Etude hydrodynamique d'un module de filtration dynamique

A dynamic filtration technique, called Rotating and Vibrating Filtration (RVF) and designed to treat biological suspensions, has been investigated under hydrodynamic consideration. The moduleis divided into parallel cells including flat disc membranes fixed onto a porous substrate which drained the permeate, and impeller-shaped rotating bodies attached to a central shaft. Theorical analysis and literature survey highlight that the local shear rate could not be easily estimated in the RVF module. The investigation of hydrodynamic behaviour is required to understand and model local phenomena, but the whole difficulty rests in the complex hydrodynamics of the RVF system. In this paper, the friction and the power consumption curves in the RVF module were reported. A semiempirical correlation has been established to integrate the impact of the rotating speed on Darcy's number. The additional pressure in the filtration room is reported and is given by Bernoulli's equation. It affords the core velocity coefficient between the impeller and the membranes. Of course the knowledge of transmembrane pressure is fundamental, but the estimation of the shear rate at membrane surface could also be very useful in predicting and reducing fouling.Etude hydrodynamique d'un module de filtration dynamiqu