| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a device for controlling a water level of an oxidation ditch which keeps the load acting on a vertical shaft type aerator in a proper range and stabilizes the operation of the vertical shaft type aerator. SOLUTION: A water gauge 18 for detecting the water level of mixed liquid in a circulating water passage 4 is disposed in a oblong vessel 2. The output of the water gauge 18 is connected with a control unit part 19 and a water level detection signal from the water gauge 18 is sent to the control unit part 19. The control unit part 19 controls the water level of the mixed liquid in the circulating water passage 4 so as to prevent an impeller 10 from sinking in the mixed liquid and, at the same time, controls the water level of the mixed liquid in the circulating water passage 4 in such a manner that the load acting on the vertical shaft type aerator 5 is lowered below the specified value in accordance with a water level detecting signal outputted from the water gauge 18. The control unit part 19 further regulates the quantity of water which overflows over the upper end part of an overflow gate 15 and controls the water level of the mixed liquid in the circulating water passage 4 by controlling the actuation of a motor 17.</p> |
