Prediction of multi-area transportation state in thecentral trough of scraper conveyor

Scraper conveyor is a large-scale conveying equipment for fully-mechanized coal mining face. The central trough is used as the load-bearing component of the scraper conveyor. Its working reliability and service life directly affect the transportation efficiency of underground coal. However, at present, the existing test methods are difficult to accurately predict the transport status and service life of central trough. In order to in-depth study the coal transport characteristics of the coal bulk materialin the central trough, the wear characteristics of the bulk materials and its basic principles, the coupling model of bulk coal and central trough was established by using discrete element method in this study. The corrected model parameters were used to predict the transport state of the central trough, the wear of the central plate, the force characteristics of the bulk materials and the central plate, including the kinematics of the bulk coal under different full loads, the wear of plate in the middle groove under different loads and different percentage of gangue, and the force of of the plate in the middle groove under different areas and different full load conditions. The results show that the distribution of bulk coal on the scraper conveyor has the“Brazil fruit effect”, and the accumulation quality of bulk coal in different areas of the central trough is quite different, and the larger the carrying capacity is, the more obvious the“Brazil fruit effect”; the wear of middle plate is mainly concentrated at the lower part of double-row scraper chain, and the wear amount under this area is much larger than that in the non-chain distribution area; the wear amount of the middle trough increases with the increase of load, and the wear amount of the central trough under 140% load was about 3.49 times of that under 60% load; the wear amount of the central trough increases with the increase of the gangue content, and the wear of the bulk coal with 25% gangue content on the central trough is about 4.11 times that of without gangue; the average normal load of the middle plate under the scraper chain is the largest; the greater the load, the greater the average normal load of the plate in the middle groove. This study can provide a theoretical basis for the corresponding wear-resistant strengthening treatment in different areas of central trough, and can extend the service life of the central trough to the greatest extent.