| 摘要 |
<p>PROBLEM TO BE SOLVED: To simply and easily prevent clogging in an aeration pipe and retain the aeration pipe in good state for a long duration. SOLUTION: This aeration apparatus comprises an aeration pipe 4 installed under membrane units 10 and having a plurality of aeration holes facing downward and check valves 15 made of rubber and installed in the aeration holes of the aeration pipe. Each of the check valves made of rubber comprises a dome part produced by cutting a hollow spherical body into halves, a flange part extended outward from the rim part of the dome, and a hollow aeration hole insertion part uprightly formed from the inner circumferential side of the flange part. Moreover, a slit which is opened at the time when aeration is carried out and closed at the time when aeration is not carried out is formed in each semi-spherical face of the dome part of each check valve 15 made of rubber and an engaging claw part is formed in the outer circumference of the terminal part of the aeration hole insertion part.</p> |
