| 摘要 |
<p>PURPOSE:To save energy consumption of a blower, by wholly opening a control valve at the inlet of an aeration vessel and controlling a suction opening rate of a blower so as to keep a dissolved oxygen amount at a constant level. CONSTITUTION:A dissolved oxygen amount in a sewage is detected by a meter 9, inputted to a dissolved oxygen controller 11 and fed to a flow rate controller 12. The controller 12 computes a valve opening rate proportional to an input signal 10, and outputs the opening rate to a blow rate control valve 6. At the same time, a blow rate is detected by a blow meter 8, and controlled at a constant level by the controller 12. On the other hand, the dissolved oxygen amount, an air blow rate signal 20 and an air pressure detected by an anemometer 13 are inputted to a controller 19 for controlling the operation of a blower, to generate an output signal 24 so that the blow rate control valve 6 will be opened to a possible extent. The opening rate of a control valve 17 is determined to keep the signal 24. Consequently, a pressure loss caused by the valve closing is lowered and energy consumption is saved.</p> |
