Analysis of moving averages of BWEs actual capacity

Abstract

Analysis of productivity data from different lignite mines leads to the conclusion that theoretical BWE capacity is utilized only in a small percentage. Therefore, it is possible to achieve a substantial reduction of energy consumption by optimal dimensioning of BWEs and belt conveyor parameters to actual loads generated during the cyclical excavation of subsequent slices, terraces, blocks, and benches. Based on the analysis of BWEs efficiency and time series of their actual volume capacities in a Polish opencast lignite mine, it is proposed to apply the Extreme Value Theory (EVT) for dimensioning belt width and for selecting required power of conveyor drives. The asymptotic decrease of high order percentiles of actual capacity averages with the increase of loading time (the length of receiving conveyors) shows that there is a big potential for energy savings.