RRT Breaks Ground on Minnesota Plant’s Expansion

RRT Design & Construction, a design, engineering, construction and consulting firm based in Melville, N.Y., has broken ground on a mixed waste material recovery facility (MRF) in Perham, Minn. According to RRT, the 40-tons-per-hour preprocessing system will process mixed waste and recover ferrous and nonferrous metals, fiber, noncombustible materials, glass and fines prior to the remaining waste being converted to energy at the facility.

The owner of the facility, the Prairie Lakes Municipal Solid Waste Authority, chose RRT to design the project following a competitive bidding process. The expansion project is part of the authority’s plan to increase throughput, recover recyclables and improve the facility’s efficiency and energy output.

The company says the new  MRF will improve the characteristics of the incoming solid waste by removing noncombustibles and undesirable waste before burning it in the plant’s combustors, reducing the overall costs of the waste-to-energy plant and increasing the overall capacity of the facility. Additionally, the MRF has been designed to recover recyclables from the incoming MSW, which reduces the amount of ash sent to the landfill and also generates revenue from the sale of recyclables.

When completed, the waste processing capacity of the facility will increase from 116 tons per day to 220 tons per day.

RRT’s scope of service includes the engineering, design, equipment supply, mechanical installation, field wiring, startup, commissioning and acceptance testing for the processing system. The system includes heavy-duty apron feed conveyors, sort platforms, an 8-foot diameter rotary trommel, two overhead belt magnets, an eddy current separator, belt conveyors, two balers, a fines removal and cleanup system, a stationary compactor, access platforms and support steel. RRT also is providing an electrical control system including motor starters, variable speed drives and dual touch screens for system control and monitoring.

Mike Hanan, the authority’s director of solid waste, says, “With the completion of the building to house the MRF, we are excited to have the RRT construction and construction management teams on site. We look forward to the successful commissioning and testing of the recovery systems they have designed.”

Nathiel Egosi, president of RRT, says, “This system will be another successful example of RRT’s unique abilities and expertise to integrate waste pre-processing for materials recovery and feedstock preparation with various downstream technologies including those for energy recovery, composting, biofuel production and other conversion approaches.”