Research on screening performance of double layer vibrating screen for soybean harvester based on discrete element method

Abstract

In order to improve the screening effect of grain combine harvester, it is necessary to study the influence of different screening parameters on screening performance.In this paper, discrete element method was used to simulate the screening process of soybean and short stems by selecting different screening parameters, and dynamic screening efficiency and the number of short stems under screening were introduced as evaluation criteria.The results show that under certain other conditions, the vibration frequency, amplitude and direction angle have significant influence on the screening performance, while the inclination angle of the upper screen has little influence on the screening performance. With the increase of vibration frequency, amplitude and direction angle, screening efficiency increased first and then decreased, while the number of short stalks under screening increased first and then decreased. Considering the screening efficiency and the number of short stalks under the screening, it is concluded that the screening performance is better when the amplitude is 25 mm, the vibration frequency is 4 Hz, the vibration direction angle is 25 degrees and the upper screening angle is 3 degrees. The simulation results are verified by field experiments, and the simulation results meet the requirements of field experiments.