Hydraulic pressure relief and impact reduction system for coal seam under mine

Abstract

The utility model discloses a hydraulic pressure relief and impact reduction system for a coal seam under a mine, which is used for hydraulic pressure relief of a drill hole and comprises a drill bit, a high-low pressure converter, a high-pressure jet device and a high-pressure sealing drill rod which are sequentially connected from right to left. The high-pressure sealing drill rod comprises a plurality of drill rod sections, the last drill rod section is connected with a high-pressure rubber pipe at an outlet of a high-pressure pump through a rotary connector, the high-pressure rubber pipe comprises a plurality of rubber pipe sections, every two adjacent rubber pipe sections are connected and subjected to pressure relief through a tee joint and a pressure relief valve, and a gas-water-coal cinder separator is installed at an orifice of a drill hole. According to the coal seam hydraulic pressure relief system, pressure relief is conducted on a coal seam high-stress area in a coal seam hydraulic pressure relief mode, so that the coal seam impact danger is reduced, and safe operation of a mine is guaranteed.

Description

Technical Field

[0001] The utility model relates to the field of coal mining, in particular to a hydraulic pressure relief and impact reduction system for coal seams in mines. Background Art

[0002] Rock burst is a dynamic phenomenon in which energy accumulated in coal and rock masses around mine tunnels and mining areas is suddenly released. In severe cases, it can cause damage to the support system and casualties. Especially in the mining process of coal seams with high gas and high coal dust, strengthening the unloading and shock reduction of high-stress areas of coal seams is one of the main means to reduce the manifestation of rock burst, and it is also the top priority to ensure the safety of workers and the safe production of enterprises.

[0003] The traditional method of using explosive blasting to eliminate stress concentration in coal seams poses safety risks, necessitating a safer, more efficient, and greener coal seam pressure relief technology. Hydraulic coal seam pressure relief and shock reduction measures involve hydraulically cutting and cavitating coal seam boreholes, creating numerous new fractures within the coal seam. This effectively reduces the stress, gas internal energy, and elastic properties of the coal body, thereby increasing coal seam permeability and preventing sudden impacts. This is a safe, green, and efficient coal seam pressure relief technology that improves the efficiency and safety of coal mining and can be used to rapidly relieve pressure and reduce shock in high-stress coal seams in mines subject to rock burst pressure. Utility Model Content

[0004] In response to the above-mentioned technical deficiencies, the purpose of this utility model is to provide a hydraulic pressure relief and impact reduction system for coal seams in mines, which relieves pressure in high-stress areas of coal seams through hydraulic pressure relief to reduce the risk of coal seam impact and ensure safe operation in mines.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] The utility model provides a hydraulic pressure relief and shock reduction system for coal seams in mines, which is used for hydraulic pressure relief of drilling holes. The system comprises a drill bit, a high-low pressure converter, a high-pressure ejector and a high-pressure sealed drill rod which are sequentially connected from right to left. The high-pressure sealed drill rod comprises a plurality of drill rod sections and the last drill rod section is connected to a high-pressure hose at the outlet of a high-pressure pump via a rotary joint. The high-pressure hose comprises a plurality of hose sections, and two adjacent hoses are connected and pressure relieved by using a tee and a pressure relief valve. An air-water coal slag separator capable of allowing the high-pressure sealed drill rod to pass through is installed at the orifice of the borehole. The air-water coal slag separator is connected to an external gas extraction system via a gas extraction pipe.

[0007] Furthermore, the selection criteria for the high-pressure pump are that the maximum working pressure is not less than 60 MPa and the maximum water flow rate is not less than 125 L / min.

[0008] Furthermore, the length of the high-pressure sealed drill rod must ensure that the length of the mining borehole can penetrate the entire working surface.

[0009] Furthermore, the borehole construction diameter is 113mm. According to the actual situation on site, the borehole is constructed with a gentle inclination to optimize the diffusion of water flow in the coal seam and enhance the pressure relief effect;

[0010] Furthermore, the high-pressure ejector can eject high-pressure water to perform a sweeping cut and slag removal along the coal body along the hole wall. The high-low pressure converter allows the passage of static pressure water during the drilling process, and restricts the flow of high-pressure water during the hydraulic pressure relief process, allowing it to be ejected through the high-pressure ejector nozzle and thus damage the coal wall.

[0011] Furthermore, hydraulic coal seam pressure relief and shock reduction utilizes high-pressure water as the impact force source and a drilling and cutting integrated drill bit. By controlling the duration and pressure of the high-pressure water's interaction with the hole wall, the depth of the slot formation is controlled, ultimately forming a flat slot with a certain width and depth perpendicular to the drilling direction. The resulting slot is equivalent to mining a very thin protective layer within a localized area of ​​the coal seam, effectively relieving the high-stress area around the slot within a certain range, thereby achieving the purpose of shock reduction.

[0012] Furthermore, the drilling rig is used to hydraulically depressurize the borehole in a backward manner, and the depressurization step is repeated until the coal body is stopped at 30m away from the hole mouth, completing the construction of the entire section of the borehole;

[0013] Furthermore, the hydraulic pressure relief time is generally 15 to 20 minutes, and the pressure is controlled at 20 to 40 MPa;

[0014] Furthermore, the borehole should be flushed immediately for 3 to 5 minutes after the hydraulic pressure relief operation is completed to prevent coal rock dust from blocking the borehole and causing blowout accidents.

[0015] Furthermore, during the cutting operation, the gas-water coal slag separator should be connected to the gas extraction system for extraction.

[0016] The beneficial effects of the present invention are: the system realizes the integration of coal seam drilling, water injection and cutting processes, has high integration, simple operation and high operating efficiency, effectively reduces the stress, gas internal energy and coal body elastic energy of the coal seam, and then eliminates coal seam bursts and prevents impacts. It is a safe, green and efficient coal seam pressure relief technology, which can be used to quickly guide coal seam pressure relief on site in impact mine pressure mines. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 The present invention provides a structural schematic diagram of a hydraulic pressure relief and shock reduction system for coal seams in underground mines.

[0019] Description of reference numerals:

[0020] 1-drill bit; 2-high-low pressure converter; 3-high-pressure ejector; 4-high-pressure sealed drill pipe; 5-gas-water-cinder separator; 6-rotary joint; 7-high-pressure hose; 8-high-pressure pump; 9-tee; 10-pressure relief valve; 11-gas extraction pipe; 12-borehole; 13-working surface; 14-slot. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0022] like Figure 1 As shown, this embodiment provides a hydraulic pressure relief and shock reduction system for coal seams in mines, which is used for hydraulic pressure relief of a borehole 12, and includes a drill bit 1, a high-low pressure converter 2, a high-pressure ejector 3 and a high-pressure sealed drill pipe 4 connected in sequence from right to left. The high-pressure sealed drill pipe 4 includes several sections of drill pipe and the last section of drill pipe is connected to a high-pressure hose 7 at the outlet of a high-pressure pump 8 through a rotary joint 6. The high-pressure hose 7 includes several sections of hose, and two adjacent hoses are connected and pressure-relieved by a tee 9 and a pressure relief valve 10. An air-water coal slag separator 5 is installed at the orifice of the borehole 12, and the air-water coal slag separator 5 is connected to an external gas extraction system through a gas extraction pipe 11.

[0023] When performing hydraulic pressure relief and shock reduction operations on coal seams, the front end drill rod of the high-pressure sealed drill rod 4 is connected to the drill bit 1, the high-low pressure converter 2 and the high-pressure ejector 3, and the rear end drill rod is connected to the static pressure water through the rotary joint 6. An air-water coal slag separator 5 is installed at the mouth of the borehole 12. The high-pressure sealed drill rod 4 and the drill bit 1 are driven by the drilling rig to construct a borehole 12 in the middle of the side of the working face 13, the length of which runs through the entire working face 13; the diameter of the borehole 12 is 113 mm, and a gently inclined borehole is constructed according to the on-site conditions to optimize the diffusion of water in the coal seam and enhance the pressure relief effect.

[0024] Disconnect the static pressure water, connect the last drill pipe to the high-pressure hose 7 and high-pressure pump 8 via the rotary joint 6, start the drilling rig, and slowly rotate the high-pressure sealed drill pipe 4. Simultaneously, start the high-pressure pump 8 to pump high-pressure water into the borehole 12. Using the high-pressure water as the impact force, the high-pressure sealed drill pipe 4 drives the high-pressure ejector 3 to eject high-pressure water, which begins to sweep and cut the high-stress areas in the coal seam along the borehole wall, removing slag. By controlling the duration and pressure of the high-pressure water's interaction with the borehole wall, the depth of the slot 14 formed is controlled. The high-pressure pump 8 can operate at a maximum pressure of 60 MPa and a maximum water flow rate of 125 L / min. A hydraulic decompression cycle typically lasts 15 to 20 minutes, with a pressure controlled between 20 and 40 MPa. The hydraulic decompression radius is expected to be 0.3 to 0.5 m. Ultimately, a flat slot 14 of a certain width and depth is formed perpendicular to the borehole 12, ensuring sufficient decompression of the high-stress areas surrounding the slot 14 within a certain range, thereby achieving the goal of reducing impact. Finally, the high-pressure pump 8 is turned off and the pipeline is depressurized through the pressure relief valve 10. After the pressure relief is completed, the drilling rig uses the high-pressure sealed drill pipe 4 to repeat the hydraulic pressure relief and shock reduction until the coal cutting is stopped at 30 meters from the hole mouth, completing the hydraulic pressure relief construction of the entire borehole 12.

[0025] Obviously, those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if such modifications and variations fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include such modifications and variations.

Claims

1. A hydraulic pressure relief and shock reduction system for coal seams in underground mines, used for hydraulic pressure relief of drilling holes (12), characterized by: The invention comprises a drill bit (1), a high-low pressure converter (2), a high-pressure ejector (3) and a high-pressure sealed drill rod (4) connected in sequence from right to left. The high-pressure sealed drill rod (4) comprises a plurality of drill rod sections and the last drill rod section is connected to a high-pressure hose (7) at the outlet of a high-pressure pump (8) via a rotary joint (6). The high-pressure hose (7) comprises a plurality of hose sections. Two adjacent hoses are connected and pressure-relieved using a tee (9) and a pressure relief valve (10). An air-water coal slag separator (5) is installed at the orifice of the borehole (12) to allow the high-pressure sealed drill rod (4) to pass through. The air-water coal slag separator (5) is connected to an external gas extraction system via a gas extraction pipe (11).

2. The hydraulic pressure relief and shock reduction system for coal seams in underground mines according to claim 1, characterized in that: The selection criteria of the high-pressure pump (8) are that the maximum working pressure is not less than 60 MPa and the maximum water flow rate is not less than 125 L / min.

3. The hydraulic pressure relief and shock reduction system for coal seams in underground mines according to claim 2, characterized in that: The drill bit (1) is a drilling and cutting integrated drill bit.

4. The hydraulic pressure relief and shock reduction system for coal seams in underground mines according to claim 3, characterized in that: The length of the high-pressure sealing drill rod (4) must ensure that the length of the mining borehole (12) can penetrate the entire working surface.

5. The hydraulic pressure relief and shock reduction system for coal seams in underground mines according to claim 1, characterized in that: The high-pressure rubber hose (7) comprises two sections of rubber hose.

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