| 摘要 |
<p>PURPOSE:To perform quantitative control of activated sludge with high accuracy and stability by coordinating a control loop for accumulation of sludge in a settling basin, a control loop for period of stagnation of sludge, a control loop for return sludge rate and other control loops mutually. CONSTITUTION:The signals from a flowmeter 1 and a densitometer 2 and the signals of a return sludge flowmeter 8, a densirometer 10 and a withdraw flowmeter 11 are inputted to an aeration tank simulation program 13, by which MLSSconcn. are calculated. This value is inputted together with the signals of the flowmeter 1, the flowmeter 8 and the flowmeter 11 to a settling basin simmulation 14. The results thereof are fed to the 2nd operator 16, by which the amt. of the sludge accumulating in a settling basin 4 is calculated. This value is inputted to the 2nd controller 20 which calculates the rate of increase or decrease correction for the flow rate of return sludge. Further, the output of the controller 20 is fed to the 6th operator 21 having the contacts permitting setting of permissible upper and lower limit values of the amt. of sludge accumulated in the settling basin, and if the upper and lower limit values are display device 22 is operated.</p> |
