Wet dust removal train device for coal mine driving face construction

Abstract

The invention discloses a wet dust removal train device for coal mine driving face construction, which comprises a front section train and a rear section train which are arranged on a track of a blind roadway and are connected in series, and a horizontal cyclone water film dust remover and an electrostatic dust remover are sequentially arranged on the front section train from front to back. An air inlet in the front end of the horizontal cyclone water film dust remover is connected with a dust collection pipeline system, an electrostatic generator and a counter-rotating axial flow fan are arranged on the left side and the right side of the rear section of train side by side correspondingly, and the front end of the electrostatic generator is connected with an electrostatic dust remover through a cable bridge; and an air outlet at the rear end of the electrostatic dust collector is connected with an air inlet at the front end of the counter-rotating axial flow fan through an air duct bridge. The device can move along with movement of the driving working face, a good dust collection state is kept, and on the premise that gas safety is ensured, the dust collection effect is greatly improved in a wet dust collection and electrostatic dust collection combined mode, and the air environment of the underground coal mine driving working face is greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of coal mine dust removal technology, specifically relating to a wet dust removal train device for coal mine tunneling face construction. Background Technology

[0002] In coal mine production, the tunneling face is one of the main dust-generating areas, with rock dust being the primary type, accounting for 20%-40% of the total dust production. Tunneling faces utilize fully mechanized tunneling or hard rock blasting techniques. The rock dust generated at the tunneling face is mainly produced by processes such as cutting, loading, crushing, and transfer. The rock dust produced at the tunneling face is primarily composed of SiO2 (silicon dust is highly hazardous), which can significantly impact worker health, equipment wear and tear, and safe production.

[0003] Coal mines typically employ techniques such as water injection to soften rock strata, spraying water, ventilation to reduce dust, and dust collection fans to suppress dust. However, current methods have limitations: dust collection fans are fixed in position and cannot be moved forward in time with the advancing working face; traditional dust suppression methods cannot reduce rock dust concentrations to the required levels; high concentrations of mine dust seriously affect workers' physical and mental health; low visibility is detrimental to safe production; high concentrations of rock dust are explosive, increasing safety risks; and they increase wear and tear on mechanical and electrical equipment, reducing its service life.

[0004] The amount of dust generated during mine production varies depending on location and time. As the level of mechanization increases at each work site, the amount of dust generated will also increase. Most coal mines in the central and eastern regions are underground mining operations, with high dust concentrations in the production environment. Coal mine dust has the following characteristics: (1) A thin film of air is adsorbed on the surface of the dust, which hinders the agglomeration and settling between dust particles or between water droplets and dust; (2) The dispersion of dust increases, and the number of oxygen molecules adsorbed on its surface increases, which accelerates the oxidation and decomposition process of dust; (3) Due to the increased surface area, the free silica in fine rock dust can easily dissolve in human lung cells; (4) Fresh dust generated at the tunneling face is more likely to become charged than dust in the return air duct.

[0005] Currently, the following measures are commonly used to reduce dust at tunneling faces: 1) Water injection softening of rock strata: The injectability of rock masses varies greatly due to factors such as whether the rock mass has sufficient fissures, the water injection pressure of the water supply pipeline, and whether the ore body has water wettability.

[0006] 2) Spraying water: Dust suppression at the working face mainly adopts a combination of internal spraying from the tunneling machine's cutting teeth and external spraying from the cutting head. Water mist dust suppression requires high spray pressure and a large spray volume. Because the ore body contains clay minerals, which are prone to mudification and expansion when exposed to water, the working face environment deteriorates. At the same time, the clay mineral dust is not effectively captured by the water spray and will have an adhesion effect, and the mineral powder often clogs the nozzles, resulting in poor dust removal effect.

[0007] 3) Ventilation and dust reduction: By strengthening ventilation, the mine dust is accelerated to flow downstream. This technology is limited by the wind speed at the working face, the negative pressure of mine ventilation, and the resistance of mine ventilation. It cannot completely solve the dust reduction problem. Moreover, this technology only dilutes and transfers the mine dust pollutants and discharges the dusty mine air into the atmosphere. It does not reliably reduce the total amount of mine dust pollutants.

[0008] 4) Dust Collector Fans: Dust collector fans reduce mine dust through the action of a power unit, dust collection unit, and collection unit. Common methods include cyclone dust collectors (poor dust removal efficiency, approximately 70%), bag filters (only suitable for dry dust collection and cannot be combined with wet spraying at the working face cutting area; the dust collection unit is prone to clogging, causing bag jamming, and has high operating resistance), and wet-blown spray dust suppressors (general dust removal effect and increased air humidity, worsening the working environment). These mechanical dust suppression methods do not provide efficient dust removal. To improve dust removal efficiency, the ventilation volume of the dust collector fan is often increased. However, increasing the fan load generates significant operating noise, which is detrimental to safe and civilized production at the working face. It also generates significant airflow disturbance, interfering with the orderly ventilation of the mine. Traditional dust collector fans are fixed in location, generally suspended by anchor cables in the return airway of the working face, and cannot be moved in time with the advancement of the working face. This causes the dust removal operation to fluctuate pulsedly, making it impossible to stabilize the dust removal process.

[0009] The aforementioned dust removal methods all suffer from technical problems of ineffectiveness and secondary dust generation: suspended mineral dust is called floating dust, while settled or collected mineral dust is called settling dust. Floating dust and settling dust can transform into each other under different conditions. When subjected to external forces, settling dust can be re-entrained and suspended in the air, resulting in secondary dust generation. Traditional dust collection fans require significant suction power, which can easily lead to improper handling of collected floating dust, resulting in secondary dust generation. Summary of the Invention

[0010] To solve the above-mentioned technical problems, the present invention provides a wet dust removal train device for coal mine tunneling face construction that has good dust removal effect, high safety and reliability, and can move with the movement of the tunneling face.

[0011] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a wet dust removal train device for coal mine tunneling face construction, comprising a front train and a rear train connected in series on the track of a single-ended roadway. A belt conveyor, a bridge transfer conveyor, and a fully mechanized tunneling machine are sequentially arranged at the front end of the front train. A horizontal cyclone water film dust collector and an electrostatic precipitator are sequentially installed on the front train from front to back. The air inlet at the front end of the horizontal cyclone water film dust collector is connected to a dust collection pipeline system. The dust collection pipeline system is equipped with a roadway floating dust collection hood, a transfer conveyor-belt conveyor dust collection hood, a tunneling machine-transfer conveyor dust collection hood, a rock loading mechanism dust collection hood, and a cutting head dust collection hood. The dust collection hoods are arranged as follows: the roadway dust collection hood is located behind the belt conveyor; the transfer conveyor-belt conveyor dust collection hood is located at the junction of the rear end and front end of the bridge transfer conveyor; the tunneling machine-transfer conveyor dust collection hood is located at the junction of the front end and rear end of the bridge transfer conveyor; the rock loading mechanism dust collection hood is located at the rear end of the rock loading mechanism of the mechanized tunneling machine; and the cutting head dust collection hood is located above and behind the cutting head of the mechanized tunneling machine. On the rear section of the train, electrostatic generators and counter-rotating axial flow fans are arranged side-by-side on the left and right. The front end of the electrostatic generator is connected to the electrostatic precipitator via a cable tray, and the air outlet at the rear end of the electrostatic precipitator is connected to the air inlet at the front end of the counter-rotating axial flow fan via a duct cable tray.

[0012] Dust collection hoods for roadways, transfer conveyors / belt conveyors, tunneling machines / transfer conveyors, rock loading mechanisms, and cutting heads all include an umbrella-shaped folding frame coaxially mounted on the suction pipe. The extension and folding of the umbrella-shaped folding frame are driven by a hollow hydraulic cylinder coaxially mounted on the suction pipe.

[0013] The horizontal cyclone water film dust collector includes a horizontally arranged outer cylinder and a dust collection water tank. The front and rear ends of the outer cylinder are equipped with blocking plates. An inner cylinder is arranged coaxially inside the outer cylinder, and a cylindrical cavity is formed between the outer circle of the inner cylinder and the inner circle of the outer cylinder. A spiral guide plate is provided between the inner cylinder and the outer cylinder to form a spiral airflow channel in the cylindrical cavity. The air inlet at the front end of the spiral airflow channel is connected to the air outlet of the dust collection pipeline system. A gas sensor is installed at the front end of the spiral airflow channel of the outer cylinder. The dust collection water tank is located below the outer cylinder and extends backward to below the electrostatic precipitator. A rectangular hole communicating with the dust collection water tank is opened along the length direction at the bottom of the outer cylinder. The water level in the dust collection water tank is inside the outer cylinder and has an air passage gap with the lowest point of the inner cylinder.

[0014] The electrostatic precipitator includes a dust collection box, which contains multiple identical sets of equipment arranged from front to back. Each set of electrostatic precipitators includes multiple dust collection plates arranged vertically along the front-to-back direction. A corona electrode is provided between any two adjacent dust collection plates. The upper ends of all the corona electrode lines are connected to a high-voltage bus terminal, which is connected to an electrostatic generator. A grounding wire is connected to the lower side of the dust collection box. The bottom of the dust collection box is open and fixedly connected to the top of the dust collection water tank. A water inlet for adding water to the dust collection water tank is provided in the middle of the rear end of the dust collection box, and a water inlet sealing plug is provided at the water inlet.

[0015] The lower part of the dust collection water tank is equipped with a mud discharge screw along the front-to-back direction. The front and rear ends of the mud discharge screw are rotatably connected to the front and rear side plates of the dust collection water tank, respectively. An explosion-proof motor reducer is provided on the outer side of the front end of the dust collection water tank. The output shaft of the explosion-proof motor reducer is connected to the front end of the mud discharge screw. A mud discharge pipe is provided on the rear side plate of the dust collection water tank below the mud discharge screw, and a mud discharge valve is provided on the mud discharge pipe.

[0016] The electrostatic generator includes an industrial frequency power input line, a regulator, an industrial frequency step-up transformer, a high-voltage rectifier, and high-voltage output terminals; the electrostatic generator is connected to an input cable tray at the rear end.

[0017] The counter-rotating axial flow fan includes a drive motor and a rigid duct arranged horizontally in the front-to-back direction. The rigid duct is equipped with a first set of counter-rotating blades and a second set of counter-rotating blades, both of which are connected to the drive motor. The front end of the rigid duct is connected to the rear end of the duct bridge. The rear end of the rigid duct is equipped with a conical airflow diffuser that is wider at the rear and narrower at the front.

[0018] Compared with the prior art, the present invention has the following advantages by adopting the above technical solution: (1) Under the action of the counter-rotating axial flow fan, the air carrying rock dust is collected by the dust collection hoods of the roadway floating dust collector, the transfer machine-belt conveyor dust collector, the tunneling machine-transfer machine dust collector, the rock loading mechanism dust collector, and the cutting head dust collector. The air then passes through the dust collection pipeline system, the horizontal cyclone water film dust collector, the electrostatic precipitator, the air duct bridge, and the rigid air duct. Finally, the clean air is sprayed out by the airflow diffuser. The dust is mainly removed by the horizontal cyclone water film dust collector and the electrostatic precipitator.

[0019] The dust removal train uses a mining battery-powered locomotive and is equipped with a tow hook, which meets the requirements for autonomous transportation. The dust removal train moves forward with the tunneling face equipment train and can also be transported by motor, meeting the dust removal requirements of mobile working faces such as shotcrete working faces and hard rock blasting working faces with sporadic dust generation.

[0020] (2) The dust collection hoods for roadway floating dust, transfer machine-belt conveyor dust collection hoods, tunneling machine-transfer machine dust collection hoods, rock loading mechanism dust collection hoods and cutting head dust collection hoods are all retractable dust collection hoods. The dust collection hoods form a negative pressure in a local area, which draws the high concentration of rock dust into the horizontal cyclone water film dust collector. The dust collection hoods operate in an unsealed manner. The dust source is located in the incompletely sealed area outside the dust collection hood opening. This area is the cutting head part. The dust is captured by the suction force of the hood opening. The dust collection hoods are suitable for dust-generating points or equipment that cannot be completely sealed, such as transfer points and tunneling faces.

[0021] The umbrella-shaped folding frame of the dust collection hoods for roadway dust collection, transfer conveyor-belt conveyor dust collection, tunneling machine-transfer conveyor dust collection, rock loading mechanism dust collection, and cutting head dust collection is designed to meet the requirements of short-distance follow-up of dust removal equipment to roadheader operations. The center of the dust collection hood is a hollow suction steel pipe (sucking pipe); a hydraulic cylinder is installed on the suction steel pipe to drive the retraction of the umbrella-shaped folding frame; the hydraulic cylinder drives the umbrella-shaped folding frame to reciprocate, opening and folding the dust collection hood; the umbrella-shaped folding frame is made of high-toughness steel lightweight frame; a flexible air-blowing cloth is fixed to the umbrella-shaped folding frame with wire; the operation of the hydraulic cylinder drives the frame retraction rod to move, thereby opening and closing the umbrella-shaped folding frame, thus enabling the dust collection hood to open under working conditions to achieve the suction effect, and to retract under non-working conditions to allow the cutting head to pass through non-working positions. That is, the dust hood retracts when it is in a narrow position and opens when it is in a working position; it retracts to protect the dust hood when the cutting part passes through a complex position, and opens the dust hood when the cutting part and the dust hood are in the working position.

[0022] Each dust hood has a regulating butterfly valve installed at a certain distance on the suction steel pipe at the rear. The opening and closing degree of the butterfly valve is adjusted according to the amount of dust generated, so that the dust hood operates under optimal conditions, achieving the goals of saving electricity, reducing noise, minimizing airflow disturbance, and improving dust removal efficiency. In addition, foam atomizing nozzles can also be installed on the umbrella-shaped folding frame of the dust hood.

[0023] (3) The two-stage dust removal train runs on the track of the single-head roadway of the tunneling face to meet the requirement of the dust removal train following the working face for a long distance. Atomizing nozzles are installed at the fixed position of the cutting head of the roadheader. The atomizing nozzles use a spray foam generator to replace water spray to increase the surface area of ​​the spray, increase the suspension time of the spray foam, and increase the adsorption effect of the mineral dust, while reducing the explosiveness of the mineral dust. The chemical ratio of the sprayed foam liquid can be adjusted according to the wettability, coagulation and adhesion of the dust being removed. For hydrophilic dust with good wettability (generally ordinary rock dust and low coalification degree rock dust), water-based foaming agents can be used. For hydrophobic dust with poor wettability (generally oil shale rock dust and high coalification degree rock dust), in order to accelerate the wettability of the liquid (foam liquid) on the dust, different proportions of wetting agents can be added according to the different wetting angles to reduce the surface tension between the solid and liquid, increase the foam affinity of the dust, and improve the dust removal effect. It can achieve better dust removal effect with a lower spray volume, reduce water spray volume, reduce mudding degree of tunneling face, and reduce the perceived humidity of tunneling face.

[0024] The spray medium for both internal and external spraying was improved by replacing water with an aqueous solution containing rosin foaming agent and surfactant, which was then sprayed onto the working face through atomizing nozzles. The formulation was adjusted according to the differences in the hydrophilicity and hydrophobicity of the mine dust to be removed, giving the foam higher dust-collecting performance. The combined action of pressurized air from the mine compressed air system and compressed liquid achieved the foaming effect through atomization.

[0025] (4) A horizontal cyclone water film dust collector is installed at the front of the train section, which is suitable for mine car size and roadway size. The dust-laden airflow is introduced tangentially along the front end of the outer cylinder and flows along the spiral airflow channel. When the airflow impacts the water surface in the dust collection water tank at a high speed, some dust particles are absorbed by the water, and water droplets are stirred up at the same time. The airflow carries water droplets and rotates, using the centrifugal force of rotation to provide centrifugal acceleration, accelerating the movement of rock dust and water droplets towards the cylinder wall. Under the action of gravity, the deposits on the cylinder wall are collected in the dust collection water tank. The dust-laden airflow flows continuously through several spiral airflow channels and is purified multiple times, so that more than 70% of the rock dust is captured and separated. This horizontal cyclone water film dust collector has three dust removal functions: cyclone, water film, and water bath. At the same time, this dust collector is a wet dust collector with high dust removal efficiency. It can improve the dust removal effect when the air volume is small, thereby reducing the operating noise of the fan and improving the comfort of personnel at the working face from noise pollution.

[0026] (5) An electrostatic precipitator is installed at the rear of the front section of the train to further purify the airflow using electrostatic dust removal. The airflow purified by the horizontal cyclone water film dust collector still contains uncaptured mineral dust and dust-laden droplets. When this airflow enters the electrostatic precipitator, it can not only remove uncaptured mineral dust, but also act as an electrostatic dehydrator to remove water droplets. Dust particles usually carry a negative charge, which originates from the friction of coal and rock during crushing. The amount of charge depends on temperature and humidity. The charge increases when the temperature rises and decreases when the humidity rises. Electrostatic dust removal can remove fine dust, negatively charged droplets, and foam. The underground production airflow in the mine can optimize the working environment of the working face (including reducing inhalable dust and reducing return air humidity) by passing through the above dust removal train. The dust suppression foam can reduce the explosiveness of the mineral dust at the working face, reduce the rated power of the dust removal fan to reduce the noise at the working face, and the two-section dust removal train can advance along the return air roadway or the tunneling material track with the working face to achieve the effect of stabilizing the dust removal conditions.

[0027] (6) This invention employs a wet dust removal method throughout the entire production line, from foam dust removal at the working face using atomizing nozzles to sequentially passing through cyclone water film dust removal, electrostatic dust removal covering the mineral dust foam, and electrostatic mist removal. The final dust removal product is water-rock dust slurry. The slurry collects at the bottom of the dust collection tank and is discharged from the tank by a slurry discharge screw driven by an explosion-proof motor reducer. The discharged slurry is then collected in watertight ton bags by a collection device and transported by mine cars to the slurry sedimentation tank of the surface wastewater treatment station. This achieves the effect of avoiding secondary dust generation. Simultaneously, water is added to the dust collection tank through the water inlet.

[0028] (7) Intrinsically safe gas system setup: A gas sensor is installed at the air inlet of the horizontal cyclone water film dust collector on the front section of the train. When the gas concentration exceeds the coal mine's first-level gas alarm concentration by 1%, the electrostatic precipitator is de-energized and stops working through gas electrical interlocking to prevent accidental discharge of the electrostatic system and the generation of sparks. When the gas concentration exceeds the coal mine's second-level gas alarm concentration by 1.5%, the entire train's dust removal device stops working through gas electrical interlocking to prevent gas from passing through the fan and to avoid the fan blades colliding with the casing and causing a gas accident. When the gas concentration recovers to the threshold, the train's dust removal device automatically starts. This can prevent gas concentrations exceeding the coal mine's first-level gas alarm concentration by 1% from passing through the dust collection plates of the electrostatic precipitator, thus preventing system errors and the generation of electric sparks that could cause gas accidents. At the same time, this setup can ensure that the axial flow fan always operates in clean air, avoiding the coupling effect between gas and rock dust that could change the lower limit of gas and rock dust explosions, thereby improving the intrinsic safety attributes of the system.

[0029] (8) The rear section of the train is equipped with a counter-rotating axial flow fan, which serves as the main power source for dust collection in the entire train system. The counter-rotating axial flow fan is small in size and its airflow can be adjusted by adjusting the blade angle. The power of the variable frequency motor is adjusted according to the amount of dust generated to achieve energy saving. At the same time, an electrostatic generator is installed on the rear section of the train, arranged side by side with the counter-rotating axial flow fan.

[0030] (9) Wet dust collection is used on the front section of the train to avoid secondary dust generation. The mine dust is collected at the bottom of the dust collection water tank. The screw driven by the explosion-proof motor reducer rotates to discharge the dust-containing slurry. A slurry collection device is arranged at the rear of the front section of the train to meet the requirements of dust removal slurry buffer collection. After the buffer slurry collection container reaches the rated capacity, the concentrated slurry is transported to the material train by the slurry pump and transported to the mine surface slurry sedimentation tank.

[0031] In summary, this invention mounts the dust removal equipment on a train that can move along tracks laid in a single-ended roadway in a coal mine. It can move with the working face, maintaining good dust collection and ensuring gas safety. By combining wet and electrostatic dust removal, the dust removal effect is greatly improved. The horizontal cyclone water film dust collector can achieve good dust removal efficiency with a relatively small suction volume, reaching a dust removal rate of 80%. The electrostatic precipitator can achieve a dust removal rate of 99.9% for mine dust, atomized foam, and water droplets, which are usually negatively charged, while simultaneously collecting foam and water droplets, thus significantly improving the mine's air environment. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the elevation structure of the present invention; Figure 2 for Figure 1 Enlarged views of the equipment on the front and rear sections of the train; Figure 3 for Figure 1 Enlarged view of the central vacuum duct system; Figure 4 for Figure 2 Schematic diagram of the three-dimensional structure of a horizontal cyclone water film dust collector; Figure 5 for Figure 2 Sectional view of AA; Figure 6 for Figure 2 BB section view; Figure 7 for Figure 2 A three-dimensional structural diagram of a medium-sized electrostatic precipitator; Figure 8 for Figure 3 A schematic diagram showing the connection between the central dust hood in its extended state and the hydraulic cylinder; Figure 9 for Figure 3 A schematic diagram showing the connection between the folded dust hood and the hydraulic cylinder. Detailed Implementation

[0034] The technical solutions in the embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0035] like Figures 1-9 As shown, a wet dust removal train device for coal mine tunneling faces includes a front train 2 and a rear train 3 connected in series on the track of a single-ended roadway 1. A belt conveyor 7, a bridge transfer conveyor 8, and a fully mechanized tunneling machine 9 are sequentially arranged at the front end of the front train 2. A horizontal cyclone water film dust collector 4 and an electrostatic precipitator 5 are sequentially installed on the front train 2 from front to back. The air inlet at the front end of the horizontal cyclone water film dust collector 4 is connected to a dust collection pipeline system 6. The dust collection pipeline system 6 is equipped with a roadway floating dust collection hood 11, a transfer conveyor-belt conveyor dust collection hood 12, a tunneling machine-transfer conveyor dust collection hood 13, a rock loading mechanism dust collection hood 14, and a cutting head dust collection hood 15. The roadway floating dust collection hood 11 is located on... Behind the belt conveyor 7, the dust hood 12 of the transfer machine-belt conveyor is located at the junction of the rear end of the bridge transfer machine 8 and the front end of the belt conveyor 7. The dust hood 13 of the tunneling machine-transfer machine is located at the junction of the front end of the bridge transfer machine 8 and the rear end of the transfer machine. The dust hood 14 of the rock loading mechanism is located at the rear end of the rock loading mechanism of the integrated mechanized tunneling machine 9. The dust hood 15 of the cutting head is located above and behind the cutting head of the integrated tunneling machine. On the rear section of the train 3, an electrostatic generator 16 and a counter-rotating axial flow fan 17 are respectively arranged side by side on the left and right. The front end of the electrostatic generator 16 is connected to the electrostatic precipitator 5 through the cable tray 18. The air outlet at the rear end of the electrostatic precipitator 5 is connected to the air inlet at the front end of the counter-rotating axial flow fan 17 through the air duct tray 19.

[0036] The dust collection hood 11 for roadway floating dust, the dust collection hood 12 for transfer machine-belt conveyor, the dust collection hood 13 for tunneling machine-transfer machine, the dust collection hood 14 for rock loading mechanism, and the dust collection hood 15 for cutting head all include an umbrella-shaped folding frame 20 coaxially mounted on the dust collection pipe. The telescopic folding of the umbrella-shaped folding frame 20 is driven by a hollow hydraulic cylinder 22 coaxially mounted on the dust collection pipe 21.

[0037] The horizontal cyclone water film dust collector 4 includes a horizontally arranged outer cylinder 23 and a dust collection water tank 28. The front and rear ends of the outer cylinder 23 are equipped with blocking plates 24. An inner cylinder 25 is arranged coaxially inside the outer cylinder 23. A cylindrical cavity is formed between the outer circle of the inner cylinder 25 and the inner circle of the outer cylinder 23. A spiral guide plate 26 is provided between the inner cylinder 25 and the outer cylinder 23 to form a spiral airflow channel in the cylindrical cavity. The air inlet at the front end of the spiral airflow channel is connected to the air outlet of the dust collection pipeline system 6. A gas sensor 27 is set at the front end of the spiral airflow channel of the outer cylinder 23. The dust collection water tank 28 is located below the outer cylinder 23 and extends backward to below the electrostatic precipitator 5. A rectangular hole communicating with the dust collection water tank 28 is opened along the length direction at the bottom of the outer cylinder 23. The water level in the dust collection water tank 28 is inside the outer cylinder 23 and has an air passage gap with the lowest point of the inner cylinder 25.

[0038] The electrostatic precipitator 5 includes a dust collection box 29. The dust collection box 29 has multiple sets of identical structures arranged from front to back. Each set of electrostatic precipitators 5 includes multiple dust collection plates 30 arranged vertically in the front-back direction. A corona electrode wire 31 is provided between any two adjacent dust collection plates 30. The upper ends of all corona electrode wires 31 are connected to a high-voltage bus terminal 32. The high-voltage bus terminal 32 is connected to the electrostatic generator 16. A grounding wire 33 is connected to the lower side of the dust collection box 29. The bottom of the dust collection box 29 is open and fixedly connected to the top of the dust collection water tank 28. A water inlet 34 for adding water to the dust collection water tank 28 is provided in the middle of the rear end of the dust collection box 29. A water inlet sealing plug is provided at the water inlet 34.

[0039] The dust collection water tank 28 has a mud discharge screw 35 at the bottom along the front-to-back direction. The front and rear ends of the mud discharge screw 35 are rotatably connected to the front and rear side plates of the dust collection water tank 28, respectively. An explosion-proof motor reducer 36 is provided on the outer side of the front end of the dust collection water tank 28. The output shaft of the explosion-proof motor reducer 36 is connected to the front end of the mud discharge screw 35. A mud discharge pipe 37 is provided on the rear side plate of the dust collection water tank 28 below the mud discharge screw 35. A mud discharge valve is provided on the mud discharge pipe 37.

[0040] The electrostatic generator 16 includes a power frequency power inlet 38, a power conditioner 39, a power frequency step-up transformer 40, a high-voltage rectifier 41, and a high-voltage outlet terminal 42. The electrostatic generator 16 is connected to an inlet cable tray 49 at its rear end.

[0041] The counter-rotating axial flow fan 17 includes a drive motor 44 and a rigid air duct 43 arranged horizontally in the front-to-back direction. The rigid air duct 43 is provided with a first set of counter-rotating blades 45 and a second set of counter-rotating blades 46, both of which are connected to the drive motor 44. The front end of the rigid air duct 43 is connected to the rear end of the air duct bridge 19. The rear end of the rigid air duct 43 is provided with a conical airflow diffuser 47 that is thicker at the rear and thinner at the front.

[0042] The working principle of this invention and its beneficial effects are as follows: (1) Under the action of the counter-rotating axial flow fan 17, the air carrying rock dust is collected by the roadway dust collection hood 11, the transfer machine-belt conveyor dust collection hood 12, the tunneling machine-transfer machine dust collection hood 13, the rock loading mechanism dust collection hood 14, and the cutting head dust collection hood 15. The air then passes through the dust collection pipeline system 6, the horizontal cyclone water film dust collector 4, the electrostatic precipitator 5, the air duct bridge 19, and the rigid air duct 43. Finally, the clean air is sprayed out by the airflow diffuser 47. The dust is mainly removed by the horizontal cyclone water film dust collector 4 and the electrostatic precipitator 5.

[0043] The dust removal train uses a mining battery-powered locomotive and is equipped with a tow hook, which can meet the requirements for autonomous transportation of the dust removal train. The dust removal train moves forward with the equipment train at the tunneling face and can also be transported by motor, meeting the dust removal requirements of mobile working faces such as shotcrete working faces, hard rock blasting working faces, and other sporadic dust-generating working faces.

[0044] (2) The dust collection hoods 11 for roadway floating dust, 12 for transfer machine-belt conveyor, 13 for tunneling machine-transfer machine, 14 for rock loading mechanism, and 15 for cutting head all adopt retractable dust collection hoods to form negative pressure in a local area, sucking the high concentration of rock dust into the horizontal cyclone water film dust collector 4; the dust collection hoods operate in an unsealed manner, and the dust source is located in the incompletely sealed area outside the dust collection hood opening. This area is the cutting head part, and the dust is captured by the suction force of the hood opening. The dust collection hoods are suitable for dust-generating points or equipment that cannot be completely sealed, such as transfer points, tunneling working faces 10, etc.

[0045] The umbrella-shaped folding frame 20 of the dust collection hood 11 for roadway floating dust, the dust collection hood 12 for transfer conveyor-belt conveyor, the dust collection hood 13 for tunneling machine-transfer conveyor, the dust collection hood 14 for rock loading mechanism, and the dust collection hood 15 for cutting head meets the requirement of dust removal equipment following the operation of the roadheader over short distances. The center of the dust collection hood is a hollow dust collection steel pipe (dust collection pipe 21); a hydraulic cylinder 22 is installed on the dust collection steel pipe to drive the retraction of the umbrella-shaped folding frame 20; the hydraulic cylinder 22 drives the umbrella-shaped folding frame 20 to reciprocate to open and fold the dust collection hood; the umbrella-shaped folding frame 20 is made of high-toughness steel lightweight frame; a flexible air cloth is fixed to the umbrella-shaped folding frame 20 with iron wire; the operation of the hydraulic cylinder 22 drives the frame retraction rod to move, thereby driving the opening and retraction of the umbrella-shaped folding frame 20, so that the dust collection hood opens under working conditions to meet the suction effect, and retracts under non-working conditions to allow the cutting head to pass through non-working positions. That is, the dust hood retracts when it is in a narrow position and opens when it is in a working position; it retracts to protect the dust hood when the cutting part passes through a complex position, and opens the dust hood when the cutting part and the dust hood are in the working position.

[0046] Each dust hood has a suction pipe with adjustable airflow butterfly valves 48 installed at a certain distance at the rear. The opening and closing degree of the butterfly valves 48 is adjusted according to the amount of dust generated, so that the dust hood operates under optimal conditions, achieving the goals of saving electricity, reducing noise, minimizing airflow disturbance, and improving dust removal efficiency. In addition, foam atomizing nozzles can also be installed on the umbrella-shaped folding frame 20 of the dust hood.

[0047] (3) The two-stage dust removal train runs on the track of the single-ended roadway 1 of the tunneling face 10 to meet the requirement of the dust removal train following the working face for a long distance. Atomizing nozzles are installed at the fixed position of the cutting head of the roadheader. The atomizing nozzles use a spray foam generator to replace water spray to increase the surface area of ​​the spray, increase the suspension time of the spray foam, and increase the adsorption effect of the mineral dust, while reducing the explosiveness of the mineral dust. The chemical ratio of the sprayed foam liquid can be adjusted according to the wettability, coagulation and adhesion of the dust being removed. For hydrophilic dust with good wettability (generally ordinary rock dust and low coalification degree rock dust), water-based foaming agents can be used. For hydrophobic dust with poor wettability (generally oil shale rock dust and high coalification degree rock dust), in order to accelerate the wettability of the liquid (foam liquid) on the dust, different proportions of wetting agents can be added according to the different wetting angles to reduce the surface tension between the solid and liquid, increase the foam affinity of the dust, and improve the dust removal effect. It can achieve better dust removal effect with a lower spray volume, reduce water spray volume, reduce mudding degree of tunneling face, and reduce the perceived humidity of tunneling face.

[0048] The spray medium for both internal and external spraying was improved by replacing water with an aqueous solution containing rosin foaming agent and surfactant, which was then sprayed onto the working face through atomizing nozzles. The formulation was adjusted according to the differences in the hydrophilicity and hydrophobicity of the mine dust to be removed, giving the foam higher dust-collecting performance. The combined action of pressurized air from the mine compressed air system and compressed liquid achieved the foaming effect through atomization.

[0049] (4) A horizontal cyclone water film dust collector 4 is installed on the front side of the front section of the train 2. It is suitable for mine car size and roadway size. The dust-laden airflow is introduced tangentially along the front end of the outer cylinder 23 and flows along the spiral airflow channel. When the airflow impacts the water surface in the dust collection water tank 28 at a high speed, some dust particles are absorbed by the water and water droplets are stirred up. The airflow carries water droplets and rotates. The centrifugal force of rotation provides centrifugal acceleration, which accelerates the movement of rock dust and water droplets towards the cylinder wall. Under the action of gravity, the deposits on the cylinder wall are collected in the dust collection water tank 28. The dust-laden airflow flows continuously through several spiral airflow channels and is purified multiple times, so that more than 70% of the rock dust is captured and separated. The horizontal cyclone water film dust collector 4 has three dust removal functions: cyclone, water film, and water bath. At the same time, the dust collector is a wet dust collector with high dust removal efficiency. It can improve the dust removal effect when the air volume is small, thereby reducing the noise of the fan and improving the comfort of the personnel at the working face from noise pollution.

[0050] (5) An electrostatic precipitator 5 is installed on the rear side of the front section of train 2 to further purify the airflow using electrostatic dust removal. The airflow purified by the horizontal cyclone water film dust collector 4 still contains uncaptured mineral dust and dust-laden droplets. This airflow enters the electrostatic precipitator 5, which not only removes the uncaptured mineral dust but also acts as an electrostatic dehydrator to remove water droplets. Dust particles are usually negatively charged, and their charge originates from the friction of coal and rock during crushing. The amount of charge depends on temperature and humidity; the charge increases with increasing temperature and decreases with increasing humidity. Electrostatic dust removal can remove fine dust, negatively charged droplets, and foam. The underground production airflow in the mine can be optimized by the above-mentioned dust removal trains (including reducing inhalable dust and reducing return air humidity). The dust suppression foam can reduce the explosiveness of the mine dust at the working face, reduce the rated power of the dust removal fan to reduce the noise at the working face, and the two-section dust removal trains can advance along the return air roadway or the track of the tunneling material train line with the working face to achieve the effect of stabilizing the dust removal conditions.

[0051] (6) This invention employs a wet dust removal method throughout the entire production line, from foam dust removal at the working face using atomizing nozzles to sequentially removing dust through cyclone water film, electrostatic removal of the covered mineral dust foam, and electrostatic removal of mist droplets. The final dust removal product is water-rock dust slurry. The slurry collects at the bottom of the dust collection tank 28 and is discharged from the dust collection tank 28 by a slurry discharge screw 35 driven by an explosion-proof motor reducer 36. The discharged slurry is then collected into watertight ton bags by a collection device and transported by mine cars to the slurry sedimentation tank of the surface sewage treatment station. This achieves the effect of avoiding secondary dust generation. At the same time, water is added to the dust collection tank 28 through the water inlet 34.

[0052] (7) Intrinsic safety system setup for gas: A gas sensor 27 is installed at the air inlet of the horizontal cyclone water film dust collector 4 on the front section of train 2. When the gas concentration is 1% higher than the level 1 alarm concentration of coal mine gas, the electrostatic precipitator 5 is de-energized and stops working through gas electrical interlocking to avoid sparks caused by accidental discharge of the electrostatic system; when the gas concentration is 1.5% higher than the level 2 alarm concentration of coal mine gas, the entire train dust removal device stops working through gas electrical interlocking to prevent gas from passing through the fan and avoid gas accidents caused by fan blades colliding with the casing. When the gas concentration recovers to the threshold, the train dust removal device automatically starts. This can prevent gas concentrations exceeding the level 1 alarm concentration of coal mine gas from passing through the dust collection plate 30 of the electrostatic precipitator 5, thus avoiding gas accidents caused by electric sparks due to system errors. At the same time, this setup can ensure that the axial flow fan always operates in clean air, avoiding changes in the lower explosion limit of gas and rock dust caused by the coupling effect of gas and rock dust, and improving the intrinsic safety attributes of the system.

[0053] (8) The rear section of train 3 is equipped with a counter-rotating axial flow fan 17, which serves as the main power source for dust collection in the entire train system. The counter-rotating axial flow fan 17 is small in size and its power can be adjusted by adjusting the blade angle. The power of the variable frequency motor is adjusted according to the amount of dust generated to achieve energy saving. At the same time, an electrostatic generator 16 is arranged on the rear section of train 3, arranged side by side with the counter-rotating axial flow fan 17.

[0054] (9) The front section of train 2 adopts wet dust collection operation to avoid secondary dust generation. The mine dust is collected at the bottom of the dust collection water tank 28. The screw driven by the explosion-proof motor reducer 36 rotates to achieve the purpose of discharging the dust-containing mud. The mud collection device arranged at the rear of the front section of train 2 can meet the requirements of dust removal mud buffer collection. After the buffer mud collection container reaches the rated capacity, the concentrated mud is transported to the material train by the mud pump and transported to the surface mud sedimentation tank of the mine.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A wet dust removal train device for coal mine tunneling faces, comprising a front train and a rear train connected in series on a track in a dead-end roadway, wherein a belt conveyor, a bridge transfer conveyor, and a fully mechanized tunneling machine are sequentially arranged at the front end of the front train, characterized in that: The front section of the train is equipped with a horizontal cyclone water film dust collector and an electrostatic dust collector, arranged sequentially from front to back. The air inlet at the front of the horizontal cyclone water film dust collector is connected to a dust collection pipeline system. This system includes dust collection hoods for roadway floating dust, transfer conveyor-belt conveyor, tunneling machine-transfer conveyor, rock loading mechanism, and cutting head. The roadway floating dust collection hood is located behind the belt conveyor, while the transfer conveyor-belt conveyor dust collection hood is located at the junction of the rear end of the bridge transfer conveyor and the front end of the belt conveyor. The tunneling... The dust hood for the transfer machine is located at the junction of the front and rear ends of the bridge transfer machine. The dust hood for the rock loading mechanism is located at the rear end of the rock loading mechanism of the mechanized tunneling machine. The dust hood for the cutting head is located above and behind the cutting head of the mechanized tunneling machine. On the rear section of the train, there are electrostatic generators and counter-rotating axial flow fans arranged side by side. The front end of the electrostatic generator is connected to the electrostatic precipitator through a cable tray. The air outlet at the rear end of the electrostatic precipitator is connected to the air inlet at the front end of the counter-rotating axial flow fan through a duct cable tray.

2. The wet dust removal train device for coal mine tunneling face construction according to claim 1, characterized in that: Dust collection hoods for roadways, transfer conveyors / belt conveyors, tunneling machines / transfer conveyors, rock loading mechanisms, and cutting heads all include an umbrella-shaped folding frame coaxially mounted on the suction pipe. The extension and folding of the umbrella-shaped folding frame are driven by a hollow hydraulic cylinder coaxially mounted on the suction pipe.

3. The wet dust removal train device for coal mine tunneling face construction according to claim 2, characterized in that: The horizontal cyclone water film dust collector includes a horizontally arranged outer cylinder and a dust collection water tank. The front and rear ends of the outer cylinder are equipped with blocking plates. An inner cylinder is arranged coaxially inside the outer cylinder, and a cylindrical cavity is formed between the outer circle of the inner cylinder and the inner circle of the outer cylinder. A spiral guide plate is provided between the inner cylinder and the outer cylinder to form a spiral airflow channel in the cylindrical cavity. The air inlet at the front end of the spiral airflow channel is connected to the air outlet of the dust collection pipeline system. A gas sensor is installed at the front end of the spiral airflow channel of the outer cylinder. The dust collection water tank is located below the outer cylinder and extends backward to below the electrostatic precipitator. A rectangular hole communicating with the dust collection water tank is opened along the length direction at the bottom of the outer cylinder. The water level in the dust collection water tank is inside the outer cylinder and has an air passage gap with the lowest point of the inner cylinder.

4. The wet dust removal train device for coal mine tunneling face construction according to claim 3, characterized in that: The electrostatic precipitator includes a dust collection box, which contains multiple identical sets of equipment arranged from front to back. Each set of electrostatic precipitators includes multiple dust collection plates arranged vertically along the front-to-back direction. A corona electrode is provided between any two adjacent dust collection plates. The upper ends of all the corona electrode lines are connected to a high-voltage bus terminal, which is connected to an electrostatic generator. A grounding wire is connected to the lower side of the dust collection box. The bottom of the dust collection box is open and fixedly connected to the top of the dust collection water tank. A water inlet for adding water to the dust collection water tank is provided in the middle of the rear end of the dust collection box, and a water inlet sealing plug is provided at the water inlet.

5. The wet dust removal train device for coal mine tunneling face construction according to claim 4, characterized in that: The lower part of the dust collection water tank is equipped with a mud discharge screw along the front-to-back direction. The front and rear ends of the mud discharge screw are rotatably connected to the front and rear side plates of the dust collection water tank, respectively. An explosion-proof motor reducer is provided on the outer side of the front end of the dust collection water tank. The output shaft of the explosion-proof motor reducer is connected to the front end of the mud discharge screw. A mud discharge pipe is provided on the rear side plate of the dust collection water tank below the mud discharge screw, and a mud discharge valve is provided on the mud discharge pipe.

6. The wet dust removal train device for coal mine tunneling face construction according to claim 1, characterized in that: The electrostatic generator includes an industrial frequency power input line, a regulator, an industrial frequency step-up transformer, a high-voltage rectifier, and high-voltage output terminals; the electrostatic generator is connected to an input cable tray at the rear end.

7. The wet dust removal train device for coal mine tunneling face construction according to claim 1, characterized in that: The counter-rotating axial flow fan includes a drive motor and a rigid duct arranged horizontally in the front-to-back direction. The rigid duct is equipped with a first set of counter-rotating blades and a second set of counter-rotating blades, both of which are connected to the drive motor. The front end of the rigid duct is connected to the rear end of the duct bridge. The rear end of the rigid duct is equipped with a conical airflow diffuser that is wider at the rear and narrower at the front.

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