Aggregates Manager Digital Magazine
Issue link: http://read.dmtmag.com/i/214806
TIONSConveying ILLUSTRATED Clean 2 For quality's sake 3 For productivity's sake Conveyor housekeeping issues can also affect a facility's product quality. Fugitive dust from conveyors will coat material in stockpiles, creating problems with fines on clean products. Spillage of oversize material can be dragged into smaller-size material, and carryback can also result in excessive pockets of fines falling into stockpiles, where they create fines pockets in the sized material. The latter two issues create problems with gradation. Obviously, the manual labor involved in cleaning conveyor spillage and fugitive dust will affect an operation's productivity and efficiency, but the spilled material is often valuable product, which belongs in a stockpile. Conveyor components and add-ons, such as belt cleaners, impact idlers, and transfer seal equipment, can help to reduce spillage and dust issues, while also helping to ensure products ultimately end up in the correct stockpiles. 5 6 Correct and support the belts For conveyors to do their jobs as designed, the belt must be specified for the correct pounds per inch of width, trough angle, and aspect ratio (thickness of top cover to bottom cover), as well as the minimum bend radius. If the wrong belt is specified, it will not track correctly, it will cause spillage, and it will wear quickly. Support in the load zone, via impact idlers, impact beds, or slider beds, will also reduce spillage and carryback. OUR EXPERTS Larry Goldbeck is manager of conveyor technology for Martin Engineering, based in Neponset, Ill. He has been with Martin Engineering since 1981. Prior to joining Martin, Goldbeck spent 12 years in solids-handling industries. He holds four patents on components to help belt conveyors operate more cleanly, safely, and productively. Goldbeck is primary author on all four editions of the "Foundations" books about belt conveyors. Seal transfer points Entry seals and exit seals, along with side rubbers, will keep material where it belongs — on the belt. Chutes and venturis can work at transfer points to respectively suppress dust (with or without water), or collect dust using a vacuum system. There is a higher up-front cost for such add-on components, but their safety, labor-saving, and belt-life-saving benefits will also save producers money down the road. Dana Boyd is a vice president at Cloverdale, Ind.-based North American Limestone Corp. (NALC). He has 25 years of experience in the mining industry, having held positions in operations, safety, environmental, quality, and sales/ marketing. He has managed 15 different operations during his career, from sand and gravel to crushed stone, including surface and underground mines. December 2013