Causes and countermeasures for dust dispersion in the coal conveyor belt corridor

Thread Content

The coal discharge point is the area where dust accumulation in the coal conveyor belt corridor is most common； Reason/mechanism: During the discharge process, dry coking coal (especially that containing fine coal dust) gains significant kinetic energy due to collisions with the belt and the effect of gravity. At the moment the coal flow settles on the belt, the smaller coal particles or dust are subjected to strong forces, causing them to be ejected into the air ； Common coal falling points: feed inlet ； discharge port ； Chute ； Other factors: particle size of the coal being transported ； Moisture content of the coal being transported ； Conveying speed ； Conveyor inclination angle ； When the particle size of the coal powder is relatively fine, the moisture content is very low, the conveying speed is high, and the inclination angle is large, it is possible for the coal powder to fly upward above the belt ； Main dust suppression measure: Steam humidification ； Closed design for coal discharge point, operating under negative pressure ； Spray humidification (dry fog dust suppression system) ； Steam humidification: low investment, quick results, simple installation and operation ； However, the temperature in the belt corridor rises in summer ； Closed design for the coal discharge point, operating under negative pressure: https://pic1.zhimg.com/80/v2-332869e74fe93efbdb26acef41df6de4_1440w.jpg The image on the right shows the head end of the conveyor; the vertical arrow indicates the direction in which the coarse coal is discharged from the dryer to the conveyor ； https://pic2.zhimg.com/80/v2-ee9535f633221df0088db85b99c0c005_1440w.jpg The image on the right shows the part where the coal powder collected by the dust collector is fed into the conveyor ； Horizontal arrow: Conveying direction of the conveyor ； Vertical downward arrow: Direction of transport of the coal powder collected by the dust collector ； Vertical upward arrow: Direction of dust-containing gas flow ； https://pic2.zhimg.com/80/v2-03fd886c8a53f8d504685e9b330eadd9_1440w.jpg https://pic3.zhimg.com/80/v2-293f058d6fb5b92d7e0a2a0605ed3012_1440w.jpg The coal powder chute collected by the dust collector (under negative pressure) https://pic1.zhimg.com/da8e974dc_s.jpg?source=12a79843 Video of the coal dryer; belt corridor (no dust problem) https://pic1.zhimg.com/da8e974dc_s.jpg?source=12a79843 Video of the coal dryer · 1 play Successful case: All 6 coking coal drying plants of Arch Coal adopted this measure, with no dust problems during operation ； Moisture content at the drying outlet: 5–6%; moisture content at the dust collector outlet: 2–3%. The coarse coal discharged from the dryer is fed onto the conveyor belt before the coal powder collected by the dust collector ； Spray humidification (dry fog dust suppression system) ； Dry fog dust suppression for coal loading and unloading systems in ports https://pic2.zhimg.com/da8e974dc_s.jpg?source=12a79843 Video of successful applications: Dry fog dust suppression for coal loading and unloading systems in ports ； Spray humidification (dry fog dust suppression system) ； Dry fog dust suppression in coal belt conveyor systems ； https://pic4.zhimg.com/da8e974dc_s.jpg?source=12a79843 Video of the coal dryer · 2 views Success case: Dry fog dust suppression in a coal belt conveyor system ； Spray humidification (dry fog dust suppression system) ； Dry fog dust suppression in coal belt conveyor systems https://pic4.zhimg.com/da8e974dc_s.jpg?source=12a79843. Video on coal dryers: Wetting effect of the dry fog dust suppression system. Taking a coal processing plant with an annual production capacity of 15 million tons as an example, when conventional spray dust removal methods are used, the total dust concentration at the end of the conveyor belt ranges from 23 to 160 mg/m3, while the concentration of respirable dust is between 2 and 28 mg/m3. The daily water consumption for dust removal at the end of the conveyor belt is 95 tons ； After adopting the pneumatic mist dust removal system, the total dust concentration in the working area was between 1.5 and 3.6 mg/m3, while the concentration of respirable dust was between 0.2 and 1.3 mg/m3; the daily water consumption was only 4.5 tons ；