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SCREENING SIZING Hybrid Screen Solves Blinding Problems MAJOR WIRE NAMES NEW DEALER Montreal-based Major Wire Industries Limited named Kirby-Smith Machinery, Inc. as its new Authorized Dealer for aggregate, asphalt and recycle operations in Eastern Kansas, Oklahoma and Northern Texas. The dealership offers all of Major Wire's screen media solutions, including the advanced technology Flex-Mat 3 Self-Cleaning Screen Media in tensioned and modular versions and OptimumWire Woven Wire. "Kirby-Smith makes customer service a top priority," said Gary Pederson, Major Wire vice president of sales. "In addition to their full staff of service personnel working with customers on-site, they also offer seminars throughout the year to help their customers stay on top of industry changes and advancements. Their dedication to providing customers with superior service and expertise fits perfectly with the valueadded programs offered by Major Wire, including on-site screening plant audits, screen maintenance seminars and our Flex-Mat 3 Results Guaranteed Program." A quarry in western Wisconsin faced an all‐ too‐common problem: they regularly ran silica sand with some clay and rock, which con‐ stantly caused blinding and plugging of their screening media. The plugging and blinding meant that operations had to shut down more often than normal for screen maintenance and cleaning – delays that also meant loss of pro‐ duction and revenue. The producer originally used wire cloth with square openings purchased from Unified Screening and Crushing. While the screens de‐ livered about 1,000 hours of wear life, the clay content of the material continued to blind over the screen. They switched to a self‐cleaning screen from a different manufacturer, only to see the wear life plunge to just 200 hours be‐ fore failure. The producer, a member of The National Stone, Sand and Gravel Association (NSSGA), reviewed the association list and decided to call in Rod Skindrud, the Unified field repre‐ sentative in the region, for his professional evaluation. Before joining Unified, Skindrud was a quarry supervisor. Most Unified field reps have previous industry experience working for quarries, equipment suppliers, foundries or other aggregate/min‐ ing‐related companies. "It's a prerequisite for the job," said Bob Kleason, Unified's director of marketing and sales. "We don't just sell prod‐ ucts. We solve customer problems. To be suc‐ cessful in our industry, nothing beats field experience. All Unified field reps know the various local materials, local processing condi‐ tions and other factors that effect wear life and throughput." Skindrud visited the Wisconsin quarry and evaluated the materials and conditions. He asked the producer what specific problems they experienced. How effective were different types of screens when processing the materi‐ als that caused blinding? How much did each screening medium actually affect throughput before and after change‐out? or develop a new type of screen media to solve the problem? Unified's mechanical engineers carefully re‐ viewed the field reports and test data. They knew that nobody knows a production prob‐ lem better than the people on the jobsite. "They take what was learned in the field," Kleason said, "and check it against our large database of field reports. We update the data‐ base regularly to stay on top of ever‐changing conditions and throughput." Kleason added, "the work on a new screening medium com‐ bines all the field data with the engineering team's own deep knowledge of screening media and design." Finding a Solution Unified engineers realized that the key to pro‐ cessing wet, sticky material was to create a vi‐ bratory screen surface. They achieved this by re‐designing a special hybrid of wire cloth and polyurethane support strips – a combination that lets each wire vibrate independently, eliminating wire‐to‐wire contact. As material falls on the screen, the wires vibrate at their own frequency. This allows material to slip through while maintaining accurate material sizing. After more development and testing, Unified's new SuperFlow screen was ready for the field. Skindrud and the Unified engineering team determined the right SuperFlow screen for the producer in western Wisconsin was a custom screen with a heavier "Tufflex" wire construc‐ tion. Today, those screens run between 2,100 and 2,800 hours before change‐out. By that time, more than a million tons of material has been processed across the screens. Customer inspection shows that, "the screens are not even broken, but we change them out as a pre‐ ventative measure." Unified Screening and Crushing, www.unifiedscreening.com Expertise in Engineering Skindrud then returned to Unified, discussed his field notes with the regional engineer and posed a challenge to Unified's engineering team: Could Unified provide the right screen 26 ROCKproducts • JULY 2013 www.rockproducts.com