Further Theoretical Studies on Rotary Drying Processes Represented By Distributed Systems

Mathematical tools for studying panicle transpon in rotary drying and cooling processes are developed in this paper. In contrast to conventional approaches aimed at deriving empirical or xmi-empirical correlations, a rigorous mathematical analysis which employs dilferential calculus and analytical geometry is emphasis4 in the current research. These developments allow accurale computations of solid flowrate, retention time and particle holdup in rotary dryers with arbilrary flight configurations. Consequently, optimal dryer configuration design in terms of drum dimension, flight number and geometry can be achieved through a better understanding of the mathematical insight of rotary drum performance.

Techniques developed using this method are applied to the distributed parameter model eslablished earlier by the authors (Wang el al., 1993) to replace out-dated correlations for the determination of retention Lime and solid holdup. As a result of the new developments, the distributed parameter approach to the dynamics of rotary drying processes becomes more general and more reliable.