MEMBRANE CARTRIDGE AND ITS OPERATION

摘要

PROBLEM TO BE SOLVED: To reduce the fatigue of a filtration membrane in a rectangular plate like membrane cartridge vertically dipped and mounted in a liquid to be treated. SOLUTION: The filtration membrane 3 covering both front and back surfaces of a filter plate 2 is fixed to the filter plate 2 on the membrane peripheral part, a filtrate flow passage 4 communicated with the permeation side of the filtration membrane 3 is provided on the filter plate 2 and a filtrate take-out nozzles 5 having one end communicated with the filtrate flow passage 4 and another end opened outside of the filtration membrane 3 is provided at each peripheral part of the filter plate 2 arranged along the width direction of a membrane case 25. One of the filtrate take-out nozzle 5 at the filter plate peripheral part is opened and the other filtrate take-out nozzles 5 are closed by freely detachable nozzle closing caps 8. By the constitution, the mounting direction of the membrane cartridge 1 is changed by changing the opened filtrate take-out nozzle 5 and the fatigue of the membrane fixing part 9 due to aerating air or ascending water flow is reduced.