Machinery Lubrication

Machinery Lubrication Mar Apr 2013

Machinery Lubrication magazine published by Noria Corporation

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• The surface of each ring. • The average opacity of each ring. The software was designed to be able to analyze a series of spots coming from the same oil at various stages of degradation. This possibility was created in order to carry out a follow-up of each value measured during artificial life tests and also during the engine follow-up. The new approach makes it possible to obtain results of dispersancy analysis in a numeric format. With this technique, the detection of the rings is much more precise and repeatable. Case Study #1: Thermal Qualification of an Engine Oil Before testing the new method on lubricants contaminated by biofuel, two lubricants considered internal references were tested. • RH 2010 engine oil was qualified as a high-level reference. • RL 2010 engine oil was qualified as a low-level reference (judged as "borderline"). For the evaluation of the thermal behavior of engine oil, new and pure engine oil was stressed with an accelerated aging, including a thermal stress (170 degrees C) in the presence of oxygen and an oxidation proprietary catalyst. After 72, 96, 120 and 144 hours, samples were taken. Each sample was then analyzed with the new method and instrument described previously. A spreading out of the high-level reference oil RH2010 in comparison to the borderline oil RL2010 was observed. In addition, it was noticed that opacities of the central rings were much darker. These tests carried out with the new blotter test method confirmed the respective quality level of the two engine oils. In this particular case, their capacity to disperse insoluble oxidation matter was verified. a reduction in spreading out in the presence of biofuel GOPSA10 was observed. This result becomes critical with respect to the acceptable requirements that are based over the duration of 120 hours. Conclusion Although a relevant mathematical model must still be developed, this new method will make it possible to determine the dispersancy of an oil by its capacity to disperse insoluble matter. It also is able to precisely evaluate the resistance of a new oil to disperse insoluble matter when submitted to an oxidation test and/ or thermal behavior test. In addition, it can determine the impact of pollutants such as biofuel on the dispersancy capacity of oils thanks to the precise measurement of each ring. The process and the instrument of the new method are usable in the laboratory and on engine benches or rolling vehicles for any mechanical parts lubricated with oil, such as a marine engine or a wind turbine, and for many types of oils, including industrial oils, cutting oils, etc. Specific calculation criteria for oils resulting from rolling bench or in-service vehicles can also be defined. By analyzing the measured parameters in each ring, it should be possible to determine the types of pollutants present in the oil and their implication on dispersancy. Thus, it becomes possible to have an indication on the cleanliness of the bodies and to quantify in a precise way the pollutants in oil (soot resulting from the combustion of the fuel, metal particles due to the wear and corrosion of the bodies, products resulting from the aging of oil, etc.). Case Study #2: Thermal Qualification of an Engine Oil in the Presence of Biofuel The same two qualified engine oils, the high-level reference and the borderline reference, were stressed with the aging method, but diesel B10 was added starting from 72 hours of the test. Then, the contamination level of diesel B10 was maintained to 10 percent during the remainder of the test. A reduction in spreading out and a more important opacity in the presence of biofuel GOPSA10LUB for the high-level reference oil was observed. The RH2010 oil approached the rupture limit at the end of the 144 hours, but the total result according to the criteria remained satisfactory, although the bad dispersancy in the presence of biofuel was highlighted. With this engine oil evaluated as borderline, www.machinerylubrication.com | March - April 2013 | 31

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