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Conveyor transport at a modern coal mine is the main link that determines the overall performance of the enterprise. For safe operation of belt conveyors, it is important to ensure that shift output per face doesn’t produce average and maximum minute material flows, which exceed strength margin of the belt, power margin of the drive, and receiving capacity. Such situation, as a rule, may arise due to the strive of workers to compensate for underproduction caused by long downtimes of a face for any reason. In the paper, a method is proposed that enables determining the maximum shift output per face. According to the technique described in the “Basic Provisions for Designing Underground Transport of New and Existing Coal Mines,” the average minute material flow, which determines the operational load on a belt conveyor, depends on the material feed time factor. Accepting the assumption that a coal shearer works the entire shift in a face, the limiting value of the material feed time factor is equal to 1. To determine the actual value of this factor, it is proposed to determine the face operating (production) time using actual planogram. The shift time is spent for preparatory and finishing operations, the face equipment and conveyor line troubleshooting and failure recovery, auxiliary service operations and, finally, operational and organizational downtimes. On the actual planogram, these time intervals are displayed by straight-line portions. Thus, the shift time minus downtime for any reason, represents the face production time. The ratio of these values represents the operation factor. Applying the operation factor allows to determine the maximum limiting face production, not only taking into account the volume of coal mined per cycle, but also based on coal cuttability and technical specifications of the face equipment. This enables us to determine the face production load that ensures safe operation of the belt conveyor. |
