Operating characteristics of acoustically driven filtration processes for particulate suspensions

Operating characteristics for an ultrasonically assisted filtration techniq ue applicable to micron to millimeter-sized particles suspended in liquid h ave been studied. The technique uses a highly porous filtration medium havi ng pores up to two orders of magnitude larger than the particles being coll ected. When a resonant ultrasonic standing wave field is applied to the med ium, the particles become trapped on the elements comprising the porous med ium or within its pores. The test suspension consisted of 325-mesh polystyr ene particles in water. The porous medium was a polyester mesh containing 3 0 pores per inch (the nominal pore size is 847 mu m). Filtration efficienci es ranging from 60 to 85% have been observed. The effect of flow configurat ion on filtration efficiency and two approaches for cleaning of the mesh ha ve been examined.