Titre :

Effects of flame retardants on extinction limits, spread rate, and smoke release in opposed-flow flame spread over thin cylindrical polyethylene samples in microgravity

Auteur(s) :

Li, Y. [Auteur]
Guibaud, A. [Auteur]
University College of London [London] [UCL]
Citerne, J.-M. [Auteur]
Consalvi, J.-L. [Auteur]
Institut universitaire des systèmes thermiques industriels [IUSTI]
Coimbra, A. [Auteur]
Institut universitaire des systèmes thermiques industriels [IUSTI]
Sarazin, Johan [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Bourbigot, Serge [Auteur]
174496|||Unité Matériaux et Transformations - UMR 8207 [UMET]
56663|||Institut Universitaire de France [IUF]
Torero, J.L. [Auteur]
University College of London [London] [UCL]
Legros, G. [Auteur]

Titre de la revue :

Proceedings of the Combustion Institute

Nom court de la revue :

Proceedings of the Combustion Institute

Numéro :

39

Pagination :

3919-3928

Éditeur :

Elsevier BV

Date de publication :

2023

ISSN :

1540-7489

Discipline(s) HAL :

Chimie/Matériaux
Chimie/Polymères

Résumé en anglais : [en]

Though flame retardants are considered for use in spacecraft, their performances in microgravity are still poorly understood. To assess their effects on flame extinction, opposed flame spread rate, and smoke emission in ...
Lire la suite >Though flame retardants are considered for use in spacecraft, their performances in microgravity are still poorly understood. To assess their effects on flame extinction, opposed flame spread rate, and smoke emission in the absence of buoyant flows, thin cylindrical samples of Low Density Polyethylene (LDPE) loaded with intumescent flame retardants are ignited in parabolic flights. Two types of flame retardants characterized by different mechanisms of intumescence are considered, namely Expandable Graphite, (EG), and Ammonium polyphosphate / Pentaerythritol, (AP), for which thermal stress and chemical recombination drive physical expansion, respectively. Observations are then reported and contrasted with results obtained at normal gravity for different flame retardant loads, under varying oxygen content at given ambient pressure and flow velocity. Focusing on the flame leading edge, results related to flame spread and flame extinction are analyzed first. At normal gravity, increasing the flame retardant load improves fire safety through an increase in the flame extinction limit on the one hand, and a reduction in the average flame spread rate for all oxygen contents studied on the other hand. In contrast, results in microgravity show no modification in the extinction limit over the range of flame retardant loads studied, and the benefits in average flame spread rate reduction are less pronounced. Investigating then radiative quenching at the flame trailing edge, smoke emission is never evidenced at normal gravity. However, in microgravity, the addition of flame retardants increases the range of conditions leading to smoke emission, which is detrimental to fire safety. These observations are valid for both flame retardants, yet more pronounced for EG-loaded samples than AP-loaded samples. These ambivalent effects on fire safety of AP , EG addition in microgravity, which are not evidenced at normal gravity, call for a cautious integration of flame retardants in the scope of space exploration.Lire moins >

Langue :

Anglais

Comité de lecture :

Oui

Audience :

Internationale

Vulgarisation :

Non

Établissement(s) :

Université de Lille
CNRS
INRAE
ENSCL

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Équipe(s) de recherche :

Ingénierie des Systèmes Polymères

Date de dépôt :

2023-12-12T12:39:40Z
2023-12-15T10:13:28Z