MODELING DIFFUSION-LIMITED DRYING BEHAVIOR IN A BATCH FLUIDIZED-BED DRYER

Fluidized bed dryers are often used to extract water from granular mat erials. When the drying process is mainly limited by the resistance ag ainst water transport inside the particle the drying behaviour is said to be diffusion-limited. In the literature there are several models t hat predict this drying process with very diverging results. In this s tudy a model is set up to arrive at a better prediction for this dryin g process. The heat and mass transfer in the granular material and the drying air is described. The resulting equations are solved numerical ly. The model must be extended to incorporate the heat capacity of the dryer.