- Author
-
Atreya, A.
|
Abu-Zaid, M.
- Title
- Effect of Environmental Variables on Piloted Ignition.
- Coporate
- Michigan State Univ., East Lansing
Mutah Univ., Jordan
- Sponsor
- National Institute of Standards and Technology, Gaithersburg, MD
- Contract
- NIST-GRANT-60NANB500578
- Book or Conf
- International Association for Fire Safety Science. Fire Safety Science. Proceedings. 3rd International Symposium. July 8-12, 1991,
Elsevier Applied Science, New York,
Edinburgh, Scotland,
Cox, G.; Langford, B., Editors,
177-186 p.,
1991
- Keywords
-
fire research
|
fire safety
|
fire science
|
pilot ignition
|
environmental effects
|
wood
|
surface temperature
|
equations
|
heat flux
|
mass flux
|
thermal properties
|
weight loss rate
|
oxygen concentration
|
weight loss
- Identifiers
- thermal model; piloted ignition
- Abstract
- In this paper the effect of environmental variables on piloted ignition of wood is investigated both experimentally and theoretically. The environmental variables considered are the moisture content of the solid, wind speed and its oxygen concentration and external radiation. Simultaneous measurements of weight loss rate, ignition time, sample surface temperature, oxygen depletion and production of CO2, CO, total hydrocarbons, and water vapor were made. As expected, the presence of moisture delays the decomposition process and dilutes the decomposition products. The surface temperature and the evolved mass flux at ignition increased with increase in moisture content, decrease in oxygen concentration and increase in air velocity. All the ignition data are correlated according to an equation derived for surface temperature with convective and radiative heat losses. This equation reveals how the moisture content, air velocity, oxygen concentration and external radiation affect the ignition delay time. It also enables the determination of the critical incident heat flux below which piloted ignition does not occur.