Adaptation and Evaluation of Power Operated Grain De-huller

Dehulling is a process employed to get rid of the outer pericarp and testa of most cereal grains, using mechanical means. Despite the increase in production, limited effort has been taken to improve grain processing technologies, particularly, for small-scale rural farmers. The use of dehuller improves the physical appearance and the functional property of grain. A grain de-hulling machine consists of a hopper and a power-operated mechanism. The performance of the adapted machine was evaluated in terms of de-hulling efficiency, Percentage of breakage, and de-hulling capacity. The maximum de-hulling capacity (500.00 kg/hr and 571.42 kg/hr) was obtained at an operating speed of 2500 rpm and 20 kg of hopper loading for barley and rice respectively. The maximum de-hulling efficiency (99.21% and 97.02%) was recorded at 10 kg of hopper loading and 2500 rpm of the operating speed for barley and rice respectively. The maximum percentage of breakage (2.85%) was recorded at 20 kg of hopper loading and 2500 rpm of the operating speed for barley. For rice, the maximum percentage of breakage (5.02%) was recorded at 20 kg of hopper loading and 2500 rpm of the operating speed. De hulling efficiency, in general, increased when increasing the speed of the machine and decreased when increasing the feeding rate. The broken percentage of the grains increases when the speed of the machine increases and decreases as the feeding rate increases for each grain. The dehulling capacity of the machine increases as both the feeding rate and the operation speed increase for each grain. The adapted machine was good for barley at 2500 machine speed and 20 kg of hopper loading. Since maximum grain breakage was recorded for rice, it is recommended for further modification.