- Author
- Morehart, J. H. | Zukoski, E. E. | Kubota, T.
- Title
- Species Produced in Fires Burning in Two-Layered and Homogeneous Vitiated Environments.
- Coporate
- California Institute of Technology, Pasadena
- Sponsor
- National Institute of Standards and Technology, Gaithersburg, MD
- Report
- NIST GCR 90-585, December 1990, 274 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
- Contract
- NIST-GRANT-60NANB900958
- Keywords
- air | combustion products | diffusion flames | fire plumes | vitiation
- Abstract
- The chemical species produced in a buoyant, turbulent diffusion flame exposed initially to a supply of fresh air and extending into a reduced-oxygen environment containing products of combustion are investigated. The stably stratified, vitiated region is formed by placing a hood above a burner so that it accumulates the gases of the fire plume, while the direct injection of air into the upper portion of the hood allows conditions to be studied where the stoichiometry of the collected gases is different than that of the plume flow crossing the interface betwen these two regions. Measurements of the composition show that the species produced in the flame depend primarily on the stoichiometry of the gases in the vitiated region, but are independent of the fuel-air ratio of the mass transported across the interface by the plume. Experiments were conducted with natural gas, ethylene, and propylene fuels. For natural gas fires, a weak dependence of species concentrations on the temperature of the product gas layer was observed over the range 500 to 900K.