THE EFFECT OF DIFFUSION ON THE AUTOIGNITION OF COMBUSTIBLE FLUIDS IN INSULATION MATERIALS

The autoignition of flammable fluids in lagging materials is a major p roblem faced by the process industry. It is important to ascertain whe ther such a system is safe or if it will undergo ignition for a partic ular set of conditions. In this paper, a three-component model of this system is considered which includes exothermic oxidation and endother mic evaporation processes. By assuming a slow rate of consumption of f uel and oxygen, the behaviour of the full system can be approximated a nd the safe and dangerous regions of parameter space can be identified . The effect of changes in parameters such as the size and the endothe rmicity are discussed in detail.