| 摘要 |
PROBLEM TO BE SOLVED: To provide an upward flow filtration apparatus and filtration method by which pressure difference increased between planed back washing processes is decreased without carrying out the back washing. SOLUTION: In the upward flow filter apparatus 10 having a filter layer 12 in which filter media are filled in a filter column 11 and through which raw water is passed upward to be filtered, a pressure difference measuring means 18 for measuring the pressure difference of the filter layer 12, a rotary blade 13 provided in the lower part of the filter column 11 and rotatably driving means 14, 15 rotating the rotary blade 13 at a controlled number of the rotation for a prescribed time to fluidize only a surface part of the filter layer 12 in the in-flow part or the whole filter layer 12 are installed and the surface layer back washing for fluidizing only the surface layer 12a is carried out between the whole back washing carried out by fluidizing the whole filter layer 12. COPYRIGHT: (C)2003,JPO
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