• Journal of the Korean Society of Safety
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• v.28 no.3
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• pp.63-68
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• 2013

This paper is aimed to make an analysis on characteristics of the parallel arc waveform and RMS of current at the electrical tracking state by conductive powder. In order to achieve the goal in this paper, field state investigation at metal processing companies in Chung-Nam province area was conducted. With the field state investigation, conductive powder were collected from metal processing companies. By experiment on electrical connector(breaker, connector) over which the conductive powder were scattered, arc waveform and RMS of current were measured. The measured waveform and RMS(root-mean-square) of current were analyzed to describe characteristics and patterns of electrical arc by the conductive powder. It was proved that conductive powder on electrical connector can flow electrical current enough to make electrical fire with high thermal energy. Also the change of sine waveform and RMS of current can be used to find out relationship between electrical fire and fault signal by conductive powder. The results obtained in this paper will be very helpful for the prevention of electrical fires occurred at the metal processing companies.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2009.04a
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• pp.358-364
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• 2009

본 연구에서는 우리나라 주요 침엽수종인 소나무(Pinus densiflora)와 활엽수종인 굴참나무(Quercus variabilis)의 낙엽에 대해 FTIR(Fourier Transform Infrared) 분광계를 이용하여 배출 연소가스 종류 및 농도를 측정하였다. 실험결과 소나무와 굴참나무 낙엽에서 Carbon monoxide, Carbon dioxide, Acetic acid, Butyl acetate, Ethylene, Methane, Methanol, Nitrogen dioxide, Ammonia, Hydrogen Fluoride, Sulfur dioxide, Hydrogen bromide 등 13개 연소가스가 검출되었고 굴참나무 낙엽에서는 Nitrogen monoxide가 추가로 검출되었다. 방출된 연소가스의 전체 농도는 소나무 낙엽이 굴참나무 낙엽에 비해 4.5배 많이 검출되었다. 특히, 시간가중평균가스농도(TWA : Time-weighted average, ppm) 기준을 초과하는 연소가스는 Carbon monoxide, Carbon dioxide, Butyl acetate가 검출되었고 단시간노출기준(STEL : Short Term Exposure Limit, ppm) 기준을 초과하는 연소가스는 Carbon monoxide, Carbon dioxide로 소나무 및 굴참나무 모두에서 나타났다. 이에 산불에서의 낙엽층 지표화 연소시 전체 가스 방출량의 99% 이상을 차지하고 있는 Carbon monoxide, Carbon dioxide의 건강 위험성이 높은 것으로 나타났다. 하지만, 검출된 다른 건강 위험성 가스의 경우에도 연소물질의 양이 증가할수록 연소가스의 농도가 높아져 건강안정성에 해가 있을 것으로 판단되며 또한 검출된 연소가스 중 나무의 주요구성 원소가 아닌 Bromide, Fluoride 화합물에 대해서는 토양으로부터의 오염 또는 분석과정에서의 노이즈로 인한 검출 등에 대한 보다 면밀한 검토가 필요할 것으로 판단된다.

• Journal of the Korea Safety Management & Science
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• v.18 no.4
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• pp.99-105
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• 2016

This study was conducted to develop a dummy in an environment similar to the human body, to prepare a standard for evaluation and to present the process of the production in order to evaluate the performance of the robot that can detect the persons needing rescue in a confined space, who are difficult for fire-fighting officials to rescue in case of fire and disaster. As a result, a standard for evaluation was developed and standardized into four parts 'Normal,' 'Risk Stage 1,' 'Risk Stage 2' and 'Risk Stage 3'based on the number of breath cycles, carbon dioxide concentration, core temperature and criteria for hearing to recognize the voice. In addition, in order to produce a dummy, fever, breathing capacity and voice output function were compared and analyzed. This study has significance that it built up basic data of the method of producing the actual dummy, by presenting characteristics and controlling methods using the waterproof insulation heating coil for the function, solenoid valve for the consecutive output of breathing capacity and USB program sound board for voice output.

• Nuclear Engineering and Technology
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• v.51 no.7
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• pp.1765-1775
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• 2019

Multiple spurious operations (MSOs) mean multiple fire induced circuit faults causing an undesired operation of one or more systems or components. The Nuclear Energy Institute (NEI) of the United States published NEI 00-01 as guidelines for solving MSOs. And this guideline includes MSO scenarios of pressurized water reactor (PWR) and boiling water reactor (BWR). Nuclear power plant operators in U.S. analyzed MSOs under MSO scenarios included in NEI 00-01 and operators of PWRs in Korea also analyzed MSOs under the scenarios of NEI 00-01. As there are no pressurized heavy water reactors (PHWRs) in the United States, MSO scenarios of PHWRs are not included in the NEI 00-01 and any feasible scenarios have not been developed. This paper developed MSO scenarios which can be applied to PHWRs by reviewing the 63 MSO scenarios included in NEI 00-01. This study found that seven scenarios out of the 63 MSO scenarios can be applied and three more scenarios need to be developed.

• Journal of Environmental Health Sciences
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• v.46 no.5
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• pp.555-564
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• 2020

Objectives: To identify and investigate through qualitative and quantitative analysis the hazardous substances generated when compressed wood was burned at a live fire-training center. Methods: Four types of compressed wood that are actually used in live fire training were burned in a chamber according to KS F2271. The gaseous material was sampled with a gas detector tube and conventional personal samplers. Results: 1,3-butadiene, benzene, toluene, xylene, formaldehyde, hydrogen chloride, hydrogen cyanide, ammonia, carbon monoxide, and nitric acid were detected. In particular, 1,3-butadiene (497.04-680.44 ppm), benzene (97.79-125.02 ppm), formaldehyde (1.72-13.03 ppm), hydrogen chloride (4.71-15.66 ppm), hydrogen cyanide (3.64-8.57 ppm), and sulfuric acid (3.85-5.01 ppm) exceeded the Korean Occupational Exposure Limit as measured by sampling pump according to the type of compressed wood. Conclusions: We found through the chamber testing that firefighters could be exposed to toxic substances during live fire training. Therefore, firefighter protection is needed and more research is required in the field.

• Fire Science and Engineering
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• v.16 no.3
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• pp.12-15
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• 2002

It has long been recognized that exposure to fire-induced toxic gases is a fatal hazard confront-ing people in fires. In this study, an indoor fire experiment was conducted in an unoccupied residential building located in An-san city, Kyoung-gi province, and the composition of effluent gases, which include CO, $CO_2$, $O_2$, $SO_2$, NO and $NO_2$, were measured by a gas analyzer. A group of lab rats were exposed to the toxic gases released from fire, and the blood samples of the rats were gathered every 2 minutes. A toxicity evaluation was conducted by analyzing the concentrations of Glucose, AST(GOT), ALT(GPT), CBC Count and CO(carboxy)-Hb in the blood samples. Shown from the analysis is the does-response relationship between the CO concentration that rats were exposed to and the CO-Hb concentration in rat blood.

• Fire Science and Engineering
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• v.28 no.6
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• pp.8-12
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• 2014

Interior finishing materials using noncombustible were regulated by the building codes to prevent the spread of fire and protect occupants. The average deed of stopping time of experimental mouse exposing combustion gas were measured by KS F 2271 gas toxicity test. At that time, The average deed of stopping time under 9 minutes were judged a inconsistence. This experiment method has limit to find out a cause of toxicity effect factor. In this study, particle size analysis were performed for investigate a major factor.

• Fire Science and Engineering
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• v.33 no.3
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• pp.9-20
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• 2019

This study was examined fire risk properties of wood specimen for the constructional interiors, especially focusing on the fire performance index (FPI) and the fire growth index (FGI) as heat hazard characteristics. Flame retardants were synthesized using boric acid, boronic acid and tetraethoxyorthosilicate. Heat release characteristics were measured by using a cone calorimeter (ISO 5660-1) and cypress was used. The external heat flux as fire intensity was maintained at 50 kW/㎡. The measured fire performance index (FPI) after burning was increased by 1.6 times for boric acid/silicone (BA/Si) sol, each 1.1 times for isobutylboronic acid/silicone (IBBA/Si) sol and phenylboronic acid/silicone (PBA/Si) sol compared with cypress. Fire risk by the fire performance index was increased BA/Si, IBBA/Si ≈ PBA/Si order. The fire growth index was decreased 94% for the BA/Si and 8% for the IBBA/Si sol, and was increased by 17% for the PBA/Si sol. Fire risk by the fire growth index was increased BA/Si, IBBA/Si, PBA/Si order. Overall fire risk was higher in the order of BA/Si < IBBA/Si < PBA/Si.

• Applied Chemistry for Engineering
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• v.32 no.4
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• pp.417-422
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• 2021

In this study, poly isocyanurate foam (PIR), poly urethane foam (PUR), and phenol foam (PF) of organic insulation materials were selected, and investigated using a cone calorimeter, as per ISO 5660-1. Standard materials (PMMA) were used to standardize the fire hazard assessment, and the fire risk was classified and evaluated by Chung's equations-III and IV. The fire performance index-II value of Chung's equations-II was the highest value with PF of 14.77 s²/kW. And the PUR was 0.08 s²/kW, the lowest value of fire performance index-II value. The fire growth index-II value was the lowest value with PF of 0.01 kW/s². And the PUR was 1.14 kW/s², the highest value of fire growth index-II value. The fire performance index-III (FPI-III) of Chung's equations-III had the lowest value for PUR (0.11) and the highest for PF (20.23). The PUR showed the highest value of the fire growth index-III (FGI-III) as 14.25, while the PF exhibited 0.13 regarded as the safest materials. The fire risk index-IV (FRI-IV) value of Chung's equation-IV was in the following order: PUR (130.03) >> PIR (19.13) > PMMA (1.00) > PF (0.01). Therefore, it was concluded that the fire risk associated with PF is the lowest, whereas that associated with PUR is the highest.

• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.229-236
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• 2022

An experimental investigation was conducted on the influences of median size, dust concentration, dust condition (cloud and layer) for the fire and explosion hazard assessment of dusts with the same powder property. For this purpose, tests have been performed in accordance with 20 L explosion sphere, thermogravi- metric analyze, combustion rate tester (UN method). We investigated the explosion characteristics and flame propagation velocity (FPV) in dust cloud and the flame spread velocity(FSV) over dust layer on 8 dust samples with different particle sizes of 4 types of dusts (Sugar, Mg, Al, Zr). An explosion hazard increased with decreasing particle size in Mg and Al dust clouds, but sugar did not show the effect of explosion hazard due to particle size change in dust clouds. The flame propagation velocity (FPV) of suspended dusts increased significantly when the particle size decreased from micro to nano than the variation of particle size in micro range. The flame spread velocity (FSV) over dust layer showed a tendency to increase over the inclined dust layers (30° slope) rather than the horizontal dust layers (0° slope). The flame spread rate (FSV) over dust layers increased on the inclined dust layer (30° slope) rather than the horizontal dust layer (0° slope) and was higher upward flame than the downward flame in condition of inclined dust layers(30° slope).