PURPOSE: To prevent the degradation of a treatment capacity by controlling the rotating speed of an air blower by the signals from a dissolved oxygen sensor and a temp. sensor in such a manner that the saturation rate of the dissolved oxygen attains a target saturation rate at the time of driving this air blower and executing a sewage treatment by an activated sludge method.
CONSTITUTION: This air blowing device for an aeration tank has the air blower 10 for supplying air via an air diffusion pipe 11 into the aeration tank 1 in which sewage is put. The air blower 10 is rationally driven by a universal three-phase AC motor 13 controlled in rotating speed by means of an inverter 14. The air blowing device is provided with the temp. sensor 15 for detecting the temp. of the sewage of the aeration tank 1, the dissolved oxygen sensor 16 for detecting the dissolved oxygen quantity in the sewage and a target saturation rate setting means 17 for setting the target saturation rate of the dissolved oxygen saturation rate of the dissolved oxygen of the sewage. The output signals therefrom are inputted to a control section 20. The actual saturation rate is calculated from the detected values of the satd. dissolved oxygen quantity and dissolved oxygen quantity based on the sewage temp. and the control value of the inverter 14 is set according to the deviation from the target saturation rate.
FUJINE KAZUE
ITOU YOSHIARI
KAYABA KOJI
| JPS6377593A | 1988-04-07 |
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