Radial roadway closed gas comprehensive extraction pipeline and lapping method

Abstract

The present application relates to a kind of roadway radial closed gas comprehensive extraction pipeline and lap method;The roadway radial closed gas extraction pipeline is arranged in the inside of roadway, the inner wall of roadway is covered with a layer of impermeable concrete, including extraction screen pipe, wall extraction screen pipe, air duct, connecting hose and gas negative pressure extraction circuit;Wall extraction screen pipe and extraction screen pipe are double-layer, including inner layer screen pipe and outer layer screen pipe;Extraction screen pipe is inserted into the side wall and top of roadway radially, wall extraction screen pipe is arranged in the side wall and top of roadway, and is communicated with each other;Air duct is communicated with the inner layer screen pipe of wall extraction screen pipe;In the inside of roadway, it is sprayed to be covered with gas permeable concrete and impermeable concrete, the lap method can avoid gas leakage of extraction hole, ensure the extraction concentration of extraction hole gas, improve the extraction efficiency of gas in extraction hole;While gas in coal seam can be avoided to pass through rock layer and enter roadway, thereby affecting the air quality in roadway, cause the waste of gas resource.

Description

Technical Field

[0001] This invention relates to the technical field of coal mine gas extraction, and in particular to a radially closed integrated gas extraction pipeline for roadways and a connection method thereon. Background Technology

[0002] In coal mines, combustible gases (mainly methane) are often present in coal seams. When the gas concentration exceeds a certain range, explosions can easily occur during coal mining. Gas from the coal seam can permeate through the rock strata, entering the roadway via the loosened zone and the area around the extraction hole, causing air pollution and wasting gas resources. Therefore, gas extraction is necessary before coal mining operations to prevent gas explosions. Current gas extraction methods simply discharge gas into a negative pressure extraction circuit without completely isolating the gas from the air. This results in the gas concentration in the roadway easily exceeding the standard, and the extracted gas concentration is unstable, making it unusable directly. Purification of the extracted gas is required, further increasing the cost of gas extraction. Summary of the Invention

[0003] The purpose of this invention is to solve the above-mentioned problems and provide a radially enclosed integrated gas extraction pipeline for roadways and a connection method thereon.

[0004] The technical solution of this invention is: a radially closed gas extraction pipeline for roadways, which is installed inside the roadway and includes an extraction screen, a wall extraction screen, an air intake pipe, a connecting hose, and a gas negative pressure extraction circuit; the wall extraction screen is double-layered, including an inner screen and an outer screen; the wall extraction screens are installed on the side walls and top of the roadway and are interconnected; the air intake pipe is connected to the inner screen of the wall extraction screen and extends into the roadway. The extraction screen is connected to the inner screen of the wall extraction screen; there are several extraction screens, which are radially inserted into the inner wall of the roadway. The gas negative pressure extraction circuit is set inside the roadway, and the gas venting pipe is connected to the gas negative pressure extraction circuit through a connecting hose. The aforementioned wall extraction screen is installed between the impermeable concrete and the roadway sidewall.

[0005] Preferably, the extraction pipeline also includes a suspension rod; the suspension rod is vertically inserted into the sidewall of the roadway; the suspension rod is positioned above the gas negative pressure extraction circuit; the suspension rod suspends the gas negative pressure extraction circuit. Using a suspension rod to suspend the gas negative pressure extraction circuit can reduce the difficulty of laying the pipeline due to the slope of the ground in the roadway.

[0006] Preferably, the suspension rod uses an adjustable suspension device to suspend the gas negative pressure extraction circuit. A downhole gas extraction pipeline suspension device that is easy to readjust, disclosed in prior art (patent document CN217380636U), can be used to adjust the height of the gas negative pressure extraction circuit.

[0007] Preferably, the screen holes on the inner and outer layers of the wall extraction screen are staggered. The inner and outer layers of screens are not connected, preventing rock debris or dust from entering the inner layer and causing blockage. Furthermore, a support ring is provided between the inner and outer screen tubes. The support ring ensures that the axes of the inner and outer screen tubes coincide, resulting in greater stability after installation.

[0008] A method for connecting radially closed gas extraction pipelines in roadways, using permeable concrete and impermeable concrete; The connection method for radially closed gas drainage pipelines in coal seam roadways is as follows: The first step is to carve out roadways in the coal seam; The second step is to spray and cover the top and sidewalls of the tunnel with permeable concrete. The third step is to drill several extraction holes radially on the top and sidewalls of the tunnel; The depth of the extraction hole exceeds the loose zone of the roadway; The fourth step involves inserting a drainage screen pipe that reaches the bottom of the drainage hole inside the drainage hole, laying a wall drainage screen pipe on the surface of the permeable concrete, and connecting the drainage screen pipe with the inner layer screen pipe in the wall drainage screen pipe; installing several air intake pipes on the wall drainage screen pipe, connecting the air intake pipes with the inner layer screen pipes of the wall drainage screen pipe, and extending the air intake pipes into the roadway. The fifth step is to seal the extraction hole; The sealing section is located entirely outside the loosening zone of the roadway; The sixth step is to spray and cover the existing permeable concrete with another layer of permeable concrete, thick enough to completely bury the extraction screen pipe on the wall. Step 7: Spray a layer of impermeable concrete onto the surface of the permeable concrete. Step 8: Drive several suspension rods into the impermeable concrete, suspend the gas negative pressure extraction circuit on the suspension rods, and connect the gas vent pipe to the gas negative pressure extraction circuit through the connecting hose. The radial sealing gas extraction pipeline connection in the coal seam roadway has been completed; A method for connecting radially closed gas extraction pipelines in roadways, using permeable concrete and impermeable concrete; The connection method for radially sealed gas drainage pipelines in rock strata roadways is as follows: The first step is to carve out a tunnel in the rock strata near the coal seam; The second step is to spray and cover the top and sidewalls of the tunnel with permeable concrete. The third step is to drill several extraction holes radially on the top and sidewalls of the tunnel; The depth of the extraction holes exceeds the loosening zone of the roadway, and the depth of some extraction holes on the sidewalls and top of the roadway must reach the interior of the coal seam. The fourth step involves inserting a drainage screen pipe that reaches the bottom of the drainage hole inside the drainage hole, laying a wall drainage screen pipe on the surface of the permeable concrete, and connecting the drainage screen pipe with the inner layer screen pipe in the wall drainage screen pipe; installing several air intake pipes on the wall drainage screen pipe, connecting the air intake pipes with the inner layer screen pipes of the wall drainage screen pipe, and extending the air intake pipes into the roadway. The fifth step is to seal the extraction hole; The sealing section is located entirely outside the loosening zone of the roadway; the sealing section is sealed using cement mortar method, which simultaneously plugs the air leakage cracks in the loosening zone of the extraction hole.

[0009] The sixth step is to spray and cover the existing permeable concrete with another layer of permeable concrete, thick enough to completely bury the extraction screen pipe on the wall. Step 7: Spray a layer of impermeable concrete onto the surface of the permeable concrete. Step 8: Drive several suspension rods into the impermeable concrete, suspend the gas negative pressure extraction circuit on the suspension rods, and connect the gas vent pipe to the gas negative pressure extraction circuit through the connecting hose. The radial sealing gas extraction pipeline connection in the rock strata roadway has been completed.

[0010] Furthermore, the sealing section is sealed using the cement mortar method. Sealing methods mainly include the "polyurethane method," the "cement mortar method," and the "bag method"; among these, the cement mortar method has lower cost, simpler operation, and wider applicability.

[0011] The beneficial effects of this invention are as follows: The radially enclosed gas extraction pipeline and its connection method for roadways are as follows: The radially enclosed gas extraction pipeline is installed inside the roadway and includes a wall extraction screen, an air intake pipe, a connecting hose, and a gas negative pressure extraction circuit; the wall extraction screen and the extraction screen are double-layered, including an inner screen and an outer screen; the extraction screen is radially inserted into the sidewall and top of the roadway, and the wall extraction screens are installed on the sidewall and top of the roadway and are interconnected; the air intake pipe is connected to the inner screen of the wall extraction screen and extends into the roadway; the interior of the roadway is sprayed and covered with permeable concrete and impermeable concrete.

[0012] This laying method can prevent gas leakage from the extraction holes, ensure the gas extraction concentration in the extraction holes, and improve the gas extraction efficiency in the extraction holes; at the same time, it can prevent gas in the coal seam from entering the roadway through the permeable rock strata, thereby affecting the air quality in the roadway and causing a waste of gas resources. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overlapping of radially closed gas extraction pipelines in coal seam roadways in this invention; Figure 2 This is a schematic diagram of the overlapping of radially sealed gas extraction pipelines in rock strata roadways in this invention; Figure 3 This is the front view of the wall-mounted extraction screen. Figure 4 yes Figure 3 AA section view; In the diagram: 1. Rock strata, 2. Coal seam, 3. Roadway, 31. Loosening ring, 4. Permeable concrete, 5. Suspension rod, 6. Impermeable concrete, 8. Connecting hose, 9. Gas negative pressure extraction circuit, 10. Sealing section, 71. Gas gathering channel, 72. Extraction hole, 73. Gas venting pipe; 701. Outer sieve tube, 702. Inner sieve tube, 703. Support ring, 704. Sieve hole. Detailed Implementation

[0014] Example 1: See Figure 1-4 A radially enclosed gas extraction pipeline for roadways is provided inside the roadway. The pipeline includes an extraction screen, a wall extraction screen, an air intake pipe 73, a connecting hose 8, and a gas negative pressure extraction circuit 9. The wall extraction screen is double-layered, including an inner screen 702 and an outer screen 701. The wall extraction screens are located on the side walls and top of the roadway 3 and are interconnected. The air intake pipe 73 is connected to the inner screen 702 of the wall extraction screen and extends into the roadway 3. The extraction screen is connected to the inner screen 702 of the wall extraction screen; there are several extraction screens, which are radially inserted into the inner wall of the roadway; the extraction screens extend into the rock stratum 1 or coal seam 2 through extraction holes to extract the gas therein.

[0015] The gas negative pressure extraction circuit 9 is installed inside the roadway 3, and the air intake pipe 73 is connected to the gas negative pressure extraction circuit 9 through the connecting hose 8. The air intake pipe 73 is connected to the gas negative pressure extraction circuit 9 through the connecting hose 8, so that all the gas in the roadway is collected into the gas negative pressure extraction circuit 9.

[0016] The aforementioned wall extraction screen is installed between the impermeable concrete 6 and the roadway sidewall. A three-way rotary valve is installed at the connection point between the ends of the wall extraction screen. The protruding end of the three-way rotary valve should be higher than the thickness of the shotcrete coverage on the wall, but not to obstruct valve rotation. The negative pressure inside the wall extraction screen is adjusted by rotating the valve to ensure the concentration of gas extracted from the wall. The impermeable concrete 6 covers the sidewall of roadway 3, preventing gas from penetrating the rock of the roadway sidewall or entering roadway 3 through the loosened ring of the borehole.

[0017] The extraction pipeline also includes a suspension rod 5; the suspension rod 5 is vertically inserted into the side wall of the roadway 3; the suspension rod 3 is positioned above the gas negative pressure extraction circuit 9; the suspension rod 5 suspends the gas negative pressure extraction circuit 9. Using the suspension rod 5 to suspend the gas negative pressure extraction circuit 9 can avoid the difficulty of laying the pipeline due to the slope of the ground in the roadway 3.

[0018] The suspension rod 5 uses an adjustable suspension device to suspend the gas negative pressure extraction circuit 9. It adopts the structure disclosed in patent document CN217380636U (A Suspension Device and System for Downhole Gas Extraction Pipeline Easily Readjustable). The height of the gas negative pressure extraction circuit 9 can be adjusted.

[0019] The screen holes 704 on the inner screen 702 and the outer screen 701 of the wall extraction screen are staggered. This prevents rock cuttings, coal dust, ash, or concrete from entering the inner screen 702 during roadway wall construction. A support ring 703 is provided between the inner screen tube 702 and the outer screen tube 701. The support ring 703 enables the axes of the inner and outer screen tubes to coincide, making the installation more stable and preventing debris from falling into the inner screen tube 702.

[0020] Example 2: See Figure 1 A method for connecting radially sealed gas extraction pipelines in a roadway, as described in Embodiment 1, utilizes permeable concrete and impermeable concrete. The connection method for radially closed gas drainage pipelines in coal seam roadways is as follows: The first step is to excavate roadway 3 in coal seam 2; The second step is to spray and cover the top and sidewalls of tunnel 3 with permeable concrete 4. The third step is to drill several extraction holes 72 radially on the top and sidewalls of tunnel 3; The depth of extraction hole 72 exceeds the loosening zone 31 of roadway 3; Long-term extraction practice has led to three types of sealing depths: ① The sealing section is located within the loosened zone of the roadway to ensure the longest possible coal seam exposure surface for extracting more gas. However, under the negative pressure of extraction, air in the roadway can easily enter the hole through the leakage fissures within the loosened zone, and this method is currently less commonly used; ② The sealing section extends beyond the loosened zone at the front end and is located within the loosened zone at the rear end. This method extracts as much gas as possible while ensuring the extraction hole is leak-proof, but gas accumulation at the hole opening is likely. This method is currently more commonly used; ③ The sealing section is completely outside the loosened zone of the roadway to ensure the extraction hole is leak-proof, thereby extracting high-concentration gas. However, depressurized gas within the loosened zone is not effectively extracted. Therefore, borehole extraction screens are used to extract deep gas from coal and rock strata, while wall extraction screens are used to extract gas seeping into the loosened zone of the roadway.

[0021] The fourth step is to insert an extraction screen pipe with a length reaching the bottom of the extraction hole 72 inside the extraction hole 72, and lay a wall extraction screen pipe on the surface of the permeable concrete 4. The extraction screen pipe is connected to the inner screen pipe 702 in the wall extraction screen pipe. Several air intake pipes 73 are set on the wall extraction screen pipe. The air intake pipes 73 are connected to the inner screen pipe 702 in the wall extraction screen pipe. The air intake pipes 73 extend into the roadway 3. Fifth step: Seal the extraction hole 72; The sealing section 10 is completely outside the loosening zone 31 of the roadway.

[0022] To seal leaking fissures in the loosened zone of boreholes, the main sealing methods include the polyurethane method, the cement mortar method, and the bag method. The polyurethane method involves sealing the front and rear ends of the extraction screen with polyurethane, and then injecting sufficient polyurethane into the sealed space in the middle. The cement mortar method involves injecting expanding cement grout under pressure into the sealed space in the middle. The bag method involves placing bags at the front and rear ends of the extraction screen, injecting grout into them to expand, and then injecting cement grout under pressure into the space between the two bags. Through pressurized grouting, the polyurethane or cement grout is forced into the external fissures, and after solidification, it seals the leaking fissures. The cement mortar method is relatively low-cost and widely used; therefore, this embodiment uses the cement mortar method for sealing.

[0023] The sixth step involves spraying another layer of permeable concrete 4 onto the surface of the existing permeable concrete 4, thick enough to completely bury the wall extraction screen. Burying the perforated wall extraction screen inside the permeable concrete fixes its position. The wall extraction screen is a double-layered screen, with densely packed perforations on both the inner and outer layers, allowing for the extraction of gas seeping from the extraction holes. This double-layered structure prevents the outer screen from being blocked by the sprayed permeable concrete, or allows rock debris to fall into the inner screen, thus affecting gas extraction.

[0024] Step 7: Spray a layer of impermeable concrete onto the surface of the permeable concrete; this will isolate the seeping gas from the space inside the tunnel, preventing the gas from entering the tunnel 3 through the rock on the sidewall of the tunnel or through the loosened ring of the borehole.

[0025] Step 8: Drive several suspension rods 5 into the impermeable concrete 6, suspend the gas negative pressure extraction circuit 9 on the suspension rods 5, and connect the gas vent pipe 73 to the gas negative pressure extraction circuit 9 through the connecting hose 8. The radial sealing gas extraction pipeline connection in the coal seam roadway has been completed; Example 3: See Figure 2 An example of a method for connecting radially sealed gas extraction pipelines in a roadway, using permeable concrete and impermeable concrete: The connection method for radially sealed gas drainage pipelines in rock strata roadways is as follows: The first step is to excavate a roadway 3 in the rock strata 1 near coal seam 2; The second step is to spray and cover the top and sidewalls of tunnel 3 with permeable concrete 4. The third step is to drill several extraction holes 72 radially on the top and sidewalls of tunnel 3; The depth of extraction hole 72 exceeds the loosening zone 31 of roadway 3; the depth of some extraction holes 72 on the sidewall and top of roadway 3 reaches the interior of coal seam 2. Gas is mainly distributed inside and near the coal seam. Opening extraction holes inside and near the coal seam can improve the efficiency of gas extraction and the concentration of extracted gas.

[0026] The fourth step is to insert an extraction screen pipe with a length reaching the bottom of the extraction hole 72 inside the extraction hole 72, and lay a wall extraction screen pipe on the surface of the permeable concrete 4. The extraction screen pipe is connected to the inner screen pipe 702 in the wall extraction screen pipe. Several air intake pipes 73 are set on the wall extraction screen pipe. The air intake pipes 73 are connected to the inner screen pipe 702 in the wall extraction screen pipe. The air intake pipes 73 extend into the roadway 3. Fifth step: Seal the extraction hole 72; The sealing section 10 is completely outside the loosening zone 31 of the roadway.

[0027] The sixth step is to spray and cover the surface of the existing permeable concrete 4 with another layer of permeable concrete 4, the thickness of which can completely bury the wall extraction screen. Step 7: Spray a layer of impermeable concrete onto the surface of the permeable concrete. Step 8: Drive several suspension rods 5 into the impermeable concrete 6, suspend the gas negative pressure extraction circuit 9 on the suspension rods 5, and connect the gas vent pipe 73 to the gas negative pressure extraction circuit 9 through the connecting hose 8. The radial sealing gas extraction pipeline connection in the rock strata roadway has been completed; Example 4: Example 4 is basically the same as Example 2 and Example 3, and the similarities will not be repeated. The difference is that the sealing section 10 is sealed using the polyurethane method. The sealing methods mainly include the "polyurethane method", "cement mortar method" and "bag method".

Claims

1. A radially enclosed gas extraction pipeline for a roadway, the pipeline being installed inside the roadway, the inner wall of the roadway being covered with a layer of impermeable concrete, characterized in that: This includes extraction screens, wall-mounted extraction screens, air intake pipes, connecting hoses, and negative pressure gas extraction circuits. The extraction screen and the wall extraction screen are double-layered, consisting of an inner screen and an outer screen. The wall extraction screens are installed on the side walls and top of the roadway and are interconnected; the air intake pipe is connected to the inner screen of the wall extraction screen and extends into the roadway. The extraction screen is connected to the inner screen of the wall extraction screen; there are several extraction screens, which are radially inserted into the inner wall of the roadway. The gas negative pressure extraction circuit is set inside the roadway, and the gas venting pipe is connected to the gas negative pressure extraction circuit through a connecting hose. The aforementioned wall extraction screen is installed between the impermeable concrete and the roadway sidewall.

2. The radially enclosed gas extraction pipeline for roadways according to claim 1, characterized in that: It also includes a suspension rod; the suspension rod is vertically inserted into the sidewall of the roadway; the suspension rod is set above the gas negative pressure extraction circuit; the suspension rod suspends the gas negative pressure extraction circuit.

3. The radially enclosed gas extraction pipeline for roadways according to claim 2, characterized in that: The suspension rod uses an adjustable suspension device to suspend the gas negative pressure extraction circuit.

4. The radially enclosed gas extraction pipeline for roadways according to claim 1, characterized in that: The screen holes on the inner and outer layers of the wall extraction screen tube are staggered.

5. The radially enclosed gas extraction pipeline for roadways according to claim 1, characterized in that: A support ring is provided between the inner and outer sieve tubes.

6. A method for connecting a radially sealed gas extraction pipeline in a roadway as described in claim 1, characterized in that: Use permeable concrete and impermeable concrete; The connection method for radially closed gas drainage pipelines in coal seam roadways is as follows: The first step is to carve out roadways in the coal seam; The second step is to spray and cover the top and sidewalls of the tunnel with permeable concrete. The third step is to drill several extraction holes radially on the top and sidewalls of the tunnel; The depth of the extraction hole exceeds the loose zone of the roadway; The fourth step involves inserting a drainage screen pipe that reaches the bottom of the drainage hole inside the drainage hole, laying a wall drainage screen pipe on the surface of the permeable concrete, and connecting the drainage screen pipe with the inner layer screen pipe in the wall drainage screen pipe; installing several air intake pipes on the wall drainage screen pipe, connecting the air intake pipes with the inner layer screen pipes of the wall drainage screen pipe, and extending the air intake pipes into the roadway. The fifth step is to seal the extraction hole; The sealing section is located entirely outside the loosening zone of the roadway; the sealing section is sealed using cement mortar method, which simultaneously plugs the air leakage cracks in the loosening zone of the extraction hole; The sixth step is to spray and cover the existing permeable concrete with another layer of permeable concrete, thick enough to completely bury the extraction screen pipe on the wall. Step 7: Spray a layer of impermeable concrete onto the surface of the permeable concrete. Step 8: Drive several suspension rods into the impermeable concrete, suspend the gas negative pressure extraction circuit on the suspension rods, and connect the gas vent pipe to the gas negative pressure extraction circuit through the connecting hose. The radial sealing gas extraction pipeline connection for the coal seam roadway has been completed.

7. A method for connecting a radially sealed gas extraction pipeline in a roadway as described in claim 1, characterized in that: Use permeable concrete and impermeable concrete; The connection method for radially sealed gas drainage pipelines in rock strata roadways is as follows: The first step is to carve out a tunnel in the rock strata near the coal seam; The second step is to spray and cover the top and sidewalls of the tunnel with permeable concrete. The third step is to drill several extraction holes radially on the top and sidewalls of the tunnel; The depth of the extraction holes exceeds the loosening zone of the roadway, and the depth of some extraction holes on the sidewalls and top of the roadway must reach the interior of the coal seam. The fourth step involves inserting a drainage screen pipe that reaches the bottom of the drainage hole inside the drainage hole, laying a wall drainage screen pipe on the surface of the permeable concrete, and connecting the drainage screen pipe with the inner layer screen pipe in the wall drainage screen pipe; installing several air intake pipes on the wall drainage screen pipe, connecting the air intake pipes with the inner layer screen pipes of the wall drainage screen pipe, and extending the air intake pipes into the roadway. The fifth step is to seal the extraction hole; The sealing section is located entirely outside the loosening zone of the roadway; the sealing section is sealed using cement mortar method, which simultaneously plugs the air leakage cracks in the loosening zone of the extraction hole; The sixth step is to spray and cover the existing permeable concrete with another layer of permeable concrete, thick enough to completely bury the extraction screen pipe on the wall. Step 7: Spray a layer of impermeable concrete onto the surface of the permeable concrete. Step 8: Drive several suspension rods into the impermeable concrete, suspend the gas negative pressure extraction circuit on the suspension rods, and connect the gas vent pipe to the gas negative pressure extraction circuit through the connecting hose. The radial sealing gas extraction pipeline connection in the rock strata roadway has been completed.

8. The method for connecting radially sealed gas extraction pipelines in roadways according to any one of claims 6-7, characterized in that: The sealing section is sealed with cement mortar.

Images