Bed hydrodynamics of a new three-phase fluidized bed flotation column with steel ball particles

Abstract

The new three-phase fluidized bed flotation column (TFC) hydrodynamics characteristics, such as gas holdup, bubble diameter and bubble surface area flux have been carried out, and this study focuses on bed fluid hydrodynamic parameters of the TFC. The bed hydrodynamic characteristics viz., bed fluctuation ratio (r), bed expansion ratio (R) and bed voidage (ε) of the TFC have been studied using air as the discontinuous phase and water as the continuous phase, respectively. The effects of the system parameters studied include superficial gas, liquid velocities and initial static bed height (H0). Experimental studies based on the Response surface methodology (RSM) have been made to investigate the mathematical model of hydrodynamic parameters (r, R, ε) and bubble diameter (Db) of the TFC. The results show that the models which were established by operating variables can predict the r, R, ε and Db of the TFC well. Based on the previous investigation of the optimization of bubble performance parameters which has been caried out by Liu et al. (2020), the correlation of Db has been carried out, and the result shows that H0 is the boundary condition that determines the variation of Db. The optimization of Db by RSM shows that relatively small bubbles can be obtained when H0 is greater than 0.290 m within the range of parameters studied. The values of the experiment have been compared with those predicted by the proposed models and have been found to agree well.