Agglomeration of soot particles in diffusion flames under microgravity
Experiments have been conducted to investigate the behavior of soot particles in diffusion flames under microgravity conditions using a 490-m drop shaft (10-s microgravity duration) in Hokkaido, Japan. Flames from the combustion of paper sheets and butane jet diffusion flames are observed under microgravity. The oxygen concentration of the surroundings, the butane flow rate,and the burner diameter are varied as experimental parameters. The generated soot particles are sampled under microgravity and observed using scanning electron and transmission electron microscopes. The flames with a residual convection or forced convection are also observed to examine the influence of flow field on soot particle generation under microgravity. From these results, it is found that a number of large luminous spots appear in diffusion flames under microgravity. From the observation of TEM images, the luminous spots are the result of agglomerated soot particles and the growth of their diameters to a discernible level. The diameter of the agglomerated particles measure about 0.1 mm, 200 to 500 times as large as those generated under normal gravity. It is suggested that these large soot particles are generated in the limited areas where the conditions for the formation of these particles, such as gas velocity (residence time) and oxygen concentration, are satisfied.
- OSTI ID:
- 6535538
- Report Number(s):
- CONF-940711--
- Journal Information:
- Combustion and Flame; (United States), Journal Name: Combustion and Flame; (United States) Vol. 99:2; ISSN CBFMAO; ISSN 0010-2180
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
025000 -- Petroleum-- Combustion
09 BIOMASS FUELS
092000 -- Biomass Fuels-- Combustion-- (1990-)
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400800* -- Combustion
Pyrolysis
& High-Temperature Chemistry
AGGLOMERATION
ALKANES
BUTANE
CHEMICAL REACTION KINETICS
CHEMICAL REACTION YIELD
COMBUSTION KINETICS
ELECTRON MICROSCOPY
GRAVITATION
HYDROCARBONS
KINETICS
MICROSCOPY
ORGANIC COMPOUNDS
PAPER
PARTICLE SIZE
REACTION KINETICS
SIZE
SOOT
YIELDS