Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Gas species and thermal measurements preceding backdraft events in a 2/5th scale compartment

Published

Author(s)

Ryan Falkenstein-Smith, Thomas Cleary

Abstract

This report documents real-time and time-averaged temperature, global and local equivalence ratios, and oxygen, carbon dioxide, and carbon monoxide concentration measurements made at various positions in an isolated 2/5th scale compartment prior to a backdraft event. The compartment was subjected to methane, propane, and propylene fires of different sizes and fuel flow times. Backdrafts were observed to vary depending on the fuel source. Gas mixture composition measurements obtained before an anticipated backdraft were obtained through various gas analysis techniques, including an enhanced phi meter, a gas analyzer equipped with one paramagnetic and two non-dispersive infrared sensors, and a Gas Chromatograph/Mass Spectrometer System. Measurements and the influence of transient compartment conditions, including opening configuration, spark igniter location, fire size, and fuel flow time, are discussed in detail. The likelihood of backdraft under these compartment configurations is typically improved with a higher spark igniter location and fire size, smaller compartment opening, and shorter fuel flow time.
Citation
Technical Note (NIST TN) - 2185
Report Number
2185

Keywords

Backdraft, Gas Species Concentrations, Global Equivalence Ratio, Local Equivalence Ratio, Reduced-Scale Enclosure, Real-time Measurements, Time-averaged Measurements.

Citation

Falkenstein-Smith, R. and Cleary, T. (2001), Gas species and thermal measurements preceding backdraft events in a 2/5th scale compartment, Technical Note (NIST TN), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NIST.TN.2185, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=933563 (Accessed April 25, 2024)
Created January 1, 2001, Updated November 29, 2022