Running resistance of scraper conveyors: an investigation based on coal viscoelasticity with experimental validation

Purpose The running resistance of the scraper conveyor is a primary factor leading to severe wear of the intermediate trough and a decrease in transmission efficiency. This paper aims to calculate the running resistance more accurately by establishing an improved mechanical model of the scraper conveyor. Design/methodology/approach Using the discrete element model and Plackett–Burman test, the important factors affecting the running resistance are screened out. According to the viscoelastic contact characteristics of coal bulk material and important factors, combined with Box Behnken design test, the improved dynamic model of scraper conveyor running resistance is established. A test bench of scraper conveyor running resistance is established to compare and analyze the running resistance calculated by the improved dynamic model and the test bench under different working conditions. Findings The results show that under the working conditions of no-load starting, heavy-load starting, upward and downward conveying, the errors of the improved dynamic model are reduced by 69%, 76%, 77% and 47%, respectively, compared with the traditional empirical formulas. Originality/value This study provides a more accurate model and technical suggestions for determining the driving power of the scraper conveyor, designing the wear-saving intermediate groove and determining the preloading force of the scraper chain.