Investigation of O/W emulsion separation and redispersion using fibrous PTFE bed coalescer

A series of fiber beds consisted of woven PTFE fiber mesh were used to investigate the influence of bed porosity (gradient porosity), permeability, specific surface area of bed, and superficial velocity on coalescence and separation process. It is found that too small bed porosity will not give better separation performance, for the reason of redispersion. The separation efficiency does not depend on the pore size but on the surface area of bed when the porosity is above 0.850. And a rapid drop of separation efficiency takes place above the porosity of 0.903. For effective separation of liquid droplets from a fluid stream, the gradient increasing porosity is the most favorable structure, which is effective to avoid redispersion of coalesced droplets.