For heavy-duty diesel engines, the current tightening in exhaust gas legislation is the driving force for new developments of oil separators from blow by gases. The most potential maintenance-free solution for this challenge is the disc stack centrifuge. A disc stack centrifuge basically consists of a rotating stack of closely spaced conical discs. All parts of the centrifuge are in rotation. Blow by gas charged with fine droplets of oil is introduced at the inlet of the centrifuge. In the outer annulus, the total flow rate is divided into several partial gap flow rates. Droplets settle due to the high centrifugal acceleration at the lower surface of the upper cone. Deposited droplets create a film of oil which slides outwards because of the centrifugal force. The cleaned gas is collected in the inner annulus and leaves the separator at the outlet. As industrial disc stack centrifuges have different sizes and running conditions than the one for automotive applications, scale down to automotive dimensions is not completely possible with existing equations. Flow behaviour, the separation efficiency and the grade efficiency were calculated by CFD for a wide operation range of those oil mist separators. The numerical results were compared to experimental results. The mathematical model is presented in this paper. The numerical calculations of the flow field were carried out by the finite-volume method using the commercial CFD-code 'FLUENT'. Results of the CFD simulation are discussed. The model reduction is outlined (separation efficiency, flow distribution and pressure drop). At last numerical and experimental results are presented.
Design, flow behaviour and separation efficiency of a disc stack centrifuge - an innovative, high efficient oil mist separator for automobiles
Innovativer, hocheffizienter Ölnebelabscheider für Automotive-Anwendungen
2004
16 Seiten, 11 Bilder, 1 Tabelle, 14 Quellen
Conference paper
English
Automotive engineering | 2004
|British Library Conference Proceedings | 2004
|British Library Conference Proceedings | 2004
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