Centrifugal gas-free dry fog dust suppression system for port coal yard

Abstract

The application discloses a centrifugal airless dry fog dust suppression system for a port coal yard, and belongs to the technical field of dust treatment of bulk cargo loading and unloading, storage and transportation in a port. The system comprises a centrifugal atomization nozzle array, a water supply pipeline, a power supply circuit and a dust concentration monitoring and linkage control module; the centrifugal atomization nozzle array is dispersedly arranged in each dust raising target area by a plurality of nozzles; the system does not contain compressed air source equipment and a gas supply pipeline; the centrifugal atomization nozzle comprises a driving motor and a centrifugal atomization disc, and the atomization and breaking of water is realized by mechanical centrifugal force generated by rotation of the centrifugal atomization disc. The application replaces compressed air with a motor-driven centrifugal atomization disc pure mechanical force atomization, and only needs a water supply pipeline and a power supply circuit to operate, so that the system architecture is simplified and energy consumption is greatly reduced; dust suppression is realized by partition and on-demand through linkage of a PLC and a dust sensor, and the comprehensive water saving rate reaches 60% to 75%. The application is suitable for dry fog dust suppression operation of a coal yard in a port coal transfer base.

Description

Technical Field

[0001] This invention belongs to the field of dust control technology in the process of loading, unloading, storage and transportation of bulk cargo in ports. Specifically, it relates to a dry fog dust suppression system applied to the coal yard of a port coal transshipment base, and in particular, an ultra-fine dry fog dust suppression system that uses centrifugal atomizing nozzles to achieve dust suppression without the need for compressed air source. Background Technology

[0002] Port coal transshipment bases are crucial nodes in the transportation of coal from ships to land. During the storage, handling, transfer, and loading / unloading of coal, large amounts of dust are generated due to wind and mechanical disturbance. Coal dust not only causes material loss and affects surrounding air quality, but its fine particles (PM2.5–PM10) pose a significant health hazard to the human respiratory system once they enter the atmosphere. Furthermore, coal dust poses an explosion risk at certain concentrations. With the continuous tightening of national standards for port air pollutant emissions, efficient dust suppression at coal yards has become a rigid requirement for port operations.

[0003] Currently, the dust suppression technologies widely used in port coal yards and similar bulk material storage yards mainly fall into the following categories:

[0004] Dust suppression methods include water spraying and mist cannons. These methods involve spraying water mist onto dusty areas using high-pressure water guns or mist cannons, relying on the water droplets to collide with and combine with coal dust, increasing their weight and causing them to settle. However, these methods generally result in large droplet sizes (typically above 100μm), which are incompatible with the size of fine coal dust (PM2.5–PM10), leading to low collision and combination efficiency and limited dust suppression effects. Furthermore, they consume a large amount of water, and excessive water spraying increases the moisture content of the coal, affecting its calorific value and increasing the risk of icing in northern winters. Mist cannons also require high-powered fans to propel the water mist, resulting in high energy consumption and noise levels.

[0005] Two-phase flow dry fog dust suppression systems, such as the ship loader dry fog dust suppression system disclosed in CN111422642A, the coal conveyor belt dry fog dust suppression device disclosed in CN203486517U, and the intelligent dry fog dust suppression equipment disclosed in CN205730729U, utilize compressed air and water to mix and impact within specialized nozzles, breaking the water into fine mist droplets of 1–10 μm, thus achieving efficient capture of fine coal dust. However, such solutions rely on air compressor stations, air storage tanks, and air supply pipelines, resulting in large and complex systems with high initial investment, high air compressor energy consumption (typically accounting for over 60% of the total system energy consumption), and the air supply pipelines are prone to corrosion, leakage, and blockage when laid over long distances in open-air locations in port coal yards, leading to a large maintenance workload.

[0006] Ultrasonic dry fog dust suppression systems. For example, CN113318545A discloses a high-efficiency dry fog dust suppression device based on high-frequency sound waves, which atomizes water into 1-10μm micro-mist using sound wave energy. While these systems offer good atomization, the ultrasonic transducers have a small individual coverage area and are expensive (costing tens of thousands to hundreds of thousands of yuan per unit). This makes them uneconomical for large-scale, multi-site applications in coal yards, and they are currently only used in scenarios where cost is not a primary concern, such as iron and steel plant ore powder stockpiles.

[0007] Centrifugal atomization dust suppression technology. For example, CN105344505B discloses a centrifugal collision-type dust suppression nozzle for mining, which uses a spiral centrifugal channel to accelerate water flow before collision and atomization, specifically designed for underground coal mining faces. Its centrifugal atomization mechanism is a spiral collision type (not a rotating disk shearing type), and it is only designed for single-point application in narrow underground spaces, not for large-scale systematic dust suppression solutions in open-pit coal yards.

[0008] While spraying devices with centrifugal atomizing discs as core components exist in the agricultural plant protection field (such as CN115889014A and CN108480076A), their design is based on intermittent operation conditions of UAV platforms (single flight time of approximately 10-15 minutes). They do not provide any technical inspiration or solutions for all-weather industrial-grade dust suppression operations in port coal yards, regarding the continuous operational reliability of core components, sealing and heat dissipation in high-dust environments, or array-style deployment architecture for large-area stockpiles. There is no systematic technical solution in the existing technology for adapting the aforementioned centrifugal atomizing nozzles to continuous industrial operation for dry fog dust suppression in port coal yards. Summary of the Invention

[0009] The purpose of this invention is to provide a method and system for predicting the remaining useful life of cross-domain machines based on dual-path degradation consistency constraints, so as to solve the above-mentioned technical problems.

[0010] The technical solution provided by this invention is: a centrifugal, airless dry fog dust suppression system for port coal yards, the system comprising: a centrifugal atomizing nozzle array, a water supply pipeline, a power supply line, and a dust concentration monitoring and linkage control module.

[0011] The centrifugal atomizing nozzle array consists of multiple centrifugal atomizing nozzles, and each centrifugal atomizing nozzle is dispersed in various dust-generating target areas of the port coal yard.

[0012] The water supply pipeline is connected to each of the centrifugal atomizing nozzles and is used to supply atomizing water to each of the centrifugal atomizing nozzles;

[0013] The power supply line is electrically connected to each of the centrifugal atomizing nozzles and is used to supply power to each of the centrifugal atomizing nozzles;

[0014] The dust concentration monitoring and linkage control module includes multiple dust concentration sensors and a PLC controller. The multiple dust concentration sensors are respectively deployed in each dust target area, which includes the material discharge area of ​​the conveyor belt, the operation area of ​​the stacker-reclaimer, and the area surrounding the coal stack. The PLC controller is connected to each of the dust concentration sensors and each of the centrifugal atomizing nozzles, and is used to independently control the start, stop, and speed of each centrifugal atomizing nozzle in the corresponding area according to the detection signal of the dust concentration sensor in each dust target area.

[0015] The system consists of a water supply pipeline and a power supply line, forming the working medium and power supply architecture. The system does not contain compressed air source equipment or air supply pipeline.

[0016] The centrifugal atomizing nozzle includes a drive motor and a centrifugal atomizing disc. The drive motor drives the centrifugal atomizing disc to rotate, shearing and breaking the water into droplets. The atomization and breaking of the water is achieved solely by the mechanical centrifugal force generated by the rotation of the centrifugal atomizing disc.

[0017] Preferably, the centrifugal atomizing nozzle further includes:

[0018] An impeller pump, coaxially mounted on the shaft of the drive motor, is used to pressurize low-pressure water from the water supply pipeline and deliver it to the central inlet of the centrifugal atomizing disc.

[0019] The centrifugal atomizing disc is coaxially mounted on the upper end of the drive motor shaft, and the upper surface of the centrifugal atomizing disc is provided with microgrooves and / or tooth-like structures radiating outward from the center.

[0020] A flow guide is placed above the centrifugal atomizing disc to control the spray diffusion angle.

[0021] Preferably, the drive motor is an external rotor brushless DC motor with a rated speed range of 5000-12000 rpm and a protection level of not less than IP65; the centrifugal atomizing disc is made of stainless steel or titanium alloy with a diameter range of 40-80 mm and a wear-resistant and anti-scaling coating on its surface; the droplet size generated by the centrifugal atomizing disc under the drive motor is 10-30 μm; the spray diffusion angle controlled by the guide hood is 30°-90°, and the effective coverage radius is 3-8 m.

[0022] Preferably, the water supply pipeline includes a main water supply pipe and multiple branch water supply pipes, and each centrifugal atomizing nozzle is connected to the main water supply pipe through each branch water supply pipe; the power supply line includes a main power supply line and multiple branch power supply lines, and each centrifugal atomizing nozzle is electrically connected to the main power supply line through each branch power supply line; the front end of the main water supply pipe is provided with a precision filter with a filtration accuracy of not less than 50 μm.

[0023] Preferably, the centrifugal atomizing nozzle array is arranged in zones as follows:

[0024] Conveyor belt discharge port area: The centrifugal atomizing nozzles are installed above and on both sides of the discharge port through fixed brackets, with the spray direction facing the dust-generating area of ​​the coal flow discharge. 2 to 6 nozzles are arranged at each location.

[0025] Stacker-reclaimer area: The centrifugal atomizing nozzles are fixed to the stacker-reclaimer cantilever or bucket wheel mechanism by a follow-up mounting bracket, and move with the stacker-reclaimer during operation. Each stacker-reclaimer is equipped with 4 to 12 nozzles.

[0026] Coal stacking area: The centrifugal atomizing nozzles are arranged around the stack at intervals of 8 to 15 m via follow-up mounting brackets. The height of the lifting brackets is adjustable from 2 to 10 m, and the nozzle installation angle is adjustable.

[0027] Preferably, the dust concentration sensors are PM2.5 and PM10 dust concentration sensors, which are respectively deployed in each of the dust-generating target areas; each dust-generating target area is equipped with a solenoid valve at the front end of the water supply branch pipe, which is connected to the PLC controller and controlled by the PLC controller to achieve independent water supply to each zone; according to the detection signals of the dust concentration sensors in each zone, when the dust concentration in any zone exceeds a preset threshold, the PLC controller automatically turns on the centrifugal atomizing nozzle group corresponding to that zone, and adjusts the speed of the drive motor according to the dust concentration level to change the atomization amount.

[0028] Preferably, the system further includes an antifreeze heat tracing module, which includes: a self-regulating heating cable laid along the water supply pipeline, an electric heating ring disposed on the centrifugal atomizing nozzle housing, and a temperature sensor; the temperature sensor, the self-regulating heating cable, and the electric heating ring are respectively connected to the PLC controller via signal connection; when the ambient temperature is below 2°C, the PLC controller automatically starts the heat tracing; when the ambient temperature is above 5°C, the heat tracing automatically stops; the system also includes a drain valve, which is connected to the PLC controller via signal connection, for draining the water accumulated in the pipeline and nozzle when the system is not in use for a long period of time.

[0029] Preferably, the water supply pipeline is also connected in parallel to a dust suppressant mixing and injection device, which is used to inject a wetting agent or a crusting dust suppressant into the atomizing water at a volume ratio of 0.1% to 1.0%.

[0030] The present invention also provides a dust suppression method for the aforementioned centrifugal dry fog dust suppression system for port coal yards, comprising the following steps:

[0031] The concentrations of PM2.5 and PM10 in the air are detected in real time by dust concentration sensors deployed in various dust-prone areas;

[0032] The PLC controller receives the detection signals from each of the dust concentration sensors and compares the detection values ​​with preset thresholds.

[0033] When the dust concentration in any area exceeds the preset threshold, the PLC controller controls the solenoid valve corresponding to that area to open, and at the same time starts the centrifugal atomizing nozzle group corresponding to that area. The centrifugal atomizing disc is driven by the drive motor to rotate and shear and break the water into droplets for dust suppression spraying.

[0034] The PLC controller adjusts the speed of the drive motor according to the dust concentration level to adjust the atomization amount. The higher the dust concentration, the higher the motor speed is controlled to increase the atomization amount.

[0035] When the dust concentration drops below the safety threshold, the PLC controller controls the solenoid valve to close and stop the centrifugal atomizing nozzle group in that area;

[0036] The preset threshold is a PM10 concentration ≥ 150 μg / m³. 3 The safety threshold is PM10 concentration ≤ 120 μg / m³. 3 .

[0037] Preferably, the system also includes an antifreeze control step: a temperature sensor detects the ambient temperature in real time and feeds it back to the PLC controller; when the ambient temperature is below 2°C, the PLC controller automatically starts the self-regulating electric heating tape laid along the water supply pipeline and the electric heating ring of the nozzle housing for heating; when the ambient temperature is above 5°C, the heating is automatically stopped; when the system is shut down, the PLC controller controls the drain valve to open and drain the water accumulated in the pipeline and nozzle.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] (1) The system architecture is simplified, eliminating dependence on gas supply.

[0040] This invention utilizes a centrifugal atomizing disc driven by an electric motor for pure mechanical atomization, eliminating the need for compressed air assistance. The system does not require an air compressor station, air tank, or air supply pipeline; it only requires a water supply pipeline and a power supply line to operate. Compared to two-phase flow dry fog dust suppression systems, it eliminates the need for air compressor station construction and the laying and maintenance of long-distance air supply pipelines, reducing the number of devices by more than 60% and lowering infrastructure investment by 40% to 60%.

[0041] (2) Operating energy consumption is significantly reduced.

[0042] Traditional gas-water two-phase flow system (covering 5000 m) 2The power consumption of an air compressor is about 30-55 kW, accounting for 60%-80% of the total energy consumption; the power of a single nozzle of this invention is only 100-300 W, and the total power consumption of 20 nozzles covering the same area is only 2-6 kW, saving 80%-90% of energy and improving the energy efficiency ratio by 4-8 times.

[0043] (3) Distributed arrays improve reliability and coverage flexibility.

[0044] Multiple small nozzles are distributed close to the dust source, resulting in a short collision path between the droplets and coal dust, achieving a dust suppression efficiency of over 90%. Single-point failures only affect localized areas, making the system more reliable than centralized solutions.

[0045] (4) Intelligent linkage control enables dust suppression on demand.

[0046] The dust sensor is linked with the PLC for zoned operation, automatically activating the nozzle group only in areas where dust exceeds the standard, and adjusting the motor speed in real time according to the dust concentration to match the atomization amount, achieving a comprehensive water saving rate of 60% to 75%, and avoiding excessive spraying that would increase the moisture content of the coal.

[0047] (5) Winter protection against freezing is applicable year-round.

[0048] The system is linked with a self-regulating heating cable, an electric heating ring, and a temperature sensor, and automatically drains water when the system stops, ensuring normal operation at -20℃. Attached Figure Description

[0049] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0050] Figure 1 The overall architecture diagram of the centrifugal, airless dry fog dust suppression system for port coal yards provided by the present invention;

[0051] Figure 2 This invention provides a schematic diagram of the internal structure and atomization principle of the centrifugal atomizing nozzle.

[0052] Figure 3 This is a schematic diagram of the nozzle layout for the centrifugal, airless dry fog dust suppression system for port coal yards provided by the present invention, wherein:

[0053] (a) is a schematic diagram of the material drop-out port layout of the transfer belt;

[0054] (b) is a schematic diagram of the stacker-reclaimer follow-up deployment;

[0055] (c) is a schematic diagram of the layout around the coal pile;

[0056] (d) is a schematic diagram of dust monitoring and zone control. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0058] like Figure 1 As shown, the present invention provides a centrifugal dry fog dust suppression system for port coal yards, including a centrifugal atomizing nozzle array, a water supply pipeline, a power supply line, and a dust concentration monitoring and linkage control module.

[0059] The centrifugal atomizing nozzle array consists of multiple centrifugal atomizing nozzles, which are distributed in various dust-generating target areas of the port coal yard. The dust-generating target areas include the material discharge area of ​​the conveyor belt, the stacker-reclaimer operating area, and the area surrounding the coal stack.

[0060] The water supply pipeline consists of a main water supply pipe and multiple branch water supply pipes. Each centrifugal atomizing nozzle is connected to the main water supply pipe through a branch water supply pipe. The inlet pressure of the main water supply pipe is 0.1–0.3 MPa, supplied by the municipal water supply network or the site's greywater reuse pumping station, eliminating the need for a booster pumping station. A precision filter is installed at the front end of the main water supply pipe, with a filtration accuracy of no less than 50 μm, preferably a 200-mesh (approximately 75 μm) self-cleaning backwash filter, to prevent coal dust particles from entering the nozzles and clogging the microgrooves of the centrifugal atomizing disc. A self-regulating heating cable is laid along the main water supply pipe for winter freeze protection.

[0061] The power supply line consists of a main power supply line and multiple branch power supply lines. Each centrifugal atomizing nozzle is electrically connected to the main power supply line via its respective branch power supply line. The main power supply line uses a 380V three-phase four-wire system, and each nozzle's branch power supply line is connected to a single-phase 220V line.

[0062] The dust concentration monitoring and linkage control module includes multiple dust concentration sensors and a PLC programmable logic controller. The multiple dust concentration sensors are deployed in each dust-generating target area, specifically PM2.5 and PM10 dust concentration sensors. They are installed at the dust source (directly above the material discharge port, beside the stacker-reclaimer bucket wheel, and downwind of the coal pile) and along the downwind diffusion path. The sensors are installed at a height of 3–8 m above the ground, with a horizontal spacing of no more than 20 m. The PLC controller is connected to each dust concentration sensor and each centrifugal atomizing nozzle, and independently controls the start / stop and rotation speed of each centrifugal atomizing nozzle in the corresponding dust-generating target area based on the detection signals from the dust concentration sensors.

[0063] The core feature of this invention is that the system consists of a water supply pipeline and a power supply line forming the working medium and power supply architecture. The system does not contain compressed air source equipment or supply pipelines, and does not include an air compressor station, air storage tank, or any form of air supply pipeline. The atomization and fragmentation of water are achieved solely by the mechanical centrifugal force generated by the rotation of a centrifugal atomizing disc.

[0064] like Figure 2 As shown, the centrifugal atomizing nozzle includes the following components:

[0065] Drive motor: The drive motor adopts an external rotor brushless DC motor with a rated speed range of 5000~12000rpm and a protection level of not less than IP65 to adapt to the high dust and high humidity environment of the coal yard. The external rotor structure allows the centrifugal atomizing disc to be directly installed on the upper end of the motor shaft without the need for an additional transmission mechanism, reducing energy transmission loss and improving system reliability.

[0066] The impeller pump is a centrifugal miniature impeller pump, coaxially mounted on the drive motor shaft. The impeller of the impeller pump rotates synchronously with the motor shaft, pressurizing the low-pressure water (supply pressure 0.1–0.3 MPa) from the water supply pipeline and delivering it to the central inlet of the centrifugal atomizing disc. The coaxial mounting design of the impeller pump and drive motor allows the nozzle to simultaneously drive the atomizing disc rotation and impeller pump pressurization with only one power supply, eliminating the need for an external high-pressure water supply pump station and further simplifying the system architecture.

[0067] The centrifugal atomizing disc is coaxially mounted on the upper end of the drive motor shaft. It is made of stainless steel or titanium alloy and the surface is treated with a wear-resistant and anti-scaling coating. The diameter of the centrifugal atomizing disc ranges from 40 to 80 mm.

[0068] The upper surface of the centrifugal atomizing disc is provided with a microgroove structure radiating outward from the center. The specific parameters of the microgrooves are as follows: Number of grooves: 24–72, evenly distributed along the circumference; Groove depth: 0.1–0.5 mm; Groove width: 0.2–1.0 mm (groove bottom width), with a top opening width of 0.3–1.5 mm, forming a trapezoidal cross-section that is wider at the top and narrower at the bottom; Groove orientation: extending radially in straight lines from the liquid inlet at the center of the centrifugal atomizing disc outward, or extending in a slightly curved arc (the arc curvature is opposite to the rotation direction to increase the residence time and shearing frequency of the liquid within the groove); Groove cross-sectional shape: trapezoidal, rectangular, or V-shaped, with a trapezoidal cross-section preferred to balance liquid constraint and smooth detachment.

[0069] The mechanism by which microgrooves affect atomized particle size is as follows: When water is pumped by an impeller pump to the central inlet of the centrifugal atomizing disk, it flows outward along the radial microgrooves under centrifugal force. The depth and width of the microgrooves determine the thickness of the liquid film; the shallower and narrower the grooves, the thinner the liquid film, and the smaller the droplet size produced after shearing and breaking at the same rotational speed. The number and distribution density of the grooves affect the uniformity of liquid film distribution; the more grooves and the more uniform their distribution, the more consistent the thickness of the liquid film in all radial directions on the disk surface, and the more concentrated the droplet size distribution (the smaller the particle size spectrum). The cross-sectional shape of the grooves affects the flow resistance and escape angle of the liquid within the grooves. A trapezoidal cross-section can balance the liquid's constraint ability and escape smoothness during high-speed rotation, preventing liquid accumulation or premature escape within the grooves, which would lead to uneven atomization. When the drive motor drives the centrifugal atomizing disk to rotate at a speed of 5000 to 12000 rpm, water forms an extremely thin liquid film under the constraint of the micro-grooves. Under the action of centrifugal force, it is thrown outward along the grooves and sheared and broken into ultrafine dry fog with a droplet size of 10 to 30 μm at the edge of the disk.

[0070] The guide hood, positioned above the centrifugal atomizing disk, is a ring-shaped or conical structure used to guide droplets to diffuse in a predetermined direction. The inner wall of the guide hood is a smooth curved surface, allowing control of the spray diffusion angle from 30° to 90°, with an effective coverage radius of 3 to 8 m. The spray diffusion angle is adjusted by changing the guide hood's relative position to the centrifugal atomizing disk (axial distance and radial envelope angle). The closer the guide hood is to the edge of the atomizing disk and the larger the envelope angle, the smaller the spray diffusion angle and the stronger the spray directionality; conversely, the farther away the guide hood is from the atomizing disk, the larger the diffusion angle and the wider the coverage area.

[0071] The nozzle housing is a sealed structure with a protection rating of at least IP65, housing the drive motor, impeller pump, and lower part of the centrifugal atomizing disc. The nozzle housing is equipped with an electric heating ring for winter freeze protection. The top of the nozzle housing is open, exposing the upper surface of the centrifugal atomizing disc and the guide shield for outward spraying of droplets.

[0072] like Figure 3 As shown, the centrifugal atomizing nozzle array is arranged in the following sections, and the corresponding support structure for each arrangement is as follows:

[0073] Centrifugal atomizing nozzles in the conveyor belt discharge area are installed above and to the sides of the discharge port using fixed brackets. The fixed brackets consist of a mounting base, uprights, and a crossbeam. The mounting base is fixed to the surrounding steel structure or concrete foundation using anchor bolts or welding. The uprights are vertically fixed to the mounting base, with the height determined according to the discharge port size (typically 1.5–3 m). The crossbeam is horizontally fixed to the top of the uprights, and a nozzle mounting seat is provided on the crossbeam. The centrifugal atomizing nozzles are fixed to the crossbeam via the nozzle mounting seats, with the spray direction directed towards the dust-generating area of ​​the coal flow. Two to six nozzles are installed at each discharge port, distributed above and to the sides, forming a multi-angle, enveloping spray coverage of the dust source.

[0074] The centrifugal atomizing nozzles in the stacker-reclaimer area are fixed to the stacker-reclaimer cantilever or bucket wheel mechanism by mounting brackets and move with the stacker-reclaimer during operation.

[0075] The specific structure of the mounting bracket includes: a fixed base, a connecting arm, and a nozzle mounting plate.

[0076] The mounting base is a U-shaped or L-shaped metal component, fixed to the lower or side surface of the stacker-reclaimer cantilever (or the support frame of the bucket wheel mechanism) by bolts or welding. The mounting base is equipped with reinforcing ribs to improve structural rigidity and adapt to the vibration conditions during stacker-reclaimer operation.

[0077] The connecting arm is a metal rod or pipe, with one end fixedly connected to the mounting base (by welding or bolting), and the other end extending outward or downward from the cantilever to extend the nozzle installation position to the dust-generating area outside the cantilever. The length of the connecting arm is determined according to the cantilever width and the position of the bucket wheel, and is typically 0.5 to 2 m.

[0078] The nozzle mounting plate, a flat component, is fixed to the end of the connecting arm and features nozzle mounting holes and an angle adjustment slot. The centrifugal atomizing nozzle is bolted into the nozzle mounting hole or angle adjustment slot and fixedly connected to the nozzle mounting plate. The angle adjustment slot is an arc-shaped groove, allowing the nozzle mounting angle to be adjusted within a certain range (e.g., 0°–45°) to ensure the spray direction is aligned with or slightly downwards from the coal flow direction.

[0079] The fixed base, connecting arm, and nozzle mounting plate move synchronously with the cantilever pitch and rotation of the stacker-reclaimer, ensuring that the nozzles always follow the stacker-reclaimer's operating position for dynamic dust suppression. Each stacker-reclaimer is equipped with 4 to 12 nozzles, spaced apart along the cantilever length to cover the entire dust-generating area.

[0080] Centrifugal atomizing nozzles in the coal stack area are arranged at intervals of 8 to 15 m along the perimeter of the stack via height-adjustable supports.

[0081] The height-adjustable bracket has the following structure: base, outer sleeve, inner sleeve, locking mechanism, and nozzle mounting base.

[0082] The base is a round or square metal plate, which is fixed to the ground by anchor bolts or a concrete foundation. The upper surface of the base is equipped with reinforcing ribs to improve its load-bearing capacity.

[0083] The outer sleeve is a vertically arranged hollow metal tube, with its lower end fixedly connected to the base (by welding or flange connection). The inner diameter of the outer sleeve is adapted to the outer diameter of the inner sleeve, and the inner sleeve can be slidably fitted inside the outer sleeve. The outer sleeve has multiple sets of positioning holes spaced apart along the axial direction (hole diameter 10-16 mm, spacing between adjacent positioning holes 100-200 mm).

[0084] The inner sleeve is a hollow metal tube coaxially arranged with the outer sleeve, with an outer diameter slightly smaller than the inner diameter of the outer sleeve (gap 0.5–2 mm), allowing it to slide freely axially within the outer sleeve. The inner sleeve has adjustment holes (same diameter as the positioning holes, same spacing as the outer sleeve) corresponding to the positioning holes of the outer sleeve. By sliding the inner sleeve to different heights within the outer sleeve, the adjustment holes of the inner sleeve are aligned with the corresponding positioning holes of the outer sleeve, and a locking pin (stop pin) is inserted to achieve relative fixation between the inner and outer sleeves.

[0085] The locking mechanism is a locking pin (stop pin), which passes through the positioning hole of the outer sleeve and the adjustment hole of the inner sleeve, locking the inner sleeve at the set height position of the outer sleeve. Preferably, the locking pin is a spring pin or a quick-release pin, which facilitates quick height adjustment.

[0086] The nozzle mounting base is fixed to the top of the inner sleeve and is a U-shaped or L-shaped metal component with nozzle mounting holes and an angle adjustment structure. The centrifugal atomizing nozzle is bolted to the nozzle mounting base, and the nozzle mounting angle can be adjusted via the angle adjustment structure (adjustment range 0°~90°) to ensure that the spray diffusion angle covers the top and side slopes of the stack.

[0087] The height of the height-adjustable bracket is adjustable from 2 to 10 m. Depending on the height of the coal pile (which is usually 8 to 15 m), the nozzle can be adjusted to be level with or slightly higher than the top of the pile to ensure that the spray can effectively cover the surface of the pile.

[0088] Preferably, a dustproof sealing ring is provided between the outer sleeve and the inner sleeve to prevent coal dust from entering the sleeve gap and affecting the sliding fit.

[0089] In this invention, the droplet size generated by the centrifugal atomizing disc is 10–30 μm. It is well known in the art that "dry fog" typically refers to fine water mist particles with a diameter of less than 10 μm. The choice of a droplet size range of 10–30 μm in this invention is a technical trade-off based on the specific needs of dust suppression applications in port coal yards, for the following reasons:

[0090] While theoretically, the collision and agglomeration efficiency is highest when water mist particles and dust particles are similar in size, dust in port coal yards contains not only fine particles of PM2.5 (≤2.5 μm) and PM10 (≤10 μm), but also a large number of larger particles of 10–50 μm. Data from the embodiments of this invention show that droplet sizes of 10–30 μm achieve a dust suppression efficiency of 88%–94% for PM10 and over 87% for PM2.5. This efficiency level is essentially equivalent to 85%–95% for air-water two-phase flow dry fog systems (1–10 μm) and 90%–96% for ultrasonic dry fog systems (1–10 μm), fully meeting the environmental emission standards for port coal yards.

[0091] Dry fog particles smaller than 10 μm are easily drifted by natural crosswinds in open-air environments. Port coal yards are open-air environments, constantly affected by sea breezes or monsoons. Fine fog droplets of 1–10 μm are easily blown away from the target area by wind, resulting in a significant reduction in the effective fog volume reaching the dust source and diminishing the dust suppression effect. In contrast, fog droplets of 10–30 μm have greater mass and kinetic energy, significantly enhancing their resistance to wind drift and enabling them to settle more accurately at the dust source.

[0092] The larger the droplet size, the faster the settling velocity under gravity. Droplets of 10–30 μm have a faster settling velocity than dry fog of 1–10 μm, enabling them to reach the surface of coal dust particles more quickly and complete collision and agglomeration, reducing the suspension time of droplets in the air and improving the dust suppression efficiency per unit volume of water.

[0093] The design droplet size range of the centrifugal atomizing nozzle for agricultural plant protection is 15–50 μm. This invention extends the lower limit of the droplet size to 10 μm by increasing the motor speed (5000–12000 rpm) and optimizing the microgroove structure, which is close to the limit of fine atomization under this technical approach. Further pursuing a droplet size of 1–10 μm would require a significant increase in the motor speed or a change in the atomization mechanism (such as using gas-water two-phase flow or ultrasound), which would negate the core advantage of this invention: "no air source, low energy consumption".

[0094] In summary, the present invention selects a droplet size range of 10–30 μm, which is the optimal balance between dust suppression efficiency, anti-drift capability, settling velocity and system energy consumption. It is a targeted design for special working conditions such as open-air, windy, and large-area coal yards in ports.

[0095] The specific control logic of the dust concentration monitoring and linkage control module is as follows:

[0096] PM2.5 and PM10 dust concentration sensors deployed in each dust-prone target area monitor the dust concentration in the air in real time and transmit the detection signals to the PLC controller. Each zone's water supply branch pipe is equipped with a solenoid valve, which is connected to the PLC controller and controlled by the PLC controller to achieve independent water supply to each zone.

[0097] The PLC controller has a preset dust concentration threshold (e.g., PM10 concentration ≥ 150 μg / m³). 3 The threshold for activation is PM10 concentration ≤ 120 μg / m³. 3(This is a stop threshold). When the PLC controller detects that the dust concentration in any dust-generating target area exceeds the preset start threshold, it automatically opens the solenoid valve corresponding to that area and simultaneously starts the centrifugal atomizing nozzle group corresponding to that area. The controller then adjusts the nozzle motor speed via a variable frequency speed control module according to the dust concentration level to change the atomization volume—the higher the dust concentration, the higher the motor speed is controlled to increase the atomization volume. Specifically, when the dust concentration is between 150 and 300 μg / m³... 3 At that time, the motor ran at 8000 rpm (full fog volume); 150~180 μg / m 3 The flow rate decreased to 6000 rpm (medium mist); 120–150 μg / m 3 The speed is reduced to 4000 rpm (low mist volume maintenance). When the dust concentration drops below the stop threshold, the PLC controller controls the solenoid valve to close and stop the centrifugal atomizing nozzle assembly in that area.

[0098] The present invention also includes an antifreeze heat tracing module, the specific structure and control logic of which are as follows:

[0099] Self-regulating electric heating tape (power density 20-30 W / m) is laid along the main water supply pipe and each branch water supply pipe. Each centrifugal atomizing nozzle housing has a built-in electric heating ring (power 20-50 W). Temperature sensors are installed in each dust-generating target area to detect the ambient temperature in real time and feed it back to the PLC controller.

[0100] When the temperature sensor detects that the ambient temperature is below 2℃, the PLC controller automatically starts the corresponding area's electric heating cable and nozzle heating ring for heat tracing; when the ambient temperature is above 5℃, it automatically stops heat tracing. The self-regulating electric heating cable has the characteristic of automatically reducing its heating power as the temperature rises, and can automatically adjust the heat output within the set temperature range, eliminating the need for an additional temperature controller.

[0101] The system is also equipped with drain valves, which are installed at the lowest point of the main water supply pipe and at the end of each branch water supply pipe, and are connected to the PLC controller. When the system is not in use for a long period of time, the PLC controller controls the drain valves to open, using gravity to drain the water accumulated in the pipes and nozzles, preventing static freezing.

[0102] As a further improvement to the technical solution, a dust suppressant mixing and injection device is also connected in parallel to the water supply pipeline, including a dust suppressant storage tank, a metering pump, and a mixer. The dust suppressant storage tank is used to store wetting agents or crusting dust suppressants. The metering pump is connected to the PLC controller and pumps the dust suppressant from the storage tank according to the set ratio. After mixing with water in the main water supply pipe through the mixer, the mixture enters each branch water supply pipe. The volume ratio of the injected dust suppressant ranges from 0.1% to 1.0%, and is used to enhance the dust suppression effect under specific coal types (such as low-rank coal and high-volatile coal) or extreme dust conditions (such as windy weather and high-flow loading and unloading operations).

[0103] The dust suppression method of the centrifugal dry fog dust suppression system for port coal yards provided by the present invention includes the following steps:

[0104] Step 1: Real-time dust concentration detection; The concentrations of PM2.5 and PM10 in the air are detected in real time by dust concentration sensors deployed in each dust-generating target area.

[0105] Step Two: Signal Comparison and Judgment; The PLC controller receives the detection signals from each dust concentration sensor and compares the detected values ​​with a preset threshold (PM10 concentration ≥ 150 μg / m³). 3 (Compare)

[0106] Step 3: Zoned Spraying Start; When the dust concentration in any zone exceeds the preset threshold, the PLC controller controls the corresponding solenoid valve to open, simultaneously activating the corresponding centrifugal atomizing nozzle group. Water, after being filtered by a precision filter, enters the main water supply pipe, and is distributed to the branch water supply pipes via the zone solenoid valves, eventually entering the centrifugal atomizing nozzles. The impeller pump inside the nozzle pressurizes the low-pressure water and delivers it to the central inlet of the centrifugal atomizing disc. The drive motor drives the centrifugal atomizing disc to rotate at high speed. Under the constraint of the micro-grooves, the water forms an extremely thin liquid film, which, under centrifugal force, is thrown outwards along the grooves and sheared and broken into ultrafine dry mist of 10–30 μm at the disc edge. Guided by the guide hood, this mist is sprayed towards the dust-generating area.

[0107] Step 4: Adjust the mist volume using frequency conversion speed control. The PLC controller adjusts the speed of the drive motor according to the dust concentration level through the frequency conversion speed control module to adjust the atomization volume. The higher the dust concentration, the higher the motor speed is controlled to increase the atomization volume, and vice versa.

[0108] Step 5: Stop spraying; when the dust concentration drops to the safe threshold (PM10 concentration ≤ 120 μg / m³) 3 When the following conditions are met, the PLC controller controls the solenoid valve to close and stop the centrifugal atomizing nozzle assembly in that area.

[0109] The system also includes an anti-freeze control mechanism: a temperature sensor monitors the ambient temperature in real time and feeds it back to the PLC controller. When the ambient temperature is below 2°C, the PLC controller automatically activates the self-regulating electric heating tape laid along the water supply pipeline and the electric heating ring on the nozzle housing to provide heat tracing, preventing the pipeline and nozzles from freezing; when the ambient temperature is above 5°C, the heating automatically stops. When the system is not in use, the PLC controller controls the drain valve to open, emptying the water accumulated in the pipeline and nozzles.

[0110] Example 1

[0111] This embodiment provides a centrifugal, airless dry fog dust suppression system for a port coal yard, applied to a coal transshipment base in a northern port with an annual throughput of 50 million tons. The coal yard area is approximately 80,000 m². 2It includes 2 stacker-reclaimers, 4 conveyor belt corridors and 6 material discharge ports.

[0112] A total of 60 centrifugal atomizing nozzles were installed in the coal yard, and their specific distribution is as follows:

[0113] The material discharge port area of ​​the conveyor belt: 6 nozzles are installed above and on both sides of each discharge port, for a total of 36 nozzles. Each nozzle is installed by a fixed bracket, the mounting base of which is fixed to the steel structure around the discharge port. The upright is 2 m high, and the nozzle mounting seat is set on the crossbeam. The spray direction is towards the dust generation point of the coal flow.

[0114] Stacker-reclaimer cantilever and bucket wheel: Each unit is equipped with 10 nozzles, for a total of 20 nozzles. Each nozzle is fixed to the lower surface of the stacker-reclaimer cantilever via a mounting bracket. The mounting bracket's fixing seat is welded to the lower surface of the cantilever. The connecting arm, 1.2 m long, extends outward from the cantilever. The nozzle mounting plate is fixed to the end of the connecting arm, and the nozzle is bolted to the nozzle mounting plate. The spray direction is the same as the coal flow direction and moves synchronously with the pitch and rotation of the stacker-reclaimer cantilever.

[0115] Around the coal stack: Four height-adjustable supports are installed around the perimeter of the storage area, with one nozzle installed on each support, for a total of four nozzles (the stack area is the main coal storage area, with a stack height of 8-15 m, and the nozzle support height is adjusted according to the stack height). The base of each height-adjustable support is fixed to the ground. The outer sleeve is 1.5 m high and 60 mm in inner diameter, and the inner sleeve has an outer diameter of 58 mm and a length of 8 m. Positioning / adjustment holes (12 mm in diameter and 150 mm in spacing) are provided on both the outer and inner sleeves. The supports are fixed to the desired height with locking pins. The nozzle mounting base is fixed to the top of the inner sleeve. The nozzle installation angle is adjusted to a 15° downward tilt angle with the horizontal plane, and the spray diffusion angle covers the top and side slopes of the stack.

[0116] Each centrifugal atomizing nozzle is configured with: an external rotor brushless DC motor with a rated speed of 8000 rpm; a 60 mm diameter centrifugal atomizing disc made of stainless steel with a wear-resistant and anti-scaling coating; and 48 radially distributed microgrooves on the upper surface of the centrifugal atomizing disc, each groove having a depth of 0.3 mm, a bottom width of 0.5 mm, a top opening width of 0.8 mm, and a trapezoidal cross-section. The droplet size distribution produced by the atomizing disc at 8000 rpm is: D50 = 18 μm, D90 = 28 μm.

[0117] The system employs a DN50 main water supply pipe laid along the main road of the coal yard, with each sprinkler head connected to the nearest branch pipe via a DN15 water supply pipe. The inlet pressure of the main water supply pipe is 0.2 MPa (provided by the municipal water supply network), eliminating the need for a booster pump station. A 200-mesh (approximately 75 μm) self-cleaning backwash filter is installed at the front end. The main power supply uses a 380V three-phase four-wire system, with each sprinkler head's power supply branch connected to a single-phase 220V line. The rated power of a single sprinkler head is 180 W.

[0118] The system does not include an air compressor station, air storage tank, or air supply pipeline.

[0119] Running result:

[0120] The system operates continuously for 24 hours. When the PM10 concentration in any area exceeds 150 μg / m³ 3 When the concentration drops to 120 μg / m³, the PLC controller automatically activates the corresponding zone nozzle group. 3 The system will automatically shut down at the following time. Operating data shows: PM10 average dust suppression efficiency: 91.2%; PM2.5 average dust suppression efficiency: 87.5%; total system power consumption (including all nozzles, PLC, and sensors): 11.8 kW; daily water consumption: approximately 8.5 m³. 3 (approximately 0.11 L / m) 2 •d); Changes in coal moisture content: The increase is <0.2%, which does not affect the calorific value of coal.

[0121] Example 2

[0122] The following optimizations were made based on Example 1:

[0123] Optimization 1: PLC-based zoned spray volume adjustment: The PLC controller, based on real-time feedback signals from dust concentration sensors, not only controls the start and stop of zoned nozzles but also adjusts the nozzle motor speed via a variable frequency speed control module, achieving stepless adjustment of the atomization volume. When the dust concentration is between 150 and 300 μg / m³... 3 At that time, the motor operated at 8000 rpm (full fog volume); 150~180 μg / m 3 The spray speed was reduced to 6000 rpm (medium mist level); at 120–150 μg / m³, it was reduced to 4000 rpm (low mist level maintenance). Actual measurements showed that this strategy, compared to constant speed operation, saved an additional 37% of water, reducing the overall daily water consumption to approximately 5.4 m³. 3 .

[0124] Optimization 2: Winter Freeze Protection: Self-regulating electric heating tape (25 W / m) is laid along the main water supply pipe and each branch pipe, and each sprinkler head housing has a built-in 30 W electric heating ring. The heating automatically starts when the temperature sensor detects an ambient temperature <2℃ and automatically stops when it exceeds 5℃. The system was tested continuously for 7 days at an ambient temperature of -18℃ in winter, and no pipe or sprinkler head icing failures occurred. The dust suppression efficiency was not significantly different from that under normal temperature conditions (PM10 dust suppression efficiency 89.8% vs 91.2%).

[0125] Comparison of optimization results (based on 5000 m) 2 (Based on coverage area)

[0126]

[0127] To verify the technical effect of the present invention, the following comparison was set up under the same coal yard conditions:

[0128] Comparative Example 1 (Traditional Sprinkler System):

[0129] High-pressure water jets are used for timed spraying, with droplet size >100 μm, and daily water consumption is approximately 120 m³. 3 The PM10 dust suppression efficiency is only 48%, and the coal moisture content increases by 2.5% to 3.0%, affecting the calorific value by about 150 to 200 kcal / kg.

[0130] Comparative Example 2 (Air-Water Two-Phase Flow Dry Fog Dust Suppression System):

[0131] Install one 37 kW screw air compressor + 3 m 3 Gas storage tank + DN40 gas supply pipeline, single set covers an area of ​​approximately 6000 m². 2 The PM10 dust suppression efficiency is approximately 93%. However, the total system power consumption is 52 kW (37 kW for the air compressor, 5 kW for the water pump, and 10 kW for other components), with a daily power consumption of approximately 1248 kWh. The gas supply pipeline is located in the open environment of the port, requiring at least four anti-corrosion maintenance and leak repairs annually.

[0132] Comparative Example 3: Ultrasonic dry fog dust suppression device:

[0133] The PM10 dust suppression efficiency is approximately 95%, demonstrating excellent performance. However, the purchase cost of a single unit is approximately 120,000 yuan, and the coverage radius is only about 8 meters (approximately 200 meters). 2 ), covering the same 80,000 m 2 The coal yard needs approximately 400 units, with an equipment investment of about 48 million yuan, far exceeding the budget of a typical port coal yard.

[0134] As can be seen from the above comparison, the present invention achieves a dust suppression efficiency close to that of the gas-water two-phase flow scheme (91.2% vs 93%), while the total power consumption of the system is only 17.7% of the latter (9.2 kW vs 52 kW), and it does not require an air supply system at all. The economic efficiency of equipment investment is significantly better than that of the ultrasonic scheme. The comprehensive technical and economic indicators have outstanding comparative advantages in the field of dry fog dust suppression in coal yards.

[0135] Table 2 Comparison of key indicators between the present invention and existing dust suppression technologies.

[0136]

[0137] The performance data for each comparative scheme in Table 2 are derived from the following sources: the relevant parameters of the traditional water spraying / fog cannon scheme and the air-water two-phase flow dry fog system are based on publicly known technical data and equipment sample data in the field; the data for the ultrasonic dry fog system are derived from the embodiment described in CN113318545A and the measured data of similar equipment; the data for this invention are derived from the measured operating data of Embodiment 1. All schemes were compared and tested under the same coal yard conditions (coal type, throughput, meteorological conditions) or calculated based on equivalent operating conditions.

[0138] As shown in the table above, this invention achieves PM10 dust suppression efficiency (88%–94%) comparable to that of a two-phase flow dry fog system (85%–95%) and an ultrasonic dry fog system (90%–96%), while maintaining a total system power of only 2–6 kW, which is 1 / 10 to 1 / 20 of that of a two-phase flow system. The cost per nozzle is only 1 / 100 to 1 / 1000 of that of an ultrasonic system, and it also has significant advantages in winter freeze protection. The comparative data demonstrate that this invention, while maintaining high dust suppression efficiency, achieves a fundamental simplification of the system architecture and a significant reduction in operating energy consumption, resulting in unexpected technical effects.

[0139] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these changes and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A centrifugal airless dry fog dust suppression system for use in a port coal yard, characterized in that, The system includes: a centrifugal atomizing nozzle array, a water supply pipeline, a power supply line, and a dust concentration monitoring and linkage control module. The centrifugal atomizing nozzle array consists of multiple centrifugal atomizing nozzles, and each centrifugal atomizing nozzle is dispersed in various dust-generating target areas of the port coal yard. The water supply pipeline is connected to each of the centrifugal atomizing nozzles and is used to supply atomizing water to each of the centrifugal atomizing nozzles; The power supply line is electrically connected to each of the centrifugal atomizing nozzles and is used to supply power to each of the centrifugal atomizing nozzles; The dust concentration monitoring and linkage control module includes multiple dust concentration sensors and a PLC controller. The multiple dust concentration sensors are respectively deployed in each dust target area, which includes the material discharge area of ​​the conveyor belt, the operation area of ​​the stacker-reclaimer, and the area surrounding the coal stack. The PLC controller is connected to each of the dust concentration sensors and each of the centrifugal atomizing nozzles, and is used to independently control the start, stop, and speed of each centrifugal atomizing nozzle in the corresponding area according to the detection signal of the dust concentration sensor in each dust target area. The system consists of a water supply pipeline and a power supply line, forming the working medium and power supply architecture. The system does not contain compressed air source equipment or air supply pipeline. The centrifugal atomizing nozzle includes a drive motor and a centrifugal atomizing disc. The drive motor drives the centrifugal atomizing disc to rotate, shearing and breaking the water into droplets. The atomization and breaking of the water is achieved solely by the mechanical centrifugal force generated by the rotation of the centrifugal atomizing disc.

2. The centrifugal dry fog dust suppression system for port coal yards according to claim 1, wherein the centrifugal atomizing nozzle further comprises: An impeller pump, coaxially mounted on the shaft of the drive motor, is used to pressurize low-pressure water from the water supply pipeline and deliver it to the central inlet of the centrifugal atomizing disc. The centrifugal atomizing disc is coaxially mounted on the upper end of the drive motor shaft, and the upper surface of the centrifugal atomizing disc is provided with microgrooves and / or tooth-like structures radiating outward from the center. A flow guide is placed above the centrifugal atomizing disc to control the spray diffusion angle.

3. The port coal yard centrifugal airless dry fog dust suppression system according to claim 2, characterized in that, The drive motor is an external rotor brushless DC motor with a rated speed range of 5000–12000 rpm and a protection level of not less than IP65; the centrifugal atomizing disc is made of stainless steel or titanium alloy with a diameter range of 40–80 mm and a wear-resistant and anti-scaling coating on its surface; the droplet size generated by the centrifugal atomizing disc under the drive motor is 10–30 μm; the spray diffusion angle controlled by the guide hood is 30°–90°, and the effective coverage radius is 3–8 m.

4. The port coal yard centrifugal airless dry fog dust suppression system according to claim 1, characterized in that, The water supply pipeline includes a main water supply pipe and multiple branch water supply pipes. Each centrifugal atomizing nozzle is connected to the main water supply pipe through its respective branch water supply pipe. The power supply line includes a main power supply line and multiple branch power supply lines. Each centrifugal atomizing nozzle is electrically connected to the main power supply line through its respective branch power supply line. The front end of the main water supply pipe is equipped with a precision filter with a filtration accuracy of not less than 50 μm.

5. The port coal yard centrifugal airless dry fog dust suppression system according to claim 1, characterized in that, The centrifugal atomizing nozzle array is arranged in zones as follows: Conveyor belt discharge port area: The centrifugal atomizing nozzles are installed above and on both sides of the discharge port through fixed brackets, with the spray direction facing the dust-generating area of ​​the coal flow discharge. 2 to 6 nozzles are arranged at each location. Stacker-reclaimer area: The centrifugal atomizing nozzles are fixed to the stacker-reclaimer cantilever or bucket wheel mechanism by a follow-up mounting bracket, and move with the stacker-reclaimer during operation. Each stacker-reclaimer is equipped with 4 to 12 nozzles. Coal stacking area: The centrifugal atomizing nozzles are arranged around the stack at intervals of 8 to 15 m via follow-up mounting brackets. The height of the lifting brackets is adjustable from 2 to 10 m, and the nozzle installation angle is adjustable.

6. The port coal yard centrifugal airless source-free dry fog dust suppression system according to claim 1, characterized in that, The dust concentration sensors are PM2.5 and PM10 dust concentration sensors, which are respectively deployed in each of the dust target areas. Each dust target area is equipped with a solenoid valve at the front end of the water supply branch pipe. The solenoid valve is connected to the PLC controller and is controlled by the PLC controller to achieve independent water supply to each zone. According to the detection signals of the dust concentration sensors in each zone, when the dust concentration in any zone exceeds a preset threshold, the PLC controller automatically turns on the centrifugal atomizing nozzle group corresponding to that zone and adjusts the speed of the drive motor according to the dust concentration level to change the atomization amount.

7. The centrifugal dry fog dust suppression system for port coal yards according to claim 1, characterized in that, The system also includes an anti-freeze heat tracing module, which comprises: a self-regulating heating cable laid along the water supply pipeline, an electric heating ring disposed on the centrifugal atomizing nozzle housing, and a temperature sensor; the temperature sensor, the self-regulating heating cable, and the electric heating ring are respectively connected to the PLC controller via signal connection. When the ambient temperature is below 2°C, the PLC controller automatically starts the heat tracing, and when the ambient temperature is above 5°C, the heat tracing automatically stops; the system also includes a drain valve, which is connected to the PLC controller via signal connection, for draining the water accumulated in the pipeline and nozzle when the system is not in use for a long period of time.

8. The centrifugal dry fog dust suppression system for port coal yards according to claim 1, characterized in that, The water supply pipeline is also connected in parallel to a dust suppressant mixing and injection device, which is used to inject wetting agent or crusting dust suppressant into the atomized water at a volume ratio of 0.1% to 1.0%.

9. A dust suppression method for a centrifugal, airless dry fog dust suppression system for port coal yards as described in any one of claims 1 to 8, characterized in that, Includes the following steps: The concentrations of PM2.5 and PM10 in the air are detected in real time by dust concentration sensors deployed in various dust-prone areas; The PLC controller receives the detection signals from each of the dust concentration sensors and compares the detection values ​​with preset thresholds. When the dust concentration in any area exceeds the preset threshold, the PLC controller controls the solenoid valve corresponding to that area to open, and at the same time starts the centrifugal atomizing nozzle group corresponding to that area. The centrifugal atomizing disc is driven by the drive motor to rotate and shear and break the water into droplets for dust suppression spraying. The PLC controller adjusts the speed of the drive motor according to the dust concentration level to adjust the atomization amount. The higher the dust concentration, the higher the motor speed is controlled to increase the atomization amount. When the dust concentration drops below the safety threshold, the PLC controller controls the solenoid valve to close and stop the centrifugal atomizing nozzle group in that area; The preset threshold is PM10 concentration ≥ 150 μg / m 3 The safety threshold is PM10 concentration ≤ 120 μg / m 3 .

10. The dust suppression method according to claim 9, characterized in that, It also includes antifreeze control steps: the temperature sensor detects the ambient temperature in real time and feeds it back to the PLC controller. When the ambient temperature is below 2°C, the PLC controller automatically starts the self-regulating electric heating cable and the electric heating ring of the nozzle housing laid along the water supply pipeline for heating. When the ambient temperature is above 5°C, the heating is automatically stopped. When the system is not in use, the PLC controller controls the drain valve to open and drain the water accumulated in the pipeline and nozzle.

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