Soot Precursor Particles in Flames
Thermophoretic sampling was conducted in buoyancy dominated diffusion flames fueled by ethene, methane and acetylene and in the laminar ethene flame. Small polydisperse singlet particles which are more transparent to the electron beam are found at intermediate temperatures on the fuel side of the flame front in these flames. The particles form agglomerates at the flame front or in the upper regions of the flame. The microparticles conform to the description that has been provided by Wersborg et al. of similar species found in the premixed acetylene flame at low pressures which suggests that they are a common particulate precursor to carbonaceous soot in hydrocarbon flames. It is concluded that the particles are likely to be composed of polyaromatic hydrocarbon compounds, which have been found by others to be present in hydrocarbon flames, and that the precursor particles undergo annealing to form a partially graphitic soot upon exposure to elevated temperatures at the flame front.
KeywordsFlame Front Soot Particle Diffusion Flame Soot Formation Combustion Institute
Unable to display preview. Download preview PDF.
- 17.5R.J. Santoro, H.G. Semerjian: “Soot Formation In Diffusion Flames; Flow Rate, Fuel Species and Temperature Effects”, in Twentieth Symposium (International) on Combustion ( The Combustion Institute, Pittsburgh 1984 ) p. 997Google Scholar
- 17.7C.M. Megaridis, R.A. Dobbins: “Soot Aerosol Dynamics in a Laminar Ethylene Diffusion Flame”, in Twenty-Second Symposium (International) on Combustion ( The Combustion Institute, Pittsburgh 1988 ) p. 353Google Scholar
- 17.9R.A. Dobbins, R.J. Santoro, H.G. Semerjian: “Analysis of Light Scattering From Soot Using Optical Cross Sections for Aggregates”, in Twenty-Third Symposium (International) on Combustion ( The Combustion Institute, Pittsburgh 1990 ) p. 1525Google Scholar
- 17.10\R. Puri, T.F. Richardson, R.J. Santoro, R.A. Dobbins: in preparationGoogle Scholar
- 17.11B.L. Wersborg, J.B. Howard, G. C. Williams: “Physical Mechanisms in Carbon Formation in Flames”, in Fourteenth Symposium (International) on Combustion ( The Combustion Institute, Pittsburgh 1973 ) p. 929Google Scholar
- 17.12J.T. McKinnon: “Chemical and Physical Mechanisms of Soot Formation”; Ph.D. Thesis, M.I.T. (1989)Google Scholar
- 17.13A.S. Feitelberg: “The Effects of Metal Additives on Soot Formation”; Ph. D. Thesis, M.I.T. (1990)Google Scholar
- 17.14M. Frenklach, H. Wang: “Detailed Modeling of Soot Nuleation and Growth”, in Twenty-Third Symposium (International) on Combustion ( The Combustion Institute, Pittsburgh 1990 ) p. 1559Google Scholar
- 17.15J.B. Howard: “Carbon Addition and Oxidation Reactions in Heterogeneous Combustion and Soot Formation”, in Twenty-Third Symposium (International) on Combustion ( The Combustion Institute, Pittsburgh 1990 ) p. 1107Google Scholar
- 17.16H.Gg. Wagner: in Soot Formation in Combustion - an International Round Table Discussion, ed. by H.Jander, H.Gg. Wagner ( Vandenhoek und Ruprecht, Gottingen 1990 ) p. 114Google Scholar