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o p e r at i n g i d e a s Conveyor Component Upgrades Boost Uptime & Safety BY CAROL WASSON Whether it's coal mining or power plant applications, material handling systems are integral to overall efficiency. Rather than merely moving material from point A to point B, today's optimum conveyor performance must meet a myriad of standards—from ensuring specified flow rates, to achieving operational goals of minimizing vibration, noise, and belt wear and tear—while maximizing plant capacities and uptime. Today's maintenance teams are finding that consistently meeting the latter requirements via existing conveyor systems can be as simple as undergoing a few strategic component upgrades. A current example involves looking beyond the traditional or standard wing pulley designs to the use of the new V-shaped wing pulley—an upgrade that significantly boosts uptime and safety initiatives. The Five Star mine in southern Indiana has replaced traditional pulleys with Chevron Wing Pulleys, manufactured by Superior Industries. According to Randy Smith, maintenance planner for the mine, the new V-shaped pulleys are replacing plain steel flat face pulleys or rubber lag pulleys in multiple locations that include tail, gravity take-up, bend and snub functions. "The main reason we wanted them— especially on the bend rollers and on the tail—is that they are self cleaning and this prevents ice buildup on the pulley face in the wintertime," said Smith. He explains that the V-shaped wings deflect material out and away. "Ice buildup can cause severe belt damage or mistracking—and ice buildup is even a problem with rubber lag pulleys. There will always be some moisture retention on a belt, especially on a bend roller, as it is contacting the top side of the belt. You can't get that 100% clean, and that ice just keeps building up. With the Chevron pulleys we have eliminated any ice buildup, and we've extended the life of our belts while minimizing any downtime," he said. 62 www.coalage.com The Chevron Wing Pulley directs material away while at the same time maintains continuous contact reducing noise. A side profile shows the difference between the Chevron Wing Pulley (left) and a standard wing pulley. A major power plant in western Pennsylvania installed the Chevron Wing Pulley on a main belt line. Group Supervisor Clyde Hopkins said they had heard of the successful operation of the new V-shaped pulley at another power plant facility. "We decided to replace a failing drum pulley on our main yard belt with the Chevron pulley," Hopkins said. This conveyor system is at the center of their operation and distributes coal to the cleaning plant and back to the main belt line that feeds the plant. Past component failures on this main belt caused costly downtime and major headaches for the crew as they had to fire up several smaller conveyors to continue to feed the plant. So the failing drum pulley was replaced with a Chevron Wing Pulley sized at 36- x 51-in. and engineered with five 7/16-in. bushings within the shaft. "We're very pleased with the performance of this pulley," Hopkins said. "First, it's a self-cleaning component, and that makes the belt track really well because it doesn't allow material to lodge between the belt and the drum itself," he April 2013