اثرسرعت كوبنده ،رطوبت واندازه غلاف نخود بر درصد جداسازي دانه و درصد دانه هاي شكسته در يك كوبنده انگشتي دار

Effect of Impact Velocity, Moisture Content, and Pod Size on Percentage of Damaged Grains and Threshed Pods in a Finger Type Combine Thresher

In this research, the effect of impact velocity, moisture content, and pod size, were studied on percentage of damaged grains and percentage of threshed pods by using a manufactured finger type combine thresher. All tests were conducted on two dryland varieties of chick pea as well as an irrigated one. It was found that the variety of chick pea had no significant effect on percentage of damaged grains and percentage of threshed pods. Impact velocity and moisture content had a significant effect on percentage of damaged grains as well as on threshed pods. The most effect was observed to be related to velocity and the least to pod size. With increasing the impact velocity from 6.3 to 12 mis, the percentage of damaged grains and threshed pods were increased from zero to 7% and from 42 to 85%, respectively. With increase in the moisture content of the pods, the percentage of damaged grains and threshed pods were decreased significantly, while with increase in the pod size, the percentage of damaged grain as well as percentage of threshed pods were increased significantly. Based on these results, the best condition for harvesting this crop would be recommended at a moisture content of between 12% to 18% while an impact velocity of below 9.5 m/s for threshing mechanism.