Process fundamentals of membrane emulsification: Simulation with CFD

Membrane emulsification is a process in which a to-be-dispersed phase is pr essed through a membrane; the droplets formed are carried away with the con tinuous phase. To design a suitable membrane setup, more insight into the f ormation of the droplets at tile membrane surface is needed. Therefore, the formation of one droplet from a cylindrical pore was calculated using comp utational fluid dynamics. From the resulting droplet diameter (33 mum; pore diameter; 5 mum) and the calculated droplet shape, the maximum membrane po rosity was calculated to be 1.5%, to prevent coalescence of droplets gi owi ng on neighboring pores. Due to the deformation of the droplet and the form ation of the neck, the pressure drop over the pore and the velocity of oil in the pore varied in time. During necking, the velocity in the pore den-ea sed sharply. After detachment of the first droplet, no satellite droplets w ere formed, but a small oil volume remained attached at the pore, forming a new droplet.