Design & fabrication of a motorized groundnut shelling machine.

Abstract

The traditional way of removing kernel from groundnut is to crack it with hand but when a large amount of groundnuts have to be work on this method is time consuming so a Sheller machine has to be used. In Uganda due to heavy demand of groundnut there is a need of shelling the groundnuts and obtaining the peanuts in safe, fast and economic form. There are different methods of shelling ground nuts, different machines have been designed and fabricated to shell ground nuts. The manual ground nut shelling machine designed and constructed by Wafula Simon peter an APE student in 2015 had efficiency of 81%, shelling capacity of 100 kg/h with shelling loss of 8.6%. His machine is laborious in terms of operation since the machines requires manual energy to shell the groundnuts, his machine cannot meet commercial demand when large amount of groundnuts are to be shelled, the shelled groundnuts have to be winnowed which is time consuming and slows groundnut processing This research project aimed at improving manually operated groundnut shelling machine designed and constructed by Wafula Simon Peter. To motorized with a blower that separates groundnut seeds from the chaff to eliminate time wasting due to winnowing. The motorised shelling machine meets commercial market demand, easy to operate, less laborious and fast as compared to manual groundnut shelling machine The motorized shelling machine has adjustable shelling blades to reduce on breakage or damage of the groundnut seeds The motorized ground nut shelling machine designed and fabricated consists of components like frame, motor, blower, shelling unit, concave sieve, chaff outlet, seed collecting point. Design and sizing of the various components of the motorized ground nut shelling machine was carried out by analysing forces acting on the components that lead to proper selection of materials. The materials selected are those that withstand the applied forces in order to avoid failure of the components during machine operation. Machine shelling capacity of 66kg/hr, efficiency of 54% and mechanical seed damage of 45% was obtained after testing the prototype. The cost evaluation of the designed and fabricated prototype was carried out. After carrying out economic analysis, the prototype was found to be very viable to the farmer since its ROCE value is positive. The machine is affordable to farmers and can be fabricated from any workshop since it’s made up of readily available materials. Machine operation recommendations are discussed in this report that include changing the sieve depending on the diameter of the grain seed diameter among others. Key areas for future improvements are also discussed at the end of this report that include increasing the size of the hopper for accommodate larger amount of groundnuts during shelling operation