| 摘要 |
PURPOSE:To save operating manpower and improve treatment accuracy by automatically controlling the rates of injection of a flocculant and a flocculating assistant according to the changes in the concn. and flow rate of raw water. CONSTITUTION:A change-over device 19 changes over the outputs of a raw water concn. sensor 14 and a sludge concn. sensor 17 by the commands of an arithmetic control unit 18, thereby converting these and outputting the same to said unit 18. When the unit 18 requires both outputs of the sensor 14 and the sensor 17, the outputs of both sensors 14, 17 are converted and outputted alternately. The unit 18 is inputted with the outputs of a flow meter 13, a switch 19, a turbidometer 15 and a pH meter 16, and controls the discharge of a flocculant injecting pump 10, that is, the amount g1 of injection of the flocculant, the discharge of a flocculating assistant injecting pump 11, that is, the amount g2 of injection of the flocculating assistant, and the discharge of a sludge feeding pump 12, that is, the amount gS of the sludge. |
