Thermo-Kinetics of The Sun Drying of Plantain Slices Under Forced Convections and Open Air Conditions

The thermo kinetics of the sun drying of plantain slices integrated with the granite sensible thermal energy storage material (GSTESM) were investigated. Fifteen (15) thin layer drying models were adopted to model the drying curves following standard criteria for fitness. The moisture content of plantain slices took 1140 minutes for both open air and solar drying system with plywood drying chamber to reduce from 61.5% to 6.83 and 7.34% w.b. respectively, while it took the solar drying system with Perspex glass chamber 1080 minutes to reduce the same initial moisture content of plantain slices to 6.13%. The effective moisture diffusivities for plantain slices were 17.825 x 10ˉ¹⁰, 14.880 x 10ˉ¹⁰ and 13.662 x 10ˉ¹⁰ for the controlled solar dyers (with Perspex glass chamber, plywood chamber) and open air respectively. The obtained activation energy values for the three drying processes (solar drying with Perspex and plywood chambers) and open air were 22.641, 22.144 and 21.983 kJ/mol. The values of mass transfer coefficient for the dried plantain slices in the solar drying systems (with Perspex and plywood chambers) and open air were 1.246 x 10-6, 1.435 x 10ˉ6, 1.966 x 10-6 m/s respectively. While the heat transfer coefficients were 3.165, 3.0412 and 2.751 W/m2. K. Midilli et al. performed better than the others in describing the drying behavior of the solar drying system of plantain slices using the Perspex glass and plywood chamber, while the model proposed by logarithmic performed better than the others in describing the open air behaviour of plantain slices. Therefore, the obtained results would be useful in the design of solar drying equipment for agricultural products under open air and forced convection mode.