Complex granular flows of sticky-wet material on flip-flow screens: Calibration of discrete element simulations

Abstract

Discrete element method (DEM) is an effective approach for studying the screening process of flip-flow screens. However, there have been few studies focusing on the thick layer of sticky-wet particles on flip-flow screens. To achieve accurate simulations of the thick layer of sticky-wet particles on a flip-flow screen, firstly, the movement law of particle flow was studied, and a multi-regime combination calibration method based on characteristics of particle flow regimes was proposed. Based on the Plackett-Burman experiment, the curse of dimensionality caused by multi-state and multi-contact parameters was overcome. Subsequently, the lifting cylinder, rotating drum, and trampoline tests were carried out to obtain macroscopic reference values under various granular flow regimes. The calibration results were then determined using the response surface method and climbing algorithm. Finally, the calibration results were tested at both macroscopic and mesoscopic scales and compared with a commonly used calibration method. The results demonstrate that the calibration method, which considers the multi-state characteristics, improves simulation accuracy by 2%–10% and reduces the simulation error to less than 10%, thus meeting the requirements for engineering optimization of flip-flow screens.