Extinguishment of Cooking Oil Fires by Water Mist Fire Suppression Systems

Abstract

/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://dx.doi.org/10.1023/B:FIRE. 0000039161.18616.86 Fire Technology, 40, 4, pp. 309-333, 2004-10-01 ABSTRACTA series of full-scale experiments were conducted in a mock-up commercial cooking area to study extinguishing mechanisms and effectiveness of water mist against cooking oil fires. The impact of water mist characteristics, such as spray angle, droplet size, flow rate, discharge pressure and type of nozzle, on the effectiveness of water mist against cooking oil fires was investigated. A series of oil splash experiments were also conducted to determine if the oil was splashed by water mist. In addition, the change in oil composition during heating and fire suppression was determined using Fourier Transform Infrared (FTIR) technique.The study showed that cooking oil fires were very difficult to extinguish, because they burned at high temperature and re-ignited easily due to changes in oil composition during heating and fire suppression. The water mist systems developed in the present work effectively extinguished cooking oil fires and prevented them from re-ignition. The spray angle, discharge pressure, and water flow rate were important factors to determine the effectiveness of water mist in extinguishing cooking oil fires.

Concept Design and Testing of Multi-Nozzle Water Mist Fire Suppression System

“…Although there were some temperature increase during the initial period of mist introduction, however in general the fires can be extinguish in a relatively short period of time. In addition, according to the literature the spray characteristics of individual nozzle, as well as multi nozzle arrangements, which are represented by spray coverage area, fluxs of water mist, and spray momentum are also important factors for extinguishing cooking oil fires [1][2][3][4]10]. Water mist coverage must be large enough to cover the entire oil surface and extinguish the whole flames over the oil surface at once, otherwise the flames will not be extinguished.…”

“…Nearly all accidental fire in hotels, restaurants, and fast food outlets start in kitchens, and the majority of these involve cooking oil [1]. Usually the average burning rates of cooking oils are higher than those of other hydrocarbon oils, and cooking oil fires (K class fire) are more difficult to extinguish than other liquid fires [2,3].…”

“…The use of fine water sprays as alternative method for fire control has been widely recognized [1][2][3][5][6][7][8][9]. The smaller size water mist droplets offer larger surface area for the same amount of water, allowing faster evaporation of the droplets, and more effective heat extraction from a fire.…”

“…Recently some experiments of extinguishing class K fires with water mist are carried out [1,[6][7][8]. It is necessary to thoroughly investigate the interaction of water mist with class K fires, and disclose the related principles so as to provide scientific guidance for the use of water mist in kitchens.…”

Application Of Water Mist To Extinguish Large Oil Pool Fires For Industrial Oil Cooker Protection

“…Water mist that consists of small water droplets (D v99 < 1000 µm) has been used to successfully extinguish various types of fires [3][4][5] as well as cooking oil fires in a commercial deep fat fryer without causing significant fire flare-up and re-ignition [6]. However, no research on usage of fine water mist against large cooking oil fires associated with the industrial oil cookers has been reported.…”