Cutting through potential problems
A scrapped roll-off container is fed whole into a large incline shear.
Photo supplied by Vezzani S.p.A.

Cutting through potential problems

Scrap metal shears are being designed to deal with dense, bulky scrap in all climate conditions.

January 14, 2020

Powerful scrap metal shears and baling machines have long been asked to perform difficult tasks in large-volume applications.

The growing global nature of the scrap metal industry has meant industry suppliers have increasingly designed these machines to handle an even wider variety of scrap and to be able to withstand difficult weather conditions, according to recycling equipment suppliers.

Running hot or cold

Pierluigi Sambolino of Ovada, Italy-based Vezzani S.p.A. says providers of large capital equipment often custom-produce large shears and balers, knowing ahead if time if a machine may be destined for an extreme weather destination, “and we take this point into account.” Adds Sambolino, “In reality we can install our machines anywhere, [and] our design is adapted to suit.”

That does not mean operators can neglect maintenance tasks that could become even more vital when extreme heat or cold sets in. According to Jose Pereyra, general sales manager of United States-based Sierra International Machinery, “In extreme operating conditions, all [maintenance list] items are even more important.”

In locations experiencing prolonged heat, naturally, a machine’s cooling system deserves attention. “For hot climates, if you have radiators keep them clean and free of dust by blowing them out with compressed air,” says Sambolino.

The hydraulic system also bears watching, he adds. “Make sure that the air flow in the hydraulic station is sufficient to keep the ambient temperature down to reasonable levels. It may be necessary to install an air conditioner in the room that contains the electrical cabinet,” says Sambolino.

“Make sure you keep your heat exchangers clean,” Pereyra cautions operators of shears and balers who are working in extreme heat. Sierra offers a broad range of shears and balers ranging from large stationary machines to portable models that can be deployed in numerous (and often difficult) environments.

Remarks Sambolino, “Hot also means dusty, so make sure that oil tank air filters are in place and maintained.” Regarding filters overall, Sambolino comments, “Keep the oil filters in working order so as to avoid the cooling system becoming blocked, potentially with debris. If you have a broken filter, the risk is any debris the filter should stop could end up inside the radiator, which then slows down the oil flow.”

This, says Sambolino, can lead to insufficient oil cooling. “In very hot climates we install water tower- type cooling, and here it’s important to make sure there is sufficient water flow to keep the cooling tower topped up.”

For a machine heading to a cold climate, Pereyra advises, “Make sure your oil is warm, and make sure you cycle your machine before you go into full production.” Safety also needs to be kept in mind during winter weather, says Pereyra, who adds, “Slippery surfaces can cause safety hazards.”

Sambolino says Vezzani “will build the machine in a way to overcome the risk of brittleness of the structure.” He continues, “We have machines that work at -50 Celsius (-58 Fahrenheit) regularly. We always take the necessary steps to adapt our machines to the local conditions.”

If oil becomes too hot or cold, “Our machinery will not allow a cycle,” says Sambolino. “Instead, the machines will [send] oil to be cycled through pumps until it is at a minimum running temperature or to run only the coolers.”

In extreme winter conditions, “It would make sense to heat the pump house and electrical room in a cold climate,” says Sambolino. “Machines that are running tend to warm up on their own due to friction. So, starting up is the main problem on a freezing day if you haven’t kept the oil warm overnight. Also. it’s best to use the machine lightly until it is warmed up and at a safe temperature,” he advises.

“As long at the operator carries out checks and maintenance in accordance with the manual, there will be no problems,” states Sambolino. In newer machines, if they get “too hot or cold, the PLC [programmable logic controller] will put the machine into an alarm situation, thereby avoiding damage.” Thus, he adds, “It’s important that all components on the machines are working--heat sensors for example.”

Several ounces of prevention

At the operations level, those feeding either a shear or a baler need to remain vigilant about tanks or cylinders containing fuel or other potential causes of explosions.

Pereyra points to “any type of cylinder or closed vessel [containing] propane, oxy or acetylene” as items to watch for, plus “munitions of any kind and cars with fuel remaining in the tank.”

Some equipment features an “open box design [that] doesn’t try to contain the fire or pressure wave,” says Sambolino. This can reduce equipment damage, but, “It’s important to put the fire out ASAP,” he comments.

On every operator’s “to do” maintenance list, says Sambolino, should be checking oil and hydraulic fluid levels and looking for leaks; keeping an ear open for “strange” noises or vibrations; checking the PLC screen for warning messages; visually inspecting wear parts such as knives, liners and guides; and otherwise following maintenance manual recommendations regarding changing filters and fluids “at specific intervals.”

In addition to “following a strict daily inspection and maintenance routine check list,” Pereyra advises yard managers to emphasize cleanliness as a best practice that can help prevent numerous problems from occurring.

Incline shears have been gaining attention in the scrap recycling sector, and Sambolino says this is in part due to their ability to handle many types of scrap without risking downtime caused by catastrophic failures.

He says Vezzani’s PC-AC incline shear, as one example, has been designed to allow large materials to be fed into the machine without risking any damage to the shear. “If an item cannot be processed it can be lifted out of the feeding box pretty much intact--as it was put in—without wasted time and lost production time,” states Sambolino.

If a bulky item needs to be removed, it can be plucked out and torch cut, he says, and “once prepared, it can be fed back” into the incline shear for a second attempt.