• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.04a
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• pp.164-164
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• 2013

화학 관련 산업은 고온, 고압뿐만 아니라 반응성이 큰 물질들을 사용하는 복잡한 공정으로 이에 맞는 안전기술이 요구된다. 산업 현장에서 취급하고 있는 각종 화학물질의 안전관리를 어렵게 하는 이유는 취급하는 물질의 화재 및 폭발 특성치에 관한 자료가 부족하거나 정확하지 않은 연소 특성치를 사용하기 때문이다. 가연성물질의 연소현상 가운데 하나인 자연발화는 가연성 혼합기체에 열 등의 형태로 에너지가 주어졌을 때 스스로 타기 시작하는 산화현상으로, 주위로부터 충분한 에너지를 받아서 스스로 점화할 수 있는 최저온도를 최소자연발화온도(AIT : Auto ignition Temperature)라고 한다. 최소자연발화온도는 가연성 액체의 안전한 취급을 위해 중요한 지표가 된다. 순수물질의 최소자연발화온도를 문헌들에서 비교하면, 동일 물질인데도 불구하고 문헌에 따라 다른 최소자연발화온도가 제시되고 있다. 따라서 사업장에서 사고를 예방하기 위해서는 정확한 연소 특성 자료를 이용해야 해야 한다. 그러나 문헌에 제시된 대부분의 자료들은 과거 표준장치 및 자체 제작된 장치 등을 사용해서 얻은 결과이므로, 최근에 고안된 표준 장치를 이용한 결과가 매우 유용한 자료가 될 것으로 본다. 본 연구에서는 자연발화온도를 측정하는데 있어서 최근에 고안된 표준장치인 ASTM E659장치를 이용하여 n-Propanol과 Formic acid 혼합물의 최소자연발화 온도를 측정하였다. n-Propanol과 Formic acid 혼합물의 최소자연발화 온도는 화학 관련 산업 공정에서 매우 중요한 자료가 될 것이다.

• Fire Science and Engineering
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• v.26 no.6
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• pp.7-14
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• 2012

This paper is to develop analytical techniques of flammable liquids which have been used for accelerating fire in accidental fires and arsons. We tested the temperature distribution of ceiling, fire patterns on the floor, and existence of flammable liquids and a check with GC/MS about flammable liquids comparing with papers, newspapers, and clothing. Research findings are as follows. The temperature of ceiling is influenced by flame. So gasoline and thinner was observed that combustible materials would be burned by flame. The fire patten on the floor was observed that flammable liquids had specialized pattern comparing combustible materials. When combustible materials on the PVC (Polyvinyl chloride) floor was burned, they didn't react to the gas detector. But flammable liquids had opposite results. After 7 days, we identified components of fire residues with the GC/MS (Gas Chromatography/Mass Spectrometry) about existence of flammable liquids and got components of flammable liquids. Fire investigation is a complicated processes. But we understand characteristics of materials, need detail investigations, and use the GC/MS to analyse flammable materials.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.1
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• pp.11-19
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• 2015

We present the results of a multi-material numerical investigation of the propagation of a combustible gas mixture detonation in narrow metal tubes. We use an experimentally tuned one step Arrhenius chemical reaction and ideal gas equation of state (EOS) to describe stoichiometric $H_2-O_2$ and $C_2H_4-O_2$ detonations. The purely plastic deformations of copper and steel tubes are modeled using the Mie-Gruneisen EOS and Johnson-Cook strength model. To precisely track the interface motion between the detonating gas and the deforming wall, we use the hybrid particle level-sets within the ghost fluid framework. The calculated results are validated against the experimental data because the results explain the process of the generation and subsequent interaction of the expansion wave with the high-strain-rate deformation of the walls.

• Analytical Science and Technology
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• v.27 no.3
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• pp.167-171
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• 2014

Hydrofluoric acid (HF), a typical inorganic acid, has been used in the industry for its various usage and classified as the toxic compound, because it can cause the pneumonia and pulmonary edema when it was exposed to respiratory organs. The official environmental analytical method for fluorine and its compound in waste has not been developed. For this reason, we have faced some problem to treat the contaminated wastes by the HF leakage from industrial process. In this study, prepared for analytical method for combustible waste (crop, trees, etc.) generated from HF leaking accident and to be applied as the official analytical method for fluorine contaminated waste when the fluorine and its compound will be regulated as a hazardous material by the waste management law later.

• Journal of the Korean Institute of Gas
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• v.1 no.1
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• pp.1-6
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• 1997

In case of using the electrical apparatus in the hazardous atmosphere which exist flammable gas mixtures, There is a dangerosity of gas explosion accident by the electrical spark. The most general method to prevent the explosion by the spark is to use the flame-proof type electrical apparatus to isolate the ignition source. from the flammable atmosphere. But actualy it is impossible to isolate the ignition sources from the atmosphere. So it was needed to find the safe gap which prevent ignition of flammable atmosphere by transmission of flame or heat when a flammable gas mixture exploded inside the apparatus. In this study we tried to find the maximum experimental safe gap(MESG) of $H_2$-air, and $CH_4$-air mixtures by using the 8 litre spherical vessel with 25mm flange. The experiment parameter were ignition position, concentration and initial pressure before explosion. From the experiment the ignition position was affected to the MESG. MESG value was minimum near the stoichiometric concentration of gas mixtures, and according to the increase of initial pressure MESG was decreased.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.10
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• pp.726-734
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• 2007

In this study, lower flammability limits (LFLs) of three hydrocarbon refrigerants (R600a, R290, R1270) and two hydrofluorocarbon refrigerants (R152a, R32) and DME (RE170) are measured by the method proposed by ASTM E681-04 Standard. Flammability tests are carried out at three temperatures of $23^{\circ}C,\;60^{\circ}C\;and\;100^{\circ}C$ and relative humidity 50%. Test results show that the present data for isobutane and propane obtained at $23^{\circ}C$ are similar to those found in the literature, confirming indirectly the reliability of the present test method and facility. For propylene, R152a, and R32, LFLs found in the literature differ considerably. Especially, the deviation of LFL of propylene is more than 30% among the literature data. The present data for propylene, R152a, and R32 agree with either of the data sets available. As the temperature increases from $23^{\circ}C\;to\;100^{\circ}C$, LFLs of all refrigerants tested decrease. LFLs of most refrigerants tested in this study at $60^{\circ}C$ decrease by $0.1{\sim}0.3%$ as compared to those at $23^{\circ}C$. Also LFLs of most refrigerants tested in this study at $100^{\circ}C$ decrease by $0.1{\sim}0.3%$ as compared to those at $60^{\circ}C$.

• Nuclear Engineering and Technology
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• v.23 no.3
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• pp.352-362
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• 1991

Recent popular trends in pressurized water reactor(PWR) fuel management are to extend the cycle length and to employ the low-leakage core designs for the optimal utilization of the uranium resources. In control strategy incorporated with the fuel management, turnable absorbers are required to control the power peaking and to ensure a negative moderator temperature coefficient during reactor operation. In this study, the nuclear characteristics and the optimal allocation of gadolinium-poisoned rods within the fuel assembly are considered using KWU SAV 79 A Code Package. First, analyses are carried out to compare the nuclear characteristics of the fuel assemblies contain-ing WABA(Wet Annular Burnable Absorber) and Gadolinium burnable absorbers respectively. The analyses show that the gadolinium-bearing fuel assembly has peculiar depletion characteristics ensuing from the very large thermal neutron absorption cross section. Peculiar characteristics of gadolinium provide basis for the optimal allocation of Gd rods in fuel assembly. Second, the methodology of an optimal allocation of gadolinium-poisoned rods within the fuel assembly is developed and applied to some nuclear designs.

• Fire Science and Engineering
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• v.26 no.2
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• pp.53-58
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• 2012

In this study fire control characteristics for inflammable materials of water curtain system are experimentally analyzed. Heat release rate for pinewood and gasoline was calculated using Room Corner Tester (RCT) and fire test apparatus for water curtain system is manufactured. Nozzles (180 degree of injection angle, 8.2 mm of orifice diameter) are installed at the nearby ceiling of place at 5 m distance from fire originate and temperature profile as well as transmission are obtained from the fire experiment of pinewood and gasoline in the water curtain system. Based on the results, parameters of engineering importance for fire control characteristics of water curtain system such as generation of high temperature smoke and thermal phenomena of fluid flow by injection nozzle are identified.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.04a
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• pp.131-134
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• 2008

In this study, the lower detonation limits(LDL) and the upper detonation limits(UDL) of the flammable substances predicted with the appropriate use of the heat of combustion and the stoichiometric coefficient. The values calculated by the proposed equations were a good agreement with literature data within a few percent. From a given results, It is to be hoped that this methodology will contribute to the estimation of the detonation limits of for other flammable substances.

• Fire Science and Engineering
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• v.27 no.5
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• pp.64-69
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• 2013

The autoignition temperatures (AITs) of solvent mixture was important index for the safe handling of flammable liquids which constitute the solvent mixtures. This study measured the AITs and ignition delay time for n-propanol and formic acid system by using ASTM E659 apparatus. The AITs of n-Propanol and Formic acid which constituted binary system were $435^{\circ}C$ and $498^{\circ}C$, respectively. The experimental AITs of n-propanol and formic acid system were a good agreement with the calculated AITs by the proposed equations with a few A.A.D. (average absolute deviation). And n- Propanol and formic acid system was shown the minimum autoignition temperature behavior (MAITB).