Integrated waste processing - a new concept for material recovery facilities (MRF) - has been pioneered in a small, rural community in the Deep South.
Unlike conventional MRFs, the $53 million plant, owned by the Solid Waste Management Authority of Crisp County, Ga., will not only separate waste, it also will produce and market raw materials ready for manufacturing processes and for consumer markets.
"Most MRFs separate materials then market [them] to processors that supply manufacturers and consumers," says John H. Hayes, chairman and CEO of Municipal Waste Management (MWM), the Atlanta-based firm that designed and built the facility. "Our idea is to continue where MRFs leave off."
MWM will operate the facility under a 5-year contract.
The processes and procedures that drive the plant were developed by Wastech Equipment LLC, an Atlanta-based engineering firm, and MWM. These engineers selected the equipment and integrated each piece of hardware into a processing system that achieves the goals set by Crisp County.
Wastech specified approximately $12.6 million in processing equipment, some of which handles conventional MRF tasks in conventional ways and some of which automates those tasks with state-of-the-art advancements in equipment design. All of the equipment has been chosen to support the concept of integrated waste processing.
The idea of integrated waste processing has been around for years. While definitions of the term vary, Hayes says it is the complete integration of hauling, material recovery, material processing and marketing. "The key has been to integrate the end markets into the design of the facility," he says.
The idea extends the facility's design considerations to include finished products. First, MWM determined which end products this facility could produce and who would buy those products. Then, it identified end-uses for recyclables.
Potential manufacturing customers needing raw materials liked this new concept. In fact, early in the design process, MWM received letters of intent from manufacturers agreeing to purchase separated green and clear PET products; natural and mixed HDPE products; junk plastic; ferrous and non-ferrous metal products; white goods, including any gases; No. 8 and No. 6 newsprint and old corrugated cartons; and glass.
Composting using food wastes and items such as soiled paper and tobacco waste, also plays a large role. "Once we get state certification, we'll produce a compost product suitable for marketing in bulk and in bags," Hayes says.
In every case, except metals, the materials flowing into the Crisp County plant will flow out as a finished product. "In this plant, metals will not be mill ready," Hayes says.
Once MWM established its marketing concept, Wastech created the system. Specifying and buying equipment to fit specific concepts involves evaluating a number of options, according to Rodney Bowers, Wastech's executive vice president and CEO. "There is a lot of new technology today," Bowers says. "Advances in other industries, such as metallurgy for example, now have been applied to waste processing. As a result, you see better designs and fabrication techniques, along with better overall quality. And, as the waste industry has grown more sophisticated, the number of good suppliers has grown."
However, specifying a system for the Crisp County facility demanded the careful planning of its configuration and redundancies, equipment selection, logistics, warranty negotiations and financing.
Making Room for the Trash Because approximately 87 percent of the waste stream will be segregated, processed and reused, the plant had to be capable of handling 1,700 tons per day.
The remaining 13 percent will be baled and placed in an on-site Subtitle D balefill. The goal is to take the place of 16 landfills that are closing across southern Georgia.
In addition, a large composting area will produce an estimated 206 finished tons of compost and 190 tons of aggregate and ground cover daily.
The 54-acre landfill and 9-acre composting area limit the space available to the processing plant. As a result, it had to fit into a 300-foot by 635-footprint jammed with conveyors and processing equipment.
This created difficulties for the plant design, Bowers says. Crisp County could buy more land to build a plant with a larger footprint or hold firm on site costs and pay more to design a two-level plant.
"We went up with a two-tiered processing system," Bowers says. "That raised the cost of the plant in terms of the design and layout of the equipment."
More space constraints and cost issues arose from the redundancy needs of the front-end MRF system. The plant's permits require that all waste materials move out of the facility within 72 hours.
As a result, Wastech engineers purchased a redundant front-end system with two bag openers, two trommels, two low-speed shredders and two conveyor lines with picker stations.
Bowers notes that "redundancy carries higher up-front costs," because you pay for more equipment plus its installation and check-out. The trade-off is the cost for repairing a major piece of equipment within a day or two to ensure that you fulfill your permitting requirements.
"A redundant system is a form of insurance, and determining how much of this kind of insurance you need is an important part of equipment buying," he adds.
Chewing up Waste, not Time The heart of the Crisp County plant are nine major systems. In purchasing equipment for those systems, Wastech conducted extensive research into competing technologies, considering issues such as processing requirements, space allocation, reliability, delivery logistics, installation, modification needs, cost, warranties and financing:
* Bag openers. Wastech opted to start the line with two model 84 Lib-A-Rader bag openers. The largest bag openers produced by Rader Resource Recovery Inc., Memphis, Tenn., this equipment can open up to 65 tons of bags per hour.
When selecting the bag openers, Wastech visited several facilities unaccompanied by a manufacturers' representative. "We tried to do this with every piece of equipment we selected," Bowers says. "We wanted a candid assessment of the reliability, ease of operation and problems."
Wastech spec'd machines with moving tines as opposed to knife blade openers or stationary blade openers. The specifications also called for an independent control panel on the machine itself.
"We wanted a control system that would enable the operator to pull the tines up and allow inappropriate material that might damage the tines to flow through on the conveyor to other areas of the system," Bowers says.
* Trommels. Triple S Dynamics, Dallas, supplied two large trommels for the Crisp County facility, building both to Wastech's specifications. "Size was important with the trommels," Bowers says. "Our application involves a large process flow, so this equipment must handle 90 tons per hour per trommel. That required machines 10 feet in diameter and 74 feet long."
Selecting a supplier for large trommels involves making judgments about logistics and installation issues. For example, the Triple S trommels traveled from Dallas to Crisp County on a special truck following a special route created by computer routing software.
"The route had to accommodate the height of the machines and the turning radius of the vehicle," Bowers says. "We had to inform the departments of transportation in the states we were passing through. In some cases, the state helped us to find a better route. We also tracked the progress of the trip with a global positioning system."
Such considerations raise the cost of any large piece of equipment. According to Bowers, much of the large Crisp County equipment required special procedures to ship, off-load and place. Costs that often are overlooked include transportation, cranes and installation labor.
"You have to plan carefully," Bowers says. "If you arrange to have a crane on Friday, and the equipment doesn't show up until Monday, you've created a cost problem."
To control these costs, it's important to establish what will incur up front, Bowers notes. At that point, the parties can negotiate and massage potential problems. If the buyer neglects to negotiate the cost of lifting a machine off the truck or misses a delivery time by 48 hours, the facility will face cost overruns as a result.
* Balers. Wastech purchased four balers from the Harris Waste Management Group, Baxley, Ga. Two Harris Selco model HLO-8110 AR 150 horsepower (hp) machines with fluffers bale landfill material that cannot be made into commodities. These balers are positioned in the line between the bag openers and the trommels.
The other two balers include another 8110 model running at 150 hp and a Harris Selco model HLO-7110 AR 100 hp machine. These handle commodity products after they move past the main picking platform.
* Low-speed shredders. Mac Saturn Shredders, Grand Prairie, Texas, supplied two shredders - one for each of the facility's two lines.
"We bought off-the-shelf shredders because we were able to specify the width of the shredding wheels and the tonnage per hour," Bowers says.
"We needed approximately 50 tons per hour of throughput, with a surge capability of 65 tons per hour."
* Plastic separator. Wastech spec'd a system supplied by MSS, Nashville, Tenn., to separate plastic materials. "This equipment uses optical sensors and X-ray emitters to distinguish colors and polymers and to send specific materials to one of five separate conveyor lines," Bowers says.
Although the automated plastic separator is expensive, Bowers says the higher cost is justified because it separates plastic more accurately than human pickers. Bowers also explains that plastic separation "can operate independently of pickers at earlier stations. For example, we can stop the plastic separator and still fill the bunker with unseparated plastic material to be sorted during another shift."
The plant also has a plastic debaler feeding another line into the plastic separator.
The debaler allows the plant to take in baled plastic from other sources, run it through the separator and send it to the grinding and washing line. "This allows us to use the separator even when there is no trash in the facility," Bowers says.
* Plastic grinders and washers. The largest system in the Crisp County plant is the plastic grinding and washing equipment, which includes four silos, five grinders, four float-sink tanks and several dryers and accumulators.
MA Industries, Peachtree City, Ga., supplied this system, which helps transform a MRF into an integrated material processing facility.
The plastic separation system feeds material into the grinders that produce plastic flake for temporary storage in the plastic silos.
From there, conveyors dump the flake into float-sink tanks that wash the material and remove labels and adhesives. The float-sink tanks also use specific gravity to separate polymers further.
"After drying the material, you're left with good flake plastic that manufacturers can use as a raw material," Bowers says. "We could have baled the plastic before grinding it, but flake is a more valuable product in the marketplace."
* Aggregate separating system. Triple S Dynamics provided the aggregate separating system, whose components are stacked on top of the other and rise to the facility's third floor. Material feeds in from the top and works its way down through a gravity separator, an inert separator and a vibratory shaker. A hammermill supplied by Jeffrey, Duncan, S.C., also is part of the system.
"This system separates out rocks, stones, broken glass, coins, batteries and other materials that are less than 2 inches in diameter," Bowers says. "The plant then will grind the stones and some of the glass for use as a composting feedstock. The rest of the material from this line goes to the landfill."
* Conveyor system. The conveyors that feed the picking stations, bag openers, trommels, aggregate system and other plant systems were built by Norcon Systems Inc., Rome, Ga.
The conveyor line includes hoppers, shoots, plastics perforators and glass breakers to help reduce the materials' volume. The components of the facilitywide conveyor network make it the most expensive system in the facility.
* Mixing drum. Leftover organic materials and some of the paper from plant processes flow into a 50-foot long, 8-foot diameter mixing drum supplied by Bouldin and Lawson, McMinnville, Tenn. The drum adds water and nitrogen pellets through a nozzle system to aid the chemical breakdown of these materials, which then become part of the feedstock for the composting system.
* Windrow turners. Wastech specified two FM18 windrow turners with customized irrigation systems from the Frontier Manufacturing Co., Woodburn, Ore., to anchor the facility's composting system. The 18-foot by 7-foot machines are powered by 460 hp diesel engines.
Warranties and Financing Wastech paid particular attention to warranties and financing when evaluating equipment.
The suppliers offered warranties with different terms, varying from 90 days to 18 months.
In light of the complexity and interdependence of the systems in the plant, Wastech executives decided to have at least 12 months of warranty support for each piece of equipment. "We negotiated with suppliers offering shorter warranties to extend their coverage," Bowers says.
Did extending warranties raise the cost? Not in this case, according to Bowers. Because of the visibility of the project, suppliers generally acquiesced. Wastech also negotiated a payment plan with the equipment suppliers, based on the financing method favored by the Solid Waste Authority.
The authority acquired financing for the entire project, including the equipment, through a consortium of banks. Under this arrangement, the financial institutions required performance bonds on all equipment and payment bonds on all suppliers.
Once suppliers satisfied the bond requirements, Wastech set up the payment plan, which began with deposits and included additional payments as fabrication progressed through installation.
"The authority controlled the money," Bowers says. "It paid us based on our documentation of the progress of each component in the system, and we issued the progress payments to the suppliers."
After a period of successful testing, the Crisp County plant began accepting its full amount of waste on June 1, 1998.
As the amount of waste produced annually grows and as recycling awareness and acceptance increases, so does the need for equipment to manage this waste. Because this equipment is not cheap, demands are rising as buyers seek the most cost-effective solution for good used and refurbished recycling equipment.
The main advantage to buying new equipment is maintenance support and warranties. Not all used equipment comes with a warranty, although some dealers refurbish used equipment, then guarantee it.
Two key pieces of recycling equipment - tubgrinders and shredders - usually have:
* replaceable and/or repairable components, and
* the equipment manufacturer's brand of hammermills and rotors, which vary in size and can be replaced by the new owners.
Unless the equipment has been abused or not maintained, 5- to 6-year-old used equipment can sell for less than half the cost of the same new equipment and still operate at close to the same costs as new equipment.
Before buying used, assess your operational needs, such as production rates and operating costs. Be specific about the type, size, condition and end-use of the material that will be processed.
As a buyer, you must be aware of the total hours on the used equipment and should ask for all maintenance records. Pay attention to the hours on the equipment rather than its age. Also, make sure to buy the right equipment for the job.
The costs for used recycling equipment is seasonal, with the best buys usually in December through February. Also, the used equipment business is competitive, so get quotes and information from two or three vendors.