Exploratory investigation on the suppression efficiency of fugitive dust emitted from coal stockpile: Comparison of innovative atomizing and traditional spraying technologies

Abstract

This research applied two suppression technologies of atomizing dust suppression (ADS) and spraying dust suppression (SDS) to eliminate fugitive dust emitted from coal stockpiles and further investigated their optimal operating parameters. In field tests, the mass concentrations of TSP, PM10, and PM2.5 were simultaneously measured at both upwind and downwind sites of a simulated coal stockpile to determine the suppression efficiency of fugitive dust. High concentrations of fugitive dust were observed under a strong wind speed of 10 m/s, particularly for particle sizes larger than 7 μm. Overall, the suppression efficiencies of fugitive dust by ADS (75.50–88.17 %) were always higher than those by SDS (70.70–84.50 %). Fine mist atomized by ADS covered a wider surface area of the coal stockpiles and captured more dust in the air than SDS. The suppression efficiencies of fugitive dust for intermittent watering (82.81 %) were higher than those for continuous watering (77.75 %). Intermittent watering could maintain a protective moisture layer over the entire surface of coal stockpiles, thus extending the drying time of moisture from the coal stockpiles. The optimal operating parameter for ADS was intermittent atomizing at an angle of 30°, while that for SDS was intermittent spraying at an angle of 45°.