Fire Safety Science Digital Archive

A set of small-scale experiments was carried out to study the effect of a water spray on the re-ignition characteristics of solid fuels. The influence of other key parameters, such as the incident heat flux and pre-burn, was also investigated. The experiments were conducted on specimens of wood and PMMA using a cone calorimeter. A water spray was produced by a small commercial nozzle. As expected, the effect of water on the re-ignition time was found to be significant. It was also found that the re-ignition characteristics of charring materials, such as wood, are quite different from non-charring materials (e.g. PMMA) mainly due to the structural differences. Based on the experimental observations a set of empirical correlations was obtained for both wood and PMMA samples. Predictions of the re-ignition time made by these correlations agree well with the measurements. Simulations of the re-ignition times were also performed using a detailed mathematical model. Comparisons with the experimental data are provided.