Gas-induced fluidization of free settling and free rising particles in liquid batch operation
Abstract
A three-phase system consisting of free settling and free rising particles were fluidized in tandem with gas bubbles in a liquid batch operation. Hydrodynamic properties were investigated, using one kind of heavy particles (ρH=1050kg/m3) and three different kinds of light particles (ρL=930-880kg/m3. Gas holdups are inferred from measured pressure drop and increased with superficial gas velocity (Ug), axial location, particle loading and decreasing densities of the free rising particles. The volume fraction of free settling particles over total particles were measured and then used to calculate particle holdups of free settling and free rising particles. The axial distribution of the solid holdups transferred from higher in the lower sections and lower in the top sections under low Ug, to axially uniform under moderate Ug, then became lower in the bottom section and higher in the top section under high Ug.