PM—Power and Machinery: Effect of Type of Drum, Drum Speed and Feed Rate on Sunflower Threshing

A study was conducted to develop a threshing unit for a sunflower thresher. The performance was evaluated in terms of output capacity, threshing efficiency, grain damage, grain losses, grain and material other than grain (MOG) separation, power requirement and specific energy consumption against different drum types, drum speeds and feed rates. The sunflower threshing capacity of a rasp bar drum was higher than peg tooth type, both with open and closed threshing drums. The threshing efficiency was found to be higher than 99%. Visible grain damage increased with an increase in threshing drum speed and feed rate for each threshing drum. The minimum specific energy consumption could be achieved with the rasp bar drum at all speeds and feed rates. The rasp bar drum showed reductions in the proportions of MOG passing through the concave compared to the both peg tooth types, i.e. with open threshing drum and closed threshing drum. The total grain separated by the rasp bar drum was higher than 99%. At 3000 kg[head] h−1 feed rate and 750 min−1 drum speed, rasp bar drum gave higher output capacity, threshing efficiency, lower grain damage and specific energy consumption.