Numerical Study of Droplets Coalescence in an Oil-Water Separator

Through this paper a numerical modeling of oil-water flow through parallel plates integrated into a rectangular oil-water separator is conducted. Oil droplets of tiny sizes are dispersed in water and rectangular plates are used as coalescing chambers. Results have shown that upgrading a conventional API skimmer by introducing parallel coalescing chambers enhances coalescence of oil droplets by increasing their sizes. Since the buoyancy force that enables oil to float on water surface is proportional to the volume of the submerged oil droplet, droplets of greater sizes are then susceptible to rise to the water surface. Droplets floating on the water surface can be then easily skimmed. COMSOL Multiphysics modeling of two phase flow between two plates of the coalescing chamber has enabled to visualize the coalescence phenomenon and to determine coalesced droplets diameters. Further, the capability of enhancing oil water separation through coalescing chambers was discussed for the studied case.