Design and Evaluation of a Motorized and Manually Operated Groundnut Shelling Machine

Abstract

The traditional method of shelling groundnut has proved to be inefficient, labourious, time consuming and low output. The search for more efficient and cost efficient way of shelling groundnut informs the objective of this paper. A combined motorized and manual operated groundnut Sheller was developed and evaluated. It consists of a feed hopper, frame, beaters mounted on the shaft drum, blower (fan) and a delivery chute. The machine is powered by an auxiliary engine for the motorized part and also by a handle comprising a gear system for the manually operated part. The Sheller was evaluated for percentage nut shelled, shelled nut broken and unshelled pods. The samples used are 10kg and 5kg for the electrically and manually operated parts respectively. Result of the electrically operated Sheller shows that with a mean shelling time of 45s, 4.49kg of nut were shelled with 0.11kg damage, 2.18kg unshelled and 0.67kg of winnowed chaff. The electrically operated Sheller has a shelling efficiency of 78%, cleaning efficiency of 85%, mechanical damage of 1.1% and a capacity of 345.4kg/hr. The manually operated Sheller shows that with a mean shelling time of 63.7s, 2.14kg of nut were shelled with 0.14kg damage and 1.74kg unshelled. It has a shelling efficiency of 65%, a mechanical damage of 2.8% and a capacity of 118.9kg/hr. The Sheller when operated electrically performs better than the manually operated.