The Simulation of the Drop Sizes in Turbulent Liquid-Liquid Dispersions

On the basis of considering the effects of dispersion phase viscosity on the breakage frequency of the droplets,the effects of dispersion phase viscosity on the coalescence frequency of the droplets were further investigated. The dispersion phase viscosity was also taken into account when modeling the drainage time,and a new droplet coalescence frequency equation was achieved. By solving the population balance equation,the Sauter mean diameters of turbulent liquid-liquid dispersion system in a stirred tank were obtained. It was found that the Sauter mean diameters predicted by the proposed regulated model are in a better agreement with the experiment data than those predicted by Coulaloglou and Tavlarides’ models. The calculation results indicate that the dispersion phase viscosity possesses double effects on the Sauter mean diameters of the droplets. On the one hand,the dispersion phase viscosity resists the breakage of the droplets,which leads to enlarge the droplet diameter; on the other hand,it also resists the coalescence of the droplet at the same time,which leads to decrease the droplet diameter.