| 摘要 |
<p>PURPOSE:To enable the control of the amt. of return sludge with high accuracy with a device for admitting sewage into an aeration tank, treating the sewage therein, conducting the treated sewage into a settling tank and treating the same by automatically calculating a target control valve and correcting the same to a correct value at all times. CONSTITUTION:The time moving average value CA of the concn. of the suspended matter mixture in the sewage in the aeration tank 1 is calculated in an arithmetic means 4. The amt. of the return sludge in the set time determined at the prescribed time is calculated according to the time moving average value of the above-mentioned concn. of the suspended matter mixture in an arithmetic means 5 for the return sludge. The amt. of the return sludge to be returned from the settling tank 2 to the aeration tank 1 is controlled with the amt. OR of the return sludge calculated by the means 5 as a target value in a control part 6. As a result, the high-performance control of the amt. of the return sludge is executed without the cross-interference between the various controls of the sewage treatment device.</p> |
