Characterization of highly under‐ventilated fires using the cone calorimeter

Abstract

Summary The cone calorimeter, originally designed with an ‘open configuration‘, may be used in combination with a closed‐combustion chamber in order to test specimens in oxygen‐depleted atmospheres (air vitiation effect) or in fuel‐rich combustion (ventilation effect). However, highly under‐ventilated conditions are not achievable, as a consequence of an overconsumption of oxygen due to the incomplete confinement of the flame and imperfections in the air tightness of the combustion volume. In this work, these issues were solved by lowering the combustion zone, in order to fit a 600 mm chimney on the top of the controlled‐atmosphere chamber, and further improving the sealing of the whole setup. n‐Heptane was used as a reference fuel, and its combustion properties were determined in under‐ventilated conditions. The yields of main combustion species correlated well with the global equivalence ratio, for values of Φ up to three. The use of a Fourier‐transform infrared spectrometer allowed further refinement of the total unburned‐fraction composition. The relative concentration of species like methane, ethylene, or acetylene was shown to be relatively constant over the range of under‐ventilated conditions. Copyright © 2015 John Wiley & Sons, Ltd.

Enhanced flame retardancy of polyethylene/magnesium hydroxide with polycarbosilane

“…Cone calorimeter test is considered as one of the best way in assessing combustion behaviors of materials 39 . More information can be collected 40 , among which heat release rate (HRR) and total heat release (THR) are of great importance 41 . When the global content of flame retardant is 50 wt.…”

Reaction to fire of polymethylmethacrylate and polyvinylchloride under reduced oxygen concentrations in a controlled-atmospherecone calorimeter

“…For confined under-ventilated flaming fires, the [CO]/[CO 2 ] ratio is comprised between 0.2 and 0.4. 37 In addition, the ventilation conditions and fire stages are commonly characterized by the global equivalence ratio 11,38 defined as the mass ratio of the actual fuel/ air ratio to the stoichiometric fuel/air ratio for complete combustion. If the amount of air equals the fuel-air requirement, then the conditions are stoichiometric, and the equivalence ratio equals 1.…”

“…Different designs of controlled-atmosphere cone calorimeter (CACC) have been set up in laboratories [3][4][5][6][7][8][9][10][11][12][13][14][15] to study the flammability parameters of various polymers, for example, polymethylmethacrylate (PMMA), polyethylene (PE), polypropylene (PP), or polystyrene (PS), as well as the smoke produced by under-ventilated and vitiated fires. The tests in CACC imply that phenomena can be controlled by both ventilation and vitiation of the gas supply.…”

Burning material behaviour in hypoxic environments: An experimental study examining a representative storage arrangement of acrylonitrile butadiene styrene, polyethylene bubble wrap, and cardboard layers as a composite system

“…This is important to note as ORSs also create hypoxic conditions through vitiation and key differences in material behavior have been observed between vitiated and under-ventilated conditions. 22 Where a standard CC is used, ISO5660-1:2019 calculations can be used to determine the HRR. The study conducted made use of the alternative methods outlined by Werrel 23 where the HRR is calculated with a time-dependent mole fraction of oxygen in incoming air, X A 0 O2 , rather than the constant value used in the typical CC method.…”