- Author
- Lyon, R. E.
- Title
- Solid-State Thermochemistry of Flaming Combustion. Final Report.
- Coporate
- Federal Aviation Administration, Atlantic City International Airport, NJ
- Report
- DOT/FAA/AR-99/56; Final Report, June 1999, 59 p.
- Distribution
- AVAILABLE FROM National Technical Information Service (NTIS), Technology Administration, U.S. Department of Commerce, Springfield, VA 22161. Telephone: 1-800-553-6847 or 703-605-6000; Fax: 703-605-6900. Website: http://www.ntis.gov
- Book or Conf
- Fire Retardancy of Polymeric Materials. Chapter 11, Marcel Dekker, Inc., New York, NY, Grand, A. F.; Wilkie, C. A., Editors, 391-447 p., ['2000', '1999']
- Keywords
- flaming combustion | thermochemistry | combustion | flammability | thermal degradation | char | kinetics | fire behavior | combustible solids | coupling | pyrolysis
- Abstract
- A self-consistent materials chemistry of flaming combustion is derived from solid-state kinetics and thermodynamics using a realistic physical model of polymer burning. The rates of solid-state (pyrolysis) and gas phase (combustion) reactions are assumed to be rapid in comparison to the rate of heat transfer at the burning surface. Coupling of thermal diffusion and chemical kinetics occurs in the surface pyrolysis zone where the rate of temperature rise for steady burning becomes the characteristic heating rate for thermal decomposition. Detailed thermal degradation chemistry is foregone in favor of a transient mass balance on the polymer, fuel gases, and solid char in the anaerobic pyrolysis zone. Closed-form, time-independent solutions for the scalar mass loss rate and char yield are obtained from the degradation kinetics which, in combination with the solid-state thermal transport and thermodynamic properties calculated from the polymer chemical structure, provide the scaling relationship between material properties and steady-burning rate. The critical condition for a nonzero burning rate in the absence of an external heat flux (flammability) can then be expressed in terms of material properties. Thermochemical predictions of ignitability and flaming heat release rate for a variety of charring and noncharring polymers are in general agreement with experimental data using the present approach.