OPERATIONAL CHARACTERISTIC EVALUATION OF LIQUID-PUMP TYPE DEEP SHAFT AERATOR

Abstract

The deep shaft has been recently developed as an aeration device to meet high oxygen demand in liquid. The authors reported previously on the result of analyzing operational characteristics of the air-lift type deep shaft aerator.
A similar analysis was carried out for the liquid-pump type shaft, in which liquid circulation between the downcomer and the riser parts in the shaft is maintained by a liquid pump.
As results of the mathematical model simulation, the operating condition which gives a stable liquid circulation, and the optimal power economy condition, which yields the maximum capability of oxygen transfer to liquid per unit power consumption, are made clear. Though the power economy is a little lower than that in the air-lift type shaft, more flexible and stable operations can be expected with the liquid-pump type shaft under varying conditions of oxygen demand in liquid.