The performance and flow characteristics of swirl flow injector type airlift pump system

Abstract

Sediment from the environmental damage and erosion in the watershed will settle in the bottom of the reservoir. It can reduce the capacity of the reservoir. Airlift pump technology is one effective method for lifting the sediment from the reservoir. The airlift pump has a simple working principle, the pressurized air is injected into a riser pipe containing water, so those air bubbles are created. Air bubbles move upward and it will lift the around liquid due to interface friction. In this present experimental study, the airlift pump was designed by the transparent acrylic pipe with 3.4 m length, and 56 mm inner diameter. Air and water were the working fluid. The water column in the riser pipe was set-up corresponds to the submergence ratio from 0.5 to 0.68, and the superficial gas velocity was changed from 0.00677 to 0.677 m/s. The mouth bell suction head was placed on the lower end of the riser pipe to mounting the two injectors. It was placed on the lower end of the suction head with the 45° direction of the horizontal and opposite output direction to produce the swirl flow. A high-speed camera was used to record the flow pattern. As the results, we know that the higher the submergence ratio, the greater the superficial water velocity at the same of the superficial gas velocity. It is implying the greater the efficiency and effectiveness of the pump. The swirl flow at the suction head is generated when QG>2.8 m3/hr. The consecutive slug becomes the main factor in the existence of the pulsation effect when the pump is operated. The variation of superficial gas velocity is the dominant effect of change in the flow pattern than the variation of the submergence ratio.