| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a structure for effective removal of an adhered or deposited contaminant in a vent tube with lower workload and cost. <P>SOLUTION: A first opening hole and a second opening hole are formed in a channel of a downward flow section that constitutes an inlet of a vent tube. Once a year, compressed air is supplied via first and second air tubes for approximately 3 to 8 minutes. The compressed air supplied from the first and the second air tubes whirls and agitates sewage both in axial and circumferential directions. The whirled and agitated flow serves to effectively pulverize a sedimentation layer of suspended contaminants deposited around the water level of the downward flow section so as to be forcibly flown away. <P>COPYRIGHT: (C)2012,JPO&INPIT |
