| 摘要 |
<p>PURPOSE:To control the quantity of dissolved oxygen at an outflow port and smoothly remove organic matter, by a method wherein an output from a dissolved oxygen concentration meter is inputted into a dissolved oxygen recording controller, and an output from the recording controller is inputted into a ratio setter responsible for the final step of an aerating tank. CONSTITUTION:An inflow sewage quantity signal value detected by an inflow sewage quantity detector 4 is inputted into a sewage inflow pattern memory device 10. A set point for the quantity of air fed into each aerating tank 1 is determined by a method wherein a time delay conforming to each aerating chamber is added to the inflow sewage quantity signal by a time delay calculator 11, the resultant value is inputted into the ratio setter 5 corresponding to each tank, and is multiplied by a fixed ratio. In this case, the ratio in the ratio setter 5 corresponding to the aerating chamber provided at the final stage is determined by an output from the dissolved oxygen recording controller 13 corresponding to the dissolved oxygen concentration meter 12 provided in proximity to the outflow port C of the aerating tank 1. The air quantity set point is inputted into a recording controller 6, is compared with an output signal from an air quantity detector 8, and the opening of each regulating valve 7 is controlled.</p> |
