A self-repairing method for coal rock cracks

Abstract

The present invention relates to a method for effectively solving the problem of coal rock cracks, and a technical solution thereof is to use inorganic grouting reinforcement materials for mining as a plugging liquid for repair. In the absence of human interference, when cracks occur in the coal rock, nitrogen flows out through the cracks, causing the air pressure valve to change. The changed data is transmitted to the control device and displayed on the display screen at the same time. Relevant personnel can analyze the process of data change. After analysis, the controller triggers the gas-liquid separation switch to work, opens the plugging liquid and closes the nitrogen. The plugging liquid is sprayed onto the coal rock cracks through the gas-liquid coexistence grouting pipeline. After the cracks are filled, the controller triggers the gas-liquid separation switch again. This high-efficiency circulating crack filling method can repair the harmful cracks generated in the coal rock to the greatest extent and for the longest time, and is an innovation in the self-repair method of coal rock cracks.

Description

Technical Field

[0001] The present invention relates to the field of coal mine safety, and in particular to a method for self-repairing cracks in coal and rock masses. Background Art

[0002] Safety is paramount in coal mining operations. The formation of cracks in coal and rock masses significantly exacerbates safety hazards. In mine ventilation systems, airflow leaks through small cracks. This leakage reduces the effective air volume at the working face, leading to the accumulation of gas and coal dust and elevated temperatures. This not only reduces production efficiency but also affects the health of underground workers. In areas with large amounts of floating coal, such as goafs, closed tunnels, and crushed and damaged coal pillars, crack leakage can easily lead to spontaneous combustion of the coal. Furthermore, when underground coal fires occur, surface cracks can carry large amounts of toxic and harmful gases to the surface, causing environmental pollution. In cracks in tunnels, the toxic and harmful gases generated by combustion can leak through the cracks into safe areas underground, potentially endangering these areas and severely jeopardizing the lives of underground personnel, threatening safe production. Therefore, it is crucial to design a self-repairing device for coal and rock cracks and provide an effective method to prevent the formation of cracks in coal and rock masses. Summary of the Invention

[0003] In view of the above situation, in order to solve the defects of the existing technology, the purpose of the present invention is to provide a self-repairing method for coal rock cracks, which can effectively solve the problem of coal rock cracks.

[0004] The technical solution provided by the present invention is that the repair method utilizes a coal rock mass crack self-repairing device and is carried out in the following steps:

[0005] 1) Install the coal-rock fracture self-repairing device on the rock wall where fractures may occur. Select a gas-liquid coexistence grouting pipeline 24 of appropriate length according to the depth of the rock wall. Install a certain number of plugging liquid injection pipelines 19 inside the pipeline, and connect it to the control device through the gas-liquid separation switch pipeline and the gas-liquid separation switch.

[0006] 2) When nitrogen leaks from a crack in the coal rock wall of the installed coal rock crack self-repairing device, the pressure signal of the air pressure valve 8 is converted into an electrical signal and transmitted to the display screen 3. When the display screen 3 receives the change signal transmitted by the air pressure valve 8, it analyzes the signal and transmits it to the gas-liquid separation switch. The forward and reverse servo 10 in the gas-liquid separation switch rotates 180 degrees after receiving the crack signal from the controller, shutting off the nitrogen by closing the external semicircular baffle 13 and the nitrogen baffle 15;

[0007] 3) The plugging liquid is opened to plug the cracks. The plugging liquid enters the gas-liquid coexistence grouting pipeline 24 through the gas-liquid separation switch 22 and the gas-liquid separation switch pipeline 23 in sequence, and then seeps into the coal rock fissures through the plugging liquid injection pipe 19 provided in the gas-liquid coexistence grouting pipeline 24.

[0008] 4) After the plugging begins, the controller controls the steering gear 10 to rotate 180° every half hour. During this process, the central semicircular baffle 12 and the slurry baffle 16 are closed to shut off the plugging fluid 1 and the nitrogen 7 is opened. The nitrogen passes through the second outer large tube 17-2 and the second inner small tube 18-2 and is distributed throughout the coal rock through the surface micropores 20;

[0009] 5) If the air pressure valve 8 does not change, it means that the crack has been filled and blocked, and the nitrogen 7 remains connected for crack detection. If the air pressure valve 8 changes, it means that the crack still exists. The controller controls the steering gear 10 to rotate 180 degrees again. This process is repeated until the air pressure valve 8 does not change. When the crack is completely filled and blocked, the nitrogen 7 continues to penetrate the coal rock mass for crack detection.

[0010] The present invention utilizes XZZJ-J inorganic grouting reinforcement material for mining as a plugging liquid for repair. In the absence of human interference, when cracks occur in coal rock, nitrogen flows out through the cracks, causing the air pressure valve to change. The changed data is transmitted to the control device and displayed on the display screen at the same time. Relevant personnel can analyze the process of data change. After analysis, the controller triggers the gas-liquid separation switch to work, opens the plugging liquid and closes the nitrogen. The plugging liquid is sprayed to the coal rock cracks through the gas-liquid coexistence grouting pipeline to complete the crack repair process. The feedback system can detect whether the cracks are filled. After the cracks are filled, the controller triggers the gas-liquid separation switch again, opens the nitrogen, closes the plugging liquid, and continues to use nitrogen to detect whether cracks have occurred in the coal rock. This efficient cyclic crack filling method can repair the harmful cracks generated in the coal rock mass to the greatest extent and for the longest time, and is an innovation in the coal rock mass crack self-repair device and repair method. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0012] Figure 2 Schematic diagram of the control device structure of the present invention.

[0013] Figure 3 It is a schematic diagram of the structure of the gas-liquid separation switch of the present invention.

[0014] Figure 4 This is a schematic diagram of the gas-liquid separation switch pipeline structure of the present invention.

[0015] Figure 5 This is a schematic diagram of the gas-liquid coexistence grouting pipeline structure of the present invention. DETAILED DESCRIPTION

[0016] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0017] Depend on Figure 1-5 The repair method of the present invention utilizes a coal rock fracture self-repairing device and is carried out in the following steps:

[0018] 1) Install the coal-rock fracture self-repairing device on the rock wall where fractures may occur. Select a gas-liquid coexistence grouting pipeline 24 of appropriate length according to the depth of the rock wall. Install a certain number of plugging liquid injection pipelines 19 inside the pipeline, and connect it to the control device through the gas-liquid separation switch pipeline and the gas-liquid separation switch.

[0019] 2) When nitrogen leaks from a crack in the coal rock wall of the installed coal rock crack self-repairing device, the pressure signal of the air pressure valve 8 is converted into an electrical signal and transmitted to the display screen 3. When the display screen 3 receives the change signal transmitted by the air pressure valve 8, it analyzes the signal and transmits it to the gas-liquid separation switch. The forward and reverse servo 10 in the gas-liquid separation switch rotates 180 degrees after receiving the crack signal from the controller, shutting off the nitrogen by closing the external semicircular baffle 13 and the nitrogen baffle 15;

[0020] 3) The plugging liquid is opened to plug the cracks. The plugging liquid enters the gas-liquid coexistence grouting pipeline 24 through the gas-liquid separation switch 22 and the gas-liquid separation switch pipeline 23 in sequence, and then seeps into the coal rock fissures through the plugging liquid injection pipe 19 provided in the gas-liquid coexistence grouting pipeline 24.

[0021] 4) After the plugging begins, the controller controls the steering gear 10 to rotate 180° every half hour. During this process, the central semicircular baffle 12 and the slurry baffle 16 are closed to shut off the plugging fluid 1 and the nitrogen 7 is opened. The nitrogen passes through the second outer large tube 17-2 and the second inner small tube 18-2 and is distributed throughout the coal rock through the surface micropores 20;

[0022] 5) If the air pressure valve 8 does not change, it means that the crack has been filled and blocked, and the nitrogen 7 remains connected for crack detection. If the air pressure valve 8 changes, it means that the crack still exists. The controller controls the steering gear 10 to rotate 180 degrees again. This process is repeated until the air pressure valve 8 does not change. When the crack is completely filled and blocked, the nitrogen 7 continues to penetrate the coal rock mass for crack detection.

[0023] The coal rock fracture self-repairing device includes a control device and a gas-liquid device. The control device 21 includes a bracket, a filling liquid tank 1, a display screen 3, a nitrogen tank 7 and a controller 4. The bracket is equipped with a filling liquid tank 1 and a nitrogen tank 7. The filling liquid tank 1 is connected to the controller 4 via a first pipeline, and the nitrogen tank 7 is connected to the controller 4 via a second pipeline. The controller 4 is connected to the display screen 3. The gas-liquid device is composed of a gas-liquid separation switch 22, a gas-liquid separation switch pipeline 23 and a gas-liquid coexistence grouting pipeline 24. The gas-liquid separation switch 22 includes a forward and reverse servo 10, a transmission shaft 11, and a fixed frame 14. The forward and reverse servo 10 is installed on the fixed frame 14. A central semicircular baffle 12 is installed on the transmission shaft 11 of the forward and reverse servo 10. An outer semicircular baffle 13 is installed on the central semicircular baffle 12. The forward and reverse servo 10 is connected to the controller 4. The gas-liquid separation switch 22 is installed in the gas-liquid separation switch pipeline 23. Inside, the gas-liquid separation switch pipe 23 includes a nitrogen baffle 15, a slurry baffle 16, a first external large pipe 17-1, and a first internal small pipe 18-1. The first external large pipe 17-1 is equipped with the first internal small pipe 18-1. A nitrogen baffle 15 is arranged between the first external large pipe 17-1 and the first internal small pipe 18-1. A slurry baffle 16 is arranged on the first internal small pipe 18-1. The gas-liquid separation switch pipe 23 is connected to the gas-liquid coexistence grouting pipe 24. The gas-liquid coexistence grouting pipe 24 includes a second external large pipe 17-2, a second internal small pipe 18-2, a plugging liquid injection pipe 19, and surface micropores 20. The second external large pipe 17-2 is equipped with the second internal small pipe 18-2. The second external large pipe 17-2 is provided with surface micropores 20. A plurality of plugging liquid injection pipes 19 are arranged between the second external large pipe 17-2 and the second internal small pipe 18-2.

[0024] In order to ensure the use effect, the first pipeline is equipped with a first switch valve 2, and the second pipeline is equipped with a second switch valve 9.

[0025] The nitrogen tank 7 is provided with an air pressure valve 8 .

[0026] The plugging liquid tank 1 is filled with plugging liquid, which is XZZJ-J inorganic grouting reinforcement material for mining.

[0027] The fixing frame 14 is fixed on the first outer large tube 17-1, and the forward and reverse servo 10 and the transmission shaft 11 are installed in the first inner small tube 18-1.

[0028] The second outer large tube 17 - 2 and the second inner small tube 18 - 2 are connected and fixed together through a plugging liquid injection pipe 19 ; there are a large number of micropores 20 on the surface of the outer large tube 17 , and if there is no coal rock blocking the surface, a large amount of nitrogen can be released through the micropores 20 .

[0029] The controller 4 and the display screen 3 are connected to an external power supply 5 .

[0030] The controller 4 is a PLC programmable logic controller.

[0031] The transmission shaft 11 extends into the first internal small tube 18 - 1 and is fixed thereto.

[0032] The diameters of the first outer large tube 17 - 1 and the second outer large tube 17 - 2 match each other, and the diameters of the first inner small tube 18 - 1 and the second inner small tube 18 - 2 match each other.

[0033] The control device 21 is mounted on the mounting frame 6 .

[0034] The usage of the present invention is that the switch valve 2 is used to manually control the release of the filling liquid 1, which is convenient for replacing new filling liquid. The filling liquid is XZZJ-J inorganic grouting reinforcement material for mining, which has the advantages of high fineness, good permeability, good early flowability, fast later strength growth, and can quickly fill small cracks; the external power supply 5 is used to provide power for the entire device, and the mounting bracket 6 is used to fix the entire device near the coal rock wall. The pressure signal of the air pressure valve 8 is converted into an electrical signal and transmitted to the display screen 3. When the display screen 3 receives the change signal transmitted by the air pressure valve 8, the signal is transmitted to the gas-liquid separation switch after analysis. The forward and reverse servo 10 in the gas-liquid separation switch rotates 180° after receiving the crack signal of the controller. After a period of time after the filling starts, the controller will control the servo 10 to rotate 180° every half hour. During this process, the filling liquid 1 is closed and the nitrogen 7 is opened. If the air pressure valve 8 does not change, it means that the crack has been filled and the nitrogen 7 remains continuous. Commonly used for crack detection; if the air pressure valve 8 changes, it means that the crack still exists. The controller controls the servo 10 to rotate 180° again, and repeats until the air pressure valve 8 does not change, that is, when the crack is completely filled, the nitrogen 7 continues to penetrate the coal rock mass for crack detection. The structural design of the central semicircular baffle 12, the outer semicircular baffle 13, the nitrogen baffle 15 and the slurry baffle 16 can realize that the filling liquid is closed when the nitrogen flows, and the nitrogen is closed when the filling liquid flows. When the servo 10 receives the signal, the central semicircular baffle 12 and the outer semicircular baffle 13 linked by the transmission shaft 11 rotate 180° at the same time. During the rotation of 180°, one of the nitrogen baffle 15 and the slurry baffle 16 in the external large tube is always closed and the other is opened. At the same time, the closed or opened signal will be transmitted to the display screen 3 through the signal, thereby helping the controller to make a judgment. Human intervention control can also be performed through the button 4 to ensure that the device can work safely and efficiently.

[0035] The second outer large tube 17-2 and the second inner small tube 18-2 of the gas-liquid coexisting grouting pipeline are connected and fixed by the plugging liquid injection pipeline 19. When the plugging liquid circulates, the plugging liquid that passes through the gas-liquid separation switch seeps into the coal rock cracks through the second inner small tube 18-2 and the plugging liquid injection pipe 19. When nitrogen circulates, it passes through the second outer large tube 17-2 and the second inner small tube 18-2 and is distributed throughout the coal rock through the surface micropores 20. Nitrogen is a colorless, odorless, non-toxic, non-corrosive gas with very good stability. It is simple to make, has low economic cost, and basically does not cause pollution to the environment. At the same time, the injection of nitrogen will also inhibit the oxidation of the coal. Therefore, the present invention uses nitrogen to detect whether there are cracks in the coal rock.

[0036] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention. Example

[0037] After the coal rock mass fissure self-repairing device of the present invention is installed, the nitrogen and plugging liquid switch valves are manually opened and the power is turned on. At this time, plugging liquid and nitrogen exist in the pipeline at the same time, but due to the effect of the gas-liquid separation switch, they will not mix. The real-time pressure data of the nitrogen pressure valve will be analyzed by the controller and displayed on the display screen. Nitrogen also runs through the entire device and contacts the coal rock wall through a large number of micropores in the gas-liquid coexistence grouting pipeline. If cracks occur in the coal rock wall, the flow rate in the nitrogen cylinder will change. The change in flow rate can be detected by the pressure valve, and the change data will be transmitted to the controller and displayed on the display screen at the same time for display. Relevant personnel record and analyze the data. After analyzing the data changes, the controller triggers the gas-liquid separation switch. The gas-liquid separation switch servo drives the transmission shaft to rotate 180°. At this time, the nitrogen in the pipeline is closed and the plugging liquid is opened. The plugging liquid is sprayed into the coal rock wall cracks through the plugging liquid injection pipe. After the cracks are plugged for a period of time, the control device controls the gas-liquid separation switch, the servo rotates 180°, the nitrogen is turned on, and the plugging liquid is turned off. At this time, if the nitrogen pressure valve still changes, the gas-liquid separation switch is started again, and plugging continues until the cracks are completely repaired; when the cracks are completely repaired, the nitrogen is turned on again, filling the entire system for crack detection.

[0038] The control device of the present invention is used to analyze the signals transmitted by the trigger and feedback system. When there is a crack signal, the gas-liquid separation switch is started. At the same time, the remaining amount of the nitrogen bottle and the filling liquid is monitored through the air pressure valve, and the remaining amount is displayed in real time; the gas-liquid separation switch turns on the steering gear after receiving the signal from the control device, and will operate in two modes: first, the nitrogen is turned off and the filling liquid is turned on to fill the cracks; secondly, the filling liquid is turned off and the nitrogen is turned on to monitor the cracks; the gas-liquid coexistence grouting pipeline can transport two substances in different states through one pipeline at the same time to ensure that the filling liquid is accurately filled to the position where the nitrogen leaks, and can monitor the cracks in the coal rock layer in real time and accurately fill them. The method of combining the filling liquid and nitrogen can accurately detect the cracks and fill them in time. The whole system can be used for a long time. This cyclic reciprocating detection-filling-detection method can minimize the generation of cracks inside the coal rock mass to the greatest extent and for the longest time. It is an innovation in the self-repairing device and repair method of coal rock mass cracks, and has good economic and social benefits.

[0039] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for self-repairing cracks in coal and rock mass, characterized in that: A coal rock mass fracture self-repairing device is used, the coal rock mass fracture self-repairing device includes a control device and a gas-liquid device, the control device (21) includes a bracket, a plugging liquid tank (1), a display screen (3), a nitrogen tank (7) and a controller (4), the bracket is equipped with a plugging liquid tank (1) and a nitrogen tank (7), the plugging liquid tank (1) is connected to the controller (4) via a first pipeline, the nitrogen tank (7) is connected to the controller (4) via a second pipeline, the controller (4) is connected to the display screen (3), the gas-liquid device is composed of a gas-liquid separation switch (22), a gas-liquid separation switch pipeline (23) and a gas-liquid separation switch pipeline (24). ) and a gas-liquid coexisting grouting pipeline (24), the gas-liquid separation switch (22) includes a forward and reverse steering gear (10), a transmission shaft (11), and a fixing frame (14), the forward and reverse steering gear (10) is mounted on the fixing frame (14), a central semicircular baffle (12) is mounted on the transmission shaft (11) of the forward and reverse steering gear (10), an outer semicircular baffle (13) is mounted on the central semicircular baffle (12), the forward and reverse steering gear (10) is connected to the controller (4), the gas-liquid separation switch (22) is mounted in the gas-liquid separation switch pipeline (23), the gas-liquid separation switch pipeline (23) includes a nitrogen baffle Plate (15), slurry baffle (16), first external large tube (17-1), first internal small tube (18-1), first external large tube (17-1) is equipped with first internal small tube (18-1), nitrogen baffle (15) is provided between first external large tube (17-1) and first internal small tube (18-1), slurry baffle (16) is provided on first internal small tube (18-1), gas-liquid separation switch pipe (23) is connected with gas-liquid coexisting grouting pipe (24), gas-liquid coexisting grouting pipe (24) includes second external large tube (17-2), A second internal small tube (18-2), a plugging liquid injection pipe (19), and surface micropores (20); the second internal small tube (18-2) is installed in the second external large tube (17-2); the second external large tube (17-2) is provided with surface micropores (20); a plurality of plugging liquid injection pipes (19) are provided between the second external large tube (17-2) and the second internal small tube (18-2); the fixing frame (14) is fixed on the first external large tube (17-1); the forward and reverse steering gear (10) and the transmission shaft (11) are installed in the first internal small tube (18-1); Then follow these steps: 1) The coal rock mass fracture self-repairing device is installed on a rock wall where fractures may occur, and a gas-liquid coexistence grouting pipeline (24) of appropriate length is selected according to the depth of the rock wall. A certain number of plugging liquid injection pipelines (19) are installed inside the pipeline, and the pipelines are connected to the control device through the gas-liquid separation switch pipeline and the gas-liquid separation switch; 2) When nitrogen leaks from a crack in the coal rock wall of the installed coal rock crack self-repairing device, the pressure signal of the air pressure valve (8) is converted into an electrical signal and transmitted to the display screen (3). When the display screen (3) receives the change signal transmitted by the air pressure valve (8), the signal is transmitted to the gas-liquid separation switch after analysis. The forward and reverse steering gear (10) of the gas-liquid separation switch rotates 180 degrees after receiving the crack signal from the controller, and shuts off the nitrogen by closing the outer semicircular baffle (13) and the nitrogen baffle (15); 3) opening the plugging liquid to perform plugging, the plugging liquid sequentially passes through the gas-liquid separation switch (22) and the gas-liquid separation switch pipe (23) into the gas-liquid coexistence grouting pipe (24), and seeps into the coal rock fissure through the plugging liquid injection pipe (19) provided in the gas-liquid coexistence grouting pipe (24); 4) After a period of time after the plugging begins, the controller controls the forward and reverse steering gear (10) to rotate 180 degrees every half an hour. During this process, the plugging liquid tank (1) is closed by closing the central semicircular baffle (12) and the slurry baffle (16), and the nitrogen tank (7) is opened. The nitrogen passes through the second outer large tube (17-2) and the second inner small tube (18-2) and is distributed throughout the coal rock through the surface micropores (20); 5) If the air pressure valve (8) does not change, it means that the crack has been completely filled and blocked, and the nitrogen tank (7) remains connected for crack detection. If the air pressure valve (8) changes, it means that the crack still exists, and the controller controls the forward and reverse steering gear (10) to rotate 180 degrees again. This is repeated until the air pressure valve (8) does not change. When the crack is completely filled and blocked, the nitrogen tank (7) continues to penetrate the coal rock mass for crack detection.

2. The coal rock mass crack self-repairing method according to claim 1, characterized in that: The first pipeline is equipped with a first switch valve (2), and the second pipeline is equipped with a second switch valve (9).

3. The method for self-repairing cracks in coal and rock mass according to claim 1, characterized in that: The nitrogen tank (7) is equipped with an air pressure valve (8).

4. The method for self-repairing cracks in coal and rock mass according to claim 1, characterized in that: The plugging liquid tank (1) is filled with a plugging liquid, which is XZZJ-J inorganic grouting reinforcement material for mining.

5. The method for self-repairing cracks in coal and rock mass according to claim 1, characterized in that: The second outer large tube (17-2) and the second inner small tube (18-2) are connected and fixed together through a plugging liquid injection pipe (19); a large number of micropores (20) are present on the surface of the outer large tube (17), and if there is no coal rock blocking the surface, a large amount of nitrogen can be released through the micropores (20).

6. The method for self-repairing cracks in coal and rock mass according to claim 1, characterized in that: The controller (4) and the display screen (3) are externally connected to a power supply (5), and the controller (4) is a PLC programmable logic controller.

7. The method for self-repairing cracks in coal and rock mass according to claim 1, characterized in that: The transmission shaft (11) extends into the first internal small tube (18-1) and is fixed thereto.

8. The method for self-repairing cracks in coal and rock mass according to claim 1, characterized in that: The diameters of the first outer large tube (17-1) and the second outer large tube (17-2) match each other, and the diameters of the first inner small tube (18-1) and the second inner small tube (18-2) match each other.

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