Machinery Lubrication magazine published by Noria Corporation
Issue link: https://www.e-digitaleditions.com/i/325287
Agglomeration Electric-Charge Filters Agglomeration-type filters are effective with submicron parti- cles and soluble and insoluble varnish. They can use conventional filters of almost any type. The proprietary electrical-charge component is fixed and not changed, which yields low operating costs. These types of filters offer the advantage of high flow rates for large reservoirs. They are best used as a preventive measure. Depth-Media Filters Depth-media filters can quickly remove larger, more insol- uble varnish like PANA. They are not usually affected by water content and require a relatively low upfront cost and little maintenance. These filters are best used as a removal tool for insoluble varnish. Precipitation Electric-Charge Filters Precipitation electric-charge filters are well-suited for smaller reservoirs. Like agglomeration-type filters, they are effective with submicron particles and soluble and insoluble varnish. They also have a relatively low upfront cost and are best used to remove insoluble varnish. Combining these technologies could be very beneficial, particularly the use of an agglomer- ation type of charging system with a depth-media filter to collect agglomerated varnish instead of using conventional filtration. An ideal system might consist of all three tech- nologies — an agglomerator, a precipitator and a depth-media filter for collection. Latest Trends Several recent trends may make the varnish issue a moot point. These include the phasing out of PANA-type antioxidant additives, the introduction of varnish-solubility additives that work in conjunction with electric-charge technology, the use of Group I base stocks as "boutique oil blends," and the development of submicron particle counting, which likely will lead to better ways of monitoring soft contaminant issues. In addition, original equipment manufacturers and oil companies are communicating more frequently in all-vol- unteer organizations like ASTM. ASTM's work on automatic particle counting of submicron particles less than 4 microns may offer a more credible approach for varnish measurement. It does not measure a specific color range but rather a specific size range and likely will not discriminate what is detected by the root cause of the contami- nant (color). While the proposed new standard is still in its infant stages, many hope it will overcome the problems inherent in the MPC patch. All this attention on the varnish issue has served as a reminder of how prevention is much less costly than the cure. Indeed, it is easier to keep things clean from the beginning than to clean them up after they are dirty. Most conser- vative research estimates place the relative cost savings at nearly 80 to 90 percent. In other words, it only costs about 10 to 20 percent more to implement a contaminant prevention program than it costs to remove the contami- nants after they are in the system. VArNIsh 30 May - June 2014 | www.machinerylubrication.com