The emerging Green Economy has been the subject of much discussion over the past couple of years as Americans have begun to view the consumer culture a bit differently. Increasingly, refuse is being viewed differently, too. Rather than being seen as a byproduct of the consumer culture, it’s now considered part of a dynamic secondary economy, with less refuse set aside for decomposition and more repurposed in an array of recycled products.
Many MRFs are on the front lines of this change in mindset. The Green Economy’s demand for various new types of recycled commodities is pulling recyclables through MRFs more quickly than ever. In turn, MSW managers are increasing the automation level of their MRFs significantly. Manufacturers of automated separation equipment are responding to a demand pull within their own market as part of the overall chain reaction.
Proof of how the marketplace is adapting equipment to automate the separation of recyclable materials can be found at Baltimore-based Canusa Hershman Recycling Co.’s new single-stream, 50-tons-per-hour MRF in Manassas, VA. The new facility started up in April 2009, boosting the company’s processing capacity in the region by supplementing an existing facility about 30 miles away in Springfield, VA.
The existing facility was processing dual-stream residential recyclables: fiber as well as rigid plastic, aluminum, and steel containers. Jonathan Sloan, president, reports that the existing system was only about eight years old but was outdated, particularly for processing the containers. Recent equipment advances meant that construction of a new state-of-the-art facility made more financial sense than retrofitting the existing facility. Now the old facility takes source-segregated materials and single-stream recyclables, which are transported to the new MRF in live-floor trailers.
The Manassas MRF is a turnkey facility designed and equipped almost entirely by Van Dyk Baler Corp. A key piece of equipment is a Bollegraaf HBC 140 baler for fiber materials. The machine’s compaction force can be adjusted to yield a rate of 25 to more than 50 tons per hour with a cycle time of 16 seconds. It is also equipped with a 3-horsepower motor, Swiss-manufactured internal gear pumps, and a pre-press flap designed for optimal charging as well as optimal motor power and power consumption.
Other key machinery includes a Harris 918W two-ram baler for plastics and metals and a Van Dyk drum feeder that loads the main feed conveyor. “The drum feeder, while they’re not totally novel or unique, they’re becoming more mainstream,” says Sloan. “The drum feeder isn’t as prevalent as direct feed to a conveyor, but a drum feeder provides two main advantages. It allows for some unattended feeding of the system because the wheel loader can deposit single-stream recyclables into the hopper while the unit is automatically discharging. The other advantage that may be more important is that it provides a very consistent, metered flow as opposed to the wheel-loader operator pushing large amounts of material onto the feed conveyor, overwhelming the system and personnel. By presenting the material to the system in an even, consistent fashion, you get better productivity.”
After the drum feeder, contamination is removed along a presort station and then OCC is mechanically removed by a triple-deck OCC screen. From here fiber and containers are separated by a series of Lubo screens and optical sorting technology. Additional mechanical, optical, and manual processing is employed to separate materials into individual commodities held in self-feeding bunkers, from which they are conveyed to their respective balers. Sloan says he thinks that the facility’s higher-than-average level of automation maximizes the laborers’ productivity because a high degree of separation has occurred using various mechanical and optical processing technology.
Canusa Hershman uses CIE Trade software to manage facility data. The industry-specific program tracks inbound and outbound volume and also has a back-office component for payables and receivables. Each transaction record includes sales, purchase, logistical, and accounting information for each transaction on a worksheet.
Sloan believes that advances in automation will continue. “The industry will continue to evolve in terms of what materials are recovered and what systems and equipment are available to handle different commodities and the ever-changing composition collected from residential and commercial sources,” he says. “It’s constantly evolving and changing. It’s a very dynamic industry. Everybody’s looking for increased diversion.”
Public Facility Segregates High-Value Stock
Even a publicly owned MRF can attempt to realize the revenue potential of higher-priced commodities that entered the facility as recyclables. Such is the case in Appleton, WI, where Outagamie County operates the $9.9 million, 50,000-square-foot Tri-County Single-Stream Recycling (SSR) facility, one of the largest publicly owned MRFs in the country.
When it began operation in July 2009, the single-stream SSR served more than 60 communities and 200,000 households throughout Outagamie, Winnebago, and Brown counties in northeastern Wisconsin but had the capacity to serve significantly more. Initially processing 50,000 tons (3,000 semi-truckloads) of recyclables per year, the 25-tons-per-hour facility is capable of processing more than 80,000 tons per year. The new facility has allowed all 32 Outagamie County communities to start utilizing single-stream curbside containers for semiautomated collection. Winnebago and Brown counties provide dual-stream recyclables, with paper and containers separated.
Phil Stecker, P.E., BCEE, director of solid waste for Outagamie County, points out that the Bulk Handling Systems (BHS)–designed SSR processes about 95% of the incoming material into saleable commodities. Side-loading refuse haulers from Outagamie County and transfer trucks from Brown and Winnebago counties back into the tipping area via large roll-up doors and dispense their loads. A wheel loader performs three functions on the tipping-area piles, Stecker explains. One is simply creating more floor space by consolidating the small piles into larger ones. “Another function is to do some blending of the loads,” Stecker says. “One load might be a certain kind of material like paper; another load might be a lot of container material. The plant functions much better if we have a well-blended material.”
The third function of the wheel loader is charging a 60-cubic-yard BHS metering drum that evenly dispenses material onto the main infeed conveyor belt. The metering drum can operate unattended for about 15 minutes, according to Stecker.
The main conveyor first transports the material to a presort station staffed by up to five employees who pull out fugitive material. The enclosed heated and air-conditioned station is located 16 feet above the main facility floor and equipped with six drop chutes that feed rolloff containers below. A priority here is pulling out long, stringy fugitive material like cord or rope that can get wrapped around screen shafts, Stecker notes.
The remaining “clean” stream of recyclables is then conveyed to the automated portion of the SSR, which cost $7.3 million to construct and start up. A BHS/NRT MultiSort optical sorter separates polyethylene terephthalate (PET) plastics from the stream and a Dings Co. Electro Magnet and BHS Eddy Current Separator remove metals. “The heart of the plant is the disc screens—we have a series of four,” says Stecker. A BHS OCC Separator is for old corrugated cardboard (OCC). BHS NewSorter No. 1 and No. 2 disc screens take out newsprint. A BHS Polishing Screen does the final separation of small paper fiber from containers.
Stecker reports that the facility captures nearly 100% of “high-value” material, such as No. 8 newsprint, and residue values are estimated at less than 3%. “Instead of capturing paper and selling it as a mixed paper, which has the lowest value, our goal is to separate No. 8 newsprint, which is a little higher quality than, say, No. 6 newsprint. The disc screens do a good job of separating the higher-quality materials like No. 8 newsprint.”
A few other markets are emerging for the SSR’s processed commodities, including glass. Stecker reports that the county has had discussions with a Wisconsin company that processes recycled crushed glass for use as coarse granular aggregate in parking lot paving; rainwater percolates through the aggregate, minimizing runoff. “Another market we’re watching is the ‘No. 3 through No. 7’ plastics market, which isn’t well established at this point,” Stecker says in regard to grades other than PET and high-density polyethylene (HDPE) that are being recycled into commodities with increasing frequency.
Other equipment used in the facility includes a BHS Glass Cleanup System, which removes shredded fiber, dirt, and debris from 2.5-inch broken glass product; Keith Walking Floors for OCC and newsprint collection areas; and a BHS dust-control system.
With the various commodities separated, an IPS Two-Ram 200-horsepower baler compresses them and wraps wire ties around each bale. The bales are kept in a storage room until enough are created for a truckload. At that point, the department calls a buyer and a truck backs up into one of two loading docks, where a forklift loads the truck. The forklifts are also used to remove bales from the baler and stack them in the storage room.
The SSR also incorporates advanced information systems. The weighing process, which works for both the SSR and the county’s landfill, uses attended and unattended systems alike. The weigh scales are from Badger Scale. On the unattended system, a weigh-scale sensor on the automated scale reads RFID tags mounted on the dashboards in some trucks. Advanced Weighing Systems Interact software stores customer and truck data. Each transaction is recorded, and the county totals the transactions and produces invoices for each account at the end of the month.
New Equipment for New Markets
Recovery 1 of Tacoma, WA is an operation that specializes in construction-and-demolition (C&D) waste recycling, having started in 1993 as a wood-fuel and wood-pulp recycler. Recent equipment upgrades allowed the company to divert more than 98% of material from its intake, including alternative daily cover (ADC) in 2008. Besides the ADC, the company processes and ships two grades of wood-derived fuel, wood-pulp furnish, three colors of wood mulch, gypsum powder, processed planting media, four grades of steel, two grades of copper, aluminum, corrugated cardboard, mixed rigid plastic, mixed film plastic, PVC siding, N-6 carpet, vinyl-backed carpet, shredded carpet used as oil absorbent, carpet pad, rocks, bricks, concrete, porcelain, glass, ceiling tile, and fiberglass insulation.
In 2007, the company purchased an SSI Shredding Systems Pri-Max PR-4000 primary reducer to work in conjunction with a West Salem Machinery model 5472 vertical feed grinder. The PR-4000 removes nearly all steel pieces that might damage the vertical feed grinder and is equipped with a reverse gear to further minimize steel pieces. The steel is captured by an overhead magnet, and the non-steel material is conveyed across a sorting line and under a magnetic head pulley before the vertical feed grinder provides final grinding. The vertical feed grinder has a large rotor assembly with 27 swing hammers weighing 150 pounds each. The machine crushes and shears the feed material down to a typical size of 18 inches. The vertical feed grinder also has a ballistics chute attachment on the feed conveyor and two magnets downstream of the machine further minimize fugitive steel in the wastestream.
Additionally, a two-stage West Salem Machinery WSM 72-15 disc screen is used to automatically separate materials. General Manager Terry Gillis says that the screen is designed to accommodate two material sizes and an overhead vacuum system also pulls out lightweight plastics, helping to mechanize the separation process for wood fuel production.
The equipment in Recovery 1’s MRF allowed the company to process and ship 67,522.31 tons of refuse in 2008 at an average of 267 tons per day; the facility operates five days a week and is closed for seven holidays. Of the total processed, 26.87 tons (about 0.04%) consisted of nonrecyclable residuals and 12,506.78 tons (18.52%) were used as ADC. Recovery 1 tracks these quantities closely using a monthly wastestream analysis because many of its construction contractor customers apply for construction waste management points under the US Green Building Council Leadership in Energy and Environmental Design (LEED) program and Gillis wants to verify the validity of the points. Gillis notes that 10% of the ADC is deducted because the landfill informed the company that up to 10% may not be utilized as ADC due to need and storage capacity. The LEED recycling rate excluding ADC is 81.44%.
Over the years, the company has processed a widening array of materials for new markets. Most recently, it began processing fiberglass insulation and ceiling tiles through its baling system as a pilot project for Armstrong Industries. Recovery 1 hand-sorts these materials and bales them using a 100-horsepower Harris HRB baler to ensure full segregation.
Recovery 1 is also focusing its equipment upgrades on getting materials in and out of the MRF efficiently. Gypsum powder, which is sold to Portland cement manufacturers, is loaded directly into trucks from hoppers. Wood is loaded into trailers with a wheel loader. Bales are loaded into containers and trailers using a ramp and a forklift equipped with a homemade bale clamp. Most material has come in via truck until recently, when the company had a rail spur constructed, primarily to accommodate railcars of waste railway crossties and timbers. The use of the Pri-Max PR-4000, which is effective in separating steel from other materials, is key to the recently developed capability of processing railway crossties. The size of the spur is being increased to accommodate a 50% increase in train traffic, according to Gillis.
Recovery 1 uses an integrated Compro Systems AutoPro truck-weighing and Sage North America system for weighing and billing. Most materials are billed by the pound or ton, Gillis points out. Mulch is billed by the yard, but everything is weighed for reporting purposes. The system tracks data such as commodities, city of origin, county of origin, delivery vehicle, and material type, which allows the company to produce detailed reports. For example, Recovery 1 runs monthly reports on how much material particular counties have contributed to the intake stream.
Other specialized equipment that can be integrated into a MRF to aid in efficient wastestream processing is available to MSW managers.
The Premium Bulb Eater crushes spent fluorescent lamps of any length into 100% recyclable material while capturing more than 99.99% of the vapors released, according to Air Cycle Corp. The system, which is mounted to a 55-gallon container, reportedly can hold up to 1,350 4-foot fluorescent lamps. The unit is equipped with a side-mounted dust-filter unit with an H.E.P.A. filter that works in conjunction with an activated carbon filter located in the steel canister. The activated carbon filter captures and neutralizes mercury vapor released from the lamps during crushing.
After lamps have been crushed, full drums are transported to one of a network of permitted facilities. The components are recycled in machines that break down the lamp and then separate the glass, metal, and mercury—all of which can be reused. A certificate is issued to the customer to document that the lamps were properly recycled at a permitted facility.
According to the company, the unit frees up valuable storage space normally filled with boxes of spent lamps, reduces handling and related labor costs, and typically cuts recycling costs.
The company estimates that crushing rather than boxing the lamps can save roughly 20 hours of labor per 1,000 lamps and total savings of 10 cents to $1 per lamp have been reported. Lower mercury emission rates equate to safer employees and lower liability, the manufacturer adds.
Rolloff recycling containers from Bakers Waste Equipment have multiple designs for various recycling applications. These include rectangular or tub-style containers; octagonal, A-frame, or flat-roof designs; and load openings with either hinged or sliding doors. Hinged compartment dividers provide separate recycled items.
Multiple sizes are also available. All containers are 22 feet tall and 8 feet wide. The 20-cubic-yard container is 53 inches high, the 25-cubic-yard container is 57 inches high, the 30-cubic-yard container is 64 inches high, and the 40-cubic-yard container is 82 inches high. Heavy-duty models are also available with quarter-inch floor plates and three-sixteenth-inch sidewalls.
The containers’ construction features understructures with 3-inch channel weighing 4.1 pounds per foot on 16-inch center, two gussets per cross member, main rails with 2-by-6-inch tubing, standard three-sixteenth-inch steel plate floors, 12-gauge steel on the sides and front, side braces with a 4-by- 5-inch formed channel on 38-inch centers, and a rear door with a three-point latch and safely chain.
An example of a company maximizing processing and logistical efficiency through automation is Manassas, VA–based EnviroSolutions’ new rail transfer station at the Port of Newark, NJ, which began operation in February 2009. “The principal goal of the facility is to maximize the efficiency of the baling and railing of waste,” Marc Shaener, EnviroSolutions’ director of market development, says of the 40,000-square-foot, 2,000-tons-per-day facility.The operation uses shredding and magnets to divert nearly 100% of the ferrous metal from the commercial and residential MSW stream, and the metal is transported by rolloff trucks to a scrap facility. The operation uses shredding and magnets to divert nearly 100% of the metal.
A Model 5100-SE Stationary Electric Material Handler from Northshore Manufacturing loads two SSI Shredding Systems Pri-Max PR-4000 Primary Reducers. The material handler features a horizontal lift capacity of 39,145 pounds at a 20-foot reach and 15,008 pounds at a 47-foot reach, and 360-degree continuous rotation powered by two swing motors and planetary gearboxes. Shaener reports that nearly everything in the MSW stream is shredded in order to maximize the density of bales and to facilitate the removal of metals downstream. The shredders use low-speed, high-torque operation to break up masses of homogenized refuse at a rate of up to 75 tons per hour.
After shredding, the material is conveyed under a Dings Co. magnet that pulls out the metal items. From there, the MSW is baled using two FAES HDR 300 balers. The material enters the baler’s charge chamber and a compression ram compresses the material into a block shape in three or four strokes. Once the bale density is sufficient, the baler’s ejection ram pushes the bale out of the chamber and the bales are wrapped in plastic ties and plastic wrap by either of two CrossWrap 2500 bale wrappers. Each dimension of the bales is wrapped in plastic film. “The wrapping in plastic prevents any of the material from coming in contact with the environment or leaking, and it contains any potential odors while in transit,” says Shaener. “A lot of that was required by the rail companies.” He points out that CSX Corp. requires MSW to be wrapped in plastic for hauling in gondola cars, which may be in transit for long periods and are sometimes staged near populated areas.
After bales are processed, they are staged via forklifts near a railcar loading area, where a Sennebogen 825 M material handler loads the bales into the railcars using a Waste Bale Grapple from Northshore, which is designed to clamp the bales without damaging them. The goal is to load the railcars up to about 100 tons, according to Shaener. “We installed a scale after the ejection chamber, so we can monitor the bale weight to make sure the mix and flow of waste is resulting in the maximum density and weight of each bale,” he says. “It costs the same amount to move a railcar regardless of how much weight is in it.”
The bales are shipped all the way to Big Run Landfill in Ashland, KY, which can accommodate 5,000 tons of refuse daily. “We have to ship that waste farther out of necessity,” Shaener says, referring to the dwindling space for landfills in the Northeast. “That’s why we developed our system—we didn’t want to be shipping this waste farther without trying to realize the efficiencies of transportation through rail, including reduced carbon output and taking trucks off our busy highways.”