Experimental and theoretical investigation of hot air- infrared thin layer drying of corn in a fixed and vibratory bed dryer

Drying behavior of corn (Zea mays L) was studied in a hot air-infrared dryer. The effects of inlet air temperature (40, 50 and 60 °C), infrared radiation intensity (1000, 2000 and 3000 W/m2), and modes of drying bed (fixed and vibratory) were investigated on grain moisture variation during drying process. Corn kernels were dehydrated from the initial moisture content of 24.5 ± 0.5% (w.b) to final moisture content of 14 ± 0.2%. The thin layer drying characteristics was experimentally investigated and appropriate mathematical drying models were correlated with temperature and radiation intensity. Among models fitted to experimental data, the Page model was found to be the best model for describing drying behavior of corn in thin layer drying form. The effective moisture diffusivity ranged from 0.6170 × 10−8 to 4.6432 × 10−8 m2/s for the fixed bed mode and 0.8021 × 10−8 to 5.5533 × 10−8 m2/s for the vibratory bed mode.