• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1999.06a
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• pp.39-44
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• 1999

최근 들어 산업설비 및 건축물의 대형화, 다 기능화 추세가 두드러지게 나타나고 있는 가운데 화재발생으로 인한 인명 및 재산상의 피해규모가 비례적으로 증가하고 있다. 이에 화재의 근원적 원인과 발생 가능성을 미연에 방지하는 방화ㆍ방폭 기술의 개발이 무엇보다도 중요해지고 있다. 또한 화재예방이 불가능하였을 경우 신속한 화재감지를 통해 화재진압에 나서는 것과 화재특성을 분석하여 화재를 방지하는 것 역시 중요해지고 있다. (중략)

• 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)

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.2
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• pp.451-457
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• 2017

The numerical analysis was conducted to evaluate the behavior of slab-column connection subjected to blast loads using LS-DYNA. The typical form of slab-interior column connection for analysis was considered as a reference specimen and the drop panel slab-interior column was designed to verify the effects of drop panel. The slab-column connections, which were composed of interior, edge and corner column, were additionally analyzed to compare their confinement effects of specimens. Analysis results were contained the failure shape of connection, behavior of member and so on. From the results, the blast-resistant capacities of slab-column connection would be enhanced by reinforcing the drop panel. In addition, the performance of connections could be improved, when the confinement effects were enhanced.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.11
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• pp.690-695
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• 2014

In this paper, we develop a explosion-proof LED lighting (Ex circuit) circuit of Explosion-proof LED Signal Lamp (Ex LSL) to utilize the core module of the explosion-proof Local Control System (Ex LCS) for offshore plant applications. And then analyzed its electrical, optical and thermal characteristics. Ex circuit was applied input voltage from AC/DC(12~254) V. In this experiments, stable light-on characteristics were confirmed by eyes for the every input voltages with min. 78,462 and max. $517,975cd/m^2$ of luminance. also Output current and output luminance was made proportional. Because the measured maximum surface temperature of Ex circuit was $54.23^{\circ}C$ at AC 48 V, Ex circuit was rated with T6 of temperature class. Finally, Ex circuit was shown stable light on characteristics under the $-50^{\circ}C$ and $60^{\circ}C$ during 12 hours of test period.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.14 no.3
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• pp.21-28
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• 2018

This paper presents two-step simulations to calculate the influence of blast-induced pressures on explosion-protection valves installed at the boundary between a protection facility and a tunnel entering the facility. The first step is to calculate the respective overpressure on the entrance and exit of the tunnel when an explosion occurs near the tunnel entrance and exit to approach the protection facility. Secondly, the blast pressures on the explosion-protection valves mounted to walls located near the tunnel inside approaching the protection facility are analyzed with a 0.1 ms time variation using the results obtained from the first-step calculations. The following conclusions could be derived as a results: (1) The analysis of the entrance tunnel scenario, P1, leads to the maximum overpressure of 47 kPa, approximately a half of the ambient pressure, at the inner entrance due to the effect of blast barrier. For the scenario, P2, the case not blocked by the barrier, the maximum overpressure is 628 kPa, which is relatively high, namely, 5.2 times the ambient pressure. (2) It is observed that the pressure for the entrance tunnel is effectively mitigated because the initial blast pressures are partially offset from each other according to the geometry of the entrance and a portion of the pressures is discharged to the outside.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.6
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• pp.88-94
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• 2015

Large-scale petrochemical and power plants has increased demanting wireless technology for continuous monitoring. However, the current USN technologies, such as ZigBee and Bluetooth, are lackof reliability and security. Therefore, there is a strong need to apply a new wireless technology standard of the ISA. In this study, a petrochemicalplant safety management system based on the ISA wireless transmitter isdeveloped. ISA100.11a communication module and LTE communication module equippedwith an explosion-proof wireless transmitter are developed. A petrochemicalplant safety management system is built based on the IoT technologies. Thedeveloped system is verified through a wide range of testing and thus, on-siteapplicability is proved.

• Fire Science and Engineering
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• v.18 no.1
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• pp.18-23
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• 2004

This paper describes the minimum ignition limits for propane-air 5.25 Vol.% mixture gases in low voltage inductive circiuts. The improved effects on the ignition limit are studied by parallel safety components(resistors) for propane-air 5.25 Vol.% mixture gas in low voltage inductive circuits. The experimental devices used in this test are the IEC type spark ignition test apparatus. The minimum ignition limits are controlled by the values of current in inductive circuit. Energy supplied from electric source is first accumulated at the inductance, it's extra energy is working as ignition source of the explosive gas. The improved effects on the ignition limit are respectively obtained as the maximum rising rate of 330% by composing parallel circuits between inductance and resistor as compared with disconnecting inductance with the safety components. The more values of inductance increase the higher improved effects of ignition limit rise. The less values of resistor the higher improved effects of ignition limit rise. It is considered that the result can be used for not only data for researches and development of intrinsically safe explosion-proof machines which are applied equipment and detectors used in dangerous areas but also for datum for its equipment tests.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.17 no.4
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• pp.79-90
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• 2021

This paper presents a study to reduce the effect of blast pressure on the blast valves installed in protection tunnels, where the shape of the tunnel entrance and the blast pocket is optimized based on the predetermined basic shape of the protective tunnels. The reliability of the numerical tunnel models was examined by performing analyses of mesh convergence and overpressure stability and with comparison to the data in blast-load design charts in UFC 3-340-02 (DoD, 2008). An optimal mesh size and a stabilized distance of overpressure were proposed, and the numerical results were validated based on the UFC data. A parametric study to reduce the blast overpressures in tunnel was conducted using the validated numerical model. Analysis was performed applying 1) the entrance slope of 90, 75, 60, and 45 degrees, 2) two blast pockets with the depth 0.5, 1.0, and 1.5 times the tunnel width, 3) the three types of curved back walls of the blast pockets, and 4) two types of the upper and lower surfaces of the blast pockets to the reference tunnel model. An optimal solution by combining the analysis results of the tunnel entrance shape, the depth of the blast pockets, and the upper and lower parts of the blast pockets was provided in comparison to the reference tunnel model. The blast overpressures using the proposed tunnel shape have been reduced effectively.

• Explosives and Blasting
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• v.40 no.4
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• pp.1-14
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• 2022

To review the appropriateness of current regulations on the simple explosive storage facility, the effects of internal explosion on the structural stability of the standard storage facility were analyzed by means of both FEM analyses and field experiments. As a result, it was found that the explosion-proof performance of the existing storage structure was not sufficient for 15 kg of emulsion-type explosive. Thus, an alternative method of splitting explosives was tested by conducting sympathetic detonation experiments. This method worked properly as expected, and the proper amount of splitted explosive was determined according to the test results. In addition, a storage structure with open ceiling was found to be very effective because explosion pressure was released so rapidly that the damage of the facility could be reduced significantly. Hence, such a structural pattern was proposed as a new design scheme for simple explosive storage facility.

• Journal of the Korean Society of Safety
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• v.28 no.2
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• pp.31-36
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• 2013

For lighting of dark and hazardous workplace such as compartment of ships under construction, workers should use hand lamps of explosion-proof type. However, the heavy weight of such lamps has prevented most impatient workers from using such types of lamps extensively. In this paper, we developed a light weight hand lamp of intrinsic safety type which reduced the weight a lot while maintaining or improving the lighting and explosion-proof function. We made a prototype which consisted of lamp fixture and high frequency power supply. Testing results show that the hand lamp meets well all the explosion-proof testing requirements of the Korea Occupational Safety and Health Agency. And more, we surveyed the explosion protection technology of a light weight hand lamp, and suggested the advantage/disadvantage to apply lighting of hand lamp about economical aspect.