evaluation of surfactant enhanced water mist performance

Evaluation of Surfactant Enhanced WaterMist Performance

Georges LeFort, Ecole Nationale Superieure de Mecanique et d’ Aerotechnique(ENSMA), Futuroscope Chasseneuil Cedex 86960, France

Andre W. Marshall*, Department of Fire Protection Engineering, University ofMaryland, 0151 Glenn L. Martin Hall, College Park, MD 20742, USA

Martial Pabon, DuPont Chemical Solutions Enterprise, Chantereine, Mantes laJolie, France

Received: 22 March 2006/Accepted: 17 September 2008

Abstract. Water-mist technology provides efficient fire suppression for compart-ments while minimizing water usage. Even with the many advantages of water mist

systems, there is still room for improvement. Water mist systems have demonstratedeffectiveness at suppressing flammable liquids (Class B) fires in compartments. How-ever, an especially challenging fire suppression scenario for water mist systems is thesmall Class B fire. This scenario is often realized after a large fire has been reduced in

size or ‘controlled’ by water mist. The small fire scenario is challenging because asmall fire may not be able to generate enough vaporized water to displace sufficientoxygen for complete extinction. It should also be noted that even if the Class B fire is

extinguished with a water mist system, re-ignition from the hot surrounding surfacesmay occur at any time. In the present work, an additive is introduced into the watersupply and its effect on the water mist suppression performance is studied. This Fora-

facTM additive is a specific formulation, which includes fluorinated surfactants forcreating a robust fire suppression foam. The enhanced suppressant exiting the mistnozzle is dispersed in the form of small droplets (not as a continuous foam) similarto a pure water mist spray. However, these droplets create a foam blanket on the

surface of the fire, which acts to isolate the fuel from the air. With this formulation,the efficiency of the water mist system is improved even on small fires and mostimportantly the re-ignition of class B fires is prevented.

Keywords: surfactant, water mist, suppression, class B fires

1. Introduction

The potential benefits of surfactant enhanced water mist are evaluated in thisstudy. The focus application for surfactant enhanced water mist is the protectionof machinery spaces. Water mists are often used to suppress fires in confinedspaces as an alternative to gaseous agents. Foams are commonly used to extin-guish Class B liquid fires such as those created by leaks or spills. The mist foam

* Correspondence should be addressed to: Andre W. Marshall, E-mail: [email protected]

Fire Technology, 45, 341–354, 2009

� 2008 Springer Science+Business Media, LLC. Manufactured in The United States

DOI: 10.1007/s10694-008-0068-212

combination is a logical choice for machinery spaces because these spaces areoften confined and full of flammable liquids.

1.1. Water Mists

Water mists have been studied for at least 50 years [1]. During the past decadeenvironmental, economical issues, and technological breakthroughs have broughtthis technology to the forefront. Water mists are defined by NFPA 750 as a waterspray for which the DV99 (99% volume diameter) as measured at the coarsest partof the spray in a plane 1 m from the nozzle, at its minimum operating designpressure, is less than 1000 lm [2]. A variety of water mist technologies are avail-able for creating these small drops [3]. In this study, an intermediate pressure(12.1–34.5 bar) water mist nozzle is used.

The small drops in a water mist create a large surface area (for a given volumeof water) to enhance vaporization. The vaporization of the mist provides bothoxygen displacement and cooling. These effective suppression mechanisms allowwater mists to use less than one tenth of the water necessary for standard sprin-klers, providing a distinct advantage over sprinklers in terms of water supply. Thedecreased water delivery requirements also reduce the potential for water damageto sensitive equipment. One of the most attractive advantages of water mist is thatit does not splatter liquid fuel like conventional sprinklers during suppression ofClass B fires. The efficacy of water mist fire suppression has been demonstrated innumerous studies and in a wide range of applications including Class B pool fires,spray fires, fires in aircraft cabins, shipboard machinery, engine room spaces, ship-board accommodation spaces and electronics applications [4]. For machineryspaces on ships and turbine enclosures, water mists are helpful to extinguish firesand moreover to cool hot surfaces to prevent possible reignition.

1.2. Foams

Foams are made of foam concentrate, water, and air (typically >80%) [5]. Sur-factants are the principle components of the foam concentrate. A variety of sur-factants are used in the foam concentrate to not only facilitate the formation offoam, but also to enhance its spreading characteristics. Surfactants are long mole-cules consisting of a hydrophilic head and a hydrophobic tail. These surfactantsare suspended in liquid solutions at low concentrations. At a free surface, the sur-factants adopt a preferred orientation where the hydrophobic head is attractedtoward the water and the hydrophobic tail is repelled away from the water towardthe gas. This behavior is illustrated in Figure 1. The polar separation forces cre-ated by the surfactant at the liquid–gas interface facilitates organization of thetwo fluids into foam.

Typically, foam is formed by entraining gas into liquid. This can be accom-plished through direct injection or agitation. The forces created by the surfactantsnear liquid–gas interfaces in this mixture act to trap liquid in thin layers or‘lamella’ between volumes of gas producing foam [6]. The surfactants also reducethe surface tension of the liquid. In fire suppression applications, this effect isexploited to help spread a protective film of water and foam over liquid fuel sur-

342 Fire Technology 2009

faces as shown in Figure 2. Surfactants can be fluorinated or hydrocarbon based,but fluorinated surfactants have a lower surface tension and associated exceptionalfilming characteristics. Hydrocarbon surfactants, however, have superior foamingcharacteristics. Fluorinated and hydrocarbon surfactants are typically used toge-ther in fire suppression applications to take advantage of their respective perfor-mance benefits.

Fire fighting foams are commonly used for extinguishing spill fires involvingflammable liquids such as polar solvents (i.e. methanol) and non-polar solvents

Figure 1. Surfactant molecules stabilizing a thin liquid film in foam[6].

Fuel

Foam Spread

Film

Figure 2. Aqueous film forming foam (AFFF) spreading over fuelsurface.

Evaluation of Surfactant Enhanced Water Mist Performance 343

(i.e. heptane). To extinguish liquid fires, foam must be quickly spread at thesurface of the fuel to prevent fuel gasification and reduce heat loading to the fuelsurface [5]. Foams are also used to maintain a protective barrier at the fuelsurface in order to prevent these substances from igniting or reigniting. The protec-tive barrier formed by the foam is only temporary. Over time, the high radiantflux from the fire or surrounding hot surfaces acts to destroy the protective barrierestablished by the foam [7].

1.3. Surfactant Enhanced Water Mist

Addition of surfactants into the water mist supply has the potential of providingthe cooling and oxygen displacement benefits of water mist combined with thefuel isolation advantages of foam. The author is only aware of one other study,which has tested the effect of surfactant additives on the suppression performanceof water mists [8]. In this study, Kim et al. performed suppression experimentsusing swirl-type nozzles and standard pendant sprinklers with both standardfoaming additives and aqueous film forming foam (AFFF) additives. These sup-pression tests were conducted in a variety of nozzle orientations on Class B andwood crib fires in a well-ventilated enclosure. The characteristic drop sizes in thewater sprays were measured in this investigation for both nozzle types; however,no measurements were reported for the sprays with additives. The suppressiontests revealed that the sprinkler had little effect on the Class B fires. In contrast,the pure water mist was able to control, but not extinguish the Class B fires.When surfactants were added, the Class B fires were easily extinguished. However,Kim noted that much higher concentrations of AFFF additives (1–3%) wererequired to achieve suppression performance similar to standard foaming agentsused at a much lower concentration (0.3%). A thin foam layer was reported togrow on the surface of the liquid fuel fires for all of the tests with additives. Kim’sstudy focused primarily on evaluating suppression performance. The burnbackcharacteristics of the post-extinction foam layer were not considered.

In order to realize the benefits of surfactant enhanced water mist, the mist mustbehave like a vaporizing spray after leaving the injector and behave like a spread-ing foam upon arrival at the fuel surface. In the current investigation, the behav-ior of the surfactant enhanced water mist is evaluated with respect to thesefeatures from the injector exit to the fuel surface. Ultimately, this behavior willgovern the extinction and reignition delay (burnback) performance. The specificobjectives of this investigation are to characterize the surfactant effects on sprayproperties, extinction times, and burnback times in Class B fires. These objectivesare achieved through spray experiments, fire suppression experiments, and re-igni-tion delay (burnback) experiments.

1.4. Surfactants and the Environment

A proprietary surfactant (Forafac WMTM) was used in this study. ForafacWMTM is a recipe containing various chemicals including a partially fluorinatedsurfactant. In 2002 the primary manufacturer of fluorinated surfactants for firefighting foams stopped their manufacturing activity largely because of a potential


persistent bioaccumlative and toxic (PBT) chemical issue. This supplier was usingthe electrochemical fluorination (ECF) process to manufacture their fluorosurfac-tants for fighting foams. This ECF process made PFOS-derived products and theresulting fire fighting foams contained various residual levels of PFOS (Perfluoro-octane sulfonate). An Organization for Economic Co-operation and Development(OECD) hazard assessment has been performed on the basis of information thatwas available in 2002. This assessment concluded that perfluorooctane sulfonatesare persistent, bioaccumulative and toxic to mammalian species and therefore mayindicate cause for concern.1 The fluorinated surfactant present in Forafac WMTM

is manufactured by DuPont using the telomerization process. The process usedto make the fluorinated surfactant present in Forafac WMTM does not use orcontain PFOS either as active ingredient, as a byproduct, or as a degradationproduct.

Furthermore, the surfactant Forafac WMTM has been designed to provide opti-mal fire suppression performance while using a minimum amount of additive inwater. Knowing that the best results in terms of fire suppression are obtained onClass B fires, the use of Forafac WMTM is recommended on this specific type of fire.It should also be noted that water mist systems are installed in closed rooms. Hence,after a fire event, aqueous effluents and wastes can be recovered and treated asappropriate [5]. A recent toxicological study [9] demonstrated that Forafac WMTM

is considered to have very low toxicity by inhalation. In fact, at design concentra-tion, it is not classifiable as a dangerous substance (LC50 > 5 mg/l) according tothe Official Journal of the European Communities EEC Directive 93/21.

2. Approach

Spray characteristics, suppression performance, and burnback performance wereevaluated at various concentrations of Forafac WMTM. The surfactant was thor-oughly mixed with water in the water supply reservoir prior to testing. Spraycharacterization and suppression experiments were also conducted using purewater to establish a performance baseline. The spray characterization was con-ducted using a spray chamber facility. High speed photography was used toevaluate changes in the atomization process resulting from surfactant addition.Drop sizes were also measured with a Malvern particle size analyzer to deter-mine the impact of surfactant addition on the drop size distribution of thespray. The suppression and burnback experiments were conducted in a burnroom using a test configuration relevant to machinery spaces where Class B firesare a hazard. The type of fuel, fire size, and nozzle type were selected to reflectmajor fire fighting foam and water mist standards and typical fire scenarios formachinery spaces.

1European parliament legislative resolution on the proposal for a directive of the European Parliamentand of the council relating to restrictions on the marketing and use of perflurooctane sulfonates(amendment of council directive 76/769/EEC).


2.1. Spray Characterization

Spray characteristics of a Tyco-Grinnell intermediate pressure AquaMist AM4nozzle are evaluated in this investigation. The AM4 nozzle is illustrated inFigure 3. The spray behavior is described through photographs taken near theinjector and drop size measurements performed in a plane well below the injector.Short time exposure photographs were taken with a Canon D30 digital SLR cam-era and a 550EX flash. The flash setting was fixed at its minimum setting of about1/6400 s. Even with this short exposure time, clear images of the spray could onlybe obtained at operating pressures below 1.72 bar which is much lower than therecommended operating pressure range. A Malvern Spraytec particle size analyzerwas used to measure the drop sizes at 0.5 m below the injector. Drop sizes weremeasured at five radial locations extending from the centerline to 0.6 m. Anexposed probe volume of approximately 12.3 cm3 was used for these measure-ments. An average planar drop size distribution is calculated from this profile.The average is weighted based on the drop concentration and flux area assumingaxisymmetric flow.

2.2. Suppression Experiments

The experiments were designed to produce understandable and easy to compareresults for evaluation of combined water mist and foam performance under realis-tic conditions. Many fire tests for water mist have already been conducted [10–13].In this study, an available small-scale burn room was used having a total volumeof 9.1 m3 having two opposing vents of 1.6 and 0.093 m2 and one overhead vent of0.067 m2. An illustration of the suppression experiment configuration is providedin Figure 4. A typical intermediate pressure water mist nozzle was selected for thisinvestigation as described previously. Only one nozzle was used because of thesmall burn room volume. A fire size of 210 kW was selected to adequately chal-lenge the nozzle. The fire size is based on quasi-steady measurements during freeburn experiments. This fire was created with a 0.53 m diameter pan of heptane.The centerline of the pan was placed 0.56 m from the centerline of the nozzle. An

Figure 3. Medium pressure Tyco-Grinnell AquaMist AM4 nozzle usedin this study.


off-axis fire location was chosen to improve the repeatability of the extinction timemeasurements.

The primary focus of the suppression experiments was to quantify the extinc-tion time. Detailed measurements were also conducted to characterize the suppres-sion behavior. Thermocouple measurements were taken at ten equally spacedlocations above the fire at elevations ranging from 0.28 to 1.9 m above the floor.Type K, 0.010’’ wire exposed junction thermocouples were used for these measure-ments. A target was also placed 0.53 m (one pool diameter) from the centerline ofthe pool fire to evaluate heat loading to objects in the vicinity of the pool fire dur-ing suppression. The target is instrumented with a Gardon heat flux gauge andfive Type K surface thermocouples. Digital video was also acquired during thesuppression experiments for analysis of the fire size, visualization of the foam for-mation, and visualization of the flame behavior near the fuel surface.

The surfactant concentrations are expressed in terms of mass percentage ofactive ingredient. Multiple tests were conducted for each suppressant to ensurethat the data is repeatable. For each test, a free burn was conducted for 60 s toallow the pool fire to reach a quasi-steady burning rate. The nozzle was activatedat the end of the free burn period and suppressant was applied until extinction oruntil all of the fuel is consumed. The nozzle was operated at an injection pressureof 12.1 bar for all tests delivering approximately 0.73 m3 h-1 of water. Withoutthe fire, the application rate to the pan was measured to be 3.0 kg min-1 m-2.This experimental approach provides extinction times as well as detailed suppres-sion data to facilitate analysis and comparison of this extinction time performancefor each of the suppressants.

2.3. Burnback Experiments

After extinction, the nozzle was allowed to operate for an additional 60 s to com-pletely coat the fuel surface with suppressant. After the nozzle was shut-off, a

Figure 4. Burn room configuration for suppression and burnbackexperiments, V = 9.1 m3.


small pan (0.15 m diameter) filled with heptane fuel was placed in the center ofthe large pool. This small pan was ignited exactly 180 s after completion of thecoating period. The time to reignite 50% of the large pool was determined. Thisburnback time is defined as the reignition time. Digital video of the foam degra-dation and reignition was also recorded and evaluated during these experiments.

3. Results

3.1. Spray Characterization

Atomization behavior is compared using pure water and a surfactant–water mix-ture with the AM4 intermediate pressure nozzle. Figure 5 shows the short expo-sure time photographs of the atomization process. The general atomizationmechanisms are clearly observed for both pure water and the 0.05% ForafacWMTM mixture. The jet is first deflected to form a sheet. Aerodynamic wavesgrow on the sheet and break into ligaments. These ligaments ultimately break toform drops. The Forafac WMTM image shows numerous discrete drops beingformed near the injector just as in the pure water case. It can be concluded thatthe spray is dispersed in the form of discrete drops even when surfactant is addedto the water. However, the Forafac WMTM image shows a more opaque spraywith larger fragments being created near the frame arms. This may indicate thatsome foam is generated at the injector and that the drop size is altered by theaddition of surfactant.

Drop size measurements taken 0.5 m below the nozzle reveal that the drop sizesincreases with the addition of surfactant. The measured drop size distributions for

Figure 5. a Atomization of pure H2O. b Atomization of a surfactant–H2O mixture (0.05% ForafacTM) using a medium pressure AquaMistAM4 mist nozzle. Nozzle operated at a low pressure 25 psi to imagedetails of the initial spray.


pure water and 0.20% Forafac WMTM are provided in Figure 6. It is clear fromthe measured distributions that the drop size increases with the addition of surfac-tant. Characteristic drop sizes were calculated from these distributions and arepresented in Table 1. The Sauter Mean Diameter (SMD) is given bySMD ¼

PniD3

i =P

niD2i summed over all possible drop sizes in the measured

spray. The SMD represents a characteristic drop size having the same volume todiameter ratio as the measured spray. Alternatively, the DV50 provides a volumebased characteristic drop size: 50% of the spray volume is contained in drop sizessmaller than DV50. Both characteristic drop sizes increases by more than 40% withthe addition of 0.20% ForafacTM.

Figure 6. Measured volume distributions for pure H2O and 0.2%ForafacTM in a plane 0.5 m below the AM4 nozzle; pure H2O and0.2% FORAFAC volume distributions overlap (indicated with darkgray).

Table 1Drop Size Measurements of Pure H2O and Surfactant–H2O Mixtures. Drop Size Measurements RepresentPlanar Averages 0.5 m Below the Nozzle

Concentration of active matter Pure H2O 0.05% ForafacTM 0.2% ForafacTM

SMD (lm) 133 167 187

Dv50% (lm) 217 265 306


This drop size increase is surprising because surfactant reduces the surfacetension, which should facilitate atomization. The conventional effect of surfacetension on atomization can be understood through the Weber number,We ¼ qU2L=r, of an arbitrary volume of liquid having characteristic length Lwhere the density, q, and relative velocity, U, are best thought of as representinggas quantities. The We describes the ratio of inertial forces to surface tension for-ces. At critically high We, the inertial forces and associated shear overcome thesurface tension forces causing the liquid volume to deform and fragment. If thesurface tension is reduced, the We becomes supercritical at smaller characteristiclengths and corresponding smaller drop sizes. However, the drop size measure-ments do not support this argument.

The previous We argument does not strictly apply to surfactant enhanced flows.Although surfactants reduce surface tension, it does so slowly. The time scales forsurface tension reduction by surfactant diffusion and re-orientation on ‘fresh’ fluidsurface is on the order of seconds. However, the entire spray surface is generatedvia atomization in milliseconds. Therefore, the surfactant does not have sufficienttime to reduce the surface tension before atomization is completed. During theatomization process, the surface tension of the surfactant–water mixture is essen-tially the same as that for pure water. Recognizing the disparity in time scalesbetween surface creation and surface tension reduction explains why the drop sizeshould not decrease with surfactant addition, but does not shed light on why thedrop size increases. The increase in drop size may be explained by agglomerationor shear induced foaming as the drops travel through the air. These possibilitiescontinue to be explored, but as of yet no precise explanation has been determinedfor this phenomenon.

3.2. Suppression Experiments

The suppression experiments provide insight into the qualitative and quantitativebehavior of surfactant enhanced water mist. Figure 7 shows the transient averagesurface temperature of the target placed inside of the compartment. Differentstages in the test are clearly observed in this figure. A free burn stage is observed,followed by a cooling stage, and finally a suppression stage. It should be notedthat this suppression stage is completed by extinction in the cases with surfactant;however, the pure water is unable to extinguish the fire. Heat flux measurementsto the target also show similar trends. The suppression behavior can be seen moreclearly in the thermocouple measurements taken above the pool. It is important tonote that these thermocouple measurements should not be interpreted as gas tem-peratures. These thermocouples are cooled by impinging water drops making itdifficult to relate the measured temperature to the gas temperature. However,these measurements provide useful qualitative information related to the flameheight. Figure 8 shows the transient temperature distribution for pure water andfor 0.20% ForafacTM. It is clear that the pure water mist quickly cools the com-partment and limits the flame height; however, the flame persists at its suppressedcondition. The 0.20% ForafacTM mixture also quickly cools the compartment butcontinues to reduce the size of the flame until it is completely extinguished. The


path to extinction can also be observed in the fire suppression video images.Figure 9 shows snapshots of the fire at various times after activation of the nozzlefor the 0.20% ForafacTM case. After 20 s of application, islands of foam areclearly seen on the surface of the pool. By 60 s, these islands of foam have con-nected forming a nearly continuous layer of foam. This foam layer limits the fuelsurface available for burning and drastically reduces the fire size. The exposed fuelsurface continues to decrease until the fire is completely detached from the surface(blown out) resulting in extinction. The impact of the surfactant addition is clearlyseen in Table 2. A fire that could not be extinguished with pure water is easilyextinguished with 0.05% ForafacTM in about 214 s and about 90 s with 0.20%ForafacTM.

3.3. Burnback Experiments

After the pool fire is extinguished the nozzles remains on for 60 s. During thisperiod of time the foam completely coats the surface of the fuel. The mass fluxduring this period is approximately 3.0 kg m-2 min-1. Table 3 shows the burn-back times describing how long the pool is protected from reignition. With 0.05%ForafacTM, the pool is protected for nearly 9 min and with 0.20% Forfac the poolis protected for over 10 min. This data indicates that burnback resistance may beimproved further by increasing the surfactant concentration.

Figure 7. Average target surface temperatures illustrating path toextinction for surfactant-H2O mixtures.


Figure 8. Thermocouple measurements above the pool during apure H2O suppression experiments showing a persistent fire. b0.20% Forafac suppression experiments showing fast and completeextinction.

Figure 9. Photograph of foam spreading and flame size reductionduring 0.20% Forafac suppression experiments.


4. Conclusions

This study evaluates the potential benefits of surfactant enhanced water mistthrough characterization of spray properties, suppression behavior, and re-ignitionbehavior. High-speed photographs reveal that the behavior of the spray, thebreakup length, and even the spray pattern are not fundamentally modified withthe addition of surfactant; although drop size measurements show that the dropsize unexpected increases for surfactant–water mixtures. A possible explanation ofthe measured drop size increase could be an agglomeration or shear foaming phe-nomenon, but as of yet no precise explanation has been determined. Visualizationexperiments are currently being refined to gain insight into this surprising behavior.

Suppression mechanisms are maintained or improved when surfactant–watermixtures are used with medium pressure water mist nozzles. The cooling stageremains virtually the same as that of pure water for surfactant–water mixtures.However, the overall extinction behavior is improved with surfactant additionsince foam is formed on the fuel surface and gradually reduces the fuel surfaceexposed to oxidizer. This research clearly demonstrated that a water mist gener-ated with pure water is unable to extinguish a pool fire that is easily extinguishedwhen surfactant is added. Moreover surfactant provides a burnback or re-ignitionresistance by creating a foam layer at the fuel surface. The re-ignition is signifi-cantly delayed with surfactant whereas no protection is provided by pure water.The burnback resistance is shown to increase with increasing concentration.

Acknowledgements

This work is supported by DuPont de Nemours (France). Special appreciation isgiven to Ms. Wu Di and Messrs. Yaniv Yankovich and Andy Blum for their helpin establishing facilities and conducting the experiments used in this investigation.

Table 2Extinction Time Measurements

Concentration of active matter Pure H2O 0.05% Forafac 0.2% Forafac

Test 1 extinction time (s) NA* (460) 196 70

Test 2 extinction time (s) NA* (429) 231 110

Average extinction time (s) NA* (435) 214 90

*Extinction times in parenthesis result from depletion of fuel in the pan.

Table 3Re-Ignition (Burnback) Time Measurements

Concentration of active matter 0.05% Forafac 0.2% Forafac

Test 1 burnback time (s) 540 639

Test 2 burnback time (s) 511 647

Average burnback time (s) 526 643


References

1. Committee on Assessment of Fire Suppression Substitutes and Alternatives to Halon,

Naval Studies Board, Commission on Physical Sciences, Mathematics, and Applica-tions, National Research Council (1997) Fire suppression substitutes and alternatives tohalon for U.S. Navy applications. National Academy Press, Washington, DC

2. NFPA (1996) 750: standard on the installation of water mist fire protection systems.

National Fire Protection Association, Quincy, MA3. Grant G, Brenton J, Drysdale D (2000) Fire suppression by water sprays. Prog Energy

Combust Sci 26:79–130. doi:10.1016/S0360-1285(99)00012-X

4. Notarianni KA (1994) Water mist fire suppression systems. In: Proceedings of the tech-nical symposium on halon alternatives. Knoxville, TN

5. Pabon M, Copart JM (2002) Fluorinated surfactants: synthesis, properties, effluent

treatment. J Fluor Chem 114:149–156. doi:10.1016/S0022-1139(02)00038-66. Weaire D, Hutzler S (1999) The physics of foams. Clarendon Press, Oxford7. Boyd CF, diMarzo M (1998) The behavior of fire-protection foam exposed to radiant

heating. Int J Heat Mass Transfer 41:1719–1728. doi:10.1016/S0017-9310(97)00280-9

8. Kim AK, Dlugogorski DS DZ, Mawhinney JR (1994) The effect of foam additives onthe fire suppression efficiency of water mist. In: Proceedings of the halon options techni-cal working conference. Albuqerque, New Mexico

9. Pabon M (2005) New additive for water mist systems on class B fires: toxicologicalstudy on breathable particles. In: 6th international water mist association conference.Berlin, Germany

10. Arridson M, Hertzberg T (2003) The Vinnova water mist research project: a descriptionof the 500 m3 machinery spaces. SP Swed Natl Test Res Inst SP 19

11. Pepi JS (1995) Performance evaluation of low-pressure water mist system in a marinemachinery space with open doorway. In: Proceedings of the halon options technical

working conference. Albuqerque, New Mexico12. Ural EA, Bill RG (1995) Fire suppression performance testing of water mist systems

for combustion turbine enclosures. In: Proceedings of the halon options technical work-

ing conference. Albuqerque, New Mexico13. UL2167: water mist for nozzles for fire protection service. Underwriters Laboratories,

USA February 2004


http://dx.doi.org/10.1016/S0360-1285(99)00012-X

http://dx.doi.org/10.1016/S0022-1139(02)00038-6

http://dx.doi.org/10.1016/S0017-9310(97)00280-9

evaluation of surfactant enhanced water mist performance

Documents