EFFECTS OF HIGH-FREQUENCY ELECTROMAGNETIC-FIELD ON HEAT-SENSITIVE MEDIA .2. DRYING KINETICS AND SIMULATION

Drying of heat sensitive materials may be performed with the use of co upled microwave and convective energy input. Drying kinetics have been studied in a closed cycle drying tunnel at different ratios of microw ave and convective energies for gelatin film and polyacrylamide sphere . Four zones of drying curves can be distinguished. Continuous microwa ve energy input results in overpressure period, a '' hump'' in the dry ing curve. Overheating may be avoided by automatic control of the dryi ng process. A uniform temperature distribution has been considered wit hin the material for simulation of drying process. Simulation was perf ormed with the enthalpy balance, the isothermal and non-isothermal mod els, respectively.