Authors

Abstract

As the feeding mass of harvester continues to be increased, the accumulation of the maize mixture on the screen more serious, leading to a decrease in screening efficiency of the cleaning screen. The maize mixture on the screen was quickly transported backward through a bionic screen based on the motion characteristics of earthworms to reduce accumulation. However, the impact of the main operating parameters of this bionic screen on the cleaning performance was not yet clear. Therefore, the main operating parameters that affect the loss percentage and impurity percentage of maize grain in the cleaning device of bionic screen were simulated using CFD-DEM. Analysis of variance, regression and response surface were carried out on the test data, and the optimal parameter combination was obtained through parameter optimization: the concave depth of the screen surface was 25 mm, the installation angle of the screen surface was –5.5°, and the airflow velocity at the inlet of the cleaning device was 12.3 m/s. At this time, the lost percentage of maize grain was 1.56%, and the impurity percentage of maize grain was 1.85%, which met the requirements of national standards. The experiment provides reference and basis for the follow-up exploration of the screening mechanism of bionic screen.

Abstract in Chinese

随着联合收获机喂入量越来越大，玉米脱出物在筛上的堆积越发严重导致清选筛筛分效率降低。基于蚯蚓运动特征的仿生筛能够将筛上玉米脱出物快速向后运移从而减少堆积。但是此仿生筛主要作业参数对清选性能的影响尚不明确，为此采用CFD-DEM耦合方法对影响仿生筛清选装置玉米籽粒损失率和含杂率的主要作业参数进行了仿真试验。对试验数据进行方差分析、回归分析和响应面分析，并进行参数优化得到较优的参数组合为：筛面下凹深度25 mm，筛面安装倾角–5.5°，入口气流速度12.3 m/s，此时，玉米籽粒损失率为1.56%，籽粒含杂率为1.85%，清选性能满足相关标椎要求。试验为后续仿生筛筛分机理的探究提供参考和依据。