Routine maintenance and periodic adjustments could help optimize optical sorters operating in material recovery facilities.

With increasing age and hours of operation, the performance of optical sorters can start declining. General lack of cleaning and maintenance as well as the ever-changing composition of input material can exacerbate performance challenges.

During the early days of startup, commissioning and break in, new optical sorters often operate at peak performance. The challenge for operators is to keep them sorting at that level consistently day in and day out without any long-term deterioration or fluctuations over the course of the day, or even during different seasons.

To keep optical sorters working at peak performance, it is important to perform standard maintenance. Also, changing material streams might require making adjustments. These tasks are important for older (5 to 15 years old) and newer (less than 5 years old) optical sorters. Proper maintenance is necessary for optical sorters in all material recovery facility (MRF) applications, whether they are sorting plastics by resin and color, positively or negatively sorting newspaper and mixed paper or working on the residue line.

Keeping all relevant areas of the optical sorter clean and mechanically maintained will have the biggest impact on uptime and performance. This includes monitoring and, if required, adjusting the tracking of the high-speed acceleration belt, its bearings and areas around and below the return idlers, tail and head pulleys. The splitter roller inside the catcher hood as well as the air valve/nozzle assembly are spots where materials can build up over time, as well. Keeping those areas clean and easily accessible to maintenance personnel will reduce the risk of jams.

The halogen lamps that illuminate the sensing zone have a limited lifetime and must be replaced eventually. On older machines, manual monitoring of the light intensity might be required. Newer units have the capability to alert the operator when lamps should be replaced. While some optical sorters available in the marketplace will keep sorting when halogen bulbs have burned out, they will do so at reduced efficiency.

Especially during rain and snow events, the air ejectors will generate mist and liquid splatter that will settle over time on the glass surfaces that cover the halogen light assemblies as well as the sensor itself. Keeping those surfaces as clean and transparent as possible will ensure the maximum amount of light reaches the near-infrared (NIR) color spectrometers.

In the summer, air conditioning units help to keep the sensor housings as well as the operator touch-screen control panel from overheating. The dust filters for those units need to be checked, cleaned and possibly replaced on a regular basis. Extended exposure to high temperatures is a sure way to shorten the lifetime of the internal electronics.

An important aspect to increase the longevity of optical sorters is providing ultraclean compressed air that is free of moisture, oil and dust. Monitor the air quality coming from the compressor on a regular basis, otherwise the internal valve mechanisms could fail, causing the valves to remain in the open or closed position.

Testing the functionality of each air valve on a regular basis is crucial to ensuring optimum sorting performance. An 80-inch-wide, single-eject optical sorter normally uses 80 valves. If just four valves are not functional, that means 5 percent of the machine width is not performing at all, causing recovery of the targeted commodities to decline.

Basic monitoring of sensor performance and the status of internal optical and electronic components is becoming more automated and self-reported through optional push notifications, making it easier for the operator to monitor what is happening on each sorter in the facility in real time and what, if any, actions should be taken.

For example, while older units needed to be manually calibrated on a regular, sometimes weekly, basis, the latest generation of optical sorting technology can virtually eliminate this task using internal calibration routines and algorithms that can compensate for changes in the immediate environment of the machine, mostly temperature, over the course of a day.

The amount of operational and material composition data generated by the latest generation of optical sorters sometimes can be overwhelming. Advanced statistics and data analyses tools are readily available to monitor performance parameters. Integrating data generated by optical sorters throughout the MRF into the main programmable logic controller (PLC) or supervisory control and data acquisition (SCADA) system facilitates monitoring groups of machines and adjusting mechanical separation equipment as well as optical sorters. Data from other sensors installed throughout the plant that monitor conveyor speeds, disc screen angles and vacuum system air speeds also can be monitored in this way.

Sometimes, monitoring and maintenance are simply not enough to maintain the performance of optical sorters. Visit www.RecyclingToday.com/best-practices-optical-sorter-maintenance for an online sidebar about retrofits on this equipment.

Like any computer system, optical sorter libraries, databases and parameter settings should be backed up on a regular basis and in accordance with a company’s information technology (IT) policies after changes have been made by the operator.

If required, all these described tasks can be outsourced to the optical sorter vendor to ensure nothing falls through the cracks. Nowadays, remote access and support via wireless or Ethernet connection makes this easy and affordable.

For customers who require additional assistance, trained service technicians can conduct preventive maintenance visits and machine audits and provide additional operator training on-site.

It seems that the only constant for MRF operators is the ever-changing composition of incoming material. With a declining volume of newspaper and a higher percentage of cardboard, the optical sorters that perform quality control of the fiber streams might have to be constantly monitored and adjusted. They can be made more or less sensitive to certain prohibitives or outthrows with the touch of a few buttons in the latest machines.

On the container side, the increase in full-sleeve bottles featuring a wide variety of label resins have made it necessary to adjust optical sorters accordingly. The reference library containing the different material and color categories should be updated to maximize recovery of plastic containers in general and PET containers in particular.

On older units, sometimes the only way to perform this work is by using a trained technician on-site; however, the newer generation of optical sorters can be accessed remotely by factory-trained staff, and reference library and parameter settings can be updated more easily and quickly, requiring minimal support by on-site staff.

These guidelines should assist MRF operators in getting their optical sorters back up to speed and ensure they perform at their peak for a long time to come.

This article originally appeared in the February issue of Recycling Today and the May/June issue of Waste Today. Felix Hottenstein is a sales director at MSS Inc., a division of San Diego-based CP Group. He coordinates all sales and marketing activities at the company and can be contacted at hotrock@mssoptical.com.

The residential collection company represents Capital Waste’s third add-on acquisition.

Capital Waste Services (CWS) LLC, Columbia, South Carolina, a portfolio company of Kinderhook Industries LLC, has announced the acquisition of Superior Sanitation Inc., a Camden, South Carolina-based residential collection company servicing 1,700 subscription customers in Kershaw County. 

“Having owned the business for 36 years, we are excited to sell to a company that prioritizes customer service,” says Denise Dunlap, owner of Superior Sanitation. “We know Matt [Parker, CEO of CWS], and his team will keep our customers satisfied as CWS expands its reach into Kershaw County.”

Superior Sanitation represents Capital Waste’s third add-on acquisition and Kinderhook’s 49th environmental services transaction since inception.

“Superior Sanitation expands our residential collection service coverage into a new county," says Parker. "We are excited to add another operating hub for our growing company as our sales team continues to ramp up marketing efforts across South Carolina.” 

“We are excited to further invest in the Capital Waste platform, growing the company’s regional presence. With additional investment in Superior’s fleet and equipment, we will continue to provide the best service to our growing customer base,” says Rob Michalik, managing director of Kinderhook.

Financing for the transaction was provided by Comerica Bank, Dallas.

The company acquired Stemco’s Motor Wheel brake drum and Crewson business segments.

Hendrickson USA LLC, Woodridge, Illinois, has acquired the Stemco Motor Wheel brake drum and Crewson brake adjuster brands from Stemco, a specialized truck equipment manufacturing company, and its parent company EnPro Industries. 

The business segments will operate as a division of Hendrickson Truck Commercial Vehicle Systems.  The Motor Wheel & Crewson names will be kept and used as product names going forward.

“This acquisition will provide a platform for Hendrickson to advance our lightweight drum brake system performance and provide components that will complement our existing product portfolio. We look forward to working with our new associates and strengthening our business ultimately serving the commercial truck and trailer industry,” says Gary Gerstenslager, president and chief executive officer Hendrickson.

“After announcing the exit of Stemco’s Motor Wheel brake drum and Crewson brake adjuster brands on June 25th, we were pleased to receive an offer from Hendrickson to purchase the assets and to continue operating the business. This transaction represents a positive outcome for all stakeholders as it preserves the jobs of our workforce and mitigates customer disruptions while providing EnPro’s shareholders a fair valuation for the assets of the business,” says Marvin Riley, president and chief executive officer of EnPro.

Hendrickson, a Boler company, is a global manufacturer and supplier of medium- and heavy-duty mechanical, elastomeric and air suspensions; integrated and nonintegrated axle and brakes systems; tire pressure control systems; auxiliary lift axles systems; parabolic and multileaf springs; stabilizers; and bumper and trim components to the global commercial transportation industry. 

The proposed facility would be an addition to the Ramsey/Washington Recycling & Energy Center, enabling it to pull food scraps out of the waste stream for the first time.

The Ramsey/Washington Recycling & Energy Center in Newport, Minnesota, is about to take a $43 million dive into organics recycling, reports the Twin Cities Pioneer Press.

The addition to the center would enable it to pull food scraps out of the waste stream for the first time. According to a proposal, the project would increase recycling, decrease the amount of garbage being burned and reduce material sent to landfills.

“The purpose here is to get more value out of waste,” Zack Hansen, Ramsey County’s Environmental Health director, told the Pioneer Press.

The plan was submitted to the Newport Planning Commission at its Aug. 13 meeting. It calls for a 40-foot-tall addition to the existing facility.

The proposal would bring the public cost of the center to $82 million — $24 million to buy it in 2016, $15 million in improvement projects, and $43 million the new organic-waste expansion. The upgrade is necessary to handle the anticipated surge of organic waste, said Hansen.

Officials hope to kick off the Durable Compost Bag program, in which customers would put food scraps into plastic bags and toss them into the garbage. At the plant — in the new Durable Compost Bags Addition — those bags would be sorted out, and the organic material used to make mulch.

The cost of that program and the expansion would cost an average of $10 per customer per year, said Hansen. The bags would be free, and participation voluntary.

Washington and Ramsey counties are asking the state Legislature to pay for half of the $43 million price tag. If approved, the project could break ground next spring.

The facility now handles all household garbage from Washington and Ramsey counties — 450,000 tons per year. About 350,000 tons are burned in incinerators to generate electricity, and 15,000 tons are recycled.

The rest is material that can’t be recycled, including mattresses and furniture. Most of that is taken to landfills.

Petrochemical company says it will convert its San Francisco area refinery to process used cooking oil and virgin soybean oil.

Houston-based energy and petrochemical company Phillips 66 has announced it plans to reconfigure its San Francisco Refinery in Rodeo, California, to produce fuels made not from crude oil, but instead used cooking fat, oil and grease (FOG) and virgin soybean oil.

The Phillips 66 Rodeo Renewed project will be able to produce 680 million gallons annually of what the company calls renewable diesel, renewable gasoline, and sustainable jet fuel.

“Phillips 66 is taking a significant step with Rodeo Renewed to support demand for renewable fuels and help California meet its low carbon objectives,” says Greg Garland, chairman and CEO of Phillips 66. “We believe the world will require a mix of fuels to meet the growing need for affordable energy, and the renewable fuels from Rodeo Renewed will be an important part of that mix.”

If approved by Contra Costa County officials and the Bay Area Air Quality Management District, the alternative fuels production is expected to begin in early 2024. Once reconfigured, the plant will no longer transport or process crude oil, according to Phillips 66.

The project would involve building pre-treatment units and then repurposing existing hydrocracking units to enable production of renewable fuels. The plant will use its “flexible logistics infrastructure to bring in cooking oil, fats, greases and soybean oils from global sources and supply renewable fuels to the California market,” adds the firm.

The company did not disclose what percentage of the alternative refinery’s feedstock may consist of collected, spent FOG feedstock.

Adds Phillips 66, “This capital efficient investment is expected to deliver strong returns through the sale of high value products while lowering the plant’s operating costs.”