Tarpspragilių dangalų įtaka kukuruzų grūdų separacijai ir sužalojimui

Abstract

When threshing corn ears, spaces between adjacent rasp bars are covered in order to prevent ears from entering into the cylinder. However research on the effect of filler plates between adjacent rasp bars on grain damage and separation are still rare. The aim of this research was to determine the effect of filler plates between adjacent rasp bars of threshing cylinder on corn grain damage and separation through the concave. The experimental threshing unit was comprised of the corn ears belt-feeder with the length of 10 m and width of 1.2 m, and the tangential threshing cylinder with 8 rasp bars with the diameter of 0,6 m and width of 1.2 m, which was enveloped by the grate-bar type concave at the angle of 146°. The part of the grain-chaff separated through individual sections of the concave were collected in tanks for collecting grains that were weighed using electronic weighing scale each 0.3 s. This way, in progress of threshing process, the rate of threshed corn grain separation, expressed as k (kg s"1), through the concave grate-bar was determined at its different sections. During the entire research, corn ears were evenly spread on 7 m long belt-feeder at its entire width. First, corn threshing experiment was performed without filler plates between adjacent rasp bars. For the purpose of comparative trials, spaces between adjacent rasp bars were covered by stainless-steel plates with thickness of 1.5 mm, and with the mass of 2.54 kg each. Covering spaces between the adjacent rasp bars with filler plates has a positive effect on grain damage during threshing (reduces percentage of damaged grain from 3.49% to 2.77%) and grain separation through the concave (increases grain separation intensity through concave by 0.35 kg-s"1). Further research is necessary to optimize surface form of the filler plates used to cover spaces between adjacent rasp bars.