| 摘要 |
<p>A method of producing purified water economically and safely by using a hollow fiber type ultrafiltration membrane formed in a filtration layer by regularly and overlappingly winding, to open uniformly, hollow yarn bundles around a core disposed at the center part of a vertical cylindrical type pressure vessel so that the core extends in the axial direction of the pressure vessel, characterized in that a filtration operation is of a full amount filtration and performed by supplying raw water from an outer peripheral space formed between the inner peripheral surface of the pressure container and the outer peripheral surface of the filtration layer to the core and draining filtrated water from the inside hollow of the hollow yarns, and the cleaning operation of the filtration layer including the membrane surface of the hollow yarns is performed by a basic cleaning comprising a back pressure cleaning in which the filtrated water flows from the inner hollow of the hollow yarns to the outside thereof and a reverse flow cleaning by the raw water (filtrated water may be used; applicable hereafter) supplied from the core to the outer peripheral space.</p> |
