VDMA

Germany 2019

Best of Germany 2014 - Mining Equipment and Mining Technology

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VDMA 36 VDMA MINING SUPPLEMENT • 2019 Bearing specialist Schaeffler recently introduced the sealed 241/1250 spherical roller bearing for high-pressure grinding roll (HPGR) applications. Designed to offer significant cost savings and boost efficiency, the ultra-large 241/1250 bearing features an out- side diameter of nearly 2 meters (m) and was specifically designed for the highest-capacity HPGRs. Previously only available in an open configuration (without seals), Schaeffler's sealed version of this massive roll-support bearing is designed to prevent the crushing materials from contaminating its internal components. In the past, miners have typically been forced to inject high quantities of grease into the bearings to prevent contamination. While necessary, this practice wastes resources and significantly in- creases a mine's preventive maintenance expenditures. By introduc- ing a sealed bearing for this challenging application, Schaeffler's innovation aimed to also increase mining productivity. The bearing's sheer mass — as evidenced by a total weight of approximately 8 metric tons (mt), including rolling elements that weigh 60 kg each — presented an engineering challenge that very few companies are able to master, even before the complex seal- ing arrangement is factored in. The outside diameter of the molded seal, which features design elements that were first developed for marine applications, measures approximately 1.4 m. The state-of-the-art sealing properties are provided by metal shields installed on both of the bearing's side faces, each of which features an optimized polymer seal that prevents the ingress of crushing material. Since the introduction in 2017, the portfolio of the sealed ver- sion for large-size spherical roller bearings has been continuously enlarged and is now successfully established in the market with a huge range of available sizes. Conveyor Equipment Headquartered in Hilden, Germany, the ZILLLER Group owns three companies that specialize in conveyor maintenance: NILOS supplies belts, industrial rubber, and all the materials needed for hot or cold vulcanizing; WAGENER Schwelm GmbH & Co. specializes in vulca- nizing presses for splicing and repairing conveyor belts; and Coal Control, which has developed a system that detects longitudinal rips in belt conveyors as well as automation technology of all kinds. One special product, the Rotocut from Wagener Schwelm was designed to improve safety of workers by reducing the noise and dust when a belt must be cut for repair purposes. Available in two different sizes, the smaller Rotocut RCM20 can cut belt thickness up to 20 mm and a Ø steel cord up to 7.5 mm (ST2500). It's manu- ally driven, with a carrying side of 9 mm max., running side 5 mm max. and a weight of 45 kg, which makes it a mobile tool to use on site. A 65-kg version of the RCE20 has an electric drive. The larger Rotocut RCE 40 is able to cut belts belt with thickness up to 40 mm and Ø steel cord up to 11 mm (ST5400) with a cutting speed of up to 1.10 m/min safely. The weight of this big machine is 165 kg. Through the NILOS campus, the company also offers courses to train technicians to become a certified specialist for vulcanizing conveyor belt. Positive Displacement Pumps The Pniówek coal processing plant in Poland operates nine chamber filter presses with 570 m 3 of filtration area each. Before moderniza- tion, two centrifugal pumps were used two feed the press and they were consuming 560,000 kWh/year of energy. Added to this were repair costs of approximately 27,000 EUR annually. The plant operator knew there had to be a better way. PRO- INDUSTRY Sp. z o.o. Sp.k launched a project to modernize this sys- tem at the beginning of 2013. An ABEL positive displacement pump was added to the filter press in parallel with the existing centrifu- gal pump. This arrangement sought to improve overall efficiency by allowing the centrifugal pump to work within its optimal flow and pressure curve while shifting the higher-pressure duty to the ABEL PD pump. The ABEL HMD-G-50-0500 was selected for its abra- sion-resistant piston-diaphragm design and its energy efficiency. It pumps 50 m 3 /h at a pressure of 15 bar. Sealed Spherical Roller Bearings for HPGRs The ultra-large 241/1250 sealed bearing was designed specifically for HPGR applications. The Rotocut RCM20 can cut belt thickness up to 20 mm and a Ø steel cord up to 7.5 mm (ST2500).

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