Development and performance evaluation of low-cost cylinder type maize sheller for small farmers of Jammu and Kashmir

A study was conducted to utilize physical attributes and engineering parameters of local maize varieties (white, yellow and multi-coloured) to develop a power operated maize sheller for small farmers of Jammu and Kashmir. The moisture content measured was within 13-14% limit for all the three varieties. Tri-axial dimensions in terms of length, diameter of maize cobs, eccentricity index, sphericity of maize grains and engineering parameters of bulk density of cobs, angle of repose of maize cobs and grains were used to select the design values of functional components of maize sheller. The maize sheller comprised of feeding hopper, cylindrical drum, beaters, sieving unit, outlet for maize cobs and grains. The performance of the maize sheller was evaluated in terms of variety, RPM and type of beater. The optimization of the response parameters using Design expert 10.0 revealed that RPM of 720, closed chain type beater resulted in 96.01% shelling efficiency, 24.23 kg h^-1 shelling capacity, 3.08% unshelled grain percentage, 1.67% mechanical damage percentage, 98.91% cleaning efficiency, labour requirement of 2.83 man-minutes kg-1 and 95% germination percentage for yellow maize variety. The economic analysis revealed that operating cost was 78.74 Rs. h^-1 with break-event point of 9052.0 Kg, benefit-cost ratio of 1.30:1 and 585.2 hours payback period. The unit cost of maize shelling was calculated as Rs. 3.42 per kg. The maize sheller can be useful to cater to the needs of small and marginal farmers and provide entrepreneurship opportunities to the rural youth of Jammu and Kashmir.