Dynamic wetting characteristics of two droplets impacting a spherical dust particle

Abstract

The removal of dust based on water misting is one of the most effective measures for dust control, and the basis of this method lies in the liquid–solid impact behavior. To further improve the dust removal efficiency, in this work, the removal mechanism was studied at the microscopic level, and the dynamic impact between two water droplets and a spherical dust particle was simulated using the coupled level-set/volume-of-fluid (CLSVOF) method. The optimal parameter ranges for micron-level dust removal were determined through the method of variable control, and the reliability of the obtained results was experimentally verified. When two droplets continuously or simultaneously impact a spherical particle, the liquid film formed undergoes deformation phenomena such as fusion, rupture, stretching, contraction, and fragmentation. The liquid film is more likely to break at higher droplet velocities, leading to the filling of the gas film and hindering the wetting process. The optimum contact angle and velocity range of the liquid droplets to completely encapsulate the dust particles were found to be θ = 2 and V = 10–20m/s, respectively. The experimental results also showed that for the same dust particle size, the dust removal efficiency initially increased but then decreased with increasing dust concentration. The optimum dust removal efficiency of 98.1% was achieved for θ = 2 and V = 10m/s. This study sheds new light on the dust removal mechanism of water mist-based dust removal technologies and can aid in the design and parameter optimization of more effective dust suppression systems.