Determination of Kinetic Parameters for Thin Layer Drying of Corn

Drying is the removal of a liquid from a solid by evaporation. The main purpose of dehydration is to extend the shelf life of foods while preserving their nutritive values and seed germination properties. To achieve this purpose, the process must take place under optimum operating condition and efficient drying rate. This research work aimed at determining the kinetic parameters for thin-layer drying of corn under constant drying conditions necessary for the design of industrial dryer. An experimental work was carried out using an oven drying method which observed the drying of the grains to be in the falling rate periods at temperatures of 45OC, 50OC, 55OC and 65oC. The rate of drying was found to have a direct relationship with moisture content and temperature but an inverse relationship with time. The experimental data for corn could fairly be predicted by the Page equation. The values of A and B from the Page equation were found to be functions of temperature rather than mere constants as were used in the model and these were for A between 7.23E-04 and 6.59E-06 for the given temperature range while for B it was between 0.67 and 1.31 for the temperature range. Temperature, therefore, is then the most obvious and important parameter to be manipulated in any dryer design especially for hygroscopic grains like corn.