IM 2018 February 18 | Page 53

CONVEYORS Conveying the message John Chadwick examines conveyor transfer points and their design, new systems and advances in conveyor components, including belts et us begin with a maintenance matter covered before in IM but very well worth repeating as it is so important. Mark Baller, Managing Director of transfer chute experts Weba Chute Systems believes that transfer points should be accorded the same importance as other minerals processing machinery. In particular, the effect of the chute’s performance on the life of conveyor belts – which can account for up to 60% of the capital cost of a bulk materials handling plant – deserves attention. “The cost of replacing a conveyor belt – not to mention the downtime associated with belt maintenance and replacement – makes it worth looking more closely at any measures that will extend the conveyor’s life,” says Baller. “Typically, conveyors – like feeders, crushers, hoppers and screens – are selected to match certain operational requirements; however, there is little emphasis on the design of the chutes transferring materials between elements.” This is a mistake, he argues, as chutes are essential elements in a bulk solids handling plant, and are also subject to operational characteristics and physical constraints. “Among the most common problems on transfer chutes are spillage, blockages and high levels of wear on the receiving belt due to major differences between the material velocity and the belt velocity,” he says. “There is also misalignment of the receiving conveyor belt – which is caused by uneven loading from the transfer chute.” L Key to solving these challenges is good design, he emphasises. While conventional chute design often allows the uncontrolled discharge of bulk materials, Baller considers that a holistic design is necessary – focusing not only on the entry and exit points, but also contr