• Journal of the Korean Institute of Gas
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• v.16 no.5
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• pp.7-13
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• 2012

An experimental study has been done to investigate the explosion characteristics of aluminum powders with different sizes and concentrations in a 20 L spherical explosion vessel. Two different sizes of aluminum powder were used : $15.1{\mu}m$ and $34.8{\mu}m$ with a volume mean diameter. The results revealed that $15.1{\mu}m$ Al powder has a Lower explosion limit (LEL) of $40g/m^3$, a maximun explosion pressure ($P_{max}$) of 9.8 bar and a maximum rate of pressure rise ($[dP/dt]_{max}$) of 1852 bar/s, in $34.8{\mu}m$ Al powder, LEL of $70g/m^3$, $P_{max}$ of 7.9 bar and $[dP/dt]_{max}$ of 322 bar/s. The LEL of Al powders tended to increase with the increase of particle size. Also, it was found that the flame velocity calculated from the powder with $15.1{\mu}m$ was about 5 times higher than that of the powder of $34.8{\mu}m$.

• Explosives and Blasting
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• v.38 no.1
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• pp.1-13
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• 2020

Gas explosion accidents are steadily being issued due to increased gas consumption in Korea and foreign countries. To analyze the effects of these gas explosions, a TNT equivalent method is used. In this study, the TNT equivalent was calculated in the event of an explosion due to the volume content in the air of CO, CH₄ and C₂H₄, the typical flammable gases emitted by coal. Also, the peak overpressure and impulse variation with the distance from explosion point were compared and analyzed by gas using the calculated equivalent value of TNT. The upper limit of the TNT equivalent for the three mixed gases is up to five times larger than the other gases mixture. In addition, the peak overpressure and impulse, which are factors of the TNT characteristic curve, are also increasing as the number of gases increases.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1998.11a
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• pp.105-108
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• 1998

Dust explosion은 combustible solid의 미세한 입자가 공기 혹은 산소중에서 폭발범위의 농도에서 부유할 때 화염 혹은 spark 등의 에너지 공급에 의해 폭발하는 현상이며 plastic 공업, 금속분말, 유기약품, 무기약품, 안료, 농수산건조물 등에서 분체취급 분야의 확대 및 취급량의 증가에 따라 분진폭발의 잠재 위험성이 급증하고 있어 화학적 성질, 농도, 입경, 폭발 압력 등의 분진특성과 함께 분진폭발의 착화온도와 상한 및 하한 농도에 대해 이론 및 실험적으로 광범위하게 연구가 진행되어져 왔다. (중략)

• Proceedings of the Korean Society of Disaster Information Conference
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• 2022.10a
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• pp.99-100
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• 2022

화학산업이 발전함에 따라 잠재적인 화학물질 폭발사고 위험 또한 증가하고 있다. 순식간에 치명적인 인명, 재산피해를 남기는 폭발에 대한 영향을 예측, 분석하기 위해 다양한 해석모델이 활용되고 있지만, 폭발의 물리적 특성상 다양한 형태의 건물이 밀집된 지역에 대해서는 해석모델 사용만으로 높은 정확도의 분석을 진행하기에는 어려움이 있다. 따라서 본 연구는 GIS 공간정보와 3D 폭발 시뮬레이션의 약결합 방식을 적용하였다. 실제 연구지역과 동일한 환경을 구현하여 시뮬레이션을 구동하였고 이에 따른 폭발 규모와 폭발에 노출된 대상별 가해지는 압력 값을 도출하였다. TNT를 기준으로 위험물 저장 및 취급시설에 대한 최저 기준인 지정수량 200kg을 적용하였음에도 최대 2,960kPa의 압력이 발생하는 것으로 확인되었다. 본 연구로 도출된 결과에 건축물의 용도와 중요도를 적용한다면 토지이용계획 및 공간활용에 반영할 수 있으며, 안전관리자로 하여금 리스크 평가, BC분석, 안전관리계획 수립 등에 활용 가능하다고 사료된다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.6
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• pp.355-364
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• 2023

The arbitrary Lagrangian-Eulerian (ALE) method has been extensively researched owing to its capability to accurately predict the propagation of blast shock waves. Although the use of the ALE method for dynamic analysis can produce unreliable results depending on the mesh size of the finite element, few studies have explored the relationship between the mesh size for the air domain and the accuracy of numerical analysis. In this study, we propose a procedure to calculate the optimal mesh size based on the mean squared error between the maximum blast pressure values obtained from numerical simulations and experiments. Furthermore, we analyze the relationship between the weight of explosive material (TNT) and the optimal mesh size of the air domain. The findings from this study can contribute to estimating the optimal mesh size in blast simulations with various explosion weights and promote the development of advanced blast numerical analysis models.

• Fire Science and Engineering
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• v.26 no.4
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• pp.1-9
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• 2012

We have examined In order to compare each other from explosion and combustion characteristics about the dusts which collects from manufacturing process of wheat flour and cosmetics manufacturing process of functional Keratin removal soap at the small and medium enterprise style. We measured explosive pressure and explosive lower limit which follows in change of concentration change at the time of talc addition uses Hartman dust explosion apparatus, also measured weight loss and endothermic quantity uses DSC and TGA. The explosion test results show that increased explosive lower limit concentration and explosive pressure decreased by the increased ratio of the talc dust. And the DSC results show that heat flux and temperature decreased by the increased ratio of the talc dust. Also increased in raising temperature causes initial smoldering temperature to move towards low temperature section and the endothermic quantity increased on a large scale. Together the TGA results show that weight loss decreased by the increased ratio of the talc dust. From this research we have assured the successive dust explosion mechanism study will play a key role as a significant safety securing guideline against the dust explosion.

• Korean Chemical Engineering Research
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• v.62 no.1
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• pp.27-35
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• 2024

Fuel gases such as methane and propane are used in explosion hazardous area of domestic plants and can form non-uniform mixtures with the influence of process conditions due to leakage. The fire-explosion risk assessment using literature data measured under uniform mixtures, damage prediction can be obtained the different results from actual explosion accidents by gas leaks. An explosion characteristics such as explosion pressure and flame velocity of non-uniform gas mixtures with concentration change similar to that of facility leak were examined. The experiments were conducted in a closed 0.82 m long stainless steel duct with observation recorded by color high speed camera and piezo pressure sensor. Also we proposed the quantification method of non-uniform mixtures from a regression analysis model on the change of concentration difference with time in explosion duct. For the non-uniform condition of this study, the area of flame surface enlarged with increasing the concentration non-uniform in the flame propagation of methane and was similar to the wrinkled flame structure existing in a turbulent flame. The time to peak pressure of methane decreased as the non-uniform increased and the explosion pressure increased with increasing the non-uniform. The ranges of K_G (Deflagration index) of methane with the concentration non-uniform were 1.30 to 1.58 [MPa·m/s] and the increase rate of K_G was 17.7% in methane with changing from uniform to non-uniform.

• 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.

• Explosives and Blasting
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• v.37 no.3
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• pp.1-12
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• 2019

The analysis methods of blast analysis models are classified into direct analysis and indirect analysis, and the latter is divided into semi-empirical and numerical analysis methods. In order to evaluate the applicability of the ELS blast analysis program, which is a program for analyzing the semi-empirical models, this study selected a simplified analytical model and examined the blast load characteristics of free-air burst explosion and surface burst explosion by using AT-Blast, RC-Blast, and Kinney and Graham's empirical equations, which are the semi-empirical analysis programs. As a result of analyzing the explosion pressure for the scaled distance and the incidence angle for the simplified analytical model, an appropriate analysis can be performed when the range of the scaled distance in the free-air burst explosion analysis was 0.3~0.461 and when the range of the scaled distance in the surface burst explosion analysis was 0.378~0.581. In terms of the incidence angle, the results analyzed within $45^{\circ}$ were considered to be appropriate.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2002.05a
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• pp.61-64
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• 2002

Dust explosion은 combustible solid의 미세한 입자가 공기 혹은 산소중에서 폭발범위의 농도에서 부유할 때 화염 혹은 Spark 등의 에너지 공급에 의해 폭발하는 현상이며 plastic 공업, 금속분말, 유기약품, 무기약품, 안료, 농수산건조물 등에서 분체취급 분야의 확대 및 취급량의 증가에 따라 분진폭발의 잠재 위험성이 급증하고 있어 화학적 성질, 농도, 입경, 폭발 압력 등의 분진특성과 함께 분진폭발의 착화온도와 상한 및 하한 농도에 대해 이론 및 실험적으로 광범위하게 연구가 진행되어져 왔다.(중략)