Interaction of water mists with a diffusion flame in a confined space

This paper describes the study of the interaction of water mists with a dif fusion flame in a confined space with proper ventilation control. Water mis t was generated by a single pressure nozzle and diffusion flames were produ ced from ethanol and pine samples, respectively. The LDV/APV system was emp loyed to determine the water mist characteristics. The Cone Calorimeter was used to measure the heat release rate, oxygen and carbon monoxide concentr ations and other important parameters of the interaction under various cond itions. The test results showed that water mist suppressed the diffusion fl ame in the confined space through oxygen displacement, evaporative cooling and heat radiant attenuation, and enhanced the combustion through expansion of the mixture and chain reaction as well. Suppression played the dominati ng role when the water mists with enough volume flux were applied to the di ffusion flame in confined space. The poorer was the ventilation, the easier the suppression. The water mists had a more complex effect on the solid sa mple than the liquid, and affected the smoke release rate and movement. (C) 1999 Elsevier Science Ltd. All rights reserved.