Performance evaluation of a motorized legume threshing machine

Grain threshing and separation are important post-harvest unit processes because it reduces excessive wastage and adds values to farm produces amongst other benefits, thus the performance parameters of the legume threshing machine was determined experimentally. The effect of static coefficient of friction was on the Threshing Efficiency (TE), Separation Efficiency (SE), Grain damage and Machine throughput were determined. The study was carried out using a randomized design of three feed rates (FR): 10g/s, 15g/s and 20g/s, four surfaces (S) mild steel (MS), plywood (PLD), carpet (CPT) and Rug (RG) using cowpea (Vigna unguiculata) IT84S-2242 and soybean (Glycine max L) 1448-2E variety. The cleaning efficiency obtained for soybean samples was 96%, while threshing efficiency was 99%. For cowpea threshing and cleaning efficiencies were 97.44 and 97.16%, from carpet surface. Statistical analysis using (ANOVA) showed that impurity level and feed rate affected cleaning efficiency at both 1 and 5% significance, type of surface affected threshing percentage and broken seeds at 5% significance. Using carpet surface resulted in the highest cleaning efficiency, threshing efficiency, low grain damage and grain losses at 100 g batch weight. In conclusion, coefficient of friction could be utilized to increase separation efficiency of thresher, this would aid the development of appropriate technologies for legumes processing