Performance Evaluation of a Small-Scale Sunflower Thresher

Threshing and cleaning are two final operations required for the production of high-quality seeds. Nigerian farmers utilize the traditional methods of threshing sunflower which are a disadvantage in the level of seed quality produced. Against this background, a sunflower thresher was developed and evaluated at seven different cylinder speed (400rpm, 450rpm, 500rpm, 550rpm, 600rpm, 650rpm, 700rpm) and two feed rates (2kg/sec, and 4kg/sec). Performance parameters for the study were threshing and cleaning efficiencies, scatter loss, mechanical grains damage and throughput capacity. The evaluation results show a maximum threshing efficiency of 89% and cleaning efficiency of 75%, minimum scatter loss of 0.39% and maximum grain damage of 0.06% and an average throughput capacity of the thresher was 96.7kg/hr, of seed. The best combination of threshing efficiency 89%, cleaning efficiency 75%, scatter loss 0.67%, mechanical grain damage 0.05% and throughput capacity 137kg/hr, were obtained at 700rpm cylinder speed and 2kg/sec. feed rate. Based on the results for the evaluation obtained, the developed machine whose estimated cost was N125,000:00, is recommended as suitable for small scale sunflower producer.