| 摘要 |
<p>PURPOSE:To obtain a withdrawn sludge flow amount controlling apparatus capable of correcting a stayed sludge amount by providing the first operating portion displaying the elastic coefficient and the stress relaxation coefficient as a function of a sludge concn., the second operating portion estimating an interface precipitating speed of a sludge liquid flowed into a final precipitating pond, the third operating portion estimating a stayed sludge amount within a precipitating pond and a regulating portion controlling a withdrawn sludge flow amount. CONSTITUTION:If the MLSS 12 of a sludge liquid flowed out from an aerating tank 2 and the interface precipitating speed 10 of a sludge liquid flowed into a final precipitating pond 3 are periodically estimated and the measured value is applied to an operating portion 11, the elastic coefficient and the stress relaxation coefficient are calculated as a function of a sludge initial concn. On the other hand, if practically measured values of an inflow sewage amount 13, a return sludge flow amount 14 and a withdrawn sludge flow amount 7 are applied to an operating portion 15, a stayed sludge amount within a precipitating pond is calculated. Subsequently, these values are compared to an upper and a lower limit value preliminarily set to a comparing circuit 18 to calculate a corrected amount of a withdrawing sludge flow amount in an operating portion 20 and a withdrawing valve 22 is controlled through a regulating portion 21.</p> |
