Experimental Research on the Spatial Distribution of Toxic Gases in the Transport of Fire Smoke

Abstract

Current assessment models and experimental tests on gas toxicities in a fire hazard are mainly based on the hypothesis that uniform smoke and gas layers exist in the compartment. This study, through experiments conducted in a reduced-scale compartment—corridor model, examines the assumption and explores the characteristics of spatial distribution of toxic gases in smoke transport from a fire hazard. The results suggest that the toxic gases in the upper layer in the corridor are characterized by uniform expansion, while those in the lower layer are not. It has also been found that evolutions of the gases in different layers are not synchronous, while they are identical at the same height where the densities are close. Further analyses indicate that the formation of CO from the deoxidization of O2, CO 2, and the unburned hydrocarbon in the smoke movement delays the time of the maximum concentration.