A Step Ahead

With materials costs, fuel prices and insurance rates higher than ever, the importance of cost control has grown to match. In today’s economy, business owners are constantly on the lookout for ways to save. Since capital equipment represents such a significant investment, it is vitally important for recyclers to get the most out of the equipment they have.

Construction and demolition recycling operations demand a lot from their equipment—the material is bulky, widely variable and often full of challenging contaminants, which subjects processing equipment to a great deal of wear and tear.

Horizontal grinders deal with some of the toughest material in the market—wood from the mixed C&D stream must be carefully sorted to avoid metal contaminants getting into the final product. The application is demanding, but with some forethought, regular maintenance and careful planning, recyclers can control wear costs and keep their machines running at optimum levels.

Common wear parts on horizontal grinders include teeth, hammers, inserts, screens, belts and filters. These components are built to be replaced, but that doesn’t mean an operator should ignore them until it comes time to change them. Careful monitoring and management of wear parts can extend their useful lives and the life of the machine as a whole.

First, it’s important to make sure infeed material is as clean as possible. Not taking the time to do so is one of the biggest mistakes operators make when it comes to running horizontal grinders. "Dirt accelerates wear on inserts, hammers and grates," says Michael Stanton, a salesman for Morbark Inc., Winn, Mich., which manufacturers a variety of wood processing equipment, including horizontal grinders. Not taking the time to get the rock and dirt out of the material prior to grinding will result in faster wear, Stanton says.

"Care should be taken by the operators to prevent the bulk of contaminants from entering the machine," says Mark Rieckhoff, environmental segment manager for grinder manufacturer Vermeer Corp., based in Pella, Iowa. Pushing material into a pile can lead to large quantities of dirt and sand getting mixed up in the wood debris bound for processing, he says. "If possible, depending on the application and jobsite, an excavator versus a bucket loader works best to shake loose these materials before the wood goes into the grinder," Rieckhoff adds.

Manufacturers draft operator’s manuals for a reason, and ignoring the specifications listed in those manuals, particularly when it comes to regular recommended maintenance, can be a costly mistake, adds Jason Morey, marketing specialist for Bandit Industries Inc., a grinder manufacturer based in Remus, Mich. Not maintaining horizontal grinders according to the manufacturers’ recommendations and operator’s manual is among the biggest mistakes an operator can make when it comes to maintaining a horizontal grinder, Morey says. "All maintenance and operating instructions in the operator’s manual should be followed," he says.

Morey recommends a complete walk around the machine before operation. He also advises operators to check coolant levels and make sure the radiator debris screen is completely clean. "A partially plugged radiator will cause the engine to run at higher temperatures and may cause overheating," he says.

All belts, including drive, fan, feed and discharge, should be checked for the correct tension, according to Tom Eytel, director of technical services and customer support of Continental Biomass Industries Inc. (CBI) of Newton, N.H.

Morey says operator’s manuals typically contain daily, weekly and monthly checklists to follow to help operators keep track of recommended maintenance procedures.

"These are recommendations the manufacturer puts in place based on their machine as well as vendor knowledge of what the wear components need," says Rieckhoff. "Try to avoid pushing off for another day maintenance that needs to take place today."

Rieckhoff also warns operators not to overlook the bearings. "While a lot of attention is paid to bolt or weld in wear items, as these typically affect production rates of the machine, we can tend to forget about bearings," he says. "Lack of or improper maintenance of bearings can directly affect loss of production in downtime and repair costs."

Wear parts may seem like small items compared with the machine as a whole, but they play an integral role in its operation. Letting preventive maintenance slip as a temporary time-saver can lead to costly, long-term problems. On the other hand, staying on top of prescribed maintenance can mean big savings, according to Eytel. "The long-term benefits of preventive maintenance have proven to decrease downtime, improve machine fuel savings and reliability, as well as decrease the cost of replacement," he says.

"Proper maintenance will significantly reduce operating costs," Morey agrees. "Teeth that are severely worn will cause the grinder to use more fuel, increasing operating costs. Belts that are not adjusted properly will cause them to wear quicker, also increasing operating costs."

A small expense and investment of time regularly can save both time and money in the long run, Stanton agrees. "If a customer makes a habit of consistently checking the inserts in the hammermill, he can prevent excessive wear on the hammers, which takes a lot of money and time to replace," he says. "Basically, consistently checking an $18 part can prevent replacing a $130 part."

Rieckhoff agrees that it’s far better to make preventive maintenance part of the regular schedule than wait for a machine to reach its breaking point to address a problem. When a machine does break, "costly repairs that could have been avoided are now critical if the owner wishes to keep producing an end product that is sellable with the grinder, thus generating profits," he says.

Rieckhoff says when it comes to maintenance, grinders aren’t all that different from their human operators. "I like to relate any machine a customer would own as the patient, and the owner or operator as the doctor," he says. "A machine can’t talk, but it can show you signs of being ‘sick.’ Just like humans, if we ignore the symptoms our body tells us, we can shorten our lives or at a minimum, struggle until we go to see the doctor and get ‘repaired.’"

The author is managing editor of C&DR and can be reached at jgubeno@gie.net.