Insider information: C&D recyclers offer their advice on selecting and optimizing wear parts for shredders and grinders
Wear parts can represents considerable portion of C&D recyclers’ operating costs. After all, as Carl Busse of concrete recycler Vulcan Materials, Elgin, Ill., says, “We are in the business of wearing out equipment. The outcome is some rock on the other end.” And the more tonnage a company processes (or the more rocks or sticks it produces), the more money it is likely to spend in wear parts.
While the price and the quality of the wear parts figure into a C&D recycler’s choice, they are not the only considerations. Additional services, such as inventory assistance and reverse engineering, are also valuable to C&D recyclers and can give one supplier an edge.
In addition to the help and support they get from wear part suppliers, C&D recyclers themselves can also take a few steps to extend the life of their wear parts and to control their costs to some degree.
MONITORING WEAR. Most C&D recyclers monitor their wear parts costs rather closely, and many agree that their operators’ knowledge can have a significant impact on their longevity.
“It is the knowledge of the people that really makes a difference,” Busse says. “Experience is tough to beat.”
“A poor operator can cost you a lot of extra money,” Dennis Blanchard of Recovermat, Halethorpe, Md., says. Recovermat is a processor of mixed C&D material. “Watch your operators and try to make sure that they are taking good care of the machines,” he suggests.
Gino Edwards of Environmental Resource Return Corp. (ERRCO), Epping, N.H., says experience is the best teacher when it comes to wear parts. ERRCO grinds wood for the New England boiler fuel market, processing roughly 70 tons per hour.
“We’ve been doing this now close to 10 years, so we’ve got a pretty good idea how long it takes for something to wear out and when something should be replaced,” Edwards says. ERRCO replaces the hammers in its crushers every three months, while the impact plates usually need to be replaced every four months he says.
“We do spend a lot of money on wear parts,” Blanchard says, “because this is a hammermill and we change hammers weekly.” Recovermat has used an auto shredder to process C&D material since September of 1996, having processed more than 800,000 tons of material during the period.
Blanchard says that the hammermill’s interior wear parts last for years in his operation. “We just replaced, relined and re-guarded the mill.” He adds that this was the first time some of the linings had been changed in the eight years Recovermat has been operating its shredder.
Busse says that constant maintenance of Vulcan’s processing equipment helps to ensure that the company gets maximum life from its wear parts. He also says that Vulcan tracks its costs very closely. “We’ve got it down to very tight figures,” he says. “We know exactly what we spend on what, when and where. It enables us to do what we do as efficiently as we can.”
Vulcan replaces its horizontal impactor blow bars most frequently, Busse says. “The horizontal impactor has the highest wear as opposed to the test of the equipment,” he says, adding that Vulcan’s cone crusher’s wear parts are replaced least often.
A shingle grinder located in the Midwest says that 25 percent of his costs can be attributed to wear parts. “Shingles are very abrasive and very tough to grind. It is a high wear, high maintenance process,” he says.
He asks his operators to be very observant in order to avoid contaminants when loading the shingles into the grinder. “He needs to make sure that there is the proper amount of water going in for dust and for wear. When we get the proper amount of water to control the dust, it also helps to slow up the wear some,” the shingle recycler says.
In addition to having quality operators and monitoring the in-feed material for unshreddables, recyclers can also extend the longevity of their wear parts through hard facing and rotating some wear parts.
EXTENDING LIFE. The shingle recycler rotates the bits in his grinder in order to extend the life of his wear parts and to keep replacement costs down. “We rotate some of them that are not quite worn to the outside and put new ones in the main course,” he says. “But sometimes that gets to be nonproductive,” he says, adding that with the time restraints of some jobs, it makes less sense to rotate the bits. “Out of a given tip in the real impact zone, I can see as much as two eight-hour days of processing,” the shingle recycler says.
The bits the shingle recycler uses are cast of a forged bit body made from AR 400 steel with hard carbides soldered into their heads, he says, while other wear parts may get a carbide-impregnated overlay. “It gives them a really rough, abrasive finish,” he says of the overlay. Additionally, the recycler uses a quarter-inch Trimay overlay on his screens, which are made out of A 36 steel.
Before adding the Trimay overlay to his screens, the shingle recycler was able to process 2,500 tons before the screens needed to be replaced. Now, he says he gets anywhere from 4,500 to 6,000 tons processed before the screens need to be replaced.
When the shingle recycler first purchased his grinding equipment, he says it produced 40 tons per hour of 3/8-inch minus shingles. By designing his own bits, which he has wear parts manufacturers make for him, the shingle recycler now sees much higher processing tonnages.
“I can consistently run 70 to 80 tons an hour,” he says. “Under the right conditions, I have ground over 100 tons an hour,” the recycler adds.
Busse says Vulcan uses a traditional high-chrome alloy for its wear parts. While titanium and ceramic wear parts are available, Vulcan prefers “sticking to what we know absolutely works,” Busse says.
Alloy wear parts are known for their abrasion resistance, while manganese wear parts are known for their impact resistance, one source notes.
Recovermat uses manganese wear parts in its shredder. “We actually flip a set of hammers mid-week and change them at the end of the week, most of the time,” Blanchard adds.
“With this type of operation, we’ve found that manganese is the only thing that really works well,” Blanchard says. “If you keep it work hardened, it lasts longer.” Therefore, the more impact manganese wear parts receive, the more life you will see out of them, he notes.
“We have tried some other materials, some alloy wear parts and hammers. We’ve not had any success with anything. We’ve tried building them up with welds and all kinds of things, and it’s just not cost effective,” he says.
Like Blanchard and Recovermat, many C&D recyclers will test wear parts from different manufacturers prior to settling on a supplier.
The shingle recycler, for instance, thinks experimentation is important. “If I don’t keep up with the new thoughts and the latest products, I am going to get caught in the pits and I am going to get behind,” he says.
The shingle recycler’s first consideration when purchasing wear parts is quality. “If they don’t do quality work, then my parts wear out too quickly,” he says. “Inventory, the service aspect, shipping times and being able to have my designs produced are important, but the quality [of the wear part] really stands high on my list. I am willing to pay more,” he says. “I am not one of those guys who looks for the cheapest product, because the cheapest product doesn’t always win with me.”
SUPPLYING MORE THAN PARTS.
While many C&D recyclers keep at least one complete set of wear parts on hand in case of emergencies, many also find value in inventory assistance from the manufacturer.
“We always make sure we have an extra set of hammers and an extra set of wear parts in stock,” Edwards says.
“I’ve always got parts on hand,” the shingle recycler says. “But I expect [suppliers] to keep parts for me.”
Vulcan inventories a collection of wear parts in a few of its larger facilities, which then service some of the company’s smaller facilities. “Some facilities only come to the larger facility if they can’t get something procured right away,” Busse says.
Waiting for a wear parts supplier to come through with a needed part is not an option for any recycler. While the quality of the part may get them the initial order, if a supplier fails to inventory a sufficient supply of wear parts and causes a customer an extended period of down time, that recycler may think rethink its relationship with that supplier.
RELATED ARTICLE: Value-added services.
Processors of C&D materials look not only for reliable, quality parts, but also for additional services, such as inventory management and engineering services. Just as the following suppliers of wear parts to scrap metal recyclers have realized, these services can help wear parts suppliers to distinguish themselves within the market.
Art Borin of Amsco Wear Products Inc., Goshen, N.Y., says Amsco helps its Customers with inventory management of by modifying equipment designs.
Metso Lindemann of Cedar Rapids, Iowa, offers a tiered pricing structure. Metso’s Denny Jennerjohn explains: “We have one tier for parts that are inventoried for people who like instant service and availability. We offer a lower pricing structure for people who prefer to plan ahead and order a full container load and have it shipped directly to their yards.”
Kevin Toft, who is based in Riverside Engineering’s Moline, Ill., office, says, “We’re not just supplying wear parts; we are supplying fabrication work, engineering services and we can actually purchase scrap back to use in our foundry.”
Greg Stegmaier of Columbia Steel Casting Co. Inc., Portland, Ore., says wear part manufacturers can optimize equipment performance. “This is achieved with quality parts, knowledgeable service, design alternatives and on-hand inventory or short lead times.”
The author is associate editor of Construction & Demolition Recycling and can be contacted via e-mail at firstname.lastname@example.org.
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