Experimental Investigation on the Effect of Nozzle Design on Airlift Pump Performance

Abstract Airlift systems are widely used for mass, momentum, and energy transport, particularly in hydrothermal and oil extraction wells. Predicting the impact of nozzle design parameters, such as perforation diameters and air injection areas, remains challenging. This study experimentally investigates an annular airlift pump to understand the influence of various nozzle configurations on performance. Using radial and axial injection with different perforation counts, high-speed camera visualization categorized flow regimes (bubbly, slug, slug-churn) across different gas flow rates. Dimensional analysis assessed energy efficiency, revealing a strong dependence on submergence ratio and perforation-to-inlet pipe area ratio. A dimensionless number, analogous to a restriction coefficient, explained discrepancies with theoretical models at high Reynolds numbers. A specific dimensionless group unified the experimental results for large submergence ratios (greater than 0.8). This study provides insights into optimizing airlift pump performance by exploring the effects of nozzle configurations on transport phenomena.