Design and Development of Maize Sheller Machine for Small and Marginal Farmers

A maize shelling machine was designed and developed, which comprised of a frame, a feeding channel, a shelling cylinder and a shaft along with the helical ribs on the cylinder. The three openings were made in the machine for entering the unshelled cobs, grain outlet and shelled cobs outlet. A concave clearance is placed upward for separating grains out of the whole cobs. The machine is operated by an electric prime mover, in conjunction with different belts and pullies of different sizes. The developed maize sheller was then evaluated by changing with varied rotational shelling speeds of 300, 400, 500 and 600 rpm and different concave clearance of 15, 20, 30 and 40 mm. The performance parameters like shelling rate (kg/h), shelling efficiency (%), unshelled grain (%), grain damage (%), power requirement (kW) and germination percentage (%) were calculated for each combination and data compared statistically for standardization of combination in order to get maximum whole grain output, minimum grain damage with high shelling efficiency. The shelling rate (kg/h), shelling efficiency (%) and grain damage (%) increased with increase in the shelling speed for all the treatment combinations under study. It was observed that the shelling rate increased with increase in the quantity of feed while shelling efficiency and grain damage decreased with increase in the quantity of feed. The optimum performance obtained during the evaluation of the machine with grain damage of less than 0.81%, germination count of more than 95%, shelling rate of 218.30 kg/h and higher shelling efficiency (97.5%) was obtained at treatment combination of N3C3 (N3 =500 rpm, C3= 30 mm concave clearance). Therefore, operating the machine under optimal conditions proved effective in delivering an efficient sheller suitable for small and marginal farmers.