Manufacturing and assembling process of tunneling liquid oxygen rock breaking cracker

Abstract

The invention provides a manufacturing and assembling process of a tunneling liquid oxygen rock breaking fracturing device, the fracturing device, an exhaust pipe, a liquid injection pipe, an electric ignition head, an ignition wire and a manufacturing tool are included, the assembled fracturing device is safe, reliable and extremely high in operability, drilling is completed on a tunneling section according to design, and the fracturing efficiency is greatly improved. The assembled fracturing device is pushed to a certain position of a blast hole and blocked, and oxygen injection detonation can be completed according to a program; the liquid oxygen rock breaking fracturing device is good in rock breaking effect when being used for tunneling, simple, easy to use, reliable, efficient, economical, applicable and capable of being used in various scenes. Compared with traditional explosive blasting, liquid oxygen rock breaking is small in harmful effect influence range, few in toxic and harmful products, higher in efficiency and lower in cost, and is a novel green, environment-friendly, efficient and safe tunneling construction technology.

Description

Technical Field

[0001] The present invention relates to the technical field of rock-breaking explosion, and particularly to a manufacturing and assembly process of a liquid oxygen rock-breaking cracker for tunnel excavation. Background Art

[0002] With the wide application of engineering technology, tunnels are a form of people's utilization of underground space and are widely used in the fields of railways, highways, water conservancy, hydropower, mines, municipal administration, civil air defense, etc., playing an increasingly important role in national economic construction and national defense engineering construction. Common excavation methods include the drill-and-blast method, the shield method, and the tunneling method. The drill-and-blast method is widely adopted because of its strong adaptability to geological conditions and low excavation cost. In recent years, with the rapid development of the national economic construction and the continuous enhancement of social environmental protection awareness, there are more and more areas where the use of ordinary explosive blasting is restricted or even not allowed, causing great difficulties to tunnel excavation construction. As a result, those tunnel excavation projects restricted by explosive blasting have to adopt processes such as mechanical hydraulics, which brings the consequences of low efficiency, high cost, and poor environmental protection, causing great difficulties in the construction period control of tunnel excavation projects and affecting the effective exertion of the economic and social benefits of the projects.

[0003] At present in China, there is no set of safe, efficient, simple-structured, and economically applicable liquid oxygen rock-breaking equipment for tunnel excavation construction, and there is even no liquid oxygen rock-breaking technology and process suitable for safe, environmental protection, and high efficiency in tunnel excavation. Summary of the Invention

[0004] The present invention provides a manufacturing and assembly process of a liquid oxygen rock-breaking cracker for tunnel excavation. The liquid oxygen rock-breaking cracker is used, and the cracker is located in the blast holes of the tunnel excavation section. Through the welding manufacturing process and assembly method of the cracker made of thermoplastic materials such as polyethylene and nylon 12, after being tested under multiple tunnel excavation liquid oxygen rock-breaking scenario conditions, the gas explosion operation efficiency is high, the operability is extremely strong, the assembled cracker is safe and reliable, and the gas explosion effect is good.

[0005] To solve the above problems, the present invention provides a manufacturing and assembly process of a liquid oxygen rock-breaking cracker for tunnel excavation, including a cracker, an exhaust pipe, a liquid injection pipe, an electric igniter, an ignition wire, and manufacturing tools;

[0006] The manufacturing and assembly process of the liquid oxygen rock-breaking cracker for tunnel excavation is specifically as follows:

[0007] S01. Prepare the manufacturing tools for cracker assembly. The manufacturing tools include a pipe body welding machine, an insertion welding machine for pipe caps and exhaust pipes, a hand drill, a beveller, and a through-hole sizing rod;

[0008] S02. Manufacture a biomass fuel core, and the steps are as follows:

[0009] 1) Use a hand drill to drill a row of liquid injection holes (with a hole diameter of about 3 - 5 mm) at intervals of about 20 - 40 cm along the length section of the liquid injection pipe that is expected to be placed inside the fracturing device body.

[0010] 2) String combustible biomass cores (or rolls of paper) together with the liquid injection pipe, with the length being adapted to the length of the fracturing device body.

[0011] S03. The assembly of the electric ignition device is as follows:

[0012] 5) Place the electric ignition heads at the 1 / 5 and 4 / 5 positions at the lower end of the pipe string respectively.

[0013] 6) The electric ignition heads should be in close contact with the combustible cores.

[0014] 7) The leg wires of the electric ignition heads are connected in parallel and then connected in series with the electric ignition wire.

[0015] 8) Wrap the wiring joints with insulating tape and fix them to the cores with tape.

[0016] S04. Drill holes in the pipe cap: Use a hand drill to drill three round holes with different diameters on the top cover of a pipe cap. One round hole has a diameter of 3 - 4 mm for placing the ignition wire; one round hole has a diameter of 13 - 14 mm for placing the sleeve; and the other round hole is for placing the exhaust pipe, with a diameter slightly smaller than the outer diameter of the exhaust pipe.

[0017] S05. Process the pipe cap: Use a plug - in welding machine to insert and weld a sleeve and an exhaust pipe of a certain length from the outside of the pipe cap to the round holes with corresponding diameters. At the same time, insert a through - hole shaping rod from the exhaust pipe opening inside the pipe cap into the welding part and keep it in position, and then cool and form.

[0018] S06. Assemble the pipe body: Heat and melt the pipe cap and a pipe body of a certain length with an electric heating plate. After taking out the heating plate, immediately butt - joint the pipe cap and the pipe body, and continuously apply a certain pressure to press and weld the pipe body and the pipe cap tightly, and then cool and form.

[0019] S07. Thread the pipe and install the core: Use two wire threading devices to thread the liquid injection pipe and the ignition wire in the processed biomass string from inside the fracturing device body to the outside, respectively passing through the sleeve of the pipe cap and the small round hole. By applying force synergistically through pushing and pulling, slowly load the entire biomass string into the fracturing device body. Then, use sealant to seal and fix the joints between the sleeve and the liquid injection pipe, and between the small round hole and the ignition wire to form a semi - finished fracturing device. Then, use an ohmmeter to detect the integrity of the electric ignition device.

[0020] S08. Seal the pipe body: Heat and melt the semi - finished fracturing device and another pipe cap with an electric heating plate. After taking out the heating plate, butt - joint them and continuously apply a certain pressure to press and weld the semi - finished fracturing device and the pipe cap tightly, and then cool and form to form a closed finished fracturing device.

[0021] S09. Edge planing and forming: Use an edge planer to plane the flanging convex ring of the weld on the outside of the fracturer tube body;

[0022] S10. Sealing the tube ends: Use waterproof tape or the like to do a good job of waterproof sealing at the ends of the liquid injection tube and the exhaust pipe to prevent water, mud and other sundries from entering the tube during operation and affecting the normal function of the fracturer;

[0023] S11. Binding the coils of the liquid injection tube and the exhaust pipe: To facilitate handling and on-site operation and prevent the pipeline from being damaged, the coils of the liquid injection tube and the exhaust pipe should be bound into shape with tape;

[0024] S12. Marking numbers: After each set of liquid oxygen rock fracturing unit is completed, mark numbers at the positions of the fracturer tube body and the end of the liquid injection tube respectively. The marking should include at least information such as the length of the fracturer, the hole position, the detonation section number, etc.;

[0025] S13. After the ignition device is set and after the fracturer assembly is completed, use a special instrument to check the integrity of the circuit and the resistance value, and compare with the design. If any problems are found, deal with them in time;

[0026] S14. Then drill holes on the tunnel excavation section according to the design, push the assembled fracturer into the blast hole to a certain position according to the design and block it;

[0027] S15. After the warning is in place and the liquid oxygen is filled, power on and detonate. Instantly excited by the heat source of the igniter head, the combustible substances near the igniter head in the blast hole fracturer are quickly ignited, and the combustion range expands instantly. The liquid oxygen that has not participated in the combustion is heated from liquid to gas, and a relatively high temperature and a relatively large quasi-static pressure can be formed in the blast hole instantly, causing the rock to crack and move, thus completing the liquid oxygen rock fracturing for tunnel excavation.

[0028] A further solution is that the preparation steps for welding and assembling the fracturer tube body are as follows:

[0029] 1) Prepare the fracturer pipe material: According to the design scheme of the liquid oxygen rock fracturing project, prepare round pipe materials of corresponding specifications and models and a certain size. The outer diameter of the liquid oxygen rock fracturing tube for tunnel excavation is preferably 40 - 70 mm;

[0030] 2) Prepare pipe caps with the same material and outer diameter as the fracturer pipe material and with a wall thickness not less than that of the pipe material. Two pipe caps are required to assemble a set of fracturers;

[0031] 3) Prepare the tools and equipment for assembly. Prepare a tube body welding machine, an insertion welding machine for pipe caps and exhaust pipes, a hand drill, an edge planer and a through-hole shaping rod;

[0032] 4) preparing the injection tube, exhaust pipe, biomass core, electric ignition head, electric ignition wire, and sleeve, wherein the length of the injection tube, exhaust pipe, and ignition wire is determined according to the design, the number of ignition heads is usually 1 to 2 per fracturing device, and the sleeve is preferably 10 cm long;

[0033] 5) Prepare ohmmeter and other testing instruments.

[0034] A further solution is that the fracturing device welding method is as follows:

[0035] 1) The welding of the pipe body and the pipe cap of the fracturing device should be aligned and smooth without misalignment. The weld cutting should be smooth, and the outer diameter of the weld should not be larger than the pipe diameter of the fracturing device.

[0036] 2) At the joints between the casing, exhaust pipe and pipe cap, there should be no blockage inside the pipe and the inner diameter should not be reduced;

[0037] 3) The joints between the injection tube and the sleeve, the ignition wire and the small round hole of the tube cap should be firmly glued and waterproof, and the wire and injection tube should not be damaged during operation;

[0038] 4) During planing and welding operations, workers should wear gloves and pay attention to electrical safety to avoid burns and planing injuries.

[0039] A further solution is that one end of the pipe opening of the exhaust pipe is seamlessly plugged into the pipe cap of the fracturing device by hot melting.

[0040] A further solution is that the injection tube is connected to the injection main tube after passing through the closure.

[0041] A further solution is that the foot wires of the electric ignition head are connected in parallel and then in series with the ignition wire, the connection points are wrapped with insulating tape and fixed to the biomass fuel core with tape.

[0042] A further solution is that it includes a fracturing device, a liquid injection pipe, an exhaust pipe, an electric ignition device and a biomass fuel core. The fracturing device is located inside a blasthole in a tunnel excavation section. The biofuel core is installed in the fracturing device. The fracturing device is provided with two pipe caps. The electric ignition device is provided with an electric ignition head and an electric ignition wire. The exhaust pipe is seamlessly connected to the pipe cap of the fracturing device. The fracturing device is made of thermoplastic material, has low temperature resistance, good waterproof sealing and high strength.

[0043] A further solution is that both the injection pipe and the exhaust pipe are round tubes made of high-molecular polyethylene, high-density polyethylene or nylon 12 material with good thermal insulation, and can be hot-melt processed, and have low-temperature resistance, good waterproof sealing and high strength.

[0044] A further solution is that the biomass fuel core includes liquid oxygen explosion paper, or is made of renewable biomass combustible raw materials such as straw powder, wood powder, and carbon powder.

[0045] A further solution is that the thickness of the top structure of the pipe cap of the cracker is 5 - 7 mm, and the thickness of the pipe body of the cracker is 1.5 - 3.0 mm.

[0046] The beneficial effects of the present invention are as follows: The tunnel boring liquid oxygen rock-breaking cracker of the present invention adopts a structure including a cracker, a liquid injection pipe, an exhaust pipe, an electric ignition device, and a biomass fuel core. The cracker made of thermoplastic materials such as liquid oxygen explosion polyethylene and nylon 12 has a simple and environmentally friendly structure, and the welding and assembly process method has the following advantages:

[0047] 1. The present invention is convenient for on-site flexible processing and assembly of various tunnel boring liquid oxygen rock-breaking crackers according to the actual engineering situation. Moreover, the exhaust pipe is hot-melt welded, with firm welding, good waterproof airtightness, and good explosion effect.

[0048] 2. The present invention uses thermoplastic materials as the main materials of the cracker, which is convenient for on-site flexible processing and assembly of various crackers according to the actual engineering situation. Moreover, the hot-melt welding process equipment is relatively simple, with firm welding, good airtightness, and good cracker forming.

[0049] 3. The present invention uses thermoplastic materials as the main materials of the cracker, which not only has good low-temperature performance and high strength, but also has heat insulation and insulation. On the premise of ensuring the safety of liquid oxygen explosion operation, it reduces the heat exchange between liquid oxygen and media such as rocks, reduces the loss of liquid oxygen vaporization during the liquid oxygen operation process, and improves the utilization rate of liquid oxygen.

[0050] 4. The present invention uses materials such as high-density, high-molecular polyethylene, and nylon 12 as the main materials of the cracker, all of which are common materials, with wide sources, safety and reliability, low cost, and are convenient for large-scale liquid oxygen explosion engineering applications.

[0051] 5. The present invention follows the concept of green environmental protection from materials to processing, from cracker processing to the whole process after detonation. After liquid oxygen breaks the rock, only oxygen, carbon dioxide, and water are generated, and basically no other toxic and harmful substances are generated, greatly reducing the occurrence of tunnel boring blasting fume poisoning.

[0052] 6. The coiling and binding of the exhaust pipe coil and the marking of numbers are convenient for handling and on-site operations.

[0053] 7. Compared with traditional explosive blasting, the liquid oxygen rock-breaking of the present invention has a low blasting vibration intensity, only equivalent to one-tenth of traditional explosive blasting, and has a small influence range on the tunnel surrounding rock and adjacent buildings (structures); the liquid oxygen combustion explosion speed is much lower than the explosive detonation speed, and the brisance is low. While breaking the rock, it produces less excessive pulverization of the rock, and the amount of dust generated during the rock-breaking process is small, which is more green and environmentally friendly and is beneficial to tunnel boring construction engineering applications.

[0054] The processing, assembly and process method of the liquid oxygen rock-breaking cracker for tunnel boring in the present invention have been verified by rock-breaking tests for tunnel boring at different altitudes and under different environmental conditions. The cracker has high assembly operation efficiency, extremely strong operability, the assembled cracker is safe and reliable, has good rock-breaking effect, is simple to use, reliable and efficient, economical and applicable, and can be used in a variety of scenarios. Compared with traditional explosive blasting, liquid oxygen rock-breaking has a smaller range of harmful effects, fewer toxic and harmful products, higher efficiency and lower cost, and is a new construction technology for tunnel boring that is green, environmentally friendly, efficient and safe. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a schematic diagram of the assembly and manufacturing process of the embodiment of the present invention;

[0056] Figure 2 It is a schematic diagram of the assembly structure of the embodiment of the present invention;

[0057] Figure 3 It is a schematic diagram of the disassembled structure of the embodiment of the present invention.

[0058] REFERENCE SIGNS

[0059] 1. Cracker tube body; 2. Lower tube cap; 3. Upper tube cap; 4. Sleeve; 5. Liquid injection tube; 6. Exhaust pipe; 7. Ignition wire; 8. Electric ignition head; 9. Large round hole. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0060] In order to more fully understand the technical content of the present invention, the technical solution of the present invention will be further introduced and described below in conjunction with the drawings and specific embodiments, but it is not limited thereto.

[0061] As Figures 1 to 3 shown, in the specific embodiment of the present invention, the manufacturing and assembly process of a liquid oxygen rock-breaking cracker for tunnel boring in the present invention includes a cracker, an exhaust pipe 6, a liquid injection tube 5, an electric ignition head 8, an ignition wire 7 and manufacturing tools;

[0062] The manufacturing and assembly process of the liquid oxygen rock-breaking cracker for tunnel boring is as follows in specific method steps:

[0063] S01. Prepare the manufacturing tools for cracker assembly. The manufacturing tools include a tube body welding machine, tube caps including a lower tube cap 2 and an upper tube cap 3, an insertion welding machine for the exhaust pipe 6, a hand drill, an edge planer and a through-hole shaping rod;

[0064] S02. Manufacture the biomass fuel core body, and the steps are as follows:

[0065] 1) Use a hand drill to drill a row of liquid injection holes (hole diameter about 3 - 5 mm) at intervals of about 20 - 40 cm in the length section of the liquid injection tube 5 expected to be placed in the cracker tube body 1;

[0066] 2) Connect the combustible biomass cores (or roll papers) in series with the liquid injection tube 5, and the length shall be adapted to the length of the fracturing device tube body 1;

[0067] S03. The assembly of the electric ignition device is as follows:

[0068] 9) Place the electric ignition heads 8 at the 1 / 5 and 4 / 5 positions at the lower end of the tube string respectively;

[0069] 10) The electric ignition heads 8 should be in close contact with the combustible cores;

[0070] 11) The lead wires of the electric ignition heads 8 are connected in parallel and then connected in series with the electric ignition wire 7;

[0071] 12) Wrap the wiring joints with insulating tape and fix them to the cores with tape;

[0072] S04. Drill holes in the pipe cap: Drill three round holes with different diameters on the top cover of an upper pipe cap 3. One round hole has a diameter of 3 - 4 mm for placing the ignition guide; one large round hole 9 has a diameter of 13 - 14 mm for placing the sleeve 4; the other round hole is for placing the exhaust pipe 6, and its diameter is slightly smaller than the outer diameter of the exhaust pipe 6;

[0073] S05. Process the pipe cap: Use a plug-in welding machine to insert and weld a section of the sleeve 4 and the exhaust pipe 6 from the outside of the pipe cap into the round holes with corresponding diameters. At the same time, insert a through-hole shaping rod from the exhaust pipe 6 opening inside the pipe cap into the welding part and keep it positioned, and cool and form; the function of this sleeve 4 is that the liquid injection tube 5 runs through the sleeve 4. This exhaust pipe 6 mainly plays the role of exhausting gas in this fracturing device, and mainly plays the role of the liquid injection tube 5 when connected to the next fracturing device;

[0074] S06. Assemble the tube body: Heat and melt the processed pipe cap and a certain length of the tube body with an electric heating plate. Immediately after taking out the heating plate, butt-join the pipe cap and the tube body, and continuously apply a certain pressure to press and weld the tube body and the pipe cap, and cool and form;

[0075] S07. Thread the tube and install the core: Use two wire threading devices to thread the liquid injection tube 5 and the ignition wire 7 in the processed biomass string from inside the fracturing device tube body 1 to the outside, and respectively pass through the sleeve 4 of the pipe cap and the small round hole. By applying force synergistically by pushing and pulling, slowly load the entire biomass string into the fracturing device tube body 1, and then use sealant to seal and fix the joints between the sleeve 4 and the liquid injection tube 5, and the small round hole and the ignition wire 7 to form a semi-finished fracturing device. This liquid injection tube 5 is connected to the liquid injection main pipe or the exhaust pipe 6 in the previous fracturing device, mainly playing the role of injecting liquid. When loading the biomass string, do not force it in. It is not easy to change the shape and density of the biomass string, and the electric ignition device shall not be damaged. Then use an ohmmeter to detect the integrity of the electric ignition device;

[0076] S08. Closed Tube Body: Heat the semi-finished fracturer and another pipe cap with an electric heating plate until they are melted, then remove the heating plate, butt-join them and continuously apply a certain pressure to tightly weld and compress the semi-finished fracturer and the pipe cap, and cool and form them to obtain a finished closed fracturer;

[0077] S09. Edge Planing and Forming: Use an edge planer to plane the weld bead flanging ring on the outside of the fracturer tube body 1;

[0078] S10. Sealing the Tube Ends: Use waterproof tape, etc. to do a good job in waterproof sealing of the ends of the liquid injection pipe 5 and the exhaust pipe 6 to prevent water, mud and other sundries from entering the pipe during operation and affecting the normal function of the fracturer;

[0079] S11. Coiling and Binding of the Liquid Injection Pipe 5 and the Exhaust Pipe 6: For the convenience of handling and on-site operation and to prevent the pipeline from being damaged, the liquid injection pipe 5 and the exhaust pipe 6 should be coiled and bound with tape;

[0080] S12. Marking Numbers: After each set of liquid oxygen rock fracturing device assemblies is completed, mark numbers at the end positions of the fracturer tube body 1 and the liquid injection pipe 5 respectively, and the marking should at least include information such as the length of the fracturer, the hole position, the initiation section number, etc.;

[0081] S13. After the ignition device is set and after the fracturer assembly is completed, a special instrument should be used to check the integrity of the circuit and the resistance value, and compare it with the design. If any problems are found, they should be dealt with in a timely manner;

[0082] S14. Then, drill holes according to the design on the tunnel face, push the assembled fracturer into the blast hole to a certain position and block it;

[0083] S15. After the warning is in place and the liquid oxygen is filled, power on and initiate. Instantly excited by the heat source of the igniter head, the combustible substances near the igniter head in the blast hole fracturer are quickly ignited, the combustion range rapidly expands, and at the same time, the surrounding liquid oxygen quickly vaporizes when heated, and the volume expands sharply. Instantly, a relatively large quasi-static pressure can be formed in the blast hole, causing the rock to crack and move, thus completing the liquid oxygen rock fracturing for tunnel excavation.

[0084] Furthermore, the preparation steps for the welding and assembly of the fracturer tube body 1 are as follows:

[0085] 1) Prepare the fracturer pipe material: According to the design scheme of the liquid oxygen rock fracturing project, prepare round pipe materials with corresponding specifications, models and certain dimensions. The outer diameter of the fracturer tube body 1 for tunnel excavation by liquid oxygen rock fracturing is preferably 40 - 70 mm;

[0086] 2) Prepare pipe caps with the same material and outer diameter as the fracturer pipe material and with a wall thickness not less than that of the pipe material. Two pipe caps are required for assembling a set of fracturers;

[0087] 3) Prepare tools and equipment for assembly. Prepare the pipe body welding machine, the plug welding machine for the pipe cap and the exhaust pipe 6, the hand drill, the edge planer and the through-hole shaping rod;

[0088] 4) Prepare the injection tube 5, exhaust tube 6, biomass core, electric ignition head 8, electric ignition wire 7, and sleeve 4. The lengths of the injection tube 5, exhaust tube 6, and ignition wire 7 are determined according to the design. The number of ignition heads is usually 1 to 2 per fracturing device. The sleeve 4 preferably has a length of 10 cm.

[0089] 5) Prepare ohmmeter and other testing instruments.

[0090] Further, the fracturing device welding method is as follows:

[0091] 1) The welding of the pipe body 1 of the fracturing device should be aligned and smooth, without misalignment, the weld cutting should be smooth, and the outer diameter of the weld circumference should not be larger than the diameter of the fracturing device;

[0092] 2) At the joints between the sleeve 4, the exhaust pipe 6 and the pipe cap, there should be no blockage inside the pipe and the inner diameter should not be reduced;

[0093] 3) The joints between the injection tube 5 and the sleeve 4, the ignition wire 7 and the small round hole of the tube cap should be firmly glued and waterproof and sealed. The wire and the injection tube 5 should not be damaged during operation;

[0094] 4) During planing and welding operations, workers should wear gloves and pay attention to electrical safety to avoid burns and planing injuries.

[0095] Furthermore, one end of the pipe opening of the exhaust pipe 6 is seamlessly plugged into the pipe cap of the cracking device by hot melting.

[0096] Furthermore, after the injection tube 5 passes through the closure, it is connected to the injection mother tube.

[0097] Furthermore, after the foot wires of the electric ignition head 8 are connected in parallel, they are then connected in series with the ignition wire 7, and the connection points are wrapped with insulating tape and fixed to the biomass fuel core with tape.

[0098] Furthermore, the invention comprises a fracturing device, a liquid injection pipe 5, an exhaust pipe 6, an electric ignition device and a biomass fuel core. The fracturing device is located in a blasthole of a tunnel excavation section, a biofuel core is installed in the fracturing device, the fracturing device is provided with two or more pipe caps 3, the electric ignition device is provided with an electric ignition head 8 and an electric ignition wire 7, the exhaust pipe 6 is seamlessly connected to the pipe cap of the fracturing device, and the fracturing device is made of thermoplastic material and has waterproof sealing properties.

[0099] Furthermore, the injection pipe 5 and the exhaust pipe 6 are both round tubes made of high molecular weight polyethylene, high density polyethylene or nylon 12 material, which have good heat insulation and can be hot-melt processed.

[0100] Furthermore, the biomass fuel core includes liquid oxygen explosion paper, or is made of renewable combustible biomass raw materials such as straw powder, wood powder, and carbon powder.

[0101] Furthermore, the thickness of the top structure of the cap of the injection tube 5 is 5-7 mm, and the thickness of the fracturing device tube body 1 is 1.5-3.0 mm.

[0102] The basic requirements of the tunnel boring liquid oxygen rock breaking device in the embodiment of the present invention are as follows:

[0103] 1) Good low temperature performance. The material must not crack or deform in a low temperature environment of -183°C and must have a certain strength. Raw materials such as high molecular weight polyethylene, high density polyethylene, and nylon 12 are preferred, and other materials are not easily added.

[0104] 2) Thermal insulation and environmental protection. The fracturing device is required to have a low thermal conductivity and good thermal insulation, so as to minimize the heat exchange between liquid oxygen and surrounding rock mass and other media during liquid oxygen rock breaking operations in tunnel excavation, and reduce the heat absorption and vaporization loss of low-temperature liquid oxygen.

[0105] 3) The material can be processed by thermoplastics, which is convenient for on-site processing and assembly. After the fracturing device is assembled, it has good air tightness and waterproof seal without cracking.

[0106] 4) The material source is wide, which is conducive to factory production, low cost and engineering application.

[0107] 5) Under the premise of ensuring the strength of the fracturer and facilitating welding, the structural thickness of the fracturer tube body 1 is minimized as much as possible. Under the premise of a certain blasthole diameter, the effective volume of the fracturer is increased to reduce the useless work used to overcome the constraints of the fracturer tube body 1 during liquid oxygen rock breaking, and improve the rock breaking efficiency. After multiple verifications, the thickness of the tube body 1 of the tunnel excavation liquid oxygen rock breaking fracturer is preferably 1.5-3.0 mm, and the thickness of the top structure of the tube cap is preferably 5-7 mm.

[0108] The present invention relates to the technical field of liquid oxygen rock breaking, which introduces the mature open-pit liquid oxygen rock breaking technology into the construction of underground tunnel excavation projects. Liquid oxygen rock breaking is applied in areas where traditional explosive blasting cannot be used, to replace the inefficient mechanical hydraulic crushing. During liquid oxygen rock breaking (or air energy expansion cracking), a special liquid oxygen rock breaking dedicated roll paper, or a biomass fuel core made of combustible material raw materials such as straw powder, wood powder, carbon powder, etc. in a certain proportion, is loaded into the cracker. At the same time, the cracker is also equipped with a liquid injection pipe 5, an exhaust pipe 6, and an electric ignition device. Then, according to the design, drilling is completed on the tunnel excavation section, and the assembled cracker is pushed into the blast hole to a certain position according to the design and blocked. After the warning is in place and liquid oxygen is filled, it is detonated by power on. Instantly excited by the heat source of the igniter head, the combustible material near the igniter head in the blast hole cracker is quickly ignited, and the combustion range rapidly expands. At the same time, the surrounding liquid oxygen quickly vaporizes when heated, and the volume expands sharply. A large quasi-static pressure can be formed in the blast hole instantly, causing the rock to crack and move, and completing the liquid oxygen rock breaking for tunnel excavation.

[0109] The beneficial effects of the present invention are as follows: The liquid oxygen rock breaking cracker for tunnel excavation of the present invention adopts a cracker structure including a cracker, a liquid injection pipe 5, an exhaust pipe 6, an electric ignition device, and a biomass fuel core. The cracker made of thermoplastic materials such as liquid oxygen air explosion polyethylene and nylon 12 has a simple and environmentally friendly structure, and the welding and assembly process method has the following advantages:

[0110] 1. The present invention is convenient for on-site flexible processing and assembly of various liquid oxygen rock breaking crackers for tunnel excavation according to the actual situation of the project. Moreover, the exhaust pipe 6 is hot melt welded, with firm welding, good waterproof airtightness, and good air explosion effect.

[0111] 2. The present invention uses hot melt materials as the main materials of the cracker, which is convenient for on-site flexible processing and assembly of various crackers according to the actual situation of the project. Moreover, the hot melt welding process equipment is relatively simple, with firm welding, good airtightness, and good cracker forming.

[0112] 3. The present invention uses hot melt materials as the main materials of the cracker, which not only has good low-temperature performance and high strength, but also has heat insulation and insulation. On the premise of ensuring the safety of liquid oxygen air explosion operation, it reduces the heat exchange between liquid oxygen and media such as rocks, reduces the loss of liquid oxygen vaporization during the liquid oxygen operation process, and improves the utilization rate of liquid oxygen.

[0113] 4. The present invention uses materials such as high-density, high-molecular polyethylene, and nylon 12 as the main materials of the cracker. All of them are common materials, with wide sources, safety and reliability, and low cost. It is convenient for large-scale liquid oxygen air explosion project applications.

[0114] 5. The present invention follows the concept of green environmental protection from materials to processing, from rock breaking operation to the whole process after detonation. After liquid oxygen rock breaking, only oxygen, carbon dioxide, and water are generated, and basically no other toxic and harmful substances are generated, greatly reducing the occurrence of poisoning caused by blasting fumes in tunnel excavation blasting;

[0115] 6. The coiling and labeling of the exhaust pipe 6 make it convenient for handling and on-site operations.

[0116] 7. Compared with traditional explosive blasting, the blasting vibration intensity of this liquid oxygen rock breaking is low, only equivalent to one-tenth of that of traditional explosive blasting, and the influence range on the tunnel surrounding rock and adjacent buildings (structures) is small; the combustion explosion speed of liquid oxygen is much lower than the explosive detonation speed, and the brisance is low. While breaking the rock, there is less excessive pulverization of the rock, and the amount of dust generated during the rock breaking process is small, which is more environmentally friendly and conducive to the engineering application of tunnel excavation construction.

[0117] The processing, assembly and process method of the liquid oxygen rock breaking cracker for tunnel excavation of the present invention have been verified by liquid oxygen rock breaking tests for tunnel excavation under different altitudes and different environmental conditions. The cracker processing operation has high efficiency, extremely strong operability, the assembled cracker is safe and reliable, has good rock breaking effect, is simple to use, reliable, efficient, economical and applicable, and can adapt to various scenarios. The assembly process method of the liquid oxygen rock breaking cracker for tunnel excavation, compared with traditional explosive blasting, has a small influence range of harmful effects and less toxic and harmful products generated by blasting. Compared with the mechanical hydraulic process, the liquid oxygen rock breaking has higher efficiency and lower cost, and is a truly green, environmentally friendly, efficient and safe tunnel excavation construction technology.

[0118] The above are only the preferred embodiments of this patent, and do not limit the scope of this patent. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings, directly or indirectly applied in other related technical fields, shall fall within the protection scope of this patent.

Claims

1. A manufacturing and assembly process for a liquid oxygen rock-breaking device for tunneling, characterized in that: It includes a cracker, an exhaust pipe, a liquid injection pipe, an electric ignition head, an ignition wire and a manufacturing tool; The manufacturing and assembly process of the tunnel boring liquid oxygen rock breaking device has the following specific steps: S01, preparing production tools for assembling the fracturing device, the production tools comprising a pipe body welding machine, a plug welding machine for pipe caps and exhaust pipes, a hand drill, an edge planer and a through-hole shaping rod; S02, making a biomass fuel core, the steps are as follows: 1) Use a hand drill to drill a row of injection holes (aperture of about 3 to 5 mm) at intervals of about 20 to 40 cm in the length section of the injection tube that is expected to be placed inside the fracturing device body; 2) Connect the combustible biomass cores (or paper rolls) in series with a liquid injection tube, the length of which matches the length of the cracker tube; S03. Install the electric ignition device as follows: 1) Place the electric ignition heads at the 1 / 5 and 4 / 5 positions at the lower end of the pipe string respectively; 2) The electric ignition head should be in close contact with the combustible core; 3) The electric ignition head foot wires are connected in parallel and then in series with the electric ignition wires; 4) Wrap the wiring with insulating tape and fix it to the core with tape; S04. Drilling holes in pipe caps: Use an electric drill to drill three holes of different diameters on the top cover of a pipe cap. One hole has a diameter of 3-4 mm and is used to place the ignition wire; one hole has a diameter of 13-14 mm and is used to place the sleeve; the other hole is used to place the exhaust pipe, and its diameter is slightly smaller than the outer diameter of the exhaust pipe; S05. Processing pipe caps: Use a plug-in welding machine to plug and weld a certain length of sleeve and exhaust pipe from the outside of the pipe cap to the corresponding diameter circular hole. At the same time, use a through-hole shaping rod to insert the exhaust pipe opening inside the pipe cap into the welding position and keep it in position, and cool it to form; S06. Assemble the pipe body: Heat and melt the pipe cap and the pipe body of a certain length with an electric heating plate. After removing the heating plate, immediately butt the pipe cap with the pipe body and continue to apply a certain pressure to press and weld the pipe body and the pipe cap, and cool to form; S07, pipe threading and core loading: use two threading tools to push the injection pipe and ignition wire in the processed biomass string from the inside of the cracker tube to the outside, respectively through the pipe cap sleeve and the small round hole, and slowly load the entire biomass string into the cracker tube by pushing and pulling the front and back forces, and then use sealant to seal and fix the joints between the sleeve and the injection pipe, the small round hole and the ignition wire to form a semi-finished cracker, and then use an ohmmeter to detect the integrity of the electric ignition device; S08, closing the pipe body: heating and melting the semi-finished product of the fracturing device and another pipe cap by an electric heating plate, removing the heating plate, butting and continuously applying a certain pressure, pressing and welding the semi-finished product of the fracturing device and the pipe cap, cooling and forming, and forming a closed fracturing device finished product; S09, planing and forming: using a planer to plan the weld flange convex ring outside the fracturing device tube body; S10. Seal the pipe end: Use waterproof tape to make the ends of the injection pipe and exhaust pipe waterproof and seal to prevent water, mud and other debris from entering the pipe during operation and affecting the normal function of the fracturing device; S11. Binding of injection pipe and exhaust pipe coil: To facilitate transportation and on-site operation and prevent pipeline damage, the injection pipe and exhaust pipe coil should be bound with tape; S12. Marking numbers: After each set of liquid oxygen rock breaking fracturing device assembly is completed, numbers are marked on the fracturing device tube body and the end of the injection tube, and the markings contain at least information such as the length of the fracturing device, the hole position, and the detonation section number; S13. After the ignition device is set up and the cracker assembly is completed, special instruments should be used to check the circuit integrity and resistance value, and compare them with the design. If any problems are found, they should be dealt with in time; S14, then drilling is completed on the tunnel entry section according to the design, and the assembled fracturing device is pushed into a certain position of the blasthole according to the design and blocked; S15. After the alarm is in place and liquid oxygen is injected, power is turned on to detonate. The ignition head in the borehole fracturing device is instantly stimulated by the heat source of the ignition head, and the combustible material near the ignition head is quickly ignited, which instantly forms a large quasi-static pressure in the borehole, causing the rock to crack and move, thereby completing the liquid oxygen rock breaking for tunnel excavation.

2. The manufacturing and assembling process of the tunnel boring liquid oxygen rock breaking device according to claim 1, characterized in that: The preparation steps for welding and assembling the fracturing device pipe body are as follows: 1) Preparation of fracture tubes: According to the design plan of the liquid oxygen rock breaking project, prepare round tubes of corresponding specifications and models with a certain size. The outer diameter of the tube of the tunnel excavation liquid oxygen rock breaking fracturer is preferably 40 to 70 mm; 2) Prepare a pipe cap with the same material and outer diameter as the fracturing device pipe, and a wall thickness not less than the wall thickness of the pipe. Two pipe caps are required to assemble a set of fracturing devices; 3) Prepare tools and equipment for assembly. Prepare pipe body welding machine, plug welding machine for pipe cap and exhaust pipe, hand drill, edge planer and through-hole shaping rod; 4) preparing the injection tube, exhaust pipe, biomass core, electric ignition head, electric ignition wire, and sleeve, wherein the length of the injection tube, exhaust pipe, and ignition wire is determined according to the design, the number of ignition heads is usually 1 to 2 per fracturing device, and the sleeve is preferably 10 cm long; 5) Prepare ohmmeter and other testing instruments.

3. The manufacturing and assembling process of the tunnel boring liquid oxygen rock breaking device according to claim 1, characterized in that: The cracker welding method is as follows: 1) The welding of the pipe body and the pipe cap of the fracturing device should be aligned and smooth without misalignment. The weld cutting should be smooth, and the outer diameter of the weld should not be larger than the pipe diameter of the fracturing device. 2) At the joints between the casing, exhaust pipe and pipe cap, there should be no blockage inside the pipe and the inner diameter should not be reduced; 3) The joints between the injection tube and the sleeve, the ignition wire and the small round hole of the tube cap should be firmly glued and waterproof, and the wire and injection tube should not be damaged during operation; 4) During planing and welding operations, workers should wear gloves and pay attention to electrical safety to avoid burns and planing injuries.

4. The manufacturing and assembling process of the tunnel boring liquid oxygen rock breaking device according to claim 1, characterized in that: One end of the pipe opening of the exhaust pipe is seamlessly plugged into the pipe cap of the fracturing device through hot melting.

5. The manufacturing and assembling process of the tunnel boring liquid oxygen rock breaking device according to claim 1, characterized in that: After passing through the closing device, the injection tube is butted against the injection mother tube.

6. The manufacturing and assembling process of the tunnel boring liquid oxygen rock breaking device according to claim 1, characterized in that: The foot wires of the electric ignition head are connected in parallel and then in series with the ignition wire. The connection points are wrapped with insulating tape and fixed to the biomass fuel core with tape.

7. The tunnel boring liquid oxygen rock breaking device according to claim 1 to claim 6, characterized in that: The invention comprises a fracturing device, a liquid injection pipe, an exhaust pipe, an electric ignition device and a biomass fuel core. The fracturing device is located in a blasthole of a tunnel excavation section, the biomass fuel core is installed in the fracturing device, the fracturing device is provided with two pipe caps, the electric ignition device is provided with an electric ignition head and an electric ignition wire, the exhaust pipe is seamlessly connected to the pipe cap of the fracturing device, and the fracturing device is made of thermoplastic material, has low temperature resistance, good waterproof sealing performance and high strength.

8. The tunnel boring liquid oxygen rock breaking device according to claim 7, characterized in that: The injection pipe and the exhaust pipe are both made of high molecular weight polyethylene, high density polyethylene or nylon 12 round tubes with good heat insulation and can be hot-melt processed. They have low temperature resistance, good waterproof sealing and high strength.

9. The tunnel boring liquid oxygen rock breaking device according to claim 7, characterized in that: The biomass fuel core is made of liquid oxygen explosion paper, or renewable biomass combustible raw materials such as straw powder, wood powder, and carbon powder.

10. The tunnel boring liquid oxygen rock breaking device according to claim 7, characterized in that: The thickness of the top structure of the pipe cap of the fracturing device is 5-7 mm, and the thickness of the pipe body of the fracturing device is 1.5-3.0 mm.

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