| 摘要 |
<p>PURPOSE:To contrive to make treatment with active sludge highly efficient, by adjusting the mixing ratio of high-purity oxygen gas and air on the basis of the required value of the concentration of oxygen in gas, and controlling the concentration of oxygen in aerating gas while holding the amount of aerating gas constant. CONSTITUTION:A detector 21 for a flow amount and a detector 22 for concentration are provided in a system 2 for supplying water to be purified, and each detection signal from them is taken in a system 7 for controlling concentration in aerating gas. A system 11 for supplying air and a system 12 for supplying high-purity oxygen gas are connected through electromagnetic valves 9, 10 to a line 8 for supplying aerating gas, and the electromagnetic valves 9, 10 are controlled by the system 7 for controlling the concentration of oxygen in aerating gas. The system 7 for controlling the concentration of oxygen in aerating gas calculates the amount of a load on the basis of the detected value of the flow amount and the detected value of the concentration, calculates the concentration of oxygen in gas from the relationship between the amount of the load and the required amount of oxygen predetermined by said amount of the load and sets the concentration of oxygen in aerating gas at the calculated value.</p> |
