DESIGN, DEVELOPMENT AND PERFORMANCE EVAULATION OF A COMMON BEAN (PHASEOLUS VULGARIS) THRESHER

Abstract

Production activities including harvesting and post-harvest handling of the common beans need great attention to ensure the abundance of the product both in quality and quantity for enhancing food security and income generation. Threshing is one of the post-harvest activities and the traditional threshing method is crude, labor intensive, tedious and time-consuming, and grossly inefficient. In this study, a common bean thresher was designed, developed and tested for its performance. The performance parameters included threshing efficiency, cleaning efficiency, mechanical damage, and throughput capacity at different feed rates and drum speeds. Three levels of the feed rate (120, 140, and 160 kg/hr) and three levels of the drum speed (350, 450, and 550 rpm) were tested under factorial in split-split plot with every trial replicated thrice making a total number of the experimental runs to be 27. Results showed that threshing efficiency and cleaning efficiency increased with increasing drum speed and decreasing feed rate. Mechanical damage and throughput capacity increased with increasing drum speed and feed rate. Maximum threshing efficiency of 99.77 % and maximum cleaning efficiency of 84.48 % were obtained at a drum speed of 550 rpm and feed rate of 120 kg/hr. A maximum throughput capacity of 60 kg/hr was obtained at a drum speed of 550 rpm and a feed rate 160 kg/hr. Results also showed that throughput capacity increased with the increasing speed of the screw conveyor in the anti-chocking unit. Generally, the data obtained from the performance evaluation showed that the machine has performed satisfactorily.