PERFORMANCE OF SINGLE AND MULTISTAGE SPOUTED BED DRYING SYSTEMS

A mathematical model is developed to predict the performance of single -stage and multi-stage drying systems using spouted beds. The model us es unsteady state analysis for batch operation to simulate the steady state operation of a continuously fed spouted bed. A parametric study is carried out to study the effect of the following parameters on the performance of a single-stage grain drying system: air flow rate per u nit mass of the grain in the bed, ambient air temperature and humidity , initial and target moisture contents, the residence time in the bed, and the effectiveness of the heat exchanger to recover the thermal en ergy in the exhaust air. The parametric study is also extended to inve stigate the effect of these parameters (except ambient air temperature and humidity) on the performance of the multi-stage system. In additi on, the number of stages is also included in the latter study. The res ults are presented in terms of charts which may be adopted for the des ign of such systems.