• Title, Summary, Keyword: explosive limit

Search Result 62, Processing Time 0.03 seconds

A Study on the Explosion Characteristics of City Gas (도시가스의 폭발 특성에 관한 연구)

  • 최재욱;목연수;박승호
    • Journal of the Korean Society of Safety
    • /
    • v.16 no.4
    • /
    • pp.109-114
    • /
    • 2001
  • Explosive characteristics of the city gas were determined by using the gas explosion apparatues. The explosive range is determined between lower explosive limit of 5.0% and upper explosive limit of 15.3% at atmosphere and even though the oxygen concentration is decreased, lower explosive limit is not changed, but upper explosive limit is rapidly decreased. The minimum oxygen for combustion is determined 10%. The maximum explosion pressure is determined 5.72$\textrm{cm}^2$ and the maximum rate of explosion pressure rise is oxygen concentration of 12% to determined 160.12$\textrm{cm}^2{\cdot}$sec.

  • PDF

Prediction of Temperature Dependence of Lower Explosive Limits for Paraffinic Hydrocarbons (파라핀족탄화수소의 폭발하한계의 온도의존성 예측)

  • 하동명
    • Journal of the Korean Society of Safety
    • /
    • v.15 no.3
    • /
    • pp.71-77
    • /
    • 2000
  • The aim of this study is to investigate the temperature dependence of the lower explosive limit(LEL) at elevated temperature. The temperature dependence of the lower explosive limit is one of the significant indices of flammability and combustibility. By using the literature data, the new equations for predicting the temperature dependence of the lower explosive limits for paraffinic hydrocarbons are proposed. The values calculated by the proposed equations were a good agreement with the literature data. It is hoped eventually that this proposed equations will support the use of the prediction for the lower explosive limit and the flash points of the flammable mixtures.

  • PDF

A Study on Explosive Limits of Flammable Materials - Explosive Limits of Flammable Binary liquid Mixture by Liquid Phase Compositions - (가연성물질의 폭발한계에 관한 연구 - 액상 조성에 의한 가연성 2성분 액체혼합물의 폭발한계 -)

  • 하동명
    • Journal of the Korean Society of Safety
    • /
    • v.16 no.4
    • /
    • pp.103-108
    • /
    • 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.

  • PDF

Risk Assessment of Fire and Explosion of Methane (메탄의 화재 및 폭발 위험성 평가)

  • Ha Dong-Myeong
    • Journal of the Korean Institute of Gas
    • /
    • v.9 no.2
    • /
    • pp.1-7
    • /
    • 2005
  • The thermochemical parameters for safe handling, storage, transport, operation and process design of flammable substances are explosive limit, flash point, autoignition temperature, minimum oxygen concentration, heat of combustion etc.. Explosive limit and autoignition temperature are the major physical properties used to determine the fire and explosion hazards of the flammable substances. Explosive limit and autoignition temperature of methane fur LNG process safety were investigated. By using the literatures data, the lower and upper explosive limits of methane recommended 4.8 vol$\%$ and 16 vol$\%$, respectively. Also autoignition temperatures of methane with ignition sources recommended $540^{\circ}C$ at the electrically heated cruicible furnace (the whole surface heating) and recommended about $1000^{\circ}C$ in the local hot surface. The new equations for predicting the temperature dependence and the pressure dependence of the lower explosive limits for methane are proposed. The values calculated by the proposed equations were a good agreement with the literature data.

  • PDF

A Study on the Comparison of Explosive Lower Limit Concentration & Thermal Specific of Wheat Powder Dust & Salicylic Acid Dust (밀가루분진 및 살리실산분진의 폭발하한농도 및 열적특성 비교에 관한 연구)

  • Ko, Jae-Sun
    • Fire Science and Engineering
    • /
    • v.26 no.4
    • /
    • pp.1-9
    • /
    • 2012
  • We have examined In order to compare each other from explosion and combustion characteristics about the dusts which collects from manufacturing process of wheat flour and cosmetics manufacturing process of functional Keratin removal soap at the small and medium enterprise style. We measured explosive pressure and explosive lower limit which follows in change of concentration change at the time of talc addition uses Hartman dust explosion apparatus, also measured weight loss and endothermic quantity uses DSC and TGA. The explosion test results show that increased explosive lower limit concentration and explosive pressure decreased by the increased ratio of the talc dust. And the DSC results show that heat flux and temperature decreased by the increased ratio of the talc dust. Also increased in raising temperature causes initial smoldering temperature to move towards low temperature section and the endothermic quantity increased on a large scale. Together the TGA results show that weight loss decreased by the increased ratio of the talc dust. From this research we have assured the successive dust explosion mechanism study will play a key role as a significant safety securing guideline against the dust explosion.

A Study on Dust Explosion Characteristics of Hydroxypropyl Methyl Cellulose (Hydroxypropyl Methyl Cellulose의 분진 폭발특성에 관한 연구)

  • 임우섭;목연수
    • Journal of the Korean Society of Safety
    • /
    • v.15 no.4
    • /
    • pp.95-100
    • /
    • 2000
  • This study was performed in Hartmann type dust explosion apparatus in order to research the dust explosion characteristics of hydroxypropyl methyl cellulose(HPMC): minimum explosive limit, minimum ignition energy, limiting oxygen concentration, maximum explosion pressure, rate of pressure rise, etc. The samples of HPMC dust were distributed into 120-140 mesh, 170-230 mesh and 325 under, and the gap distance of the discharge electrode was setted up at 5mm. The experimental results were obtained as follows: (1) The minimum explosive limit for HPMC dust was founded at 180g/㎥. the minimum ignition energy at 9.8mJ and the limiting oxygen concentration at 12%. (2) The maximum explosion pressure of HPMC dust was $8.1kg/cm^2\;{\cdot}\;$abs at the concentration of $500g/m^3$ and the maximum rate of pressure rise was 203.98 bar/sec at the concentration of $480g/m^3$ for 325 under.

  • PDF

Fire Performance of Structural Lightweight Aggregate Concrete using PP fiber (PP섬유 혼입 고강도 경량골재콘크리트의 내화특성)

  • Song, Hun;Chu, Yong-Sik;Lee, Jong-Kyu
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • /
    • pp.797-800
    • /
    • 2006
  • Normally, Structural light-weight aggregate concrete(LWC) has been main used in high rise building with the object of wight loss. In spite of LWC have the advantage of light-weight, limit the use of strength restrictions by reason that explosive spalling in fire. Especially, LWC is occurred serious fire performance deterioration by explosive spalling. Thus, this study is concerned with fire performance of LWC for the purpose of using PP fibers prevent to explosive spalling. From the experimental test result, LWC is happened explosive spalling.

  • PDF

A Study on Explosive Limits of Flammable Materials - Explosive Limits of Ternary System by Means of Solution Thermodynamics and MRSM Model - (가연성물질의 폭발한계에 관한 연구 - 용액열역학 및 MRSM 모델에 의한 3성분계 폭발한계 -)

  • Ha, Dong-Myeong
    • Journal of the Korean Society of Safety
    • /
    • v.20 no.3
    • /
    • pp.91-97
    • /
    • 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.

A Study on Flash Points of a Flammable Substancea - Focused on Prediction of Flash Points in Ternary System by Solution Theory - (가연성물질의 인화점에 관한 연구 -용액론에 의한 3성분계의 인화점 예측을 중심으로-)

  • 하동명;이수경
    • Fire Science and Engineering
    • /
    • v.15 no.3
    • /
    • pp.14-20
    • /
    • 2001
  • The flash points are one of the most important fundamental properties used to determine the potential for fire and explosion hazards of flammable substances. A classification of the flash points is important for the safe handling of flammable liquids which constitute the solvent mixtures. Basic to all flash points behavior are vapor pressure and explosive limits(lower explosive limit and upper explosive limit). The flash points of flammable solvent mixtures can be calculated with the appropriate use of the fundamental laws of Raoult, Dalton, Le Chatelier and activity coefficient models. In this study, the reference values of lower flash points were compared with the calculated values by using Raoult's law and MRSM(modified response surface methodology) model. The lower flash points were in agreement with the predicted by Raoult's law and MRSM model. By means of this methodology, it is possible to evaluate reliability of experimental data of the flash points of the flammable mixtures.

  • PDF

Time dependent heat transfer of proliferation resistant plutonium

  • Lloyd, Cody;Hadimani, Ravi;Goddard, Braden
    • Nuclear Engineering and Technology
    • /
    • v.51 no.2
    • /
    • pp.510-517
    • /
    • 2019
  • Increasing proliferation resistance of plutonium by way of increased $^{238}Pu$ content is of interest to the nuclear nonproliferation and international safeguards community. Considering the high alpha decay heat of $^{238}Pu$, increasing the isotopic fraction leads to a noticeably higher amount of heat generation within the plutonium. High heat generation is especially unattractive in the scenario of weaponization. Upon weaponization of the plutonium, the plutonium may generate enough heat to elevate the temperature in the high explosives to above its self-explosion temperature, rendering the weapon useless. In addition, elevated temperatures will cause thermal expansion in the components of a nuclear explosive device that may produce thermal stresses high enough to produce failure in the materials, reducing the effectiveness of the weapon. Understanding the technical limit of $^{238}Pu$ required to reduce the possibility of weaponization is key to reducing the current limit on safeguarded plutonium (greater than 80 at. % $^{238}Pu$). The plutonium vector evaluated in this study was found by simulating public information on Lightbridge's fuel design for pressurized water reactors. This study explores the temperature profile and maximum stress within a simple (first generation design) hypothetical nuclear explosive device of four unique scenarios over time. Analyzing the transient development of both the temperature profile and maximum stress not only establishes a technical limit on the $^{238}Pu$ content, but also establishes a time limit for which each scenario would be useable.