Fundamental study on lifting properties of air-lift in homogeneous environments

Abstract

Flow patterns and lifting properties of air-lifts in homogeneous environments are examined in laboratory experiments. The flow patterns are classified into three ones; bubble flow, slag flow and bubble bullet. It is shown that different flow patterns can appear even for the same air-rate, which influence lifting properties. Critical lift head is formulated from the balance of buoyancy and gravity in air-lift. Non-dimensional air rate, Fb, is derived. Lifting discharge is explained with the balance between buoyancy and wall friction, and it is clarified that the characteristic buoyancy, Mp, and the characteristic Reynolds Number, Rp, are very important parameters for lifting discharge.