Modeling batch fluidized bed drying of pharmaceutical powder: Influence of hydrodynamic regime and sorption isotherms

A mathematical modeling, based on the two-phase theory of batch fluidized bed drying of type A particles and type B particles pharmaceutical powders, was performed. A perfectly mixed flow bubbling regime and an axially dispersed plug flow turbulent regime with a freeboard section were assumed. The experiments were carried out in a pilot-scale bed and in an industrial scale bed. The experimental sorption isotherms were used to model the falling rate drying period. The influence of the particles hygroscopic properties on the drying rate and on the temperature profile was discussed. The simulated solid moisture content and temperature profiles are in good agreement with the experimental results.