■Spray dust suppressionThe mechanism involves water with a certain pressure, which is uniformly sprayed into the air above the coal storage yard within a certain angle range through the automatic rotation nozzle of the spray gun. After the water droplets fall, they wet the surface of the coal pile, causing the fine particles of coal powder to bond together through the tension of water molecules, and also increasing the weight of the fine particles of coal powder itself, avoiding dust blowing by the wind. It also has the function of humidification and prolonging the spontaneous combustion period of coal. The sprinkler system generally consists of spray guns, solenoid valves, water supply pumps, pipelines, valves, power distribution, and control. In the north, in order to prevent accidents such as freezing pipelines and spray guns in winter, an automatic drain valve is installed behind each spray gun solenoid valve to drain the water stored in the spray gun riser. The selection and arrangement of spray guns are crucial, and their parameters mainly include range, flow rate, elevation angle, rotation angle, etc. In theory, the length of the coal yard determines the number of spray guns, the width of the coal yard determines the range of the spray guns, and the height of the coal pile determines the elevation angle of the spray guns. According to the coal mining method, water supply pipeline layout, and surrounding environment in the coal yard, the arrangement of spray guns can be divided into two methods: single-sided and double-sided. The main indicator is to ensure that the spray coverage rate reaches over 98%, and strive to minimize the number of spray guns, water supply pipelines, cables, etc. to reduce project investment. The operation control of the sprinkler system can be divided into two modes: PLC program control and manual control. Program control mainly refers to the automatic operation of the spray gun in various forms such as simultaneous spraying, cyclic spraying, and timed spraying according to the set program based on the coal storage amount and spraying time in the coal storage yard. At the same time, the operating program can be adjusted at any time according to special circumstances, and the spraying time can be increased or decreased. Manual control refers to manually controlling the operation of each spray gun by operating the on/off button of a certain spray gun solenoid valve in the control box as needed. The coal storage yard is a large open-air open material accumulation site with a relatively open area, and there is often dust generated by the operation of large equipment such as bucket wheel machines and bulldozers. The extremely fine particles of coal powder on the surface of the coal pile are easily lifted by the wind, even forming a "coal dust dragon" that flies for several kilometers. Not only does it greatly waste valuable coal resources and cause economic losses, but it also greatly pollutes the surrounding environment