Chemical Flame Suppression by Phosphorus-Containing Compounds
Abstract
Several techniques were used to aid in the assessment of PCCs as flame suppressants: GC/MS with chemical derivatization, a qualitative toxicology assessment of the byproducts, measurements of the global extinction strain rate, emission spectroscopy. We also developed two important new capabilities: (1) laser-induced fluorescence (LIF) to measure concentrations of OH (a key flame radical) as a measure of suppressant effectiveness and as a means of understanding the mechanism of flame suppression, and (2) droplet generation and feed systems to enable the future evaluation of low-vapor-pressure PCCs as liquids or aqueous solutions. Diethyl methylphosphonate and dimethyl phosphonate were tested as vapor-phase additives. Their effect on the global extinction strain rates of the methane/air flames indicated that they had flame-suppression effectivenesses very similar to those of the PCCs tested previously. The following stable byproducts were identified in a methane/air flame doped with DMMP: methyl methylphosphonate, P(=1-)(-CH3)(-OCH3)(-OH); dimethyl phosphate, P(=0)(-OCH3)2(-OH); monomethyl phosphate, P(=O)(-OCH3)(-OH)2; methylphosphonic acid, P(=O)(-CH3)(-OH)2; phosphonic acid, P(=O)(-H)(-OH)2; phosphorous acid, P(-OH)3; orthophosphoric acid, P(=O)(-OH)3, none of which is highly neurotoxic. A continuum emission and features associated with PO and PH were identified in emission spectra in DMMP-doped methane/air flames. Preliminary OH LIF and electrospray results are presented.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 29, 1999
- Accession Number
- ADA418404
Entities
People
- E. M. Fisher
- F. C. Gouldin
- J. W. Gillett
- M. A. Macdonald
- T. M. Jayaweera
Organizations
- Sibley School of Mechanical and Aerospace Engineering