Development and performance evaluation of a low-cost motorised wooden maize sheller

Abstract

Shelling is one of the most important post-harvest processes carried out on maize, Given the relatively high cost of available maize shellers usually made of mild steel, maize shelling is largely done small-scale processors by hand in many developing countries. The aim of this study, therefore, was to develop a low-cost motorized maize sheller built largely with sawn-wood of Cordia millenni. The wooden components of the sheller included the hopper, the main frame, the shelling drum housing, and the cleaning unit housing. The cost of a one-off version of the sheller, driven by a 5hp electric motor was N70,000 (US $200) compared to the market price range of US$400 to US$500 for the metallic version in Nigeria. The performance of the sheller was evaluated using yellow maize (Zea saccharata) variety at 13% moisture content. The results obtained indicated that its output capacity (118.9 Kg/hr), shelling efficiency, cleaning efficiency, grain recovery, and total grain losses of about 79 %, 96 %, 91% and 2.8% respectively at a shelling speed of 536 rpm are comparable to similar shellers made entirely of metallic parts. To enhance durability, it is recommended that the sawn-wood for the fabrication of the wooden components should be fully dried before use and/or be painted over with aluminium paint after installation.