Performance Evaluation of Grain Pro Collapsible Natural Convection Solar Dryer for Maize Grain Drying in Ethiopia

Even though the production of maize in Ethiopia is highest, its post-harvest loss is very high that estimated as high as 19.8%. Post-harvest loss of maize occurred at each post-harvest activity along the value chain. In Ethiopia, high loss of maize is incurring during threshing, drying, and storage. Open sun drying/sun drying is the only drying system before and after harvesting of maize that results from 5.8% to 17.4% loss. Thus, it is very important to dry maize using an appropriate dryer to minimize this loss during storage and drying itself. The main objective of this study was to investigate the performance of a collapsible dryer for the drying of freshly harvested maize grain. Collapsible dryer is an affordable and portable dryer that can dry various agricultural products safely and conveniently. The performance of the collapsible dryer was tested using a sample load of 500 kg (10.45 kg/m2) freshly harvested maize grain with a variety of BH-540. During the drying period, drying air, relative humidity and temperature (both loading and unloading condition), and maize grain moisture content were measured continuously and total energy consumption and drying rate were computed. In addition, the temperature and relative humidity of the experimental environment were measured. The performance of the collapsible dryer was compared with open sun drying system for maize grain. The result revealed that the drying time required for maize grain dry to 14% moisture content (w.b.) in collapsible and open sun drying system were 26 and 74 hours, respectively. The hourly moisture removal rate was found 0.17 kg moisture/hr. and 0.062 kg moisture/hr. in collapsible and open sun drying, respectively. The drying efficiency and total energy consumed by the collapsible dryer were found to be 76.25% and 169.65 MJ, respectively. The performance of a collapsible dryer was better than open sun drying for maize grain drying, and this technology could be considered as a good option for the drying of grain to reduce the loss.