Aerosol dynamic processes of soot aggregates in a laminar ethene diffusion flame

Journal Article · Mon Feb 01 04:00:00 EST 1993 · Combustion and Flame; (United States)

DOI:https://doi.org/10.1016/0010-2180(93)90043-3· OSTI ID:6761962

Puri, R; Richardson, T F; Santoro, R J ^[1]; Dobbins, R A ^[2]

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1. Pennsylvania State Univ., University Park (United States)
2. Brown Univ., Providence, RI (United States)

Laser scattering/extinction tests on a coannular ethene diffusion flame were analyzed using cross sections for polydisperse aggregates. Using an improved experimental arrangement that allowed simultaneous measurement of light scattering at multiple angles, it was possible to determine the fractal dimension of the aggregates in the flame. The analysis also yields the mean-square radius of gyration, the aggregate number concentration, the average number of primary particles per aggregate, as well as the volume average of the volume-mean diameter as a function of height or residence time along the particle path of maximum soot concentration in this flame. These results lead to the conclusion that soot aerosol dynamic processes in the laminar ethene flame are partitioned into four regions. Low in the diffusion flame there is a region of particle inception that establishes the number of primary particles per unit volume that remains constant along a prescribed soot pathline. In the second region, there is sustained particle growth through the combined action of cluster-cluster aggregation (CCA) accompanied by heterogeneous reactions contributing to monomer-cluster growth. Oxidation processes occur in the third region where CCA continues. If aggregate burnout is not complete in the oxidation region, then smoke is released to the surroundings in the fourth region where reactions cease but clusters continue to grow by CCA. The experiments yield the CCA growth rate within the flame which compares favorably with the theoretical value. The similarities and differences between this data reduction and the traditional analysis based on the use of cross sections for Rayleigh spheres and Mie theory spheres is discussed.

• OSTI ID: 6761962
• Journal Information: Combustion and Flame; (United States), Journal Name: Combustion and Flame; (United States) Vol. 92:3; ISSN 0010-2180; ISSN CBFMAO
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
025000* -- Petroleum-- Combustion
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400800 -- Combustion
Pyrolysis
& High-Temperature Chemistry
AGGLOMERATION
ALKENES
CHEMICAL REACTION KINETICS
COMBUSTION KINETICS
DIFFUSION
ETHYLENE
FLUID FLOW
FLUID MECHANICS
HYDROCARBONS
INHIBITION
KINETICS
LAMINAR FLOW
LASERS
LIGHT SCATTERING
MECHANICS
ORGANIC COMPOUNDS
PARTICLE SIZE
QUANTITY RATIO
REACTION KINETICS
SCATTERING
SIZE
SOOT