Session: 7.3 - Gas-Liquid flows

Paper Number: 158419

158419 - Impact of Liquid Density on Taylor Bubble Dynamics in Airlift Pump: A Flow Visualization Study 

Abstract: 

Airlift pumps are widely utilized in aquaculture, water treatment, and the oil and gas industries for applications requiring simultaneous water circulation and mass transfer. Their ability to handle gas-liquid mixtures without mechanical moving parts offers unique advantage of included reduced maintenance in harsh environments. Also, this makes airlift pumps particularly effective for corrosive fluids, high-density fluids, slurries, and biofouling-laden applications, where conventional pumps face limitations. Understanding the performance of airlift pumps requires detailed characterization of the two-phase flow dynamics within the pump riser, particularly parameters such as slug velocity, slug length, and slug frequency. This will provide valuable insights into the complex two-phase flow mechanisms within airlift pumps, enabling optimized designs for challenging fluid handling applications. This study investigates the influence of liquid density on Taylor bubble behavior in an airlift pump using high-speed flow visualization. Experiments were conducted in a recirculating two-phase flow loop, incorporating an airlift pump equipped with an angled axial air injector. Liquid densities ranging from 1000 to 1100 kg/m³ (adjusted via salt concentration) were tested. Air and liquid flow rates were precisely measured, and the Taylor bubble characteristics were captured using high-speed imaging. Results showed that as liquid density increased, the airflow required to achieve lifting effects also increased, leading to a decline in pump efficiency. Slug lengths were observed to decrease with increasing density, measuring approximately 11 cm and 9 cm for liquid densities of 1000 kg/m³ and 1100 kg/m³, respectively with corresponding slug velocities of 0.9 cm/s and 0.8 cm/s. These findings highlight the dependence of airlift pump performance on liquid density, demonstrating higher pumping efficiency and flow rates at lower liquid densities.

Presenting Author: Josh Rosettani University of Guelph

Presenting Author Biography: