Drying saturated zeolite pellets to assess fluidised bed performance

This work studies the drying rates of zeolite pellets (Type 1 [D.M. Ruthven, Principles of Adsorption and Adsorption Processes, John Wiley & Sons, New York, 1984]) in spouted beds and in conventional fan assisted ovens. Three temperatures were studied: 48, 85 and 133 °C for drying times up to 1 h. Heat transfer is deduced from measured mass transfer rates and literature correlations. Maximum heat transfer coefficients were found to be 115.6 W/m2 K for the fluidised bed and 31.8 W/m2 K for the oven using correlations from literature. Higher figures were found by experimentation and calculation, typically about 200 W/m2 K. A finite element model was used to estimate the temperature profile within pellets, the predictions agree well with experimental temperature measurements.