| 摘要 |
<p>PURPOSE:To prevent an unnecessary activation of an air blower, generated at the time of overshoot, etc., of a DO controller. CONSTITUTION:The controller is provided with an operation controller 13 for activating and stopping plural air blowers, and an operating set number arithmetic means 11 for calculating the number of requested operating sets with respect to the requested air quantity from a DC controller 10 of an aeration tank 4. In the case the number of requested operating sets is smaller than the number of present operating sets, a decrease command of the number of operating sets is outputted to the operation controller 13 from an operating set number deciding means 12. In the case the number of requested operating sets is larger than the number of present operating sets, an increase command is outputted to the operation controller 13, when a DO value tends to decrease, and the increase command is outputted after a prescribed time elaspses, when the DO value tends to increase.</p> |
