Electronic Thesis and Dissertation Repository


Master of Engineering Science


Chemical and Biochemical Engineering


Jesse Zhu

2nd Supervisor

Dominic Pjontek



A novel cylindrical gas-driven gas-liquid-solid spouted bed was developed in this project, which has a high potential to be used for a biological wastewater treatment process. Solids motion, flow regimes, and regime transitions in this system were studied. With increasing gas velocity, four regimes were identified, including: fixed bed, semi spouted bed, full spouted bed and internal circulating fluidized bed. The respective gas velocities for the transitions between the four regimes were experimentally identified and termed as minimum spouting velocity, full spouting velocity and minimum circulating velocity. A new “basketing” method was adopted to measure the minimum spouting velocity while the particle velocity and dense phase retraction in the annulus were monitored to determine the full spouting velocity and minimum circulating velocity. The effects of key operating parameters on the three transitional velocities were examined in this novel spouted bed. When a draft tube was present, these three velocities increased with increasing particle density and draft tube length. The minimum spouting velocity and full spouting velocity were not affected when varying the nozzle-tube gap, while the minimum circulating velocity increased with longer nozzle-tube gaps. Without a draft tube, the gas-driven gas-liquid-solid spouted bed stability is reduced, where results were mainly obtained in terms of the water level, initial static bed height and gas flowrate.