Anchoring device and anchoring process based on post-mix abrasive ultra-high pressure water jet

Abstract

This invention belongs to the field of coal mining technology and relates to an anchor removal device and process based on post-mixed abrasive ultra-high pressure water jet. The device includes: an ultra-high pressure water jet cutter head; a rack, positioned below the ultra-high pressure water jet cutter head, with protruding teeth on its side; a rack conveyor, sleeved on the outside of the rack, with grooves on its inner wall matching the protruding teeth, for conveying the rack upwards or downwards; an abrasive storage tank connected to the ultra-high pressure water jet cutter head via an abrasive delivery pipeline; and an ultra-high pressure water pump connected to the ultra-high pressure water jet cutter head via a water supply pipeline. The anchor removal device of this invention achieves efficient anchor removal operations in confined spaces. Furthermore, during the anchor removal process, the space within the cutting gap and the space around the anchor rod are filled with water, creating a continuous low-oxygen, low-temperature environment. Even when the abrasive hits the anchor rod, no sparks are generated, effectively solving the safety problem caused by sparks easily generated during existing abrasive water jet anchor removal processes.

Description

Technical Field

[0001] This invention belongs to the technical field of coal mining equipment, and relates to an anchor removal device and process based on post-mixed abrasive ultra-high pressure water jet. Background Technology

[0002] In underground coal mining, goaf management is a crucial aspect of safe production. The total caving method, due to its advantages of strong adaptability, controllable cost, and simple operation, is the dominant technology for goaf roof management in underground coal mines. When using the total caving method to manage the goaf roof, the roof needs to collapse naturally within a controllable range to release surrounding rock stress. Unremoved anchor bolts create "forced support" on the roof, hindering its timely collapse and causing large-scale roof overhangs, triggering a series of chain-reaction safety hazards such as rock bursts and gas accumulation in the goaf. After anchor removal, the roof can collapse systematically along the "unsupported weak areas," transferring rock pressure to the deeper surrounding rock, which is beneficial for ensuring safe coal mine production.

[0003] With continuous technological advancements, high-pressure water jet technology has been increasingly applied to the removal of anchor bolts in coal mines. However, conventional high-pressure pure water jets, due to the limited density and hardness of water, often fail to effectively damage anchor bolts made of high-strength steel, thus failing to achieve the purpose of anchor removal. To overcome these problems, abrasive water jet technology has emerged. Existing abrasive water jet anchor removal processes employ pre-mixed abrasive water jet anchor removal technology, which involves pre-mixing abrasive with water before pressurizing and spraying it through a high-pressure pump. While this method enhances the cutting ability of the anchor bolt, it also introduces new problems.

[0004] First, the high-pressure abrasive-water mixture, when transported in pipelines, causes significant wear to the inner walls of the pipelines. If the pipelines rupture, the high-pressure abrasive can easily cause injuries or damage to underground equipment. Second, and more seriously, existing high-pressure abrasive waterjet anchor removal equipment can only cut exposed anchor bolts. When the abrasive hits metal objects, it generates sparks, which could trigger gas or coal dust explosions when used for underground anchor removal operations, posing a significant safety hazard.

[0005] Secondly, existing waterjet anchor removal equipment is often quite heavy, typically around 20 kg, requiring manual lifting and attachment to the roof with wire or chain before cutting and removing the anchor bolt. However, in underground coal mines, many work areas are quite confined, making the disassembly, assembly, and relocation of anchor removal equipment inconvenient, significantly reducing the efficiency of anchor removal operations. Furthermore, existing handheld small cutting equipment often has limited cutting height due to its handheld operation and is prone to vibration during the cutting process.

[0006] To address the aforementioned technical problems, this invention provides an anchor removal device and process based on post-mixed abrasive ultra-high pressure water jet. Summary of the Invention

[0007] In view of the above-mentioned technical problems, the present invention provides an anchor removal device and process based on post-mixed abrasive ultra-high pressure water jet, thereby solving the technical problems of the prior art, which has severe wear of abrasive pipelines, can only cut exposed anchor rods, and the abrasive hitting metal products will generate sparks, which may cause gas explosions or coal dust explosions when used for underground anchor removal operations, easily leading to major safety hazards.

[0008] To achieve the above objectives, the first aspect of the present invention provides an anchor removal device based on post-mixed abrasive ultra-high pressure water jet, comprising: an ultra-high pressure water jet cutter head; a rack disposed below the ultra-high pressure water jet cutter head, the rack having protruding teeth on its side; a rack conveyor sleeved on the outside of the rack, the rack having grooves on its inner wall matching the protruding teeth, for conveying the rack upward or downward; an abrasive storage tank connected to the ultra-high pressure water jet cutter head via an abrasive conveying pipeline; and an ultra-high pressure water pump connected to the ultra-high pressure water jet cutter head via a water supply pipeline.

[0009] Furthermore, the rack includes: a connecting rod with protruding teeth on its surface; a connecting protrusion at the first end of the connecting rod; and a connecting recess at the second end of the connecting rod, wherein the first end and the second end are the two ends of the connecting rod, and the connecting protrusion and the connecting recess match; when multiple connecting rods are connected sequentially, two adjacent connecting rods are connected through the connecting protrusion and the connecting recess; and bolt holes are formed in the connecting protrusion and the connecting recess, and two adjacent connecting rods are fixed by bolts.

[0010] Furthermore, the underground compressed air pipeline is connected to the abrasive storage tank to transport the abrasive with underground compressed air at a pressure of 0.4MPa-0.6MPa.

[0011] Furthermore, the anchor removal equipment also includes: a water storage tank connected to an ultra-high pressure water pump; a booster pump connected to an abrasive storage tank; and an air-water separator connected to both the booster pump and the underground compressed air pipeline to separate condensate in the underground compressed air pipeline, ensuring that the abrasive delivery pipeline and the abrasive storage tank are in a dry state.

[0012] Furthermore, the ultra-high pressure water jet cutter head includes: a cutter head block; a nozzle disposed on the side of the cutter head block; an upper protective cover disposed above the cutter head block; a cutter head rotating body disposed below the cutter head block; and a rack connecting block disposed below the cutter head rotating body and connected to the rack.

[0013] Furthermore, the cutter head block includes: a cutter head block outer shell; a cutter head inner sleeve disposed inside the cutter head block outer shell; a sand mixing chamber disposed inside the cutter head inner sleeve and connected to the nozzle; an energy-concentrating head disposed on the side of the sand mixing chamber and connected to both the sand mixing chamber and the ultra-high pressure water pump; and a sand inlet tungsten carbide sleeve disposed above the sand mixing chamber, connected to the sand mixing chamber, and connected to both the cutter head inner sleeve and the cutter head block outer shell.

[0014] Furthermore, the cutting head rotating body includes: a cutting head rotating body shell, disposed below the cutting head block; an adapter, disposed inside the cutting head rotating body shell and connected to the cutting head block shell; a high-pressure pipe adapter, passing through the adapter; and a high-pressure pipe rotary joint, disposed below the high-pressure pipe adapter and connected to the water storage tank via a water supply pipe, enabling the cutting head block to rotate relative to the water supply pipe, thereby driving the nozzle to rotate.

[0015] The second aspect of this invention provides an anchor removal process based on post-mixed abrasive ultra-high pressure water jet, applied to the anchor removal equipment based on post-mixed abrasive ultra-high pressure water jet provided in the first aspect. The steps of this anchor removal process include:

[0016] Step 1: Construction auxiliary drilling;

[0017] Step 2: The rack and pinion conveyor drives the ultra-high pressure water jet cutter head to extend into the auxiliary borehole;

[0018] Step 3: Adjust the water outlet direction of the ultra-high pressure water jet cutter head toward the anchor bolt;

[0019] Step 4: Turn on the ultra-high pressure water pump, and the ultra-high pressure water jet nozzle will spray out an ultra-high pressure water jet;

[0020] Step 5: Open the abrasive storage tank and use the underground compressed air to transport the abrasive to the ultra-high pressure water jet cutter head and mix it with the ultra-high pressure water jet. Under the siphon effect of the ultra-high pressure water jet, the abrasive is sprayed out from the ultra-high pressure water jet cutter head along with the ultra-high pressure water jet to form a post-mixed abrasive ultra-high pressure water jet.

[0021] Step 6: Using the rack as the axis, rotate the ultra-high pressure water jet cutter head first in the first direction, then in the second direction, and then in the first direction again, repeating the cycle to cut through the rock between the ultra-high pressure water jet cutter head and the anchor rod, forming a cutting gap.

[0022] Step 7: Continuously allow the post-mixed abrasive ultra-high pressure water jet to pass through the cutting gap, cut the anchor rod, and complete the anchor removal operation.

[0023] Furthermore, the auxiliary boreholes are set parallel to the anchor bolts; the width of the cutting gap is 3mm-5mm.

[0024] Furthermore, in step 6, the first direction and the second direction are opposite; if the first direction is clockwise, the second direction is counterclockwise; if the first direction is counterclockwise, the second direction is clockwise.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] (1) The anchor removal device based on post-mixed abrasive ultra-high pressure water jet of the present invention achieves efficient anchor removal operation by connecting the ultra-high pressure water jet cutter head to the rack and pinion. Moreover, during the anchor removal process, the cutting gap space and the space around the anchor rod are filled with water flow, forming a continuous low oxygen and low temperature environment. Even if the abrasive hits the anchor rod, it cannot generate sparks. This effectively solves the problem of sparks easily generated during the existing abrasive water jet anchor removal, thereby avoiding production accidents such as gas explosion or coal dust explosion that may be caused by the existing abrasive water jet anchor removal. This is of great significance for ensuring the safe production of coal mines.

[0027] (2) The ultra-high pressure water jet cutter head of the present invention is small in size and light in weight. By setting a rack and rack conveyor, the ultra-high pressure water jet cutter head is easy to lift or lower, and the lifting height can be accurately adjusted. The groove on the inner wall of the rack conveyor matches the convex teeth on the rack, and they can mesh with each other to ensure the stability of the cutting process under the condition of accurate height. This avoids the shortcomings of existing handheld small cutting equipment, which cannot be raised, have limited cutting height, and are unstable due to hand operation, which can easily cause the ultra-high pressure water jet cutter head to shake or vibrate, resulting in low cutting accuracy. Therefore, in the case of relatively small space in underground coal mines, the anchor removal device of the present invention has a wider range of applications, taking into account the ease of use, the flexibility of height adjustment, and the accuracy and stability of cutting.

[0028] (3) This invention uses post-mixed abrasive ultra-high pressure water jet technology for anchor removal. The abrasive and ultra-high pressure water are transported by their respective pipelines and then mixed in the mixing chamber. The power source for abrasive transport is downhole compressed air of 0.4MPa-0.6MPa, which realizes low-pressure abrasive transport. The abrasive transported by downhole compressed air effectively avoids the large wear on the inner wall of the pipeline when the high pressure fluid formed after the abrasive and water are transported in the pipeline. In addition, the pressure resistance of the water supply pipeline is 10 times higher than the water jet pressure. Even if the water supply pipeline is damaged due to squeezing or wear, the ultra-high pressure water will start to atomize at the damaged point and will not form a high pressure water jet. Moreover, there is no abrasive in the water supply pipeline, which can avoid the safety risks caused by high pressure abrasive after pipeline damage in the existing pre-mixed abrasive water jet anchor removal process, and ensure the safety of personnel in the anchor removal operation. Attached Figure Description

[0029] The present invention is described with reference to the following figures:

[0030] Figure 1 This is a schematic diagram of the anchor removal device based on post-mixed abrasive ultra-high pressure water jet according to the present invention;

[0031] Figure 2 In order to be in Figure 1 A cross-sectional view of section II;

[0032] Figure 3 This is a schematic diagram of the structure of the ultra-high pressure water jet cutter head of the present invention;

[0033] Figure 4 Is Figure 3 A schematic cross-sectional view of section II-II;

[0034] Figure 5 This is a schematic diagram of the structure of the cutting head block of the present invention;

[0035] Figure 6 This is a structural schematic diagram of the blade block of the present invention from another angle;

[0036] Figure 7 Is Figure 6 A schematic cross-sectional view of section III-III;

[0037] Figure 8 This is a schematic diagram of the rack structure of the present invention;

[0038] Figure 9 This is a structural schematic diagram of the rack of the present invention from another angle.

[0039] Explanation of reference numerals in the attached figures:

[0040] 1. Threaded connector; 2. Ultra-high pressure water jet cutter head; 3. Auxiliary drilling; 4. Rack; 5. Abrasive delivery pipeline; 6. Sand supply valve; 7. Abrasive storage tank; 8. Booster pump; 9. Air-water separator; 10. Ultra-high pressure water pump; 11. Water storage tank; 12. Filter; 13. Water supply pipeline; 14. Connecting rod; 15. Connecting protrusion; 16. Connecting recess; 17. Nozzle; 18. Cutting slit; 19. Post-mixed abrasive ultra-high pressure water jet; 20. Anchor bolt; 21. Anchor bolt drilling; 22. Anchoring section; 23. Rock mass; 24. Cutter head 25. Head block; 26. Cutter head rotating body; 27. Upper guard; 28. Rack connecting block; 29. ​​Adapter; 30. High-pressure pipe adapter; 31. High-pressure pipe connector sleeve; 32. High-pressure pipe connector nut; 33. High-pressure pipe rotary joint; 34. Cutter head rotating body shell; 35. Nut; 36. Screw; 37. Pneumatic quick-connect fitting; 38. Cutter head block shell; 39. Cutter head fastening nut; 40. Cutter head inner sleeve; 41. Energy-concentrating head; 42. Nozzle retaining ring; 43. Tungsten carbide inlet sleeve; 44. Mixing chamber; 45. Rack conveyor. Detailed Implementation

[0041] The technical solutions of this invention will now be clearly and completely described. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0042] In one possible embodiment, such as Figures 1 to 9 As shown, this embodiment provides an anchor removal device based on post-mixed abrasive ultra-high pressure water jet, including: an ultra-high pressure water jet cutter head 2; a rack 4, disposed below the ultra-high pressure water jet cutter head 2, with protruding teeth on its side; a rack conveyor 44, sleeved on the outside of the rack 4, with grooves on its inner wall matching the protruding teeth, for conveying the rack 4 upward or downward; an abrasive storage tank 7, connected to the ultra-high pressure water jet cutter head 2 via an abrasive conveying pipeline 5; and an ultra-high pressure water pump 10, connected to the ultra-high pressure water jet cutter head 2 via a water supply pipeline 13.

[0043] For example, the rack 4 is made of metal and is connected to the rack conveyor 44 to raise or lower the ultra-high pressure water jet cutter head 2, thereby adjusting the position of the ultra-high pressure water jet cutter head 2 in the auxiliary borehole 3, that is, to achieve accurate height adjustment.

[0044] For example, the rated flow rate of the ultra-high pressure water pump 10 is 3L / min-8L / min, and the rated discharge pressure is 200MPa-400MPa.

[0045] In one possible embodiment, such as Figure 8 and Figure 9 As shown, the rack 4 includes: a connecting rod 14 with protruding teeth on its surface; a connecting protrusion 15 disposed at the first end of the connecting rod 14; and a connecting recess 16 disposed at the second end of the connecting rod 14. The first end and the second end are the two ends of the connecting rod 14, and the connecting protrusion 15 matches the connecting recess 16. When multiple connecting rods 14 are connected in sequence, two adjacent connecting rods 14 are connected through the connecting protrusion 15 and the connecting recess 16; and bolt holes are formed in the connecting protrusion 15 and the connecting recess 16, and two adjacent connecting rods 14 are fixed by bolts.

[0046] For example, the connecting rod 14, the connecting protrusion 15 and the connecting recess 16 are integrally formed or welded together to ensure the connection strength between the three and to provide a guarantee of connection strength for pushing the ultra-high pressure water jet cutter head 2 to rise.

[0047] For example, such as Figure 8As shown, in this embodiment, the connecting protrusion 15 is a trapezoidal structural component, and the connecting recess 16 is a corresponding trapezoidal structural groove. The two match each other to achieve the connection between two adjacent racks 4. For example, according to the needs of anchor removal operations, the racks 4 are arranged vertically. If the connecting protrusion 15 of the upper connecting rod 14 faces downward, then the connecting recess 16 of the connected lower connecting rod 14 faces upward, and the two adjacent connecting rods 14 are connected end to end. Conversely, if the connecting recess 16 of the upper connecting rod 14 faces downward, then the connecting protrusion 15 of the connected lower connecting rod 14 faces upward, and the two adjacent connecting rods 14 can also be connected end to end. Furthermore, the specific shapes of the connecting protrusion 15 and the connecting recess 16 are not further limited here, as long as they can achieve the mutual connection of adjacent racks 4. For example, triangular, polygonal, or other snap-fit ​​connectors are all acceptable.

[0048] In one possible embodiment, such as Figure 1 As shown, the underground compressed air pipeline is connected to the abrasive storage tank 7, and the abrasive is transported with underground compressed air at 0.4MPa-0.6MPa.

[0049] For example, the ultra-high pressure water jet cutter head 2 is connected to the ultra-high pressure water pump 10 through the water supply pipeline 13, the ultra-high pressure water pump 10 is connected to the filter 12, and the filter 12 is connected to the water supply port in the coal mine.

[0050] For example, the ultra-high pressure water jet cutter head 2 is connected to the abrasive storage tank 7 through the abrasive conveying pipeline 5. The abrasive storage tank 7 is connected to the booster pump 8, the booster pump 8 is connected to the air-water separator 9, and the air-water separator 9 is connected to the coal mine underground compressed air pipeline interface. The underground compressed air of 0.4MPa-0.6MPa is used as the power source for abrasive conveying. While ensuring the efficiency of anchor removal operation, the risk of injury caused by high pressure abrasive during the anchor removal process of pre-mixed abrasive water jet in the prior art is avoided.

[0051] In one possible embodiment, such as Figure 1 As shown, the water storage tank 11 is connected to the ultra-high pressure water pump 10; the booster pump 8 is connected to the abrasive storage tank 7; and the air-water separator 9 is connected to both the booster pump 8 and the underground compressed air pipeline to separate the condensate in the underground compressed air pipeline, so that the abrasive conveying pipeline 5 and the abrasive storage tank 7 are both in a dry state.

[0052] For example, the water tank 11 is also equipped with a filter 12 to filter out impurities in the well water source, so that the water entering the ultra-high pressure water jet cutter head 2 is free of impurities, thus avoiding damage to the ultra-high pressure water jet cutter head 2 caused by impurities.

[0053] For example, the gas-water separator 9 separates the condensate in the downhole compressed air pipeline, so that the abrasive, the abrasive storage tank 7, and the abrasive delivery pipeline 5 are all in a dry state, ensuring the abrasive delivery efficiency.

[0054] In one possible embodiment, such as Figures 3 to 7 As shown, the ultra-high pressure water jet cutter head 2 includes: a cutter head block 24; a nozzle 17 disposed on the side of the cutter head block 24; an upper protective cover 26 disposed above the cutter head block 24; a cutter head rotating body 25 disposed below the cutter head block 24; and a rack connecting block 27 disposed below the cutter head rotating body 25 and connected to the rack 4.

[0055] For example, the cutter head block 24 is connected to the upper guard 26 by the nut 34 and the screw 35, which effectively protects the cutter head block 24 and prevents damage to the cutter head block 24 caused by falling gravel above the auxiliary drilling hole 3 or by squeezing and friction during the lifting process.

[0056] For example, the cutting head rotating body 25 and the cutting head block 24 are connected by threads, and a rubber ring is clamped between them to ensure sealing.

[0057] For example, such as Figure 7 As shown, a nozzle retaining ring 41 is fitted on the nozzle 17. The nozzle retaining ring 41 is made of tapered stainless steel or steel and is fastened by a fastening nut so that the nozzle 17 can withstand greater pressure and will not fall off.

[0058] For example, the rack connecting block 27 is connected to the cutter head rotating body 25 by bolts, thereby realizing the connection between the cutter head rotating body 25 and the rack 4, and realizing the lifting or lowering of the ultra-high pressure water jet cutter head 2 by the rack 4.

[0059] In one possible embodiment, such as Figures 3 to 7 As shown, the cutter head block 24 includes: a cutter head block outer shell 37; a cutter head inner sleeve 39 disposed inside the cutter head block outer shell 37; a sand mixing chamber 43 disposed inside the cutter head inner sleeve 39 and connected to the nozzle 17; a focusing head 40 disposed on the side of the sand mixing chamber 43 and connected to both the sand mixing chamber 43 and the ultra-high pressure water pump 10; and a sand inlet tungsten carbide sleeve 42 disposed above the sand mixing chamber 43, connected to the sand mixing chamber 43, and connected to both the cutter head inner sleeve 39 and the cutter head block outer shell 37.

[0060] For example, this embodiment also includes a threaded connector 1 for connecting the cutter head block housing 37 to the pneumatic quick-connect connector 36.

[0061] For example, the inner sleeve 39 of the cutter head is embedded in the cutter head block 24 through two O-rings and is fastened by threads to achieve a sealing effect.

[0062] For example, the mixing chamber 43 is embedded inside the cutter head inner sleeve 39 and fixed by a set screw, providing a mixing space for ultra-high pressure water and abrasive.

[0063] For example, the middle material of the energy-concentrating head 40 is made of high-hardness ruby. The setting of the diameter of the small hole in the middle of the ruby ​​is to pressurize the medium-pressure water provided by the ultra-high pressure water pump 10 to form the ultra-high pressure water jet required by the ultra-high pressure.

[0064] For example, the tungsten carbide infeed sleeve 42 improves the wear resistance of the cutter head block 24, thereby reducing the wear of the cutter head block 24 by the abrasive and increasing the service life of the cutter head block 24.

[0065] In one possible embodiment, such as Figures 3 to 7 As shown, the cutting head rotating body 25 includes: a cutting head rotating body shell 33, which is disposed below the cutting head block 24; an adapter 28, which is disposed inside the cutting head rotating body shell 33 and connected to the cutting head block shell 37; a high-pressure pipe adapter 29, which passes through the adapter 28; and a high-pressure pipe rotary joint 32, which is disposed below the high-pressure pipe adapter 29 and is connected to the water storage tank 11 through the water supply pipe 13, so that the cutting head block 24 can rotate relative to the water supply pipe 13, thereby driving the nozzle 17 to rotate.

[0066] For example, the adapter 28 connects the cutter head block 24 and the cutter head rotating body 25. Here, the adapter 28 is a component that drives the cutter head block 24 to rotate. Through electrical connection control, the cutter head rotating body 25 forms an adjustable angle whole. When performing anchor removal operations in different work scenarios, the ultra-high pressure water jet cutter head 2 can be adjusted to different rotation angles, thereby improving the applicability of the anchor removal equipment.

[0067] For example, the high-pressure pipe fitting sleeve 30 and the high-pressure pipe fitting nut 31 are provided to connect the high-pressure pipe adapter 29 and the high-pressure pipe rotary joint 32 and to provide a sealing function.

[0068] For example, the high-pressure pipe connector nut 31 and the high-pressure pipe rotary connector 32 are connected by a bearing. On the one hand, this ensures that the high-pressure pipe rotary connector 32, the internal high-pressure pipe, and the water supply pipe 13 remain stationary, thus ensuring both sealing and connection stability. On the other hand, it also allows the high-pressure pipe connector nut 31 to rotate relative to the high-pressure pipe rotary connector 32, and to rotate the high-pressure pipe adapter 29, adapter 28, cutter head block 24, and nozzle 17 together, thereby realizing the rotation of the ultra-high pressure water jet cutter head 2. In this embodiment, the power source for the rotation of the above-mentioned components is electric drive.

[0069] For example, the cutter head rotating body housing 33 is used for interconnection between the cutter head block 24 and the cutter head rotating body 25, and also serves to protect the high-pressure pipe rotary joint 32.

[0070] For example, the cutter head rotating body housing 33 and the cutter head block 24 are fixedly connected by bolts, and the bolt connection facilitates disassembly, improving the efficiency of maintenance or replacement of parts.

[0071] In one possible embodiment, this embodiment provides an anchor removal process based on post-mixed abrasive ultra-high pressure water jet, applied to the anchor removal equipment based on post-mixed abrasive ultra-high pressure water jet in any of the above embodiments. The process steps include:

[0072] Step 1: Construction auxiliary drilling 3;

[0073] Step 2: The rack 4 drives the ultra-high pressure water jet cutter head 2 to extend into the auxiliary drilling hole 3 via the rack conveyor 44;

[0074] Step 3: Adjust the water outlet direction of the ultra-high pressure water jet cutter head 2 toward the anchor rod 20;

[0075] Step 4: Turn on the ultra-high pressure water pump 10, and the ultra-high pressure water jet cutter head 2 will spray out an ultra-high pressure water jet;

[0076] Step 5: Open the abrasive storage tank 7 and use the underground compressed air to transport the abrasive to the ultra-high pressure water jet cutter head and mix it with the ultra-high pressure water jet. Under the siphon effect of the ultra-high pressure water jet, the abrasive is ejected from the nozzle 17 of the ultra-high pressure water jet cutter head 2 along with the ultra-high pressure water jet, forming the post-mixed abrasive ultra-high pressure water jet 19.

[0077] Step 6: With rack 4 as the axis, rotate the ultra-high pressure water jet cutter head 2 first in the first direction, then in the second direction, and then in the first direction again, repeating the cycle, so as to cut through the rock between the ultra-high pressure water jet cutter head 2 and the anchor rod 20 and form a cutting gap 18.

[0078] Step 7: Continuously allow the post-mixed abrasive ultra-high pressure water jet 19 to pass through the cutting gap 18, cut the anchor rod 20, and complete the anchor removal operation.

[0079] For example, in the actual anchor removal operation, when the anchor removal equipment of the present invention is applied in the anchor removal operation, the post-mixed abrasive ultra-high pressure water jet 19 can cut the anchor rod 20, and can also be used to cut the anchor cable, or other metal parts that need to be cut by the post-mixed abrasive ultra-high pressure water jet 19 in the anchor removal operation.

[0080] For example, in step 1, an auxiliary borehole 3 with a diameter of 94 mm and a length of at least 1000 mm is drilled at a distance of 100 mm-300 mm from the anchor bolt 20, parallel to the anchor bolt 20. This size and position facilitate the insertion of the ultra-high pressure water jet cutter head 2 into the auxiliary borehole 3 for anchor removal operations. Furthermore, the specific length of the auxiliary borehole 3 needs to be determined based on the actual location of the anchor removal operation.

[0081] Step 2: Connect the ultra-high pressure water jet cutter head 2 to the ultra-high pressure water pump 10 via the water supply pipeline 13 to ensure a power source. The rack and pinion conveyor 44 can raise or lower the rack 4, thereby adjusting the height of the ultra-high pressure water jet cutter head 2 within the auxiliary borehole 3 to meet the needs of anchor removal operations at different height positions.

[0082] The pressure resistance of the water supply pipeline 13 is 10 times higher than that of the water jet pressure. For example, the pressure resistance of the water supply pipeline is 4000MPa, while the water jet pressure is 200MPa-400MPa. With this design, even if the water supply pipeline 13 is damaged due to compression or wear, the ultra-high pressure water will atomize at the damaged point and will not form a high-pressure water jet. Moreover, there is no abrasive in the water supply pipeline 13, which avoids the safety risks caused by high-pressure abrasive after pipeline damage during the anchor removal process of existing premixed abrasive water jet anchor removal, thus ensuring the safe operation of personnel and equipment during the anchor removal operation.

[0083] Step 3: The ultra-high pressure water jet cutter head 2 can rotate relative to the water supply pipeline 13, thereby adjusting the water outlet direction of the ultra-high pressure water jet cutter head 2 to the anchor rod 20 in the anchor rod drill hole 21 below the anchoring section 22. The height difference between the position of the ultra-high pressure water jet 19 mixed with abrasive after spraying by the ultra-high pressure water jet cutter head 2 and the opening of the auxiliary drill hole 3 is 500mm-800mm.

[0084] Step 4: Turn on the ultra-high pressure water pump 10, and the water jet will be ejected from the ultra-high pressure water jet cutter head 2.

[0085] Step 5: Open the abrasive storage tank 7. The abrasive is transported by downhole compressed air to the mixing chamber 43 of the ultra-high pressure water jet cutter head 2 and mixed with the ultra-high pressure water jet. Under the siphon effect of the ultra-high pressure water jet, the abrasive is ejected from the ultra-high pressure water jet cutter head 2 along with the ultra-high pressure water jet, forming the post-mixed abrasive ultra-high pressure water jet 19.

[0086] For example, the water supply pressure is much higher than the abrasive supply pressure, such as 200MPa-400MPa for water supply and 0.4MPa-0.6MPa for abrasive supply. The ultra-high pressure water and abrasive are mixed inside the mixing chamber 43 of the ultra-high pressure water jet cutter head 2. The ultra-high pressure water jet is first ejected from the ultra-high pressure water jet cutter head 2, forming a siphon effect. Under the action of the siphon effect, the abrasive is ejected with the ultra-high pressure water jet, forming a post-mixed abrasive ultra-high pressure water jet 19. The mixing is more uniform, the energy efficiency ratio is higher, and the cutting efficiency is also higher, thereby achieving efficient anchor removal.

[0087] For example, the abrasive storage tank 7 is provided with a sand supply valve 6 for opening or closing the abrasive storage tank 7 to provide or stop the supply of abrasive.

[0088] Step 6: By rotating the ultra-high pressure water jet cutter head 2, for example, the post-mixed abrasive ultra-high pressure water jet 19 is first rotated counterclockwise by 15°, then clockwise by 30°, and then counterclockwise by 15°, and so on, the post-mixed abrasive ultra-high pressure water jet 19 is used to cut through the rock mass 23 between the ultra-high pressure water jet cutter head 2 and the anchor rod 20, and form a cutting gap 18 with a width of 3mm-5mm.

[0089] Step 7: Continuously turn on the post-mixed abrasive ultra-high pressure water jet 19 so that the post-mixed abrasive ultra-high pressure water jet 19 passes through the cutting gap 18 and cuts the anchor rod 20 until the anchor rod 20 is cut off, thus completing the anchor removal operation.

[0090] In one possible embodiment, such as Figure 1 and Figure 2 As shown, the auxiliary drill hole 3 is set parallel to the anchor rod 20; the width of the cutting gap 18 is 3mm-5mm.

[0091] For example, in this embodiment, the anchor rod 20 is placed vertically, so the auxiliary drilling 3 is also implemented vertically. Furthermore, since the ultra-high pressure water jet is ejected horizontally, the distance between the ultra-high pressure water jet and the anchor rod 20 being cut is minimized, which greatly improves the anchor removal efficiency.

[0092] For example, since the abrasive used in this embodiment is garnet sand of 60-100 mesh, correspondingly, during the spraying of the post-mixed abrasive ultra-high pressure water jet 19, the distance between the abrasive and the anchor rod 20 is 100mm-300mm, and the width of the cutting gap 18 is 3mm-5mm, so that the cutting force of the post-mixed abrasive ultra-high pressure water jet 19 reaches the maximum, thereby ensuring the cutting efficiency of the anchor rod 20.

[0093] In one possible embodiment, such as Figure 2 As shown, in step 6, the first direction and the second direction are opposite; when the first direction is clockwise, the second direction is counterclockwise; when the first direction is counterclockwise, the second direction is clockwise.

[0094] For example, by setting opposite rotation directions of the ultra-high pressure water jet cutter head 2, the post-mixed abrasive ultra-high pressure water jet 19 repeatedly cuts the anchor rod 20. Through this cutting method of repeated cutting in two opposite directions, continuous and repeated cutting of the anchor rod 20 is achieved. Furthermore, since the cutting force is generated by the continuous horizontal movement of the abrasive, while the anchor rod 20 is placed vertically, the two are always in a mutually perpendicular position, thus improving cutting efficiency.

[0095] For example, the continuous horizontal movement of the post-mixed abrasive ultra-high pressure water jet 19 cuts the anchor rod 20, ensuring that the post-mixed abrasive ultra-high pressure water jet 19 always cuts a brand new cut surface on the anchor rod 20. The horizontal movement carries the cut debris away from the anchor rod 20 being cut in the horizontal direction, avoiding the accumulation of debris at the same position on the anchor rod 20, and further improving the anchor removal efficiency.

Claims

1. An anchor removal device based on post-mixed abrasive ultra-high pressure water jet, characterized in that, include: Ultra-high pressure water jet cutter head; A rack is disposed below the ultra-high pressure water jet cutter head, and the side of the rack is provided with protruding teeth; A rack and pinion conveyor is fitted over the outside of the rack and has grooves on its inner wall that match the protruding teeth to transport the rack up or down. An abrasive storage tank is connected to the ultra-high pressure water jet cutter head via an abrasive delivery pipeline; An ultra-high pressure water pump is connected to the ultra-high pressure water jet cutter head via a water supply pipeline; The ultra-high pressure water jet cutter head includes: Blade block; A nozzle is disposed on the side of the cutter head block; An upper protective cover is positioned above the cutter head block; A rotating cutter head is positioned below the cutter head block; A rack connecting block is disposed below the cutter head rotating body and connected to the rack; The cutting head block includes: Cutter head casing; The inner sleeve of the cutter head is disposed inside the outer shell of the cutter head block; The sand mixing chamber is located inside the inner sleeve of the cutter head and is connected to the nozzle; The energy-concentrating head is located on the side of the sand mixing chamber and is connected to both the sand mixing chamber and the ultra-high pressure water pump. The tungsten carbide inlet sleeve is located above the sand mixing chamber, communicates with the sand mixing chamber, and is connected to both the inner sleeve of the cutter head and the outer shell of the cutter head block. The rotating cutter head includes: The cutter head rotating body housing is located below the cutter head block; An adapter is disposed inside the outer shell of the cutting head rotating body and is connected to the outer shell of the cutting head block; A high-pressure pipe adapter is inserted into the adapter. A high-pressure pipe rotary joint is located below the high-pressure pipe adapter and is connected to the water storage tank through a water supply pipe, allowing the cutter head block to rotate relative to the water supply pipe, thereby driving the nozzle to rotate.

2. The anchor removal device based on post-mixed abrasive ultra-high pressure water jet according to claim 1, characterized in that, The rack includes: The connecting rod has the aforementioned protruding teeth on its surface; A connecting protrusion is provided at the first end of the connecting rod; A connecting recess is provided at the second end of the connecting rod, wherein the first end and the second end are the two ends of the connecting rod, and the connecting protrusion matches the connecting recess; When multiple connecting rods are connected in sequence, two adjacent connecting rods are connected through the connecting protrusion and the connecting recess; Bolt holes are formed in the connecting protrusion and the connecting recess, and two adjacent connecting rods are fixed by bolts.

3. The anchor removal device based on post-mixed abrasive ultra-high pressure water jet according to claim 1, characterized in that, Also includes: The underground compressed air pipeline is connected to the abrasive storage tank to transport the abrasive with underground compressed air at a pressure of 0.4MPa-0.6MPa.

4. The anchor removal device based on post-mixed abrasive ultra-high pressure water jet according to claim 3, characterized in that, Also includes: A water storage tank is connected to the ultra-high pressure water pump; A booster pump is connected to the abrasive storage tank; The gas-water separator is connected to both the booster pump and the downhole compressed air pipeline to separate the condensate in the downhole compressed air pipeline, thereby keeping the abrasive conveying pipeline and the abrasive storage tank in a dry state.

5. An anchor removal process based on post-mixed abrasive ultra-high pressure water jet, applied to the anchor removal equipment based on post-mixed abrasive ultra-high pressure water jet as described in any one of claims 1 to 4, characterized in that, The steps of the anchor removal process include: Step 1: Construction auxiliary drilling; Step 2: The rack and pinion conveyor drives the ultra-high pressure water jet cutter head to extend into the auxiliary borehole. Step 3: Adjust the water outlet direction of the ultra-high pressure water jet cutter head toward the anchor bolt; Step 4: Turn on the ultra-high pressure water pump, and the ultra-high pressure water jet cutter head sprays out an ultra-high pressure water jet; Step 5: Open the abrasive storage tank and use the underground compressed air to transport the abrasive to the ultra-high pressure water jet cutter head and mix it with the ultra-high pressure water jet. Under the siphon effect of the ultra-high pressure water jet, the abrasive is sprayed out from the ultra-high pressure water jet cutter head along with the ultra-high pressure water jet to form a post-mixed abrasive ultra-high pressure water jet. Step 6: Using the rack as the axis, rotate the ultra-high pressure water jet cutter head first in the first direction, then in the second direction, and then in the first direction again, repeating the cycle to cut through the rock between the ultra-high pressure water jet cutter head and the anchor rod, forming a cutting gap. Step 7: Continuously pass the post-mixed abrasive ultra-high pressure water jet through the cutting gap to cut the anchor rod and complete the anchor removal operation.

6. The anchor removal process based on post-mixed abrasive ultra-high pressure water jet according to claim 5, characterized in that: The auxiliary borehole is set parallel to the anchor bolt; The width of the cut slit is 3mm-5mm.

7. The anchor removal process based on post-mixed abrasive ultra-high pressure water jet according to claim 5, characterized in that: In step 6, the first direction is opposite to the second direction; When the first direction is clockwise, the second direction is counterclockwise; When the first direction is counterclockwise, the second direction is clockwise.

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