Coal mine gas extraction hole sealing device

Abstract

The utility model discloses a coal mine gas extraction hole sealing device in the technical field of hole packers, which comprises a gas pipe, a grouting pipe, a slurry return pipe and two hole sealing bags, the grouting pipe is provided with an explosion valve between the two hole sealing bags, the slurry return pipe extends to the position right above the explosion valve, and the gas pipe is connected with the gas pipe. A plurality of exhaust holes are formed in the bottom and the top of the part, located between the two hole sealing bags, of the slurry return pipe, and the slurry return pipe is vertically and slidably connected with a sealing plate used for sealing the exhaust holes in the bottom. According to the scheme, the multiple exhaust holes are formed in the top and the bottom of the slurry return pipe for exhausting, the exhaust speed is increased, and the injection speed of slurry in the closed space is increased; meanwhile, the sealing plate is upwards jacked up by the slurry to seal a plurality of exhaust holes in the bottom, so that the slurry is prevented from entering the slurry return pipe in advance to return slurry outwards or block the slurry, and air in the closed space is exhausted completely.

Description

Technical Field

[0001] This utility model relates to the field of sealing device technology, specifically to a sealing device for coal mine gas extraction. Background Technology

[0002] Currently, commonly used borehole sealing technologies for coal mine gas drainage include cement mortar sealing, polyurethane foam sealing, gas drainage plugging device sealing, and pressure-type expansion capsule sealing, among which pressure-type expansion capsule sealing is more widely used.

[0003] Referring to existing technology CN104343415A - Gas Drainage Borehole Inflation-Type Bag Sealing Device, it includes two sealing bags for sealing coal seam boreholes and gas drainage pipes, grouting pipes, and return grout pipes passing through their inner cavities. The sealing bags are spaced apart at both ends of the grouting pipes, forming at least one sealed space within the coal seam borehole. One-way rupture valves A are installed on the passageways within the sealing bags of the grouting pipes, and one-way rupture valves B are installed on the passageways within the sealed space. The rupture pressure of one-way rupture valve A is lower than that of one-way rupture valve B. By using the sealing bags and rupture valves, sealing grout is injected sequentially into the sealing bags and the sealed space between them. The sealing bags rapidly expand, ultimately resulting in a tight bond between the bags and the borehole wall, and between the grout in the sealed space and the borehole wall. Referring to the existing technology of mining sealing device - CN205858268U, it includes a sealing tube, a first-stage bladder, a second-stage bladder, a burst valve, a first grouting check valve, a second grouting check valve, and a drainage screen. The sealing tube is an internal tube type three-hole integrated pipe structure. The large hole inside the sealing tube is a gas drainage pipe, the small hole above the large hole is a grouting pipe, and the small hole below the large hole is an exhaust / return grouting pipe. The sealing tube is equipped with a first grouting check valve, a burst valve, and a second grouting check valve in sequence. The sealing tube passes through the first-stage bladder and the second-stage bladder in sequence. The first grouting check valve and the second grouting check valve are respectively located inside the first-stage bladder and the second-stage bladder.

[0004] The aforementioned existing technologies all utilize a return grout pipe to expel air from the sealed space, and similarly employ a rupture valve to inject grout into the sealed space. However, because the return grout pipe has only a single opening, the air expulsion speed is slow. If the opening is made larger, it will compress and occupy the sealed space, resulting in a smaller diameter for the gas extraction pipe and a slower gas extraction speed. Therefore, the air pressure will cause the grout injection speed within the sealed space to slow down. Adding multiple vents to the return grout pipe to increase the expulsion speed is problematic. However, as the grout is gradually poured upwards within the sealed space, it may prematurely enter the return grout pipe through the vents, causing blockages, or prematurely return through the return grout pipe while the air in the sealed space has not yet been completely expelled. This results in a large number of air bubbles forming gaps within the grout, affecting the filling effect of the sealing grout and also impacting the sealing performance. Utility Model Content

[0005] The present invention aims to provide a coal mine gas extraction sealing device to solve the problem in the prior art where the slurry return pipe is not vented in time, resulting in a slow injection speed of slurry in a confined space.

[0006] To solve the above problems, this utility model provides the following technical solution:

[0007] A coal mine gas extraction and sealing device includes a gas pipe, a grouting pipe, a return grouting pipe, and two sealing bags. The grouting pipe is provided with a burst valve between the two sealing bags. The return grouting pipe extends directly above the burst valve. The bottom and top of the portion of the return grouting pipe between the two sealing bags are provided with multiple vent holes. The return grouting pipe is vertically slidably connected to a sealing plate for sealing the multiple vent holes at the bottom.

[0008] The working principle and beneficial effects of this utility model:

[0009] In this method, the sealing device is inserted into the borehole of the coal seam, and pressurized grouting is performed through the grouting pipe. After grouting, the sealing bags expand and seal the borehole, forming a sealed space between adjacent sealing bags. Subsequently, the rupture valve opens under the grouting pressure, and grout is injected into the sealed space. At this time, the sealing plate does not seal the multiple vent holes at the bottom, so the air in the sealed space is discharged outward through the multiple vent holes.

[0010] As the grout is injected, the liquid level in the sealed space gradually rises, and the return grout pipe extends directly above the rupture valve. When the grout approaches the sealing plate, most of the air in the sealed space has already been expelled. Grouting continues, and the grout gradually pushes the sealing plate upward. Finally, the sealing plate slides upward and seals the multiple vent holes at the bottom of the return grout pipe. Grout continues to be injected upward until it returns outward through the vent holes at the top of the return grout pipe, indicating that the sealing of the sealed space is complete.

[0011] This solution uses multiple vent holes at the top and bottom of the return slurry pipe to expel air, thereby accelerating the venting speed and increasing the injection speed of slurry in the confined space. At the same time, the slurry pushes the sealing plate upward to seal the multiple vent holes at the bottom, preventing the slurry from entering the return slurry pipe prematurely and causing it to return outward or become blocked, thus ensuring that the air in the confined space is completely expelled.

[0012] The optimized sealing plate is an arc-shaped plate. The arc-shaped plate fits snugly against the return slurry pipe, resulting in a better seal for the bottom vent hole.

[0013] Preferably, the sealing plate is made of a plate with a density lower than that of the slurry. This density difference makes it easier for the slurry to lift the sealing plate.

[0014] Preferably, the sealing bag is a rubber sealing bag or a cloth sealing bag. Rubber sealing bags are elastic and easily deformable, and can better seal the drilled hole after grouting; cloth sealing bags are lightweight and easy to carry.

[0015] Preferably, the return slurry pipe is provided with a limiting groove, and the sealing plate is fixedly provided with a limiting block that is slidably connected to the limiting groove. The sealing plate is pulled upward using the limiting groove and the limiting block.

[0016] Preferably, the burst valve is located in the middle of the two sealed bags. This optimized design allows the slurry to be uniformly filled upwards into the sealed space. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the installation of a coal mine gas extraction sealing device according to the present invention.

[0018] Figure 2 for Figure 1 A schematic diagram of the structure when the middle sealing plate closes the bottom exhaust hole;

[0019] Figure 3 for Figure 1 Vertical cross-sectional view of the return slurry pipe;

[0020] Figure 4 for Figure 3 A schematic diagram of the structure when the middle sealing plate closes the exhaust port. Detailed Implementation

[0021] The following detailed description illustrates the specific implementation method:

[0022] The reference numerals in the accompanying drawings of the instruction manual include: 1. Drill hole; 2. Return grout pipe; 3. Gas pipe; 4. Grouting pipe; 5. Bursting valve; 6. Sealing plate; 7. Sliding rod; 8. Limiting block; 9. Vent hole.

[0023] In the following statements, directional terms such as "left," "right," "up," and "down" are based on the directions shown in the diagram. In practice, if the corresponding structures are changed in the same direction based on the direction while maintaining their relative positions, it will not affect the implementation of the plan.

[0024] Example: A coal mine gas drainage sealing device, such as Figure 1 and Figure 3 As shown, it includes a gas pipe 3, a grouting pipe 4, a return grouting pipe 2, and two sealing bags. The grouting pipe 4 is located between the two sealing bags and is equipped with a burst valve 5. The return grouting pipe 2 extends directly above the burst valve 5. The bottom and top of the part of the return grouting pipe 2 located between the two sealing bags are respectively provided with multiple exhaust holes 9.

[0025] The return pipe 2 is provided with a vertical sliding groove, and a sliding rod 7 is vertically slidably connected to the sliding groove. A limiting block 8 is fixedly provided at the top of the sliding rod 7 to prevent the sliding rod 7 from falling out of the sliding groove. A sealing plate 6 that seals multiple vent holes 9 at the bottom of the sliding rod 7 is fixedly sleeved at the bottom. In this embodiment, the sealing plate 6 is made of plastic, which has the characteristics of being lightweight and its density is less than that of the slurry (mud).

[0026] In this method, the sealing device is inserted into the borehole 1 of the coal seam, and pressurized grouting is performed through the grouting pipe 4. After grouting, the sealing bag expands and seals the borehole 1, forming a sealed space between adjacent sealing bags. Subsequently, the rupture valve 5 opens under the grouting pressure, and grout is injected into the sealed space. For details on how the grouting pipe 4 grouts the sealing bags and the working principle of the rupture valve 5, please refer to existing technologies such as CN104343415A-Gas Drill Hole Inflatable Bag Sealer and Mining Sealer-CN205858268U. At this time, the sealing plate 6 does not seal the multiple vent holes 9 at the bottom, so the air in the sealed space is discharged to the outside through the multiple vent holes 9.

[0027] like Figure 2 and Figure 4 As shown, the slurry gradually rises in the sealed space, and the return slurry pipe 2 extends directly above the rupture valve 5. When the slurry approaches the sealing plate 6, most of the air in the sealed space has been expelled. Then, the slurry continues to be injected. The density of the sealing plate 6 is less than that of the slurry, so the sealing plate 6 floats on the slurry. The slurry gradually pushes the sealing plate 6 upward. The sliding groove restricts the sliding rod 7 to slide only vertically. The sliding rod 7 slides vertically upward toward the inside of the return slurry pipe 2. Finally, the sealing plate 6 slides upward and seals the multiple vent holes 9 at the bottom of the return slurry pipe 2. Then, the slurry continues to be injected upward until the slurry returns to the outside through the vent holes 9 at the top of the return slurry pipe 2, which means that the sealing of the sealed space is completed.

[0028] This solution uses multiple vent holes 9 at the top and bottom of the return slurry pipe 2 to vent air, thereby accelerating the venting speed and increasing the injection speed of slurry in the confined space. At the same time, the slurry pushes the sealing plate 6 upward to seal the multiple vent holes 9 at the bottom, preventing the slurry from entering the return slurry pipe 2 in advance and returning or blocking it, so that the air in the confined space can be completely exhausted.

[0029] All standard parts used in this utility model can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art, and the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.

Claims

1. A coal mine gas drainage sealing device, comprising a gas pipe, a grouting pipe, a return grouting pipe, and two sealing bags, wherein the grouting pipe is provided with a rupture valve located between the two sealing bags, and the return grouting pipe extends directly above the rupture valve, characterized in that: The return slurry pipe is provided with multiple vent holes at the bottom and top of the portion between the two sealing bags, and the return slurry pipe is vertically slidably connected to a sealing plate for sealing the multiple vent holes at the bottom.

2. The coal mine gas extraction sealing device according to claim 1, characterized in that: The sealing plate is an arc-shaped plate.

3. The coal mine gas extraction sealing device according to claim 2, characterized in that: The sealing plate uses a plate with a density less than that of the slurry.

4. The coal mine gas drainage sealing device according to any one of claims 1 to 3, characterized in that: The sealed bag is specifically a rubber sealed bag or a cloth sealed bag.

5. The coal mine gas drainage sealing device according to claim 4, characterized in that: The return slurry pipe is provided with a limiting groove, and the sealing plate is fixedly provided with a limiting block that is slidably connected to the limiting groove.

6. The coal mine gas drainage sealing device according to claim 5, characterized in that: The burst valve is located in the middle of the two sealed bladders.

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