• Fire Science and Engineering
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• v.30 no.5
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• pp.1-8
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• 2016

Safety management in hazardous areas with potentially explosive gas atmospheres (here in after referred to as hazardous areas) in large scale facilities dealing with combustible or flammable materials at home and abroad is very important (significant) for the coexistence of the company and local society based on business continuity management (BCM) and reliance. For the safety management in hazardous areas, two systems are mainly used: (1) the control system for the prevention of combustible or flammable substances and (2) the explosion proof system for the elimination of ignition sources when flammable gases are leaked to inhibit the transition to fire or explosion accidents. While technology and regulations on explosion proof facilities or devices for electrical ignition sources are well developed and defined, those for thermal ignition sources need to be more developed and established. In this study, the internal combustion engine in hazardous areas was investigated to determine the risk of ignition. For this purpose, document searches were conducted on the relevant international standards and accidents cases and risk analysis reports. In addition, this study assessed the application cases of the diesel engine's safety equipment, such as spark arresters regarding the site of process safety management (PSM) system in central Korea. To practically apply these results to the hydrocarbon industry, the safety management method for explosion prevention in hazardous areas was provided by risk identification for ignition sources of internal combustion engines, such as diesel engines.

• Journal of Korean Institute of Fire Investigation
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• v.11 no.1
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• pp.139-144
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• 2007

The fires were occasionally occurred by the quicklime, used in soil conditioners and stall disinfectant, in the stables and shed especially during the rainy season. Accordingly, we observed that spontaneous ignition by the exothermic reaction was happened through the revival experiments. As a results of revival experiments, we confirmed that fire had been occurred by exothermic energies in the case of heat accumulation.

• Fire Science and Engineering
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• v.26 no.3
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• pp.35-39
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• 2012

This paper analyzes the combustion diffusion pattern when a water purifier is artificially ignited outside and inside in order to provide data to examine the cause of fire of a water purifier damaged by fire. The analysis result of the combustion diffusion pattern of a water purifier shows that the combustion diffused at a higher speed when it was ignited inside the purifier than when ignited outside. It took approximately 360 seconds for the water purifier to be half-burned when ignited on the outside, and approximately 180 seconds when ignited from inside. That is, it is thought that the internal combustion speed is higher because the internal ignition causes the generated heat to be accumulated and radiated instantly. It was observed that the water purifier damaged by fire caused by external ignition showed a uniform carbonization pattern and the carbide burned down at the bottom were gradually deposited. The water purifier damaged by internal ignition showed a relatively clear boundary of carbonized surface, which formed a V-pattern. The difference in the combustion patterns presents an objective base from which to determine where the fire started. By the time the purifier was half-burned by fire, the built-in fuse had not melted and the power supply protection device did not operate. In addition, as was found in the case of the fuse damaged by a general fire, carbonization occurred at the metal holder, and it is thought that this fact may be used as a basis from which to determine the cause of a fire.

• Fire Science and Engineering
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• v.27 no.2
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• pp.11-17
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• 2013

For the safe handling of n-undecane, the lower flash points and the upper flash point, fire point, AITs (auto-ignition temperatures) by ignition delay time were experimented. Also lower and upper explosion limits by using measured the lower and upper flash points for n-undecane were calculated. The lower flash points of n-undecane by using closed-cup tester were measured $59^{\circ}C$ and $67^{\circ}C$. The lower flash points of n-undecane by using open cup tester were measured $67^{\circ}C$ and $72^{\circ}C$, respectively. The fire point of n-undecane by using Cleveland open cup tester was measured $74^{\circ}C$. This study measured relationship between the AITs and the ignition delay times by using ASTM E659 apparatus for n-undecane. The experimental AIT of n-undecane was $198^{\circ}C$. The estimated lower and upper explosion limit by using measured lower flash point $59^{\circ}C$ and upper flash point $83^{\circ}C$ for n-undecane were 0.65 Vol.% and 2.12 Vol.%.

• Fire Science and Engineering
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• v.21 no.3
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• pp.41-46
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• 2007

The combustion characteristics of surface forest fire fuels was analysed using variable external irradiation level. The characteristics such as ignition time, ignition temperature, critical heat flux and mass loss rate were measured. Fuel samples were exposed to incident heat fluxes from 8 to $50\;kW/m^2$. For the measurement of various combustion characteristics, the size of specimen holder was $100\;mm{\times}100\;mm{\times}12\;mm$ and the fuel samples grinded by electric mill were the fallen leaves of Quercus variabilis and Pinus densiflora. As results, the occurrence of ignition is possible to the heat flux more than $9\;kW/m^2$. The fuel of Pinus densiflora keeps its high temperature longer than that of Quercus variabilis during the combustion process. The results of measurement shows that the maximun and average mass loss rate of Quercus variabilis larger than that of Pinus densiflora.

• Journal of the Korean Society of Safety
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• v.8 no.4
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• pp.107-113
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• 1993

Small rectangular explosion chamber of its size 25cmX25cmX32cm with a circular bursting diaphram at the top was used to study the mechanism of gas explosion to fire transition phenomena, the process of ignition of solid combustibles during a gas explosion. To visulize the explosion to fire transition phenomena, transparent acryl window and high speed camera system were used. The test piece of solid combustible in this experiments was a 5cm$\times$5cm square sheet of newspaper which was placed in the explosion chamber filled with a LPG-air mixture. The mixture was ignited by an electric spark at the center of the chamber. Explosion to fire transition phenomena and the behavior of out flow and in flow of gas through the opening yielded by bursting the diaphram was visualized with shlieren system and without shlieren system. Diameter of a bursting dlaphram at the top of the explosion chamber was varied 5cm, 10cm, and 15cm, and the position of test piece were varied with 6 point. Explosion pressure was measured with strain type pressure transducer, and the weight difference of the test piece before and after each experimental run was measured. By comparing the weight difference of solid combustibles before and after the experiment and the behavior of out flow and inflow of gas after explosion, it was found that the possibility of ignition was depends on the LPG-air mixture concentration and the exposure period of test piece to the burnt gas. Test result of this experiments it was found that the main factor of this phenomena are that heat transfer to the test piece, and the pyrolysis reaction of test piece. Based on the results, the mechanism of the explosion to fire transition phenomena were inferred ; gas explosion- heat transfer to solid combustibiles ; pyrolysis reaction of solid combutibles : air inflow ; mixing of the pyroly gas with air ignition.

• Journal of the Society of Disaster Information
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• v.18 no.3
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• pp.574-580
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• 2022

Purpose: As corn oil is semi-drying oil, it has more double bonds than non-drying oil and is easier to combine with oxygen. In addition, among the causes of spontaneous ignition, accidents caused by oil-soaked cloths due to oxidative heat are gradually increasing. Therefore, the purpose of this study is to understand the characteristics of spontaneous combustion according to the number of towels and the amount of corn oil at 65℃. Method: After setting the test temperature to 65℃, 25ml, 50ml, 75ml of corn oil per towel was sprayed. The central temperature of the sample rises above the set temperature. It was determined, and when the central temperature of the sample became similar to the set temperature, it was determined as non-igniting. Result: After evenly distributing 25ml of corn oil per towel, as a result of the experiment, 5 towels did not ignite, and 10 and 15 towels ignited. Also, as a result of an experiment using 50ml and 75ml of corn oil per towel, spontaneous ignition occurred when the number of towels was 5, 10, or 15 sheets. Conclusion: Even a small amount can cause a fire if the conditions for spontaneous ignition are met.

• Journal of the Korean Society of Safety
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• v.29 no.2
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• pp.89-97
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• 2014

This study analyzed various possibilities of flash fire which could occur in a variety of combats, in order to predict that of flash fire of combat system armor using Autodyn program. The possibility was judged by the temperature distribution of fuels, which was caused by the impact of parts of fuel systems through an armor, in the event of getting shot by external ammunition. Diverse variables could affect the possibility of flash fire: external ammunition(Type A: penetration 570 mm, Type B: penetration 410 mm), fuels(Gasoline, Diesel, Kerosene), the thickness of an armor(100, 200, 300, 400, 500 mm), the gap of a fuel tank and an armor(45, 95, 145, 195, 245, 295 mm). As a result, when an armor was 20 mm think, the temperature of 3 fuels ranged like this: Gasoline 372~387 K, Diesel 442~408 K, Kerosene 384~395 K. Although they made a little difference among them, they all didn't reach their ignition points. When an armor was 200 mm think, each fuel reached the maximum temperature, not reaching its ignition points as well. The thicker an armor was, the lower the temperature got. When Type B ammunition was used, the temperature of fuels went up 19~59 K higher than Type A was used. In the case that the gap of fuel tank and an armor was 20 mm thick, the temperature distribution of Gasoline showed 389~450 K, the maximum temperature appeared in the gap of 145 mm, and the minimum temperature 295 mm. For Type B, the temperature distribution of fuels ranged 386~401 K, the maximum temperature appeared in the gap of 245 mm, and the minimum temperature 45 mm. There was no significant difference between two cases, and neither of them reached its ignition point. Accordingly, as the tested fuels of combat systems didn't reach their ignition points, it is thought that the possibility of flash point of an armor is low.

• Fire Science and Engineering
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• v.27 no.6
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• pp.89-96
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• 2013

The purpose of this study is to check the fire origin and cause of the fire by observing the shape of the flame propagation in air-conditioner indoor unit through the fire tests. We supposed that the flame is spread from the surroundings to the top of the air-conditioner and ignited on top of the air-conditioner with n-heptane. And then repeated this experiment twice under the same conditions. After the ignition, refrigerant filled in air-conditioner and lubricating oil exploded with large explosion and flame having high temperature and pressure belched out rapidly due to bursting refrigerant pipe linked air-conditioner between 734 seconds and 559 seconds. After result of checking the combustion residue we found that almost all of that was lost except a part of the evaporator, motor and metal. The position of short-circuit traces of wiring for the air-conditioner ignited itself is similar to that of fire damage by external flame. Therefore, we verified that it is not certain to determine the ignition cause and point by only the shape of the combustion residues.

• Fire Science and Engineering
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• v.25 no.3
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• pp.107-112
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• 2011

We have considered the fire hazard by the static in anti-static film manufacturing factory on this study. Solvents that the flash point as ethanol, methanol and iso-propyl alcohol is low are used on the manufacturing process of anti-static film, and the minimum ignition energy of these solvents is ignited easily despite less discharge energy form 0.16 mJ to 0.65 mJ. After the static electric potential produced on each of the manufacturing plants was measured, electric potential on films of paste board is measured form 17 kV to 20 kV. But this exceeds 5 kV, which is electrifiable of objective of nonconductor for fire & explode protection. Therefore, We figure out the fire hazard was high by a static discharge in anti-static film manufacturing factory.