Gas expansion pipe for mining

Abstract

The invention discloses a gas expansion pipe for mining, which comprises a double-layer vacuum pipe body, an electronic controller with an FPGA (Field Programmable Gate Array) control chip, a nanocrystalline / graphene composite heat conduction rod, a CuO / Al / PTFE (Polytetrafluoroethylene) composite gas-making agent and a protection part with a conical injection cavity, the protection part with the conical injection cavity is arranged at one end of the double-layer vacuum pipe body, and the protection part with the conical injection cavity is arranged at the other end of the double-layer vacuum pipe body. A piezoelectric ceramic-phase change material-ultra-high molecular weight polyethylene composite protective layer is adopted for the protective part with the conical jet cavity, the protective part can bear 8MPa internal pressure impact, the permanent deformation is smaller than 0.5 mm, and an overpressure anti-explosion valve is arranged at the other end of the double-layer vacuum tube body. By means of electronic control, when micro-current passes through the high-heat-conduction rod, high temperature is generated, a gas making agent is rapidly expanded to generate high-pressure shock waves to rapidly release high-pressure gas, blasting objects or deposits are rapidly propelled outwards by geometric-level equivalent shock waves, the whole process from detonation to ending only needs 0.4 millisecond, and efficiency is high; and the defects of great destructiveness, high risk, ore body crushing and the like in the conventional explosive blasting mining and presplitting are overcome.

Description

Technical Field

[0001] This invention relates to the field of blasting technology in mining, specifically to a gas expansion pipe for mining. Background Technology

[0002] Traditional mining blasting techniques suffer from high risks associated with explosive storage, uncontrollable shock waves, and significant environmental damage. Explosive blasting also produces toxic gases (NO2, CO, etc.) and dust pollution, failing to meet the requirements for green mine construction. Gas blasting technology, on the other hand, utilizes the vaporization of easily vaporized liquids or the chemical reaction of solids to generate high-pressure gas. This gas causes the surrounding medium to expand and break apart, offering advantages such as no open flame, safety, and high efficiency.

[0003] Existing gas blasting devices mainly consist of a vaporization reservoir and a heating detonator installed inside the vaporization reservoir. After ignition, the heating detonator vaporizes the easily vaporizable substances in the vaporization reservoir, leading to an expansion explosion. The detonator structure in existing gas blasting devices primarily involves loading the heat-generating chemical reactants into a metal mesh tube via a loading belt, and encapsulating the heating wire within the chemical reactants. For example, application CN2514304Y discloses a cryogenic gas blasting device. This type of detonator structure requires pre-filling with an oxidizing agent and a reducing agent capable of generating a heat-generating reaction. Powdered oxidizing and reducing agents are commonly used. Commonly used oxidizing agents include sulfur, potassium nitrate, potassium perchlorate, and potassium permanganate; commonly used reducing agents include aluminum powder and carbon powder. A common reaction mixture is sulfur, potassium nitrate, and carbon powder, and its reaction equation is:

[0004] S + 2KNO3 + 3C = K2S + N2↑ + 3CO2↑, commonly known as the black powder reaction, has a relatively low cost. However, the above-mentioned detonator has some shortcomings: the current resistance wire heating method has an electrical energy-to-thermal energy conversion efficiency of only about 45%, requiring high-power power supply equipment and increasing energy consumption in downhole operations; the decomposition temperature of the gas-generating agent exceeds 270℃, and it takes 1.2-1.5 seconds from heating to gas expansion, which is difficult to meet the millisecond-level precise control requirements; after the explosion, the reactants in the detonator produce a large amount of toxic and harmful gases, such as hydrogen sulfide, sulfur dioxide, nitric oxide, and nitrogen dioxide, causing significant toxic pollution to the blasting site; the lack of a directional shock wave design makes the tube body prone to plastic deformation due to internal overpressure, requiring frequent replacement. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defects of the above-mentioned technology and provide a gas expansion pipe for mining.

[0006] To solve the above-mentioned technical problems, the present invention provides a gas expansion pipe for mining operations, comprising:

[0007] The double-layer vacuum tube body is forged from Ti-6Al-4V titanium alloy with a yield strength ≥880MPa and an inner wall electroplated with a 0.3mm thick Al2O3 ceramic layer for corrosion resistance.

[0008] An electronic controller with an FPGA control chip is provided. The double-layer vacuum tube body is equipped with an electronic control chamber. The electronic controller with an FPGA control chip is located in the electronic control chamber. The electronic controller with an FPGA control chip adopts a closed-loop PID control algorithm and has a temperature control accuracy of ±2℃.

[0009] A nanocrystalline / graphene composite thermal conductive rod is installed inside a double-layer vacuum tube and electrically connected to an electronic controller with an FPGA control chip. The nanocrystalline / graphene composite thermal conductive rod is made of Fe. 80 Si9B 11 The substrate is a nanocrystalline alloy coated with a graphene / silicon carbide composite coating, with a radial temperature gradient of <5℃ / mm.

[0010] CuO / Al / PTFE composite gas generator, wherein the CuO / Al / PTFE composite gas generator is disposed inside a double-layer vacuum tube and is in the form of a compressed block;

[0011] The protective part with a conical jet cavity is located at one end of the double-layer vacuum tube. The protective part with the conical jet cavity adopts a piezoelectric ceramic-phase change material-ultra-high molecular weight polyethylene composite protective layer, which can withstand an internal pressure impact of 8MPa and a permanent deformation of <0.5mm.

[0012] The other end of the double-layer vacuum tube is equipped with an overpressure explosion-proof valve.

[0013] Furthermore, the gas-generating agent comprises 45% CuO, 35% Al and 20% PTFE by mass ratio, and is produced by cold isostatic pressing with an initial reaction temperature of 180℃±5℃.

[0014] Furthermore, the double-layer vacuum tube body includes an outer tube, an inner tube, and a vacuum interlayer. The outer tube has an outer diameter of 42 mm and a wall thickness of 5 mm; the inner tube has an outer diameter of 36 mm and a wall thickness of 3 mm; the vacuum interlayer has a vacuum degree of 0.1 Pa and is filled with nano-aerogel insulation material.

[0015] The outer and inner tubes are laser-welded together, and leak detection is performed using helium mass spectrometry, with a leakage rate of <1×10⁻⁶. -9 Pa·m 3 / s, ensuring a 5-year service life.

[0016] Furthermore, in the nanocrystalline / graphene composite thermal conductive rod: Fe 80 Si9B 11The grain size of the nanocrystalline alloy is <50nm, and the thickness of the graphene / silicon carbide composite coating is 5μm.

[0017] The nanocrystalline / graphene composite heat-conducting rod has a diameter of 8mm ± 0.02mm, and its length is adapted to the length of the double-layer vacuum tube: L = tube length × 0.8, and its surface roughness: Ra < 0.4μm.

[0018] Furthermore, the conical spray cavity of the protective part with the conical spray cavity has an inlet diameter of 12mm, an outlet diameter of 6mm, and a cone angle of 120°. The inner layer of the composite protective layer is PZT-5H piezoelectric ceramic with a thickness of 2mm, the middle layer is paraffin / graphite phase change material with a melting point of 45℃, and the outer layer is ultra-high molecular weight polyethylene with a thickness of 3mm. A sealing membrane is provided at the outlet of the conical spray cavity.

[0019] The advantages of this invention compared to existing technologies are as follows: This product is a completely environmentally friendly alternative for mining without the use of explosives. Through electronic control, when a microcurrent passes through a high-thermal-conductivity rod, high temperatures are generated, causing the gasifying agent to expand rapidly and generate a high-pressure shock wave that quickly releases high-pressure gas. The blasted material or deposit is propelled outward rapidly by the geometrically equivalent shock wave. The entire process from detonation to completion takes only 0.4 milliseconds, making the product highly efficient. This product operates at low temperatures, does not mix with surrounding liquids or gases, does not produce any harmful gases, and is unaffected by high temperatures, high humidity, or extreme cold. It solves the shortcomings of traditional explosive blasting and pre-splitting methods, such as high destructiveness, high risk, and ore body crushing. It provides a reliable guarantee for safe mining and pre-splitting, significantly improving blasting efficiency and reducing safety risks. It is widely applicable to both coal mines and non-coal mines. This product is small in size, lightweight, easy to install, safe, and convenient. While its performance is slightly inferior to explosives and its cost is slightly higher, it is safe, environmentally friendly, and in line with national conditions. Attached Figure Description

[0020] Figure 1 This is a cross-sectional structural schematic diagram of a gas expansion pipe used in mining according to the present invention.

[0021] Figure 2 This is a schematic diagram of the structure of a gas expansion pipe used in mining according to the present invention.

[0022] As shown in the figure:

[0023] 1. Double-layer vacuum tube body; 2. Electronic controller; 3. Nanocrystalline / graphene composite heat-conducting rod; 4. CuO / Al / PTFE composite gas generator; 5. Protective part with conical injection cavity; 6. Overpressure explosion-proof valve; 7. Sealing membrane. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0025] Example 1, in conjunction with Appendix Figure 1-2 A gas expansion pipe for mining operations includes:

[0026] The double-layer vacuum tube body 1 is forged from Ti-6Al-4V titanium alloy with a yield strength ≥880MPa and an inner wall electroplated with a 0.3mm thick Al2O3 ceramic layer for corrosion resistance.

[0027] An electronic controller 2 with an FPGA control chip is provided. The double-layer vacuum tube body 1 is provided with an electronic control chamber. The electronic controller 2 with an FPGA control chip is located in the electronic control chamber. The electronic controller 2 with an FPGA control chip adopts a closed-loop PID control algorithm and has a temperature control accuracy of ±2℃.

[0028] A nanocrystalline / graphene composite heat-conducting rod 3 is installed inside a double-layer vacuum tube 1 and electrically connected to an electronic controller 2 with an FPGA control chip. The nanocrystalline / graphene composite heat-conducting rod 3 is made of Fe. 80 Si9B 11 The substrate is a nanocrystalline alloy coated with a graphene / silicon carbide composite coating, with a radial temperature gradient of <5℃ / mm.

[0029] CuO / Al / PTFE composite gas generator 4, wherein the CuO / Al / PTFE composite gas generator 4 is disposed inside the double-layer vacuum tube 1 and is in the form of a compressed block;

[0030] The protective part 5 with a conical jet cavity is located at one end of the double-layer vacuum tube 1. The protective part 5 with a conical jet cavity adopts a piezoelectric ceramic-phase change material-ultra-high molecular weight polyethylene composite protective layer, which can withstand an internal pressure impact of 8MPa and a permanent deformation of <0.5mm.

[0031] The other end of the double-layer vacuum tube 1 is equipped with an overpressure explosion-proof valve 6.

[0032] The gas-generating agent comprises 45% CuO, 35% Al and 20% PTFE by mass, and is produced by cold isostatic pressing with an initial reaction temperature of 180℃±5℃.

[0033] The double-layer vacuum tube 1 includes an outer tube, an inner tube, and a vacuum interlayer. The outer tube has an outer diameter of 42 mm and a wall thickness of 5 mm; the inner tube has an outer diameter of 36 mm and a wall thickness of 3 mm; the vacuum interlayer has a vacuum degree of 0.1 Pa and is filled with nano-aerogel insulation material.

[0034] The outer and inner tubes are laser-welded together, and leak detection is performed using helium mass spectrometry, with a leakage rate of <1×10⁻⁶. -9 Pa·m 3 / s, ensuring a 5-year service life.

[0035] In the nanocrystalline / graphene composite heat-conducting rod 3: Fe 80 Si9B 11 The grain size of the nanocrystalline alloy is <50nm, and the thickness of the graphene / silicon carbide composite coating is 5μm.

[0036] The nanocrystalline / graphene composite heat-conducting rod 3 has a diameter of 8mm ± 0.02mm, and its length is adapted to the length of the double-layer vacuum tube 1: L = tube length × 0.8. Surface roughness: Ra < 0.4μm. Heating rate: 1200℃ / ms, radial temperature gradient: < 5℃ / mm, thermal cycle life: > 1000 cycles.

[0037] The conical spray cavity of the protective part 5 with the conical spray cavity has an inlet diameter of 12mm, an outlet diameter of 6mm, and a cone angle of 120°. The inner layer of the composite protective layer is PZT-5H piezoelectric ceramic with a thickness of 2mm, the middle layer is paraffin / graphite phase change material with a melting point of 45℃, and the outer layer is ultra-high molecular weight polyethylene with a thickness of 3mm. Through dynamic response testing, under an impact pressure of 8MPa (peak), the deformation is <0.5mm (permanent deformation) and the recovery time is <1s (90% deformation recovery). The outlet of the conical spray cavity is sealed with a sealing membrane 7.

[0038] The inner side of the inner tube of the double-layer vacuum tube 1 is provided with a spiral guide groove along the axial direction, and the ratio of the depth of the spiral guide groove to the tube diameter is 0.12-0.15.

[0039] The overpressure explosion-proof valve 6 is an electromagnetically driven explosion-proof valve, which includes a permanent magnet, an electromagnetic coil and an elastic sealing diaphragm. When the pressure inside the double-layer vacuum tube 1 exceeds the set threshold, the electromagnetic coil is energized to generate a reverse magnetic field, causing the sealing diaphragm to open the pressure relief channel within 0.5ms, thus preventing the double-layer vacuum tube 1 from exploding.

[0040] In use, the lithological parameters of the target area are obtained through ground-penetrating radar and input into the electronic control unit to establish a three-dimensional geological model. The microprocessor calculates the required shock wave equivalent based on the model and determines the current pulse parameters (amplitude, frequency, and pulse width). The electronic controller 2 with an FPGA control chip controls the pulse generator to output the required pulse current, which causes the nanocrystalline / graphene composite heat-conducting rod to heat up instantly. The CuO / Al / PTFE composite gas generator reacts with heat to produce high-temperature and high-pressure gas, which is accelerated through the spiral guide channel to form a shock wave. The high-pressure gas is rapidly released through the outlet of the conical injection cavity. The blasted object or pile is rapidly propelled outward by the geometric equivalent shock wave, thus achieving blasting.

[0041] The circuit architecture of the electronic controller 2, which includes an FPGA control chip, is as follows:

[0042] Power module: Input DC24V, output adjustable range 0-120V;

[0043] Pulse generator: based on Buck-Boost topology, duty cycle adjustment accuracy 0.1%;

[0044] Feedback loop: Closed-loop PID control is adopted, and the temperature response speed is <20ms;

[0045] Core Algorithm

[0046] / / Temperature control algorithm pseudocode

[0047] float Kp=0.8, Ki=0.05, Kd=0.1;

[0048] float error,integral=0,derivative;

[0049] float setpoint = 180.0; / / Target temperature in °C

[0050] void PID_Control(){

[0051] float current_temp=read_temp_sensor();

[0052] error=setpoint-current_temp;

[0053] integral += error * dt;

[0054] derivative=(error-prev_error) / dt;

[0055] float output=Kp*error+Ki*integral+Kd*derivative;

[0056] adjust_power(output);

[0057] prev_error = error;

[0058] }

[0059] In this scheme, for the CuO / Al / PTFE composite gas generator: CuO acts as an oxidant, providing heat of reaction; Al acts as a reducing agent, generating a high-temperature reaction; and PTFE acts as a binder, controlling the reaction rate.

[0060] When the temperature of the heat-conducting rod reaches 180℃, the gas-generating agent reaction is triggered:

[0061] 3CuO + 2Al → Al₂O₃ + 3Cu + 1.5O₂↑

[0062] Along with the pyrolysis of PTFE, gases such as CF4 and C2F4 are produced. The overall reaction formula is:

[0063] 3CuO+2Al+(C2F4)n→Al2O3+3Cu+4nCF2↑+1.5O2↑+Q

[0064] In the description of the embodiments of the present invention, it should be noted that if terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first," "second," and "third" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0065] Furthermore, the use of terms such as "horizontal," "vertical," and "sag" does not imply that the component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0066] In the description of the embodiments of the present invention, "multiple" means at least two.

[0067] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0068] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A gas expansion pipe for mining operations, characterized in that... include: Double-layer vacuum tube (1), wherein the double-layer vacuum tube (1) is forged from Ti-6Al-4V titanium alloy with a yield strength ≥880MPa and an inner wall electroplated with a 0.3mm thick Al2O3 ceramic layer for corrosion resistance; An electronic controller (2) with an FPGA control chip is provided in the double-layer vacuum tube body (1), and the electronic controller (2) with an FPGA control chip is located in the electronic control chamber. The electronic controller (2) with an FPGA control chip adopts a closed-loop PID control algorithm with a temperature control accuracy of ±2℃. A nanocrystalline / graphene composite thermal conductive rod (3) is installed inside a double-layer vacuum tube (1) and electrically connected to an electronic controller (2) with an FPGA control chip. The nanocrystalline / graphene composite thermal conductive rod (3) is made of Fe 80 Si9B 11 The substrate is a nanocrystalline alloy coated with a graphene / silicon carbide composite coating, with a radial temperature gradient of <5℃ / mm. CuO / Al / PTFE composite gas generator (4), wherein the CuO / Al / PTFE composite gas generator (4) is disposed inside the double-layer vacuum tube (1) and is in the form of a compressed block; The protective part (5) with a conical spray cavity is located at one end of the double-layer vacuum tube (1). The protective part (5) with a conical spray cavity adopts a piezoelectric ceramic-phase change material-ultra-high molecular weight polyethylene composite protective layer, which can withstand an internal pressure impact of 8MPa and a permanent deformation of <0.5mm. The other end of the double-layer vacuum tube (1) is equipped with an overpressure explosion-proof valve (6).

2. A gas expansion pipe for mining operations according to claim 1, characterized in that: The gas-generating agent comprises 45% CuO, 35% Al and 20% PTFE by mass, and is produced by cold isostatic pressing with an initial reaction temperature of 180℃±5℃.

3. A gas expansion pipe for mining according to claim 1, characterized in that: The double-layer vacuum tube (1) includes an outer tube, an inner tube, and a vacuum interlayer. The outer tube has an outer diameter of 42 mm and a wall thickness of 5 mm. The inner tube has an outer diameter of 36 mm and a wall thickness of 3 mm. The vacuum interlayer has a vacuum degree of 0.1 Pa and is filled with nano-aerogel insulation material. The outer and inner tubes are laser-welded together, and leak detection is performed using helium mass spectrometry, with a leakage rate of <1×10⁻⁶. -9 Pa·m 3 / s, ensuring a 5-year service life.

4. A gas expansion pipe for mining operations according to claim 1, characterized in that: In the nanocrystalline / graphene composite thermal rod (3): Fe 80 Si9B 11 The grain size of the nanocrystalline alloy is <50nm, and the thickness of the graphene / silicon carbide composite coating is 5μm. The nanocrystalline / graphene composite heat-conducting rod (3) has a diameter of 8mm ± 0.02mm and a length adapted to the length of the double-layer vacuum tube (1): L = tube length × 0.8, and a surface roughness: Ra < 0.4μm.

5. A gas expansion pipe for mining according to claim 1, characterized in that: The conical spray cavity of the protective part (5) with the conical spray cavity has an inlet diameter of 12mm, an outlet diameter of 6mm, and a cone angle of 120°. The inner layer of the composite protective layer is PZT-5H piezoelectric ceramic with a thickness of 2mm. The middle layer is paraffin / graphite phase change material with a melting point of 45℃. The outer layer is ultra-high molecular weight polyethylene with a thickness of 3mm. A sealing membrane (7) is provided at the outlet of the conical spray cavity.

6. A gas expansion pipe for mining according to claim 3, characterized in that: The inner side of the inner tube of the double-layer vacuum tube (1) is provided with a spiral guide groove along the axial direction, and the ratio of the depth of the spiral guide groove to the diameter of the tube is 0.12-0.

15.

7. A gas expansion pipe for mining according to claim 1, characterized in that: The overpressure explosion-proof valve (6) is an electromagnetically driven explosion-proof valve, which includes a permanent magnet, an electromagnetic coil and an elastic sealing diaphragm. When the pressure inside the double-layer vacuum tube (1) exceeds the set threshold, the electromagnetic coil is energized to generate a reverse magnetic field, causing the sealing diaphragm to open the pressure relief channel within 0.5ms, thus preventing the double-layer vacuum tube (1) from exploding.

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