38 Numerical Study on Coupled Heat and Mass Transfer in Potato during Hot-Air Drying Available to Purchase

Drying processes are widely used for food production, but a real scientific approach is not yet applied, so rather empiric rulers are used to set up industrial production. This paper concerns the results of the industrial validation of a physically based mathematical model developed to simulate the phenomenon of hot-air drying. Based on thermodynamic theory, a third boundary mathematical model describing the coupled heat and mass transfer inside porous meida during convective drying was developed. An experimental system had been established to validate the precision of dynamic mathematical model. Variable heat and mass transfer coefficient were applied in the model. Variation of both moisture and temperature distributions with drying time inside the product were analyzed by numerical study. The results show that the temperature distribution will affect the heat transfer coefficient and mass transfer coefficient will directly influence on the drying rate. The influence of heat on mass transfer should be considered, on the contrary, the influence of mass transfer on heat can be neglected. This work provid the theoretical and technological basis for study on drying dynamic of the optimization of drying program.