A flexible leak-proof device and method for wind curtain wall in goaf area with top-cut goaf-retaining lane

Abstract

The present invention belongs to the technical field of coal pillar-free mining and goaf disaster prevention in mines, and specifically is a flexible leak-proof device and method for wind curtain walls in goafs along goafs in top-cut goafs. It comprises a compressed air pipeline arranged in the transport chute and the track chute, and a wind curtain wall generating device arranged in the air inlet corner, the transport chute and the goafs along the return air side, which is at a certain distance from the goaf wall and slightly below the roof; the wind curtain wall generating device is connected to the compressed air pipeline, and the compressed air pipeline provides compressed air. The wind curtain wall generating device generates a plane jet wind curtain wall, and utilizes the resistance-increasing and pressure-increasing effect of the wind curtain wall to cut off the leakage flow field in the goafs along goafs in top-cut goafs. The present invention can make full use of the existing compressed air pipeline network, and has the dual functions of resistance-increasing and pressure-increasing leak-proofing, and at the same time has good leak-proofing effect, is pollution-free, does not affect the normal production of the working face, and can effectively prevent and control gas and spontaneous combustion disasters in goafs along goafs in top-cut goafs.

Description

Technical Field

[0001] The invention belongs to the technical field of coal pillar-free mining and goaf disaster prevention in mines, and in particular is a flexible leak plugging device and method for a wind curtain wall in a goaf with a top-cut goaf-retaining lane. Background Art

[0002] The first two explorations of technological transformation in China's mining industry were the 121 Large Coal Pillar Method, based on the masonry beam theory proposed by Academician Qian Minggao of the Chinese Academy of Engineering, and the 121 Small Coal Pillar Method, based on the transfer rock beam theory proposed by Academician Song Zhenqi of the Chinese Academy of Sciences. The 110 Method, a pillar-free, self-forming tunneling mining technology, represents the third exploration of technological transformation in my country's mining industry. This technology was proposed at the beginning of this century by a research team led by Academician He Manchao from the State Key Laboratory of Deep Geotechnical Mechanics and Underground Engineering at the China University of Mining and Technology (Beijing). Currently, research focuses on the principles and processes of pillar-free tunneling, roof collapse mechanical models, surrounding rock stress distribution, the mechanical mechanisms of concentrated charge blasting during pre-splitting and slit blasting, and new materials for constant resistance, large deformation, and anti-bumping support. However, limited research has been conducted on the safety issues associated with ventilation during the implementation of this technology.

[0003] A key challenge faced in mining using top-cutting and pressure-relieving mining technology is goaf management. Because the main section of the retained laneway is the caving zone of the goaf, the goaf is completely exposed within the laneway, creating a completely open state. Compared to the hermetically sealed goaf of traditional mining techniques, the goaf is not sealed, resulting in relatively severe air leakage. Under negative pressure, harmful gases within the goaf easily leak into the laneway, increasing the difficulty of managing these gases. Furthermore, due to the relatively high air leakage in the goaf, the gas inerting process in the goaf is slow or even ceases. The residual coal in the goaf is easily oxidized under high oxygen conditions, further complicating goaf fire prevention and control.

[0004] At present, wind tube cloth is often laid between the steel mesh and U-shaped steel support in the temporary support area to temporarily seal the goaf. However, the wind tube cloth is easy to break and can only provide limited closure of the goaf in the short term. In order to solve the shortcomings of temporary closure, it is also necessary to permanently seal the goaf along the goaf. The commonly used permanent closure method is to spray air-plugging materials on the exposed wall surface of the goaf. Air-plugging materials generally include inorganic and organic materials. Inorganic materials have low cost and low pollution, but the plugging wall is easy to crack, the seal is not tight, and the plugging effect is poor. Organic materials have good plugging effects, but have disadvantages such as large dosage, high cost, and serious pollution. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a flexible leak-proof device and method for a wind curtain wall in a goaf area with a top-cut goaf-retaining lane.

[0006] The present invention adopts the following technical scheme: a flexible leakage plugging device for the wind curtain wall in the goaf of the cut-top goaf-retained lane, including a compressed air pipeline arranged in the transport chute and the track chute, and a wind curtain wall generating device arranged in the air inlet corner, the transport chute and the goaf-retained lane on the return air side at a certain distance from the wall of the goaf and below the top plate; the wind curtain wall generating device is connected to the compressed air pipeline, and compressed air is provided by the compressed air pipeline. The wind curtain wall generating device generates a plane jet wind curtain wall, and utilizes the resistance-increasing-pressure-increasing effect of the wind curtain wall to isolate the leakage flow field in the goaf of the cut-top goaf-retained lane.

[0007] In some embodiments, the wind curtain wall generating device includes multiple main wind tubes connected in sequence, with an upper air outlet set on the upper side of the main wind tube and a lower air outlet set on the lower side of the main wind tube. The upper air outlet and the lower air outlet spray air curtains in the upper and lower directions respectively.

[0008] In some embodiments, the upper air outlet is provided with an upper air outlet wind shield, one end of the upper air outlet wind shield is connected to the baffle puller, and the upper air outlet baffle tractor is connected to the upper air outlet baffle adjustment knob. The upper air outlet baffle tractor is driven by rotating the upper air outlet baffle adjustment knob, and the traction function of the tractor is used to adjust the rotation angle of the upper air outlet wind shield. The upper air outlet is provided with an upper air outlet grille, and the deflection angle of the upper air outlet grille is adjusted by the upper air outlet grille adjustment knob.

[0009] In some embodiments, the lower air outlet is provided with a lower air outlet wind shield, one end of the lower air outlet wind shield is connected to the baffle puller, and the lower air outlet baffle tractor is connected to the lower air outlet baffle adjustment knob. The lower air outlet baffle tractor is driven by rotating the lower air outlet baffle adjustment knob, and the traction function of the tractor is used to adjust the rotation angle of the lower air outlet wind shield. The lower air outlet is provided with a lower air outlet grille, and the deflection angle of the grille of the lower air outlet grille is adjusted by the lower air outlet grille adjustment knob.

[0010] In some embodiments, two adjacent main air ducts are connected by a four-way valve, and the four-way valve is provided with a first connecting port, a second connecting port, a third connecting port and a fourth connecting port. The first connecting port and the second connecting port are used to connect the front and rear sections of the main air duct, the third connecting port is closed or used to connect the wind curtain generating device at the air inlet corner, and the fourth connecting port is connected to the compressed air pipeline. The upper and lower ends of the four-way valve are provided with an upper air outlet strip and a lower air outlet strip of fixed width, which are used to connect with the upper air outlet and the lower air outlet respectively.

[0011] A method for using a flexible leak-proof device for a wind curtain wall in a goaf area with a top-cut goaf-retaining entry includes the following steps:

[0012] S100: After the mining working face is formed, a multi-section air curtain generating device is arranged in parallel to the compressed air pipeline in the transport chute at a certain distance from the wall of the goaf; an air curtain generating device with a length equal to the width of the tunnel is installed at the air inlet corner, and the air curtain generating device is fixed by a metal bracket.

[0013] S200: After the working surface starts working, air is supplied to the air curtain generating device, and the air volume, wind speed and air flow direction of the air curtain are adjusted;

[0014] S300: As the working face advances forward, the area of ​​the goaf gradually expands, and the goaf-retained lane on the return air side gradually takes shape. While the air curtain generating device in the transport chute is recovered, the air curtain generating device is gradually deployed along the goaf-retained lane on the return air side. The layout method is the same as that of the goaf-retained lane on the air inlet side.

[0015] S400: As the working face continues to advance, the wind curtain wall at the air inlet corner gradually moves forward, the wind curtain wall of the transport chute gradually shortens, and the wind curtain wall along the empty lane on the return air side gradually lengthens until the entire working face completes the operation.

[0016] S500: When the working face is mined, all the air curtain generating devices of the transport chute are recovered, and the air curtain generating devices of the return air side goaf are arranged; when the next working face is mined, the goaf of the return air side of the previous working face becomes the goaf of the inlet air side of the new mining working face, and the cycle repeats.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) An air curtain is built on the main air leakage channel in the goaf of the goaf with the top cut and the goaf retained to perform flexible plugging management. This invention can make full use of the existing compressed air pipe network and has the dual functions of increasing resistance and increasing pressure to plug leaks. It also has the significant advantages of good plugging effect, no pollution, no impact on normal production of the working face, and simple process flow. It can effectively prevent and control gas and spontaneous combustion disasters in the goaf of the goaf with the top cut and the goaf retained.

[0019] (2) While forming air curtain walls at the upper and lower ends of the main air duct, flexible adjustment of parameters such as the jet angle, air outlet width, and air outlet speed of the air curtain wall can be achieved.

[0020] (3) The air curtain device can be recovered and recycled during the advancement of the working face. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the goaf area with flexible sealing of the top cut and goaf-side entry by the wind curtain wall;

[0022] Figure 2 This is a schematic diagram of the flexible leakage prevention and disaster control effect of the wind curtain wall in the goaf area of ​​the goaf with the top cut and the goaf retained;

[0023] Figure 3 This is a three-dimensional diagram of the air curtain generating device along the gob-side lane retention on the air inlet side;

[0024] Figure 4 It is a schematic diagram of a four-way valve;

[0025] Figure 5 This is a schematic diagram of the interior of the air curtain device;

[0026] In the figure: 1- transport chute (air inlet side gob retention), 2- track chute, 3- return air side gob retention, 4- return air side air curtain generator, 5- air inlet corner air curtain generator, 6- compressed air pipeline, 7- air inlet corner, 8- return air lane of the next working face, 9- main air duct, 10- upper air outlet, 10.1 upper air outlet baffle adjustment knob, 10.2- upper air outlet grille, 10.3- upper air outlet wind baffle, 10.4- upper air outlet baffle tractor, 10.5- upper air outlet grille adjustment Knob, 11-lower air outlet, 11.1-lower air outlet baffle adjustment knob, 11.2-lower air outlet grille, 11.3-lower air outlet wind deflector, 11.4-lower air outlet baffle tractor, 11.5-lower air outlet grille adjustment knob, 12-four-way valve, 12.1-upper air outlet strip, 12.2-lower air outlet strip, 12.3-first connecting port, 12.4-second connecting port, 12.5-third connecting port, 12.6-fourth connecting port, 13-air inlet side wind curtain generating device. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0028] like Figure 1 As shown, a flexible leakage plugging device for the wind curtain wall in the goaf of the cut-top goaf-retained lane includes a compressed air pipeline 6 arranged in the transport chute 1 and the track chute 2, and a wind curtain wall generating device arranged in the air inlet corner 7, the transport chute 1 and the goaf-retained lane 3 on the return air side at a certain distance from the wall of the goaf and below the roof; the wind curtain wall generating device is connected to the compressed air pipeline 6, and compressed air is provided by the compressed air pipeline 6. The wind curtain wall generating device generates a plane jet wind curtain wall, and utilizes the resistance-increasing-pressure-increasing effect of the wind curtain wall to isolate the leakage flow field in the goaf of the cut-top goaf-retained lane.

[0029] As the top cutting and goaf retaining working face continues to advance, the air inlet corner wind curtain generating device 5 gradually moves forward, the air inlet side wind curtain generating device 13 gradually shortens, and the return air side wind curtain generating device 4 gradually lengthens until the entire mining working face is completed.

[0030] like Figure 3 As shown, the wind curtain wall generating device includes a plurality of main air ducts 9 connected in sequence, an upper air outlet 10 is provided on the upper side of the main air duct 9, and a lower air outlet 11 is provided on the lower side of the main air duct 9. The upper air outlet 10 and the lower air outlet 11 spray air curtains in the upper and lower directions respectively.

[0031] like Figure 5 As shown, the upper air outlet 10 is provided with an upper air outlet wind shield 10.3, one end of the upper air outlet wind shield 10.3 is connected to the upper air outlet baffle tractor 10.4, the upper air outlet baffle tractor 10.4 is connected to the upper air outlet baffle adjustment knob 10.1, and the upper air outlet baffle tractor 10.4 is driven by rotating the upper air outlet baffle adjustment knob 10.1, and the traction function of the tractor is used to adjust the rotation angle of the upper air outlet wind shield 10.3. The upper air outlet 10 is provided with an upper air outlet grille 10.2, and the deflection angle of the upper air outlet grille 10.2 is adjusted by the upper air outlet grille adjustment knob 10.5.

[0032] like Figure 5 As shown, the lower air outlet 11 is provided with a lower air outlet wind shield 11.3, one end of the lower air outlet wind shield 11.3 is connected to the lower air outlet baffle tractor 11.4, and the lower air outlet baffle tractor 11.4 is connected to the lower air outlet baffle adjustment knob 11.1. The lower air outlet baffle tractor 11.4 is driven by rotating the lower air outlet baffle adjustment knob 11.1, and the traction function of the tractor is used to adjust the rotation angle of the lower air outlet wind shield 11.3. The lower air outlet 11 is provided with a lower air outlet grille 11.2, and the deflection angle of the lower air outlet grille 11.2 is adjusted by the lower air outlet grille adjustment knob 11.5.

[0033] like Figure 4 As shown, two adjacent main air ducts 9 are connected through a four-way valve 12, and the four-way valve 12 is provided with a first connecting port 12.3, a second connecting port 12.4, a third connecting port 12.5 and a fourth connecting port 12.6. The first connecting port 12.3 and the second connecting port 12.4 are used to connect the front and rear sections of the main air duct 9, the third connecting port 12.5 is closed or used to connect the wind curtain generating device at the air inlet corner, and the fourth connecting port 12.6 is connected to the compressed air pipeline. The upper and lower ends of the four-way valve are provided with upper and lower air outlet strips of fixed width, which are used to communicate with the upper air outlet 10 and the lower air outlet 11 respectively.

[0034] The first connecting port 12.3 and the second connecting port 12.4 are used to connect the front and rear sections of the wind curtain generating device, the third connecting port 12.5 is used to connect the wind inlet corner wind curtain generating device 5, and the fourth connecting port 12.6 is connected to the compressed air pipeline 6. An upper air outlet strip 12.1 and a lower air outlet strip 12.2 of fixed width are provided at the upper and lower ends of the four-way valve 12. The main air duct is provided with an upper air outlet 10 and a lower air outlet 11. An upper air outlet grille 10.2 and a lower air outlet grille 11.2 of the same length as the air duct are installed inside the air outlet, and the angles can be adjusted by the upper air outlet grille adjustment knob 10.5 and the lower air outlet grille adjustment knob 11.5 respectively. The upper air outlet wind shield 10.3 and the lower air outlet wind shield 11.3 are installed at the air outlet position of the main air duct 9, and the width of the wind shield covers the width of the air outlet of the main air duct 9 as a whole. An upper air outlet baffle adjusting knob 10.5 and a lower air outlet baffle adjusting knob 11.5 as well as an upper air outlet baffle tractor 10.4 and a lower air outlet baffle tractor 11.4 connected thereto are installed on one side of the two air outlet wind shields.

[0035] By turning the upper and lower air outlet baffle adjustment knobs 10.1 and 11.1, the baffle puller's pull angle is adjusted, thereby varying the area of ​​the air outlet covered by the wind deflector, allowing for adjustments to the air volume and speed at the air curtain's outlet. By turning the upper and lower air outlet grille adjustment knobs 10.5 and 11.5, the offset angles of the air outlet grilles at each end of the device are adjusted to control the airflow direction. This creates an air curtain wall at the upper and lower ends of the main duct, allowing for flexible adjustment of parameters such as the jet angle, outlet width, and air velocity.

[0036] A method for using a flexible leak-proof device for a wind curtain wall in a goaf area with a top-cut goaf-retaining entry includes the following steps:

[0037] A compressed air pipeline 6 is installed in the transport chute (the air inlet side gob retention lane) 1 and the track chute 2. The compressed air pipeline 6 has radial communication ports at regular intervals, connected to the fourth communication port 12.6 of the four-way valve 12. The radial communication ports of the compressed air pipeline 6 are closed when not connected to the four-way valve 12.

[0038] S100: After the mining working face is formed, a plurality of sections of wind curtain generating devices are arranged in parallel to the compressed air pipeline 6 in the transport chute (the goaf-retained lane along the air inlet side) 1 at a certain distance from the wall of the goaf. Each section of the wind curtain generating device is connected to the first connecting port 12.3 and the second connecting port 12.4 of the four-way valve and fixed by a metal bracket. The fourth connecting port 12.6 of the four-way valve is connected to the radial connecting port of the compressed air pipeline, and the other unconnected pipe ports are closed. A wind curtain generating device with a length equal to the width of the lane is installed at the air inlet corner. This section of the wind curtain generating device is connected to the third connecting port 12.5 of the four-way valve, and the wind curtain generating device is fixed by a metal bracket.

[0039] S200: After the work surface begins, air is supplied to the air curtain generator. During operation, the upper air outlet baffle adjustment knob 10.1 and the lower air outlet baffle adjustment knob 11.1 are rotated to adjust the baffle puller's traction angle, thereby changing the area of ​​the air outlet covered by the wind baffle, thereby adjusting the air volume and wind speed at the air curtain generator's outlet. The offset angle of the air outlet grilles at both ends of the device is adjusted by rotating the upper air outlet grille adjustment knob 10.5 and the lower air outlet grille adjustment knob 11.5 to control the airflow direction.

[0040] S300: After the working face advances a certain distance, the air curtain generating device originally located at the air inlet side gob retention and the air inlet corner 7 is removed, and the third connecting port 12.5 of the four-way valve 12 connected thereto is closed. The removed air curtain generating device is connected to the third connecting port 12.5 of the next four-way valve 12, and this cycle is repeated. As the working face advances forward, the goaf area gradually expands, and the gob retention on the return air side gradually takes shape. While the air curtain generating device 13 on the air inlet side is recovered, air curtain generating devices are gradually deployed along the gob retention 3 on the return air side, and the arrangement method is the same as that of the gob retention on the air inlet side.

[0041] S400: As the working face of cutting the top and retaining the tunnel along the goaf continues to advance, the wind curtain wall at the air inlet corner gradually moves forward, the wind curtain wall along the tunnel retaining along the air inlet side gradually shortens, and the wind curtain wall along the tunnel retaining along the return air side gradually lengthens until the entire working face is completed.

[0042] S500: When the working face is mined, all the air curtain generators along the gob-side entry on the air inlet side are recovered, and the air curtain generators along the gob-side entry on the return air side are deployed. When the next working face is mined, the gob-side entry on the return air side of the previous working face becomes the gob-side entry on the air inlet side of the new mining face, and this cycle repeats.

[0043] The present invention proposes to arrange a compressed air duct network along the transport drift and track drift of the cut-top goaf working face, and arrange a wind curtain wall generating device at a certain distance from the wall of the goaf area at the interval of the air inlet corner, the air inlet side goaf and the return air side goaf, and at a position slightly below the roof. The compressed air in the compressed air duct network is used as the energy source, and a plane jet wind curtain wall is generated by the wind curtain wall generating device suspended on the air leakage path. The resistance-increasing and pressure-increasing effect of the wind curtain wall is used to isolate the air leakage flow field in the goaf area of ​​the cut-top goaf. As the cut-top goaf working face continues to advance, the wind curtain wall at the air inlet corner gradually moves forward, the wind curtain wall along the air inlet side goaf gradually shortens, and the wind curtain wall along the return air side goaf gradually lengthens. The wind curtain wall jet angle, outlet width, and outlet speed are flexibly adjusted according to the direction and size of the air leakage. After the cut-top goaf working face is advanced, the air supply to the wind curtain wall generating device is stopped and recovered. The present invention achieves the dual effects of equalizing pressure plugging and spraying plugging, and has the significant advantages of good plugging effect, no pollution, no impact on working face production and personnel passage. It can effectively control air leakage in the goaf of the top cutting and goaf-side tunnel retention area, and prevent the occurrence of gas and natural fire disasters in the goaf.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A flexible leak-proof device for the wind curtain wall of a goaf with a top-cut goaf-retaining entry, characterized by: The system comprises compressed air pipelines arranged in the transport chute and the track chute, and wind curtain wall generating devices arranged at a certain distance from the wall of the goaf and slightly below the roof in the air inlet corner, the transport chute and the return air side goaf retaining lane. The wind curtain wall generating devices are connected to the compressed air pipelines, which are supplied with compressed air. The wind curtain wall generating devices generate a plane jet wind curtain wall, which utilizes the resistance-increasing and pressure-increasing effects of the wind curtain wall to isolate the air leakage flow field in the goaf of the goaf retaining lane along the cut roof. The wind curtain wall generating device comprises a plurality of main body wind tubes connected in sequence, wherein an upper air outlet is provided on the upper side of the main body wind tube and a lower air outlet is provided on the lower side of the main body wind tube, and the upper air outlet and the lower air outlet spray the wind curtain in the upper and lower directions respectively; The upper air outlet is provided with an upper air outlet wind shield, one end of the upper air outlet wind shield is connected to the upper air outlet baffle tractor, the upper air outlet baffle tractor is connected to the upper air outlet baffle adjustment knob, the upper air outlet baffle tractor is driven by rotating the upper air outlet baffle adjustment knob, and the traction function of the tractor is used to adjust the rotation angle of the upper air outlet wind shield. The upper air outlet is provided with an upper air outlet grille, and the deflection angle of the upper air outlet grille is adjusted by the upper air outlet grille adjustment knob; The lower air outlet is provided with a lower air outlet wind shield, one end of the lower air outlet wind shield is connected to the lower air outlet baffle puller, the lower air outlet baffle puller is connected to the lower air outlet baffle adjustment knob, the lower air outlet baffle puller is driven by rotating the lower air outlet baffle adjustment knob, and the traction function of the tractor is used to adjust the rotation angle of the lower air outlet wind shield. The lower air outlet is provided with a lower air outlet grille, and the deflection angle of the lower air outlet grille is adjusted by the lower air outlet grille adjustment knob. Two adjacent main air ducts are connected by a four-way valve, and the four-way valve is provided with a first connecting port, a second connecting port, a third connecting port and a fourth connecting port. The first connecting port and the second connecting port are used to connect the front and rear sections of the main air ducts, the third connecting port is closed or used to connect the wind curtain generating device at the air inlet corner, and the fourth connecting port is connected to the compressed air pipeline. The upper and lower ends of the four-way valve are provided with upper and lower air outlet strips of fixed width, which are used to connect with the upper air outlet and the lower air outlet respectively.

2. A method for using the flexible leak-proof device for goaf-side entry retention with a roof cut as claimed in claim 1, characterized in that: The following steps are included: S100: After the mining face is formed, a multi-section air curtain generator is arranged in parallel with the compressed air pipeline in the transport chute at a certain distance from the wall of the goaf; an air curtain generator with a length equal to the width of the roadway is installed at the air inlet corner and fixed with a metal bracket; S200: After the working face starts working, air is supplied to the air curtain generating device, and the air volume, wind speed and air flow direction of the air curtain generating device outlet are adjusted; S300: As the working face advances, the goaf area gradually expands, and the goaf-side lane gradually takes shape. While the air curtain generators in the transport chute are recovered, they are gradually deployed along the goaf-side lane on the return air side. The arrangement is the same as that of the goaf-side lane on the intake air side. S400: As the working face continues to advance, the wind curtain wall at the air inlet corner gradually moves forward, the wind curtain wall of the transport chute gradually shortens, and the wind curtain wall along the return air side of the gob is gradually extended until the entire working face is completed; S500: When the working face is mined, all the air curtain generating devices of the transport chute are recovered, and the air curtain generating devices of the return air side goaf are arranged; when the next working face is mined, the goaf of the return air side of the previous working face becomes the goaf of the inlet air side of the new mining working face, and the cycle repeats.

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