A combined ultrasound - - return air flushing process for the chemical-free in - situ - cleaning dip-coated membranes during the operation in backwashing

摘要

Processes for the purification of a liquid filter system, the at least one in the fluid to be filtered (4) shown, back flow diaphragm stack (2) and at least a cavitation generates ends ultrasonic transducer (1) in an open and therefore is not pressurized filtration tank (3), characterized by the following, successive process steps,a) coupling of cavitation of which decreases with increasing production of ultrasound in the fluid to be filtered (4) parallel to the membrane surfaces of the in the liquid remaining diaphragm assembly (2) with simultaneous backwashing with permeate and subsequentb) by means of flow of the filtration gas bubbles have strength membrane surfaces without the coupling of cavitation of which decreases with increasing production of ultrasound, however, in the case of simultaneous backwashing with permeate of the in the fluid to be filtered (4) remaining membranes of the diaphragm assembly (2).