Design, Construction and Performance evaluation of a Rice Winnowingg Machine

Abstract

A rice winnowing machine was designed, constructed from locally sourced materials, and tested at three different levels of feed rates (2 kg, 3 kg, and 4 kg), three concave clearances (20 mm, 40 mm, and 60 mm), and three different blower speeds (350 rpm, 630 rpm, and 760 rpm). The maximum separation efficiency was attained at a clearance of 20 mm for all blower speeds (350 rpm, 630 rpm, and 760 rpm) with corresponding efficiencies of 89.76 %, 92.11 %, and 91.59 % while the throughput capacities are 117.17 kg/hr, 115 kg/hr and 109.72 kg/hr respectively. It was observed that 630 rpm blower speed at a clearance of 20 mm is the most suitable for the operation of this machine, as it has a high separation efficiency of 92.11 % with a throughput capacity of 115 kg/hr. It can be concluded, that the developed machine could reduce the drudgery involved in manual winnowing of rice.