Maximum Semi-fluidization Velocity of Gas-liquid-solid Semi-fluidized Beds

Semi-fluidized beds are found to have wide applications in process industries. In the present study hydrodynamic viz., maximum semi-fluidization velocity of gas-liquid-solid semi-fluidized bed has been studied. The necessity of generalized correlation for the prediction of maximum semi-fluidization is emphasized. Experiments have been conducted in a 100 mm ID, 1.8m height vertical Plexiglas column using air, water and solid (of different densities) in order to develop a good understanding of each flow regime in gas-liquid-solid semi-fluidization. It is found that maximum semi-fluidization velocity is strong function of superficial gas velocity, particle size, particle density and bed expansion ratio. Values of the maximum semi-fluidization velocity, obtained from experimental investigations have been compared with calculated values.