Aggregates Manager Digital Magazine
Issue link: https://read.dmtmag.com/i/85648
EQUIPMENT MANAGEMENT 1 Feed the machine is the feed system. Whether it's a feeder with an integrated grizzly or a feeder with an independent prescreen, how the machine is fed contributes to wear. One of the major points to remember when setting up and maintaining a ma- chine is that the machine must be level. If the machine is unlevel left to right, it will cause increased wear on all components from the feeder to the screens, crushing chambers, and conveyor belts. In addi- tion, it reduces production and screening efficiency, as it is not effectively using the whole area of the machine. Having the ma- chine sit high at the discharge end will have the effect of feeding the material uphill in the feeder, reducing its efficiency, and thus reducing production. beast properly The first area of wear on any 2 Another area for consideration is the equipment with which the machine is fed. If fed with a loader, the operator can't see in the bucket and has no control over the feed size. With an excavator, the operator can see what's inside and has more control over the feed into the hopper. Not feeding as much material all at once and control- ling the size of the feed reduces wear in the impact zones of the feed hopper and elimi- nates material blockages due to feed size being too large to enter the chamber. The standard integrated feeder is a grizzly section that is integrated into a vi- brating feeder, so the feeder and the griz- zly move at the same time. It's a set of ta- pered fingers that allows material less than the size of the opening of the grizzly to drop through, bypassing the crusher. This reduces wear on the crusher, as material that does not need to be crushed never enters. That material is bypassed or sent to a side conveyor, but is not screened to a classified saleable product. These grizzly fingers must be rebuilt and hardfaced to Grizzlies and prescreens This woven wire mesh has been damaged by too large material passing over. maintain the sizing of material that is be- ing removed. The action of an independent prescreen is completely independent of the feeder. It also has the grizzly fingers at the top, or punch plate, but underneath, material falling through goes through a woven wire mesh sized to any product the operator wants. Material not passing the mesh is by- passed around the crusher and discharged with the crushed product, thus reducing wear inside the crushing chamber. In addition to maintenance on the griz- zly fingers, the screen mesh must be in- spected for worn, broken, or bent wires and the seating face and tensioning devices in- spected for the mesh. To obtain a screened product, it is critical to maintain the mesh so not to allow material to fall outside of the required specification. Thus, with an independent prescreen, the operator avoids unnecessary wear in- side the crusher and boosts production of material that actually needs to be crushed. AGGREGATES MANAGER May 2012 35 Easy does it: Material dropped from a height deforms and wears hopper walls.