A coal conveying dust control system

Abstract

The utility model belongs to but is not limited to dust removal equipment technical field, especially related to a coal conveying dust control system, telescopic material guide cover is set in coal transfer node for guiding coal blanking. The telescopic material guide cover is connected with the negative pressure dust cover through the flexible sealing element, and the two form a closed negative pressure cavity. Dust recovery and material return device The outlet of the negative pressure dust cover is connected with the dust collection tank, and the bottom of the dust collection tank is provided with a scraper material return device or a spiral material return device. The front end separation equipment is arranged between the negative pressure dust cover and the dust collection tank. The pipeline spraying system is arranged on the pipeline between the negative pressure dust cover and the vacuum cleaning unit, and one pipeline spray head is arranged every 2m on the pipeline. The vacuum cleaning unit is connected with the fan, and comprises a primary filter, a secondary filter cartridge filter and a fan.

Description

Technical Field

[0001] This utility model belongs to, but is not limited to, the field of dust removal equipment technology, and particularly relates to a coal conveying dust control system. Background Technology

[0002] During coal transportation, the unloading and stockpiling processes at transfer nodes generate a large amount of dust, which not only causes serious air pollution and harms the health of workers, but also leads to increased equipment wear and frequent pipeline blockages due to dust accumulation, significantly increasing operation and maintenance costs. Existing dust control systems for coal conveying have several shortcomings: First, dust collection efficiency is low. Traditional dust hoods and material guiding devices have poor sealing performance, making dust leakage easy. In complex environments such as open-air and underground, the collection effect is even less ideal due to wind and space limitations. Second, equipment wear is severe. Large particles and gangue in the coal directly impact the material guiding hood, pipes, and filter components, resulting in short equipment lifespan and frequent replacements that significantly increase costs. Third, dust recovery is inconvenient. Most systems can only collect dust but cannot easily return it to the conveyor belt or designated recycling points, leading to resource waste. Fourth, pipes are prone to blockage and difficult to clean. Dust (especially moisture-containing dust) easily adheres to pipes, and there is a lack of effective self-cleaning methods. Frequent manual cleaning is required during operation and maintenance, which is time-consuming and labor-intensive. In addition, the adaptability to various scenarios is poor. Existing systems lack targeted designs for different scenarios such as underground explosion protection, humid salt spray in ports, and long-distance open-air transportation, making it difficult to simultaneously meet the multiple requirements of efficient dust removal, long-term equipment lifespan, and scenario adaptability. These problems severely restrict the environmental friendliness and economy of coal transportation, and there is an urgent need for a coal transportation dust control system that can efficiently capture dust, extend equipment life, facilitate dust recovery, and adapt to multiple scenarios.

[0003] Closest prior art: CN106081562A ("Method and apparatus for dust control in coal conveying systems of power plants")

[0004] Existing technical problems: Although the technology proposes to control dust concentration by "enclosing the material guide chute structure, reducing the positive pressure of the airflow in the material guide chute, and spraying the non-sealed areas at both ends of the belt", its coverage is relatively narrow: it mainly targets the spraying and sealing treatment at the unloading / transfer end, and has not yet formed a full-process dust control network along the conveying path with multiple nodes, telescopic material guide hoods + negative pressure sealed chambers + graded separation + recycling and reuse; therefore, in the actual coal conveying process, problems such as dust overflow at transfer nodes, inconsistent pipeline spraying intervals, and unsystematic recycling structures may still occur. Utility Model Content

[0005] In view of the problems existing in the prior art, this utility model provides a coal conveying dust control system.

[0006] This utility model is implemented as follows: a coal conveying dust control system includes a conveyor belt, a retractable guide hood, a negative pressure dust collection hood, a vacuum dust collection unit, a dust recovery device, and also includes a front-end separation device and a pipeline spraying system.

[0007] The retractable guide cover is installed at the coal transfer node to guide the coal falling.

[0008] The retractable material guide cover is connected to the negative pressure dust collection cover through a flexible seal, and the two together form a closed negative pressure chamber.

[0009] The outlet of the negative pressure dust collection hood of the dust recovery and return device is connected to the dust collection trough, and the bottom of the dust collection trough is equipped with a scraper return device or a spiral return device.

[0010] The multi-module distributed dust collection structure system includes multiple dust collection modules, which are distributed at different transfer nodes along the coal conveying path to form a dust control network throughout the entire process, ensuring that there is no large-scale dust spillage during the entire coal conveying process.

[0011] The front-end separation device is located between the negative pressure dust collection hood and the dust collection tank, and is used to separate particles with a diameter greater than 5-50mm.

[0012] The pipeline spraying system is installed on the pipeline between the negative pressure dust collection hood and the vacuum dust collection unit, with a pipeline nozzle installed every 2m.

[0013] The vacuum cleaning unit is connected to the fan and includes a primary filter, a secondary cartridge filter, and the fan.

[0014] Furthermore, the dust recovery device specifically includes:

[0015] Mud-water mixture separator: After the mud-water mixture enters the separator, the water and mud-water mixture are separated from the gas by airflow combined with spray and water seal devices. The solid material settles to the bottom and is discharged for collection. The gas containing some water vapor enters the subsequent process after demisting.

[0016] Terminal filtration equipment: performs fine filtration of gas to ensure that the discharged gas meets environmental protection requirements. If it is necessary to recover powdered materials, the materials can be transported to the designated location through the internal powder pneumatic conveying device.

[0017] Furthermore, the inner wall of the retractable material guide cover is provided with a wear-resistant lining, which is made of wear-resistant rubber or polymer wear-resistant sheet material and can withstand the impact and friction of coal falling.

[0018] Furthermore, the guide hood adopts a corrugated tube or sleeve telescopic structure, which can be flexibly adjusted according to the material drop height to adapt to different working conditions.

[0019] Furthermore, the negative pressure chamber can completely enclose the dust generated during material feeding, preventing dust from overflowing.

[0020] Furthermore, scrapers or spiral structures can directly return the collected dust to the conveyor belt, achieving dust recycling.

[0021] Furthermore, the front-end separation equipment is mounted on the conveyor belt, and the separated large particles are directly discharged to the conveyor belt, avoiding large particles from entering subsequent pipelines and causing blockages or excessive wear on the equipment.

[0022] Furthermore, when collecting mud-water mixtures or water-containing dust, the nozzles spray water to prevent dust from adhering to the inner wall of the pipe; the pipe inclination angle of the pipe spraying system is not less than 0.2% - 0.5%, and it is inclined towards the front-end separation equipment.

[0023] Furthermore, after the airflow undergoes coarse filtration by the primary filter and fine filtration by the secondary cartridge filter, the clean air is discharged into the atmosphere from the fan outlet. If pneumatic conveying of dust is required, the air discharged from the fan is used as the air source through PLC control to pneumatically convey the collected powdery material to the silo.

[0024] Based on the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by this utility model are as follows:

[0025] This invention can solve the problems existing in the prior art:

[0026] (1) Problem of low dust collection efficiency: By forming a closed negative pressure chamber through the flexible sealing part between the telescopic guide hood and the negative pressure dust collection hood, combined with the multi-module distributed dust collection structure, the dust can be fully enclosed and collected throughout the entire process, greatly reducing dust overflow, and ensuring efficient collection even in complex environments such as open-air and underground.

[0027] (2) Problem of severe equipment wear: The inner wall of the telescopic guide cover is equipped with a wear-resistant lining to resist the impact and friction of coal particles and gangue; the front-end separation equipment separates large particles with a diameter greater than 5-50mm, preventing them from entering the subsequent pipeline and filter components, and significantly extending the service life of the guide cover, pipeline and filter equipment.

[0028] (3) Problem of inconvenient dust recycling: The scraper or spiral return device at the bottom of the dust collection tank can directly send the dust back to the conveyor belt; the pneumatic conveying function of the vacuum dust collection unit can automatically transport the powdered material to the designated recycling point, realize efficient dust recycling and utilization, and avoid resource waste.

[0029] (4) Problems of easy blockage and difficult cleaning of pipes: The pipe spraying system is equipped with a nozzle every 2m to spray water when collecting water-containing dust to prevent dust from sticking to the pipe; the pipe is designed with an inclination angle of not less than 0.2% - 0.5% to facilitate the discharge of spray mixture, realize the self-cleaning of pipes, and reduce the maintenance cost of manual cleaning.

[0030] (5) Problem of poor adaptability to multiple scenarios: For different scenarios such as long-distance open-air transportation, explosion-proof underground transportation, and humid port transportation, the system can be made to operate stably and efficiently in various scenarios by adjusting the structure of the guide hood, equipment materials (such as explosion-proof fans and seawater corrosion-resistant rubber), and system parameters (such as fan air volume and pipeline inclination) to meet the special needs of different environments.

[0031] The beneficial effects of this utility model include:

[0032] Highly efficient dust capture: The negative pressure chamber formed by the flexible sealing element is combined with the multi-module distributed structure to achieve fully enclosed, full-process dust capture, greatly reducing dust spillage.

[0033] Extended equipment lifespan: The wear-resistant lining of the telescopic feed hood and the large particle separation function of the front-end separation equipment effectively reduce equipment wear and extend the service life of the feed hood, pipes and filter components.

[0034] Convenient dust recycling: The dust collection trough's return device and pneumatic conveying function enable automated dust recycling and utilization, reducing resource waste.

[0035] Pipeline self-cleaning: The spraying and inclined design of the pipeline spraying system prevents dust from adhering to the pipeline, ensuring long-term unobstructed flow and reducing operation and maintenance costs. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the coal conveying dust control system provided in this embodiment of the utility model;

[0037] Figure 2 This is a schematic diagram of the vacuum dust collection unit provided in this embodiment of the utility model;

[0038] Figure 3 This is a schematic diagram of the dust recovery device provided in an embodiment of the present invention;

[0039] Figure 4 This is a schematic diagram of the pipeline spraying system provided in an embodiment of the present utility model;

[0040] In the diagram: 1. Conveyor belt; 2. Telescopic guide hood; 3. Negative pressure dust collection hood; 4. Vacuum dust collection unit; 5. Dust recovery device. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this utility model.

[0042] like Figure 1 As shown, the coal conveying dust control system provided in this embodiment includes a conveyor belt 1, a retractable guide hood 2, a negative pressure dust suction hood 3, a vacuum dust suction unit, a dust recovery device, and also includes front-end separation equipment, a pipeline spraying system, and other components. The specific structure is as follows:

[0043] The retractable guide hood 2 is installed at the coal transfer node to guide the coal drop. Its inner wall is lined with a wear-resistant layer made of wear-resistant rubber or high-polymer wear-resistant sheet material, which can withstand the impact and friction of the falling coal, significantly extending the service life of the guide hood. The guide hood adopts a corrugated or sleeve-type retractable structure, which can be flexibly adjusted according to the drop height to adapt to different working conditions.

[0044] The negative pressure dust collection hood 3 is connected to the flexible sealing structure of the retractable material guide hood 2 via a flexible sealing component (such as a rubber flexible connector or a canvas flexible connector). Together, they form a closed negative pressure chamber. The negative pressure chamber allows the dust generated by the falling material to be completely contained within the chamber, preventing dust from overflowing and significantly improving dust collection efficiency.

[0045] The coal conveying dust control system provided in this embodiment includes a conveyor belt 1, a retractable guide hood 2, a negative pressure dust suction hood 3, a vacuum dust suction unit 4, a dust recovery device 5, and front-end separation equipment and a pipeline spraying system, etc., with a compact overall structure and reasonable layout. The conveyor belt 1 is the basic conveying mechanism of the system, used to transport coal from upstream to downstream processes. The guide hood 2 and the dust suction hood 3 are sequentially installed above it to achieve a synergistic effect of guiding flow and controlling dust during the material falling process. The conveyor belt support adopts a steel structure to ensure stability under high loads and facilitate assembly and positioning with the upper cover.

[0046] The retractable guide hood 2 is installed at the coal transfer node. Its main function is to guide the coal flow towards the center of the conveyor belt, preventing coal flow deviation and dust scattering. The guide hood 2 adopts a corrugated pipe or sleeve-type telescopic structure, composed of multiple sleeves or flexible corrugated covers. Its length can be adjusted by sliding rails or telescopic rods to adapt to different heights of the drop opening. Its inner wall is equipped with a wear-resistant lining, which can be made of high-molecular polyurethane board or wear-resistant rubber board, to absorb the impact of coal blocks and reduce wear. The bottom end of the guide hood is sealed to the negative pressure dust suction hood 3 through a flexible sealing canvas or rubber soft connection, forming a complete closed drop space.

[0047] The negative pressure dust collection hood 3 is installed above the material guide hood. Its semi-enclosed dome structure is used to establish a stable negative pressure dust collection chamber. This hood is connected to the vacuum collection unit 4 via a suction pipe. The vacuum collection unit 4 is equipped with a high-efficiency centrifugal fan and a multi-stage filtration system. After the fan starts, a continuous negative pressure airflow is formed inside the hood, which promptly draws away the dust and gas escaping from the material guide hood 2 through the pipe, thereby achieving comprehensive dust control in the material drop area. The negative pressure dust collection hood 3 has a baffle plate in its structure, which ensures uniform airflow distribution and prevents dust leakage due to insufficient local suction.

[0048] The vacuum dust collection unit 4 is the power and central component of the system, mainly consisting of a negative pressure fan, a silencer box, a filter chamber, and an exhaust pipe. This device maintains a slight negative pressure in the entire material guide hood and dust collection hood area by controlling the airflow and pipe velocity. This ensures efficient dust absorption while preventing excessive negative pressure from affecting the stability of the coal flow. The dust-laden gas extracted by the dust collection unit 4 further enters the dust recovery device 5. The dust recovery device 5 includes a cyclone separator, a bag filter, and an ash storage tank. The cyclone separator uses centrifugal force to initially separate large dust particles, while the bag filter further captures fine dust. The purified gas is discharged through the exhaust port.

[0049] The entire system is assembled and connected via flanges, supports, and flexible pipes, providing excellent sealing and ease of assembly and disassembly. During operation, coal travels along conveyor belt 1 and falls through guide hood 2. Dust is immediately captured by negative pressure dust collection hood 3, then sucked in by vacuum dust collection unit 4 and purified in stages within dust recovery device 5. Through this coordinated approach, the system achieves closed-loop collection and cyclic purification of dust throughout the entire coal conveying process, significantly reducing dust emissions, improving the working environment, and realizing efficient, safe, and environmentally friendly coal conveying control.

[0050] like Figure 2 As shown, the outlet of the negative pressure dust collection hood 3 in the dust recovery and return device is connected to the dust collection trough, and the bottom of the dust collection trough is equipped with a scraper return device or a spiral return device. The collected dust can be directly sent back to the conveyor belt 1 through the scraper or spiral structure, realizing the recycling of dust and reducing resource waste.

[0051] like Figure 3 As shown, the multi-module distributed dust collection structure system includes multiple dust collection modules, which are distributed at different transfer nodes along the coal conveying path to form a dust control network throughout the entire process, ensuring that there is no large-scale dust overflow during the entire coal conveying process.

[0052] The front-end separation device is located between the negative pressure dust collection hood 3 and the dust collection tank, and is used to separate particles with a diameter greater than 5-50mm. This device is mounted on the conveyor belt 1, and the separated large particles can be directly discharged to the conveyor belt 1, avoiding large particles from entering subsequent pipelines and causing blockages or excessive wear on the equipment.

[0053] like Figure 4 As shown, the pipeline spraying system is installed on the pipeline between the negative pressure dust collection hood 3 and the vacuum dust collection unit, with a pipeline nozzle installed every 2 meters. When collecting mud-water mixtures or water-containing dust, the nozzles spray water to prevent dust from adhering to the inner wall of the pipeline; the pipeline inclination angle of the pipeline spraying system is not less than 0.2% - 0.5%, and it is inclined towards the front-end separation equipment to facilitate the discharge of sprayed wastewater and dust mixtures and avoid sludge accumulation in the pipeline.

[0054] The vacuum dust collection unit is connected to the fan and includes a primary filter, a secondary cartridge filter, and the fan. After the airflow undergoes coarse filtration by the primary filter and fine filtration by the secondary cartridge filter, the clean air is discharged into the atmosphere from the fan outlet. If pneumatic conveying of dust is required, it can be controlled by a PLC to use the air discharged from the fan as an air source to pneumatically convey the collected powdery material to a designated location (such as a silo).

[0055] Dust recovery unit (sludge-water separation and terminal filtration)

[0056] Mud-water mixture separator: When processing water-containing dust, the mud-water mixture enters the separator and uses airflow combined with spray and water seal devices to separate the water and mud-water mixture from the gas. The solid material settles to the bottom and is discharged for collection, while the gas containing some water vapor enters the subsequent process after demisting.

[0057] Terminal filtration equipment: performs fine filtration of gas to ensure that the discharged gas meets environmental protection requirements. At the same time, if it is necessary to recover powdered materials, the materials can be transported to the designated location through the internal powder pneumatic conveying device.

[0058] Coal is transported to the transfer node by conveyor belt 1 and guided to fall by retractable guide hood 2. The guide hood forms a closed negative pressure chamber with the negative pressure dust collection hood 3 through a rubber flexible connection. After the fan is started, negative pressure is generated in the negative pressure chamber, and the dust generated by the falling material is sucked into the negative pressure dust collection hood 3.

[0059] Dust first enters the front-end separation equipment, where particles with a diameter greater than 5-50mm are separated and directly discharged back to conveyor belt 1; the remaining dust enters the dust collection trough with the airflow, and the spiral return device at the bottom of the dust collection trough sends the dust back to conveyor belt 1.

[0060] The airflow continues into the pipeline spray system (if it contains water, the spray will be activated), and is then transported through the pipeline to the vacuum dust collection unit. It is filtered sequentially through a primary filter and a secondary cartridge filter, and the clean air is discharged by the fan. If pneumatic conveying is required, the PLC controls the activation of the pneumatic conveying module to deliver the powdered material to the designated location.

[0061] If dealing with water-containing dust, the airflow enters the mud-water mixture separator, the separated solid material is discharged, the gas is demisted and enters the terminal filtration equipment, and finally the clean gas is discharged.

[0062] This utility model, through the collaborative design of multiple components, achieves efficient dust collection, convenient recycling, and long-term operation and maintenance of equipment during coal transportation, and has significant environmental and economic value.

[0063] The working principle of this invention is to achieve efficient dust collection and treatment in the coal transportation process through a synergistic process of negative pressure suction, multi-stage separation and filtration, dust recovery and clean exhaust. The specific process is as follows:

[0064] After the negative pressure dust collection fan is started, the retractable material guide cover 2 and the negative pressure dust collection cover 3 form a closed negative pressure chamber through flexible sealing. The dust generated when the material is dropped at the transfer node is sucked into the negative pressure dust collection cover 3 due to the negative pressure, thus achieving the initial collection of dust.

[0065] Large particle separation and recovery dust first enters the front-end separation equipment, where large particles with a diameter greater than 5-50mm are separated and directly discharged back to conveyor belt 1, avoiding large particles from entering subsequent pipelines and causing blockages or equipment wear.

[0066] Dust is collected and the remaining dust is returned to the dust collection trough with the airflow. The scraper or spiral return device at the bottom of the dust collection trough sends the dust back to the conveyor belt 1, realizing the recycling of dust.

[0067] If the dust contains moisture, the pipeline self-cleaning and airflow conveying system will activate to spray water (spraying water from nozzles every 2m) to prevent dust from adhering to the pipeline. Due to the inclined design of the pipeline (angle ≥0.2% - 0.5%), the sprayed mixture is discharged towards the separation equipment, ensuring unobstructed pipeline flow. The airflow continues to be conveyed to the vacuum dust collection unit.

[0068] After the exhaust airflow enters the vacuum dust collection unit, it passes through a primary filter for coarse filtration and a secondary cartridge filter for fine filtration to remove fine dust. Finally, the clean air is discharged into the atmosphere from the fan outlet. If pneumatic conveying of dust is required, the air discharged from the fan is used as the air source through PLC control to transport the powdery material to a designated location (such as a silo).

[0069] For the separation of water-containing dust, the airflow enters the water-water mixture separator. Through airflow deceleration, spraying and water seal devices, the water is separated from the water-water mixture and the gas. The solid collected material is discharged after sedimentation, and the gas containing water vapor enters the subsequent filtration process after demisting to ensure that the emitted gas is clean.

[0070] Example 1: Long-distance conveyor belt transfer system in open-pit coal mine

[0071] Open-pit coal mine conveyor belts can be several kilometers long, with many transfer nodes (such as the head, tail, and transfer points), large material drop (2-5m), dust easily spreads with the wind, and coal contains a lot of gangue, resulting in severe equipment wear.

[0072] 2. Telescopic material guide cover: It adopts a sleeve-type telescopic structure (telescopic range 0.5-3m) to adapt to different material drop differences at different transfer nodes; the wear-resistant lining of the inner wall is made of high chromium cast iron composite plate (thickness 10-15mm), which is resistant to gangue impact and wear, and its service life is increased to more than 3 times that of traditional rubber lining.

[0073] Negative pressure dust collection module: One dust collection module is set every 50-100m along the conveying path (8-12 in total). The negative pressure dust collection hood 3 of each module adopts a funnel-shaped enlarged design (diameter 1.2-1.5m) to increase the collection range; the flexible sealing component uses an aging-resistant canvas + steel wire skeleton structure to resist outdoor ultraviolet rays and wind and rain erosion.

[0074] Vacuum dust collection unit: Equipped with a dual-fan parallel system (single unit air volume 30000m³ / h) to ensure stable negative pressure (-500 to -800Pa) in long-distance pipelines (maximum 500m); The filter adopts a metal fiber filter cartridge (temperature resistant to 120℃), which is suitable for outdoor high-temperature environments and has a filtration efficiency of ≥99.9%.

[0075] Dust recovery device: The bottom of the dust collection trough is equipped with a scraper return device (chain speed 0.8m / s) to deal with possible dust agglomeration in the open environment; the scraper surface is coated with polytetrafluoroethylene to reduce adhesion.

[0076] Coal is conveyed to the transfer node via a long-distance conveyor belt 1. The retractable guide hood 2 is adjusted to a position 0.3-0.5m above the next-stage conveyor belt 1 according to the material drop height, reducing the space for dust diffusion. After the dual fans are started, the negative pressure chambers of each dust collection module form a closed negative pressure zone, and the dust generated by the material drop is forcibly sucked into the negative pressure dust collection hood 3. The dust-laden airflow is transported through pipelines to the front-end separation equipment, which separates gangue particles with a diameter >10mm and discharges them back to conveyor belt 1. The remaining dust enters the dust collection trough, and the scraper return device continuously sends the dust back to conveyor belt 1 for reuse. After the airflow is filtered by a metal fiber filter cartridge, the clean air is discharged into the atmosphere by the fan (dust emission concentration ≤10mg / m³). The system uses PLC linkage to control the start and stop of the fans in each module (only the transfer node module with material passing through is started), reducing energy consumption.

[0077] Outdoor environmental resistance: Wear-resistant lining and aging-resistant seals adapt to harsh weather, and dual fans ensure stable negative pressure over long distances;

[0078] Wear-resistant design: High-chromium cast iron lining and metal filter cartridge reduce damage to equipment from gangue.

[0079] Example 2: Short-distance conveying system for underground coal mines

[0080] Underground roadways are narrow (2-3m wide), with concentrated transfer points (such as from the coal face to the coal chute), high dust concentration (easily reaching 500mg / m³ or more), and the presence of flammable and explosive gases such as methane, requiring strict explosion-proof requirements for equipment.

[0081] Telescopic material guide cover 2: adopts a corrugated pipe compact structure (maximum telescopic range 1.5m), with the diameter reduced to 0.8-1m, suitable for narrow tunnels; the wear-resistant lining of the inner wall is made of flame-retardant rubber (thickness 5-8mm), which meets the requirements for underground fire prevention.

[0082] Negative pressure dust collection module: Dust collection modules are only set at 2-3 key transfer nodes. The negative pressure dust collection hood 3 adopts a side suction design (installed close to the tunnel wall) to reduce space occupation; the flexible sealing element is a flame-retardant canvas soft connection, which has passed the coal mine safety mark certification.

[0083] Vacuum dust collection unit: Explosion-proof fan (Ex dⅠ level), air volume 15000m³ / h, negative pressure -600Pa; filter adopts paper flame-retardant filter cartridge, filtration efficiency ≥99.8%, and can be quickly replaced (replacement time <5min).

[0084] Dust recovery device: The bottom of the dust collection tank adopts a spiral return device (0.3m in diameter), which has a compact structure and no exposed moving parts to avoid collision with underground equipment; wear-resistant welding rods are welded to the surface of the spiral blades to extend their service life.

[0085] Coal from the mining face is conveyed to the coal chute transfer point via a short-distance conveyor belt 1. The corrugated pipe guide hood retracts to its minimum spacing (0.2m) to reduce dust spillage. The explosion-proof fan starts, and the side-suction negative pressure dust collection hood 3 forms a negative pressure zone around the guide hood, drawing in high-concentration dust. The dust-laden airflow first passes through the front-end separation equipment (separating particles >5mm) and is then returned to conveyor belt 1. The remaining dust enters the dust collection trough, and the spiral return device spirally lifts the dust to the coal chute, preventing dust accumulation underground. After being filtered by a flame-retardant filter cartridge, the clean air (dust content ≤8mg / m³) is directly discharged into the roadway (no need to discharge to the surface). The system is linked to the underground gas sensor, automatically shutting down when the gas concentration >0.5% to ensure safety.

[0086] Explosion-proof and compact: Explosion-proof fans and flame-retardant materials meet underground safety standards, and the side-suction design and spiral return device are suitable for narrow spaces;

[0087] High-efficiency dust removal: The high negative pressure design quickly reduces high concentrations of dust underground, avoiding the risk of dust explosion.

[0088] Example 3: Port Coal Stockpile Conveying System

[0089] Coal in the port is conveyed to the stacker by conveyor belt 1. The drop height is large (3-8m) and the dust spreads quickly due to the influence of sea breeze. At the same time, the port environment is humid and dust is easy to stick to the pipes, so anti-clogging design is required.

[0090] Telescopic guide cover 2: adopts a multi-stage sleeve structure (telescopic range 2-6m) to adapt to the large drop changes when the stacker is raised and lowered; the inner wall wear-resistant lining is made of polyurethane elastomer (thickness 8mm), which has both wear resistance and anti-adhesion properties (damp dust does not easily adhere).

[0091] Negative pressure dust collection module: Two symmetrical dust collection modules (one on the left and one on the right) are set at the material drop point of the stacker. The negative pressure dust collection hood 3 is a ring-shaped enclosing structure (2m in diameter) that completely covers the material drop area. The flexible sealing parts are made of seawater corrosion resistant rubber to resist the salt spray erosion of the port.

[0092] Pipeline spray system: Enhanced design - One stainless steel nozzle is installed every 1.5m (more dense than usual), a small amount of surfactant is added to the spray water (to reduce dust stickiness); the pipeline inclination angle is increased to 0.8%, tilting towards the dust collection tank to accelerate the emission of moist dust.

[0093] Vacuum dust collection and recycling unit: fan air volume 40000m³ / h (to cope with sea wind interference), equipped with mud-water mixture separator (to handle wet dust); the bottom of the separator is equipped with a spiral mud discharge device to dehydrate the mud-water mixture (moisture content ≤30%) and send it back to the stockpile area.

[0094] Coal is conveyed to the stacker by conveyor belt 1. The telescopic guide hood 2 is adjusted to a distance of 0.5-1m from the stockpile as the stacker height changes. The annular negative pressure dust suction hood 3 is activated, creating a strong negative pressure zone (-800 to -1000Pa) in a sea breeze environment, sucking in all the dust (including moist particles) generated by the falling material. The dust-laden airflow first passes through the front-end separation equipment (separating coal pieces >20mm) and is then discharged back. The remaining dust enters the pipeline spray system, where spray nozzles wet the dust and prevent it from sticking. The moist dust flows into the dust collection trough through the inclined pipe. The mud-water mixture in the dust collection trough enters the separator, where solid dust (after dehydration) is separated by the airflow velocity and water seal device and sent back to the stockpile area by the spiral mud discharge device. The separated gas is then dehydrated by the demister and filtered through the filter cartridge, and the clean air is discharged into the atmosphere (emission concentration ≤5mg / m³).

[0095] Sea wind resistance and anti-adhesion: High-flow fan and ring-shaped dust hood resist sea wind diffusion, and dense spray and anti-corrosion design cope with humid and salt spray environment;

[0096] Moist dust treatment: The mud-water separator dehydrates and recycles moist dust, avoiding pipe blockage and resource waste.

[0097] In the description of this utility model, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In addition, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0098] The above description is only a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any modifications, equivalent substitutions and improvements made by those skilled in the art within the technical scope disclosed in this utility model, and within the spirit and principles of this utility model, should be included within the protection scope of this utility model.

Claims

1. A coal conveying dust control system, characterized in that, It includes conveyor belts, retractable guide hoods, negative pressure dust collection hoods, vacuum dust collection units, dust recovery devices, as well as front-end separation equipment and pipeline spraying systems; The retractable guide cover is installed at the coal transfer node to guide the coal falling; The retractable material guide cover is connected to the negative pressure dust collection cover through a flexible seal, and the two together form a closed negative pressure chamber. The outlet of the negative pressure dust collection hood of the dust recovery and return device is connected to the dust collection tank, and the bottom of the dust collection tank is equipped with a scraper return device or a spiral return device. The multi-module distributed dust collection structure system includes multiple dust collection modules, which are distributed at different transfer nodes along the coal conveying path to form a dust control network throughout the entire process, ensuring that there is no large-scale dust spillage during the entire coal conveying process. The front-end separation device is located between the negative pressure dust collection hood and the dust collection tank, and is used to separate particles with a diameter greater than 5-50mm; The duct spray system is installed on the duct between the negative pressure dust collection hood and the vacuum dust collection unit, with one duct nozzle every 2m of the duct; the vacuum dust collection unit is connected to the fan and includes a primary filter, a secondary cartridge filter and the fan.

2. The coal conveying dust control system as described in claim 1, characterized in that, The dust recovery device specifically includes: Mud-water mixture separator: After the mud-water mixture enters the separator, it uses airflow combined with spraying and water seal devices to separate the water and mud-water mixture from the gas. The solid material settles to the bottom and is discharged for collection. The gas containing some water vapor is demisted before entering the subsequent process. Terminal filtration equipment: performs fine filtration of gas to ensure that the discharged gas meets environmental protection requirements. If it is necessary to recover powdered materials, the materials can be transported to the designated location through the internal powder pneumatic conveying device.

3. The coal conveying dust control system as described in claim 1, characterized in that, The inner wall of the telescopic material guide cover is equipped with a wear-resistant lining, which is made of wear-resistant rubber or polymer wear-resistant sheet material and can withstand the impact and friction of coal falling.

4. The coal conveying dust control system as described in claim 1, characterized in that, The guide cover adopts a corrugated tube or sleeve telescopic structure, which can be flexibly adjusted according to the drop height to adapt to different working conditions.

5. The coal conveying dust control system as described in claim 1, characterized in that, The negative pressure chamber can completely contain the dust generated by the material feeding, preventing the dust from overflowing.

6. The coal conveying dust control system as described in claim 1, characterized in that, The scraper or spiral structure directly returns the collected dust to the conveyor belt, realizing the recycling of dust.

7. The coal conveying dust control system as described in claim 1, characterized in that, The front-end separation equipment is installed on the conveyor belt, and the separated large particles are directly discharged to the conveyor belt to avoid large particles entering the subsequent pipelines and causing blockages or excessive wear on the equipment.

8. The coal conveying dust control system as described in claim 1, characterized in that, When collecting mud-water mixtures or water-containing dust, the nozzles spray water to prevent dust from adhering to the inner wall of the pipe; the pipe inclination angle of the pipe spraying system is not less than 0.2% - 0.5%, and it is inclined towards the front-end separation equipment.

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