DEVELOPMENT AND PERFORMANCE EVALUATION OF A CENTRIFUGAL AIR-FLOW GRAIN CLEANER

Global demand for high-quality grain underscores the need for clean grains which is vital to food security. Contaminants such as broken cobs, grain dust, stones, and chaff are found in grains during harvest, handling, and storage operations. Manual winnowing is laborious and cannot meet the continuous demand for clean grains. The availability of grain cleaning machines will ensure a sustainable supply of clean grains while conserving human energy and improving food security.A centrifugal flow grain cleaner was developed with major components such as hopper, sieves, electric motor, and blower. Yellow maize variety (Swan 2) was used to test the centrifugal flow grain cleaning machine and trials were carried out in three replicates. It was tested at three moisture content (MC) levels of 15%, 17%, and 19% (wet basis) commonly found in grain markets in Ibadan, Nigeria. Three feed rates (FR) (180, 250, and 320 kg/hr) were used. Performance evaluation to determine the cleaning efficiency (EG), total efficiency (ET), and product purity (PP) level using NIS 320: 1997 Seed/Grain Standards and other relevant indices. Analysis of variance was carried out to assess the significance of the models developed using Design-Expert® software (Version 6.0.6 StatEase, Inc., Minneapolis, Minn.). Results showed that EG was within 98.3% to 98.9% across the MC and FR. The optimal ET was 85.5% at optimum operating parameters of 180 kg/hr FR, and 15% MC. The regression model developed for the relationship between MC and FR on EG was significant. Commercial production of the grain cleaner is viable due to its low cost, local technology and, increased demand for quality grains.