AIR BUBBLE SUPPLYING DEVICE FOR IMMERSION TYPE MEMBRANE FILTRATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To realize an air bubble supplying device exhibiting compactness and profitability which are characteristic of a tubular filtration membrane module for an immersion type membrane filtration system. SOLUTION: This air bubble supplying device 4 is provided with an air bubble generating unit 41 for supplying air bubbles to the tubular filtration membrane module which has many pieces of tubular filtration membranes housed and held in the housing container and a guiding cylinder 40 above which the tubular filtration membrane module can be disposed and which is used for guiding the air bubbles from the unit 41 toward the tubular filtration membrane module. The cross sectional shape perpendicular to the axial direction of the cylinder 40 is made substantially similar to that perpendicular to the axial direction of the tubular filtration membrane module. The unit 41 has a plurality of air bubble spouting holes 44 in such a positional pattern that the air bubbles of at least 30% of the mean value of air flow rates per one piece of the tubular filtration membranes, which is obtained by dividing the total flow rate of the air bubbles supplied from the unit 41 by the total pieces of the tubular filtration membranes, can be distributed to at least half of the tubular filtration membranes.