Chemical Engineering Communications, Vol.195, No.9, 1144-1158, 2008
Application of drift-flux model in liquid-solid circulating fluidized bed
Solids circulation rate and solids holdup are experimentally investigated in a liquid-solid circulating fluidized bed that covers a wide range in solid and liquid flow rates, particle size, and density. The drift-flux model, which is extensively used to describe the flow behavior of gas-liquid systems, is modified in the present work and for the first time applied to the experimental data of a liquid-solid circulating fluidized bed. The distribution parameter C-o is evaluated using the drift-flux model from the present experimental data and also from the data available in the literature. It is found from the analysis that the value of the distribution parameter lies in the range of 0.78 to 0.99, which is a reverse trend to the liquid-gas system. The weighted average drift velocity (u(sj)) is well correlated to the terminal velocity of the particle. The solid holdup predicted using this model agrees with the experimental results.
Keywords:distribution parameter;drift-flux model;hydrodynamics;liquid-solid circulating fluidized bed;solids holdup;weighted average drift velocity