Experiment were conducted to investigated the flow characteristics of airlift pumps operating in gas-liquid-solid three phase flow by employing a high-speed camera. The results showed that an intermittent flow consisted of film and liquid slug appeared in airlift pumps with a flow frequency of 1.5–2.6 Hz. The portion of slug body directly determined the performance of airlift pumps due to a large particle concentration. In practical engineering, some methods for increasing the portion of slug body could be used for better pump performance.
