EXPERIMENTAI STUDY ON THE CLEANING PERFORMANCE OF BIONIC SCREEN BASED ON EARTHWORM MOTION CHARACTERISTICS

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.