Fire Safety Science Digital Archive

A convenient and basic measurement on smoke produced by a given material is the specific extinction area. It is, in theory, the more appropriate quantity by which to attempt correlation between small and large-scale data. In fact, it is now well established that the smoke yield and the soot particle size are increased as the fire size increases. In general, procedures on how to integrate such complex phenomenon, as particle surface grow process as well as coagulation and coalescence, into correlation, have not yet been proven. Despite this difficulty, the present authors began a basic small-scale study on extinction properties of mixtures of smokes, using the concept of specific extinction area. A theoretical relationship between the specific extinction areas of the different fuels involved (burning side by side or one in the flame of another) has been established. Dynamic measurements with a flow-through system have been made. Comparison with the theoretical development shows a satisfying agreement.