The experimental setup is designed in order to investigate the operation of airlift pumps. The main part of the airlift pump consists of a vertical transparent pipe with a length of 2 m and 31 mm inner diameter.
The upper end of the riser is connected to an overhead-collecting tank where the air escapes to atmosphere and water flow return through a downcomer to collecting tank, where water can be measured using a calibrated scale.
The overhead tank is designed to direct the water to the collecting tank with minimal fluctuations and damp free vortices and thus provides accurate flow rate measurements. The movable water supply tank is used to adjust the submergence ratio. All pipes are made of transparent material to allow for the flow patterns visibility.
Air flows from the air reservoir and measured by the rotameters and air mass flow control. The flow was visualized downstream of the dual injector using a high speed video camera that can operate at speeds up to 10,000 frames/s. Capacitance sensor is also used to measure void fraction in the pipe riser.
The airline is connected to an electrically operated solenoid valve. The purpose of the solenoid valve is to control the pulsating air stream at various frequencies. The solenoid valve opening and closure is controlled by a cyclic timer. All instruments are connected to DAQ system for data capture and processing.