Patent ID: 6224766
Filing Date: 2001-05-01
Classification: B01D,C02F

Abstract:
A membrane treatment method, comprising the steps of:(a) supplying raw liquid from a raw liquid tank to a circulation tank;(b) supplying raw liquid and circulation liquid from the circulation tank into an inter-membrane passage formed within the interior of a membrane apparatus divided into a plurality of partition plates forming blocks, wherein each block includes a plurality of filtration membranes, wherein the membrane apparatus is disposed separately from the circulation tank;(c) flowing the raw liquid and circulation liquid within the inter-membrane passage upward in alternative blocks and downward in the remaining blocks;(d) extracting filtrate from the raw liquid within the inter-membrane passages via the filtration membranes, while returning the remaining raw liquid and circulation liquid to the circulation tank;(e) circulating the circulation liquid by a circulation pump, which causes liquid circulation within the inter-membrane passages, and is not designed for applying pressure for extracting filtrate, disposed between the circulation tank and the membrane apparatus; and(f) overflowing a portion of the circulation liquid from the circulation tank to the raw liquid tank.