Design, CFD Simulation, Prototype, and Experimental Investigation of Indirect Active Solar Dryer for Banana

Abstract

Indirect active tray solar dryer was designed, CFD simulated, and constructed for the drying of banana in Addis Ababa, Ethiopia. The experimental investigation was done after the CFD ANSYS Fluent simulation of different parameters based on the uniformity temperature and air flow distributions on the symmetry plane. The performance of the designed solar dryer was compared with that of the open sun dryer method, based on drying rate, moisture ratio, and moisture content on a wet and dry basis. From fourteen different mathematical drying thin layer kinetics models, the maximum correlation coefficient of 0.999574, the minimum root mean square of 0.0001352, and the minimum reduced chi-square of 0.007353 were obtained for the Verma et al. model for the slice banana in the designed active solar dryer. Recycling the air from the outlet of the drying chamber on the first day is not possible because the quality of the air is lower when compared with ambient air. The outlet air temperature and relative humidity of the drying chamber were 4.39℃ higher and 8.24% lower than the ambient air temperature and relative humidity respectively, so it is possible to recycle the air after the first day. The average moisture content removed from the product in the designed solar dryer and open sun dryer was 68.01% and 51.01%, respectively, in the 22 and half5 drying hour. The difference between the maximum and minimum moisture removal was 4.47%. It indicates there is a uniform drying in the designed solar dryer. The overall solar air collector efficiency was 33.80%and the maximum drying efficiency was 31.10 %.