Performance Evaluation of a Hybrid Dryer for Grains

The study evaluated a hybrid grain dryer prototype at Ahmadu Bello University, Zaria, Nigeria, in May 2019, focusing on air flow rate (3.6, 4.5, 6.1 m³/s) and grain depth (5, 10, 20 cm) as key factors. A 3×3 factorial experiment in a randomized design assessed the dryer's performance using maize. Metrics included collection, drying system, fuel, sensible heat utilization, and pick-up efficiencies. Data were analyzed using Statistical Analysis Software (SAS 9.0), with Analysis of Variance (ANOVA) and Duncan Multiple Range Test (DMRT) at 1% and 5% significance levels. Results showed collection efficiencies of 19.8%, 15.2%, and 11.2% at 6.1, 4.5, and 3.6 m³/s, respectively; fuel efficiencies were 25.5%, 23.9%, and 23.6%; and sensible heat utilization efficiencies were 68%, 65.6%, and 55.9%. Drying efficiencies were 65.5%, 50.3%, and 45.4% at 5, 10, and 20 cm grain depths, respectively. Pick-up efficiency increased from 1.5 to 1.7 with higher air flow rates but remained constant (1.6) across grain depths. Graphs illustrated drying characteristics, showing relationships between grain depth, air flow rate, moisture content, and time. The study demonstrated the hybrid dryer's performance under varying conditions, providing insights for optimizing grain drying processes.