122 / 2023-06-21 05:54:22

Dynamic wetting characteristics and regulation of dust suppression droplets impacting the bituminous coal surface

coal surface,dynamic wetting,droplet impact,dust control,spreading coefficient

Aiming at the issues of the dynamic wetting characteristics between droplets and coal is not clear. This research combines the visualization experiments of droplets impacting on bituminous coal surface and the molecular dynamics (MD) simulation to study the dynamic wetting characteristics of anionic and nonionic surface-active droplets impacting on bituminous coal surface and the regulation behaviors of water-soluble polymer sodium carboxymethyl cellulose (CMC-Na) on the dynamic wetting characteristics of nonionic surface-active droplets impacting on bituminous coal surface. In the research process, the dimensionless spreading coefficient is used to evaluate the dynamic wetting process of droplets impacting on bituminous coal surface. The visualization experiment of surface-active droplets impacting on bituminous coal surface shows that the addition of anionic and nonionic surfactants can effectively promote the wetting behavior of pure water droplets. With the increase of impact velocity and solution concentration, the dimensionless spreading coefficient of droplets increases. Moderately increasing the impact velocity and solution concentration is beneficial to promote the spreading behavior of droplets. The molecular structures of surfactants can affect the droplet spreading behavior significantly. The addition of CMC-Na can obviously reduce the contact angle of the mixed dust suppression solution and increased the viscosity, but basically cannot change the surface tension of the solution. When the concentration of CMC-Na is 0.1 %, the dimensionless spreading coefficient of the droplet is the largest, indicating that the addition of a small amount of CMC-Na will further promote the wetting behavior of nonionic surfactant droplets. In the process of droplets and coal dynamic wetting, the dimensionless maximum spreading coefficient and the dimensionless steady-state spreading coefficient can be used to better evaluate the droplet dynamic wetting characteristics. MD simulation results verify the effectiveness of the visualization experiment. The research results are of great significance to the research, development, and scientific utilization of water-soluble dust suppressants.