Inclined conveyors have a backstop arrangement that stops it from running backwards under load, which is important in coal mines as conveyors can extend to vast lengths. This is crucial for preventing tonnes of rock and coal acceleration backwards and offloading at the end of the conveyor resulting in potential high loss of production time and causing extensive damage.
Bearing this in mind, a coal mine, based in Pennsylvania, researched into a new inclined coal conveyor, in order to potentially gain larger returns for reliability, productivity and efficiency. Knowing the conveyor had the capability to run backwards in a controlled manner, the Pennsylvanian engineers believe it would have significant advantages when clearing blockages and undertaking maintenance.
The engineers searched for an appropriate clutch or other mechanical mechanism that would fill the projects needs. Stieber Clutch’s RDBK high-speed backstop was chosen to meet the requirements of the conveyor.
The RDBK is a centrifugally operated, lift-off sprag, high-speed backstop, equipped with integral torque limiter – performed through a multi-disc brake and limits the backstop’s transmissible torque to a value that is factory set, in agreement with user specification. It is often specified on multi-drive systems, such as large inclined conveyors, where two or more backstops share the reverse load.
The backstop is designed in order to be fully bearing-supported. It rotates backwards under overload so it can perform several reverse rotations as needed – within energy dissipation limits - to fully unload the conveyor before maintenance work commences.
Mine operators believe, with the use of the RDBK, a conveyor will be held in place regardless of an event failing. Also offloading the conveyor is a less complicated process, which permits maintenance work to be completed quickly and reduces downtime.
Edited from press release by Harleigh Hobbs
Read the article online at: https://www.worldcoal.com/handling/21052015/a-solution-for-controlled-back-running-of-inclined-conveyors-2314/