Optical sorters and robotic sorters may work in two different areas of an MRF. For heavy volumes of a few related commodities (i.e., plastic containers) the optical sorters would be located closer to the front end of the MRF, potentially following an initial separation of light materials versus heavy materials or two-dimensional items such as fiber and paper from three-dimensional items (i.e., containers) by other equipment such as a screen or drum.
In general, a robotic sorter would likely perform better anywhere in the MRF where there is some presorting to spread material evenly across the belt and remove oversize and bulky material, or two-dimensional material like paper and foil, that can obscure the targeted materials. An MRF’s control systems are typically upgraded when optics or robotics are installed to provide the operator more local control of all sorting equipment on the line, more flexibility to address waste stream changes, and simpler control interfaces.
Read up on system information via trade publications; inquire about system performance with other operators; and talk with experienced consultants and vendors. These options will help you narrow down the best option for a facility’s needs. This same information can then be used as a resource when vetting providers.
Allow companies to come into your facility and make an initial assessment, review data you may have on material volume, material changes, and percent recovery and residue. Then request a written report. That report should include: feasibility of employing the machine(s); expected tangible improvements (i.e., rate of recovery, reduction of residue, removal of additional targeted material(s), etc.; any other modifications needed to your system to allow the new equipment to perform properly, a budget cost estimate or range, and estimated operating costs.
Send a representative waste stream sample to potential vendors and have the sample run through the vendor’s test facilities to gauge the equipment’s effectiveness. Operators should visit facilities currently running the equipment under consideration for purchase to see how it operates in person. If visiting a site isn’t possible, review a site’s system layout and analyze its efficiency results.
A fire at your transfer station or MRF can cause significant downtime, lost revenue, and added cost to restore the damaged equipment and building components. The fire department can tear a metal building apart just fighting the fire. Fires can also trigger negative publicity and could result in injury or even loss of life. Even with automatic sprinkler systems in place, fires can spread quickly. Traditional fire sprinklers are designed to protect the building from completely burning down. However, in most solid waste processing facilities, they are mounted relatively high in the building. Placement can result in significantly delayed response times to react to a fire which has time to grow and propagate. The delay can result in significant damage to structural elements, insulation, lighting, electrical, roof, and wall panels.
International Fire Protection recently published an article by Ryan Fogelman suggesting an investment in more effective fire technology safety systems to prevent fire incidents rather than mitigating the damage. The author’s solution is using automated detection of excessive heat using military grade thermal detection to pinpoint the exact location, with automated emergency alerts, remote human verification, and remotely controlled coolants to contain the threat of fire. These are all innovative solutions and certainly seem logical to help MRFs, transfer stations, and composting operations minimize the chance of an expensive emergency that could shut down operations.
Now we face the dilemma of how public agencies and businesses can afford the new or improved technology.
SCS Engineers believes that preventative strategies and designs are superior and in the long term are safer and less costly. For example, system costs typically include the monthly 24/7 monitoring and operation and set up for multi-year periods (e.g., ten years). At one MRF that experienced a fire, SCS Engineers estimated the cost to install, monitor, and maintain a 24/7 fire suppression system for the 10-year period was less than the cost of the single fire incident. Operators and owners are challenged with a business problem that requires integrating specialized engineering and technology expertise with financial expertise to create operational efficiencies.
When estimating the cost of new technologies to mitigate emergencies and increase safety, the financial considerations are paramount. Elected officials, public works directors, private sector waste management decision-makers and public utilities must operate efficiently while providing critical community services, and maintain existing service levels. They must do so while keeping rates, fees, taxes, and assessments as low as possible for the residents of a community.
Environmentally sustainable solutions must be economically feasible to achieve consensus by constituents and shareholders.
SCS Management Services™ supports a comprehensive approach to environmental solutions as described in International Fire Protection, by providing financial experts who work in combination with our engineering and technology consultants to design solutions that support MRFs, transfer stations, and composting operations planning for long-term economic and financial sustainability.
Material recovery facilities (MRFs) are seeing many challenges that directly impact operations. Some of these challenges include: new recycled material quality standards from China, the ratcheting up of voluntary and mandatory local and state recycling goals, lower tolerance for worker injury, increasing volumes and a changing waste stream, disposal bans on organics in landfills, and high demand from emerging energy
markets for organics.
MRFs equipped with the latest technologies are able to meet tightening standards for traditional quality recycled materials and some are also starting to provide a separate, clean organics stream for downstream alternative energy projects. Many MRF operators are now benefitting from these new technologies, with increased throughput and quality of end product.
The article by Bruce Clark and Mike Kalish of SCS, provides an overview of the latest developments in MRF processing equipment systems that are helping owners and operators meet these challenges and at the same time helping maintain a healthy bottom line.
Related articles, case studies, and services.
Taken as a whole, mixed MRFs have operated well since their reincarnation in the early 1990s and continued refinement through today. The sorting technology, which has been evolving for the last 25 years, has been proven to work and is reliable. Complete, pre-engineered integrated systems have been available now for years from a growing selection of established companies dedicated to the solid waste industry that can provide planning, engineering, manufacturing, controls, and startup, whether for new facilities, or retrofits of existing older facilities.
With that said, the following conclusions are offered for consideration:
Contact the authors: Bruce Clark and Marc Rogoff
