifice sealing cover 4 is provided at the front end of the pipe body 2. The orifice sealing cover 4 is a corrugated trumpet-shaped structure that can be compressed and fitted to the coal wall along the axial direction, which can effectively prevent the leakage of wastewater, waste residue and gas.

[0024] The gas-ash separation tank 3 includes a tank body 33, which has a double-layer structure of an upper chamber 31 and a lower chamber 32. The bottom of the upper chamber 31 and the bottom of the lower chamber 32 are respectively equipped with independently controlled first pneumatic butterfly valves 312 and 322. The upper chamber 31 also has a fourth interface 34 connecting to the gas extraction pipeline 10. Monitoring sensors are installed inside the gas-ash separation tank 3.

[0025] To ensure the drill pipe can be inserted into the blowout preventer (BOP), a gap must be maintained between the rotating drill pipe and the BOP. Since gas can easily escape through this gap in the event of a gas eruption, an inflatable sealing mechanism 5 is designed at the rear end of the pipe body 2. The inflatable sealing mechanism 5 includes a support ring 51 and an annular air bladder 52 located within the support ring 51. The support ring 51 has an air inlet hole; the annular air bladder 52 has an air inlet connector 53 located within the air inlet hole. The support ring 51 is a pipe of the same size as the extension channel of the pipe body 2, fixed to the rear of the pipe body 2 by a flange. The air inlet connector 53 of the annular air bladder 52 can extend out of or be housed within the air inlet hole and is connected to an external air source. When the monitoring sensor detects that any parameter such as gas concentration, carbon monoxide, temperature, or pressure exceeds the limit, an external gas source injects gas into the annular air bladder 52, causing the annular air bladder 52 to expand. The expanded annular air bladder 52 will grip the drill rod and seal the drill rod axis. This ensures that the drill rod is gripped and stops rotating quickly, and also achieves the sealing function, effectively preventing gas from leaking from the circumferential axis of the drill rod.

[0026] To ensure the airbag retracts radially upon deflation and to prevent the annular airbag 52 from interfering with the rotation of the drill rod during drilling, a clamping groove 511 is provided inside the support ring 51. The clamping groove 511 is formed by two circular steel plates coaxially welded to the support ring 51, with a certain distance maintained between the two plates. Screw holes are made on one or both circular steel plates. A fixing plate 521 is provided on the circumference of the annular airbag 52, extending radially outward. The fixing plate 521 is inserted into the clamping groove 511. Screw holes can be made on the fixing plate 521, passing through both sides. Bolts are passed through the screw holes on one side of the circular steel plate and through the screw holes on the annular airbag 52, and then nuts are used to secure the bolts to the other side of the circular steel plate, thus fixing the fixing plate 521 inside the support ring 51 and achieving a fixed connection between the annular airbag 52 and the support ring 51. By connecting the fixed plate 521 to the support ring 51, the annular airbag 52 can be radially retracted when it deflates. The inner hole of the radially retracted annular airbag 52 will be concentric with the drill rod, ensuring that the annular airbag 52 will not interfere with the rotation of the drill rod.

[0027] The working process of this intelligent blowout prevention device for coal mine drilling is as follows: The front end of the drill rod acts on the coal wall, and the front end of the pipe body 2 abuts against the drill hole drilled by the drill rod. The hole sealing cover 4 fits against the coal wall, and the air-filled sealing mechanism 5 is in a depressurized state during drilling. The gas-containing coal slag mixture generated during drilling enters the second interface 22 and the third interface 23 through the extension channel of the pipe body 2, and then enters the upper chamber 31 of the gas-slag separation tank 3 through the steel pipe. After the coal slag in the gas-slag mixture settles in the upper chamber 31, the gas is extracted from the gas-slag separation tank 3 through the fourth interface 34. At this time, gas-slag separation is achieved. When there is too much coal slag settling in the upper chamber 31, the first pneumatic butterfly valve 312 at the bottom of the upper chamber 31 is opened to let the coal slag fall into the lower chamber 32. At this time, the second pneumatic butterfly valve 322 of the lower chamber 32 is closed. After the coal slag in the upper chamber 31 is completely discharged, the first pneumatic butterfly valve 312 of the upper chamber 31 is closed, and the second pneumatic butterfly valve 322 of the lower chamber 32 is opened, thereby discharging the coal slag from the gas-slag separation tank 3. The separated gas is then transported to the ground extraction pumping station through the fourth port 34 at the top of the upper chamber 31 under the negative pressure of the gas extraction pipeline 10.

[0028] During drilling, when the monitoring sensor detects that any parameter such as gas concentration, carbon monoxide, temperature, or pressure exceeds the limit, the PLC control box 6 simultaneously executes a three-linkage operation: immediately cutting off the power supply to the drilling rig and stopping the machine, closing the first pneumatic butterfly valve 312 of the upper chamber 31 to block the slag discharge channel, and causing the air-filled sealing mechanism 5 to expand and lock the drill rod. This instantly achieves a seal from the borehole opening → pipe body 2 → bottom of the upper chamber 31 of the separation tank, ensuring that gas can only be extracted through the gas extraction pipe 10 and will not leak from the slag discharge port of the gas-slag separation tank 3, the front end of the borehole opening, the tail end of the drill rod, and the five-way sealed tank body. This achieves a sealed state for all channels and effectively prevents the danger of gas ejection during drilling.

[0029] To achieve preliminary separation of gas and slag on the pipe body 2, the openings of the first interface 21 and the second interface 22 face upwards on the pipe body 2, filtering out large pieces of coal slag and providing a smooth flow channel for gas. The opening of the third interface 23 faces downwards on the pipe body 2 and connects to the gas-slag separation tank 3. Utilizing gravity, large pieces of coal slag slide directly into the gas-slag separation tank 3 through the third interface 23, preventing coal slag accumulation within the pipe body. The third interface 23 contains both large pieces of coal slag and gas flowing together. This mixed flow can cause gas to be obstructed in the flow path connected to the third interface 23, leading to gas accumulation due to poor flowability. In this invention, the design of the second interface 22 reduces the amount of gas flowing into the third interface 23, and simultaneously prevents large pieces of coal slag from existing in the pipe of the second interface 22, effectively solving the risk of gas accumulation in the flow path connected to the third interface 23.

[0030] To ensure complete isolation between the subsequent discharge of coal slag and the flow path of gas, the second interface 22 and the third interface 23 are connected to the upper chamber 31 of the gas-slag separator 3. When the lower chamber 32 discharges slag, the first pneumatic butterfly valve 312 at the bottom of the upper chamber 31 is in the closed state, which realizes complete isolation between the gas flow path and the slag discharge channel, effectively preventing the danger of gas ejection during the slag discharge process.

[0031] To further reduce the gas concentration and internal pressure inside the gas-slag separator 3, a fifth interface 35 is connected to the upper chamber 31 of the gas-slag separator 3. The fifth interface 35 is directly connected to the gas extraction pipeline 10 via a steel pipe, allowing the gas entering the gas-slag separator 3 to be diverted into the gas extraction pipeline 10 through the fifth interface 35. This effectively reduces the pressure at a single interface. Simultaneously, a first pressure relief bag 37 is installed along the flow path of the fifth interface 35. The first pressure relief bag 37 automatically expands and releases pressure when the gas pressure exceeds the limit, improving the pressure stabilization capability of the entire pipeline. Furthermore, the lower chamber 32 of the gas-slag separator 3 is provided with a sixth interface 36. A first slag discharge bucket 361 and a second slag discharge bucket 362 are connected in series after the sixth interface 36. Both the first slag discharge bucket 361 and the second slag discharge bucket 362 are provided with a gas discharge port 363 connecting to the gas extraction pipe 10 and a slag discharge pipe 364 for discharging wastewater and slag. A second pressure relief bag 365 is provided on the gas flow path of the second slag discharge bucket 362. When coal slag is discharged from the first pneumatic butterfly valve 312 of the upper chamber 31 to the lower chamber 32, the second pneumatic butterfly valve 322 at the bottom of the lower chamber 32 remains closed. The sixth interface 36 is used to extract the gas in the lower chamber 32 and send it into the first slag discharge bucket 361 or the second slag discharge bucket 362. The gas is then discharged into the gas extraction pipeline 10 through the gas discharge ports 363 on the first and second slag discharge buckets 361 and 362. During this process, the slag discharge pipelines 364 of the first and second slag discharge buckets 361 and 362 are closed, leaving only a connection to the gas extraction pipeline 10. The second pressure relief bag 365 works in conjunction with the first pressure relief bag 37 to implement secondary pressure stabilization protection. The two slag discharge buckets in this design serve to purify the gas, further separating residual coal dust and gas. Valves are installed on the slag discharge pipelines 364 of the first and second slag discharge buckets 361 and 362, which can be automatically controlled by the PLC control box 6 or opened manually.

[0032] To improve the flowability of coal slag within the gas-slag separator 3, both the first pneumatic butterfly valve 312 at the bottom of the upper chamber 31 and the second pneumatic butterfly valve 322 at the bottom of the lower chamber 32 adopt a structure including a valve body, a butterfly plate, and a pneumatic actuator. The pneumatic actuator is connected to the PLC control box 6 via an air pipe to receive action commands. The first guide plate 311 on the side wall of the upper chamber 31 has an eccentric cone structure and is fixed to the side wall by welding. Its lower end extends above the valve body of the first pneumatic butterfly valve 312, guiding the gas-slag mixture in the upper chamber 31 to slide downwards along the plate surface to the first pneumatic butterfly valve 312, preventing accumulation. The eccentric cone structure of the first guide plate 311 allows the pneumatic actuator of the first pneumatic butterfly valve 312 to be designed on the outside of the gas-slag separator 3, facilitating maintenance and parameter adjustment. The second guide plate 321 of the lower chamber 32 has a funnel-shaped structure and is made of stainless steel plates. The small opening of the funnel is directly opposite the inlet of the second pneumatic butterfly valve 322, which can concentrate the residue in the lower chamber 32 and guide it to the second pneumatic butterfly valve 322 for easy and rapid discharge to the slag receiving bucket 313.

[0033] To improve the accuracy of monitoring key safety parameters such as temperature, tank pressure, carbon monoxide concentration, and methane concentration in the blowout preventer and to provide early warning of potential risks, a PT100 temperature sensor 61 is installed and fixed to the outer wall of the pipe body 2 via a threaded interface to monitor the pipe body temperature in real time. A pressure sensor 62 (MPX series sensor) and a carbon monoxide sensor 63 (MQ-7 type sensor) are installed on the top of the gas-sludge separation tank 3 via brackets to monitor the gas pressure and carbon monoxide concentration in the tank, respectively. A methane alarm sensor 64 (JCB4 type) and an audible and visual alarm 65 (using a red warning light and a buzzer) are installed and fixed to the side of the gas-sludge separation tank 3 with bolts. When the methane concentration exceeds the standard, the methane alarm sensor 64 transmits a signal to the PLC, and the PLC immediately triggers the audible and visual alarm 65 to emit a flashing light and an alarm sound of more than 80 decibels.

[0034] The industrial control process of PLC control box 6 is as follows: First, each monitoring sensor collects data in real time and transmits it to PLC control box 6. Among them, temperature sensor 61 detects the temperature of tube 2, pressure sensor 62 and carbon monoxide sensor 63 monitor the gas pressure and carbon monoxide concentration in upper chamber 31, and methane alarm sensor 64 monitors the methane concentration in upper chamber 31. After receiving these data, PLC control box 6 analyzes and judges them. When excessive temperature, excessive air pressure, excessive carbon monoxide concentration, or excessive methane concentration is detected, corresponding actions are immediately triggered. On the one hand, the audible and visual alarm 65 is activated to issue a warning signal. On the other hand, the water spray solenoid valve 7 on the top of the gas-sludge separation tank 3 is opened to spray water into the tank to cool down, reduce dust, or inhibit the diffusion of harmful gases. At the same time, the PLC control box issues opening or closing commands to the first pneumatic butterfly valve 312 and the second pneumatic butterfly valve 322 according to the gas-sludge separation situation. The residue in the upper chamber 31 is guided to the first pneumatic butterfly valve 312 by the first guide plate 311, and the residue in the lower chamber 32 is concentrated to the second pneumatic butterfly valve 322 by the second guide plate 321. The orderly discharge of gas and sludge is achieved through the action of the butterfly valve. When the parameters detected by each sensor return to normal, the PLC control box 6 will control the water spray solenoid valve 7 to close, the audible and visual alarm 65 to stop working, and adjust the status of the first and second pneumatic butterfly valves according to the actual situation to ensure the continuous and stable operation of the device.

[0035] An air inlet gate valve 8 and a rear water braid 9 are also provided behind the pipe body 2. The rear water braid 9 is installed at the tail end of the support ring 51 and directly connected to the drill pipe. The common structure is a cylindrical / box-shaped structure with a rotary seal. The air inlet gate valve 8 is connected to the rear water braid 9 and is usually located to the side or rear of the rear water braid 9. The two ends of the air inlet gate valve 8 are respectively connected to the air inlet pipe and the hose leading to the rear water braid 9 / drill pipe. The compressed air output by the air inlet gate valve 8 is input into the air inlet of the rear water braid 9 through the hose to realize the coordinated operation of air and water. In underground coal mines, dust explosions and gas explosions are deadly risks. Wet dust removal (relying on water supply from the rear water braid 9) and gas slag removal (relying on air supply from the air inlet gate valve 8) are indispensable safety measures. The aforementioned air inlet gate valve 8 and rear water braid 9 are existing and mature equipment in existing wet drilling process equipment, and will not be described in detail in this invention.

[0036] Compared with existing technologies, the beneficial effects of the invention are: 1. Its core beneficial effect lies in effectively solving the key problem of gas leakage during the slag discharge process and achieving a rapid and fully sealed state, effectively preventing the gas injection hole from exceeding its lifespan during drilling.

[0037] 2. This device adopts a double-layer gas-slag separation tank. The mixture containing gas and coal slag first enters the upper chamber. The coal slag settles under gravity. Then, it can be discharged from the upper chamber to the lower chamber through separate pneumatic valves in the upper and lower chambers. The two valves are opened and closed alternately to allow the coal slag in the upper chamber to be discharged from the lower chamber first and then discharged from the lower chamber. During the slag discharge operation, only the pneumatic valve at the bottom of the lower chamber is opened to discharge the coal slag. At the same time, the pneumatic valve at the bottom of the upper chamber remains closed to ensure that the gas extraction passage in the upper chamber is always completely sealed and isolated from the atmosphere. This completely solves the leakage risk caused by the forced opening of the gas passage during the slag discharge of existing blowout preventers.

[0038] 3. The pressure relief valve design on the first interface of the pipe body can perform controlled pressure relief when the pressure near the borehole is too high, safely guiding the gas to the gas extraction pipeline. While releasing pressure, it maintains the airtightness of the main body of the system. Specifically, during the unloading of the drill tail, when abnormal high pressure occurs in the core area of ​​the borehole through which the drill rod passes, it can directly and promptly relieve pressure. This can quickly release the locally accumulated pressure peak, effectively protect the borehole sealing structure and prevent its failure, and effectively prevent the gas leakage from exceeding the limit during the unloading of the drill tail.

[0039] 4. When the sensor detects that the gas concentration, carbon monoxide, temperature or pressure exceeds the limit, the PLC control box will simultaneously instruct the drilling rig to stop, close the pneumatic valve in the lower chamber (while ensuring that the valve in the upper chamber is closed), and cause the air-filled sealing mechanism acting on the drill rod to expand and tighten the seal, instantly achieving a full-range seal from the borehole to the gas drainage pipeline, effectively preventing blowout accidents.

[0040] This application discloses an intelligent blowout prevention device for coal mine boreholes, belonging to the field of mine gas control technology. The device includes a pipe body, a control box, and a gas-slag separation tank. The pipe body has a drill rod channel, a borehole sealing cover, and an inflatable sealing mechanism. The first interface on the pipe body connects to a gas extraction pipeline, and the second and third interfaces connect to the gas-slag separation tank. The gas-slag separation tank has a double-layer structure with upper and lower chambers. Each chamber has an independent pneumatic valve at its bottom. The second and third interfaces connect to the upper chamber, which also has a fourth interface connecting to the gas extraction pipeline. Based on monitoring sensor signals, the control box controls the drilling rig to stop, closes all pneumatic valves, and inflates the inflatable sealing mechanism when parameters exceed limits, thus completely sealing the entire gas passage. This invention solves the problem of gas leakage during slag removal and achieves rapid and complete sealing of the borehole to the extraction pipeline under abnormal operating conditions, effectively preventing gas blowout accidents.

[0041] In addition to the preferred embodiments described above, the present invention has other embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection claimed by the present invention.

Claims

1. A smart blowout prevention device for coal mine boreholes, characterized in that, Includes pipe body (2), control box and gas-slag separation tank (3); The pipe body (2) has a drill rod extension channel that runs through the tail end and the front end, so that the drill rod passes through the drill rod extension channel and acts on the coal wall; the front end of the pipe body (2) is provided with an orifice sealing cover (4), and the rear end is provided with an air-filled sealing mechanism (5) that acts on the drill rod; the pipe body (2) is provided with a first interface (21) to connect to the gas extraction pipe (10), and a second interface (22) and a third interface (23) to connect to the gas-slag separation tank (3) respectively. The gas-slag separator (3) has a double-layer structure with an upper chamber (31) and a lower chamber (32). The bottom of the upper chamber (31) and the bottom of the lower chamber (32) are each equipped with an independently controlled pneumatic valve. The second interface (22) and the third interface (23) are both connected to the upper chamber (31). The upper chamber (31) is also equipped with a fourth interface (34) that connects to the gas extraction pipeline (10). The gas-slag separator (3) is equipped with a monitoring sensor. The control box controls the drilling rig to stop, closes all the pneumatic valves, and inflates the inflatable sealing mechanism (5) when the parameters exceed the limit, based on the signal from the monitoring sensor, so that the entire gas passage is in a fully enclosed state.

2. The intelligent blowout prevention device for coal mine boreholes according to claim 1, characterized in that, The inflatable sealing mechanism (5) includes a support ring (51) fixedly disposed at the rear end of the tube body (2) and an annular airbag (52) disposed within the support ring (51); the annular airbag (52) is provided with an air inlet connector (53); the air inlet connector (53) extends out of the outside of the support ring (51).

3. The intelligent blowout prevention device for coal mine boreholes according to claim 2, characterized in that, The inner side of the support ring (51) is provided with a clamping groove (511); the circumference of the annular airbag (52) is provided with a fixing plate (521); the fixing plate (521) is fixed in the clamping groove (511).

4. The intelligent blowout prevention device for coal mine boreholes according to claim 1, characterized in that, The openings of the first interface (21) and the second interface (22) face upwards from the tube body (2), and the opening of the third interface (23) faces downwards from the tube body (2) and is connected to the gas-sludge separator (3).

5. The intelligent blowout prevention device for coal mine boreholes according to claim 1, characterized in that, The upper chamber (31) is also provided with a fifth interface (35) that connects to the gas extraction pipe (10); a first pressure relief bag (37) is provided on the gas flow path of the fifth interface (35).

6. The intelligent blowout prevention device for coal mine boreholes according to claim 1, characterized in that, The lower chamber (32) is provided with a sixth interface (36); a first slag discharge bucket (361) and a second slag discharge bucket (362) are connected in series behind the sixth interface (36); the first slag discharge bucket (361) and the second slag discharge bucket (362) are both provided with a gas discharge port (363) connected to the gas extraction pipe (10) and a slag discharge pipe (364) for discharging wastewater and waste residue; a second pressure relief bag (365) is provided on the gas flow path of the second slag discharge bucket (362).

7. The intelligent blowout prevention device for coal mine boreholes according to claim 1, characterized in that, The upper chamber (31) has an inclined first guide plate (311) on its side wall, and the lower chamber (32) has a funnel-shaped second guide plate (321).

8. The intelligent blowout prevention device for coal mine boreholes according to claim 1, characterized in that, The monitoring sensors include a temperature sensor (61), a pressure sensor (62), a carbon monoxide sensor (63), a methane alarm sensor (64), and an audible and visual alarm (65) connected to the control box; the temperature sensor (61) is located on the pipe body (2), the pressure sensor (62) and the carbon monoxide sensor (63) are located above the gas-sludge separation tank (3), and the methane alarm sensor (64) and the audible and visual alarm (65) are located on the side of the gas-sludge separation tank (3).

9. The intelligent blowout prevention device for coal mine boreholes according to claim 1, characterized in that, The top of the gas-slag separation tank (3) is also equipped with a water spray solenoid valve (7), which is connected to the control box.

10. The intelligent blowout prevention device for coal mine boreholes according to claim 1, characterized in that, The pipe body (2) is also provided with an air inlet gate valve (8) and a rear water braid (9) at the rear; the air inlet gate valve (8) is used to provide compressed air to the drill pipe, and the rear water braid (9) is used to transmit power and supply water to the drill pipe.

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