Development a cleaner for thresher of sunflower grain and optimization with RSM

Abstract

Nutty grain sunflower is threshed in high moisture content (harvesting moisture), contains various impurities that need to be removed before further processing. Cleaning unit include of oscillation screens using kinematic equation and physical properties of grains was designed, constructed and evaluated for separating impurities of threshing unit. RSM modeling method utilized for designing experiment and optimization of variable. The effects of oscillating frequency (7.6, 5.6, 3.6 Hz), slope (0.12, 0.07, 0.02) and amplitude oscillating (25, 17.5, 10 mm) of screens were studied. The results showed that the models were statistically significant at the 95% confidence level. It was observed that the amplitude oscillation on cleaning efficiency% and screen slope on grain loss% had the greatest effect followed by other factors. Maximum amount of cleaning efficiency observed 93.98% at frequency 7.6 Hz, slope 0.12 and amplitude oscillation 25 mm. Also, minimum amount of grain loss reported 1.69% at frequency 5.6 Hz, slope 0.07 and amplitude oscillation 25 mm. Cleaning efficiency% tended to increase with decreasing oscillations frequency while grain loss% increased then reduced insignificantly. With increasing in screen slope, cleaning efficiency% increased and grain loss% slightly decreased, then increased. Increasing the oscillation amplitude caused to the cleaning efficiency% reduced and grain loss% increased then decreased insignificantly. The optimum conditions for maximizing cleaning efficiency% and minimizing grain loss% were determined at oscillation frequency of 7.5 Hz, slope screen of 0.104 and oscillation amplitude of 25 mm.