MODELING AND SIMULATION OF BATCH AND CONTINUOUS FLUIDIZED-BED DRYERS

The performance of batch and continuous fluidized solids dryers has be en modeled, with allowance for diffusional moisture transport in the d ense phase particles and for interstitial gas-to-particle mass transfe r within the dense phase, as well as for interphase exchange resistanc e between gas bubbles and the dense phase. Two types of boundary condi tions are employed. Variations of the bed temperature and product mois ture content in the bed with time are predicted numerically under vari ous batch drying conditions. Exit product moisture contents, bed tempe ratures and outlet air humidities are also predicted for continuous dr ying at various mean residence times. The model can be used for homoge neous as well as bubbling fluidized bed drying. It can be used for a w ide range of materials, including cereal grains and granular synthetic polymeric materials.