STABILITY AND HYDRODYNAMICS OF CONICAL SPOUTED BEDS WITH BINARY-MIXTURES

The application of conical spouted beds with binary mixtures of glass spheres of particle diameters between 1 and 8 mm, in stable operation regime and without segregation, has been studied. The effects of the contactor geometric factors (angle, inlet diameter), of the stagnant bed height, of the mixture composition, and of the gas velocity on bed stability and bed segregation have been analyzed. It has been proven that the correlations proposed in the literature for calculation of the hydrodynamics of spouted beds of cylindrical geometry are not suitable for evaluating the hydrodynamics of the operation with mixtures in conical contactors. Original equations for calculation of the minimum spouting velocity, of the maximum and stable operation pressure drop, and of the bed voidage of minimum spouting have been proposed. In these equations the Sauter mean diameter is used as the characteristic diameter of the mixture. A weighted average value of the (drag force)/(gravity force) ratio is used for calculation of the bed voidage of minimum spouting.