A Model for the Dynamics of Spouted Bed Dryers

Abstract

A mathematical model has been developed for unsteady-state operations in spouted bed dryers based on a streamtube concept. This model predicts radial distributions of heat and mass inside the bed using a set of simple plug-flow stream tubes. The model's predicted results for moisture content and air temperature have been compared with the experimental data for drying of green peas in a spouted bed and a good agreement has been observed with a mean relative deviation of 4.4%. When significant radial distributions exist inside the bed, large discrepancies are observed between the streamtube and plug flow models predictions. The discrepancies become wider when lower air temperature and higher air humidity are applied, whereas particle diameter and air flow rate are not effective in a pilot-scale dryer.

Keywords:

• Drying
• Mathematical modeling
• Spouted bed
• Streamtube model

ACKNOWLEDGMENT

The authors gratefully acknowledge Mr. Y. Ghalavand for his assistance during this study.