There are many challenges that create bottlenecks in the production of mulch. One of the most frustrating is the poor performance and failure of equipment. Maryland-based Calvert Wood Recycling wanted to eliminate that potential entirely, and recently tripled down on a full stable of new Doppstadt equipment. Randy Whitsell, general manager for Calvert, says quality and efficiency drove the decision to invest in an overhaul of machinery. “The facility had a old tub grinder and deck screen, and the product they generated was not acceptable to us,” he explains. “We also knew that operational costs were far more than they should be and we wanted to bring them into alignment with efficiency goals.”
Calvert Wood Recycling sits on 121 acres in the cozy town of La Plata, about 20 miles south of the Washington D.C. metro area. Nestled among a dabbling of state parks that rim the Potomac River, this is lush East Coast environment at its finest. There is plenty of green waste being generated by landscapers and municipalities, and Calvert has worked hard to aggressively grab market share. Since the acquisition, Calvert’s sales have grown nearly 250% in just the first year alone. Those impressive sales and production results come as a result multiple contracts won for both receiving source material and delivering finished mulch.
“We have a contract with Charles County to handle all their leaves, grass, compost, topsoil and retention soil which contributes quite a bit of supply and demand to our facility,” shares Randy. “We’ve earned contracts with several large commercial landscapers and we are pursuing some institutional contracts now too.” With a slew of major contracts to fulfill, Randy had no desire to get set back by equipment failures—hence the decision to upgrade their production machinery.
Their decision to go with Doppstadt was easy, according to Randy. “We had been researching Doppstadt for awhile and were aware of how well they perform,” he says. “We attended the Ecoverse Showcase in Cleveland back in 2015 and saw their equipment options there. [Regional Ecoverse representative] Andy [Lawrence] came out and met me on site and took us around to see the equipment perform at several locations in our area and I fell in love with it.”
Improved Quality, Efficiency and Performance
Calvert took possession of the new equipment in late spring 2016. Their Doppstadt trifecta is composed of a DW 3060K slow-speed shredder, an AK 530 high-speed grinder and an SM 720K trommel screen. Much of their material is processed directly in the AK grinder, which feeds the SM trommel to remove fines and stockpile a finished product. Their DW shredder is employed to process heavier material, such as stumps and tree trunks, providing a primary reduction before feeding the AK grinder.
Right away, Randy saw an immense improvement. “With our old tub grinder, there was no to get around sending everything through there twice,” he admits. “But the AK easily delivers 50% output on the first pass that can be screened and sold as double-ground quality mulch. The remaining 50% we send back through again. In the end we only get about 2-3% total waste in fines where before that could be as high as 20%.”
A more subtle benefit that Randy recognized is the increase wear time on the AK hammer tips. “The upswing design on the AK hammers gives us a very consistent 1.5” minus product, and have only needed to be changed every three weeks or so. We were lucky to get a week out of our previous hammers in the old tub grinder.”
Randy also appreciates the drum switch on the Doppstadt SM 720K trommel. “We use the trommel to make mulch and topsoil,” he continues. “It easily outpaces our old deck screener. And when we need to changes sizes, two people can switch out our drum in about 15 minutes. That makes production planning so much more accommodating.”
Food Waste Recycling Opportunity
Much of Calvert’s source material has been traditional green waste and land clearing debris. But working with the Maryland Department of the Environment, the opportunity to begin a food waste recycling program is being explored. As with most states, the quantity of food waste being landfilled is massive, taking up valuable capacity and generating tons of emissions. Diverting this waste not only solves a big landfill problem, but the recycled product can have huge value.
“We’ve recognized that this is a big opportunity,” Randy acknowledges. “But it is also a challenge. The Maryland Department of the Environment has been very helpful and they are excited to get this going in our state. We know there is money to be made here, but we are still working through the economics of the whole process right now.”
Food waste is just another organic source, and Calvert aims to create the same outputs from food waste as they do from grass and leaves. “This will be similar to the compost market,” continues Randy. “Bioretention soils and amendments are what we expect to generate from the food waste. But the collection, preparation and processing are different and we need to determine our best practices so we can scale this effectively.”
Organics processing has too many challenges to let equipment be the weakest link in the process. Calvert Wood Recycling wanted to transform their operation to maximize efficiency, quality and ultimately their overall profitability. Doppstadt equipment from Ecoverse delivered on those expectations, and Randy Whitsell could not be more pleased. “Our goal is to crank out as much material as we can and then go out and sell it. We need to know that peak production capacity can be reliably maintained, and our new Doppstadt machines have done just that for us.”