Effects of Different Concave, Drum Speed and Feedinging Rate on Soybean Threshing

摘要

This work reports to determine the soybean threshing efficiency and power requirement effects of different convave types. A special threshing machine and four concavs made of different materials were used for the trials. The threshing machine has spike-tooth drum, driven by from a 4 kW electricity motor through belt-pulley system. The soybean variet SA-88 is used for the trials. Threshing trails were conducted four different concave types (PVC, rubber, chromium, and steel plate), three different feedinging rates (360 kg/h, 720 kg/h, and 1080 kg/h) and five different drum speeds (7.95 m/s, 9.10 m/s, 10.54 m/s, 12.16m/s, 14.66 m/s), thus power requirement, specific power consumption and threshing efficiency were determined. The results have showed that the power consumption increases with increasing feedinging rate and drum peripherial speed. The lowest power requirement of 0.212 kW was obtained at a feedinging rate of 360 kg/h, drum peripherial speed of 7.95 m/s, and the PVC concave type. The highest, 1.945 kW, was obtained at the feedinging rate of 1080 kg/h, drum peripherial speed of 14.66 m/s with rubber concave type. Threshing efficiency decreases with increasing feedinging rate whereas increasing drum peripherial velocity significantly improves the threshing efficiency. The highest threshing efficiency of 93.85% was achieved with chromium type concave followed by the PVC, the steel plate, and the rubber.