Efficient utilization device and method for low-concentration coal mine pump drainage gas

Abstract

The invention provides an efficient utilization device and method for low-concentration coal mine pumped and discharged gas. Relates to the technical field of coal mine gas utilization. The device comprises a mixing tank, a combustion chamber and a water boiling tank, a stirrer is rotatably mounted in the mixing tank, a mounting table is fixedly mounted on the outer wall of the mixing tank, an exhaust fan is fixedly mounted at the top of the mounting table, a gas guide cover is fixedly mounted on an air inlet port of the exhaust fan through a folding pipe, and a gas outlet port of the gas guide cover is fixedly connected with the combustion chamber. A gas inlet cover is arranged on one side of the gas guide cover, a sealing ring is fixedly installed on the side, close to the gas inlet cover, of the gas guide cover, the gas inlet cover is attached to the sealing ring, and a filtering pretreatment assembly is arranged in the gas inlet cover and used for filtering sucked gas. Filtering pretreatment and concentration adjustment can be carried out on low-concentration gas, various negative effects caused by large concentration fluctuation are reduced, and the efficient utilization effect is improved.

Description

Technical Field

[0001] This invention relates to the field of coal mine gas utilization technology, and in particular to a device and method for the efficient utilization of low-concentration coal mine gas extraction. Background Technology

[0002] Coal mine gas is a gas generated during coal mining. Its main component is methane. Methane is a clean energy source, but it is also a greenhouse gas with a greenhouse effect 21 times that of carbon dioxide. Low-concentration methane (methane volume fraction of 5% - 16%) accounts for a large proportion of coal mine methane. Due to its low concentration and poor combustion stability, traditional utilization methods suffer from low efficiency and poor safety, resulting in a large amount of low-concentration coal mine methane being directly released into the atmosphere. This not only wastes valuable energy resources but also causes serious damage to the ecological environment.

[0003] Existing low-concentration coal mine gas extraction and utilization devices mostly adopt direct combustion for power generation or heating. However, due to the lack of a concentration regulation mechanism, the gas concentration fluctuates greatly, which can easily lead to safety hazards such as incomplete combustion, easy flameout, and explosion. In addition, existing devices lack an effective pretreatment mechanism and cannot filter and intercept impurities inside the gas, which further limits the efficient utilization of low-concentration gas.

[0004] Therefore, it is necessary to provide a new device and method for the efficient utilization of low-concentration coal mine gas drainage to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a device and method for efficient utilization of low-concentration coal mine gas extraction, which can perform filtration pretreatment and concentration adjustment of low-concentration gas, reduce various adverse consequences caused by large concentration fluctuations, and improve the efficiency of utilization.

[0006] To solve the above-mentioned technical problems, the present invention provides a high-efficiency utilization device for low-concentration coal mine methane extraction, comprising a mixing tank, a combustion chamber, and a boiling water tank. A stirrer is rotatably installed inside the mixing tank. An installation platform is fixedly installed on the outer wall of the mixing tank. An exhaust fan is fixedly installed on the top of the installation platform. A gas guide hood is fixedly installed on the air inlet port of the exhaust fan via a bend pipe. An air intake hood is provided on one side of the air guide hood, and a sealing ring is fixedly installed on the side of the air guide hood near the air intake hood. The air intake hood fits snugly against the sealing ring. A filter pretreatment component is provided inside the air intake hood for filtering the inhaled methane gas. One end of an exhaust pipe is fixedly installed on the air outlet port of the exhaust fan. The other end of the air pipe is fixedly connected to the top of the mixing tank. An air compressor is installed above the exhaust fan and is fixedly connected to the outer wall of the mixing tank. One end of the air guide pipe is fixedly installed at the outlet end of the air compressor, and the other end of the air guide pipe is fixedly connected to the top of the mixing tank. One end of the guide pipe is fixedly installed on the side of the mixing tank near the combustion chamber, and the other end of the guide pipe is fixedly connected to the combustion chamber. An intake valve is installed on the guide pipe. An igniter is installed in the combustion chamber. The water boiler is fixedly installed on the top of the combustion chamber, and the bottom of the water boiler extends into the combustion chamber. A steam pipe is fixedly installed on the top of the water boiler through three connecting pipes.

[0007] Furthermore, the stirrer includes a stirring rod and multiple stirring blades. The stirring rod is rotatably mounted on the inner top wall of the mixing tank, and the multiple stirring blades are fixedly mounted on the stirring rod. A stirring motor is fixedly mounted on the top of the mixing tank, and the output shaft of the stirring motor is fixedly connected to the top end of the stirring rod. A gas concentration sensor is fixedly mounted on the inner top wall of the mixing tank.

[0008] Furthermore, the air intake hood is fixedly connected to the air guide hood by bolts, the filter pretreatment assembly includes a filter cloth, the filter cloth is fixedly installed inside the air intake hood, a drying box is fixedly installed inside the air intake hood, the drying box is located between the filter cloth and the air guide hood, and multiple air vents are opened on both sides of the drying box, the drying box is filled with dry particles.

[0009] Furthermore, a flame detector is provided in the combustion chamber, and a guide pipe is fixedly installed on the side of the combustion chamber away from the mixing tank. Multiple arc-shaped heat-conducting pipes are fixedly installed on the guide pipe, and the arc-shaped heat-conducting pipes are in contact with the outer wall of the water boiling tank.

[0010] Furthermore, a level gauge is fixedly installed on the top of the water boiling tank, and a water injection pipe is provided on the water boiling tank.

[0011] Furthermore, an external arm is fixedly installed on the mixing tank, the bottom of the air compressor is fixedly connected to the external arm, and a pipe hole is opened on the external arm. The exhaust pipe passes through the pipe hole and does not contact the inner wall of the pipe hole.

[0012] Furthermore, a bearing protrusion is fixedly installed on the mixing tank below the mounting platform. A first cylinder is fixedly installed on the top of the bearing protrusion, and a linkage plate is slidably installed on the top of the bearing protrusion. The output shaft of the first cylinder is fixedly connected to the linkage plate. A steering shaft is rotatably installed on the linkage plate. A connecting bridge is fixedly installed at the end of the steering shaft away from the mixing tank. Dovetail slots are provided at the top and bottom of the connecting bridge, and one side of each dovetail slot is open. A dovetail insert is fixedly installed at the bottom of the air intake hood. The dovetail insert is inserted into the corresponding dovetail slot and is fixedly connected to the corresponding dovetail slot by bolts. A steering motor is fixedly installed on one side of the linkage plate, and the output shaft of the steering motor is fixedly connected to one end of the steering shaft.

[0013] Furthermore, a support platform is fixedly installed on one side of the mixing tank, and two second cylinders are fixedly installed on the top of the support platform. Two isolation covers are slidably installed on the top of the support platform. The output shafts of the two second cylinders are fixedly connected to the two isolation covers respectively. Both isolation covers have clearance openings on their tops, and the two clearance openings form a rectangular clearance passage. The connecting bridge passes through the rectangular clearance passage. Sealing rings are provided on the sides of the two isolation covers that are close to each other. The two sealing rings fit together. Sealing strips are provided in the two clearance openings. The two sealing strips are fixedly connected to the corresponding sealing rings, and the two sealing strips fit together with both sides of the connecting bridge.

[0014] Furthermore, positioning levers are fixedly installed at the top and bottom of the air intake hood, and recessed grooves are formed on the sides of the two positioning levers that are away from each other. Lugs are fixedly installed at the top and bottom of the air guide hood, and positioning slots are formed on the sides of the two lugs that are away from the exhaust fan. The ends of the two positioning levers near the exhaust fan are respectively inserted into the two positioning slots. Insertion strips are slidably installed on the sides of the two lugs that are away from each other, and the sides of the two insertion strips that are close to each other are inserted into the corresponding recessed grooves. Connecting sleeves are fixedly fitted on the two insertion strips, and tension springs are fitted on the two insertion strips. The ends of the tension springs that are close to each other are fixedly connected to the two lugs, and the ends that are far apart from each other are fixedly connected to the two connecting sleeves. Both of the insert strips have right-angle grooves. A mounting bracket is fixedly installed on the mixing tank. The exhaust pipe passes through the mounting bracket. A third cylinder is fixedly installed on the side of the mounting bracket away from the mixing tank. A sliding strip is fixedly installed on the output shaft of the third cylinder. Two wedge-shaped inserts are fixedly installed on the side of the sliding strip away from the mixing tank. The two wedge-shaped inserts are respectively adapted to the two right-angle grooves. The folded pipe on the air inlet port of the exhaust fan passes through the sliding strip and is slidably connected to the sliding strip.

[0015] This invention also provides a method for efficient utilization of low-concentration coal mine methane drainage, comprising the following steps: S1. Gas pretreatment: Gas first enters the intake hood, where the filter cloth can effectively intercept solid particulate impurities in the gas, and the drying particles in the drying box can absorb moisture in the gas, preventing moisture from entering the subsequent system and causing malfunctions or affecting combustion efficiency. S2. Gas and air mixing: The air compressor delivers compressed air to the mixing tank and starts the stirring motor to fully and evenly mix the gas and air to form a stable combustible mixture. S3. Gas Combustion and Thermal Energy Utilization: Open the intake valve on the guide pipe to send the mixed gas into the combustion chamber and start the igniter. The mixed gas generates a flame in the combustion chamber, and the open flame can directly boil the water in the water tank. The water inside gradually heats up, and the high-temperature flue gas generated by combustion is discharged through the guide pipe. During the discharge process, some of the high-temperature flue gas enters the arc-shaped heat conduction pipe and flows, transferring its heat through the pipe wall to the water in the water tank, further realizing the recovery and utilization of thermal energy. The water in the water tank boils and generates steam, which is then transported to the steam pipe and then to external equipment. In addition, the high-temperature flue gas discharged through the guide pipe can also be transported to external equipment for utilization.

[0016] Compared with related technologies, the low-concentration coal mine gas extraction and efficient utilization device and method provided by the present invention have the following beneficial effects: I. This invention uses a filter cloth to intercept solid impurities and dry particles in a drying box to absorb moisture, providing dual protection for the stable operation of the subsequent system and exhibiting high pretreatment capabilities. Second, this invention delivers air through an air compressor and mixes it with a stirrer, combined with real-time monitoring by a gas concentration sensor, to ensure a stable concentration of combustible mixture and improve combustion safety. Third, this invention maximizes the utilization of gas combustion heat by combining the direct-fired water-boiling tank with the recovery of waste heat from flue gas through an arc-shaped heat-conducting pipe. Furthermore, both steam and high-temperature flue gas are utilized as resources, reducing energy waste and environmental pollution. Attached Figure Description

[0017] Figure 1 A three-dimensional structural schematic diagram of the first embodiment of the low-concentration coal mine gas extraction and high-efficiency utilization device provided by the present invention; Figure 2 A schematic diagram of the front view of the first embodiment of the low-concentration coal mine gas extraction and high-efficiency utilization device provided by the present invention; Figure 3 A rear-view perspective schematic diagram of the first embodiment of the low-concentration coal mine gas extraction and high-efficiency utilization device provided by the present invention. Figure 4 A schematic diagram of the assembly structure of the mixing tank, the exhaust fan and the air compressor in the first embodiment of the low-concentration coal mine gas extraction and high-efficiency utilization device provided by the present invention; Figure 5 A cross-sectional view of the mixing tank in the first embodiment of the low-concentration coal mine gas extraction and high-efficiency utilization device provided by the present invention; Figure 6 A schematic diagram of the assembly structure of the gas guide hood and the gas inlet hood in the first embodiment of the low-concentration coal mine gas extraction and high-efficiency utilization device provided by the present invention. Figure 7 A cross-sectional view of the air intake hood in the first embodiment of the low-concentration coal mine gas extraction and high-efficiency utilization device provided by the present invention; Figure 8 A cross-sectional view of the combustion chamber in the first embodiment of the low-concentration coal mine gas extraction and high-efficiency utilization device provided by the present invention; Figure 9 A three-dimensional structural schematic diagram of the second embodiment of the low-concentration coal mine gas extraction and high-efficiency utilization device provided by the present invention; Figure 10 A schematic diagram of the front view of the second embodiment of the low-concentration coal mine gas extraction and high-efficiency utilization device provided by the present invention; Figure 11 A schematic diagram of the disassembled state of the connecting bridge and the air intake hood in the second embodiment of the low-concentration coal mine gas extraction and high-efficiency utilization device provided by the present invention. Figure 12A schematic diagram of the installation of the embedded settling trough in the second embodiment of the low-concentration coal mine gas extraction and high-efficiency utilization device provided by the present invention; Figure 13 A schematic diagram of the connection structure between the wedge-shaped insert and the sliding strip in the second embodiment of the low-concentration coal mine gas extraction and high-efficiency utilization device provided by the present invention; Figure 14 A schematic diagram of the lug structure in the second embodiment of the low-concentration coal mine gas extraction and high-efficiency utilization device provided by the present invention; Figure 15 This is a schematic diagram showing the fitting state of two isolation covers in the second embodiment of the low-concentration coal mine gas extraction and high-efficiency utilization device provided by the present invention.

[0018] The diagram labels are as follows: 1. Mixing tank; 2. Combustion chamber; 3. Boiling water tank; 4. Mounting platform; 5. Exhaust fan; 6. Exhaust pipe; 7. Air compressor; 8. Air guide pipe; 9. Agitator; 10. Gas concentration sensor; 11. Air guide hood; 12. Air inlet hood; 13. Filter cloth; 14. Drying box; 15. Conductive pipe; 16. Igniter; 17. Flame detector; 18. Guide pipe; 19. Arc-shaped heat conduction pipe; 20. Level gauge; 21. Steam pipe; 22. 23. Bearing plate; 24. First cylinder; 25. Linkage plate; 26. Steering shaft; 27. Connecting bridge; 28. Dovetail slot; 29. ​​Dovetail insert; 30. Support platform; 31. Second cylinder; 32. Isolation cover; 33. Positioning folding rod; 34. Insertion groove; 35. Lug; 36. Positioning slot; 37. Insertion strip; 38. Connecting sleeve; 39. Tension spring; 40. Right angle groove; 41. Third cylinder; 42. Sliding strip; 43. Wedge-shaped insert. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] First embodiment: Please refer to the following: Figures 1-8In the first embodiment of the present invention, the low-concentration coal mine gas extraction and high-efficiency utilization device includes: a mixing tank 1, a combustion chamber 2, and a boiling water tank 3. A stirrer 9 is rotatably installed inside the mixing tank 1. The stirrer 9 includes a stirring rod and multiple stirring blades. The stirring rod is rotatably installed on the inner top wall of the mixing tank 1, and the multiple stirring blades are fixedly installed on the stirring rod. Furthermore, a stirring motor is fixedly installed on the top of the mixing tank 1, and its output shaft is fixedly connected to the top end of the stirring rod. A gas concentration sensor 10 is fixedly installed on the inner top wall of the mixing tank 1, which can be used to detect the gas concentration inside the mixing tank 1 in real time. An installation platform 4 is fixedly installed on the outer wall of the mixing tank 1, and an exhaust fan 5 is fixedly installed on its top. A gas guide hood 11 is fixedly installed on the air inlet port of the exhaust fan 5 via a folded pipe. An air inlet hood 12 is fixedly installed on one side of the gas guide hood 11 via bolts, and a sealing ring is fixedly installed on the side of the gas guide hood 11 near the air inlet hood 12. The air inlet hood 12 fits against the sealing ring. The system includes a pre-treatment filter assembly for filtering the inhaled gas. One end of an exhaust pipe 6 is fixedly installed on the outlet port of the exhaust fan 5, and the other end of the exhaust pipe 6 is fixedly connected to the top of the mixing tank 1. An air compressor 7 is located above the exhaust fan 5 and is fixedly connected to the outer wall of the mixing tank 1. One end of a guide pipe 8 is fixedly installed at the outlet of the air compressor 7, and the other end of the guide pipe 8 is fixedly connected to the top of the mixing tank 1. One end of a connecting pipe 15 is fixedly installed on the side of the mixing tank 1 near the combustion chamber 2, and the other end of the connecting pipe 15 is fixedly connected to the combustion chamber 2. An intake valve is installed on the connecting pipe 15, allowing the mixed gas to be smoothly drawn into the combustion chamber 2. Furthermore, an igniter 16 is installed inside the combustion chamber 2 to ignite the mixed gas. A water boiler 3 is fixedly installed on the top of the combustion chamber 2, and the bottom of the water boiler 3 extends into the combustion chamber 2, allowing it to be directly heated by an open flame. A steam pipe 21 is fixedly installed on the top of the water boiler 3 via three connecting pipes.

[0021] The aforementioned filter pretreatment assembly includes a filter cloth 13 and a drying box 14 fixedly installed inside the air intake hood 12. The drying box 14 is located between the filter cloth 13 and the air guide hood 11. Multiple air vents are provided on both sides of the drying box 14. The drying box 14 is filled with dry particles. Through the dual treatment of the filter cloth 13 and the drying box 14, dust and impurities in the inhaled gas are basically filtered out, and the moisture in it can also be basically absorbed.

[0022] In this embodiment, in order to burn the gas, a flame detector 17 is provided in the combustion chamber 2. A guide pipe 18 is fixedly installed on the side of the combustion chamber 2 away from the mixing tank 1. Multiple arc-shaped heat conduction pipes 19 are fixedly installed on the guide pipe 18. The arc-shaped heat conduction pipes 19 are in contact with the outer wall of the water boiling tank 3. The high-temperature flue gas generated during the combustion process can form a heat exchange between the arc-shaped heat conduction pipes 19 and the water boiling tank 3, thereby further improving the waste heat utilization rate. In addition, a level gauge 20 is fixedly installed on the top of the water boiling tank 3 to control the amount of water in the water boiling tank 3. A water injection pipe is provided on the water boiling tank 3 to inject water into the water boiling tank 3.

[0023] In this embodiment, in order to achieve a stable installation of the air compressor 7, an external arm is fixedly installed on the mixing tank 1, the bottom of the air compressor 7 is fixedly connected to the external arm, and a pipe hole is opened on the external arm. The exhaust pipe 6 passes through the pipe hole and does not contact the inner wall of the pipe hole.

[0024] In this embodiment The water inlet pipe is connected to the external water inlet mechanism, and a sufficient amount of water is injected into the boiling water tank 3 in advance. The water volume can be controlled by the level gauge 20. When gas needs to be utilized, the exhaust fan 5 is started first, and gas is drawn in through the air guide hood 11 and the filter pretreatment assembly. The filter pretreatment assembly filters and dries the gas. The filter cloth 13 can effectively intercept solid particulate impurities in the gas, and the drying particles filled in the drying box 14 can absorb moisture in the gas, preventing moisture from entering the subsequent system and causing malfunctions or affecting combustion efficiency. After being pressurized by the exhaust fan 5, the pretreated gas is transported to the mixing tank 1 through the exhaust pipe 6.

[0025] Then, the air compressor 7 delivers compressed air to the mixing tank 1 through the air pipe 8, where it is fully mixed with the gas from the exhaust pipe 6. The stirring motor is then started, and the stirrer 9 inside the mixing tank 1 rotates continuously. Its stirring blades agitate the mixed gas inside the tank, ensuring that the gas and air are fully and evenly mixed to form a stable combustible mixture. The gas concentration sensor 10 at the top of the mixing tank 1 monitors the concentration of the mixed gas inside the tank in real time and feeds back the data for system regulation.

[0026] Once the concentration of the mixed gas in the mixing tank 1 reaches the appropriate combustion standard, the intake valve on the guide pipe 15 is opened to send the combustible mixed gas into the combustion chamber 2, and the igniter 16 is activated. The igniter generates a flame in the combustion chamber 2 to ignite the incoming combustible mixed gas. During the combustion process, the flame detector 17 monitors the combustion status in real time to ensure a stable combustion process.

[0027] Meanwhile, during combustion, the open flame can directly heat the water in the boiling tank 3, gradually raising the temperature of the water inside. The high-temperature flue gas generated by combustion is discharged through the guide pipe 18. During the discharge process, some of the high-temperature flue gas enters the arc-shaped heat-conducting pipe 19 and flows, thereby transferring its heat to the water in the boiling tank 3 through the pipe wall, further realizing the recovery and utilization of heat energy. When the water in the boiling tank 3 boils and generates steam, it is transported to the steam pipe 21 through three connecting pipes, and then transported to external equipment through the steam pipe 21. This external equipment can be used for industrial production, heating, or other occasions that require steam. At the same time, the high-temperature flue gas discharged through the guide pipe 18 can also be used in the applicable occasions.

[0028] Compared with related technologies, the low-concentration coal mine gas extraction and high-efficiency utilization device provided by the present invention has the following beneficial effects: I. This invention uses filter cloth 13 to intercept solid impurities and drying particles in drying box 14 to absorb moisture, providing dual protection for the stable operation of the subsequent system and having a high pretreatment capability. Second, the present invention delivers air through air compressor 7 and mixes it with agitator 9, and monitors it in real time with gas concentration sensor 10 to ensure stable concentration of combustible mixture and improve combustion safety. Third, this invention maximizes the utilization of gas combustion heat by combining the open flame direct-fired water boiling tank 3 with the arc-shaped heat conduction pipe 19 to recover waste heat from flue gas. Furthermore, both steam and high-temperature flue gas are utilized as resources, reducing energy waste and environmental pollution.

[0029] Second embodiment: Based on the efficient utilization device for low-concentration coal mine gas extraction provided in the first embodiment of this application, the second embodiment of this application proposes another efficient utilization device for low-concentration coal mine gas extraction. The second embodiment is merely a preferred embodiment of the first embodiment, and the implementation of the second embodiment will not affect the separate implementation of the first embodiment.

[0030] The second embodiment of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0031] Please refer to the following: Figures 9-15The low-concentration coal mine gas extraction and high-efficiency utilization device also includes a supporting convex plate 22 located below the mounting platform 4. The supporting convex plate 22 is fixedly installed on the mixing tank 1. A first cylinder 23 is fixedly installed on the top of the supporting convex plate 22. A linkage plate 24 is slidably installed on the top of the supporting convex plate 22. This sliding installation is achieved by fixing a first guide rail on the supporting convex plate 22. The first guide rail passes through the linkage plate 24 and is slidably connected to it. The output shaft of the first cylinder 23 is fixedly connected to the linkage plate 24. A rotating part is mounted on the linkage plate 24. A steering shaft 25 is fixedly mounted with a connecting bridge 26 at the end of the steering shaft 25 away from the mixing tank 1. The top and bottom of the connecting bridge 26 are provided with dovetail slots 27, and one side of each of the two dovetail slots 27 is open. A dovetail insert 28 is fixedly mounted at the bottom of the air intake shroud 12. The dovetail insert 28 is inserted into the corresponding dovetail slot 27 and is fixedly connected to the corresponding dovetail slot 27 by bolts. A steering motor is fixedly mounted on one side of the linkage plate 24, and the output shaft of the steering motor is fixedly connected to one end of the steering shaft 25.

[0032] In this embodiment, to provide isolation and protection for the unused air intake hood 12, a support platform 29 is fixedly installed on one side of the mixing tank 1. Two second cylinders 30 are fixedly installed on the top of the support platform 29, and two isolation covers 31 are slidably installed on the top of the support platform 29. This slidable installation is achieved by fixing a second guide rail on the top of the support platform 29. Two sliders are slidably installed on the second guide rail, and the tops of the two sliders are fixedly connected to the two isolation covers 31 respectively. The output shafts of the two second cylinders 30 are fixedly connected to the two isolation covers 31 respectively. Both isolation covers 31 have clearance openings on their tops, and the two clearance openings form a rectangular clearance passage. The connecting bridge 26 passes through the rectangular clearance passage, and sealing rings are provided on the sides of the two isolation covers 31 that are close to each other. The two sealing rings fit together, and sealing strips are provided in the two clearance openings. The two sealing strips are fixedly connected to the corresponding sealing rings, and the two sealing strips fit together on both sides of the connecting bridge 26, thereby ensuring the sealing degree when the two isolation covers 31 are closed.

[0033] In this embodiment, to improve the connection stability between the air intake shroud 12 and the air guide shroud 11, positioning levers 32 are fixedly installed at the top and bottom of the air intake shroud 12. A recessed groove 33 is provided on the side of each positioning lever 32 that is away from each other. Lugs 34 are fixedly installed at the top and bottom of the air guide shroud 11. A positioning slot 35 is provided on the side of each lug 34 that is away from the exhaust fan 5. The ends of the two positioning levers 32 near the exhaust fan 5 are respectively inserted into the two positioning slots 35. A positioning strip 36 is slidably installed on the side of each lug 34 that is away from each other. The sides of the two positioning strips 36 that are close to each other are inserted into the corresponding recessed groove 33. A connecting sleeve 37 is fixedly fitted on each of the two positioning strips 36, and a tension spring 38 is fitted on each of the two positioning strips 36. The ends of the two tension springs 38 that are close to each other are fixedly connected to the two lugs 34, and the ends that are far from each other are fixedly connected to the two connecting sleeves 37. Next, the elastic force provided by the tension spring 38 allows the inserting strip 36 to be stably inserted into the inserting groove 33. In addition, right-angle grooves 39 are provided on both inserting strips 36. A mounting bracket is fixedly installed on the mixing tank 1. The exhaust pipe 6 passes through the mounting bracket. A third cylinder 40 is fixedly installed on the side of the mounting bracket away from the mixing tank 1. A sliding strip 41 is fixedly installed on the output shaft of the third cylinder 40. Two wedge-shaped inserts 42 are fixedly installed on the side of the sliding strip 41 away from the mixing tank 1. The two wedge-shaped inserts 42 are respectively adapted to the two right-angle grooves 39. The folded pipe on the air inlet port of the exhaust fan 5 passes through the sliding strip 41 and slides through the sliding strip 41. The wedge-shaped inserts 42 and the only inclined wall of the right-angle groove 39 form a sliding contact effect, which can push the inserting strip 36 and smoothly bring it out of the inserting groove 33, thereby bringing the positioning folded rod 32 out of the positioning slot 35 to achieve the separation of the air inlet cover 12 and the air guide cover 11.

[0034] In this embodiment There are two intake shrouds 12, one of which is located inside the two isolation shrouds 31 and installed in the dovetail slot 27 at the bottom of the connecting bridge 26. In the initial state, the output shaft of the second cylinder 30 is in the extended state. In subsequent use, in order to quickly replace the filter cloth 13 and the drying box 14 inside the air intake hood 12, the output shafts of the two second cylinders 30 can be retracted first to separate the two isolation covers 31, thereby opening the unused air intake hood 12. Then, the output shaft of the third cylinder 40 is extended to move the wedge-shaped insert 42 toward the right-angle groove 39. When the two contact and form a fit, the two insert strips 36 slide in a straight line away from each other and finally move out of the corresponding insert groove 33. At this time, the tension spring 38 is in a stretched state. Then, the output shaft of the first cylinder 23 extends, and under the drive of the linkage plate 24, the connecting bridge 26 moves the two air intake covers 12 away from the air guide cover 11, and finally brings out the corresponding two positioning levers 32 from the corresponding positioning slots 35. Then, the steering motor is started, and its output shaft drives the steering shaft 25 to rotate. After the two air intake covers 12 rotate 180° and exchange positions, the steering motor is turned off. Then, the output shaft of the first cylinder 23 is started to retract, so that the unused air intake cover 12 fits into the air guide cover 11. At the same time, the two positioning levers 32 on it are inserted into the corresponding positioning slots 35. Then, the output shaft of the third cylinder 40 is started to retract, and the stretched tension spring 38 is automatically pulled back, so that the two insert strips 36 are inserted into the corresponding insert grooves 33, thereby completing the replacement of the air intake cover 12. Then, the gas extraction can continue. Next, the used air intake cover 12 can be replaced. During the operation, simply remove the bolts on the dovetail insert 28 inserted into the dovetail slot 27, and then pull out the dovetail insert 28 along with the air intake cover 12. After that, replace it with a new air intake cover 12 and fix it in place. Then, start the output shafts of the two second cylinders 30 to extend, and use the two isolation covers 31 to isolate and protect the newly replaced air intake cover 12 until the next replacement. This can speed up the replacement speed of the air intake cover 12 and ensure the continuity of gas extraction.

[0035] This invention also provides a method for efficient utilization of low-concentration coal mine methane drainage, comprising the following steps: S1. Gas pretreatment: Gas first enters the intake hood 12, where the filter cloth 13 can effectively intercept solid particulate impurities in the gas, and the drying particles in the drying box 14 can absorb moisture in the gas, preventing moisture from entering the subsequent system and causing malfunctions or affecting combustion efficiency. S2. Gas and air mixing: Air compressor 7 delivers compressed air to mixing tank 1 and starts the stirring motor to fully and evenly mix gas and air to form a stable combustible mixture. S3. Gas Combustion and Thermal Energy Utilization: Open the intake valve on the guide pipe 15 to send the mixed gas into the combustion chamber 2 and start the igniter 16. The mixed gas generates a flame in the combustion chamber 2. The open flame can directly boil the water in the water tank 3, and the water inside gradually heats up. The high-temperature flue gas generated by combustion is discharged through the guide pipe 18. During the discharge process, a part of the high-temperature flue gas enters the arc-shaped heat conduction pipe 19 and flows, transferring its heat through the pipe wall to the water in the water tank 3, further realizing the recovery and utilization of thermal energy. The water in the water tank 3 boils and generates steam, which is transported to the steam pipe 21 and then to external equipment. In addition, the high-temperature flue gas discharged through the guide pipe 18 can also be transported to external equipment for utilization.

[0036] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A low-concentration coal mine gas drainage efficient utilization device, comprising a mixing tank, a combustion chamber and a boiling water tank, characterized in that, The mixing tank is rotatably installed with a stirrer, an installation table is fixedly installed on the outer wall of the mixing tank, an air extractor is fixedly installed on the top of the installation table, an air guide cover is fixedly installed on the air inlet port of the air extractor through a folding pipe, an air inlet cover is arranged on one side of the air guide cover, and a sealing ring is fixedly installed on the side of the air guide cover close to the air inlet cover, the air inlet cover is attached to the sealing ring, a filter pretreatment assembly is arranged in the air inlet cover to filter the inhaled gas, one end of an exhaust pipe is fixedly installed on the air outlet port of the air extractor, the other end of the exhaust pipe is fixedly connected to the top of the mixing tank, an air compressor is arranged above the air extractor, the air compressor is fixedly connected to the outer wall of the mixing tank, one end of an air guide pipe is fixedly installed on the air outlet end of the air compressor, and the other end of the air guide pipe is fixedly connected to the top of the mixing tank. One end of a guide pipe is fixedly installed on the side of the mixing tank close to the combustion chamber, the other end of the guide pipe is fixedly connected to the combustion chamber, an air inlet valve is arranged on the guide pipe, an igniter is arranged in the combustion chamber, and a water boiling tank is fixedly installed on the top of the combustion chamber, and the bottom of the water boiling tank extends into the combustion chamber, and the top of the water boiling tank is fixedly installed with a steam pipe through three connecting pipes.

2. The low-concentration coal mine gas drainage high-efficiency utilization device according to claim 1, characterized in that, The stirrer comprises a stirring rod and a plurality of stirring blades, the stirring rod is rotatably installed on the inner wall of the top of the mixing tank, the plurality of stirring blades are fixedly installed on the stirring rod, a stirring motor is fixedly installed on the top of the mixing tank, the output shaft of the stirring motor is fixedly connected to the top end of the stirring rod, and a gas concentration sensor is fixedly installed on the inner wall of the top of the mixing tank.

3. The low-concentration coal mine gas drainage and efficient utilization device according to claim 2, characterized in that, The air inlet cover is fixedly connected to the air guide cover through bolts, the filter pretreatment assembly comprises filter cloth, the filter cloth is fixedly installed in the air inlet cover, a drying box is fixedly installed in the air inlet cover, the drying box is located between the filter cloth and the air guide cover, a plurality of air permeable holes are formed in the two sides of the drying box, and dry particles are filled in the drying box.

4. The low-concentration coal mine gas drainage high-efficiency utilization device according to claim 3, characterized in that, A flame detector is arranged in the combustion chamber, a guide pipe is fixedly installed on the side of the combustion chamber away from the mixing tank, a plurality of arc-shaped heat pipes are fixedly installed on the guide pipe, and the arc-shaped heat pipes are attached to the outer wall of the water boiling tank.

5. The low-concentration coal mine gas drainage and efficient utilization device according to claim 4, characterized in that, A liquid level meter is fixedly installed on the top of the water boiling tank, and a water filling pipe is arranged on the water boiling tank.

6. The low-concentration coal mine gas drainage and efficient utilization device according to claim 5, characterized in that, An external arm is fixedly installed on the mixing tank, the bottom of the air compressor is fixedly connected to the external arm, a pipe hole is formed in the external arm, and the exhaust pipe penetrates through the pipe hole without contacting the inner wall of the pipe hole.

7. The low-concentration coal mine gas drainage and efficient utilization device according to claim 1, characterized in that, The mixed tank is fixedly installed with a bearing lug below the installation table, a first air cylinder is fixedly installed on the top of the bearing lug, a linkage plate is slidingly installed on the top of the bearing lug, the output shaft of the first air cylinder is fixedly connected with the linkage plate, a steering shaft is rotatably installed on the linkage plate, a connecting bridge is fixedly installed on the end of the steering shaft away from the mixed tank, dovetail insertion grooves are formed in the top and bottom of the connecting bridge, and the two dovetail insertion grooves are both opened on one side, a dovetail insertion block is fixedly installed on the bottom of the air inlet cover, the dovetail insertion block is inserted into the corresponding dovetail insertion groove, and the dovetail insertion block is fixedly connected with the corresponding dovetail insertion groove through bolts, a steering motor is fixedly installed on one side of the linkage plate, and the output shaft of the steering motor is fixedly connected with one end of the steering shaft.

8. The low-concentration coal mine gas drainage high-efficiency utilization device according to claim 7, characterized in that, A support table is fixedly installed on one side of the mixed tank, two second air cylinders are fixedly installed on the top of the support table, two isolation covers are slidingly installed on the top of the support table, the output shafts of the two second air cylinders are respectively fixedly connected with the two isolation covers, the top of each of the two isolation covers is provided with an avoiding opening, and the two avoiding openings form a rectangular avoiding opening, the connecting bridge penetrates through the rectangular avoiding opening, and each of the two isolation covers is provided with a sealing ring on the side close to the other isolation cover, the two sealing rings are in abutment, and each of the two avoiding openings is provided with a sealing strip, each of the two sealing strips is fixedly connected with the corresponding sealing ring, and each of the two sealing strips is in abutment with the connecting bridge on both sides.

9. The low-concentration coal mine gas drainage high-efficiency utilization device according to claim 7, characterized in that, Positioning folding rods are fixedly installed on the top and bottom of the air inlet cover, embedding grooves are formed in the sides of the two positioning folding rods away from each other, lugs are fixedly installed on the top and bottom of the air guide cover, positioning insertion grooves are formed in the sides of the two lugs away from the air blower, the ends of the two positioning folding rods close to the air blower are respectively inserted into the two positioning insertion grooves, embedding strips are slidingly installed on the sides of the two lugs away from each other, the sides of the two embedding strips close to each other are respectively inserted into the corresponding embedding grooves, connecting sleeves are fixedly installed on the two embedding strips, tension springs are installed on the two embedding strips, one end of each of the two tension springs close to each other is fixedly connected with the lug, one end of each of the two tension springs away from each other is fixedly connected with the connecting sleeve, and right-angle grooves are formed in the two embedding strips.

10. The method of using the low-concentration coal mine gas drainage and efficient utilization device according to claim 6, characterized in that, The following steps are included: S1, gas pretreatment: the gas first enters the air inlet cover, the filter cloth therein can effectively intercept solid particle impurities in the gas, and the drying particles in the drying box can absorb moisture in the gas to prevent moisture from entering the subsequent system to cause failure or affect the combustion efficiency; S2, gas and air mixing: air compressor delivers compressed air to the mixing tank, start stirring motor, gas and air fully, evenly mixed, forming a stable concentration of flammable mixture; S3, gas combustion and heat utilization: open the air valve on the guide pipe, send the mixed gas into the combustion chamber, and start the igniter, the mixed gas produces flame in the combustion chamber, the open fire can directly form boiling to the boiling kettle, the water inside gradually warms up, the high temperature flue gas produced by combustion is discharged through the guide pipe, in the process of discharging, a part of the high temperature flue gas enters the arc-shaped heat pipe and flows, and the heat is transmitted to the water in the boiling kettle through the pipe wall, further realizing the recycling of heat energy, the water in the boiling kettle boils to produce steam which is delivered to the steam pipe, and then delivered to the external equipment through the steam pipe, and the high temperature flue gas discharged through the guide pipe can also be delivered to the external equipment for utilization.

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