• 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 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.

• Journal of the Korean Society of Safety
• /
• v.13 no.2
• /
• pp.116-121
• /
• 1998

Various flammable vapors as energy source and raw material have been stored, transported in the industries, and accidental leakage of these vapors occurs occasionally. Without an appropriate protection system, flammable vapors can be ignited and serious damage results from them. To reduce the risk caused by explosion, we should know the explosion limit and explosion characteristics. In this study, the maximum explosion pressure, the maximum explosion pressure rise, the effect of temperature and mixing with other vapor were measured in a cylindrical vessel. Experimental results showed that maximum explosion pressure of flammable vapor was about 3.1~$4.2 kg/cm^2$ and it was reached 3.4 times faster than that at explosion limit. The lower explosion limit was coincided well with Le Chateilier's equation, however, upper explosion limit was not.

• 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.

• Journal of the Korean Society of Safety
• /
• v.20 no.3 s.71
• /
• pp.78-83
• /
• 2005

In this study, the evaluate characteristics of fire and explosion of MEK-PO are subjected to spontaneous ignition, flash point and explosion hazard. The minimum ignition temperature and instantaneous ignition temperature for MEK-PO were $188.5^{\circ}C\;and\;230^{\circ}C\;at\;225{\mu}L$. In addition The flash point for MEK-PO was obtained at $49^{\circ}C$. Furthermore, the maximum explosion pressure and the maximum explosion pressure rising velocity: using MCPVT (mini cup pressure vessel tester) were $10.82kgf/cm^2\;and\;33.72kgf/cm^2{\cdot}s$.

• 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.

• 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.

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

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.67 no.3
• /
• pp.474-478
• /
• 2018

The use of metals such as aluminum and titanium and the related industrial facilities have been continuously increasing to meet the requirements of the improvement of high-tech products due to the development of industry, and explosion of metal dust. Semiconductor process Metal dust is essential, but research is insufficient. The purpose of this study is to identify risk by analyzing the quantitative risk such as maximum explosion pressure and minimum explosion concentration applied international test standard in order to select the semiconductor process facilities handling dust and to predict possible risk of accidents.

• 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.