| 摘要 |
PROBLEM TO BE SOLVED: To discharge air in a water collection pipe quickly without retaining air in the pipe and to apply a negative pressure uniformly to all membrane modules. SOLUTION: In a membrane filter 12, membrane modules 13 immersed in a reaction tank 11 are connected with a water collection pipe 15 arranged vertically, a suction system 16 having a suction pump 18 is connected to the upper end of the pipe 15, a descending channel part 19a is formed in the system 16, and a prescribed negative driving pressure is applied to the modules 13. The bore diameter of the channel part 19a is set up so that a flow velocity in the channel part 19a is 0.7-1.2 m/sec.
|
