• Journal of the Korean Society of Safety
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• v.29 no.4
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• pp.78-84
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• 2014

Viscosity agents were added to water to improve extinguishing performance of low pressure water mist suppression system on wood cribs fire, and a small scale wood cribs fire experiment was conducted to measure the extinguishing performance. CMC and agar were used for viscosity agent and as the amount of viscosity agent enlarges, it showed the increase of the viscosity of aqueous solution and the decrease of the fluidity. On wood cribs fire experiment, the extinguishing efficiency was improved with supplemental viscosity agent as it enhanced the adhesive time of aqueous solution on the wood, and therefore expanded the contact time of fire surface. The surface tension of aqueous solution was decreased with the addition of agar which to be assumed as an increase factor of extinguishing efficiency. By the extinguishing experimental result, the most effective extinguishing agent was CMC 0.6 wt.%, with the flame suppression time and the extinguishing time were reduced by 70s and 93s respectively at this concentration.

• Fire Science and Engineering
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• v.23 no.2
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• pp.78-84
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• 2009

We carried out fire extinguishing experiments with three kinds of water mist nozzle system. Fire extinguishing experiment according to installed nozzle height and fuel pan location was done. And fire extinguishing performance was compared with plain water and foam agent mixed solution. Water mist nozzle height was varied with 4m, 3.5m and 3m and position of fuel fan was varied 0.5m and 1m from the center of water mist nozzle. Foam agent that used in this experiment is 3% type of AFFF (Aqueous Film Forming Foam) solution. Experimental result showed the door opening effect was little. Fire extinguishing performance of foam agent mixture water mist was better than the plain water mist only.

• Journal of the Korean Society of Safety
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• v.28 no.6
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• pp.23-28
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• 2013

In order to improve extinguishing performance of water mist, many studies of additives have been conducted. In this study, viscosity agent which has the ability to improve extinguishing performance by adhering to the surface on fire was used and fluorine-free surfactant was also added to water to enhance water's wetting ability. This study aimed to verify optimal concentration of extinguishing of additives according to fire source and extinguishing performance by comparison with pure water. In case of wood crib fire, the results show that flame suppression and extinguishing time of sodium alginate 0.4 wt.% are 3.4 times and 2.2 times shorter than those of pure water in 0.2 MPa respectively. It seems that large amount of water adhere to surface on fire, thus cooling effect on surface was enhanced. Also water consumption of sodium alginate 0.4wt.% is up to 65% lower than that of pure water. In case of heptane fire, extinguishing time of cocobetaine 0.1 wt.% is 9.7 times shorter than that of pure water in 0.2 MPa. It is thought that because cocobetaine can block oxygen and suppress oil mist by making emulsion film on fire surface due to a low surface tension. On the other hand, water consumption of cocobetaine 0.1 wt.% is 92% lower than that of pure water.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.04a
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• pp.159-162
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• 2008

A standard fire extinguishing tester, with which we could conduct the fire extinguishing ability rating of a water-based fire extinguishing agent such as water and loaded stream, has been developed in this work. It could help us enhancing the efficiency and reliability of the fire extinguishing test of loaded streams, and at last increasing the productivity of fire protection related firms. Furthermore, our country could take the lead in making a new standard for the fire extinguishing test of loaded streams. As a result, it is expected that loaded streams could be improved by using it. In addition the standard fire extinguishing tester could be made moderately in our industry, and supplied at home and worldwide.

• Fire Science and Engineering
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• v.28 no.2
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• pp.20-25
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• 2014

In this study, the extinguishing performance evaluation of wetting agent for wood crib was conducted by using a scale model equipment that we designed. To confirm the optimal conditions of the experiment, a test was changed amount of fire extinguishing water and the number of timber. As a result, the discrimination of the fire extinguishing performance was seen only when 20 pieces of wood and the extinguishing water of 100 mL were used. After evaluating the extinguishing performance of domestic and foreign wetting extinguishing agents under these conditions, a reignition was occurred in only when we used water. In addition, the discrimination of extinguishing performance was seen through the temperature distribution according to the time of watering. Based on the results of this experiment, this study is expected to be able to use as a basis on presenting a method of optimized performance evaluation of wetting extinguishing agent.

• Journal of the Korean Society of Safety
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• v.34 no.3
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• pp.28-35
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• 2019

Dry water is a core-shell structured powder which comprises a very fine water core covered with hydrophobic silica particles. Recently, the dry water has attracted attention as a new type of fire extinguishing agents. However, characteristics of the dry water as a fire extinguishing agent have not been revealed until now. To our best knowledge, this is the first work to uncover effects of particle size of the dry water on the fire extinguishing performance. Pristine dry water, which has heterogeneous particle size distribution, was carefully separated by sieving method into three fractions which were a small size (ca. $110{\mu}m$) fraction, a medium size (ca. $220{\mu}m$) fraction and a large size (ca. $400{\mu}m$) fraction. Microscopic observations confirmed the effective separation of dry water's particle size. In extinguishing tests of wood cribs fire, the medium size dry water showed most excellent fire extinguishing performance, as compared to other dry waters having small (ca. $110{\mu}m$) and large (ca. $400{\mu}m$) particle size. The good performance of the medium size (ca. $220{\mu}m$) dry water may be attributed to the balance between cooling effect of the water core and smothering effect of the silica particles. It is also revealed that small size dry water has poor flowability than large size dry water.

• Fire Science and Engineering
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• v.23 no.3
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• pp.61-66
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• 2009

We carried out the water mist fire extinguishing experiments with the 3 kinds of foaming agents varied on the nozzle height. Test result showed that 2% AFFF (Aqueous Film Forming Foam) and 1% synthetic foaming agent for water mist system are the faster extinguishing time than the pure water mist and 3% AFFF solution. Additionally, the best fire extinguishing performance of pure water mist was shown at 3.5m nozzle height and that of the foaming agents shown at 4m nozzle height.

• Fire Science and Engineering
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• v.29 no.2
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• pp.13-19
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• 2015

Real scale fire tests was carried out for extinguishing performance evaluation of the wetting agent. The experiment was conducted in accordance with a Class A fire extinguishing test methods specified in the 'Type Approval of the Manual System Fire Extinguisher and Technical Standards of Test'. In addition, the subjects of this experiment were the wood flour and rice husk. Fire-fighting water, the three kinds of wetting agents used in the country and this study was used, was undertaken to determine a clear discrimination of the water and wetting agent. In the experimental results, it was confirmed that the internal temperature is maintained long time in the case of water. The internal temperature were rapidly lowered in the experiment of wetting agents. Therefore, the discrimination of extinguishing ability was confirmed by the temperature distribution in accordance with time. Based on the results of this experiment, this study is expected to be used as a underlying material on presenting a method of optimized performance evaluation of wetting extinguishing agent.

• Journal of the Korean Society of Safety
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• v.30 no.4
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• pp.79-85
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• 2015

Onboard fire extinguishing system is important to protect cargo and human lives and every oil tanker has foam type fire extinguishing system. Because of environmental problem, agent which contains materials such as Perfluorinated compounds are regulated and the development of the environmental friendly agent is required. The protein foam has less environmental pollution problem and has an excellent fire extinguish performance to oil fire. In the research, bivalency metal salts were added as stabilizer to increase fire resistance and stability of the foam. Ferrous sulfate, Iron chloride and Nickel chloride were used and to adjust to vessel, sea water was applied. As a stabilizer increased, the expansion ratio was raised. However 25% drainage time was decreased over 2.0 wt.% which is knowable that the foam brokes easily. The amount of generated foam was measured to check fluidity of foam and it appeared that when $FeSO_4$ 1.2 wt.% was added, the amount of generated foam reached large and also the 25% drainage time was high. To evaluate the fire extinguishing performance for oil fire, the small scale oil fire test was executed. When $FeSO_4$ 1.2 wt.% was added, fire extinguishing time was in its shortest which informs fluidity of foam and stability are important factors on fire extinguishing efficiency.

• Journal of the Korean Society of Safety
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• v.24 no.5
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• pp.21-27
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• 2009

Effective way of cooking oil fire extinguishment is using water mist system which has cooling and smothering effects. Low pressure water mist system has advantage because it is compatible with existing sprinkler systems. To increase the effectiveness of low pressure water mist system, additives can be used which increase the momentum of water particle and the chemical effect. In this experiment, aqueous film forming form(AFFF) agent is used as additive and the effect of additive concentration and water pressure are experimented. For the extinguishment of cooking oil fire such as soybean and olive oils, AFFF agent is effective and can decrease the fire extinguishing time and water consumption.