Automatic drainage system for preventing spontaneous combustion and blockage in goaf areas

Abstract

This invention relates to the field of coal mine safety engineering technology, and discloses an automatic drainage system for preventing spontaneous combustion and blockage in goaf areas. The system includes an isolation wall assembly located between the floor and roof slabs at the stop-mining line; a drainage pipe assembly runs through the interior of the isolation wall assembly; the isolation wall assembly, extending outwards from the goaf, includes an inner filter wall, a central sealed wall, and an outer sealed wall; the inner filter wall contains at least one baffle, and multiple baffles are connected by adjusting rods; a primary filtration chamber is formed between the inner filter wall and the central sealed wall to reduce water flow velocity and settle sediment. This invention solves the problems of existing goaf drainage pipes being easily blocked by coal slime and gangue, leading to poor drainage, and the problem of fresh air from the roadway side flowing back into the goaf through the drainage pipes when drainage stops or due to negative pressure in the goaf, thus inducing spontaneous combustion of residual coal.

Description

Technical Field

[0001] This invention relates to the field of coal mine safety engineering technology, specifically to an automatic drainage system for preventing spontaneous combustion and blockage in goaf areas. Background Technology

[0002] During underground coal mining operations, as the working face advances, water accumulation inevitably forms in low-lying areas of the goaf. This is especially true in mines with complex geological conditions, fractured roofs, or muddy floors, where the goaf water often exhibits high sand content and high coal slime concentration. To prevent the water from spreading and affecting safe mine production, constructing isolation walls and pre-burying drainage pipes at the stop-mining line is the standard procedure for draining goaf water. This drainage facility not only serves to drain water from the goaf but also acts as a crucial barrier separating the internal environment of the goaf from the external environment of the roadways. Its operational status directly affects the mine's water hazard prevention and fire safety.

[0003] Existing goaf drainage devices primarily achieve this by directly inserting steel pipes into the sealed wall, with a metal filter screen or grid welded and fixed at the pipe opening on the goaf side as a primary filtration structure. Accumulated water, under hydrostatic pressure, passes through the filter screen into the pipe and is eventually discharged into a ditch on the side of the roadway. This structure relies on the filter screen's pore size to passively intercept coal and gangue in the water, thus protecting the unobstructed flow within the pipeline.

[0004] However, on the one hand, existing fixed filter structures, during long-term operation, become tightly coated with a large amount of viscous coal slurry and gravel, forming a dense mud cake. This causes the flow area to decrease rapidly until it becomes completely blocked, and the filter end located inside the closed goaf cannot be manually cleaned or mechanically dredged. On the other hand, a large number of fine, high-sand-content particles, after passing through the filter screen, easily settle and accumulate inside the straight-through pipe, causing secondary blockage inside the pipe, ultimately leading to irreversible failure of the drainage system and loss of control over the water level in the goaf. At the same time, when there is no water flow or when negative pressure is generated inside the goaf due to gas contraction, the straight-through drainage pipe becomes an air leakage channel connecting the roadway and the goaf. Fresh air rich in oxygen from the roadway side flows back into the deep goaf under the pressure difference through the drainage pipe. The continuous oxygen supply accelerates the oxidation and exothermic process of the residual coal in the goaf, easily causing coal spontaneous combustion disasters. Therefore, this invention proposes an automatic drainage system for preventing spontaneous combustion and blockage in the goaf by preventing air ingress in the goaf, in order to solve the shortcomings of the existing technology. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an automatic drainage system for preventing spontaneous combustion and blockage in goaf areas. It solves the problems of existing goaf drainage pipes being easily blocked by coal slime and gangue, leading to poor drainage, and the problem of fresh air from the roadway side flowing back into the goaf through the drainage pipe when drainage stops or due to negative pressure in the goaf, which can induce spontaneous combustion of residual coal.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an automatic drainage system for preventing spontaneous combustion and blockage in goaf areas, comprising: an isolation wall assembly installed between the bottom plate and the top plate and located at the stop line, wherein a drainage pipe assembly is installed inside the isolation wall assembly;

[0007] The isolation wall assembly includes an inner filter wall, a middle sealing wall, and an outer sealing wall in sequence from the goaf to the roadway side. The inner filter wall is provided with at least one baffle, and the multiple baffles are connected by adjusting rods and rotatably connected inside the inner filter wall. The adjusting rod is arranged vertically, with its lower end extending to the bottom of the inner filter wall and its upper end extending through the isolation wall assembly to the side of the alley and connected to a drive mechanism. The drive mechanism can drive the adjusting rod to make vertical reciprocating motion, thereby driving multiple baffles to rotate synchronously to clear the blockages on the outside of the baffles. A primary water filtration chamber is formed between the inner filter wall and the middle sealed wall. The cross-sectional area of ​​the primary water filtration chamber is larger than the total cross-sectional area of ​​the gap between the baffles on the inner filter wall, which is used to reduce the water flow velocity and settle sediment. The drainage pipeline assembly includes a drainage pipe with its inlet located in the primary filter chamber and its outlet extending to the roadway side. The surface of the drainage pipe is provided with two one-way valves and at least one bend. The one-way valves and the bend cooperate to form a dual anti-backflow structure of mechanical barrier and hydraulic seal, which is used to block air from entering the goaf.

[0008] This technical solution constructs a multi-level protection system. On the inner side, baffles are used for physical isolation and active unblocking. In the middle, a primary water filter chamber is used for flow rate buffering and sediment settling. On the outer side, a dual mechanism of one-way valve and bend pipe water seal is used to isolate air, thereby achieving safe drainage throughout the entire process from preventing blockage at the source to preventing backflow at the end.

[0009] Preferably, the baffle is rotatably connected to the frame of the inner filter wall by a pin, the adjusting rod passes through the baffle in a vertical direction, and the connection point between the adjusting rod and the baffle is offset from the rotation axis of the baffle.

[0010] This setup utilizes the principle of lever arm eccentricity to ensure that when the adjusting rod is pulled linearly, the force does not pass through the dead point of the baffle's rotation. This converts the vertical reciprocating motion of the adjusting rod into the rotational motion of the baffle around the pin, providing a mechanical basis for subsequent vibration-based unblocking.

[0011] Preferably, a limiting rod is fixedly connected to the surface of the adjusting rod, the limiting rod abuts against the bottom surface of the baffle, the center of gravity of the baffle is located on the side of the rotation axis closer to the goaf, and in its natural state tilts towards the goaf.

[0012] This structure enables the clearing of blockages through upward pushing and downward resetting: when the adjusting rod is raised, the limiting rod actively pushes the bottom of the baffle, causing the baffle to flip upward and open, breaking the gangue accumulation arch; when the adjusting rod is lowered, the limiting rod removes its support, and the baffle naturally falls back to its original position under gravity. This intermittent pushing vibration is more effective at shaking off debris stuck in the gaps than simple rotation.

[0013] Preferably, a central sealed chamber is formed between the central sealed wall and the outer sealed wall. The interior of the central sealed chamber is filled with a sealing and pressure-bearing material. The drain pipe passes through the central sealed wall, the central sealed chamber, and the outer sealed wall in a sealed manner, ensuring that the primary water filtration chamber is connected to the roadway side through the drain pipe.

[0014] The filling of sealing and pressure-bearing material further enhances the overall strength and airtightness of the isolation wall, eliminates gaps that may exist when pipelines pass through the wall, prevents harmful gases or water in the goaf from leaking into the roadway through the wall gaps, and also prevents outside air from entering the goaf through the wall cracks.

[0015] Preferably, the cross-sectional area of ​​the primary filter chamber is greater than the total cross-sectional area of ​​the gap between the baffles on the inner filter wall, the bottom of the primary filter chamber uses the bottom plate as a sedimentation surface, and the inlet height of the drain pipe is higher than the horizontal plane of the bottom plate.

[0016] Utilizing the principles of fluid dynamics, when water flows from the narrow gap between the baffles into the wide filter chamber, the flow velocity drops sharply, causing the fine suspended particles it carries to naturally settle to the bottom plate due to the loss of fluid dynamics. The raised inlet design ensures that the drain pipe only draws in the clear water from the upper layer, avoiding the inhalation of sediment from the bottom into the pipe and causing subsequent blockages.

[0017] Preferably, the two one-way valves are respectively installed on the roadway side of the drainage pipe. One of the one-way valves is installed on the section of the drainage pipe located outside the outer sealed wall, and the other one-way valve is installed at the outlet of the drainage pipe. The one-way valve is configured to allow water flow only from the goaf to the outlet direction and to automatically close when there is no water pressure.

[0018] The dual check valve design provides mechanical backflow protection. When drainage stops or suction occurs in the goaf, the valve disc automatically closes under back pressure, forming a rigid physical barrier to prevent air from flowing back due to pressure difference.

[0019] Preferably, the bend is located in the downstream section of the one-way valve, the bend is constructed as a continuous S-shaped or U-shaped structure, and a permanent water column is formed at the bottom of the bend.

[0020] Utilizing the principle of communicating vessels, regardless of whether there is a continuous water flow in the pipeline, a water column will always remain at the bottom of the bend. This water column forms a reliable hydraulic barrier. Even if the one-way valve leaks slightly, the water seal can effectively balance the negative pressure in the goaf and block the airflow.

[0021] Preferably, the drain pipe assembly further includes a backwash filter disposed at the bottom of the bend, the backwash filter being connected to the lowest point of the bend.

[0022] Given the geometric characteristics of bends in the pipe, the lowest point is where sediment is most likely to accumulate. Installing a backwash filter at this point can naturally capture and collect the high-density particles brought into the pipe by the water flow, preventing them from accumulating in the straight sections of the pipe.

[0023] Preferably, the backwash filter is provided with a drain control valve at the bottom.

[0024] This design gives the pipeline a self-cleaning function. When the drain control valve is opened, the existing water head pressure upstream of the drain pipeline can forcefully push the high concentration of sludge in the collection chamber out of the pipe, allowing maintenance to be completed without disassembling the pipeline.

[0025] Preferably, the system further includes an automated monitoring and control component, which includes a sensor for monitoring the water level in the primary filtration chamber, a flow meter for monitoring the drainage flow, and a control unit. The control unit is electrically connected to the sensor, the flow meter, and the system actuator to form a closed-loop control; The drive mechanism includes a winch with a motor and a traction rope. One end of the traction rope is wound around the winch, and the other end is connected to the upper end of the adjusting rod. The control unit is used to determine the blockage status of the inner filter wall based on water level and flow data, and transmits the signal to the motor of the winch. The motor drives the winch to raise and lower the traction rope, thereby driving the adjusting rod to perform vertical reciprocating motion to clear the stone blockage on the outside of the baffle. The sewage control valve is a solenoid valve, and an electric shut-off valve controlled by the control unit is also installed at the outlet of the drain pipe. The control unit can control the drain control valve to automatically drain sewage at set times, or, before clearing blockages in the bend, the control unit can briefly close the electric shut-off valve, using the continuously accumulated water pressure in the pipe to form a high-pressure jet when the drain control valve is opened instantaneously, which helps to flush out the blockages in the backwash filter and bend.

[0026] Through the fusion analysis of sensor data, the system can intelligently identify blockage conditions (such as high water level and low flow rate) and automatically trigger the clearing action driven by the regulating rod, realizing continuous and stable operation in an unattended state. At the same time, in conjunction with the linkage of the electric shut-off valve and the sewage discharge solenoid valve, it not only realizes the automatic timed sewage discharge of the system, but also solves the pain point of difficult cleaning of mud and sand accumulation in low-lying dead corners of the pipeline, realizing dual fully automatic clearing of blockages through the combination of mechanical vibration and fluid power.

[0027] This invention provides an automatic drainage system for preventing spontaneous combustion and blockage in goaf areas caused by drafty air. It offers the following advantages: 1. This invention, by setting an eccentrically connected adjusting rod and limiting rod on the baffle, utilizes the active abutment and pushing mechanism of the limiting rod and the gravity reset mechanism after force release to convert the vertical linear motion of the adjusting rod into the reciprocating vibration and flipping motion of the baffle around the pin shaft. This mechanical action can disrupt the arched structure of coal slime and gangue accumulated on the outer side of the inner filter wall, forcing the blockage to loosen and fall off, thereby solving the problem of drainage interruption caused by gangue blockage of traditional static filter screens, and ensuring the continuous discharge of water accumulated in the goaf.

[0028] 2. This invention employs a dual anti-backflow structure combining mechanical check valves and hydraulic bend water seals in the drainage pipeline assembly. Two check valves are located at opposite ends of the pipeline, automatically closing to create physical isolation under static or back pressure conditions. Combined with a permanent water column formed at the bottom of the bend using the principle of communicating vessels, the gravitational potential energy of this water column balances the negative pressure suction within the goaf. This method blocks the path of fresh air flowing backwards into the goaf through the drainage pipe, eliminating the risk of spontaneous combustion of residual coal due to air leakage.

[0029] 3. This invention utilizes the principle of rapid flow velocity reduction in the large cross-section of the primary filter chamber and the principle of gravity settling at the bottom of the bend to construct a graded sediment treatment system. The primary filter chamber reduces the flow velocity, causing a large amount of sediment carried in the water to settle to the bottom plate before entering the pipeline; the backwash filter located at the lowest point of the bend further captures fine particles entering the pipeline and uses the water pressure inside the pipe to discharge the sludge by opening the sewage control valve. This design reduces the risk of high-concentration sediment water entering long-distance pipelines and causing sludge accumulation and blockage, and enables online cleaning and maintenance of the pipeline interior without disassembly. Attached Figure Description

[0030] Figure 1 This is a first-view perspective perspective view of the present invention; Figure 2 This is a second-view perspective perspective view of the present invention; Figure 3 This is a schematic diagram of the isolation wall assembly of the present invention; Figure 4 This is a schematic diagram of the isolation wall component of the present invention; Figure 5 For the present invention Figure 4 Enlarged view of point A in the middle.

[0031] The components are as follows: 1. Base plate; 2. Outer sealed wall; 3. Middle sealed wall; 4. Inner filter wall; 5. Top plate; 6. Middle sealed chamber; 7. Primary filter chamber; 8. Baffle; 9. Adjusting rod; 10. Limiting rod; 11. Drainage pipe; 12. Bend; 13. Backwash filter; 14. Check valve; 15. Goaf; 16. Stop line. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Please see Figures 1-5 The present invention provides an automatic drainage system for preventing spontaneous combustion and blockage in goaf areas, including an isolation wall assembly installed between the bottom plate 1 and the top plate 5 and located at the stop line 16, and a drainage pipe assembly passing through the inside of the isolation wall assembly; The isolation wall assembly includes, from the inside to the outside, an inner filter wall 4, a middle sealing wall 3 and an outer sealing wall 2 from the inside to the outside of the goaf 15 towards the roadway. The inner filter wall 4 is provided with at least one baffle 8. Multiple baffles 8 are connected by adjusting rods 9 and are rotatably connected inside the inner filter wall 4. The adjusting rod 9 is arranged vertically, with its lower end extending to the bottom of the inner filter wall 4 and its upper end extending through the isolation wall assembly to the side of the alley and connected to a drive mechanism. The drive mechanism can drive the adjusting rod 9 to make vertical reciprocating motion, thereby driving multiple baffles 8 to rotate synchronously to clean the blockages on the outside of the baffles 8. A primary water filter chamber 7 is formed between the inner filter wall 4 and the middle sealed wall 3. The cross-sectional area of ​​the primary water filter chamber 7 is larger than the total cross-sectional area of ​​the gap between the baffles 8 on the inner filter wall 4, which is used to reduce the water flow velocity and settle sediment. The drainage pipeline assembly includes a drainage pipe 11. The water inlet of the drainage pipe 11 is located in the primary water filter chamber 7, and the water outlet extends to the side of the roadway. The surface of the drainage pipe 11 is provided with two one-way valves 14 and at least one bend 12. The one-way valves 14 and the bend 12 cooperate to form a dual anti-backflow structure of mechanical barrier and hydraulic water seal, which is used to block air from entering the goaf 15.

[0034] Specifically, the isolation wall assembly installed at the stop line 16 not only serves to physically seal off the goaf 15, but also acts as the installation base for the automatic drainage system that prevents spontaneous combustion and blockage of the entire goaf. By layering the inner filter wall 4, the middle sealing wall 3, and the outer sealing wall 2, the automatic drainage system that prevents spontaneous combustion and blockage of the goaf can achieve coarse filtration, sedimentation and clarification, and sealed discharge of the water accumulated in the goaf 15. The inner filter wall 4 serves as the first line of defense, using baffles 8 to intercept large pieces of gangue; the primary water filter chamber 7 serves as a buffer zone, using its large cross-sectional area to reduce the flow velocity, allowing fine silt to naturally settle on the bottom plate 1, thus protecting the subsequent drainage pipe 11 from blockage; while the one-way valve 14 and bend 12 located on the drainage pipe 11 constitute the end protection system, ensuring that when drainage stops or negative pressure suction occurs inside the goaf 15, fresh air from the external roadway cannot break through the seal of the drainage pipe 11 to enter the goaf 15, thereby eliminating the safety hazard of spontaneous combustion of residual coal.

[0035] Please see Figures 3-5 The baffle 8 is rotatably connected to the frame of the inner filter wall 4 by a pin. The adjusting rod 9 passes through the baffle 8 in the vertical direction. The connection point between the adjusting rod 9 and the baffle 8 is offset from the rotation axis of the baffle 8.

[0036] Specifically, the adjusting rod 9 and the baffle 8 are in a clearance fit, allowing the adjusting rod 9 to slide freely axially through the pre-drilled holes or gaps in the baffle 8. Furthermore, there is a preset horizontal eccentricity between the axial path of the adjusting rod 9 and the center line of the pin shaft of the baffle 8. This eccentric through-type connection is used to establish the mechanical basis for converting the linear reciprocating motion of the adjusting rod 9 into the rotational motion of the baffle 8. Because the path of the adjusting rod 9 deviates from the rotation center of the baffle 8, when components on the adjusting rod 9 act on the baffle 8, the force will not pass through the dead point of rotation of the baffle 8, thus generating an effective rotational torque. Simultaneously, the sliding fit between the adjusting rod 9 and the baffle 8 allows the adjusting rod 9 to move independently of the baffle 8, providing flexibility for subsequent impact or push-type drives and avoiding structural jamming or motion stiffness caused by rigid connections.

[0037] Please see Figures 3-5 A limiting rod 10 is fixedly connected to the surface of the adjusting rod 9. The limiting rod 10 abuts against the bottom surface of the baffle 8. The center of gravity of the baffle 8 is located on the side of the rotation axis closer to the goaf 15, and it tilts towards the goaf 15 in a natural state.

[0038] Specifically, the outer diameter of the limiting rod 10 is larger than the aperture through which the adjusting rod 9 passes through the baffle 8, preventing the limiting rod 10 from passing through the baffle 8 and thus forming a unidirectional displacement restriction and transmission node. The center of gravity design of the baffle 8 ensures that the baffle 8 always maintains a downward tendency towards the goaf 15 when not pulled by external force, using the weight of the baffle 8 itself as the reset force. The vibration clearing function is achieved through the cyclic action of active jacking opening and gravity automatic reset. When coal slurry or gangue on the side of the goaf 15 causes blockage, the control system drives the adjusting rod 9 to rise, and the limiting rod 10 fixed on the adjusting rod 9 rises accordingly and forcefully pushes the bottom of the baffle 8, forcing the baffle 8 to overcome gravity and rotate upward around the pin axis to open, disrupting the force balance of the external accumulation. Subsequently, the adjusting rod 9 is driven to quickly fall down, the limiting rod 10 removes its support for the baffle 8, and the baffle 8 quickly falls back to reset under the action of gravity, producing a striking and shearing effect on the remaining blockage. This intermittent mechanical vibration driven by the limit rod 10, compared to simple static opening, can shake off debris adhering to the surface of the baffle 8, ensuring continuous filtration.

[0039] Please see Figures 1-2 The central sealed wall 3 and the outer sealed wall 2 form a central sealed chamber 6. The central sealed chamber 6 is filled with sealing and pressure-bearing material. The drain pipe 11 passes through the central sealed wall 3, the central sealed chamber 6 and the outer sealed wall 2 in a sealed manner, ensuring that the primary water filtration chamber 7 is connected to the roadway side through the drain pipe 11.

[0040] Specifically, the central sealed chamber 6 and the sealing pressure-bearing material filled inside the central sealed chamber 6 enhance the overall airtightness and compressive strength of the isolation wall assembly. In the complex stress environment of underground coal mines, single-layer walls are prone to micro-cracks due to changes in ground pressure. By filling the space between the central sealed wall 3 and the outer sealed wall 2 with sealing pressure-bearing material, a composite barrier layer is formed. This composite barrier layer eliminates the leakage channels that may exist between the outer wall of the drainage pipe 11 and the wall. The filling of the sealing pressure-bearing material ensures that the drainage pipe 11 becomes the only channel connecting the interior of the primary water filter chamber 7 with the external environment of the roadway, preventing toxic and harmful gases in the goaf 15 from leaking to the roadway side through the wall gaps. At the same time, it also prevents fresh air from the roadway side from seeping into the goaf 15 through the wall cracks. In addition, in order to ensure that the overall airtightness is not compromised when the adjusting rod 9 or the traction rope passes through the isolation wall assembly, a guide sleeve with a dynamic sealing structure (such as sealing grease or sealing ring) is pre-embedded inside the isolation wall assembly. The upper end of the adjusting rod 9 or the traction rope extends through the guide sleeve to the roadway side and connects with the winch, thereby ensuring smooth mechanical transmission while eliminating air leakage channels.

[0041] Please see Figures 1-2The cross-sectional area of ​​the primary filter chamber 7 is greater than the total cross-sectional area of ​​the gap between the baffles 8 on the inner filter wall 4. The bottom of the primary filter chamber 7 uses the bottom plate 1 as the sedimentation surface, and the inlet height of the drain pipe 11 is higher than the horizontal plane of the bottom plate 1.

[0042] Specifically, the above structure utilizes the principle in fluid mechanics that flow velocity is inversely proportional to the cross-sectional area of ​​the flow path to achieve the physical sedimentation of suspended impurities. When water carrying impurities flows at high speed from the narrow gap of the baffle 8 into the relatively spacious primary filtration chamber 7, the instantaneous widening of the water flow path causes a sharp drop in the kinetic energy and flow velocity of the fluid, reducing the water flow's ability to carry solid particles. The denser silt and coal slurry will naturally settle and accumulate on the bottom plate 1 under gravity. Furthermore, the inlet of the drain pipe 11 is positioned above the bottom plate 1, and a dedicated sediment storage space is reserved at the bottom of the primary filtration chamber 7. This height difference ensures that the drain pipe 11 only draws naturally clarified liquid from the upper layer of the primary filtration chamber 7, preventing silt deposited on the bottom plate 1 from being re-inhaled into the drain pipe 11, thereby reducing the risk of blockage in subsequent pipelines.

[0043] Please see Figures 1-2 Two one-way valves 14 are respectively installed on the roadway side of the drainage pipe 11. One one-way valve 14 is installed on the section of the drainage pipe 11 located outside the outer sealing wall 2, and the other one-way valve 14 is installed at the outlet of the drainage pipe 11. The one-way valve 14 is constructed to allow water flow to pass unidirectionally from the goaf 15 to the outlet, and automatically closes when there is no water flow pressure.

[0044] Specifically, this arrangement of double-ended distributed check valves 14 provides mechanical backflow protection for the drainage pipeline assembly. Under normal drainage conditions, the water pressure from the goaf 15 overcomes the valve disc resistance of the check valve 14, keeping it open to allow water flow. When drainage stops or negative pressure suction is generated inside the goaf 15 due to temperature drop and gas contraction, the pressure difference on both sides of the check valve 14 reverses, and the valve disc of the check valve 14 quickly closes against the valve seat under back pressure, forming a rigid physical barrier. The check valves 14 located on the pipe section and the check valves 14 located at the outlet work together. Even if one check valve 14 cannot close completely due to foreign object obstruction, the other check valve 14 can still maintain a sealed state independently, thereby improving the reliability of preventing external air from flowing back into the goaf 15 through the drainage pipe 11.

[0045] Please see Figures 1-2 The bend 12 is located in the downstream section of the one-way valve 14. The bend 12 is constructed as a continuous S-shaped or U-shaped structure, and a permanent water column is formed at the bottom of the bend 12.

[0046] Specifically, the bend 12 utilizes the principle of communicating vessels to construct a second hydraulic barrier independent of the mechanical valve. Regardless of whether there is a continuous flow of water in the drain pipe 11, the unique S-shaped or U-shaped concave structure of the bend 12 ensures that a section of permanent water column filling the pipe diameter is always retained at the bottom of the bend 12. This permanent water column completely isolates the air upstream of the bend 12 from the air downstream of the bend 12. When a negative pressure is generated inside the goaf 15 and attempts to draw in external air through the drain pipe 11, the permanent water column uses its own gravitational potential energy to counteract the pressure difference between the external atmospheric pressure and the negative pressure inside the goaf 15. As long as the negative pressure value does not exceed the hydrostatic pressure corresponding to the height of the permanent water column, external air cannot break through the blockage of the permanent water column. The hydraulic seal formed by the bend 12 and the mechanical seal formed by the one-way valve 14 work together to prevent the path of air backflow.

[0047] Please see Figures 1-2 The drainage pipe assembly also includes a backwash filter 13 disposed at the bottom of the bend 12, the backwash filter 13 being connected to the lowest point of the bend 12.

[0048] Specifically, the specific layout of the backwash filter 13 at the lowest point of the bend 12 utilizes the geometric characteristics of the pipeline and the principle of gravity settling to capture fine particles. When water containing trace amounts of fine sediment flows through the S-shaped or U-shaped bend 12, the density of the sediment is greater than that of water. Under the combined action of gravity and the centrifugal force generated by the change in water flow, the sediment will naturally settle towards the bottom of the bend 12 where the potential energy is lowest. The backwash filter 13 acts as a collection trap, gathering and temporarily storing these settled high-density fine particles within its cavity, preventing the fine particles from gradually accumulating in the downstream riser section of the bend 12 and thus reducing the flow area.

[0049] Please see Figures 1-2 The backwash filter 13 is equipped with a drain control valve at the bottom.

[0050] Specifically, the drain control valve enables the drainage piping assembly to perform online self-cleaning without disassembling the piping. During routine operation or maintenance of the drainage piping assembly, opening the drain control valve creates a high-pressure flushing flow at the drain outlet of the backwash filter 13, where the water column pressure inside the drain pipe 11 and bend 12 forces the high-concentration sludge accumulated in the backwash filter 13 out of the piping system. This design utilizes the fluid's own potential energy to complete the cleaning process, solving the problem of cleaning sludge buildup in low-lying sections of long-distance piping.

[0051] Please see Figures 1-2 The system also includes an automated monitoring and control component, which includes a sensor for monitoring the water level in the primary filtration chamber 7, a flow meter for monitoring the drainage flow, and a control unit. The control unit is electrically connected to the sensors, flow meters, and system actuators to form a closed-loop control. The drive mechanism includes a winch with a motor and a traction rope. One end of the traction rope is wound around the winch, and the other end is connected to the upper end of the adjusting rod 9. The control unit is used to determine the blockage status of the inner filter wall 4 based on water level and flow data, and transmits the signal to the motor of the winch. The motor drives the winch to raise and lower the traction rope, thereby driving the adjusting rod 9 to perform vertical reciprocating motion to clear the stone blockage on the outside of the baffle 8. The sewage control valve is a solenoid valve, and an electric shut-off valve controlled by the control unit is also installed at the outlet of the drain pipe 11. The control unit can control the drain control valve to automatically drain sewage at set times, or before clearing the blockage in the bend 12, the control unit can briefly close the electric shut-off valve and use the water pressure that is continuously accumulated in the pipe to form a high-pressure jet when the drain control valve is opened at an instant, which helps to flush out the blockage in the backwash filter 13 and the bend 12.

[0052] Specifically, the automated monitoring and control component achieves intelligent closed-loop control of the system by integrating data from sensors and flow meters. When the sensor detects that the water level in the primary filter chamber 7 has reached the preset drainage threshold, the automated monitoring and control component starts the drainage equipment to perform drainage operations. During the drainage process, if the sensor detects a high water level signal and the flow meter simultaneously detects that the drainage flow rate is lower than the normal value, the automated monitoring and control component determines that the gap of the baffle 8 is blocked. Subsequently, the automated monitoring and control component sends a command to the winch connected to the traction rope to control the motor on the winch to rotate in both directions. By raising and lowering the traction rope through the winch, the adjusting rod 9 is driven to perform vertical reciprocating motion, which in turn drives the baffle 8 to vibrate and clear the blockage, ensuring the continuity and stability of the drainage operation in an unattended environment.

[0053] Working principle: When the monitoring component detects that the water level in the goaf 15 rises and overflows the stop line 16 and contacts the inner filter wall 4, the accumulated water attempts to pass through the gaps in the baffle 8 under hydrostatic pressure. Large pieces of gangue are physically intercepted by the naturally tilted baffle 8. If the sensor detects an abnormal rise in water level or a decrease in flow indicating blockage, the system control unit sends a closed-loop control signal to the winch motor. The motor starts and drives the winch to wind up and down the traction rope, thereby controlling the adjusting rod 9 to perform vertical reciprocating motion. When the winch winds up the rope and drives the adjusting rod 9 upward, the limiting rod 10 fixed on it rises synchronously and actively abuts and pushes the bottom surface of the baffle 8, forcing the baffle 8 to overcome gravity and rotate upward around the pin axis to open, destroying the externally accumulated gangue arch. When the winch reverses and loosens the rope, the limiting rod 10 removes the support force when the adjusting rod 9 descends. The baffle 8 falls back to its original position under gravity and knocks down the residue, restoring the flow through this mechanical vibration. After filtration, the water flows into the primary filtration chamber 7. Due to the widening of the flow channel, the flow velocity drops sharply, and the sediment settles to the bottom plate 1. The upper layer of clarified water submerges the inlet of the drain pipe 11 and flows outward through the sealed middle sealed wall 3, the middle sealed chamber 6 filled with pressure-bearing material, and the outer sealed wall 2.

[0054] Driven by potential energy, the water flow in the pipeline sequentially opens the first one-way valve 14 located on the outer pipe section of the outer sealed wall 2, and then discharges after passing through the normally open electric shut-off valve. During this process, when a small amount of fine particles move to the low-lying area of ​​the bend 12, they naturally settle into the backwash filter 13 chamber. The system control unit can control the bottom drain control valve to automatically drain the wastewater at set times. When it is determined that the bend 12 is severely blocked, the control unit briefly closes the electric shut-off valve to cut off the drainage, and uses the continuous water inflow from the goaf 15 to accumulate a very high static water pressure in the pipe, and then instantly opens the valve. The bottom sewage control valve uses the instantaneous pressure difference to form a high-pressure rapid discharge jet. The high pressure accumulated in the pipe can help to flush out and expel silt and blockages. When drainage stops or the goaf 15 generates negative pressure suction due to gas contraction, the two one-way valves 14 at both ends of the pipeline close mechanically at the same time under the back pressure, forming a double rigid barrier. At the same time, the bend 12 uses the principle of communicating vessels to always retain a section of water column that fills the pipe diameter, forming a hydraulic barrier. The gravitational potential energy of the water column balances the pressure difference, and together with the one-way valve 14, completely blocks the backflow of air from the roadway into the goaf 15.

Claims

1. An automatic drainage system for preventing spontaneous combustion and blockage in goaf areas, characterized in that, include: An isolation wall assembly is installed between the bottom plate (1) and the top plate (5) and located at the stop mining line (16), and a drainage pipe assembly is installed inside the isolation wall assembly; The isolation wall assembly includes an inner filter wall (4), a middle sealing wall (3) and an outer sealing wall (2) in sequence from the goaf (15) to the roadway side (from inside to outside). The inner filter wall (4) is provided with at least one baffle (8), and multiple baffles (8) are connected by adjusting rods (9) and rotatably connected inside the inner filter wall (4). The adjusting rod (9) is arranged vertically, with its lower end extending to the bottom of the inner filter wall (4) and its upper end extending through the isolation wall assembly to the side of the alley and connected to a driving mechanism. The driving mechanism can drive the adjusting rod (9) to make vertical reciprocating motion, thereby driving multiple baffles (8) to rotate synchronously to clean the blockages on the outside of the baffles (8). A primary water filter chamber (7) is formed between the inner filter wall (4) and the middle sealed wall (3). The cross-sectional area of ​​the primary water filter chamber (7) is larger than the total cross-sectional area of ​​the gap between the baffles (8) on the inner filter wall (4), which is used to reduce the water flow velocity and settle sediment. The drainage pipeline assembly includes a drainage pipe (11), the inlet of which is located in the primary filter chamber (7), and the outlet extends to the side of the roadway. The surface of the drainage pipe (11) is provided with two one-way valves (14) and at least one bend (12). The one-way valves (14) and the bend (12) cooperate to form a dual anti-backflow structure of mechanical barrier and hydraulic water seal, which is used to block air from entering the goaf (15).

2. The automatic drainage system for preventing spontaneous combustion and blockage in goaf areas according to claim 1, characterized in that, The baffle (8) is rotatably connected to the frame of the inner filter wall (4) by a pin. The adjusting rod (9) passes through the baffle (8) in the vertical direction. The connection point between the adjusting rod (9) and the baffle (8) is offset from the rotation axis of the baffle (8).

3. The automatic drainage system for preventing spontaneous combustion and blockage in goaf areas according to claim 2, characterized in that, The adjusting rod (9) is fixedly connected to a limiting rod (10), which abuts against the bottom surface of the baffle (8). The center of gravity of the baffle (8) is located on the side of the rotation axis close to the goaf (15), and it tilts towards the goaf (15) in its natural state.

4. The automatic drainage system for preventing spontaneous combustion and blockage in goaf areas according to claim 1, characterized in that, The central sealed wall (3) and the outer sealed wall (2) form a central sealed chamber (6). The central sealed chamber (6) is filled with sealing and pressure-bearing material. The drain pipe (11) passes through the central sealed wall (3), the central sealed chamber (6) and the outer sealed wall (2) in a sealed manner, ensuring that the primary water filtration chamber (7) is connected to the roadway side through the drain pipe (11).

5. The automatic drainage system for preventing spontaneous combustion and blockage in goaf areas according to claim 1, characterized in that, The bottom of the primary filter chamber (7) uses the base plate (1) as the sedimentation surface, and the inlet of the drain pipe (11) is higher than the horizontal plane of the base plate (1).

6. The automatic drainage system for preventing spontaneous combustion and blockage in goaf areas according to claim 1, characterized in that, Two check valves (14) are respectively installed on the roadway side of the drainage pipe (11). One of the check valves (14) is installed on the pipe section of the drainage pipe (11) located outside the outer sealing wall (2), and the other check valve (14) is installed at the outlet of the drainage pipe (11). The check valve (14) is configured to allow water flow only from the goaf (15) to the outlet direction, and automatically closes when there is no water flow pressure.

7. The automatic drainage system for preventing spontaneous combustion and blockage in goaf areas according to claim 1, characterized in that, The bend (12) is located in the downstream section of the one-way valve (14). The bend (12) is constructed as a continuous S-shaped or U-shaped structure, and a permanent water column is formed at the bottom of the bend (12).

8. The automatic drainage system for preventing spontaneous combustion and blockage in goaf areas according to claim 7, characterized in that, The drainage pipe assembly also includes a backwash filter (13) disposed at the bottom of the bend (12), the backwash filter (13) being connected to the lowest point of the bend (12).

9. The automatic drainage system for preventing spontaneous combustion and blockage in goaf areas according to claim 8, characterized in that, The backwash filter (13) is equipped with a drain control valve at the bottom.

10. The automatic drainage system for preventing spontaneous combustion and blockage in goaf areas according to claim 9, characterized in that, The system also includes an automated monitoring and control component, which includes a sensor for monitoring the water level of the primary water filtration chamber (7), a flow meter for monitoring the drainage flow, and a control unit; The control unit is electrically connected to the sensor, the flow meter, and the system actuator to form a closed-loop control; The drive mechanism includes a winch with a motor and a traction rope. One end of the traction rope is wound around the winch, and the other end is connected to the upper end of the adjusting rod (9). The control unit is used to determine the blockage status of the inner filter wall (4) based on the water level and flow data, and transmits the signal to the motor of the winch. The motor drives the winch to raise and lower the traction rope, thereby driving the adjusting rod (9) to perform vertical reciprocating motion to clear the stone blockage on the outside of the baffle (8). The sewage control valve is a solenoid valve, and an electric shut-off valve controlled by the control unit is also provided at the outlet of the drain pipe (11). The control unit can control the drain control valve to automatically drain sewage at set times, or before clearing the blockage in the bend (12), the control unit can briefly close the electric shut-off valve and use the water pressure that is continuously accumulated in the pipe to form a high-pressure jet when the drain control valve is opened at an instant, which helps to flush out the blockage in the backwash filter (13) and the bend (12).

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