Design, construction and performance evaluation of a rice destoner

Abstract

The market price of local rice in the market is significantly determined by its quality which is dependent on the level of cleaning and some other processing operations. Hence, the need to improve the quality of rice, increase production and reduce human labour has brought about the development of rice destoning machine. Therefore, this study aimed at designing, fabricating and evaluating the performance of a rice destoner. The design was based on the principle of material separation and was constructed from locally-available materials. The machine was powered by a 2hp electric motor and three vibrating screens of varying apertures were used for the upper, middle and lower screens. The machine had an average capacity of 130 kg/h. The performance of the machine was evaluated with 10 kg of Ofada rice at 11, 21 and 25% moisture content (dry basis) and 10 kg of Faro 55 rice at 14, 22 and 27% moisture content (dry basis). The results showed that separation efficiency decreased as the moisture content of rice decreased for both varieties. Cleaning of rice at low moisture content is recommended for optimum performance of the destoner.