PADNOS, Holland, Michigan, handles ferrous and nonferrous metals, plastics, paper and electronic scrap as part of its recycling and scrap management services for industrial and commercial accounts throughout the U.S.
The company, which has been handling recyclable materials for more than 100 years, operates 24 locations across the country. Among its primary customers are foundries and mills that reuse the valuable materials processed at its sites as feedstock for new products.
The firm has made a significant investment in processes and technologies to recycle paper and plastics—and more recently, electronics—continuously building relationships with scrap dealers, logistics providers and buyers across the country. Now in its fourth generation of family management, the firm strives to leverage a century of scrap management expertise, implementing industry best practices for optimal efficiency, while maintaining the highest level of environmental stewardship.
As part of that philosophy, PADNOS is constantly developing and refining its approach to fugitive dust management, with a goal of preventing the escape of any particles that may be generated by its activities. PADNOS Purchasing Director Bruce Karger described the company’s efforts to deliver open-area dust suppression at its downtown location in Holland.
“The site is about 29 acres,” explained Karger. “We handle primarily metals at this facility, such as scrap from stamping plants and other metalworking operations, as well as peddler scrap from our smaller yards. Most of it comes in by truck, and it’s moved by front loaders and cranes, though we also have rail and barge service.”
The loaders feed a shredder and a large shear, one built by Metso Texas and one supplied by Universal. Both have integrated dust suppression capabilities, but the outflow dries fairly quickly, especially in hot weather. Subsequent handling of the shredded material inevitably creates dust, which can migrate long distances if left unchecked. With the facility surrounded by businesses and neighborhoods, PADNOS officials wanted to take proactive measures to ensure that dust would not create a nuisance for the surrounding community or create a workplace hazard.
Searching for the right design
After investigating several manufacturers of dust suppression equipment and reviewing their equipment choices, PADNOS selected a DustBoss DB-60, supplied by Peoria-Illinois-based BossTek, to deliver suppression over three processing centers, covering about three acres in all. “Other than basic material handling, the main dust-generating activities are shearing, shredding and bricking,” Karger says. “Our goal is to ensure that airborne particles don’t leave the property.”
The atomized misting unit of the DB-60 generates millions of droplets specifically sized to maximize dust suppression, and then launches them over large distances in an engineered air plume created by a powerful ducted fan.
A 25-horsepower electric motor gives the machine a reach of nearly 200 feet, allowing the oscillating unit to cover an area as large as 125,000 square feet with a virtual dust blanket. Supplied with a 20-foot mounting tower, the DB-60 was installed atop a 10-foot concrete pedestal to increase its range and aiming ability even further. The control panel, booster pump and three-way valve are located inside a shed for protection.
“We’ve used hoses and sprinklers in the past, and at times we’ve had our own water trucks on-site,” PADNOS Superintendent Tim Driesenga says. “But the suppression performance wasn’t what we had hoped for. We’ve also tried dust suppression equipment from other suppliers, but when we compared results from the machines we had to the DustBoss, the DB-60 was far more effective, clearly a higher-quality design. It does a much better job of knocking down the dust and keeping it down.”
The unit was originally supplied with four optional remote controls, giving loader operators the ability to turn the unit and the oscillation on or off at any time. The oscillation range, however, was only programmable at the panel. Although the system performed well, operators noticed an opportunity to even better serve the unique layout and workflow at the Holland plant, so they contacted BossTek to discuss some possible modifications to the system.
“We felt that we could make dust control even easier and more efficient for the operators who are moving our material,” Driesenga says. “The easier the equipment is to operate, and the more efficiency we can build into the dust management process, the more likely that the equipment will be used, and used correctly.”
During the initial meeting with BossTek, Driesenga explained that loading and unloading could take place at nearly any point within the roughly 3-acre area, and the 359-degree oscillation was key to reaching those activities. But the relatively slow oscillation speed prevented a quick rotation of the barrel to focus on an arriving truck; thus, operators had to wait for the machine to oscillate to the required spot.
"We were extremely impressed with the technical assistance [BossTek] provided in developing the concept and turning it into a working reality,” –PADNOS Purchasing Director Bruce Karger
The big question was whether the unit could be redesigned to reach any point on the oscillation arc in 30 seconds or less, and be built with the control capability into the remotes that PADNOS currently had. Adding the ability to set the arc remotely would also be a huge bonus, relieving operators from having to visit the control panel.
“The first reaction we got was, ‘We’ve never done that before,’” recalled Karger. “But no sooner was that said, then the BossTek team got busy with us to figure out exactly what features we needed and how it could be done.”
BossTek engineers decided that they could achieve the desired repositioning speed by replacing the fixed-speed oscillation motor on the device with one that turned approximately four times faster and coupling this with a variable-frequency drive (VFD). To avoid having to ship the unit back for the revisions, BossTek’s personnel performed the gear motor change-out, panel modifications and VFD installation on-site.
While maintaining all existing controls on the remotes, the technicians also added the ability to select from eight preset oscillation ranges, which could be programmed by operators from the modified panel with its touch-screen display. Finally, they added a “jog left/right” switch and a “home” button to the remotes for quick repositioning.
“With the modified remotes, we have much more versatility in aiming the DustBoss and quickly bringing it to the exact location needed at any given time,” Driesenga says. “And the oscillation arc can be changed even while the oscillator is running.”
Results from air monitoring at the PADNOS site have confirmed the machine’s effectiveness and helped the company remain in compliance with local air quality regulations.
“We recently had an inspector review our operations this past summer, and he commended us on our dust control measures,” Driesenga concluded. “The results were better than he expected.”
Added Karger, “I feel like these are the tools that enable us to do a better job of preventing dust from leaving our property. For us, it’s taking our dust management to the next level. In fact, we have plans in place for another unit.”