Accession Number : AD0782560

Title :   Soot Concentration and Absorption Coefficient in a Low-Pressure Flame.

Descriptive Note : Technical rept.,


Personal Author(s) : Wersborg,B. L. ; Fox,L. K. ; Howard,J. B.

Report Date : JUN 1974

Pagination or Media Count : 31

Abstract : Soot concentrations at different positions through the carbon formation zone of a premixed acetylene/oxygen flat flame at 20 mm Hg were evaluated by measuring the attenuation of a laser beam passed through the flame. The required soot absorption coefficients were measured in the same optical system by replacing the flame with standard soot samples deposited on glass slides in a molecular beam sampling instrument. In comparison with soot particle concentrations measured previously under the same flame conditions using molecular beam sampling and electron microscope analysis of beam deposits, the concentrations observed here are substantially larger in the regions of particle nucleation and rapid surface growth. The difference is attributed to absorption by large hydrocarbon species whose sizes range up to that of the smallest soot particles observed under the electron microscope (about 15 A diameter or 2130 atomic mass units). (Modified author abstract)

Descriptors :   *Flames, *Combustion products, Coagulation, Absorption spectra, Concentration(Composition), Surfaces, Nucleation, Hydrocarbons

Subject Categories : Atomic and Molecular Physics and Spectroscopy
      Combustion and Ignition

Distribution Statement : APPROVED FOR PUBLIC RELEASE