Coal seam roof cutting pressure relief hole structure and energy gathering pipe

Abstract

The utility model discloses a coal seam roof cutting pressure relief hole, which belongs to the technical field of coal mining, and comprises a caving area after goaf roof cutting, a local mining area support block, local mining area coal, a local mining area top plate and a next mining area top plate, and the local mining area top plate and the next mining area top plate are positioned above the local mining area coal. A circle of rib plate type mud strip is arranged on the inner wall of the tail end of an inner cavity of the drill hole in a surrounding mode, an orifice supporting assembly is arranged on the inner wall of an outer end opening of the inner cavity of the drill hole, and the orifice supporting assembly is fastened to the inner wall of an outer opening of the drill hole, so that the energy gathering pipe body is stable in the inner cavity of the drill hole and prevented from falling off. The drilling holes are formed in the top plate of the mining area and the top plate of the next mining area, directional blasting is conducted through the energy gathering pipe body, the caving direction and range of the top plates can be accurately controlled, the risk of sudden caving of the top plates is reduced, and threats to a mine structure and personnel safety caused by irregular rock stratum fracture are avoided.

Description

Technical Field

[0001] This utility model belongs to the field of coal mining technology, and in particular to a coal seam top cutting and pressure relief hole and energy-concentrating pipe. Background Technology

[0002] In coal mining, shaped charge blasting technology is an advanced blasting method that utilizes the shaped charge effect to effectively break up coal seams. A shaped charge, also known as a linear shaped charge or jet cutter, is a blasting device designed based on the principle of shaped charges. Its characteristics include generating a high-speed metal jet upon detonation, possessing strong penetrating power and concentrated energy release.

[0003] In coal mining, roof management is a crucial aspect of ensuring safe and efficient mine production. Traditional roof management methods primarily rely on natural caving, forced roof caving, and bolt support. However, these methods have several drawbacks. For instance, traditional methods struggle to precisely control the extent and direction of roof collapse, potentially leading to sudden, large-scale roof collapses and serious safety accidents. Furthermore, the securing of shaped charge tubes or other blasting devices within the borehole is often ineffective, leading to slippage or falling, resulting in failed blasting or poor blasting results. Utility Model Content

[0004] The purpose of this utility model is to provide a coal seam top cutting and pressure relief hole and a focusing tube to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a coal seam roof cutting and pressure relief hole, comprising a collapse zone after roof cutting in a goaf, a support block of the mining area, coal in the mining area, and the roof of the mining area and the roof of the next mining area located above the coal in the mining area. The roof of the mining area and the roof of the next mining area have drill holes. A ring of rib-type mud strips is surrounded on the inner wall of the inner end of the inner cavity of the drill hole. A hole opening support assembly is provided on the inner wall of the outer port of the inner cavity of the drill hole. The hole opening support assembly is fastened to the inner wall of the outer port of the drill hole, so that the energy-concentrating tube body is stable in the inner cavity of the drill hole and prevents it from falling off.

[0006] In a preferred embodiment of this solution, the orifice support assembly includes an orifice support sleeve that is clearance-fitted to the outer opening of the borehole and an orifice silicone sleeve that is interference-fitted to the outer periphery of the orifice support sleeve, wherein the orifice silicone sleeve is elastically pressed against the inner wall of the outer opening of the borehole.

[0007] In this preferred embodiment, two locking bolts are symmetrically connected through the inner wall of one end of the orifice support sleeve. These locking bolts pass through the orifice support sleeve and the orifice silicone sleeve, connecting to the inner wall of the drilled hole. This locks the orifice support sleeve at the outer opening of the drilled hole. Elastic compression between the orifice silicone sleeve and the inner wall of the drilled hole prevents slippage and detachment, further providing stable support for the energy-concentrating tube body and preventing it from falling. The inner end of the orifice support sleeve has an energy-concentrating tube sleeve opening, which is interference-fitted onto the outer wall of the first end of the energy-concentrating tube body.

[0008] A concentrating tube includes a concentrating tube body inserted into the borehole. When the concentrating tube body is inserted into the borehole, a ring of ribbed mud strips tightly wraps around the tail end of the concentrating tube body, so that the concentrating tube body is fastened in the borehole cavity.

[0009] In a preferred embodiment, the inner cavity of the shaped charge tube body is sequentially filled with front-end loess blasting mud, water blasting mud, detonator, and tail-end loess blasting mud along the borehole from the outside to the inside. The detonator is filled with explosives, and the outer side of the detonator is configured as the shaped charge tube wall.

[0010] In this preferred embodiment, the tail end loess slurry is located in the inner cavity of the tail end of the energy-concentrating tube body, and the tail end of the energy-concentrating tube body inserted into the borehole is detachably connected with a stable buffer tail cap.

[0011] In this preferred embodiment, the outer wall of the tail end of the energy-concentrating tube body has an external thread, and the inner wall of the stabilizing buffer tail cover has an internal thread that is threaded together with the external thread. After the stabilizing buffer tail cover is installed at the tail end of the energy-concentrating tube body, a buffer receiving cavity is formed inside.

[0012] In a preferred embodiment of this design, the buffer cavity is provided with an air spring and a compression spring sleeved around the air spring.

[0013] In this preferred embodiment, the two ends of the air spring and the compression spring are elastically abutted against the opposite sides of the energy-concentrating tube body and the stable buffer tail cap, respectively.

[0014] In this preferred embodiment, an anchor rod is welded to the outer wall of the stabilizing buffer cap on the side away from the energy-concentrating tube body. When the energy-concentrating tube body is inserted into the borehole, the anchor rod extends into the inner end of the borehole. This, under the action of the anchor rod, improves the stability of the energy-concentrating tube body in the borehole and prevents it from falling out.

[0015] Compared with the prior art, the technical effects and advantages of this utility model are as follows:

[0016] This coal seam roof-cutting and pressure-relief borehole and shaped charge tube, through drilling holes in the roof of this mining area and the roof of the next mining area, and using the shaped charge tube itself for directional blasting, can precisely control the direction and extent of roof collapse. This not only reduces the risk of sudden roof collapse, but also avoids the threat to mine structure and personnel safety posed by irregular rock fractures. The presence of the borehole can effectively release roof pressure and prevent roof accidents caused by pressure accumulation. This stress relief mechanism is particularly important in high-stress areas.

[0017] By rationally designing and arranging boreholes, the stability of the supporting blocks and coal in this mining area can be improved, reducing coal loss caused by excessive roof pressure. This helps to increase coal recovery rate and economic benefits. Traditional roof management methods may leave a large number of coal pillars to support the roof, while this technical solution, through controlled blasting, can reduce the number of coal pillars while ensuring safety, thereby improving the utilization rate of coal resources.

[0018] The design of the orifice support assembly and ribbed mud strips makes the installation of the ducting tube body simpler and faster. The orifice support assembly achieves a tight connection through locking bolts and orifice silicone sleeves, ensuring the stability of the ducting tube body in the borehole and reducing complex fixing procedures. Because the sealing and stability between the ducting tube body and the borehole are effectively guaranteed, waste caused by material leakage or displacement is reduced, lowering construction costs.

[0019] The robust buffer cap incorporates air springs and compression springs, providing additional shock absorption during the explosion. This reduces the impact of the shock on the orifice support components and other equipment, extending their service life. The use of anchor bolts further enhances the stability of the shaped charge tube, preventing it from slipping or falling during the explosion and protecting surrounding equipment and structures. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram showing the drilling position of this utility model;

[0022] Figure 2 This is a schematic diagram of the drilling process of this utility model;

[0023] Figure 3 This is a cross-sectional view of the energy-concentrating tube body of this utility model;

[0024] Figure 4 This is a schematic diagram of the orifice support sleeve and the energy-concentrating tube body of this utility model in a disassembled state.

[0025] Figure 5 This is a schematic diagram of the disassembled structure of the air spring of this utility model;

[0026] Figure 6 This is a schematic diagram of the connection structure of the orifice support sleeve of this utility model.

[0027] Explanation of reference numerals in the attached figures:

[0028] In the diagram: 1. Collapsed area after roof cutting in the goaf; 2. Support block of this mining area; 3. Coal of this mining area; 4. Roof of this mining area; 5. Roof of the next mining area; 6. Borehole; 7. Condensing tube body; 8. Rib-type mud strip; 9. Anchor bolt; 10. Orifice support assembly; 11. Detonating cord; 12. Front-end loess mud; 13. Water mud; 14. Detonator; 15. Explosive; 16. Condensing tube wall; 17. Tail-end loess mud; 18. Stabilizing buffer tail cap; 19. Orifice support sleeve; 20. Locking bolt; 21. Air spring; 22. Compression spring; 23. External threaded passage; 24. Orifice silicone sleeve; 25. Condensing tube sleeve opening. Detailed Implementation

[0029] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid confusion with the present invention.

[0030] Unless otherwise defined, the directions mentioned herein, such as up, down, left, right, front, back, inside, and outside, are based on the directions shown in the figures of this utility model, and are explained here together.

[0031] This embodiment provides, for example Figures 1 to 6The diagram illustrates a coal seam roof-cutting and pressure-relief hole, comprising a post-cutting collapse zone 1, a support block 2, coal seam 3, and the roof 4 and the next mining area roof 5 located above the coal seam 3. The post-cutting collapse zone 1 is a naturally or artificially induced subsidence area formed after coal mining. It helps alleviate pressure on the overlying strata and reduces the pressure impact on the underlying unmined coal seam, thus ensuring safe mining. The support block 2, as part of the support structure, supports and stabilizes the coal seam 3, preventing it from collapsing during mining and ensuring the safety of the working face. The coal seam 3 is the target resource, located below the support block 2 and above the roof 4. Through the rational design of pressure-relief holes and other measures, coal recovery can be improved and safety during mining can be ensured. The roof 4 and the next mining area roof 5 are located above the current mining layer and the next planned mining layer, respectively. Drill holes 6 are installed between them to reduce roof pressure, prevent roof collapse accidents, and also help optimize the mine ventilation system. Drill hole 6 penetrates the roof 4 of this mining area to the roof 5 of the next mining area, aiming to release roof pressure and avoid the danger caused by sudden roof collapse. The interior is filled with materials such as the shaped charge tube body 7, ribbed mud strips 8, front-end loess drilling mud 12, water-based drilling mud 13, detonators 14, and explosives 15, forming a complete blasting system for controlled stress release.

[0032] In this embodiment, the roof 4 of this mining area and the roof 5 of the next mining area have drill holes 6. A ring of ribbed mud strips 8 surrounds the inner wall of the inner end of the inner cavity of the drill hole 6. An orifice support assembly 10 is provided on the inner wall of the outer port of the inner cavity of the drill hole 6. The orifice support assembly 10 is fastened to the inner wall of the outer port of the drill hole 6, so that the shaped charge tube body 7 is stable in the inner cavity of the drill hole 6 and prevents it from falling off. The ribbed mud strips 8 are installed at the tail end of the drill hole 6 to seal it and prevent gas leakage in the event of an explosion. They also help to fix the shaped charge tube body 7 and ensure its stable position. The orifice support assembly 10 consists of an orifice support sleeve 19 and an orifice silicone sleeve 24. It is used to fix the position of the shaped charge tube body 7 and ensure its correct installation. It is also tightly connected by locking bolts 20 to ensure construction safety.

[0033] In this embodiment, the orifice support assembly 10 includes an orifice support sleeve 19 that is clearance-fitted to the outer opening of the drill hole 6 and an orifice silicone sleeve 24 that is interference-fitted to the outer wall of the orifice support sleeve 19. The orifice silicone sleeve 24 is elastically pressed against the inner wall of the outer opening of the drill hole 6.

[0034] In this embodiment, two locking bolts 20 are symmetrically connected through the inner wall of one end of the orifice support sleeve 19. The locking bolts 20 pass through the orifice support sleeve 19 and the orifice silicone sleeve 24 and connect to the inner wall of the drill hole 6. This locks the orifice support sleeve 19 at the outer opening of the drill hole 6. The elastic compression between the orifice silicone sleeve 24 and the inner wall of the outer opening of the drill hole 6 prevents slippage and detachment, thereby further providing stable support for the energy-concentrating tube body 7 and preventing it from falling. The inner end of the orifice support sleeve 19 has an energy-concentrating tube sleeve opening 25, which is interference-fitted onto the outer wall of the first end of the energy-concentrating tube body 7. The orifice support sleeve 19 is used to fix the position of the energy-concentrating tube body 7. The orifice silicone sleeve 24 elastically presses against the inner wall of the outer opening of the drill hole 6, enhancing the sealing and anti-slip performance of the orifice support assembly 10.

[0035] A shaped charge tube includes a shaped charge tube body 7 inserted into a borehole 6. When the shaped charge tube body 7 is inserted into the borehole 6, a ring of ribbed mud strips 8 securely wraps around the tail end of the shaped charge tube body 7, thus fixing the shaped charge tube body 7 firmly within the cavity of the borehole 6. The shaped charge tube body 7 is a specially designed tubular device containing explosive 15 and other auxiliary materials, capable of generating directional explosive energy upon detonation. This effectively cuts and breaks through hard rock, promoting the collapse of the roof in the intended manner, while simultaneously limiting the impact range of the shock wave and protecting the surrounding environment.

[0036] In this embodiment, the inner cavity of the shaped charge tube body 7, along the borehole 6, is sequentially filled with front-end loess drilling mud 12, water drilling mud 13, detonator 14, and rear-end loess drilling mud 17. The detonator 14 is filled with explosive 15, and its outer side forms the shaped charge tube wall 16. Both the front-end and rear-end loess drilling mud 12 and 17 are used to seal both ends of the shaped charge tube body 7, preventing the outward diffusion of explosive products and ensuring that energy is concentrated and released in a predetermined direction, thus improving blasting efficiency. The water drilling mud 13, placed after the front-end loess drilling mud 12, can absorb some of the heat generated by the explosion, lowering the temperature and reducing dust. It can also moisten the surrounding rocks, increasing moisture content and helping to suppress the risk of fire caused by the explosion. The shaped charge tube wall 16 serves as the outer shell of the shaped charge tube body 7, not only protecting the internal explosive 15 from external influences but also guiding energy to be concentrated and released in a specific direction during the explosion, improving the blasting effect.

[0037] In this embodiment, the tail end loess mud 17 is located in the inner cavity of the tail end of the shaped charge tube body 7. The tail end of the shaped charge tube body 7, which is inserted into the borehole 6, is detachably connected to a stabilizing buffer tail cap 18. This stabilizing buffer tail cap 18 is installed at the tail end of the shaped charge tube body 7 and has an air spring 21 and a compression spring 22 inside. It can provide additional buffering at the moment of explosion, reduce the vibration transmitted to the borehole support assembly 10, protect the borehole structure from damage, and at the same time help stabilize the shaped charge tube body 7 when it is inserted into the borehole 6 before detonation. It can provide buffering and shock absorption force and improve stability.

[0038] In this embodiment, the outer wall of the tail end of the energy-concentrating tube body 7 has an external thread 23, and the inner wall of the stabilizing buffer tail cap 18 has an internal thread that is threaded together with the external thread 23. After the stabilizing buffer tail cap 18 is installed at the tail end of the energy-concentrating tube body 7, a buffer receiving cavity is formed inside.

[0039] In this embodiment, an air spring 21 and a compression spring 22 sleeved around the air spring 21 are provided in the buffer cavity.

[0040] In this embodiment, the two ends of the air spring 21 and the compression spring 22 elastically abut against the opposite sides of the energy-concentrating tube body 7 and the stable buffer tail cap 18, respectively.

[0041] In this embodiment, an anchor rod 9 is welded to the outer wall of the stabilizing buffer cap 18 on the side away from the shaped charge tube body 7. When the shaped charge tube body 7 is inserted into the borehole 6, the anchor rod 9 extends into the inner end of the borehole 6. This enhances the stability of the shaped charge tube body 7 within the borehole 6, preventing it from falling out. While anchor rods are typically used to reinforce rock formations, in this embodiment, they are welded to the stabilizing buffer cap 18. When the shaped charge tube body 7 is inserted into the borehole 6, the anchor rod 9 further enhances its stability, preventing it from sliding or falling out.

[0042] Working principle:

[0043] Before construction of the coal seam roof-cutting pressure relief hole and energy-concentrating tube, a detailed geological exploration of the mining area is required to determine the coal seam thickness, roof lithology, and stress distribution. Based on the exploration results, the location, depth, and number of boreholes 6 are designed. Using specialized drilling equipment, boreholes 6 are drilled at the predetermined locations, ensuring that the borehole diameter and depth meet the design specifications. During drilling, care must be taken to maintain the integrity and smoothness of the borehole wall to facilitate the subsequent insertion of the energy-concentrating tube body 7. The borehole support sleeve 19 is fitted with a clearance fit at the outer opening of borehole 6. The borehole silicone sleeve 24 is fitted with an interference fit on the peripheral outer wall of the borehole support sleeve 19, allowing it to elastically press against the inner wall of the borehole 6, ensuring sealing and anti-slip performance. By passing the locking bolt 20 through the borehole support sleeve 19 and the borehole silicone sleeve 24 and connecting it to the inner wall of borehole 6, the borehole support assembly 10 is further reinforced to ensure its stability and reliability.

[0044] A certain amount of front-end loess mud 12 is filled at the front end of the shaped charge tube body 7 to seal the tube opening and prevent gas leakage during explosion. An appropriate amount of water-based mud 13 is filled after the front-end loess mud 12 to absorb the heat generated by the explosion, lower the temperature, reduce dust, and moisten the surrounding rocks to suppress the risk of fire. The detonator 14 is installed at a suitable position on the shaped charge tube body 7, ensuring it is correctly connected to the detonating wire 11 for remote detonation. Explosive 15 is filled around the detonator 14, ensuring its even distribution for optimal blasting effect. The shaped charge tube wall 16 is ensured to remain intact, enabling it to guide energy in a concentrated direction during explosion. The rear end of the shaped charge tube body 7 is filled with rear-end loess mud 17 to seal the tail and further secure the internal materials.

[0045] Carefully insert the assembled shaped charge tube body 7 into the borehole 6, ensuring it enters smoothly and reaches the predetermined depth. Once the shaped charge tube body 7 is fully inserted, the ribbed mud strip 8 will securely wrap around the tail end of the shaped charge tube body 7, ensuring it remains stable within the borehole 6 and does not fall out. The shaped charge tube sleeve 25 is then interference-fitted onto the outer wall of the head end of the shaped charge tube body 7, ensuring a tight connection with the borehole support sleeve 19.

[0046] Anchor bolt 9 is welded to the outer wall of the stabilizing buffer cap 18 on the side away from the shaped charge tube body 7. When the shaped charge tube body 7 is inserted into the borehole 6, the anchor bolt 9 extends and inserts into the inner end of the borehole 6, further enhancing the stability of the shaped charge tube body 7 and preventing it from sliding or falling off. The stabilizing buffer cap 18 is screwed into the external thread 23 at the tail end of the shaped charge tube body 7 to ensure a secure connection. An air spring 21 and a compression spring 22 are installed in the buffer receiving cavity inside the stabilizing buffer cap 18 to provide additional cushioning and reduce the transmission of the impact force during an explosion to the borehole support assembly 10.

[0047] One end of the detonating cord 11 is connected to the detonator 14, and the other end is led out to an operating point at a safe distance to ensure the safety of the detonation operation. After confirming that everything is ready, the detonator 14 is detonated via a remote detonation device, which in turn detonates the explosive 15. Guided by the wall 16 of the shaped charge tube 7, the explosive 15 generates directional explosive energy, cutting and destroying hard rock, causing the roof to collapse in the expected manner. The energy generated by the explosion is released through the borehole 6, effectively reducing the pressure on the roof 4 of this mining area and the roof 5 of the next mining area, preventing the danger caused by sudden roof collapse.

[0048] After blasting, the site should be cleaned up promptly, and residues removed to ensure the safety of the working face. Once safety is ensured, normal production operations should be resumed, and coal mining should continue.

[0049] It should be noted that, in this document, relational terms such as "one" and "two" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, the phrase "comprising an element defined as..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0050] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A coal seam roof cutting and pressure relief hole structure, comprising boreholes (6) formed in the roof of the current mining area (4) and the roof of the next mining area (5), characterized in that: A ring of ribbed mud strips (8) surrounds the inner wall of the inner cavity tail end of the borehole (6). A borehole support assembly (10) is provided on the inner wall of the outer port of the borehole (6). The borehole support assembly (10) includes a borehole support sleeve (19) with clearance fit to the outer port of the borehole (6) and a borehole silicone sleeve (24) with interference fit to the outer wall of the borehole support sleeve (19). The borehole silicone sleeve (24) is elastically pressed against the inner wall of the outer port of the borehole (6). Two locking bolts (20) are symmetrically connected through the inner wall of one end of the borehole support sleeve (19). The locking bolts (20) pass through the borehole support sleeve (19) and the borehole silicone sleeve (24) and are connected to the inner wall of the borehole (6). The borehole support assembly (10) is fastened to the inner wall of the outer port of the borehole (6) to support the energy-concentrating tube body (7) inserted therein and prevent it from falling off.

2. A focusing tube that is inserted into the coal seam roof cutting and pressure relief hole as described in claim 1, characterized in that, The energy-concentrating tube body (7) is inserted into the borehole (6). When the energy-concentrating tube body (7) is inserted into the borehole (6), a ring of ribbed mud strips (8) tightly wraps around the tail end of the energy-concentrating tube body (7), so that the energy-concentrating tube body (7) is fastened in the inner cavity of the borehole (6).

3. A focusing tube according to claim 2, characterized in that: The inner cavity of the shaped charge tube body (7) and along the borehole (6) from the outside to the inside are filled with front-end loess blasting mud (12), water blasting mud (13), detonator (14) and tail-end loess blasting mud (17). The detonator (14) is filled with explosive (15), and the outer side of the detonator (14) is set as the shaped charge tube wall (16).

4. A focusing tube according to claim 3, characterized in that: The tail end loess blasting mud (17) is located in the inner cavity of the tail end of the energy-concentrating tube body (7), and the tail end of the energy-concentrating tube body (7) inserted into the borehole (6) is detachably connected with a stable buffer tail cap (18).

5. A focusing tube according to claim 4, characterized in that: The outer wall of the tail end of the energy-concentrating tube body (7) has an external thread (23), and the inner wall of the stable buffer tail cap (18) has an internal thread that is threaded together with the external thread (23). After the stable buffer tail cap (18) is installed at the tail end of the energy-concentrating tube body (7), a buffer receiving cavity is formed inside.

6. A focusing tube according to claim 5, characterized in that: The buffer cavity is provided with an air spring (21) and a compression spring (22) sleeved around the air spring (21).

7. A focusing tube according to claim 6, characterized in that: The two ends of the air spring (21) and the compression spring (22) are elastically abutted against the opposite sides of the energy-concentrating tube body (7) and the stable buffer tail cap (18), respectively.

8. A focusing tube according to claim 7, characterized in that: An anchor rod (9) is welded to the outer wall of the side away from the energy-concentrating tube body (7). When the energy-concentrating tube body (7) is inserted into the borehole (6), the anchor rod (9) extends and is inserted into the inner end of the borehole (6).

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