| 摘要 |
PURPOSE:To eliminate the concn. polarization along the surface of a membrane by agitating the flow in a raw water flow passage and to obtain a large quantity of transmitted water without increasing the flow speed of raw water, by using a corrugated board-shaped spacer having a large number of openings piercing in the thickness direction thereof. CONSTITUTION:A corrugated board-shaped spacer 2 having a large number of openings 2 piercing in the thickness direction thereof provided to the non-top parts of corrugations by drilling is used and a bag-shaped separation membrane 3 is wound around the outer periphery of a water collecting pipe 1 through the spacer 2 to form a spiral shape membrane module. By this method, raw waters on both surface sides of the spacer 2 are mixed through the openings 2a and the flow along the surface of the spacer 2 is agitated because of the presence of the openings 2a to eliminate concn. polarization and a large quantity of transmitted water is obtained. Further, unlike a net like spacer, the clogging of a raw water passage due to the suspended substance contained in the raw water is also prevented.
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