Effect of concentration and sizes of solid particles in slurry droplets on their collision behavior in gas

Abstract

Experimental research findings are reported on the effect of concentrations and sizes of particles, as well as the sizes of initial droplets containing these particles, on the characteristics of their collisions in gas. Droplets of liquid containing bituminous coal particles with a size of 60–120 μm and MS-VP-A9 glass microspheres with a size of 20–120 μm were utilized. The particle concentration ranged from 0.01% to 1%. The patterns of collisions of low-concentration slurry droplets have been recorded. Four collision regimes of droplets have been distinguished: bounce, coalescence, separation and disruption. The characteristics of secondary liquid fragments (child droplets) have been determined. Conditions of coalescence, bounce, separation and disruption of slurry droplets, as well as their secondary atomization for subsequent intensification of physicochemical processes have been defined. Guidelines have been provided for using the research findings in industrial applications with variable Weber numbers and impact angles.