Development and Validation of Mass Transfer Model for rough Rice (Sepidrod) Kernel drying

Rapid drying can increase brittleness and induce internal cracks which predispose the product to breakage during subsequent activities. The drying process must be understood and controlled so that design guidelines which reduce or minimize drying damage to rough rice can be established and improved. This study is to give a mathematical model with numerical solution to follow the mass distributions inside a cross sectional area of an individual rough rice (‘Sepidrod’) kernel that it is function of drying time with respect to the effects of the coupled heat and mass transfer processes. The applied drying models are similar to the modified Luikov’s equations Simultaneous heat and mass diffusion in biological materials. This mathematical model can be used for investigating rough rice with different drying characteristics during drying. A finite element formulation and solution of a set of nonlinear coupled conductive heat and diffusive moisture transfer equation to improve grain drying simulation of axisymmetric bodies is presented. Axisymmetric linear triangular elements with two degree of freedom per node are used to discretize the rice grain in both models. The moisture distributions inside the individual rough rice kernels were produced by the model. Good agreement has been observed when the output of nonlinear model was compared to experimental data by others. This comparison showed a no significant statistical difference and Curves of equal moisture inside the grain were plotted during drying.