Study on Grain Distribution in a Cross-flow Grain Separation Chamber Based on the Discrete Element Method

Abstract

<abstract> <bold>Abstract.</bold> Grain separation chamber is one key component of combine harvester, which determines the quality of grain product. Cleaning and sorting of grains by airflow are in accordance with the differences among the composition’s aerodynamics of grains. To improve the separation performance, a cross-flow grain separation device was designed by employing the cross flow blower. The grain distribution in the separation chamber was investigated using gas-solid two-phase flow model based on the discrete element method (DEM) and by experiment at the same scale. The gas-solid two-phase flow model was established by Fluent-EDEM coupling method where the gas flow field in the chamber was meshed into continuous grids in Fluent while the grain components were modeled in EDEM. The resulting model was solved to obtain the grain distribution in the chamber. The model was validated against experimental results which were obtained in a test rig for paddy rice separation. Paddy rice movement in the experiments was tracked using a high speed video camera system (HSVCS). The results could provide theoretical basis to further increase the performance of the grain separation chamber.