The Effect of Solid on the Homogenous- Heterogeneous Transition Region in Baffled and Unbaffled Bubble Column with Non-Newtonian Liquid


This research shows a comprehensive study on the effect of solid loadingand non-Newtonian liquid on the hydrodynamic parameter of gas holdup as wellas the critical values of gas holdup and gas velocity of transition zone fromhomogenous to heterogeneous region in both baffled and unbaffled babblecolumn.The experiments were carried out using column of 15cm inside diameter and 2mheight with aspect ratio (L/D=4.5) using perforated plate gas sparger 54 holes withsize equal to 1mm diameter and with free area of holes to cross sectional area ofcolumn 0.24.The three phase system consists of air-non Newtonian liquid of polyacrilamined(PAA) –solid of alumina particles. The measured values of gas holdup andtransition points of gas holdup and gas velocity were compared with differentvalues of PAA concentration (0, 0.01, 0.05 and 0.1)wt% and four values of solidloading (0, 3, 5 and 11)wt% in baffled and unbaffled column.The results show that the transition values of gas holdup and gas velocitydecreased with increasing of PAA concentration under constant values ofNewtonian liquid while they dis approved with non-Newtonian liquid.The solid loading shows an unstable influence of decreasing and increasing of thecritical values in all PAA concentration and in both baffled and unbaffled column.First, these values decreased when solid loading in the range (0-3)wt% then theyincreased with increasing of solid loading from 3wt% to 11wt%.