FireDOC Search

Author
Rzeznik, M. J.
Title
Atmospheric Dispersion of Smoke Plumes Produced From Large Tire Fires.
Coporate
Worcester Polytechnic Inst., MA
Report
Thesis, August 1993, 175 p.
Keywords
fire plumes | dispersions | computer models | toxic products | combustion products | fire data | safe separation distance | air pollution | wind velocity | temperature gradients | rainfall
Identifiers
scrap tire fires; fire dynamics principals; plume theory; atmospheric effects; surface roughness; washout by rainfall; plume rise formulation; atmospheric dispersion formulation; parameter sensitivity
Abstract
The objective of this thesis has been to create a computer model which estimates safe separation distances downwind of plumes containing toxic combustion products generated by large exterior fires. Fire dynamics principals, plume theory, atmospheric dispersion theory, and available fire data are the basis for the model and computer code. This model is designed specifically to address the problem of scrap tire fires and concerns regarding the extent of the danger zone downwind. Atmospheric effects, such as atmospheric temperature gradient, wind velocity, surface roughness, and washout by rainfall are taken into account. Particle deposition and fallout due to gravitational settling and agglomeration are also considered. In addition to the dispersion algorithm, a simple method to model flame spread over the tire pile is included. Observed results from a large scale tire fire were compared to model calculations. Measured particulate dispersion dosages resulting from the Everett, Washington fire in 1984 were used, however, much of the source term information was estimated because reports from responding fire department and environmental officials did not include details needed for input to the model. Resulting dosages of five chemicals measured at the Everett, Washington site are similar (50% average deviation) to levels calculated using the model.