Coagulation of Aerosols With Broad Initial Size Distributions.
Coagulation of Aerosols With Broad Initial Size
Mulholland, G. W.; Lee, T. G.; Baum, H. R.
U.S./Japan Government Cooperative Program on Natural
Resources (UJNR). Panel on Fire Research and Safety.
Volume 6. Fire Detection. October 19-22, 1976, Tokyo,
Japan, 1-49 pp, 1976.
Journal of Colloid and Interface Science, Vol. 62, No.
3, 406-420, 1977.
fire detection; fire research; fire safety; size
distributions; aerosols; coagulation; particle size;
The effect of coagulation on an aerosol with a broad
initial size distribution was calculated analytically
for large and small particle sizes for arbitrary time
with the assumption of a constant coagulation collision
frequency. It was found for the class of algebraic
initial distributions that in general there is no
self-preserving size distribution though for the special
case of a Junge like algebraic size distribution there
is a quasi self-preserving form. The calculation also
demonstrates that coagulation alone leads to dynamic
equilibrium for large particle size without the need of
additional physical processes such as particle
sedimentation. The relevance of the calculations to
real aerosols was tested by measuring the size
distribution of smoke generated from smoldering "punk"
and flaming alpha-cellulose. The size distributions of
both smoke aerosols are not only self-preserving but
also are very similar. there is quantitative agreement
between the measured size distributions and the
calculated quasi self-preserving form.