Soot particle measurements in diffusion flames

✍ Scribed by R.J. Santoro; H.G. Semerjian; R.A. Dobbins

• Publisher: Elsevier Science
• Year: 1983
• Tongue: English
• Weight: 998 KB
• Volume: 51
• Category: Article
• ISSN: 0010-2180
• DOI: 10.1016/0010-2180(83)90099-8

✦ Synopsis

The formation and growth of soot particles in a coannular diffusion flame have been studied using a laser extinction/ scattering technique for particle size measurement. Measurements have been obtained with ethene as the fuel for various fuel flow rates. The results reveal that the flame can be broadly divided into two regions. The first is characterized as a region of growth where soot formation processes dominate, while in the second region oxidation processes are dominant. Measurements show that soot is first observed to form low in the flame in an annular region inside the main reaction zone. At higher locations this annular region widens until the entire flame is observed to contain particles. The spatial distributions of particle volume fraction, mean particle size, and particle number concentration are mapped throughout the flame using the Rayleigh theory for the scattering of light by absorbing particles. Measurements of depolarized scattered light and fluorescence have also been obtained and indicate a correlation between the species responsible for these processes and soot growth. Results indicate that the particle formation region obeys closely the Burke-Schumann scaling for flow rate dependence, whereas substantial differences occur in the oxidation region. Measurements have also been obtained using ethane as the fuel for an initial comparison of fuel structure effects.