ROTARY DISC FILTRATION DEVICE

A rotary disc filtration device (30 in fig. 12) having a fluid filtration gap (56 in fig. 14) between a filtration surface (62) and a disc (36) is disclosed. The disc (36) and/or filter (34) has one or more spiral grooves (52) in fluid communication with fluid in the gap (56). The disc (36) and/or filter (34) is rotated and one or both may be axially oscillated and/or vibrated to create the shear at the filter surface (62) that increases permeate flux through the filter (34). Several discs (36 in fig. 24) and filters (34) may be interleaved to increase filtration device capacity and make more efficient use of equipment space. In such a device (106), the discs (36) can be mounted on a common shaft (104 in fig. 25) for rotation in unison and can have spiral grooves (52) on both major faces (132, 134) of each disc (36). The filters (34) are held stationary in that device (106) and are fluidly connected to facilitate collection of the permeate.