Performance assessment and optimization of maize dehusker cum sheller - A technology for Northern Transition Zone of Karnataka

Abstract

Maize (Zea mays L.) is one of the major crops in Karnataka state grown for commercial and seed-production purpose. In Northern Transition Zone (Hyderabad-Karnataka region), the major farming sizes of land are limited small to medium holding and they were in the need of economical technique for maize dehusking and shelling operation suited to medium capacity. In present study, the medium sized electric motor (2.23 kW) operated maize dehusker cum sheller (MDS) was developed and evaluated for selected operational parameters, viz. cylinder peripheral speed(6.2, 6.6, 7.1 and 7.6 m/s), concave clearance (20, 25, 30 and 35 mm) and feed rate (400, 600 and 800 kg/h). The machine performance parameters revels that, the dehusking efficiency and shelling efficiency were showed increasing trend with cylinder peripheral speed (S) from 6.2 to 7.6 m/s; whereas decreasing trend against increase in Concave Clearance (C) from 20 mm to 35 mm. The total losses of grains in machine were found lowest between feasible at 25 to 30 mm of C for all feed rates (F). In seed-quality parameters, the decreased germination percentage with increase in S was observed. The increased broken grains (%) and seed-coat damage (%) were identified with increased inS and decrease in C as well as F. The highest desirability value (obtained from numerical optimization technique) was obtained for operational parameter combination of S at 7.1 m/s with C at 25 mm under 600 kg/h of F. The total cost of the MDS was ` 34500 with benefit-cost ratio of 2.24. The performance of machine was also satisfactory for producing maize seeds for seeding purpose without compromising its performance.