Predicting Behavior of Gas-Solids Systems for Non-Uniform Fluidization

A new method was developed to predict the pressure drop and minimum fluidization velocity as a function of inlet gas velocity for multicomponent fluidized beds. The method attributes the changing bed composition during the fluidization process by using a definition for the mass fractions of the bed not yet fluidized. First, a literature survey presents single and multicomponent system correlations that estimate the minimum fluidization velocity. Then, development of the "MASS method" was described and compared to published experimental data and numerical simulations for pressure drop from single-, binary-, and ternary-component fluidized bed systems, where good agreement was observed. Minimum fluidization velocities predicted using correlations in the literature were compared with the MASS method and corresponding experimental data and numerical simulations. The predicted minimum fluidization velocity from the MASS method provided very good results with a relative error of ±4% compared to experimental data. The MASS method was shown to accurately predict fluidization of complex multicomponent systems of granular material and can be used to predict other systems.