Prediction of Bed Expansion in Unpromoted and Promoted Gas-Solid Fluidized Beds

Abstract

Correlations have been developed for the prediction of bed expansion ratio in the line of the Godard-Richardson equation (1969) for unpromoted as well as promoted beds. The correlation factor 'm' of the Godard-Richardson equation has been expressed as a function of promoter parameters for promoted beds in addition to bed parameters as in the case of unpromoted beds. Three correlations for 'm' have been proposed for unpromoted and promoted beds with rod and blade promoters. The comparison of the results reveals that the Godard-Richardson equation is more suitable for unpromoted beds in the original form. In the case of promoted beds, the prediction deviates from the corresponding experimental values due to poor representation of flow parameter. Hence, the flow parameter of the Godard-Richardson equation has also been modified for beds with rod and blade promoters. A comparison has been made between the predicted values of bed expansion using the modified Godard-Richardson equation and the predicted vlaues obtained by correlations developed by Kumar and Roy (2002a) and the corresponding experimental values.