Dynamic filtration device, for microfiltration, ultrafiltration, nanofiltration or inverse osmosis, has rotating disc between two consecutive filters in vessel using membranes

摘要

The filtration device is modular, and two consecutive support-trays (4, 5) are separated by a spacer (11) to facilitate their installation and removal, modify the number of compartments, ensure the vessel is leak-proof and allow the gap between disc and membrane to be modified. The membranes are for microfiltration, ultrafiltration, nanofiltration or inverse osmosis. A cylindrical vessel (E) has a base (1), a collar (2) and a cover (3) with an upper face (31) and a side wall (32) which seats in the collar. At least two filters F1 and F2 divide the vessel into at least three compartments. Each filter comprises a support-tray (4, 5) fixed to the vessel and two membranes on either side of the support-tray. A rotating disc (6) is placed between two consecutive filters. A common inlet device (7) for the liquid to be filtered passes through the base or the cover and a common outlet device (8) for the residue retained by the filters passes through the cover or the base. At least two outlets for the filtrate pass through the collar and an axle (10) along the axis of the vessel carries the disc(s) and can be rotated. Each support-tray and the membranes on each side of it are disc-shaped. The filter is an assembly comprising a support-tray with a membrane on each side and a draining layer between the face of the support-tray and the membrane. The drain is not woven. The support-tray has radial striations to evacuate the permeate. The filter is a single piece of porous material, fritted or otherwise, with the porosity increasing towards the middle so the membranes are formed by the faces of the piece with lowest porosity, the support-tray is the central part with raised porosity and the draining layer is the intermediate parts of medium porosity between the faces and the center. The filter is ceramic. Alternatively, the filter is an assembly of a support-tray with two pipes of diameter d2 to evacuate the permeate sideways and two organic or mineral membranes on either side of the support-tray. The pipes are radial and are connected to conduits of diameter d3 less than d2 formed in each side of the support-tray. The disc has fins.