• Journal of the Korean Institute of Gas
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• v.1 no.1
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• pp.49-55
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• 1997

Destruction phenomena of structure by gas explosion is due to the explosion pressure and heat. Explosion pressure is a kind of energy converted from the gas mixture explosion. In this paper, we tried to find the relationship between explosion characteristics and combustion heat of the hydrocarbon-oxygen mixtures. Experiment were carried out with the volume of $5916cm^3$ cylindrical explosion vessel. Hydrocarbon gases which used in this study were methane, ethylene, propane, and buthane Experimental parameter was the concentration of the gas mixtures. Explosion characteristics were measured with strain type pressure transducer through the digital storage oscilloscope. From the experimental result, it was found that explosion pressure depend upon the combustion heat.

• Journal of the Korean Institute of Gas
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• v.3 no.3 s.8
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• pp.51-57
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• 1999

A study on the vented gas explosion characteristics were carried out with the liquified petroleum gas(LPG) which is used in domestics and industries fuel. To evaluate a damage by gas explosion and to predict a explosion hazards, a series of experiment have been performed in the regular hexahedron vessel of 270${\iota}$. A side of the vessel was made to setting a polyester diaphragm which was ruptured by explosion to simulate an accidental explosion which ruptured the window by explosion. Experimental parameters were LPG concentration, ignition position, venting area, a strength of diaphragm which was ruptured and distances from venting, Experimental results showed that vented gas explosion pressure was more affected by the diaphragm strength than the gas concentration, and the vented gas explosion pressure and blast wave pressure was increased with decreasing the venting area and increasing the strength of diaphragm. In this research we can find that a damage by vented explosion at the outside can be larger than the inside by blast wave pressure near the venting.

• 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.8 no.4
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• pp.107-113
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• 1993

Small rectangular explosion chamber of its size 25cmX25cmX32cm with a circular bursting diaphram at the top was used to study the mechanism of gas explosion to fire transition phenomena, the process of ignition of solid combustibles during a gas explosion. To visulize the explosion to fire transition phenomena, transparent acryl window and high speed camera system were used. The test piece of solid combustible in this experiments was a 5cm$\times$5cm square sheet of newspaper which was placed in the explosion chamber filled with a LPG-air mixture. The mixture was ignited by an electric spark at the center of the chamber. Explosion to fire transition phenomena and the behavior of out flow and in flow of gas through the opening yielded by bursting the diaphram was visualized with shlieren system and without shlieren system. Diameter of a bursting dlaphram at the top of the explosion chamber was varied 5cm, 10cm, and 15cm, and the position of test piece were varied with 6 point. Explosion pressure was measured with strain type pressure transducer, and the weight difference of the test piece before and after each experimental run was measured. By comparing the weight difference of solid combustibles before and after the experiment and the behavior of out flow and inflow of gas after explosion, it was found that the possibility of ignition was depends on the LPG-air mixture concentration and the exposure period of test piece to the burnt gas. Test result of this experiments it was found that the main factor of this phenomena are that heat transfer to the test piece, and the pyrolysis reaction of test piece. Based on the results, the mechanism of the explosion to fire transition phenomena were inferred ; gas explosion- heat transfer to solid combustibiles ; pyrolysis reaction of solid combutibles : air inflow ; mixing of the pyroly gas with air ignition.

• Journal of the Korean Institute of Gas
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• v.11 no.1 s.34
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• pp.13-17
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• 2007

It is very insecure to treat a butane can for cooking out of door. The human injury from the accidents of butane cans has been getting increased 1.5 times yearly since 2003. In this context, the Institute of Gas Technology Training in Korea Gas Safety Corporation carries out explosion experiment to make trainees to take all possible measures to ensure safe management of gas in the field by fully recognizing the hazards of gas explosion accidents. This study intends to examine the influence of such explosion experiments on the trainees witnessing nearby. The GEN exposed to the active students participating in the experiment away from 25 meters from the explosion site was 57.94 dB and the GEN to the passive students not participating away from 50 meters was 51.92 dB. According to Weber-Fechner's law for the lower value than 65 dB which is the environmental standard, it is safe from the place 15 meter far from the explosion place. The environmental standard of offices is 50 dB, and it is lower than the environmental standard if the office is 65 meter far from the explosion place.

• Journal of the Korean Society of Safety
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• v.21 no.3 s.75
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• pp.38-44
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• 2006

The majority of both small and large-scale experiments on gas explosion have been carried out in the explosion instruments with cylindrical tubes of a high length/diameter ratio and vessels of a high height/length ratio, focusing on investigating the interaction between propagating flame and obstacles inside the tubes or vessels. The results revealed that there is a strong interaction between the propagating flame and turbulence formed after the flame passes the obstacle. However this paper focuses on analyzing the pressure impact or profile outside the vent in vented gas explosion in a partially confined chamber by performing gas explosion experiments in a reduced-scale experimental assembly properly constructed. This study has considered eight different cases in gas explosion based on variation of three kinds of parameters such as height of vessel, shape of the vent and vent size, and reveals that the large vessel with big size circle vent is more danger to the target than others because the overpressure is spread out faraway horizontally and vertically.

• Explosives and Blasting
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• v.33 no.3
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• pp.1-13
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• 2015

Accidents related to gas explosion are frequently happened in foreign countries and in Korea. For the evaluation and the analysis of gas explosions, TNT equivalent methods are used. In this study, the influence of the selection of chemical equation in TNT explosion and the selection of enthalpy of the products on the explosion energy, detonation pressure, velocity of detonation, and temperature was calculated. Depending on the chemical equations, the maximum detonation pressure can be 2 times higher than the minimum. As an example for applying TNT equivalent method, an explosion of methane gas in a confined volume was assumed. With the TNT equivalent, it was possible to predict the variation of peak overpressure and impulse with the distance from the explosion location.

• Journal of the Korean Institute of Gas
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• v.20 no.3
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• pp.59-65
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• 2016

It is imperative to use suitable explosion proof equipments to prevent explosion in different gas facilities. There is no technical standard for the classification of hazardous areas though standard of explosion proof is regulated. In this study, we have adopted Industrial Standard KS to develop the methodology for the prediction of the explosion risk in the natural gas facility with low pressure using the important factors including hole size, hypothetical volume, validation of ventilation effectiveness. The applicability of the developed methodology was evaluated by the comparison with the data obtained from experiments of natural gas explosion.

• Journal of the Korean Society of Safety
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• v.7 no.3
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• pp.35-42
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• 1992

Ignition energy effects of concentration of mixed gas In closed cylindrical vessel(1, 832㎤) are studied. The ignition energy ranged from 25 Joule to 110 Joule, and hidrogen and methane gases were used for flammable gas at stoichiometric condition with oxygen gas and nitrogen gas (N2) was for inert gas, which concentration was maximum 60% . The explosion pressure, temperature, concentration of product gases were calculated. It is found that - The explosion pressure and explosion velocity increase with ignition energy. - The gradience of explosion velocity with ignition energy is steeper than explosion pressure. - The results of calculation are similiar with results of experiment. - NOx is not serious product gas for methane and hydrogen gas, but CO is serious at certain concentration for methane in asphyxiation.

• Journal of the Korea Safety Management & Science
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• v.25 no.1
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• pp.51-58
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• 2023

Determination of explosion reference pressure is important in designing and testing flameproof enclosures (Ex d). Although relative humidity affects to explosion pressure, its effect is not well investigated for the gas group IIB, IIA, and I. This study tested explosion pressure for Ethylene (8 vol.%), Propane (4.6 vol.%), and Methane (9.8 vol.%), which are the representative gas of the gas group IIB, IIA, and I, at ambient temperature and atmospheric pressure (1 atm) under different relative humidity (0% ~ 80%). Ethylene- and Propane-air mixed gases generally tended to decrease as the relative humidity increased; however, explosion pressure was largely dropped at 20% of relative humidity compared to 0% and 10% of relative humidity. On the other hand, Methane-air mixture gas showed similar pressures at 0% and 10% of relative humidity; but no explosion occurred at more than 20%. The results of this study can be used in setting a testing protocol of explosion reference pressure for designing and testing a flameproof enclosure.