Modeling multi-stage decomposition of cotton fabrics considering char oxidation in the presence of oxygen

摘要

A theoretical model, describing thermal degradation behavior of cotton fabrics that exposed to a constant radiant heat flux, is proposed in the paper. The model describes thermal and oxidative degradation of cotton fabric under the oxygen-containing atmosphere and considers pseudo-bi-component separate-stage kinetic process. Both exothermic and endothermic reactions are included in the decomposition process. At present, gas phase oxidation reactions are not included. Comparison with experimental results demonstrates that the predictions of the mass loss rate and temperature profile with these cotton fabrics are in agreement with the experiment. Effects of thermal radiation and ambient oxygen concentration on decomposition have also been investigated. The gas phase temperature is also predicted by the present numerical model. Results from numerical model will help contribute to a better understanding of the ignition mechanism of flame-resistant cotton fabrics used for fire safety garments.