Evolution of dispersed drops during the mixing of mineral oil and water phases in a stirringtank

In this paper, a focused beam reflectance method is used to investigate the evolution of dispersed droplets at various dispersed volume fractions for an Exxsol D80 mineral oil–water dispersion in a stirring tank. Two types of inversion experiments are compared, the direct and continuous mixing of the oil–water phases. The number density of the chord lengths and distributions are identified as the main parameters for comparison. The drop coalescence is dominant slightly before inversion, at which point the measured mean square weighted (Sqr-wt) chord length increases significantly. The way of mixing will also influence the effect of drop coalescence and result in different inversion processes.

► Focused beam reflectance method is introduced to investigate the dispersed droplets.
► Both direct and continuous mixing of oil and water phases are compared.
► The drop coalescence is dominant slightly before inversion.
► The way of mixing is found to influence the effect of drops coalescence