A rock-breaking device and method combining liquid nitrogen jet and particle impact.

Abstract

This invention belongs to the field of rock drilling technology, specifically relating to a rock-breaking device and method combining liquid nitrogen jet and particle impact. The rock-breaking device includes a liquid nitrogen jet fracturing system and a particle impact system. The liquid nitrogen jet fracturing system includes at least a liquid supply component and a hollow drill rod. The liquid supply component provides pressurized liquid nitrogen to the hollow drill rod, which has multiple liquid nitrogen nozzles arranged circumferentially. The hollow drill rod is used to inject liquid nitrogen into the rock mass through the liquid nitrogen nozzles in a borehole on the rock wall. The particle impact system includes a particle acceleration component and particle nozzles. The particle acceleration component accelerates the particles and propels them onto the rock wall near the borehole through the particle nozzles. This rock-breaking device not only eliminates the wear problem of traditional mechanical rock-breaking tools but also greatly improves drilling efficiency. Furthermore, this rock-breaking device enables a completely waterless operation, and the liquid nitrogen leaves virtually no residue after vaporization, making the rock-breaking process safer and more environmentally friendly.

Description

Technical Field

[0001] This invention belongs to the field of rock drilling technology, specifically relating to a rock-breaking device and method using liquid nitrogen jet combined with particle impact. Background Technology

[0002] In coal seam mining and underground tunneling operations, hard rock is inevitably encountered. Common rock-breaking methods include drill-and-blast and mechanical rock-breaking. Drill-and-blast involves pre-drilling blast holes, filling them with explosives, and then detonating them. Mechanical rock-breaking involves using mechanical rock-breaking devices to apply a concentrated external load to the rock mass, causing it to break. Mechanical rock-breaking offers advantages such as greater safety and efficiency, and has become the mainstream method in underground engineering construction.

[0003] However, traditional mechanical rock-breaking methods lead to accelerated tool wear when breaking hard rock. This not only directly affects construction efficiency, but also makes tool replacement prone to causing engineering accidents such as excavation face instability and coal and rock strata collapse. How to reduce tool wear while achieving good rock-breaking effect is the bottleneck problem for realizing efficient rock drilling.

[0004] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Invention Content

[0005] The purpose of this invention is to provide a rock-breaking device and method that combines liquid nitrogen jet and particle impact, so as to at least solve the above-mentioned problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A rock-breaking device combining liquid nitrogen jet and particle impact, the rock-breaking device comprising a liquid nitrogen jet fracturing system and a particle impact system;

[0008] The liquid nitrogen jet fracturing system includes at least a liquid supply assembly and a hollow drill pipe. The liquid supply assembly is used to supply pressurized liquid nitrogen to the hollow drill pipe. The hollow drill pipe is provided with multiple liquid nitrogen nozzles in its circumferential direction. The hollow drill pipe is used to inject liquid nitrogen into the rock mass through the liquid nitrogen nozzles in the borehole on the rock wall.

[0009] The particle impact system includes a particle acceleration component and a particle nozzle. The particle acceleration component is used to accelerate particles and spray the particles onto the rock wall near the borehole through the particle nozzle.

[0010] In the rock-breaking device of liquid nitrogen jet combined with particle impact as described above, preferably, the front end of the hollow drill rod is connected to a drill bit, and a bridge plug and a packer are spaced apart on the hollow drill rod behind the drill bit, and the liquid nitrogen nozzle is located on the hollow drill rod between the bridge plug and the packer.

[0011] In the rock-breaking device of liquid nitrogen jet combined with particle impact as described above, preferably, the liquid supply component includes at least a self-pressurizing liquid nitrogen storage tank and a liquid nitrogen buffer tank, which are connected by a first pipeline. The self-pressurizing liquid nitrogen storage tank is used to fill the hydraulic buffer tank with liquid nitrogen, and a first solenoid valve is provided on the first pipeline.

[0012] In the rock-breaking device combining liquid nitrogen jet and particle impact as described above, preferably, the liquid supply assembly further includes a liquid pump, which is located downstream of the buffer tank and is used to pressurize the liquid nitrogen in the liquid nitrogen buffer tank into a liquid nitrogen jet.

[0013] The inlet of the liquid pump is connected to the liquid nitrogen buffer tank via a second pipeline, on which a second solenoid valve is installed.

[0014] In the rock-breaking device combining liquid nitrogen jet and particle impact as described above, preferably, the driving source of the liquid pump includes a frequency converter control box, a motor and a transmission box, the output end of the motor is connected to the input end of the transmission box, and the output end of the transmission box is connected to the input shaft of the liquid pump; the frequency converter control box is connected to the motor and is used to control the speed of the motor.

[0015] In the rock-breaking device combining liquid nitrogen jet and particle impact as described above, preferably, a third pipeline is connected to the outlet of the liquid pump, and a third solenoid valve and a pressure gauge are installed on the third pipeline; the third pipeline is connected to multiple hollow drill rods through a branch pipe, so that the liquid pump can simultaneously deliver pressurized liquid nitrogen jets to multiple hollow drill rods.

[0016] In the rock-breaking device of liquid nitrogen jet combined with particle impact as described above, preferably, the particle acceleration component includes a particle acceleration tube, an impact rod, an air compressor and a gas cylinder, and the impact rod is guided to move in the particle acceleration tube.

[0017] The gas cylinder is connected to the air compressor via a pipeline for supplying gas to the air compressor. A gas cylinder valve is installed on the pipeline between the gas cylinder and the air compressor.

[0018] The air compressor is connected to the particle acceleration tube via a pipeline and is used to supply compressed gas to the particle acceleration tube.

[0019] The rock-breaking device combining liquid nitrogen jet and particle impact as described above, preferably, the particle acceleration component further includes a particle filling mechanism, the particle filling mechanism including at least a sleeve and an inner tube, the inner tube being disposed inside the sleeve and connected to one side of the particle acceleration tube for supplying particles to the particle acceleration tube;

[0020] One side of the inner tube is connected to a particle chamber via a pipe, and the particle chamber is used to replenish particles into the inner tube.

[0021] In the rock-breaking device of liquid nitrogen jet combined with particle impact as described above, preferably, the lower part of the casing is provided with a base, the inner tube extends into the base, the lower part of the inner tube is provided with a bottom plate, a guide sealing pad is provided in the inner tube, a spring is provided between the pad and the bottom plate, and multiple particles are supported above the pad.

[0022] The particle filling mechanism also includes a vacuum pump, and a fourth pipeline is provided between the vacuum pump and the particle acceleration tube. A fourth solenoid valve is provided on the fourth pipeline for controlling the reset of the impact rod.

[0023] A fifth pipeline is provided between the vacuum pump and the base plate. The fifth pipeline passes through the base plate and extends into the inner tube. A fifth solenoid valve is provided on the fifth pipeline for compressing the spring.

[0024] This application also provides a rock-breaking method using liquid nitrogen jet combined with particle impact, wherein the rock-breaking method uses the aforementioned liquid nitrogen jet combined with particle impact rock-breaking device, and the rock-breaking method includes the following steps:

[0025] Step 1: First, drill multiple holes in the rock wall, and then insert multiple hollow drill rods connected to the fluid supply assembly into one of the holes.

[0026] Step 2: Open the first solenoid valve to allow the self-pressurized liquid nitrogen storage tank to deliver a set amount of liquid nitrogen to the liquid nitrogen buffer tank, and then close the first solenoid valve.

[0027] Step 3: Open the second and third solenoid valves and turn on the liquid pump. The liquid pump pressurizes the liquid nitrogen in the liquid nitrogen buffer tank into a liquid nitrogen jet and then transmits it to the hollow drill rod. The liquid nitrogen jet is sprayed into the rock mass through the liquid nitrogen nozzle on the hollow drill rod and continuously sprays liquid nitrogen into the rock mass at a set pressure for a set time.

[0028] Step 4: Open the gas cylinder valve, start the air compressor to compress the gas and transmit it to the particle acceleration tube. The impact rod moves at high speed along the particle acceleration tube under the action of high-pressure air to impact the particles, causing the particles to be ejected at high speed from the particle nozzle and sprayed onto the rock wall between the four boreholes to break the rock mass; open the fourth solenoid valve and start the vacuum pump to reset the impact rod; then repeat the above process to make the particles repeatedly impact and break the rock wall.

[0029] Step 5: When the particles in the inner tube are used up, open the fifth solenoid valve and the particle valve, and start the vacuum pump to press down the spring on the pad. At this time, the particles in the particle chamber are replenished into the inner tube.

[0030] Step 6: Repeat steps 1-5 until the set rock excavation task is completed.

[0031] Beneficial effects:

[0032] In this rock-breaking device, high-pressure liquid nitrogen is first injected into the rock wall through a hollow drill rod, causing the liquid nitrogen to diffuse around the borehole. Under the action of the liquid nitrogen, the rock mass is frozen and cracked, gradually becoming brittle and developing internal fissures. Then, the particles are accelerated to a high speed by a particle acceleration component and then shot through a particle nozzle towards the rock wall around the borehole, causing the rock mass to break under the impact of the particles. Due to the weakening effect of the liquid nitrogen, the rock mass becomes more brittle and develops internal fissures, while the high-speed particles have sufficient impact energy to break the weakened hard rock. This rock-breaking device not only eliminates the problem of wear and tear on traditional mechanical rock-breaking tools but also greatly improves drilling efficiency. Furthermore, this rock-breaking device can achieve waterless operation throughout the entire process, and the liquid nitrogen leaves virtually no residue after vaporization, making the rock-breaking construction process safer and more environmentally friendly.

[0033] Open the gas cylinder valve, start the air compressor to compress the gas and transmit it to the particle acceleration tube. The impact rod moves at high speed along the particle acceleration tube under the action of high-pressure air to impact the particles, causing the particles to be ejected at high speed from the particle nozzle and sprayed onto the rock wall between the four boreholes to break the rock mass. The impact of the particles on the rock wall between the four boreholes allows the liquid nitrogen jets emitted by multiple hollow drill rods to be coupled with the particle impact as much as possible to achieve a better rock breaking effect.

[0034] The vacuum pump can be used to generate negative pressure inside the particle mounting tube to facilitate the reset of the impact rod, and it can also be used to generate negative pressure inside the inner tube to compress the spring of the pad, so as to facilitate the replenishment of particles into the inner tube. Attached Figure Description

[0035] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Wherein:

[0036] Figure 1 A schematic diagram of the structure of a rock-breaking device according to an embodiment of the present invention;

[0037] Figure 2 A schematic diagram of the structure of a hollow drill rod according to an embodiment of the present invention;

[0038] Figure 3 A schematic diagram of the structure of a particle filling device according to an embodiment of the present invention;

[0039] Figure 4 A schematic diagram of a drilling face according to an embodiment of the present invention.

[0040] In the diagram: 1. Self-pressurized liquid nitrogen storage tank; 2. Inner liner; 3. Outer shell; 4. Pressure boosting valve; 5. Safety valve; 6. Vent valve; 7. First solenoid valve; 8. Liquid nitrogen buffer tank; 9. Second solenoid valve; 10. Liquid pump; 11. Transmission box; 12. Motor; 13. Variable frequency control box; 14. Pressure gauge; 15. Third solenoid valve; 16. Drill rig; 17. Hollow drill rod; 18. Drill bit; 19. Packer; 2 0. Liquid nitrogen nozzle; 21. Bridge plug; 22. Gas cylinder; 23. Gas cylinder valve; 24. Air compressor; 25. Ball valve; 26. Pressure gauge; 27. Particle accelerator tube; 28. Impact rod; 29. ​​Fourth solenoid valve; 30. Vacuum pump; 31. Particle chamber; 32. Particle valve; 33. Sleeve; 34. Pad; 35. Spring; 36. Inner tube; 37. Base; 38. Fifth solenoid valve; 39. Particle nozzle. Detailed Implementation

[0041] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0042] In the description of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used merely for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "connected" and "linked" used in this invention should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; they can refer to a direct connection or an indirect connection through intermediate components. Those skilled in the art can understand the specific meaning of these terms according to the specific circumstances.

[0043] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be combined with each other.

[0044] According to specific embodiments created by the present invention, such as Figure 1-4 As shown, the present invention provides a rock-breaking device combining liquid nitrogen jet and particle impact, the rock-breaking device comprising a liquid nitrogen jet fracturing system and a particle impact system;

[0045] The liquid nitrogen jet fracturing system includes at least a liquid supply assembly and a hollow drill pipe 17. The liquid supply assembly is used to supply pressurized liquid nitrogen to the hollow drill pipe 17. The hollow drill pipe 17 is provided with multiple liquid nitrogen nozzles 20 in the circumferential direction. The hollow drill pipe 17 is used to inject liquid nitrogen into the rock mass through the liquid nitrogen nozzles 20 in the borehole on the rock wall.

[0046] The particle impact system includes a particle acceleration component and a particle nozzle 39. The particle acceleration component is used to accelerate particles and spray the particles onto the rock wall near the borehole through the particle nozzle 39.

[0047] In this rock-breaking device, high-pressure liquid nitrogen is first injected into the rock wall through the hollow drill rod 17, causing the liquid nitrogen to diffuse around the borehole. Under the action of the liquid nitrogen, the rock mass is frozen and cracked, gradually becoming brittle and generating internal fissures. Then, the particles are accelerated to a high speed through the particle acceleration component and then shot towards the rock wall around the borehole through the particle nozzle 39, causing the rock mass to break under the impact of the particles. Due to the weakening effect of the liquid nitrogen, the brittleness of the rock mass increases and internal fissures are generated, while the high-speed particles have sufficient impact energy to break the weakened hard rock. This rock-breaking device not only eliminates the problem of wear and tear on traditional mechanical rock-breaking tools, but also greatly improves drilling efficiency. Furthermore, this rock-breaking device can achieve waterless operation throughout the entire process, and there is virtually no residue after the liquid nitrogen vaporizes, making the rock-breaking construction process safer and more environmentally friendly.

[0048] The front end of the hollow drill rod 17 is connected to the drill bit 18. A bridge plug 21 and a packer 19 are spaced apart on the hollow drill rod 17 behind the drill bit 18. The liquid nitrogen nozzle 20 is located on the hollow drill rod 17 between the bridge plug 21 and the packer 19.

[0049] In one embodiment of this application, the hollow drill rod 17 is mounted on the drilling rig 16. The drilling rig 16 drives the drill rod and drill bit 18 to rotate, drilling a hole in the rock wall. After cleaning the hole, the hollow drill rod 17 with a liquid nitrogen nozzle 20 is inserted into the hole. Then, high-pressure liquid nitrogen is supplied to the hollow drill rod 17 through the liquid supply assembly. The bridge plug 21 and the packer 19 can seal the gap between the hollow drill rod 17 and the hole, thereby preventing the liquid nitrogen from escaping from the hole and allowing the liquid nitrogen to seep into the rock mass around the hole, thereby maximizing the weakening range of the rock mass.

[0050] The liquid supply assembly includes at least a self-pressurizing liquid nitrogen storage tank 1 and a liquid nitrogen buffer tank 8, which are connected by a first pipeline. The self-pressurizing liquid nitrogen storage tank 1 is used to fill the hydraulic buffer tank with liquid nitrogen, and a first solenoid valve 7 is provided on the first pipeline. In one embodiment of this application, the first solenoid valve 7 controls the opening and closing of the first pipeline; the self-pressurizing liquid nitrogen storage tank 1 fills the liquid nitrogen buffer tank 8 with liquid nitrogen through the first pipeline, and the liquid nitrogen in the liquid nitrogen buffer tank 8 is pressurized and then transported to the hollow drill pipe 17.

[0051] In this embodiment, a liquid nitrogen buffer tank 8 is installed downstream of the self-pressurized liquid nitrogen storage tank 1. The required amount of liquid nitrogen for each use is first transferred to the liquid nitrogen buffer tank 8. After the liquid nitrogen is released from the liquid nitrogen buffer tank 8 and pressurized, it is input into each hollow drill rod 17. This arrangement can further increase the safety of the rock breaking device during use.

[0052] In this embodiment, the self-pressurized liquid nitrogen storage tank 1 includes an inner liner 2 and an outer shell 3, and is equipped with a pressurization valve 4, a safety valve 5 and a vent valve 6.

[0053] The liquid supply assembly also includes a liquid pump 10, which is located downstream of the buffer tank and is used to pressurize the liquid nitrogen in the liquid nitrogen buffer tank 8 into a liquid nitrogen jet.

[0054] The inlet of the liquid pump 10 is connected to the liquid nitrogen buffer tank 8 via a second pipeline, on which a second solenoid valve 9 is installed.

[0055] In one embodiment of this application, the second pipeline is controlled by the second solenoid valve 9; and the liquid pump 10 is a reciprocating cryogenic liquid pump 10, which pressurizes the liquid nitrogen in the liquid nitrogen buffer tank 8 to turn the liquid nitrogen into a liquid nitrogen jet before inputting it into the hollow drill rod 17 to be shot towards the rock mass, thereby increasing the penetration energy of the liquid nitrogen and its weakening effect on the rock mass.

[0056] The driving source of the liquid pump 10 includes a frequency converter control box 13, a motor 12, and a transmission box 11. The output end of the motor 12 is connected to the input end of the transmission box 11, and the output end of the transmission box 11 is connected to the input shaft of the liquid pump 10. The frequency converter control box 13 is connected to the motor 12 and is used to control the speed of the motor 12. In one embodiment of this application, a transmission box 11 is set between the liquid pump 10 and the motor 12 for transmission, and the transmission box 11 plays the role of deceleration and torque increase. The speed of the motor 12 is controlled by the frequency converter control box 13, thereby realizing the precise adjustment of the working pressure and injection frequency of the reciprocating cryogenic liquid pump 10, and thus realizing the injection of liquid nitrogen into the rock mass according to the required pressure and injection frequency for different rock conditions.

[0057] A third pipeline is connected to the outlet of the liquid pump 10. A third solenoid valve 15 and a pressure gauge 13 are installed on the third pipeline. The third pipeline is connected to multiple hollow drill rods 17 via branch pipes, allowing the liquid pump 10 to simultaneously deliver pressurized liquid nitrogen jets to multiple hollow drill rods 17. In one embodiment of this application, the third solenoid valve 15 controls the opening and closing of the third pipeline, while the pressure gauge 13 measures the pressure of the liquid nitrogen in the third pipeline to determine whether the liquid nitrogen supplied to the hollow drill rods 17 has reached the set pressure. Simultaneously, multiple sets of drilling rigs 16 and drill rods are installed, with each hollow drill rod 17 connected to the third pipeline via a branch pipe. This allows the liquid pump 10 to simultaneously deliver pressurized liquid nitrogen jets to multiple hollow drill rods 17, enabling the multiple hollow drill rods 17 to simultaneously spray liquid nitrogen jets into a larger area of ​​the rock mass, maximizing the area of ​​rock mass weakened by liquid nitrogen and achieving a better weakening effect on the rock mass.

[0058] The particle acceleration assembly includes a particle acceleration tube 27, an impact rod 28, an air compressor 24, and a gas cylinder 22. The impact rod 28 is guided and moved within the particle acceleration tube 27.

[0059] Gas cylinder 22 is connected to air compressor 24 via a pipeline for supplying air to air compressor 24. Gas cylinder valve 22 is installed on the pipeline between gas cylinder 22 and air compressor 24.

[0060] The air compressor 24 is connected to the particle accelerator tube 27 via a pipe and is used to supply compressed gas to the particle accelerator tube 27.

[0061] In one embodiment of this application, the gas cylinder valve 22 is used to control the gas cylinder 22 to supply gas to the air machine. Multiple gas cylinders 22 can be provided, and multiple gas cylinders 22 are connected in parallel on the pipeline connected to the air machine. Each gas cylinder 22 has a gas cylinder valve 22 at its outlet.

[0062] A ball valve 25 and a pressure gauge 26 are installed on the pipeline between the air compressor 24 and the particle acceleration tube 27. The ball valve 25 is used to control the opening and closing of the pipeline, and the pressure gauge 26 is used to monitor whether the gas pressure after the air compressor pressurizes the gas meets the standard. The gas in the gas cylinder 22 is compressed by the air compressor 24 and then input into the particle acceleration tube 27. The high-pressure gas pushes the impact rod 28 to move at high speed in the particle acceleration tube 27, so that the impact rod 28 impacts the particles at high speed, so that the particles gain greater kinetic energy and are ejected from the particle nozzle 39, impacting the rock mass weakened by liquid nitrogen, thereby breaking the rock mass.

[0063] The particle acceleration assembly also includes a particle filling mechanism, which includes at least a sleeve 33 and an inner tube 36. The inner tube 36 is disposed inside the sleeve 33 and is connected to one side of the particle acceleration tube 27 for supplying particles to the particle acceleration tube 27.

[0064] One side of the inner tube 36 is connected to a particle chamber 31 via a pipe, which is used to replenish particles into the inner tube 36.

[0065] In one embodiment of this application, the particles contained in the particle chamber 31 can be particles of materials with high hardness, such as iron particles or steel particles. A particle valve 32 is provided on the pipe between the particle chamber 31 and the inner tube 36. The particle valve 32 is used to control the opening and closing of the pipe so as to control the particle chamber 31 to replenish and deliver particles to the inner tube 36.

[0066] The lower part of the sleeve 33 is provided with a base 37, the inner tube 36 extends into the base 37, the lower part of the inner tube 36 is provided with a bottom plate, the inner tube 36 is guided and sealed with a gasket 34, a spring 35 is provided between the gasket 34 and the bottom plate, and multiple particles are supported above the gasket 34.

[0067] The particle filling mechanism also includes a vacuum pump 30, a fourth pipeline is provided between the vacuum pump 30 and the particle acceleration tube 27, and a fourth solenoid valve 29 is provided on the fourth pipeline to control the reset of the impact rod 28.

[0068] A fifth pipeline is provided between the vacuum pump 30 and the base plate. The fifth pipeline passes through the base plate and extends into the inner tube 36. A fifth solenoid valve 38 is provided on the fifth pipeline for compressing the spring 35.

[0069] In one embodiment of this application, the spring 35 pushes the pad 34, and the pad 34 pushes the particles in the inner tube 36, so that the particles are pushed into the particle acceleration tube 27, so that the impact rod 28 can impact and accelerate the particles.

[0070] The fourth solenoid valve 29 is used to control the opening and closing of the fourth pipeline. When the fourth solenoid valve 29 is opened, the vacuum pump 30 evacuates the particle acceleration tube 27, creating a negative pressure inside the particle acceleration tube 27, thereby resetting the impact rod 28 to its original position for the next impact process.

[0071] The fifth solenoid valve 38 is used to control the opening and closing of the fifth pipeline. When the fifth solenoid valve 38 is opened, the vacuum pump 30 evacuates the inner tube 36 between the pad 34 and the base plate to generate negative pressure, thereby compressing the spring 35 of the pad 34. At this time, the particle valve 32 is opened to replenish the particles in the particle chamber 31 into the inner tube 36.

[0072] This application also provides a rock-breaking method using liquid nitrogen jet combined with particle impact, which employs the aforementioned rock-breaking device and includes the following steps:

[0073] Step 1: First, drill multiple holes in the rock wall, and then insert multiple hollow drill rods 17 connected to the fluid supply assembly into one of the holes.

[0074] Step 2: Open the first solenoid valve 7 to allow the self-pressurized liquid nitrogen storage tank 1 to deliver a set amount of liquid nitrogen to the liquid nitrogen buffer tank 8, and then close the first solenoid valve 7.

[0075] Step 3: Open the second solenoid valve 9 and the third solenoid valve 15, and turn on the liquid pump 10. The liquid pump 10 pressurizes the liquid nitrogen in the liquid nitrogen buffer tank 8 into a liquid nitrogen jet, and then transmits it to the hollow drill rod 17. The liquid nitrogen jet is sprayed into the rock mass through the liquid nitrogen nozzle 20 on the hollow drill rod 17, and the liquid nitrogen is continuously sprayed into the rock mass at a set pressure for a set time.

[0076] Step 4: Open the gas cylinder valve 22, start the air compressor 24 to compress the gas and transmit it to the particle acceleration tube 27. The impact rod 28 moves at high speed along the particle acceleration tube 27 under the action of high-pressure air to impact the particles, causing the particles to be ejected at high speed from the particle nozzle 39 and sprayed onto the rock wall between the four boreholes to break the rock mass. Open the fourth solenoid valve 29 and start the vacuum pump 30 to reset the impact rod 28. Then repeat the above process to make the particles repeatedly impact and break the rock wall. In this embodiment, the particles impact the rock wall between the four boreholes, so that the liquid nitrogen jets emitted by the multiple hollow drill rods 17 are coupled with the particle impact as much as possible to achieve a better rock breaking effect.

[0077] Step 5: When the particles in the inner tube 36 are used up, open the fifth solenoid valve 38 and the particle valve 32, and start the vacuum pump 30 to compress the spring 35 under the pad 34. At this time, the particles in the particle chamber 31 are replenished into the inner tube 36. In this embodiment, the vacuum pump 30 can be used to generate negative pressure in the particle mounting tube to facilitate the reset of the impact rod 28, and can also be used to generate negative pressure in the inner tube 36 to compress the spring 35 under the pad 34, so as to facilitate the replenishment of particles into the inner tube 36.

[0078] Step 6: Repeat steps 1-5 until the set rock excavation task is completed.

[0079] It is understood that the above description is merely exemplary and the embodiments of this application do not limit the scope of the application.

[0080] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention shall be within the scope of protection of the pending claims of the present invention.

Claims

1. A rock-breaking device combining liquid nitrogen jet and particle impact, characterized in that, The rock-breaking device includes a liquid nitrogen jet fracturing system and a particle impact system; The liquid nitrogen jet fracturing system includes at least a liquid supply assembly and a hollow drill pipe. The liquid supply assembly is used to supply pressurized liquid nitrogen to the hollow drill pipe. The hollow drill pipe is provided with multiple liquid nitrogen nozzles in its circumferential direction. The hollow drill pipe is used to inject liquid nitrogen into the rock mass through the liquid nitrogen nozzles in the borehole on the rock wall. The particle impact system includes a particle acceleration component and a particle nozzle. The particle acceleration component accelerates the particles and sprays them onto the rock wall near the borehole through the particle nozzle. A drill bit is connected to the front end of the hollow drill rod. A bridge plug and a packer are spaced apart on the hollow drill rod behind the drill bit. The liquid nitrogen nozzle is located on the hollow drill rod between the bridge plug and the packer. The liquid supply component includes at least a self-pressurizing liquid nitrogen storage tank and a liquid nitrogen buffer tank. The self-pressurizing liquid nitrogen storage tank and the liquid nitrogen buffer tank are connected by a first pipeline. The self-pressurizing liquid nitrogen storage tank is used to fill the hydraulic buffer tank with liquid nitrogen. A first solenoid valve is provided on the first pipeline. The liquid supply component also includes a liquid pump. The liquid pump is located downstream of the buffer tank and is used to pressurize the liquid nitrogen in the liquid nitrogen buffer tank and convert it into a liquid nitrogen jet. The liquid pump inlet is connected to the liquid nitrogen buffer tank via a second pipeline, and a second solenoid valve is installed on the second pipeline. The particle acceleration assembly includes a particle acceleration tube, an impact rod, an air compressor, and a gas cylinder, wherein the impact rod is guided and moved within the particle acceleration tube. The gas cylinder is connected to the air compressor via a pipeline for supplying gas to the air compressor. A gas cylinder valve is installed on the pipeline between the gas cylinder and the air compressor. The air compressor is connected to the particle acceleration tube via a pipeline and is used to supply compressed gas to the particle acceleration tube; The particle acceleration assembly also includes a particle filling mechanism, which includes at least a sleeve and an inner tube. The inner tube is disposed inside the sleeve and is connected to one side of the particle acceleration tube for supplying particles into the particle acceleration tube. One side of the inner tube is connected to a particle chamber via a pipe, and the particle chamber is used to replenish particles into the inner tube. The lower part of the sleeve is provided with a base, the inner tube extends into the base, the lower part of the inner tube is provided with a bottom plate, a guide sealing gasket is provided in the inner tube, a spring is provided between the gasket and the bottom plate, and multiple particles are supported above the gasket. The particle filling mechanism also includes a vacuum pump, and a fourth pipeline is provided between the vacuum pump and the particle acceleration tube. A fourth solenoid valve is provided on the fourth pipeline for controlling the reset of the impact rod. A fifth pipeline is provided between the vacuum pump and the base plate. The fifth pipeline passes through the base plate and extends into the inner tube. A fifth solenoid valve is provided on the fifth pipeline for compressing the spring. The particles in the particle chamber are either iron or steel particles.

2. The rock-breaking device combining liquid nitrogen jet and particle impact according to claim 1, characterized in that, The driving source of the liquid pump includes a frequency converter control box, a motor and a transmission box. The output end of the motor is connected to the input end of the transmission box, and the output end of the transmission box is connected to the input shaft of the liquid pump. The frequency converter control box is connected to the motor and is used to control the speed of the motor.

3. The rock-breaking device combining liquid nitrogen jet and particle impact according to claim 1, characterized in that, A third pipeline is connected to the outlet of the liquid pump, and a third solenoid valve and a pressure gauge are installed on the third pipeline. The third pipeline is connected to multiple hollow drill rods through a branch pipe, so that the liquid pump can simultaneously deliver pressurized liquid nitrogen jets to multiple hollow drill rods.

4. A rock-breaking method using liquid nitrogen jet combined with particle impact, characterized in that, The rock-breaking method uses the liquid nitrogen jet combined with particle impact rock-breaking device as described in claim 3, and the rock-breaking method includes the following steps: Step 1: First, drill multiple holes in the rock wall, and then insert multiple hollow drill rods connected to the fluid supply assembly into one of the holes. Step 2: Open the first solenoid valve to allow the self-pressurized liquid nitrogen storage tank to deliver a set amount of liquid nitrogen to the liquid nitrogen buffer tank, and then close the first solenoid valve. Step 3: Open the second and third solenoid valves and turn on the liquid pump. The liquid pump pressurizes the liquid nitrogen in the liquid nitrogen buffer tank into a liquid nitrogen jet and then transmits it to the hollow drill rod. The liquid nitrogen jet is sprayed into the rock mass through the liquid nitrogen nozzle on the hollow drill rod and continuously sprays liquid nitrogen into the rock mass at a set pressure for a set time. Step 4: Open the gas cylinder valve, start the air compressor to compress the gas and transmit it to the particle acceleration tube. The impact rod moves at high speed along the particle acceleration tube under the action of high-pressure air to impact the particles, causing the particles to be ejected at high speed from the particle nozzle and sprayed onto the rock wall between the four boreholes to break the rock mass; open the fourth solenoid valve and start the vacuum pump to reset the impact rod; then repeat the above process to make the particles repeatedly impact and break the rock wall. Step 5: When the particles in the inner tube are used up, open the fifth solenoid valve and the particle valve, and start the vacuum pump to press down the spring on the pad. At this time, the particles in the particle chamber are replenished into the inner tube. Step 6: Repeat steps 1-5 until the set rock excavation task is completed.

Images