Bulk material transportation requirements have continued to press the belt conveyor industry to carry higher tonnages over longer distances and more diverse routes. In order keep up, significant technology advances have been required in the field of system design, analysis and numerical simulation. The application of traditional components in non-traditional applications requiring horizontal curves and intermediate drives have changed and expanded belt conveyor possibilities. Examples of complex conveying applications along with the numerical tools required to insure reliability and availability will be reviewed.

High-capacity and high-angle pressure belt conveyors which come into use in open pit mines in Russia and in the post-Soviet space, as well as acknowledgment of their economic efficiency made large mineral mining companies interested in installation of such equipment. The related research and empirical data grow in number. However, conveyors currently operated in Russia and in the CIS countries are manufactured abroad. Both domestic and foreign technical literature lacks a commonly accepted design policy of the conveyors. Furthermore, most foreign-manufacture high-angle pressure belt conveyors have small angles and lengths. In the meanwhile, open pit mines in Russia need long high-capacity and high-angle conveyors. Many aspects of justification of high-angel conveyor parameters are sufficiently elucidated in technical literature. The estimate of the hold-down and its dependence on the angle and length of a conveyor is yet deficiently studied. The value of the hold-down has a direct influence on the conveyor characteristics, including resistance to motion and engine power requirements. Accordingly, this article analyzes the influence exerted by the angle and length of a conveyor on the hold-down. The stress state of the load on the belt of the high-angle conveyor is analyzed, and the required holddown is evaluated with respect to the conveyor capacity, angle and length. It is known that hold-down governs loading of the load-carrying branch, which affects its service life. The analysis shows that 30 % of down-time of high-angle conveyors in the world is caused by failures of the load-carrying branch. The relations are proposed for determining the required linear hold-down versus the length of a conveyor to ensure sliding of cargo layers relative to each other and relative to the belt along the longitudinal axis of the conveyor. The recommendations on hold-down distribution along the conveyor to slacken the hold-down influence on the resistance to motion and on the engine power are proposed.

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