Engineering & Mining Journal

JUN 2014

Engineering and Mining Journal - Whether the market is copper, gold, nickel, iron ore, lead/zinc, PGM, diamonds or other commodities, E&MJ takes the lead in projecting trends, following development and reporting on the most efficient operating pr

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66 E&MJ; • JUNE 2014 www.e-mj.com COMPANY PROFILE-PAID ADVERTISEMENT The Hilliard Corp. was founded in 1905 in Elmira, New York, by William J. Hilliard. Hilliard held the patent for the lever friction clutch that was used to connect and disconnect tools in machine shops to an auxiliary power source incorporating over- head belts and pulleys. This product remained the primary source of revenue for the company until the mid-920s when machine tools began to be built with electric motors built into them, eliminating the need for connection to auxiliary power. Needing a new product to promote, Hilliard looked toward the fluid filtration business. In 1925, they secured a contract with General Electric to manufacture and sell its Oil Reclaiming Machine. These machines were used to take dirty, used crankcase oil and restore it to like new oil. This new partnership marked the beginnings of the HILCO brand name of fluid filtra- tion products. The HILCO line has grown to include valves, fil- ter housings, coalescer separators and filter cartridges, all still manufactured at the Elmira, New York, facility. In 1965, Hilliard began a partnership with Twiflex of Twickenham, England, to work together on a heavy-duty cen- trifugal clutch design. That partnership has lasted to this date, with Hilliard being the United States distributor for Twiflex brakes and braking systems. These brakes are supplied for many types of applications, but primarily within the mining industry. Hilliard has also developed an intelligent braking sys- tem under the trademarked name BrakeBoss. Hilliard recently commissioned a BrakeBoss Brake Con- trol System on a new overland conveyor at Brown's Creek Complex, Rupert, West Virginia. The mine is owned and operat- ed by Greenbrier Smokeless Coal Mining LLC, Pittsburgh, Pennsylvania, USA. The 400 horsepower conveyor transport clean coal at a rate of 800 tons per hour down a steep rugged mountainside. The belt drops 468 ft over a length of 4,035 ft at an average decline angle of 6.7°. The conveyor profile features both concave and convex ver- tical curves. These curves create design challenges for extend- ed belt life. A quick start causes the belt to lift off the idlers in the trough if the belt is empty. A soft start is required to mini- mize this effect. The BrakeBoss system consists of a PLC-based hydraulic power unit and spring-applied hydraulic release caliper disk brakes. A PID loop continuously monitors belt speed and adjust brake pressure through a proportional relieve valve accordingly to match predetermined start and stop profiles. The brake system holds back the main drive from accelerat- ing too fast by slipping through the high-speed fluid coupling, providing soft start to the belt. The break system also controls the rate of deceleration during an emergency stop, preventing belt tension spikes or counterweight bounce. This produces smooth consistent stops independent of conveyor load. On-board fault diagnostics with alarms interface with main conveyor PLC via Ethernet connection. Start and stop parame- ters can be changed on the full color HMI touch screen. A UPS provides up to 5 minutes of emergency power to safely bring the conveyor to rest during a power outage. The system is fully enclosed in a NEMA 12 cabinet providing protection from the harsh conditions of a mine. Friction materials commonly used in brakes can vary in coef- ficient of friction by more than 50%. Factors that affect this value include oil/grease contamination, corrosion, rain, snow and ice. The BrakeBoss will automatically adjust the braking force to achieve the desired torque to stop the conveyor in a controlled manor. The BrakeBoss can easily be customized for other applica- tions including tension maintenance and multiple start and stop profiles. The Hilliard Corporation EMJ_pg64-71_EMJ_pg64-71 6/3/14 4:20 PM Page 66

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