• Journal of the Korean Society of Safety
• /
• v.7 no.3
• /
• pp.66-72
• /
• 1992

An experimental study was carried out to analyse the explosion characteristics of flammable gas-air mixtures. Used flammable gases were hydrogen, methane, acethylene, ethylene and pro-pane, explosion Pressure, explosoin pressure rising rate, and flame propagation velocity were measured experimentaly. The maximum explosion pressure and rising rate of flammmalbe gas air mixtures were appeared at the range of slightly higher concentration than the stoichiometric concentration. Initial pressure before explosion was controlled from 0.6 to 2.0kg/cm absolutly. Explosion pressure was increased with increment of the initial pressure, and the relationship between initial pressure and explosion pressure was Pe = KPi. The effect of vessel size on explosion characteristics was also analysed In this experiment. Explosion pressure was increased with in-creasing the vessel size, otherwise explosion pressure rising rate was decreased. When we locate a dummy material in vessel explosion pressure was decreased with increasing the dummy volume but exlosion pressure rising rate was increased.

• Transactions of the Korean hydrogen and new energy society
• /
• v.15 no.3
• /
• pp.228-234
• /
• 2004

It was discussed about explosion danger of hydrogen gas experimentally that could be happen during the handling and using. Hydrogen concentration was varied from 10 to 60 vol% for get the explosion characteristics of hydrogen and 5 kinds of cylindrical vessel were used to find the explosion characteristics of hydrogen according to the vessel volume. Initial pressure of hydrogen-air mixture was varied from 0.6 to 2 kg/cm2. Based on the experiment, explosion pressure was most high near the 30vol% of hydrogen and explosion pressure was increased slightly according to the increase of vessel volume but explosion pressure rise rate was decreased. Explosion pressure was increased linearly proportional to the initial pressure of gas mixture.

• Journal of the Korean Society of Safety
• /
• v.5 no.1
• /
• pp.41-48
• /
• 1990

In this study the explosion characteristics of terephtalic acid dust(PTA) was investigated with the Hartmann type apparatus. The minimum ignition energy, minimum explosible concentration, flame propagation velocity, explosion pressure, explosion pressure rise rate and the effect of inert dust(talcum) on explosion characteristics were measured. Flame velocity was 50m/s at 700g/m$^3$ concentration, and the explosion pressure and explosion pressure rise rate were most likely with that of gas explosion. It was found that an inert dust acts as a heat sinker and it disturbs the combustion of flammable dust, as a result, explosion pressure and explosion pressure rise rate were decreased and minimum explosion concentration was increased with increasing the fraction of talcum dust in PTA.

• Journal of the Korean Society of Safety
• /
• v.8 no.4
• /
• pp.114-119
• /
• 1993

The explosion characteristics of nonhomogeneous LPG-Air mixtures was measured in a cylindrical vessel and a pipe. The maximum explosion pressure, the maximum rate of explosion pressure rise, and the flame propagation velocity were measured and compared with that of homogeneous explosion by changing the effective factors on the explosion of nonhomogeneous mixtures such as pressure difference, effusion time and delay time. Explosion was occured even in the lower concentration than the lean flammability limit of mixture. The maximum explosion pressure was increased with increase of LPG concentration, however, the maximum explosion pressure rise was not in the nonhomogeneous explosion. An d the flame propagation velocity was decreased with nonhomogeneity, however, the maximum explosion pressure was always above 0.7kg/$\textrm{cm}^2$.

• Journal of the Korean Institute of Gas
• /
• v.16 no.1
• /
• pp.8-14
• /
• 2012

Hydrogen is considered to be the most important future energy carrier in many applications reducing significantly greenhouse gas emissions, but the explosion safety issues associated with hydrogen applications need to be investigated and fully understood to be applicable as the carrier. The risk associated with a explosion depends on an understanding of the impacts of the explosion, particularly the pressure-time history during the explosion. This work provides the effects of explosion parameters, such as specific heat ratio of burned and unburned gas, equilibrium maximum explosion pressure, and burning velocity, on the pressure-time history with flame growth model. The pressure-time history is dominantly depending on the burning velocity and equilibrium maximum explosion pressure of hydrogen-air mixture. The pressure rise rate increase with the burning velocity and equilibrium maximum explosion pressure. The specific heat ratio of unburned gas has more effect on the final explosion pressure increase rate than initial explosion pressure increase rate. However, the specific heat ratio of burned gas has more influence on initial explosion pressure increase rate. The flame speeds are obtained by fitting the experimental data sets. The flame speeds for hydrogen in air based on our experimental data is very low, making a transition from deflagration to detonation in a confined space unlikely under these conditions.

• Fire Science and Engineering
• /
• v.29 no.6
• /
• pp.20-25
• /
• 2015

In order to examine the explosion risk of 2-ethylhexanoic acid, we experimentally studied the explosion limit, explosion pressure, and rate of increase of the explosion pressure at different oxygen concentrations. The lower explosion limit was 3.2% at a temperature of $100^{\circ}C$, and the oxygen concentration was 40 to 70%. The upper explosion limit was 4.5% and the lower explosion limit was 4.0% at an oxygen concentration of 21%.The maximum explosion pressure of 2-ethylhexanoic acid was 1.4161 MPa at an oxygen concentration of 70%, and the rate of increase of the explosion pressure was 62.692 MPa/s at this concentration.

• Journal of the Korean Society of Safety
• /
• v.30 no.4
• /
• pp.56-63
• /
• 2015

Gas explosion accidents could cause a catastrophe. we need specialized and systematic accident investigation techniques to shed light on the cause and prevent similar accidents. In this study, we had performed LNG explosion simulation using AUTODYN which is the commercial explosion program and predicted the damage characteristics of the structures by LNG explosive power. In the first step, we could get LNG's physical and chemical explosion properties by calculation using TNT equivalency method. And then, by applying TNT equivalency value about the explosion limit concentration of LNG on the 2D-AUTODYN simulation, we could get the explosion pressure wave profiles (explosion pressure, explosion velocity, etc.). In the last step, we performed LNG explosion simulation by applying to the explosion pressure wave profiles as the input data on the 3D-AUTODYN simulation. As a result, we had performed analyzing of the explosion characteristics of LNG in accordance with concentration through the 3D-AUTODYN simulation in terms of the explosion pressure behavior and structure's destruction and damage behavior.

• Journal of the Korean Society of Safety
• /
• v.20 no.3 s.71
• /
• pp.71-77
• /
• 2005

This study aims to find the safe vent area to prevent a destruction of building by gas explosion in a building. Explosion vessel which used in this experiment is 1/5 scale down model of simple livingroom and its dimension is 100cm in length 60cm in width and 45cm in height. Liquified petroleum gas(LPG) was injected to the vessel to the concentration of 4.5vol%, and injection rate were varied in 1L/min or 4L/min. Gas mixture was ignited by the 10kV electric spark. For analysis the characteristics of vented explosion pressure according to the vent size and vent shape, its size and shape were varied. From the experiment, it was found that explosion pressure in the vented explosion :in affected by the gas injection rate, vent area and vent shape. And the vent area to volume ratio(S/V) to prevent the building destruction by explosion pressure, it is recommended that the design of vent area happened by the explosion should be above 1/500cm in S/V. And if the vent area has complicate structure in same area, vented explosion pressure will be higher than a single vent, and possibility of building destruction will increase. Therefore to effectively vent the explosion pressure for protect a building and residents from the gas explosion hazards, the same vent area should have a singular and constant shape in the cross-sectional area of the vessel.

• Journal of the Korean Society of Safety
• /
• v.20 no.4 s.72
• /
• pp.34-39
• /
• 2005

To evaluate characteristics of explosion hazard of Methyl Ethyl Ketone Peroxide, MCPVT was used for this study. In result maximum explosion pressure and maximum explosion pressure rising velocity of MEK-PO were $12.1kgf/cm^2\;and\;106.81kgf/cm^2/s$. As a result or adding metal powder to estimate hazard of explosion, the maximum explosion pressure and maximum explosion pressure rising velocity according to adding Fe powder in MEK-PO increased. In opposite, those decreased resulting in adding Ca powder in MEK-PO.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 1997.11a
• /
• pp.275-281
• /
• 1997

The destruction by accident is affected by the blast of explosion. However, there are few of research on the external effect of vented gas explosions. Therefore it is necessary to study the effect of vented explosion. This study aims to find the characteristics of gas explosion, and the effect of vented gas explosion. Using an explosion chamber, we obtained a LPG explosion characteristics according to the vent size and concentration. The result of experiment showed that the explosion pressure effect to external space was much stronger than inner space during the course of a gas explosion. And the external pressure become higher in explosion pressure as the vent diameter become smaller.