MEMBRANE SEPARATION TREATING DEVICE

PURPOSE:To prevent the deposition of a gel layer on the surface of a membrane, to miniaturize the title device, and to reduce the cost of the device by connecting the liq. concentrate outlet of the membrane separation unit wherein a membrane surface cleaning body is inserted in an internal pressure-type tubular membrane to the suction port of a reciprocating pump, and connecting a check valve to the inlet for a raw liq. to be treated. CONSTITUTION:The compressed air from a compressor 40 is alternately supplied to air chambers 26 on both sides through an air supply pipe 41 and a supply and discharge unit 31 to operate the reciprocating pump 6, and the raw liq. 36 to be treated in a raw liq. tank 37 is sucked into the internal pressure-type tubular membrane 1 and a pump room 27 from a check valve 8. The inside of the membrane 1 and pump room 27 are depressurized, and the membrane surface cleaning body 2 is pressed by the flow of the raw liq. 36, goes up while cleaning the membrane surface, collides against an upper partition plate 11, and stops. When the pump 6 begins to discharge, the check valve 8 is closed, the insides of the pump room 27 and membrane 1 are pressurized, the raw liq. permeates the membrane 1 from the inside to the outside, the membrane surface cleaning body 2 is pressed down by the back flow of the raw liq., and the membrane surface is again cleaned. The liq. concentrate not permeating the membrane is returned to the raw liq. tank 37 from a discharge port 22.