Effect of guide strips on the distribution of threshed outputs and cleaning losses for a tangential-longitudinal flow rice combine harvester

The transverse distribution of the threshed material in a typical tangential-longitudinal flow combine harvester is uneven and this is likely to cause local accumulation of materials on the cleaning screen. Cleaning performance and efficiency reducing problems are easily caused. In this study, discrete element simulation was applied. The distribution position of the guide strips on the threshed outputs distribution was analysed. The threshing outputs under threshing cylinder were divided into seven sections, with the total making up the threshing ration. Using the standard deviation of threshing ratio as an evaluation criterion, the optimal structural parameters of the distribution devices were obtained. In order to verify parameter accuracy, field tests were carried out to monitor the threshed outputs distribution along the transverse direction on the cleaning screen. The cleaning loss rate was analysed statistically. It was concluded that the cleaning performance of tangential-longitudinal-flow combine harvester was increased by the automatic distributing system; including threshed outputs, lateral distribution evenness along cleaning shoe was improved and local accumulation was reduced. The adaptive system decreased the criterion used for evaluation by 42%. Under a 1 m s(-1) working condition, cleaning loss decreased by 71.67%, and under a 1.5 m s(-1) working condition, the cleaning loss decreased by 50%. (C) 2020 IAgrE. Published by Elsevier Ltd. All rights reserved.