Comparative performance evaluation of an existing and modified acha dehullers

Abstract

A comparative performance evaluation of an existing and modified acha dehuller was carried out. The modifications undertaken on the existing dehuller were for the cylinder type, cylinder-concave clearance, cylinder speed and hopper opening. The modified acha dehuller was run at a higher cylinder and fan speeds of 2800 rpm as against the existing cylinder and fan speeds of 934 rpm. The performance evaluation for the existing and modified acha dehullers determined were for their throughput, total grain loss, dehulling efficiency, acha recovery efficiency, cleaning efficiency and the dehullers’ performance index. The performance of the existing and the modified machines were compared using t-Test at p≤ 0.05 to determine if the modified acha dehuller was significantly better than the existing machine. The results obtained showed that the modified machine was 30%, 31%, 30%, 22%, 23% and 19% better than the existing machine for percentage of undehulled acha, total grain loss, dehulling efficiency, acha recovery efficiency, cleaning efficiency and dehuller performance index respectively. However, the throughput and percentage of blown acha of the two machines were not significantly different. The modified dehuller showed an improvement over the existing one.

Keywords: Acha, fonio, dehuller, performance evaluation