• Journal of the Korean Society of Safety
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• v.28 no.2
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• pp.49-54
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• 2013

The autoignition temperature(AIT) is 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-Decane and Acetic acid system by using ASTM E659 apparatus. The AITs of n-Decane and Acetic acid which constituted binary system were $212^{\circ}C$ and $512^{\circ}C$, respectively. The experimental AITs of n-Decane and Acetic 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-Decane and Acetic acid system was shown the minimum autoignition temperature behavior(MAITB).

• Fire Science and Engineering
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• v.20 no.1 s.61
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• pp.1-5
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• 2006

The spontaneous ignition of a flammable matter is a crucial factor for the prevention of a fire. The minimum ignition temperatures of Gasoline and Cenox in $1000{\mu}l$ of a sample were determined to be $340.5^{\circ}C\;and\;368.5^{\circ}C$ respectively. In addition when the time taken for ignition was 1.0 sec, the instantaneous ignition temperatures were $416^{\circ}C\;and\;427^{\circ}C$ respectively. Moreover, the changes in the minimum ignition temperature were small when less than 60 v/v% of Cenox was added, but the changes were great when 80 v/v% or more was added. Therefore, it is hypothesized that, when used as a fuel in the Gasoline engine, the ratio of the mixture of Cenox and Gasoline will be a very important factor.

• Fire Science and Engineering
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• v.13 no.1
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• pp.37-47
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• 1999

The spreading fire of very small floating particles after they are ignited is fast and t therefore dangerous. The research on this area has been limited to experiments and global simulations which treat them as dusts or gaseous fuel with certain concentration well m mixed with air. This research attempted micro-scale analysis of ignition of those particles modeling them as liquid droplets. For the beginning, the in-line array of fuel droplets is modeled by two-dimensional, unsteady conservation equations for mass, momentum, energy and species transport in the gas phase and an unsteady energy equation in the liquid phase. They are solved numerically in a generalized non-orthogonal coordinate. The single step chemical reaction with reaction rate controlled by Arrhenius’ law is assumed to a assess chemical reaction numerically. The calculated results show the variation of temperature and the concentration profile with time during evaporation and ignition process. Surrounding oxygen starts to mix with evaporating fuel vapor from the droplet. When the ignition condition is met, the exothermic reactions of the premixed gas initiate a and burn intensely. The maximum temperature position gradually approaches the droplet surface and maximum temperature increases rapidly following the ignition. The fuel and oxygen concentration distributions have minimum points near the peak temperature position. Therefore the moment of ignition seems to have a premixed-flame aspect. After this very short transient period minimum points are observed in the oxygen and fuel d distributions and the diffusion flame is established. The distance between droplets is an important parameter. Starting from far-away apart, when the distance between droplets decreases, the ignition-delay time decreases meaning faster ignition. When they are close and after the ignition, the maximum temperature moves away from the center line of the in-line array. It means that the oxygen at the center line is consumed rapidly and further supply is blocked by the flame. The study helped the understanding of the ignition of d droplet array and opened the possibility of further research.

• Journal of the korean Society of Automotive Engineers
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• v.10 no.5
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• pp.54-60
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• 1988

This study is a theoretical analysis and experimental effect of oxygen concentration, exhaust velocity and trap inlet temperature on particulate ignition temperature with installation of ceramic filter trap in diesel engine. So the following results are obtained. 1, Based on the fundamental experiments of the regeneration process, the analytical model was developed and the results from the analytical model agreed with the experiments, then the validity of the model was proved. 2, The ignition temperature for accumulated particulate was proportional to the exhaust velocity and it was known that the optimum exhaust velocity was about 15m/sec. 3, The ignition temperature for accumulated particulate was inversely proportional to the oxygen concentration and the trap inlet temperature, and a minimum oxygen concentration of 5% was required to sustain regeneration. 4, This experimental filter trap(EX-66) is found about 30% of smoke reduction efficiency in comparison with existing muffler.

• Fire Science and Engineering
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• v.30 no.1
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• pp.24-30
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• 2016

Autoignition characteristic is an important factor of all combustible substances, and a critical determinant in assessing the effectiveness of fire hazard prevention. This study investigated the autoignition characteristic of mixtures of Ethylene Glycol and water using an ASTM D2155 type ignition temperature measuring apparatus. It was possible to get the minimum temperature as $434^{\circ}C$ from 100% Ethylene Glycol within range of $75{\sim}160{\mu}l$. A volume of $100{\sim}125{\mu}l$ of a mixed sample of Ethylene Glycol and water (80 : 20) was ignited at the same temperature ($434^{\circ}C$). Also it was possible to get the auto ignition temperature as $437^{\circ}C$ from a mixed sample of Ethylene Glycol and water (60 : 40) within range of $120{\sim}160{\mu}l$. The instantaneous ignition temperatures determined for $125{\mu}l$ of each of the three samples were $579^{\circ}C$, $595^{\circ}C$ and $611^{\circ}C$, respectively. Both auto ignition temperatures and instantaneous ignition temperatures were increased through the addition of water to the samples.

• Journal of the Korean Society of Safety
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• v.5 no.2
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• pp.17-23
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• 1990

This study was performed by experiments with ASTM's apparatus for determination of autoignition temperature to obtain autoignition characteristics of 1-Heptene, 2-Heptene and 3-Heptene, respectively. As results, minimum autoignition temperatures (MAIT) of 1-Heptene, 2-Heptene and 3-Heptene were 246$^{\circ}C$, 248$^{\circ}C$ and 254$^{\circ}C$, respectively and each dropping volume of these temperatures was 0.25$m\ell$, 0.20$m\ell$ and 0.20$m\ell$. Instantaneous ignition temperatures measured at each dropping volume of Heptene were 371$^{\circ}C$, 357$^{\circ}C$ and 342$^{\circ}C$, respectively. Relation ignition delay time with ignition temperature at minimum autoignition temperature agreed well with Semenov's equation, and the values of apparent activation energy from this equation were 47Kca1/mo1 for 1-Heptene, 35Kca1/mo1 for 2-Heptene and 29Kca1/mo1 for 3-Heptene. It was found that the values of apparent activation energy decreased as the position of double bond changed from end to center in C-C chain.

• Journal of the Korean Society of Safety
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• v.19 no.2
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• pp.54-60
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• 2004

Flammable substances are frequently used chemical industry processes. An accurate knowledge of the ALTs(Autoignition Temperatures) is important in developing appropriate prevention and control measures in industrial fire protection. The AITs describe the minimum temperature to which a substance must be heated, without the application of a flame or spark, which will cause that substance to ignite. The AITs are dependent upon many factors, namely initial temperature, pressure, volume, fuel/air stoichiometry, catalyst material, concentration of vapor, ignition delay. This study measured relationship between the AITs and the ignition delay times by using ASTM E659-78 apparatus for methanol and ethanol. The A.A.P.E.(Average Absolute Percent Error) and the A.A.D.(Average Absolute Deviation) of the experimental and the calculated delay times by the AITs for methanol were 14.59 and 1.76 respectively. Also the A.A.P.E. and the A.A.D. of the experimental and the calculated delay times by the ATIs for ethanol were 8.33 and 0.88.

• Journal of the Korean Society of Safety
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• v.25 no.4
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• pp.13-18
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• 2010

To investigate electrostatic ignition hazards of commercial gasoline used in the gas station, experiments were conducted dealing with the minimum ignition energy(MIE) of several kinds of gasoline under the various temperature. The conductivity of gasoline that was required for an accurate risk assessment as well as the MIE were also examined. The solvent ignitability apparatus which can heat up the inside of the vessels up to $210^{\circ}C$ was used in this study. Four kinds of premium gasoline and four kinds of regular gasoline, differing with respect to the companies, were used as test specimens. The following results were obtained: (1) all gasoline specimens were so sensitive that even an electrostatic discharge with a very low energy, such as about 0.5mJ, could ignite them. The ignitability of premium gasoline was constant irrespective of the companies. On the other hand, the ignitability of regular gasoline was variable depending on the company. (2) The MIE of all specimens depended markedly on the temperature; in other words, an increase in temperature decreases the ignition energy value. (3) The conductivity values of all specimens were low. Those must be taken into consideration in electrostatic risk assessment.

• Korean Chemical Engineering Research
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• v.57 no.6
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• pp.790-803
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• 2019

The dioctyl terephthalic acid (DOTP) process produces plastic plasticizers by esterification of terephthalic acid with powder in the form of octanol. In this study, the dust explosion characteristics of terephthalic acid directly injected into the manhole in the form of powder in the presence of flammable solvent or vapor in the reactor of this process were investigated. Dust particle size and particle size distribution dust characteristics were investigated, and pyrolysis characteristics of dust were investigated to estimate fire and explosion characteristics and ignition temperature. Also, the minimum ignition energy experiment was performed to evaluate the explosion sensitivity. As a result, the average particle size of terephthalic acid powder was $143.433{\mu}m$. From the thermal analysis carried out under these particle size and particle size distribution conditions, the ignition temperature of the dust was about $253^{\circ}C$. The lower explosive limit (LEL) of the terephthalic acid was determined to be $50g/m^3$. The minimum ignition energy (MIE) for explosion sensitivity is (10 < MIE < 300) mJ, and the estimated minimum ignition energy (Es) based on the ignition probability is 210 mJ. The maximum explosion pressure ($P_{max}$) and the maximum explosion pressure rise rate $({\frac{dP}{dt}})_{max}$ of terephthalic acid dust were 7.1 bar and 511 bar/s, respectively. The dust explosion index (Kst) was 139 mbar/s, corresponding to the dust explosion grade St 1.

• Fire Science and Engineering
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• v.18 no.2
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• pp.27-33
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• 2004

An accurate knowledge of the AIT(Autoignition temperatures) of chemicals is important in developing appropriate prevention and control measures in industrial fire protection. The AITs describe the minimum temperature to which a substance must be heated, without the application of a flame or spark, which will cause that substance to ignite. The measurement AITs are dependent upon many factors. namely initial temperature. pressure, volume, fuel/air stoichiometry. catalyst material, concentration of vapor, ignition delay time. This study measured the AITs of acids from ignition delay time by using ASTM E659-78 apparatus which was produced in the year 1994. The experiment AITs were a good agreement with the calculated AITs by the proposed equations with a few A.A.P.E.(average absolute percent error) and A.A.D.(average absolute deviation).