Evaluation of the Milling Efficiency of a Locally Fabricated Grain Mill in Adamawa State

Access to affordable and efficient grain milling technology is a critical constraint for smallholder farmers and rural food processors in Adamawa State, North East Nigeria, where distances to commercial mills impose significant time and cost burdens. This study evaluates the performance of a locally fabricated hammer mill designed for small-scale grain processing, testing its milling efficiency for sorghum, millet, and groundnut cake. Performance parameters evaluated include milling capacity (kg per hour), milling efficiency (percent), particle size distribution, energy consumption (kWh per kg), and noise level. The mill was fabricated at a metalworking workshop in Yola from locally available steel, with specifications designed for operation on single-phase electricity. Performance tests were conducted at three screen sizes (1.0, 1.5, and 2.0 mm) and two moisture content levels per grain type. Results indicated a milling capacity of 85 kg per hour for sorghum at optimal conditions, with milling efficiency above 90 percent for all three crops. Energy consumption was competitive with commercially available mills of comparable capacity at 0.12 kWh per kg. Particle size distribution met the specifications required for composite flour applications. The study draws on recent literature on small-scale grain processing technology for sub-Saharan Africa. Findings provide a technical basis for wider adoption of locally fabricated milling equipment in the North East zone. Keywords: hammer mill, milling efficiency, grain processing, fabrication, Adamawa State