• Journal of Convergence for Information Technology
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• v.7 no.5
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• pp.103-109
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• 2017

A pressure vessel is a cylindrical container that accommodates a pressurized fluid. In real life, there are propane canisters and butane canisters. According to data from the Korea Gas Safety Corporation, The number of domestic gas accidents is average 33 cases of domestic gas accidents occurred per year and 20.8 for mobile butane gases. The purpose of this study was to investigate a method to prevent this kind of explosion. Common studies include forced drain through safe holes, forced separation of butane canisters, and manufacturing of high-strength steel. This paper uses a concept that reduces stress inside the cylinder using prestressed method that precede compression. In other words, install a long liner in both ends of the pressure vessel. I want to develop a safety device that acts like a gas intermediate valve.

• Journal of the Korean Institute of Gas
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• v.17 no.4
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• pp.33-38
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• 2013

A study was carried out on the effect of particle size (mean diameter) on magnesium dust explosion. Experimental investigations were conducted in a 20-L explosion sphere, using 10 kJ chemical ignitors. Explosion tests were performed with three different dusts having mean diameter (38, 142, $567{\mu}m$) and the dust concentrations were up to $2250g/m^3$. The lower explosion limits(LEL) of magnesium dusts were about $30g/m^3$ at $38{\mu}m$ and $40g/m^3$ at $142{\mu}m$. LEL tended to increase with particle size and this means that the explosion probability of magnesium dust decreased with increase of particle size. The maximum explosion presssure ($P_m$) and $K_{st}$ (Explosion index) decreased with the increase of particle size. For magnesium powder of $567{\mu}m$, however, the explosive properties were not observed in the 5 kJ ignition energy.

• Journal of the Korean Institute of Gas
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• v.17 no.5
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• pp.81-86
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• 2013

Accidents of dust explosion has been occurred in various industries as a plastics, pharmaceuticals, timber, grain storage, solid fuels and chemicals. In this study, the silo dust, hammer mill dust and Nyusong dust in the manufacturing process of the particle board to utilize west wood, which were selected for this experiment and were evaluated the characteristics of dust explosion. The explosion characteristics such as a maximum explosion pressure, explosion index, lower explosive limit, and minimum ignition energy in suspended dust of the wood by Siwek 20 L apparatus were measured and evaluated for the experiment. The results of this study can be used the process safety measures to prevent accidents of fire and explosion in the suspended dust of wood.

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

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1513-1514
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• 2015

전력설비가 열화, 서지에 의해 절연이 파괴되었을 경우 밀폐기기 경우 폭발, 화재를 일으킴으로써 일반인에게 피해를 입히거나 인근 설비로 파급이 확대될 가능성이 있다. 최근 전력설비는 대용량화 추세인 반면 콤팩트 사이즈를 요구하고 있어 절연문제로 인한 폭발 가능성은 더욱 커지고 있다. 이러한 전력설비의 폭발을 방지하고 피해확대를 줄이기 위해 방압변, 순간압력상승 방지장치 등이 설치되고 있으나, 예방에는 한계가 있다. 이에 최근, 국외를 중심으로 전력기기 특히, 지상설치기기의 안전성 확보를 위해 고속투입 접지스위치(Arc Eliminator)를 개발하여 설치 의무화를 고려하고 있다.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2003.04a
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• pp.34-34
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• 2003

전기설()폭발(Electric Wire Explosion)법은 고밀도 전류를 금속와이어에 인가시키면 저항 발열에 의해서 금속와이어가 빠르게 가열되고, 수$\mu$sec 이내에 초기체적에 비해 2~3배나 팽창한 후 폭발하는 현상을 이용하여 나노분말을 제조하는 방법으로써, 다른 제조방법에 비해 값싼 비용으로 1~50$\mu$sec의 짧은 시간동안 극히 높은 온도($10^4~10^6K$)에 도달하기 때문에, 와이어 전체가 동시에 기화하여 원재료의 조성을 갖는 분말의 합성이 가능하며, 공급되는 에너지와 시간, 챔버의 용적과 압력을 제어함으로써 평균 분말 크기를 조절할 수 있다는 잇점이 있다. 또한, 금속 와이어 주위의 분위기를 조절함으로써 금속나노분말뿐만 아리나 산화물$\cdot$질화물$\cdot$탄화물 분말, 합금 분말, 화학적 화합물이나 복합재료 나노분말들을 만들 수 있어서 여러 산업분야에 대한 응용이 크게 기대되고 있다. 본 연구에서는 전기선()폭발 챔버(Fig. 1) 와 최대 20kV까지 제어 가능한 고출력 펄스 전원장치를 자체 제작하고, 이를 이용하여 은(Ag)나노분말 합성에 대한 실험을 행하였다. 이렇게 제조된 분말은 SEM, XRD, PSA, BET 등을 이용하여 비교분석 하였다.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2022.10a
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• pp.385-386
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• 2022

본 연구는 방폭지역에서 정전기를 측정하는 설비 (EST:Electrostatic Transmitter), 측정 된 정전기를 저감시키는 설비(EES:Electrostatic Elimination System), 방폭지역에서 인체 정전기를 제거시키는 설비(방폭 디지털 제전봉)를 통한 비방폭구역에서 사용되는 정전기 측정장비와의 비교를 통하여 극히 제한적인 Basic Design(온도/압력/속 도/유량)으로 인한 설계나 장치 등 변경 등을 반영하여 방폭지역에대한 근본적인 문제점을 도출 제거할수 있는 방안을 마련했으며 기존 사용되었던 비방폭지역의 정전기 제거 시스템을 보완한 방폭지역의 정전기 화재폭발 예방 기술을 적용하였다.

• Explosives and Blasting
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• v.24 no.2
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• pp.41-50
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• 2006

Excavation by explosives blasting necessarily involves noise and vibration, which is highly prone to face claims on the environmental and structural aspects from the neighbors. When the blasting carried out in the vicinity of a structure, the effect of blasting vibration on the stability of the structure should be carefully evaluated. In the conventional method of evaluation, an equation for blast vibration is obtained from test blasting which is later used to determine the amount of charge. This method, however, has limitations in use since it does not consider topography and change in ground conditions. In order to overcome the limitations, dynamic numerical analysis is recently used in continuum or discontinuous models, where the topography and the ground conditions can be exactly implemented. In the numerical analysis for tunnels and rock slopes, it is very uncommon to simulate multi-hole blasting. A single-hole blasting pressure is estimated and the equivalent overall pressure at the excavation face is used. This approach based on an ideal case usually does not consider the ground conditions. And this consequently results in errors in calculation. In this presentation of a case study, a new approach of using blast waves obtained in the test blast is proposed. The approach was carried out in order to improve the accuracy in calculating blasting pressure. The stability of a structure in the vicinity of a slope blasting was examined using the newly proposed method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.3
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• pp.825-831
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• 1996

Using the two-dimensional hydrocode HI-DYNA2D, a calculation on the explosive selding of dissimilar plates(Steel Titanium) was made for the pressure, temperature, velocity and impact ingles adjacent to the collision point during the welding process. The FEM result indicates that optimal stand-off distance of initially parallel set-up is 3-5mm for various values of the explosive thickness. The calculation shows that when the explosive thickness is around 30mm, the temperature of welding point which is strongly related to the metallic jet formation is 2, 000-3, 500K for the given stand-off distance.

• Journal of the Korean Institute of Gas
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• v.9 no.2 s.27
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• pp.1-7
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• 2005

The thermochemical parameters for safe handling, storage, transport, operation and process design of flammable substances are explosive limit, flash point, autoignition temperature, minimum oxygen concentration, heat of combustion etc.. Explosive limit and autoignition temperature are the major physical properties used to determine the fire and explosion hazards of the flammable substances. Explosive limit and autoignition temperature of methane fur LNG process safety were investigated. By using the literatures data, the lower and upper explosive limits of methane recommended 4.8 vol$\%$ and 16 vol$\%$, respectively. Also autoignition temperatures of methane with ignition sources recommended $540^{\circ}C$ at the electrically heated cruicible furnace (the whole surface heating) and recommended about $1000^{\circ}C$ in the local hot surface. The new equations for predicting the temperature dependence and the pressure dependence of the lower explosive limits for methane are proposed. The values calculated by the proposed equations were a good agreement with the literature data.