Hydrodynamics of three phase fluidized bed using low density particles

Gas–liquid–solid fluidized beds are widely used in the petrochemical, pharmaceutical, biotechnology, food and environmental industries. Fluidization is dependent on effective contact between the phases.A three-phase (gas-liquid-solid) fluidized bed is used to study the hydrodynamic characteristics of low density particle (wood) using water as liquid phase and air as the gas phase.The fluidized bed consists of three sections, the test section, the gas-liquid distributor section, and the gas-liquid disengagement section.The hydrodynamic characteristics determined included the bed pressure drop, minimum fluidization velocity and bed expansion ratios. The dependence of these quantities on particle diameter, initial static bed height, liquid velocity and gas velocity has been discussed.Results indicate that the bed pressure drop and minimum fluidization velocity decreases with gas velocity but increases with particle size. Bed expansion ratio increases with increase in the values of the liquid but decreases with dp and initial static bed height.Model equation have been developed from factorial design analysis for predicting the values for bed expansion ratio and predicated values have been found to agree well with theexperimental results.