Research on impact characteristics of middle trough of scraper conveyor

In order to research impact characteristics of coal materials, scraper and scraper chain on middle trough of scraper conveyor, normal impact load and impact energy during process of coal materials impacting on middle trough were theoretically analyzed firstly based on Hertz contact theory. Then impact process of coal materials on middle trough under mining condition was simulated by use of EDEM simulation software, and curves of normal impact loads on middle trough under different chain speeds and different mining heights were obtained as well as impact force distribution on mid-plate of middle trough. Finally, impact loads of scraper and scraper chain on the mid-plate were tested in the field under no-load condition. The research results show that under different chain speeds and mining heights, normal impact loads of coal materials on middle trough increase rapidly at first, then decrease to a certain range of fluctuation, which increase with the increase of chain speed or mining height. Impact force of coal materials on the mid-plate mainly concentrates in two chain parts. Impact loads of scraper and scraper chain on the mid-plate show periodical step change, and impact loads at mining side chain, goaf side chain and non-chain decrease in turn.