• Title/Summary/Keyword: Flammable

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Measurement and Prediction of Flash Points of Acetic Acid-Formic Acid System using Cleveland Open Cup Apparatus (Cleveland 개방식 장치를 이용한 Acetic acid+Formic acid 계의 인화점 측정과 예측)

  • Ha, Dong-Myeong;Lee, Sungjin
    • Journal of the Korean Institute of Gas
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    • v.17 no.6
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    • pp.67-72
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    • 2013
  • The flash point is the lowest temperature at which there is enough concentration of flammable vapor to form an ignitable mixture with air. The flash point is a major physical property used to analyse the fire and explosion hazards of a flammable liquid solution. The flash point data for pure components are easily available in several literature. But the flash points of the flammable binary solutions appear to be scarce in the literature. The objective of this study is to measure and estimate the flash point of acetic acid-formic acid system. Cleveland open cup tester was used to measure the flash point. The experimental data were compared with the values estimated by the Raoult's law and the optimization methods based on van Laar and Wilson equations. As a result, the estmated values by optimization methods were found to be better than those based on the Raoult's law.

Investigation on the Field Application of the Flammable Limit of Vaporized Gasoline (휘발유 유증기 폭발범위의 현장 적용성에 관한 연구)

  • Kang, Jung Ki;You, Woo Jun;Choi, Don-Mook
    • Fire Science and Engineering
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    • v.29 no.4
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    • pp.73-80
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    • 2015
  • In this study, the conditions of explosion range of gasoline, which is used as combustion improver, are experimentally analyzed. Two types of compartment, which is the small scale ($0.5m{\times}0.5m{\times}1.0m$) and the middle scale ($0.5m{\times}0.5m{\times}1.0m$), are mocked-up and the auto-control systems are installed in order to measure the vaporized gasoline and the moment of pressure, ignition time and maximum pressure. In case the maximum flammable limit of gasoline is up to 22.4 Vol% not the generalized range of 1.4~7.6 Vol% when nichrome igniter of $700^{\circ}C$ is used. These results can be appled to the analytical prediction of fire identification in the field of explosion.

Measurement and Prediction of the Lower flash Point for n-Propanol+n-Decane System Using the Tag Open-Cup Apparatus (Tag 개방식 장치를 이용한 n-Propanol+n-Decane 계의 하부인화점 측정 및 예측)

  • Ha Dong-Myeong
    • Journal of the Korean Society of Safety
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    • v.20 no.2 s.70
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    • pp.162-168
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    • 2005
  • The lower flash points for the n-propanol+n-decane flammable mixture were measured by the Tag open-cup apparatus(ASTM D 1310). The experimental results of mixture exhibited the lower flash point than those of pure component in the flash point versus composition curve. The experimental value of the minimum flash point is $27^{\circ}C$ at a mole fraction of n-propanol of 0.71, and the flash point of n-propanol was $28^{\circ}C$. The experimentally obtained data were compared with the values that had been calculated by use of the prediction model, which assumes an ideal solution, and the flash point prediction models based on the van Laar equation were used to estimate the activity coefficients. The predictive curve based on an ideal solution deviated from the experimental data for this system. The experimental results demonstrate a close agreement with the predicted curves, which used the van Laar equation. The average absolute deviation(A.A.D.) from using the van Lau equation is $0.83^{\circ}C$. The methodology proposed here in this paper can thus be applied to incorporate an inherently safer design for chemical processes, such as determining safe storage and handling conditions for flammable solutions.

Effects of Preferential Diffusion on Downstream Interaction in Premixed $H_2$/CO Syngas-air Flames (상호작용하는 $H_2$-CO 예혼합 화염에서 $H_2$선호확산의 영향에 관한 수치적 연구)

  • Oh, Sanghoon;Park, Jeong;Kwon, Ohboong
    • Journal of the Korean Society of Combustion
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    • v.17 no.3
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    • pp.17-29
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    • 2012
  • The effects of strain rate and preferential diffusion of $H_2$ on flame extinction are numerically studied in interacting premixed syngas-air flames with fuel compositions of 50% $H_2$ + 50% CO and 30% $H_2$ + 70% CO. Flame stability diagrams mapping lower and upper limit fuel concentrations at flame extinction as a function of strain rate are examined. Increasing strain rate reduces the boundaries of both flammable lean and rich fuel concentrations and produces a flammable island and subsequently even a point, implying that there exists a limit strain rate over which interacting flame cannot be sustained anymore. Even if effective Lewis numbers are slightly larger than unity on extinction boundaries, the shape of the lean extinction boundary is slanted even at low strain rate, i.e. $a_g=30s^{-1}$ and is more slanted in further increase of strain rate, implying that flame interaction on lean extinction boundary is strong and thus hydrogen (as a deficient reactant) Lewis number much less than unity plays an important role of flame interaction. It is also shown that effects of preferential diffusion of $H_2$ cause flame interaction to be stronger on lean extinction boundaries and weaker on rich extinction boundaries. Detailed analyses are made through the comparison between flame structures with and without the restriction of the diffusivities of $H_2$ and H in symmetric and asymmetric fuel compositions. The reduction of flammable fuel compositions in increase of strain rate suggests that the mechanism of flame extinction is significant conductive heat loss from the stronger flame to ambience.

Prediction of the Detonation Limit of the Flammable Gas and Vapor (가연성가스와 증기의 폭굉한계 예측)

  • Ha, D.M.;Yoo, H.S.;Kang, S.H.;Park, D.J.;Jeong, J.Y.;Lee, M.H.;Choi, W.Y.;Han, S.H.
    • 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.

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Study on the Limiting Oxygen Index of Curtain Exposed to High Temperature (고온에 노출된 커튼의 한계산소지수에 관한 연구)

  • Kim, Hwang-Jin
    • Fire Science and Engineering
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    • v.32 no.5
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    • pp.1-5
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    • 2018
  • Curtains are used for shading in windows. Since most curtains are made of flammable materials and are installed vertically, curtains can be an important factor in fire spreading. Accordingly, it is important to predict fire behaviors in studies on the combustion characteristics of flammable interior decorations, such as curtains. In this study, to analyze the combustion characteristics of six kinds of curtains, which are widely used interior decorations, the oxygen index was measured at room temperature and higher temperature. As a result of the experiment, the oxygen index at higher temperature of all specimens was about 3%~7.5% lower than that at room temperature and difference of 0.2% of oxygen index show big differences in combustion phenomenon of specimens. Therefore, when flame retardancy is evaluated with the oxygen index value of flammable interior decorations, the oxygen index value at higher temperature should be sufficiently considered.