Coal dust-oxygen blasting device

Abstract

The present application relates to the field of energy exploitation, in particular to a kind of coal powder-oxygen blasting device, including the fine coal powder remaining in borehole, the film with good air tightness and toughness being arranged in borehole, oxygen supply device being connected with film by inflation pipe, and stop valve and pressure reducing valve being installed on inflation pipe, ignition head being arranged in film tail section, ignition head lead extending to the outside of expanded cement at film tail end.The raw materials of the present application are taken on site, coal is exploded with coal, the cost is low, the use of explosive is avoided, the danger and economic expense in the process of explosive transportation and storage are reduced, and the safety in the process of rock breaking operation is greatly improved;Compared with traditional explosive blasting, the present application has no residue after blasting and produces little toxic and harmful substances.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of energy exploitation, in particular to a coal powder-oxygen blasting device. BACKGROUND

[0002] In the process of coal mining, due to the different geological conditions of the coal seam, the mining tools and techniques are also different. Deep coal seams contain a large amount of undispersed gas, which poses a great threat to the lives of workers if the structure of the coal seam is damaged. The existing solution is to drill deep holes along the coal seam and extract the gas, and at the same time use the deep holes as blast holes to fill explosives to achieve blasting mining. However, the storage, transportation and delivery of explosives and detonators to the underground have always been a problem that needs to be solved.

[0003] On the other hand, according to the actual situation, the drilling depth is generally tens of meters to hundreds of meters, and the traditional charging method generally uses a long anchor cable to push a length of about 50 cm explosive charge into the hole bottom one section at a time. The anchor cable is very heavy, the construction labor intensity is huge, and the total length of the charge is long, the number of charge delivery is large, and the work efficiency is very low. Sometimes due to the deformation of the drilling hole or local collapse or blockage, charging is difficult to carry out, and the blasting effect is not good. At present, some people are developing automatic charging equipment, but the technology is still not mature and difficult to popularize. Therefore, for deep coal mining blasting, new ideas and processes are needed to solve these problems. SUMMARY

[0004] In order to improve the safety factor in coal mining and solve the problems of long operation cycle and low efficiency, the present application provides a coal powder-oxygen blasting device.

[0005] To achieve the above purpose, the technical scheme adopted by the present application is:

[0006] A coal powder-oxygen blasting device, comprising fine coal powder remaining in the drilling hole, a gas-tight and flexible film arranged in the drilling hole, an oxygen supply device connected to the film through an inflation pipe, a stop valve and a pressure reducing valve installed on the inflation pipe, an ignition head arranged in the tail section of the film, and an ignition lead extending to the outside of the expanded cement at the tail end of the film.

[0007] Further, the oxygen supply device fills high-pressure oxygen into the blast hole through the inflation pipe, and uses the density and expanded cement of the deep coal seam to fill the high-pressure oxygen in the blast hole, and uses the stop valve to maintain the sealing of the blast hole.

[0008] Further, after ignition, the fine coal powder is fully mixed with high-pressure oxygen, the specific surface area of the fine coal powder is large, and the fine coal powder will react rapidly under sufficient oxygen and high-pressure environment to form deflagration or even detonation, instantaneously release a large amount of heat and generate a large amount of gas, and the shock wave and the generated gas act on the coal seam to achieve blasting mining.

[0009] Further, the mass of the fine coal powder and the pressure of the high-pressure oxygen are configured based on the equivalence ratio of complete reaction.

[0010] Further, the thin film with good air tightness and toughness is a flexible thin bag, the oxygen supply device is a high-pressure oxygen cylinder or an oxygen generator vehicle, and the stop valve is a one-way valve or a check valve.

[0011] Further, for a plurality of blasting holes, a series method is used to achieve simultaneous pressure charging, and a delay device is used to achieve delay initiation of the entire blasting network.

[0012] The present application has the following beneficial effects:

[0013] (1) The safety in the rock breaking operation process is greatly improved, and the use of explosives is avoided, and for coal powder, explosion will not occur in the blast hole under normal pressure, which is very safe, even if the ignition device is triggered by mistake, and the personnel have evacuated to the safe area when the high-pressure reaches the dangerous state;

[0014] (2) Compared with the traditional explosive blasting, the reaction residues after blasting are few, and the toxic and harmful substances generated are few;

[0015] (3) The raw materials are taken on site, and the coal is blasted with coal, which is low in cost, reduces the danger and economic expenditure in the transportation and storage process, and the energy density of the coal quality is high, the total heat release of the coal is 4-5 times that of TNT under the same quality, and a large amount of gas is generated, which is very suitable for the fracturing mining of coal seams;

[0016] (4) The whole operation process is convenient and fast, which reduces the labor intensity and improves the coal mining efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0017] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments, made with reference to the accompanying drawings:

[0018] Figure 1 Fig. 1 is a structural schematic view of a coal powder-oxygen blasting device according to an embodiment of the present application;

[0019] In the figure: 1-coal seam, 2-residual fine coal powder in the drill hole, 3-thin film, 4-high-pressure oxygen, 5-ignition head, 6-swelling cement, 7-stop valve, 8-pressure reducing valve, 9-oxygen supply device, 10-gas charging pipe. DETAILED DESCRIPTION

[0020] The present application will be described in detail below with specific examples. The following examples will help those skilled in the art to further understand the present application, but do not limit the present application in any form. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application, which are within the scope of the present application.

[0021] As shown in Figure 1 A coal powder-oxygen blasting device according to an embodiment of the present application includes fine coal powder 2 remaining in a borehole, a flexible thin bag arranged in the borehole, a high-pressure oxygen tank or oxygen generator vehicle connected to the flexible thin bag through an inflation pipe 10, a one-way valve or check valve and a pressure reducing valve 8 installed on the inflation pipe 10, an ignition head 5 arranged in a tail section of the flexible thin bag, the ignition head 5 extending to the outside of an expanded cement 6 at a tail end of the flexible thin bag, and high-pressure oxygen 4 filled into the flexible thin bag through the inflation pipe 10 from the high-pressure oxygen tank or oxygen generator vehicle. The high-pressure oxygen in the entire borehole is filled using the strong constraint of the borehole itself in combination with the air tightness and flexibility of the flexible thin bag, and the sealing of the flexible thin bag is maintained using the one-way valve or check valve. In the specific implementation of the present application, first, a portion of fine coal powder is reserved in the borehole after air extraction in the coal mine, and a flexible thin bag is arranged along the borehole. The front end of the flexible thin bag is sealed, the ignition head and the inflation pipe are arranged at the tail end, and the tail end is filled with expanded cement. Then, the one-way valve or check valve and the pressure reducing valve 8 are installed on the inflation pipe, and the inflation pipe 10 is connected to the oxygen tank or oxygen generator vehicle. The high-pressure oxygen is filled into the hose through the one-way valve. The ignition is completed, and the blasting is completed.

[0022] In this embodiment, after ignition, the fine coal powder 2 is fully mixed with the high-pressure oxygen 4. The specific surface area of the fine coal powder 2 is large, and it will react quickly in an oxygen-rich and high-pressure environment to form deflagration or even detonation, instantaneously release a large amount of heat and generate a large amount of gas. The shock wave and the explosion gas formed act on the coal seam 1 to achieve blasting mining, and the main reaction is C+O2=CO2.

[0023] In order to improve the utilization rate of raw materials and the blasting power, the mass of the fine coal powder 2 and the pressure of the high-pressure oxygen 4 are configured based on the equivalence ratio of complete reaction in this embodiment.

[0024] It is worth noting that, according to the site construction conditions, the flexible thin bag can be replaced with other thin films with good air tightness and toughness.

[0025] For multiple blasting holes, a series connection method can be used to achieve simultaneous pressure charging, and a delay device can be used to achieve delay initiation of the entire blasting network.

[0026] The principle of the present application is to:

[0027] 1) Upon ignition, the flexible thin bag breaks, and high-pressure oxygen mixes thoroughly with pulverized coal within the borehole. Due to the large specific surface area of ​​the fine pulverized coal, and the high pressure causing rapid combustion, a detonation occurs within the borehole, releasing a large amount of heat and generating a large amount of gas. The resulting shock wave crushes the coal seam near the borehole wall, creating radial fractures outside the crushed area. Subsequently, the explosive gas produces a "gas wedge effect," further extending and opening the fractures, thus breaking the rock. The following formula shows that the reaction rate for small-diameter solid particles is positively correlated with pressure.

[0028]

[0029] In the formula, R c For the reaction rate of a solid, k c ' is the Arrhenius rate constant, M r,mix V represents the mass fraction of the mixed gas surrounding the particles, P represents the ambient pressure, and v represents the mass fraction of the mixed gas surrounding the particles. I R is the equilibrium parameter for the gas-solid reaction. u Let T be the ideal gas constant. s ω represents the temperature of the solid particles. O2,s This represents the molar concentration of oxygen at the surface of the solid particles. All parameters except pressure P and solid particle temperature T are considered. s Apart from the other parameters, which are deterministic constants for solid particles, high pressure helps to accelerate the reaction rate between the gas and solid phases.

[0030] 2) The high-pressure oxygen can be filled into the entire borehole by utilizing the strong constraint of the borehole itself combined with the airtightness and flexibility of the rubber tube.

[0031] This invention can also be used for blasting mining of rocks and other materials in mines. It only requires providing a strong confinement container to replace the function of the borehole wall and maintain high pressure within the system.

[0032] Example 1

[0033] refer to Figure 1 A 1.5mm thick steel cylinder was used to simulate the constraints of coal seam drilling. The cylinder had a total volume of 1.6L, a diameter of 200mm, and an inner diameter of 100mm. The device was cylindrical and filled with 180g of pulverized coal (micrometer-diameter) at a density of approximately 0.11g / cm³. The ignition head and filling pipe were connected to the cylinder via threaded connections and adhesive sealing to create a sealed environment. A one-way valve and a pressure reducing valve were used to connect it to a high-pressure oxygen cylinder. During the experiment, the cylinder was filled with 8MPa of industrial oxygen (99.9% purity). The one-way valve prevented gas leakage and maintained high pressure. Ignition by the ignition head caused the cylinder wall to explode and shatter into dozens of steel fragments less than 2cm in diameter and a large amount of small iron filings. The shattering of the cylinder indicates that the explosion after ignition, rather than gas expansion tearing, demonstrates the feasibility of the invention.

[0034] The specific embodiments of the present application are described above. It needs to be understood that the present application is not limited to the specific embodiments described above, and various modifications or changes can be made by those skilled in the art within the scope of the claims, which do not affect the essence of the present application.

Claims

1. A pulverized coal-oxygen explosion device, characterized in that: The system includes fine coal powder (2) remaining in the borehole, a membrane (3) with good airtightness and toughness arranged in the borehole, an oxygen supply device (9) connected to the membrane (3) through an air filling pipe (10), and a shut-off valve (7) and a pressure reducing valve (8) installed on the air filling pipe (10). An ignition head (5) is arranged in the tail section of the membrane (3), and the lead wire of the ignition head (5) extends to the outside of the expansive cement (6) at the tail end of the membrane (3). The membrane (3) with good airtightness and toughness is a flexible thin bag. The oxygen supply device (9) fills the membrane (3) with high-pressure oxygen (4) through the air filling pipe (10). The high-pressure oxygen is filled in the entire borehole by utilizing the density of the deep coal seam itself and the expansive cement (6), and the shut-off valve (7) is used to maintain the seal of the borehole.

2. The pulverized coal-oxygen explosion device as described in claim 1, characterized in that: After ignition, fine coal powder (2) is fully mixed with high-pressure oxygen (4). Fine coal powder (2) has a large specific surface area and will react quickly in a high-pressure environment with sufficient oxygen, forming deflagration or even detonation, instantly releasing a large amount of heat and generating a large amount of gas. The resulting shock wave and explosive gas act on the coal seam (1) to achieve blasting mining.

3. The pulverized coal-oxygen explosion device as described in claim 1, characterized in that: The mass of fine coal powder (2) and the pressurization of high-pressure oxygen (4) are configured based on the equivalence ratio of complete reaction.

4. The pulverized coal-oxygen explosion device as described in claim 1, characterized in that: The oxygen supply device (9) is a high-pressure oxygen cylinder or an oxygen generator; the shut-off valve (7) is a one-way valve or a check valve.

5. The pulverized coal-oxygen explosion device as described in claim 1, characterized in that: For multiple blasting holes, a series method is used to achieve simultaneous pressurization, while a delay device is used to delay the detonation of the entire blasting network.

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