• 한국안전학회지
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• 제16권4호
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• pp.103-108
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• 2001

Explosive limit is one of the major physical properties used to determine the fire and explosion hazards of the flammable substances. Explosive limits are used to classify flammable liquids according to their relative flammability. Such a classification is important for the safe handling of flammable liquids which constitute the solvent mixtures. Explosive limits of all compounds and solvent mixtures can be calculated with the appropriate use of the fundamental laws of Raoult, Dalton, Le Chatelier and activity coefficient models. In this paper, Raoult,s law and van Laar equation(activity coefficient model) are shown to be applicable for the prediction of the explosive limits in the flammable ethylacetate-toluene system. The values calculated by the proposed equations were a good agreement with literature data within a given percent. From a given results, by the use of the proposed equations, it is possible to predict explosive limits of the other flammable mixtures. It is hoped eventually that this method will permit the estimation of the explosive Properties of flammable mixtures with improved accuracy and the broader application for other flammable stances.

• 한국안전학회지
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• 제12권3호
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• pp.76-82
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• 1997

Flash points ire used to classify flammable liquids according to their relative flammability. Such a classification is important for the safe handling of flammable liquids which constitute the solvent mixtures. MRSM(modified response surface methodology)-1 and MRSM-2 models we suggested for the prediction of the flash points in the flammable ternary system. By means of this methodology, it is possible to predict the flash points of the flammable mixtures system using computer graphics in the triangular coordinate for the ternary system. The proposed methodology(MRSM) has been tested and compared successfully with previously reported flash points in journal for the ternary system.

• 한국가스학회지
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• 제10권1호
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• pp.19-25
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• 2006

폭발한계는 가연성물질의 화재 및 폭발 위험성을 결정하기 위해 사용되는 중요한 연소 특성치 가운데 하나이다. 폭발한계는 상대 연소에 따라 가연성물질을 구분하는데 사용된다. 이런 구분은 가연성물질의 안전한 취급, 처리, 수송을 위해서 중요하다. 본 연구에서는 가연성혼합물의 구성하는 각 순수성분의 연소열과 기상 조성을 이용하여 폭발한계를 예측하였다. 제시된 방법론에 의한 계산값은 적은 오차범위에서 문헌값과 일치하였다. 따라서 제시된 결과로부터 가연성혼합물의 폭발특성치 예측 방법과 다른 가연성혼합물의 폭발한계 예측에 폭넓게 적용되기를 기대한다.

• 한국안전학회지
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• 제7권3호
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• pp.53-59
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• 1992

A general theory is developed which enables closed-cup flash points of mixtures of flammable and non-flammable liquid to be estimated from a knowledge of a certain properties of flammability diagram by thermodynamic method. The estimated equations is shown the effect of both the flame inhibiting properties of the vapor of the non-flammable component and the relative volatility of that component. The vapor phase flame inhibition effect results in a even greater elevation of flash points than the rotative volatility of that component. Especially in cases of similar vapor phase flame inhibition of the non-flammable component, the rotative volatility is affected greater elevation of flash points(extinguishing effect).

• 한국안전학회지
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• 제20권3호
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• pp.91-97
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• 2005

The research on the explosive limits is one of fundamental fields of combustion process, and information on the explosive limits of mixture of fuel and oxidant, with or without additives, is very important for the prevention in industrial fire and explosion accidents. Explosive limits of all compounds and solvent mixtures can be calculated with the appropriate use of the fundamental laws of Raoult, Batten, Le Chatelier and MRSM(modified response surface methodology) model. In this study, the reference values of lower explosive limits(LEL) of the ethanol+toluene+ethylacetate system were compared with the calculated values by using the solution thermodynamics and the MRSM model, respectively. The values calculated by the proposed equations were a good agreement with literature data within a few percent. By means of this methodology, it is possible to evaluate reliability of experimental data of the lower explosive limits of the flammable mixtures. Also, from given results, it is possible to predict explosive limits of the other flammable liquid mixtures used in the chemical process by the use of the proposed equations.

• 한국화재소방학회논문지
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• 제15권3호
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• pp.14-20
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• 2001

인화점은 가연성물질의 화재 및 폭발의 잠재위험성를 결정하는 데 가장 중요한 기초적인 특성치 가운데 하나이다. 인화점의 구분은 혼합용제를 구성하는 가연성액체를 안전하게 취급하기 위해서 매우 중요하다. 모든 인화점 거동의 기초는 증기압과 폭발한계이다. 가연성혼합용제의 인화점은 라울의 법칙, 달톤의 법칙, 르샤틀리에 법칙 그리고 활동도계수 모델을 사용함으로서 계산할 수 있다. 본 연구에서는 가연성 3성분계의 하부인화점의 문헌값을 라울의 법칙과 MRSM 모델에 의해 계산된 값과 비교하였다. 3성분계의 하부인화점의 자료는 라울의 법칙과 MRSM 모델에 의해 예측된 값과 거의 일치하였다. 제시한 방법론에 의해 가연성혼합용제의 인화점 실험자료의 신뢰도를 평가하는 것이 가능하다.

• 한국화재소방학회논문지
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• 제13권1호
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• pp.11-19
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• 1999

인화점은 일반적으로 가연성액체의 화재 및 폭발의 위험지수로써 사용된다. 인화점의 구분은 혼합용제와 같은 가연성액체를 안전하게 취급하기 위해서 매우 중요하다. 순수성분 및 혼합용제의 인화점은 라울의 법칙, 달톤의 법칙, 르 샤틀리에 법칙 그리고 활동도계수 모델을 사용함으로써 계산할 수 있다. 본 연구에서는 가연성 2성분계인 메칠에칠케톤과 톨루엔계의 하부인화점과 상부인화점의 실험자룔르 라울의 법칙과 van Laar식에 의해 계산된 값과 비교하였다. 순수물질의 실험자료는 증기압과 폭발한계에 의해 계산된 예측값과 일치하였다. 메칠에칠케톤과 톨루엔계의 하부인화점의 실험자료는 라울의 법칙에 의해 예측된 값과 일치하였고, 상부인화점의 실험자료는 van Laar식에 의해 예측된 값과 일치하였다. 따라서 제시한 방법론에 의해 가연성혼합용제의 인화점 실험자료의 신뢰도 평가가 가능하다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 E
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• pp.1819-1823
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• 1997

When flammable gases are mixed with air or oxygen in the explosion concentration range and are ignited by sufficiently large electrostatic discharge energy, they may explode causing severe disaster in workplaces. The minimum ignition energy (MIE) of single gas-air mixtures has been already investigated by many researchers, but the MIE of mixtures of more than three substances is not examined yet. The purpose of this study is to investigate the MIE of several three-component gas mixtures experimentally. The result of our experiment shows that the MIE of some gas mixtures is quite different from that we expected based on the characteristics of individual gas-air mixture.

• 한국안전학회지
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• 제27권4호
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• pp.26-32
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• 2012

With a progress of electrical and electronic technology, radio-frequency including high frequency components are widely to various industrial installations. Some of them are used in hazardous locations where explosive or flammable gases exist. As a result, ignition of such gases may be induced by a spark discharge when the radio frequency circuits are switched on or off. The purpose of this study is to investigate the ignition hazards of some kind of flammable mixtures based on the IEC 60079-11 publication. In this experiment, we used a high frequency resistive circuit which consists of a co-axial cable, a 20 ${\Omega}$, 30 ${\Omega}$, 40 ${\Omega}$ and 50 ${\Omega}$ resistor and two kind of power amplifier with frequency range up to almost 1 MHz and 50 MHz. Experimental results show that the ignition of the acetyleneair, ethylene-air mixtures and methane-air mixtures due to spark discharge depends primarily on the frequency of the power source in the resistive circuit the minimum ignition voltage increases gradually with the increase of the frequency.

• 설비공학논문집
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• 제5권3호
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• pp.217-225
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• 1993

Nonflammable mixtures of flammable and nonflammable refrigerants are possible as substitute refrigerants for use in domestic heat pumps and refrigerators. Refrigerant leakage from such a system is of paramount concern since it is possible that the resulting mixture composition remaining in system will reside in the flammable range. This paper presents a simulation of a leakage process of refrigerant mixtures. Idealized cases of isothermal leakage process are considered in this study representing a slow leak. Simulation is performed for selected composition of binary and ternary refrigerant mixture; R-32/134a and R-32/125/134a. Mixture compositions with respect to percentage leak of original charge are presented. In isothermal leakage process, both vapor and liquid compositions of more volatile refrigerant decrease during vapor and liquid leak, but the total composition of this component decreases during vapor leak and increases during liquid leak. Vapor and liquid compositions are determined depending on the vapor-liquid equilibrium relation of the refrigerant mixture. The refrigerant mixture left in the system can go to a nonflammable direction relying on which component in the mixture is flammable.