Experimental and numerical investigation of the gas‐phase effectiveness of phosphorus compounds

Abstract

Summary The effectiveness of phosphorus‐containing compounds as gas‐phase combustion inhibitors varies widely with flame type. To understand this behavior, experiments are performed with dimethyl methylphosphonate (DMMP) added to the oxidizer stream of methane–air co‐flow diffusion flames (cup‐burner configuration). At low volume fraction, phosphorus (via DMMP addition) is shown to be about four times as effective as bromine (via Br2 addition) at reducing the amount of CO2 required for extinguishment; however, above about 3000 μL/L to 6000 μL/L, the marginal effectiveness of DMMP is approximately zero. In contrast, the diminished effectiveness does not occur for Br2 addition. To explore the role of condensation of active phosphorus‐containing compounds to the particles, laser‐scattering measurements are performed. Finally, to examine the behavior of the flame stabilization region (which is responsible for extinguishment), premixed burning velocity simulations with detailed kinetics are performed for DMMP addition to methane–air flames. Analyses of the numerical results are performed to understand the variation in the inhibition mechanism with temperature, agent loading, and stoichiometry, to interpret the loss of effectiveness for DMMP in the present experiments. Copyright © 2015 John Wiley & Sons, Ltd.

A comparison of the gas-phase fire retardant action of DMMP and Br2 in co-flow diffusion flame extinguishment,

“…It has been found that the effectiveness of phosphorous compounds in gaseous flames varies widely with flame type [1]. Clearly, the flame configuration has an impact on the gas-phase action of the phosphorus compounds, and work is being conducted to understand the reasons [1, 26,27].…”

Microfluidic fabrication of polysiloxane/dimethyl methylphosphonate flame‐retardant microcapsule and its application in silicone foams

“…Dimethyl methylphosphonate (DMMP) is a very effective water‐soluble liquid flame retardant. In a premixed flame, DMMP was found to be approximately 141 times (on a molar basis) as effective as CO 2 at reducing the burning velocity . There is a synergistic effect of the elements phosphorus and silicon on the flame retardance.…”

“…In a premixed flame, DMMP was found to be approximately 141 times (on a molar basis) as effective as CO 2 at reducing the burning velocity. 13,14 There is a synergistic effect of the elements phosphorus and silicon on the flame retardance. H.F. Zhong et al 15 reported that with 30-wt% phosphorus-silicon synthesized flame retardants, the limiting oxygen index (LOI) value of poly (2,2-propane-(bisphenol) carbonate)/acrylonitrile butadiene styrene (PC/ABS) was enhanced from 21.2 to 27.2 vol%, and the char yield was improved from 12% to 17%.…”

Intumescent Coatings Based on Tannins for Fire Protection

“…The substrate coated with epoxy resin was unprotected during the fire test due to the immediate degradation of the epoxy resin, which made contact between the fire and steel substrate possible, highlighted in Figure 7(a). The formulations with the tannin demonstrated an increase in residue and char formation promoted by its high aromaticity, which contributed to the charring effect and prevented the of hydrogen and hydroxyl radicals by recombination of phosphorus radicals in the gas phase 42 . XRD demonstrated the presence of iron oxides on the steel without intumescent coating, as shown in Figure 8.…”