Probably the most interesting object on my desk is the shaker bottle demonstrator for a company called FilterMag. The small, clear bottle is filled with iron shavings suspended in vegetable oil. Slap on the FilterMag product (a specially engineered rounded magnet) and shake the sample—pretty quickly, voila! You can see the shavings aligned to the magnet, stuck to the side of the bottle.
This simple but ingenious technology is the idea behind magnetic filtration. These reusable magnets, correctly applied to hydraulic filters, can be an excellent backup system to catch metal particles that are otherwise missed by the filtration system. And metal particles are amongst the most damaging to hydraulic components.
Within the tight tolerances of modern equipment, normal wear generates tiny steel particles—particles that remain suspended in the oil and hydraulic fluids that circulate through engines and machinery. The problem has been that these contaminants are so microscopically small that they pass through even the most advanced filtration systems. The oil will continue to lubricate, but laden with these all-but-invisible particles, the oil will also cause an exponential increase in additional particles—and damage. The longer the oil or hydraulic fluid circulates, the greater the damage. FilterMags have been shown to reduce particle counts by 50% or more. Studies show that kind of reduction can extend the life of hydraulic components by as much as 30%.
Magnetic filtration technology has been available for some time, but there have been some advancements over the years—most significantly, the adoption of neodymium alloy magnets. These are the strongest rare earth permanent magnets, and are used in magnetic resonance imaging systems. They have the potential to extract the greatest amount of wear-causing particles as small as 3 μm in size.
Yet for all their power, the magnets cannot deliver optimal filtration results without preventing magnetic flux—which emanates in all directions—from escaping into an engine compartment. In many cases, half of this flux is wasted in the wrong direction. Any magnetic filtration solution must compensate for this flux phenomena by shielding this wasted flux and redirecting suspended particles flowing through oil, hydraulic and/or fuel systems back into the filter where they can be trapped. When evaluating magnetic filtration technologies, be certain to investigate the efficacy of handling this flux challenge.
There are industries where reliability of vehicles and equipment is particularly critical, such as mining. One FilterMag customer calculates that a single haul truck (a true behemoth) carries a load of ore worth about $2,000 in net income. This rig is responsible for about 22 daily carries, or $44,000, every day. It’s easy to see that if you put this vehicle in the shop for maintenance and repairs, or a re-build, that’s a lot of lost income. The goal is very long intervals between servicing. That means the key is preventing the wear, tear and harm caused when lubricating fluid is not properly maintained.
A typical filter, working by itself, removes only the largest particles. It’s the small stuff, sub-20 μm, that does the most damage. And these are the contaminants that remain in circulation, propagating more particles at an exponential rate. It’s pretty ironic that the tiniest contaminants are the ones that can bring down the biggest vehicles and equipment.
FilterMag Inc.
www.filtermag.com
Filed Under: Mobile Hydraulic Tips