title: Ignition of expandable polystyrene foam by a hot particle: an experimental and numerical study.
abstract: Many serious fires have occurred in recent years due to the ignition of external building insulation materials by hot metallic particles. This work studied the ignition of expandable polystyrene foam by hot metallic particles experimentally and numerically. In each experiment, a spherical steel particle was heated to a high temperature (within 1173-1373K) and then dropped to the surface of an expandable polystyrene foam block. The particles used in experiments ranged from 3mm to 7 mm in radius. The observed results for ignition were categorized into two types: "flaming ignition" and "no ignition", and the flaming ignition limit was determined by statistical analysis. According to the experimental observations, a numerical model was proposed, taking into account the reactant consumption and volatiles convection of expandable polystyrene decomposition in air. Three regimes, no ignition, unstable ignition and stable ignition, were identified, and two critical particle temperatures for separating the three regimes were determined. Comparison with the experimental data shows that the model can predict the range of critical ignition temperatures reasonably well.
authors.affiliation: State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui 230026, PR China.
authors.forename: Supan
authors.initials: S
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui 230026, PR China. Electronic address: hxchen@ustc.edu.cn.
authors.forename: Haixiang
authors.initials: H
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui 230026, PR China. Electronic address: liunai@ustc.edu.cn.
authors.forename: Naian
authors.initials: N
authors.lastname: Liu
mesh_terms: D003252:Construction Materials; D005390:Fires; D006358:Hot Temperature; D008962:Models, Theoretical; D011137:Polystyrenes / Q000737:chemistry*
chemical_list: D011137:Polystyrenes
keywords: Building insulation materials; Expandable polystyrene foam; Hot particle; Ignition