The impact of an uneven loading of a belt conveyor on the loading of drive motors and energy consumption in transportation

The object of the present study is the process of transporting the mined bulk by a belt conveyor during intensive coal mining. The subject of the study is the impact of uneven load flow patterns on the energy parameters of transportation and the resource of the belt conveyor during heavy mining of coal. The aim of the study is to assess the impact of the weight of the load that is transported by a conveyor belt on the drive motors loading and energy consumption during intensive coal mining. The research is performed through a statistical analysis of experimental results obtained by the Dongiprovuglemach institute (Ukraine) regarding the load flow and the capacity of the belt conveyor 2LU120V used by the mine Dovzhanska-Capital (Sverdlovsk, Ukraine). The capacities of drive motors were considered through a regression analysis. A correlational and spectral analysis was applied to consider the load flow, the load weight, and the capacities of the drive motors. The study has specified the estimated drag coefficient in the movement of the conveyor belt under conditions of intensive mining of coal. Specific energy consumption for transporting the mined bulk by the conveyor was estimated regarding the loading of the belt. The work was done to assess the effect of the size and type of the load flow and the load weight on energy consumption and the resource of the conveyor and to justify a further increase of the technical level of belt conveyors. The results show substantial irregularities in the load flow and the transported load weight, their impact on the amount and type of an uneven loading of the drive motors, and specific energy consumption for transportation and the conveyor resource. The study has shown that if the loading is small a bigger load is imposed on the drive motor that is located in the place of the belt running off the drive; if the load in big, a bigger load is imposed on the drive motor that is located in the place of the belt running onto the drive. The main dispersion of the load flow occurs at low frequencies corresponding to the duration of the technological cycle of extracting and transporting coal. When the modes of the conveyor operation are close to the maximum load of the belt, energy is least of all consumed for transporting the load. If the loading is reduced, there is a hyperbolic increase in specific energy consumption for transportation. The drag coefficient of the conveyor belt movement, obtained by the experiment data on the capacity value of the idly running conveyor, is significantly higher than the value that is suggested by the method of a technological calculation of the process. This factor should be taken into account while determining the capacity of a drive and calculating the traction of the machine. The results can be used for creating belt conveyors within mining systems of an improved technical level for highly efficient intensive coal mining.