Corn Ear Threshing Performance of Filler-Plate-Covered Threshing Cylinders
Keywords:threshing loss, grain separation intensity, grain damage, feed rate, threshing cylinder design.
The aim of the study was to determine the influence of threshing cylinder filler plates on threshing and grain separation losses, grain separation intensity through concave and grain damage. The comparative corn ear threshing experiments were performed using an open (conventional) threshing cylinder; filler plate I (FP-I) with a shape resembling the standard shape of the cylinder spaces between adjacent rasp bars; filler plate II (FP-II) with a working plane at an angle of 55° to the radius of the cylinder; and filler plate III (FP-III) with a working plane at an angle of 36° to the radius of the cylinder. Feed rates varied from 4 kg s−1 to 12 kg s−1. An increased feed rate resulted in increased the influence of the shape of the spaces between the cylinder rasp bars. Grain separation was found to be most intensive when the threshing cylinder was covered with set FP-III at a 12 kg s−1 feed rate. An increase in feed rate caused grain loss to increase too. The least threshing loss was suffered at a feed rate of 4 kg s−1 when the threshing cylinder was covered with set FP-III. To summarize the grain damage data with respect to the entire threshing unit, grains were found to be damaged least when the threshing cylinder was covered with set FP-III.