Ready to wear: proper wear parts maintenance helps keep operations running smoothly

Construction & Demolition Recycling, March-April, 2005 by Jackie Gubeno

For concrete, wood and mixed C&D recyclers handling tough material, it's not a question of if, but when and how often, wear parts must be replaced. And keeping on top of wear part maintenance is one way to keep equipment working efficiently and a recycling operation running smoothly.

Wear parts can account for nearly 20 percent of a recycler's costs, Aaron Benway, sales engineer for CBI Inc., Newton, N.H., says. But that figure can vary greatly, depending on the recycler. You can spend as much as you want, says Devin Davis, marketing coordinator for Morbark Inc., Winn, Mich.

No matter what their resources or needs, recyclers can extend the lives of their wear parts, lower their costs and reduce their headaches.

MATERIAL MATTERS

Replacement is unavoidable no matter what the application, but the kind of material processed plays a roll in determining the lifespan of wear parts. Concrete crushers and wood grinders handle vastly different material streams, and it shows in how hard they are on their wear parts.

"Wood is generally harder to process than concrete because of the high number of variables," says Benway. Different wood types, moisture content and required end-product size make processing wood debris particularly challenging on wear parts, though the actual costs do not necessarily differ all that much, he says.

And within wood grinding applications, there are variances in wear parts costs. For instance, tub grinders tend to incur higher wear costs because they handle rougher material, says Benway.

"Tub grinders have more moving components operating at higher speeds," he says, resulting in higher wear and more parts needed with greater frequency.

Comparatively, horizontal grinders operate at slower speeds and generally have fewer moving parts.

Finally, Benway says that slow-speed shredders generally suffer the least wear because of the reduced rotor speed.

Material makes a difference for concrete crushers, too, says Jeff Hillis, parts sales manager at Eagle Crusher Co. Inc., Galion, Ohio.

"Typically, there's a rather large range (in costs) because of the material," Hillis says. "If it's abrasive, the costs go up." Hillis says he has seen wear parts costs vary anywhere from 3 cents per ton up to 18 cents per ton.

The crushing business deals primarily with three materials--concrete, asphalt and slag--Hillis says, each with a slightly different impact on a machine's wear parts.

"With nickel slag, wear costs are moderately high," he says. "The abrasive factor in concrete varies widely on the aggregate used to make it. If it's made out of say, midwestern limestone, wear costs will be low because it's not as abrasive. But if it's made out of something like sea shell rock, the costs tend to go up."

Asphalt, Hillis says, is also rather abrasive, but using a harder alloy can keep costs low.

Jim Dykes, owner of Dykes Paving, Atlanta, says his shingle grinder bears the brunt of the wear costs at his operation, which recycles concrete, asphalt pavement and asphalt shingles. The company has four types of machines: a cone crusher, an impact crusher, a jaw crusher and the shingle grinder, and each eats up its fair share in wear parts.

Mixed C&D recyclers may have the toughest time of all with some of the most varied and abrasive material, as well as an increased risk of contaminants finding their way into the feedstock.

"This is an extremely harsh environment on equipment," says Dennis Blanchard, general manager of mixed C&D processor Recovermat, Halethorpe, Md. "It's an extremely aggressive material."

MAINTAIN

Keeping on top of wear maintenance is key to maintaining a smooth operation, manufacturers and recyclers say.

At Recovermat, Blanchard says every member of the crew helps with daily preventative maintenance to help squeeze the most life out of wear parts. "The crew is the difference," Blanchard says. "Once you get a really well-trained crew who really knows what they're doing, that's the key."

Gino Edwards, operations manager of wood grinder Environmental Resource Return Corp. (ERRCO), Epping N.H., agrees. "Operators are key; those who know the equipment well," he says.

Edwards says that the bulk of his wear costs at ERRCO comes from hammers and grates, which he replaces fairly regularly every two to three months.

Edwards advises getting on a regular schedule and setting a maintenance timetable to stay on top of things. "After nearly 10 years in the business, you get to know the equipment," he says.

But just because the parts are meant to be replaced doesn't mean you can't try to get the most use possible out of them. Edwards says trying to process the cleanest possible wood debris--removing any metal or dirt--helps ease wear.

Blanchard says the same thing goes for the mixed C&D. He says controlling the feedstock--pulling all the metal from his material and keeping the blend balanced-also squeezes a extra fife out of wear parts.

Hillis also recommends preparing concrete material before crushing. "All manufacturers will have a recommended feed size," says Hillis. "Our crushers will crush anything that fits into them. However, if that material is prepped and sized to our specifications before it goes in, it will help enormously with the wear costs."