In situ measurements of oxide particles in boron-containing diffusion flames

Journal Article · Wed Feb 01 00:00:00 EST 1989 · Combust. Flame; (United States)

DOI:https://doi.org/10.1016/0010-2180(89)90096-5· OSTI ID:6253408

Turns, S R; Funari, M J; Khan, A

Particulate matter in axisymmetric laminar diffusion flames produced by burning mixtures of either CO and trimethylborate (TMB) or CH/sub 4/ and TMB with air were investigated using laser light-scattering techniques. Boron oxide particle sizes and number densities were determined at various heights in the flames using polarization ratio and relative intensity measurements, respectively. In the CO/TMB flames, two distinct particle-laden regions were found. The first region was located on the rich side of the luminous flame zone and initially appeared as a narrow annulus, which grew in width downstream until the particles filled the core. A second thin annular zone appeared on the air side of the flame zone, starting approximately at the height of the luminous green flame tip and continuing to grow downstream. Particle sizes did not vary significantly with location in the flames, with diameters of approximately 0.09 and 0.15 ..mu..m in the 95% CO/5% TMB and 90% CO/10% TMB flames, respectively. Corresponding peak number densities were approximately 1.5 X 10/sup 10/ and 6 X 10/sup 9/ cm/sup -3/. The CH/sub 4//TMB flames were considerably different than the CO/TMB flames. The presence of significant quantities of water vapor presumably contributed to the formation of HBO/sub 2/(g) in favor of condensed-phase B/sub 2/O/sub 3/. At locations where oxide particles did form, they were closer to the flame centerline than the soot-containing regions. Computations of equilibrium yields of condensed-phase oxide were in qualitative agreement with the experimental results.

• Research Organization: Dept. of Mechanical Engineering, The Pennsylvania State Univ., University Park, PA (US)
• OSTI ID: 6253408
• Journal Information: Combust. Flame; (United States), Vol. 75:2
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
BORON OXIDES
FLAMES
PARTICLE SIZE
CARBON MONOXIDE
METHANE
BORATES
COMBUSTION PROPERTIES
EXPERIMENTAL DATA
LAMINAR FLOW
ON-LINE MEASUREMENT SYSTEMS
POLARIZATION
WATER VAPOR
ALKANES
BORON COMPOUNDS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
DATA
FLUID FLOW
FLUIDS
GASES
HYDROCARBONS
INFORMATION
NUMERICAL DATA
ON-LINE SYSTEMS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
SIZE
VAPORS
400800* - Combustion
Pyrolysis
& High-Temperature Chemistry