| 摘要 |
PROBLEM TO BE SOLVED: To provide a device in which the clogging of a filled layer is prevented, and to provide a filtering treating method using the device in a pressure type upward stream filter having the filled layer consisting of filter material particles inside. SOLUTION: In the pressure type upward stream filter having the filled layer 3 consisting of the filter material particles inside and in which a raw water to be filtered is passed upward from below the filled layer 3, (1) the filled layer 3 is formed on the bottom surface of a vessel, (2) a nozzle 9 for supplying the raw water to be filtered is opened downward, (3) the nozzle 9 for supplying the raw water to be filtered is connected to a supply piping 7 for the raw water to be filtered through a stop valve 8 and (4) the uniformity coefficient of the filter material particles is <=1.7.
|
