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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MAINTENANCE Improve Equipment Reliability and Reduce Costs with Clean Oil By Caren Caffrey While many companies struggle to contain costs and reduce their environmental footprint, quite a few underestimate the value found in keeping oil clean and dry. Oil is traditionally changed at recommended time intervals rather than when the key features of the lubricant, such as AW and EP additives, no longer function. Removing or reducing the primary contaminants responsible for additive consumption and oil degradation will extend the life of the lubricant and the equipment it is designed to protect. Most oil problems can be attributed to the following types of contaminants: • Particulates like dirt and wear metals generate abrasive wear and cause machine breakdowns. • Moisture/water from condensate or process conditions creates micropit ting and cavitation, which lead to spalling and fatigue wear. • Oxidation products like varnish and sludge lead to "sticking" valves and dirty vessels. 82 E&MJ; • AUGUST 2013 In a medium-loaded oil system, research shows that about 70%-80% of the particulates are below 5 microns (µm) and almost 90% of the particulates are below 10 µm in size. If the mechanical system in question has a clearance zone that is less than 10 µm, these particles get caught in the boundary zone and are slowly ground down until they are small enough to pass through the metal cracks. Elimination of these small particles through effective filtration improves machine productivity exponentially. In the real world, maintenance teams must balance proactive preventative maintenance opportunities against the constant demands of production and cost of downtime. For large mobile equipment such as a haul truck, the costs of repairing a wheel motor can be enormous, easily exceeding $250,000 per day. If needed parts are not readily available, these costs can quickly skyrocket into the millions. • Lost production: $190,000 + per day • Oil change: $3,500-$15,000 • Minor repair (seal replacement): $90,00-$130,000 • Major repair (seals, bearings, sleeves): $230,000-$260,000 • Wheel motor replacement: $650,000-$780,000 (Lead time: 1-21 days) Proactively cleaning key lubricant systems rather than simply changing oil at predetermined time intervals will reduce maintenance costs and maximize equipment productivity. The CJC Mobile Flushing Unit was specifically designed to handle the highly viscous gear oils with the very low temperatures found in the mining industry. Field tests have proven the CJC Mobile Flushing Unit will quickly clean lubricants from ISO VG 32 to ISO 680+ during routine PM service intervals. Clean oil from the heated reservoir is pumped at approximately 3.5 gpm (800 l/hr) through the gearbox (rear dif- www.e-mj.com