Patent ID: 7160454

Claim:
A head piece for a membrane filter to treat untreated water contained in a basin at an ambient pressure comprising: a) a permeate collecting chamber sealed from the untreated water and in fluid communication with a vertical bundle of capillary membranes where each capillary membrane has a first lower end open to the permeate collecting chamber and a sealed, freely movable second upper end opposite the first open end, wherein a pressure reduction on the permeate collecting chamber to less than the untreated water pressure provides a driving force for membrane filtration of the untreated water; b) an air duct contained in the head piece and connected to a mouth piece positioned within and surrounded by the capillary membranes, the mouth piece having at least one outlet for air to provide bubbles that flow through the bundle of capillary membranes from the inside to the outside of the bundle of membranes and partially flow away in the lengthwise direction, contact the capillary membranes over the length of the membranes to remove fouling materials from the membranes independent of the flow velocity of the untreated water and cause the membranes to sway; and c) a basket connected to the head piece to limit lateral sway of the capillary membranes.