Follow the stream

Photos courtesy of Sherbrooke OEM

As an industry that relies heavily on end markets, the equipment and design of a typical construction and demolition (C&D) facility is ever-changing. A variety of materials are accepted by C&D recyclers, including wood, aggregate, scrap metal and gypsum, and the processing methods used for these streams often vary by region.

Sherbrooke OEM, a Canadian waste and recycling equipment manufacturer, has seen firsthand the way fluctuating end markets can affect facility planning, design and upgrades at C&D recycling facilities.

“Every place in the U.S., every town, every state, the materials are different, and the markets are very different,” Sherbrooke OEM Vice President Ian Levasseur says.

Serving clients throughout the U.S. and Canada, Levasseur says every market poses a unique challenge.

“It doesn’t matter what area you’re in,” he explains. “In Florida, for example, they’re lucky in one way where a lot of their construction is made with concrete. By making a clean aggregate product, they can reuse it for purposes such as filler, base and for use in commercial areas. So, they have that advantage over other people in the Northeast.”

High volume, high reward

While C&D recycling facility operators within regional markets could process different materials in any given facility, one factor has remained consistent among recyclers in the U.S. Levasseur says there has been a significant uptick in recyclers looking to design higher capacity systems.

“Going back five years ago, we had a lot of little guys that would come in and want to process about 150 tons a day, but we really don’t see that anymore,” he says. “I don’t know if it’s still a market that exists, but for us now the trend is high-volume systems.”

This can be credited, in part, to ongoing labor shortages within the waste and recycling industries, leaving many small-scale processors struggling to continue operations.

“It’s harder, especially in the last two years with the pandemic, to get labor and keep that labor,” he says. “It’s harder to justify automating a small system in regions with low tipping fees, however, it’s still a possibility if the markets are right.”

To mitigate the labor shortage, Levasseur says more recyclers have begun relying on automation and optical sorters to fill those gaps.

“There are still plenty of [smaller recycling operations], but they’re more automated systems,” he says.

Although robotics offer several benefits, including less reliance on manual labor, Levasseur notes the high capital costs associated with automation make reliable end markets that much more important.

“I think this is the reason we see bigger [companies] gaining dominance in the industry because, when you control that much volume, it’s easier for you to make products for different markets,” Levasseur says.

Considering market factors

When it comes to designing a facility or choosing the right equipment, there are several steps an operator can take to ensure the highest efficiency and return on investment while also considering the role of regional markets.

“The first step, which is also the easiest, is you need to start with the right material composition,” he says, adding that having a good understanding of the materials entering a facility will help determine which equipment to include in the system.

“When we design a system, material composition and throughput are the two main factors that start the process,” Levasseur says. “As you start to design it, end markets become very important, but without knowing what and how much is coming in, it’s hard to start designing something.

“End markets are where the customer is really involved in the design process because they know more about their local markets than we do,” he adds. “So, we get the customer involved to figure out the size and quality specifications needed for specific markets.”

Levasseur says the design team looks at all incoming material, including wood, aggregates and ferrous metals, as well as fibrous materials such as cardboard, to choose what equipment makes the most sense.

“Cardboard is a great example because when you ship cardboard looms, you’re not making close to the weight on the trucks. However, if you’re only going 2 miles and you have to deal with someone that’s going to bale it for you, or if you have another facility to bale it, then you don’t need a conveyor or to feed a baler in that specific facility,” he says.

Bringing in the robots

In terms of sorting, Levasseur says that while robotics have gained popularity among C&D recyclers, they still are far from the norm.

“I don’t think robots are there yet. There are good robots … but I think they should be placed in complement to optical sorting or a quality control position and not a primary position because their pick rate in C&D is really slow,” he explains.

To best take advantage of robots and optical sorters, Levasseur says it is critical that material be presented to them in a single layer.

“If you send 2 feet of material [down] the belt, the robot is not going to be able to do anything because it’s just looking on the surface. That’s why you need to present a single layer flow with some space between the material in order for the robot to do its job,” he says.

Sherbrooke OEM has begun adding robots at some smaller plants it has equipped to help increase efficiency.

“We’ve added automation at a plant north of Quebec—a small plant, only 25 tons per hour. We [haven’t] put robots in yet, but we use optical sorters to do our wood and preclean before it’s presented to a human for quality control,” Levasseur says. “Their goal is to add a robot there at some point, but right now they’re using [manual sorting] for budget reasons.”

Looking toward the future, Levasseur says he has no doubt robots will become an integral part of large C&D recycling facilities as technology continues to advance. The artificial intelligence systems on the robots work well, he adds.

“The speed and the weight of the components are really what’s making robots difficult to put into the systems,” he says.

Ultimately, Levasseur says he believes lighter fractions will be handled using a fully automated sorting process, while heavier material will be left for manual separation.

“I think human pickers are going to have an easier job as they are put in more accuracy positions,” he says. “For typical single stream systems, robotics work really well because they’re fast. But, when it comes to C&D, we need to be a little bit slower and be able to lift a little more weight.

“We’re not far from getting a downstream that’s fully automated, but functionality and high throughput are the key.”

The author is the associate editor of Construction & Demolition Recycling. She can be reached via email at hrischar@gie.net.