Performance evaluation and optimization of the maize shelling operation of the multi-purpose farm vehicle
In Uganda, maize post-harvest losses stand at 30% due to poor drying, poor storage and poor shelling techniques amongst other challenges of which shelling stands out as the biggest challenge. Hence the multi-purpose vehicle with a maize shelling operation was developed. On testing the vehicle with the Agricultural Engineering and Appropriate Technology Research Institute (AEATRI) maize sheller at a shelling speed of 870 rpm and 13 % moisture content, the output capacity was 608 below the expected 1,000 . The shelling efficiency was 97. % but the grain damage percentage of 8.43 % higher than acceptable 2 %. The cleaning efficiency was 18.40 % much lower than 98.00 % recommended. The main objective of the study therefore was to evaluate and optimize the multi-purpose farm vehicle maize shelling operation. Basing on the evaluation results, a modified maize sheller was designed and tested using standard procedures. A factorial experiment with shelling speed and moisture content as the main effects at 3 levels for different performance indices was conducted to further evaluate the sheller. Analysis of Variance was done using R-studio and a cost-benefit analysis was also conducted to determine the economic feasibility of the modified sheller. At 870 rpm and 13 % moisture content, the modified sheller had an improved output capacity of 1,581 5.67 , shelling efficiency of 98.0 0.38 %, cleaning efficiency of 98.3 0.17 %, and grain damage of 0.75 0.13 %. For all the treatment combinations, moisture content and shelling speed significantly affected the output capacity, shelling efficiency, cleaning efficiency and grain damage percentage (p<0.05) but moisture content did not significantly affect cleaning efficiency (p>0.05).The payback period of modified maize sheller was 1 year (11 working months) with a benefit-cost ratio of 1.33.