Dust purification method and system for air return crossheading of fully mechanized coal mining face

Abstract

The invention belongs to the technical field of coal mine fully mechanized coal mining face dust treatment. The system comprises two groups of dust control and removal devices which are arranged at intervals in the air flow direction, and each group comprises an air control device, a dust removal system, a crawler and a spraying frame. The air control device adopts a supporting frame shaped like a Chinese character'mu ', a fixed dust catching door and a movable dust catching door, and is provided with an antistatic flame-retardant flexible sealing device, and more than 87% of dust-containing airflow is guided into the dust remover. The dust removal system efficiently purifies through an air suction cover, a silencer and a dust remover, purified air on the front side is discharged through an air duct, and purified air on the rear side is directly discharged. The spraying frame is matched with the dust catching door to reduce residual dust, water consumption and roadway humidity. The crawler support system moves along with the pushing and mining of the working face, and is dynamically adjusted at an interval of 15-25m. According to the system, the concentration of respirable dust is reduced to 3.17 mg / m < 3 > or below, the total dust concentration is reduced to 7.62 mg / m < 3 > or below, the dust falling efficiency reaches 92% or above, the dust falling efficiency reaches 95% or above, and the purification efficiency, safety and working condition adaptability are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of dust control in fully-mechanized mining working faces of coal mines, and in particular to a method and system for purifying dust in a return air chute of a fully-mechanized mining working face, which is suitable for efficient control and purification of dust in a return air chute in an underground coal mine. Background Art

[0002] With the rapid development of comprehensive mechanized coal mining technology in coal mines, the production efficiency of fully mechanized mining faces has been significantly improved, but the resulting dust problem has become a major factor restricting production safety and workers' health. The return air chute is an important channel in the ventilation system of the fully mechanized mining face, carrying the task of discharging dust-laden airflow. Its dust concentration usually far exceeds the national standard (the respirable dust concentration limit is 4mg / m 3 , total dust concentration limit is 8mg / m 3 High dust concentrations not only pose a health threat to workers, increasing the risk of occupational diseases such as pneumoconiosis, but can also cause explosions due to dust deposition, seriously impacting mine safety. Furthermore, dust diffusion reduces visibility in tunnels, impacting operational efficiency and equipment stability. Therefore, the development of efficient return air chute dust purification technology is an urgent need for safe coal mine production.

[0003] In the existing technology, dust control in the return air chute mainly relies on the following methods: spray dust reduction, ventilation dust control and wet dust removal. Spray dust reduction uses a spray device in the tunnel to capture dust particles with water mist, which is simple to operate and low in cost. However, this method has a low capture efficiency for fine respirable dust (particle size less than 5μm), usually only 60%-70%, and the spraying process can easily lead to excessive humidity in the tunnel, affecting the working environment and equipment operation, and even causing the ground to be slippery, increasing safety hazards. Ventilation dust control attempts to reduce dust diffusion by adjusting the ventilation system to guide the dust-laden airflow to a specific area, but is limited by the complex tunnel structure of the return air chute and the difficulty of adjusting the air volume. It is difficult to effectively concentrate the dust to the purification equipment, resulting in some dust spreading to other areas of the tunnel with the wind flow, and the purification effect is not ideal. Wet dust removal uses a wet dust collector to capture dust through a water film or water mist, which has a high purification efficiency. However, traditional wet dust collectors are usually single fixed installations with limited air volume, making it difficult to cope with high air volume (usually 2000m3) in fully mechanized mining working faces. 3 / min or more) and high dust concentration (up to 300mg / m 3 In working conditions (above), the purification efficiency is generally between 70% and 80%. In addition, fixed dust removal equipment cannot be dynamically adjusted with the working surface, requiring frequent disassembly and assembly, resulting in low construction efficiency and difficulty in meeting production needs.

[0004] In terms of wind control devices, existing technologies often use dust-catching nets or wind curtains to guide the wind flow, but these devices have obvious defects. Dust-catching nets are usually made of ordinary fiber materials, have poor sealing properties, are prone to aging and damage, and are complicated to install and disassemble. They are difficult to adapt to the tunnel anchor net structure, resulting in serious air leakage and low dust collection efficiency. Although wind curtains are easy to install, they lack wind pressure resistance and are easily deformed or torn under high wind volume conditions, affecting the dust control effect. In addition, most existing dust control devices are fixed and lack mobility. They cannot adapt to changes in tunnel position during the mining process of the comprehensive mining face, which limits the flexibility and practicality of the system.

[0005] In summary, existing return air chute dust control technologies have the following common problems: 1) A single dust collector handles insufficient air volume, making it difficult to cope with complex working conditions with high air volume and high dust concentration, resulting in low purification efficiency; 2) Dust collection devices have poor sealing, resulting in air leakage and severe dust dispersion; 3) The humidity of the spray dust suppression system is too high, affecting the roadway environment and operational safety; 4) The system is fixed and difficult to move, making it difficult to adapt to the dynamic needs of face mining. These problems make it difficult for existing technologies to meet the strict national requirements for dust concentration and effectively protect the health of workers and mine safety. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to solve the problem of dust purification in the return air chute of the comprehensive mining working face, and propose a dust purification method and system for the return air chute of the comprehensive mining working face. Through the segmented air and dust control structure, efficient dust purification is achieved, the concentration of respirable dust and total dust is reduced, and the dynamic needs of mining on the working face are adapted. At the same time, the humidity is reduced and the safety of the working environment is improved.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A dust purification system for a return air chute of a fully mechanized mining face comprises two dust control and removal devices arranged in a front-to-rear spacing along the airflow direction, wherein the dust control and removal devices comprise an air control device, a dust removal system, a crawler vehicle and a spray rack;

[0009] The wind control device is arranged on the windward side of the crawler vehicle, and includes a support frame, a movable dust collecting door, and a fixed dust collecting door; the fixed dust collecting door is installed in the middle of the support frame, the movable dust collecting door is installed on one side of the fixed dust collecting door, and the other side is the air inlet of the dust collector; the spray frame is installed on the support frame to provide water mist to the movable dust collecting door and the fixed dust collecting door for dust collection;

[0010] The dust removal system is provided on the crawler vehicle and includes a dust collector, an air suction hood, and a muffler; one end of the air suction hood is connected to the air inlet of the dust collector, and the other end is connected to the dust collector through the muffler;

[0011] The air outlet of the dust collector of the dust control device located at the front side is connected to the air duct through a wind guiding device and a conversion joint, and the air outlet of the dust collector of the dust control device located at the rear side directly discharges the purified air flow backward.

[0012] Furthermore, the air control devices in the two dust control devices are both arranged perpendicular to the air flow direction.

[0013] Furthermore, the support frame includes left-side columns, right-side columns, upper cross beams, lower cross beams and middle columns. The left-side columns and right-side columns are respectively connected to the upper cross beams and lower cross beams, and the upper cross beam and the lower cross beam are connected by two middle columns to form a "mu" character structure. Flexible sealing devices are arranged around the "mu" character structure.

[0014] Furthermore, the left-side columns and right-side columns are symmetrically arranged. Each column includes a column main body, inclined supports and a bottom plate. The column main body is welded to the bottom plate and two inclined supports to form a triangular stable structure. Universal wheels are installed on the bottom plate, and chain links are welded on the column main body. The chain links are connected to the roadway anchor net through iron chains to prevent the air control device from tipping over.

[0015] Furthermore, the flexible sealing device is made of antistatic and flame-retardant flexible air duct cloth. The inner side is connected to the left-side columns, right-side columns, upper cross beams and lower cross beams by bolts, and strong magnets are arranged on the outer side or fixed to the roadway anchor net through binding wires.

[0016] Furthermore, the fixed dust-catching door includes a door frame, a stainless steel wire mesh and a wind baffle. The door frame is a "square" character structure, and a "feng" character flat iron is welded inside. The stainless steel wire mesh is a 20-mesh, 3-layer overlapping structure and is fixed to the door frame by riveting. The wind baffle is welded to the leeward side of the door frame and strong magnets are arranged, which lap with the movable dust-catching door.

[0017] Furthermore, the movable dust-catching door includes a door frame, a stainless steel wire mesh and a handle. The door frame is connected to the right-side column through a hinge. The stainless steel wire mesh is a 20-mesh, 3-layer overlapping structure and is fixed to the door frame by riveting.

[0018] Furthermore, a support device is arranged at the bottom of the lower cross beam. The support device is in a "cross" character structure, is connected to the lower cross beam by bolts, and high-strength studs are arranged at the bottom. The ground is tightened by rotating the studs to support the air control device.

[0019] Furthermore, the air suction hood is a foldable structure, and the air inlet area is increased by unfolding.

[0020] Furthermore, the crawler vehicle includes a crawler vehicle chassis, a hydraulic system, a vacuum electromagnetic starter for crawler vehicle and a crawler vehicle operation valve. The hydraulic system controls the movement of the crawler vehicle chassis through the crawler vehicle operation valve. The vacuum electromagnetic starter for crawler vehicle is arranged above the crawler vehicle chassis and is used to start the hydraulic system.

[0021] Furthermore, the spray rack is connected to the return air chute water supply pipeline through a high-pressure hose, and the width of the spray rack is equal to the sum of the widths of the movable dust collecting door and the fixed dust collecting door.

[0022] A method for purifying dust in a return air chute of a fully mechanized mining face comprises the following steps:

[0023] (1) The dust purification system for the return air chute of a fully mechanized mining face according to claim 1 is used in the return air chute, and two groups of dust control and removal devices are arranged in a front-to-back interval along the air flow direction, each group of dust control and removal devices includes an air control device, a dust removal system, a crawler vehicle and a spray rack;

[0024] (2) The dust-laden airflow passes through the front air control device, and most of the airflow enters the dust collector in the front dust removal system through the air suction hood for purification. The purified airflow is discharged through the air guide device, the conversion joint and the air duct; the remaining dust-laden airflow passes through the fixed dust collection door and the movable dust collection door of the front air control device, enters the rear air control device, is purified by the dust collector in the rear dust removal system and is discharged from the air outlet. At the same time, spray is sprayed in front of the rear air control device through the spray rack to reduce dust on the airflow that has not entered the dust removal system;

[0025] (3) As the working face is mined, the two sets of dust control and removal devices are regularly moved forward to a range of 50 to 100 meters from the working face by crawler vehicles.

[0026] Furthermore, the rated air volume of the dust collectors in the two sets of dust control devices is greater than half of the air supply volume of the working surface, to ensure that most of the dust-laden airflow enters the dust removal system for purification, while ensuring that the wind speed in the tunnel where the rear dust removal system is located is not less than 0.15m / s.

[0027] Furthermore, the spacing between the two groups of dust control and removal devices is dynamically adjusted according to the return air chute air volume and dust concentration, with a spacing range of 15 to 25 meters to optimize the diversion and purification effects.

[0028] The beneficial effects of the present invention are:

[0029] 1. High dust purification capacity: In this invention, two sets of dust control and removal devices are arranged at intervals along the air flow direction, forming a sectional and wind-controlled dust removal structure, following the treatment ideas of "diverting air flow", "concentrating air flow", and "removing dust". The rated air handling capacity of each dust collector is greater than half of the air supply volume of the working face, ensuring that it can handle the high-air-volume and dust-laden air flow in the return air heading. The fixed dust-catching door and the movable dust-catching door are designed with 20-mesh and 3-layer stainless steel wire meshes, which can guide more than 87% of the dust-laden air flow to enter the dust collector through the air suction hood. The front dust control and removal device discharges the purified air flow through the air guiding device, the adapter, and the air duct, while the rear dust control and removal device directly discharges the purified air flow, achieving the full and effective purification of the polluted air in the fully mechanized mining face. Compared with the traditional single wet dust collector (with limited air handling capacity) or spray dust suppression (low efficiency for respirable dust), the coordinated operation of the two dust collectors and the efficient dust-catching door design in this invention significantly improve the purification efficiency. After the polluted air is treated, the respirable dust concentration in the return air heading of the fully mechanized mining face is reduced to 3.17 mg / m 3 Below, the total dust concentration is reduced to 7.62 mg / m 3 Below, the average dust reduction efficiencies of the total dust and respirable dust respectively reach over 95% and 92%, which is especially suitable for the complex working conditions of high air volume and high dust concentration in the return air heading.

[0030] 2. Excellent air control efficiency and sealing performance: The air control device in this invention adopts a "mesh" - shaped support frame, which is arranged perpendicular to the air flow direction to maximize the guidance of the dust-laden air flow into the air inlet of the dust collector. The frame is bolted together by the left column, the right column, the upper cross beam, the lower cross beam, and the middle column, and is equipped with an anti-static and flame-retardant flexible sealing device. It is bolted on the inner side and fixed to the roadway anchor net by strong magnets or binding wires on the outer side, effectively reducing air leakage. The fixed dust-catching door overlaps with the movable dust-catching door through the wind baffle and strong magnets, further enhancing the sealing performance. The combined action of the air control device and the spray rack can effectively purify the remaining polluted air that has not entered the dust collector. Compared with the traditional dust-catching net (poor sealing performance and easy to age) or the wind curtain (insufficient wind pressure resistance), the air control device in this invention significantly improves the air control efficiency and sealing performance, reducing dust diffusion.

[0031] 3. Reduction of spray water consumption and roadway humidity: The spray rack in this invention is connected to the water supply pipeline of the return air heading through a high-pressure rubber hose. Its width is the same as that of the dust-catching door, and it supports spray pressure adjustment. It can effectively capture the remaining dust that has not entered the dust removal system, while significantly reducing the spray water consumption. The spray in front of the air control device and the air control device work together to reduce the fog residue. Compared with the traditional spray dust suppression (high humidity and limited visibility), this invention effectively reduces the roadway humidity, improves the visibility clarity and the working environment, and avoids problems such as slippery ground and equipment corrosion.

[0032] 4. Flexible mobility and adaptability to working conditions: The crawler vehicle in the present invention is equipped with a crawler chassis, a hydraulic system, a vacuum electromagnetic starter and an operating valve, which supports the rapid movement of the dust removal control device in the return air chute, and is adjusted to a range of 50-100m from the working face as the working face is pushed and mined. The column base plate is equipped with universal wheels for easy fine-tuning to adapt to complex tunnel environments. The interval between the two sets of dust removal devices can be dynamically adjusted (15-25m), and the diversion effect can be optimized according to the air volume and dust concentration. Compared with traditional fixed equipment (which requires frequent disassembly and assembly), the mobile design of the present invention improves construction efficiency and production continuity.

[0033] Other advantages, objects, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0035] Figure 1 It is an overall schematic diagram of the return air chute and wind control and dust removal system of the fully mechanized mining working face in the present invention.

[0036] Figure 2 It is a structural schematic diagram of the wind control device in the present invention.

[0037] Figure 3 It is a schematic structural diagram of the left column of the wind control device of the present invention.

[0038] Figure 4 This is a schematic diagram of the structure of the fixed dust collecting door of the wind control device in the present invention.

[0039] Figure 5 This is a schematic diagram of the structure of the movable dust-collecting door of the wind control device of the present invention.

[0040] Figure 6 for Figure 5 side view.

[0041] Figure 7 Schematic diagram of the suction hood structure of the dust removal system in the present invention.

[0042] Figure 8 It is a schematic diagram of the arrangement of the crawler vehicle in the present invention.

[0043] Figure 9 for Figure 8 Top view of .

[0044] Figure markings: 1-wind control device; 11-left column; 12-right column; 13-upper crossbeam; 14-lower crossbeam; 15-middle column; 16-movable dust collection door; 161-door frame; 162-stainless steel wire mesh; 163-handle; 17-fixed dust collection door; 171-door frame; 172-stainless steel wire mesh; 173-wind deflector; 18-flexible sealing device; 19-support device; 2-dust removal system; 21-air suction hood; 22-muffler; 23-dust collector; 24-air guide device; 25-conversion joint; 26-air duct; 27-vacuum electromagnetic starter for dust collector; 3-tracked vehicle; 31-tracked chassis; 32-hydraulic system; 33-vacuum electromagnetic starter for tracked vehicle; 34-tracked vehicle operating valve; 4-spray rack. DETAILED DESCRIPTION

[0045] The following describes the embodiments of the present invention by means of specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0046] Among them, the accompanying drawings are only for illustrative purposes and represent only schematic diagrams rather than actual pictures, and should not be understood as limiting the present invention. In order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the dimensions of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the accompanying drawings.

[0047] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "back", etc. indicating directions or positional relationships, they are based on the directions or positional relationships shown in the drawings. 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 direction, be constructed and operate in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0048] Example 1

[0049] See also Figures 1 to 9, it is a dust purification system for the return air heading of a fully mechanized mining face, including a first group of dust control and removal devices (front side) and a second group of dust control and removal devices (rear side) arranged at intervals of 20 m along the air flow direction. Each group of dust control and removal devices includes an air control device 1, a dust removal system 2, a crawler vehicle 3 and a spray rack 4.

[0050] The air control device 1 is installed on the windward side of the crawler vehicle 3 and is arranged perpendicular to the air flow direction. It includes a support frame, a fixed dust capture door 17 and a movable dust capture door 16. The support frame is formed by connecting the left side column 11, the right side column 12, the upper cross beam 13, the lower cross beam 14 and two middle columns 15 with bolts to form a "mu" shaped structure, and antistatic and flame retardant flexible sealing devices 18 are arranged around. The flexible sealing device 18 is made of antistatic and flame retardant flexible air duct cloth, the inner side is connected to the columns and cross beams by bolts, and the outer side is fixed to the roadway anchor net by strong magnets or binding wires to reduce air flow leakage.

[0051] The left side column 11 and the right side column 12 are symmetrically arranged. Each column is formed by welding a column main body, an inclined support and a bottom plate to form a triangular stable structure. The bottom plate is installed with universal wheels for easy fine adjustment, and a link is welded on the column main body and connected to the roadway anchor net by an iron chain for easy fixation. A "cross" shaped support device 19 is arranged at the bottom of the lower cross beam 14 and is connected by bolts. The high-strength studs at the bottom rotate and press tightly against the ground to support the air control device.

[0052] The fixed dust capture door 17 includes a door frame 171, a stainless steel wire mesh 172 and a wind baffle 173. The door frame 171 is a "square" shaped structure, with a "feng" shaped flat iron welded inside. The stainless steel wire mesh 172 is a 20-mesh, 3-layer overlapping structure and is fixed to the door frame by riveting. The wind baffle 173 is welded on the leeward side and equipped with strong magnets to overlap with the movable dust capture door 16 to ensure airtightness.

[0053] The movable dust capture door 16 includes a door frame 161, a stainless steel wire mesh 162 and a handle 163. The door frame 161 is connected to the right side column 12 by a hinge. The stainless steel wire mesh 162 is a 20-mesh, 3-layer overlapping structure and is fixed by riveting. The handle 163 is welded on both the inside and outside of the left side of the door frame 161, and the distance from the ground is about 1.3 m for easy opening and closing.

[0054] The dust removal system 2 is installed on the crawler vehicle 3 and includes a dust collector 23, a foldable air suction hood 21 and a silencer 22. One end of the air suction hood 21 is connected to the air inlet of the dust collector, and the other end is connected to the dust collector 23 through the silencer 22. The foldable structure supports adjusting the area of the air inlet. The air outlet of the dust collector of the first group of dust control and removal devices is connected to the air duct 26 through a wind guiding device 24 and a conversion joint 25 to discharge the purified air flow. The air outlet of the second group of dust control and removal devices directly discharges the purified air flow. The dust collector 23 is equipped with a vacuum electromagnetic starter 27 for dust collector to control the operation.

[0055] The crawler vehicle 3 includes a chassis 31, a hydraulic system 32, a crawler vehicle vacuum electromagnetic starter 33, and a crawler vehicle operating valve 34. The hydraulic system 32 controls the movement of the chassis 31 through the crawler vehicle operating valve 34. The crawler vehicle vacuum electromagnetic starter 33 is located above the chassis 31 and activates the hydraulic system.

[0056] The spray rack 4 is connected to the return air chute water supply pipeline through a high-pressure hose. Its width is equal to the sum of the widths of the fixed dust collecting door 17 and the movable dust collecting door 16. It supports spray pressure adjustment and provides water mist for dust suppression for the dust collecting door.

[0057] Example 2

[0058] like Figures 1 to 9 As shown, a dust purification method using the above system is shown, in which the system in Example 1 is applied to the return air chute of a fully mechanized mining face in a coal mine, comprising the following steps:

[0059] (1) Arrange the first set of dust control and removal devices (front side) and the second set of dust control and removal devices (rear side) in the return air duct along the airflow direction, with an interval of 20m. Each set of dust control and removal devices includes an air control device 1, a dust removal system 2, a crawler 3, and a spray rack 4.

[0060] (2) The dust-laden airflow passes through the first set of wind control devices, and more than 87% of the airflow is guided through a 20-mesh, 3-layer stainless steel wire mesh dust collection door, and enters the dust collector 23 for purification through a foldable suction hood 21 and a muffler 22. The purified airflow is discharged through an air guide device 24, a conversion joint 25, and a wind tube 26.

[0061] The remaining dust-laden airflow passes through the fixed dust collecting door 17 and the movable dust collecting door 16 of the first set of air control devices, enters the second set of air control devices, is purified by the air suction hood 21, the muffler 22 and the dust collector 23, and is directly discharged from the air outlet.

[0062] At the same time, in front of the second set of wind control devices, spray dust is reduced through the spray rack 4. The spray pressure is adjusted by a high-pressure hose and works together with the wind control device to capture the remaining dust that has not entered the dust removal system and reduce the residual mist.

[0063] (3) As the working face is mined, when the distance between the system and the working face is less than 50m, the hydraulic system 32 and the operating valve 34 are operated by the crawler vehicle 3 to move the two sets of dust removal devices forward to a range of 50-100m.

[0064] Among them, the rated processing air volume of each group of dust collectors is greater than half of the air supply volume of the working surface, and the spacing can be adjusted to 15-25m according to the air volume and dust concentration to optimize the diversion and purification effects.

[0065] The dust purification principle is as follows:

[0066] The return air chute has a high air volume, fully dispersed dust, and a high proportion of respirable dust. To address this situation, this embodiment employs a strategy of "diverging," "concentrating," and "removing" to control dust in the return air chute. Given the high air volume in the return air chute, two dust collectors 23, arranged in a tandem arrangement, provide purification. To fully purify the polluted air from the work surface, the two dust collectors 23 are spaced 20 meters apart. First, the dust-laden airflow from the return chute passes through the first air control device 1, where it is split into two parts. The dust collector 23 selected for dust removal system 2 must have a rated handling capacity greater than half the air volume supplied to the work surface. Therefore, due to the "wind gathering" effect of air control device 1, the majority of the airflow will flow through the opening on the left side of air control device 1. At this point, part of the airflow will pass through the suction hood 21, muffler 22, and the front dust collector 23 for purification, before passing through the air guide 24, adapter 25, and air duct 26 and being discharged from the air outlet of air duct 26. The remaining dust-laden airflow, after passing through air control device 1, is almost entirely concentrated by the second air control device 1, passing through the rear suction hood 21, muffler 22, and the rear dust collector 23 for purification, before being discharged from the dust collector 23 exhaust port. The polluted air that does not pass through the rear dust collector 23 will also be purified by the spray at the front top of the second air control device 1 in combination with it.

[0067] Through the treatment of this system, the respirable dust concentration in the return air chute of the fully mechanized mining face can be reduced to 3.17mg / m 3 Below, the total dust concentration can be reduced to 7.62mg / m 3 The average dust reduction efficiency of total dust and respirable dust can reach 95% and 92% respectively, the dust concentration in the tunnel is significantly reduced, and the air humidity is significantly lower than when a large amount of spray is used. The field of view of the return air chute is clear and the working environment is significantly improved.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions, which should all be included in the scope of the claims of the present invention.

Claims

1. A dust purification system for return air chute of fully mechanized mining working face, characterized by: It includes two dust control and removal devices arranged at intervals before and after in the air flow direction. The dust control and removal device includes a wind control device, a dust removal system, a crawler vehicle and a spray rack; The wind control device is arranged on the windward side of the crawler vehicle. The wind control device includes a support frame, a movable dust-catching door and a fixed dust-catching door; The fixed dust-catching door is installed in the middle of the support frame. A movable dust-catching door is installed on one side of the fixed dust-catching door, and the other side is the air inlet of the dust collector; The spray rack is arranged on the support frame to provide water mist for the movable dust-catching door and the fixed dust-catching door to catch dust; The dust removal system is arranged on the crawler vehicle. The dust removal system includes a dust collector, a suction hood and a silencer; One end of the suction hood is connected to the air inlet of the dust collector, and the other end is connected to the dust collector through a silencer; The air outlet of the dust collector of the dust control and removal device located at the front side is connected to the air duct through a wind guiding device and a conversion joint, and the air outlet of the dust collector of the dust control and removal device located at the rear side directly discharges the purified air flow backward.

2. The dust purification system for return air chute of fully mechanized mining working face according to claim 1 is characterized by: The wind control devices in the two dust control and removal devices are both arranged perpendicular to the air flow direction.

3. The dust purification system for return air chute of fully mechanized mining working face according to claim 1 is characterized by: The support frame includes a left column, a right column, an upper cross beam, a lower cross beam and a middle column. The left column and the right column are respectively connected to the upper cross beam and the lower cross beam. The upper cross beam and the lower cross beam are connected by two middle columns to form a "mu" shaped structure, and a flexible sealing device is arranged around the "mu" shaped structure.

4. The dust purification system for return air chute of fully mechanized mining working face according to claim 3 is characterized by: The left column and the right column are symmetrically arranged. Each column includes a column main body, an inclined support and a bottom plate. The column main body is welded to the bottom plate and two inclined supports to form a triangular stable structure. Universal wheels are installed on the bottom plate, and a chain link is welded on the column main body. The chain link is connected to the roadway anchor net through an iron chain to prevent the wind control device from tipping over.

5. The dust purification system for return air chute of fully mechanized mining working face according to claim 3 is characterized by: The flexible sealing device is made of antistatic and flame-retardant flexible air duct cloth. The inner side is connected to the left column, the right column, the upper cross beam and the lower cross beam by bolts, and strong magnets are arranged on the outer side or fixed to the roadway anchor net through binding wires.

6. The dust purification system for return air chute of fully mechanized mining working face according to claim 1 is characterized by: The fixed dust-catching door includes a door frame, a stainless steel wire mesh and a wind baffle. The door frame is a "kou" shaped structure, and a "feng" shaped flat iron is welded inside. The stainless steel wire mesh is a 20-mesh, 3-layer overlapping structure and is fixed to the door frame by riveting. The wind baffle is welded to the leeward side of the door frame and is provided with strong magnets to overlap with the movable dust-catching door.

7. The dust purification system for return air chute of fully mechanized mining working face according to claim 1 is characterized by: The movable dust-catching door includes a door frame, a stainless steel wire mesh and a handle. The door frame is connected to the right column by a hinge. The stainless steel wire mesh is a 20-mesh, 3-layer overlapping structure and is fixed to the door frame by riveting.

8. The dust purification system for return air chute of fully mechanized mining working face according to claim 3 is characterized by: A support device is arranged at the bottom of the lower cross beam. The support device is in a "cross" shaped structure and is connected to the lower cross beam by bolts. High-strength studs are arranged at the bottom, and the ground is tightened by rotating the studs to support the wind control device.

9. The dust purification system for return air chute of fully mechanized mining working face according to claim 1 is characterized by: The suction hood is a foldable structure, and the air inlet area is increased by unfolding.

10. The dust purification system for return air chute of fully mechanized mining working face according to claim 1 is characterized by: The crawler vehicle includes a crawler vehicle chassis, a hydraulic system, a vacuum electromagnetic starter for the crawler vehicle and a crawler vehicle operation valve. The hydraulic system controls the movement of the crawler vehicle chassis through the crawler vehicle operation valve. The vacuum electromagnetic starter for the crawler vehicle is arranged above the crawler vehicle chassis and is used to start the hydraulic system.

11. The dust purification system for return air chute of fully mechanized mining working face according to claim 1 is characterized by: The spray rack is connected to the return air chute water supply pipeline through a high-pressure hose. The width of the spray rack is equal to the sum of the widths of the movable dust collecting door and the fixed dust collecting door.

12. A method for purifying dust in a return air chute of a fully mechanized mining face, characterized in that: The following steps are involved: (1) The dust purification system for the return air chute of a fully mechanized mining face according to any one of claims 1 to 11 is used in the return air chute, and two groups of dust control and removal devices are arranged in a front-to-back interval along the air flow direction, each group of dust control and removal devices including an air control device, a dust removal system, a crawler vehicle, and a spray rack; (2) The dust-laden airflow passes through the front air control device, and most of the airflow enters the dust collector in the front dust removal system through the air suction hood for purification. The purified airflow is discharged through the air guide device, the conversion joint and the air duct; the remaining dust-laden airflow passes through the fixed dust collection door and the movable dust collection door of the front air control device, enters the rear air control device, is purified by the dust collector in the rear dust removal system and is discharged from the air outlet. At the same time, spray is sprayed in front of the rear air control device through the spray rack to reduce dust on the airflow that has not entered the dust removal system; (3) As the working face is mined, the two sets of dust control and removal devices are regularly moved forward to a range of 50 to 100 meters from the working face by crawler vehicles.

13. The dust purification method for the return air chute of a fully mechanized mining face according to claim 12, characterized in that: The rated air volume of the dust collectors in the two sets of dust control devices is greater than half of the air supply volume of the working surface, to ensure that most of the dust-laden airflow enters the dust removal system for purification, while ensuring that the wind speed in the tunnel where the rear dust removal system is located is not less than 0.15m / s.

14. The method for purifying dust in the return air chute of a fully mechanized mining face according to claim 12, characterized in that: The spacing between the two groups of dust control and removal devices is dynamically adjusted according to the return air chute air volume and dust concentration, with a spacing range of 15 to 25 meters to optimize the diversion and purification effects.

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