METHOD AND APPARATUS FOR CONTROLLING NUMBER OF BIOLOGICAL OXIDATION TANK FOR WATER PURIFYING PLANT

摘要

PURPOSE:To contrive to stabilize the quality of treated water, by providing a flowmeter, an air blow amount operation circuit, a biofilm necessary area operation circuit and a number-of-tank determining circuit and changing the contact area of a biofilm. CONSTITUTION:A biofilm necessary area operation circuit adds an inflow amount at the temp. of each raw water to calculate a biofilm contact area and a number-of-tank determining circuit 8-2 calculates the number of necessary biological oxidatation tanks I. A use tank determining circuit 8-3 determines the tank to be used and the unused tank on the basis of the number of the use tanks and an inflow value control circuit 8-4 performs the opening and closing control of an inflow valve 4 so as to hold the state of the tanks determined by the use tank determining circuit 8-3. An air amount regulating value control circuit 8-5 controls the opening degree of an air amount regulating valve 5 corresponding to the amount of air to be respectively sent to the determined tanks to be used and the unused tanks. By this method, an air blow amount is suppressed to a necessary min. degree and power consumption is reduced.