Prediction of gas holdup in a three-phase fluidized bed from bed pressure drop measurement

Experiments were conducted to investigate the overall gas holdup characteristics in a co-current three-phase fluidized bed with liquid as the continuous phase using air, water and glass beads as the gas, liquid and solid phases, respectively. These studies were carried out in a 0.1 m internal diameter, 1.24 m height vertical Plexiglas column with an antenna type air sparger at different water and air flow rates using four different particle sizes and initial static bed heights. Bed pressure drop measurement was used as the basis for the calculation of fractional gas holdup. From the data obtained through a set of experimental runs, an empirical correlation was developed for the overall gas holdup using dimensional analysis and non-linear regression technique and was compared with some existing correlations. It was found that the gas holdup increased with the flow rate of air and decreased with an increase in the water flow rate.