Smoke Production and Properties.
Smoke Production and Properties.
(951 K)
Mulholland, G. W.
NFPA SFPE 95; LC Card Number 95-68247;
SFPE Handbook of Fire Protection Engineering. 2nd
Edition. Section 2. Chapter 15, National Fire
Protection Assoc., Quincy, MA, DiNenno, P. J.; Beyler,
C. L.; Custer, R. L. P.; Walton, W. D., Editor(s),
2/217-227 p., 1995.
Keywords:
fire protection; fire protection engineering; smoke
production; size distribution; visibility; smoke
detection; wood; plastics; particle size; equations;
mass optical density
Abstract:
The term "smoke" is defined in this chapter as the smoke
aerosol or condensed phase component of the products of
combustion. This differs from the American Society for
Testing and Materials (ASTM) definition of smoke, which
includes the evolved gases as well. Smoke aerosols,
vary widely in appearance and structure, from light
colored, for droplets produced during smoldering
combustion and fuel pyrolysis, to black, for solid,
carbonaceous particulate or soot produced during flaming
combustion. A large fraction of the radiant energy
emitted from a fire results from the blackbody emission
from the soot in the flame. The subject of radiant heat
transfer is of such importance that it is treated in a
separate chapter. This chapter focuses on smoke
aerosols outside the combustion zone. The effects of
the smoke produced by a fire depend on the amount of
smoke produced and on the properties of the smoke. The
following section presents experimental results on smoke
emission for a variety of materials. The smoke
emission, together with the flow pattern, determines the
smoke concentration as smoke moves throughout a
building. The most basic physical property of smoke is
the size distribution of its particles. Results on size
distribution for various types of smoke and techniques
used for measuring particle size are presented in the
section "Size Distribution." The section "Smoke
Properties" focuses on those properties of greatest
concern to the fire protection community: light
extinction coefficient of smoke, visibility through
smoke, and detectability of smoke. These properties are
primarily determinded by the smoke concentration and the
particle size distribution. References for other smoke
aerosol properties, such as diffusion coefficient and
sedimentaion velocity, are also provided.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899