Design, Manufacture and Performance Evaluation of an Effective Dual Operated Groundnut Decorticator with Blower

A manual ( hand operated or bicycle paddle ) groundnut decorticating machine attached with a blower is designed, manufactured and its performance assessed. The main components of the machine were the frame, hopper, neck feed control gate, shelling drum, shaft running on bearings, a pneumatic type mechanism, concave sieve and a blower. The rest are pulley and sprocket, discharge outlet and belt drive. The assembled angle iron parts were welded together whiles the sheet metal parts were riveted to hold in position. Testing of the decorticating machine was assessed at three different moisture contents of groundnut (0, 5.1 and 9.3%) and three different levels of machine shaft speed (10, 20 and 30 rpm) all at an average feed rate of 25kg/hr. The results revealed that the decorticating machine’s optimum performance was at 20 rpm machine shaft speed with groundnut moisture content of 0% (purely dry), machine cracking efficiency and percentage groundnut fully cracked was 71.2% and 85.3% respectively. There was reduction in machine performance at machine speeds of 10 rpm and 30 rpm with 45.1%, and 49.7% machine cracking efficiency respectively for the same feed gate rate openings. This was because at a speed of 10 rpm, the nuts were partially cracked (41.6%) and that of 30 rpm and cracked (39.3%), the quantum of groundnut losses through the blower increased considerably leading to a reduction in the quantity of groundnut collected.