Laser particle sizing of diesel soots in two formulated oils after different engine tests

Abstract

Soots of four types were extracted from two diferent formulated diesel oils, namely oil 'A ', a 15W40, and oil 'B', a 20W40, after engine (50 h) and tribological (20 h + 20 h) tests. The soots were dispersed into four diferent model solvents and base oils, and analysed by Photon Correlation Technique.In a first study, soot particle size measurements were conducted after dilution in n-heptane, Kerdane solvent, 60N and 130N base oils. The influences of engine running-time and solvent nature have been particularly considered. The second study has been devoted to the aggregation kinetic of soots in these solvents.These data are important for a better understanding of soot dispersion stability and the rheology of used oils in diesel engines.Keywords diesel, soots, Photon Correlation Technique, laser particle sizing, dynamic light scattering lNTRODUCTDN In Europe, diesel engines are increasingly popular for passenger cars because of fuel economy and tax advantages; moreover the diesel engine is the prime mover for industrial vehicles, in both Europe and the rest of the world. The problem is that even modern diesel engines produce nitrogen oxide, other noxious gases, and a lot of soot. The black carbonaceous particles of soot coming from

Extended drain intervals for crankcase lubricants

“…The last two items in particular directly contribute to higher contamination levels in the lubricant, particularly soot content. The size of primary soot particles is in the order of 20-30 nm, but these primary particles rapidly fuse together to form larger particles in the order of 0.2-0.3µm (Kawamura et al, 1987;Constans et al, 1994;Sun et al, 1991;Bardasz et al, 1995). General opinion seems to indicate that the smaller particles are primarily responsible for oil thickening, whereas the larger agglomerates are responsible for wear taking place.…”