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The Existence of Precursor Soot in the Exhaust of Inverse Diffusion Flames



L G. Blevins, Robert A. Fletcher, Bruce A. Benner Jr, Eric B. Steel, George W. Mulholland


Knowledge of the chemical and physical structure of precursor soot is useful in the development of soot particle inception models. This paper examines the hypothesis that soot exiting an inverse flame is similar in chemical and morphological structure to (1) young precursor soot and (2) soot that exits underventilated flames. Experiments involving soot collection from the exhaust of laminar ethylene inverse diffusion flames were performed. Soot samples were analyzed for morphology, carbon-to-hydrogen ratio, organic fraction, and polycyclic aromatic hydrocarbon content. Results of these analyses prove the validity of the above hypothesis. This finding is significant because exhaust collection from the inverse flame provides an opportunity to gather large precursor soot samples without invading the flame with an intrusive probe (a necessary task when collecting precursors low in the center of a normal diffusion flame). Larger samples can then be subjected to more detailed analysis than previously possible.
Proceedings of the Combustion Institute


carbon-to-hydrogen ratio, gas chromatography/mass spectroscopy, inverse diffusion flame, laser microprobe mass spectrometer, polycyclic aromatic hydrocarbon, precursor soot, transmission electron microscopy


Blevins, L. , Fletcher, R. , Benner, B. , Steel, E. and Mulholland, G. (2002), The Existence of Precursor Soot in the Exhaust of Inverse Diffusion Flames, Proceedings of the Combustion Institute (Accessed July 18, 2024)


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Created October 1, 2002, Updated February 19, 2017