Upward Flame Spread And Critical Conditions For Pe/pvc Cables In A Tray Configuration

We demonstrate how flame spread and fire growth can be predicted in a systematic way using a fire spread and growth (FSG) model developed at FMRC and small scale flammability measurements for PE/PVC cables in trays; this material pyrolyses in a more complicated way than a non-charring (e.g., PMMA) or a simple chamng material (e.g., particle board). Similar methodology has been applied and validated for PMMA and various types of particle board. For PE/PVC cable trays, this procedure consists of the following parts: a) standard small scale flammability measurements (i.e., time to ignition, heat of combustion, product yields) and measurements of surface temperature histories and pyrolysis rates in a nitrogen atmosphere; b) a method to deduce from these small scale measurements "equivalent" material pyrolysis properties which can be inserted in a pyrolysis model to predict pyrolysis rates in fires; and c) the FSG fire spread model which uses the properties obtained in parts (a) and (b) for predicting fire growth and critical conditions for flame spread. The present work focuses on upward f i e spread predictions and measurements for a specific 3 ft high PE/PVC cable tray.