• Journal of the Korean Institute of Gas
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• v.24 no.3
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• pp.20-26
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• 2020

In this study, experimental study was conducted to examine the influence of explosion pressure and flame propagation velocity of methane-air mixtures due to the obstacles placed in the explosion space. We used the quantified parameter named barrier ratio in order to generalize the effect of explosion pressure and flame propagation velocity in the closed explosion space with obstacles. From experimental observations, the explosion pressure and flame propagation velocity regardless of the number of obstacles increased with barrier ratio. In the same methane concentration of 10% methane, the flame propagation velocity without obstacle (barrier ratio = 0) was 3.46 m/s but 24.24 m/s (increase about 7 times) with 3 obstacle and barrier ratio of 0.98. In the same barrier ratio, explosion pressure and flame propagation velocity increased sharply with increasing of the number of obstacles.

• Journal of the Korean Institute of Gas
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• v.9 no.1 s.26
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• pp.38-43
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• 2005

To examine the characteristics of the explosion of city gas, the concentration of oxygen was changed with the change of initial pressure. From the result of the experiment, as the concentration of oxygen was low, the explosion limit became narrow and the minimum concentration of oxygen for the explosion was $12\%$. Furthermore, As the increase of the initial pressure, explosion ranges were a little increased. And as the change of the initial pressure, the maximum explosion pressure were $6.3 kgf/cm^2{\cdot}g,\;12.7 kgf/cm^2{\cdot}g$ and the maximum pressure rising velocity were $245.63 kgf/cm^2/s,\;427.88 kgf/cm^2/s$.

• Fire Science and Engineering
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• v.17 no.4
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• pp.111-116
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• 2003

LPG explosion characteristics in non-uniform concentration was investigated with a 270 liter explosion vessel of which the scale is 100 cm${\times}$60 cm${\times}$45 cm. Vented explosion and closed explosion system were used. Experimental parameter were position of ignition source, nozzle diameter and flow rate of gas. Non uniform concentration was controlled by the nozzle diameter and flow rate. Explosion pressure were measured with strain type pressure sensor and the flame behavior was pictured with the video camera. Based on this experimental result, it was found that the flow rate of gas and the duration of gas injection are important factor for mixing the gas in the vessel. And as the increase the non-uniformity of gas concentration, explosion pressure and pressure rise rate Is decrease but the flame resident time in the vessel is increase. Therefore gas explosion to fire transition possibility will increase in non-uniform concentration gas explosion.

• Journal of the Korean Society of Safety
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• v.14 no.3
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• pp.40-47
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• 1999

A numerical study on gaseous explosion was carried out to predict the transient pressure behavior with the partial rupture in confined vessels. Equations, assumptions and solutions for central ignition of premixed gases in closed spherical vessels are proposed with various equivalence ratios of gas fuel, as $CH_4$ and $C_3H_8$, vent areas and vent opening pressures. Given vent opening pressure in a vessel, the magnitude of second peak pressure results from the vent areas and burning velocity, varied by equivalence ratio of gas fuel. In a living room of an apartment, the higher second peak pressure than the vent pressure is not appeared due to its large window areas. As vent opening pressure is higher, the larger damage by gaseous explosion is expected and the larger vent area is necessary for relieving the damage. In the same concentration, the gaseous explosion by propane rather than methane shows the larger damage due to its higher adiabatic flame temperature and equivalence ratio.

• Journal of the Korean Institute of Gas
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• v.8 no.4 s.25
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• pp.50-54
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• 2004

To examine the danger of explosion caused by decomposition explosion of Methyl Ethyl Ketone Peroxide, the mini cup pressure vessel tester (MCPVT) was used in the experiment. The maximum explosion pressure increased as the amount of $98\%H_2SO_4$ added to MEKPO increased from $0\%$ to $1\%,\;3\%$, and $5\%$, and the maximum pressure rising velocity increased as well. In addition, the temperature under the pressure at which decomposition starts decreased from $168.16^{\circ}C$ to $126.76^{\circ}C,\;91.21^{\circ}C$, and $81.25^{\circ}C$ as the amount of $H_2SO_4$ added increased.

• Journal of the Korean Society of Safety
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• v.33 no.2
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• pp.39-44
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• 2018

Dust explosions are occurring in a variety of industries. A dust explosion caused by a specific energy generates huge amount of energy in the ignition and releases decomposition gas. Damages can be increased since this released decomposition gas can cause second and subsequent explosions. In this study, the goal was to obtain practical information on what could affect the explosion by comparing the characteristics of two kinds of dusts with completely different chemical properties. Three kinds of dusts were measured and evaluated for explosion pressure, dust explosion index, explosion limit and minimum ignition energy. It is possible to grasp the characteristics of each dust and use it as useful accident prevention data in the production of raw material powder.

• Journal of the Korean Society of Safety
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• v.16 no.4
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• pp.109-114
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• 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.

• Journal of the Korean Institute of Gas
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• v.10 no.3 s.32
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• pp.60-64
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• 2006

Explosion range and explosion characteristics of by product gas from carbon black manufacturing process were studied. About 75% of the by product gas were composed with water vapour and nitrogen. And the combustible component in the gas were hydrogen, methane, acetylene and carbon mono-oxide. Because of the combustible components in the by product gas there are explosion hazards in the gas handling process. Explosion range of the gas by experiment was from 17.1% to 70.7% and the value has considerable difference with the calculated value from Lechatelier law. Explosion pressure of the gas was $5.4kg/cm^2$ and the average explosion pressure rise rate was $39.2kg/cm^2/s$. Based on the experimental result we can expect that a explosion or fire accident during the handling the gas can make a severe loss, therefore there should be a explosion prevention or protection measures in the gas handling process.

• Journal of the Korean Society of Safety
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• v.19 no.4 s.68
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• pp.150-154
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• 2004

Gas explosion characteristics of hydrogen and liquefied petroleum gas(LPG) were measured in 6L cylindrical vessel, and experiment for explosion to fire transition phenomena of the gases were carried out using the 270L vessel. Explosion characteristics were measured using the stain type pressure transducer and explosion to fire transition phenomena was analyzed with the hish-speed camera. Base on the experiment, it was found that explosion pressure was most high slightly above the stoichiometric concentration, and explosion pressure rise rate and flame propagation velocity were proportional to the combustion velocity. And we find that those kind of explosion characteristics affect the explosion-to-fire transition, in addition, explosion flame temperature, flame residence time, are important parameters in explosion-to-fire transition.

• Journal of the Korean Institute of Gas
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• v.16 no.6
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• pp.1-6
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• 2012

Using the Siwek 20 L spherical explosion vessel, the explosion properties have been examined to understand the influence of magnesium content in Mg-Al alloy dusts with different concentration. For this purpose, the Mg-Al alloy dusts (volume mean diameter : $151{\sim}160{\mu}m$) with magnesium content ratio were used. As the results, the increase of Mg content in Mg-Al alloy causes an decreased minimum explosion concentration and an increased maximum explosion pressure. Also the maximum explosion pressure and maximum rate of pressure rise in Mg-Al alloy dusts mainly depended on the dust concentrations. However, for the explosion index (Kst) of Mg-Al (40:60 wt%), Mg-Al (50:50 wt%) and Mg-Al (60:40 wt%), it was founded to increase the Kst with increasing of magnesium content ratio.