| 摘要 |
PURPOSE:To prevent the oxidation of the cation and hyperfine particles in a filtrate and to efficiently clean off the deposit on the inner or outer surface of a hollow yarn membrane by forcing in a nonoxidizing gas along with filtered water or washing water at the time of cleaning the hollow yarn membrane filter under pressure. CONSTITUTION:When the hollow yarn membrane filter 1 is cleaned, valves 14 and 15 are opened, compressed gaseous nitrogen, etc., are introduced into the upper part 20 of the filter 1 from a nonoxidizing gas holder 16. The filtered water existing in the upper part 20 is permeated by the pressure through a hollow yarn membrane 2 from the inside to the outside. The permeated liq. is further passed through an overflow pipeline 18, and collected in an overflow tank 19. Since the nonoxidizing gas is utilized in cleaning, the cation and hyperfine particles contained in the filtrate are not oxidized nor deposited, hence the inner surface of the membrane is not contaminated.
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