Aeration system for activated sludge basin - using air pressure feed to injector equal to hydrostatic pressure

摘要

An aeration system for an activated sludge basin consists of an air lift pump and an injector on its delivery side which can be arranged inside or outside the basin. A perforated pipe is anchored to the bottom of the basin; its discharge forms with the suction port of the pump a short circuit by a round flow in the basin. The compressed air pressure upstream of the injector is at least equal to the static pressure of the liquid column above the lowest point of the injector. The system needs no moving parts which could be damaged by the formation of ice or water level fluctuations. The simple design and little material needed facilitates its rapid installation and use for existing overloaded plant.