Design, Realisation and Performance Evaluation of an Optimised Drying Oven for Maize Post-Harvest Processing

Post-harvest losses in maize production remain a major challenge in many developing countries due to inefficient traditional drying methods such as sun drying, which often result in microbial contamination, reduced grain quality, and economic losses associated with high residual moisture content. This study presents the design, realization, and performance evaluation of an optimized drying oven for maize post-harvest processing. The system was designed using functional and structural engineering approaches with modelling carried out in SolidWorks, while airflow and heat distribution within the drying chamber were analysed using computational fluid dynamics (CFD) simulations. The developed prototype features an insulated drying chamber, dual-fan air circulation, and sensor-based temperature control to enhance thermal uniformity and energy efficiency. Experimental drying tests were conducted on 7.5 kg of maize at 50°C, 55°C, and 60°C, with temperature and moisture variations monitored using thermocouples and moisture analysers. Results showed that moisture ratio decreased steadily with drying time, with drying duration reducing from 300 min at 50°C to 240 min at 60°C. The drying process occurred mainly in the falling-rate period, indicating moisture diffusion as the dominant mechanism. Energy efficiency increased from 75.57% to 80.96%, and final moisture content reached the safe storage range of 13-14%. The results demonstrate that the developed drying oven provides an efficient, reliable, and scalable solution for maize drying, contributing to improved post-harvest handling and reduced grain losses.