| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an aeration device which can prevent sewage from flowing backward from an aeration tank even during the stop of aeration. <P>SOLUTION: The aeration device 10 has an aeration means comprising elastic porous bodies 21, and an air chamber 30. A ball valve 40 is movably disposed inside of the air chamber 30. The ball valve 40 opens a first air supply port 15 during air supply from an air supply pipe, and moves so as to occlude the first air supply port 15 during the stop of air supply. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
