FILTER

摘要

A filter element (2) comprising a membrane filtration cell (4) internally arranged with a filtration membrane, a water collection cell (5) arranged adjacently to the membrane filtration cell (4) and becoming a channel of filtrate filtered by the filtration membrane, an outer circumferential wall surrounding these cells, and a water collection slit (7) cut in a predetermined direction to communicate from one portion of the outer circumferential wall to the other portion thereof while penetrating the water collection cell (5) is incorporated in a casing (12) to constitute a filter. The casing (12) is provided with a liquid supply port (17) for backwashing, wherein the angle ? between the cutting direction of the water collection slit (7) and the axial direction of the liquid supply port (17) for backwashing is 90°±25°. According to the inventive filter, liquid for backwashing supplied into the casing can be prevented from touching the peripheral part of the water collection slit directly while sustaining high pressure when backwashing of the filter element is performed and the liquid for backwashing can be spread uniformly over the entire filter element.