CONTACT DRYING MODELING OF AGITATED POROUS ALUMINA BEADS

Contact drying of porous alumina beads (hygroscopic material) was studied at atmospheric pressure in an agitated laboratory disc dryer in order to have a better understanding of the heat and mass transfer phenomena occuring during the process. Drying kinetics and temperature profiles were determined as a function of operating parameters, namely, the initial moisture content, the plate temperature and the agitation frequency. These data (drying kinetics, temperature profile) were modelled using a contact drying model adapted to this hygroscopic material. The experimental data which are a function of two main parameters, namely, the plate temperature and the stirrer rotation speed, were in good agreement with the model prediction.