단백포소화약제의 유동성 변화에 따른 소화 특성

신창섭 ( Changsub Shin ),정현정 ( Hyun Jeong Jeong ) 한국안전학회(구 한국산업안전학회) 2014 한국안전학회지 Vol.29 No.2

Foam extinguishing agent is widely used for extinguishing combustible liquid fires. Compared to other foam type extinguishing agents, protein foam has relatively low cost and low toxicity and produces stable foam blanket which is excellent in heat resistance and sealability, despite it has weak fluidity. Therefore the study investigated foaming characteristics followed by various factors affecting the fluidity of the protein foam extinguishing agent. The extinguishing characteristics differentiated by the changes in fluidity were also experimented. Foaming performance was compared by measuring the expansion ratio and the 25% drainage time. Moreover, the 25% drainage time and the extinguishing time was compared. The results showed that the 25% drainage time and the expansion ratio were increased as the pressure of nozzle and the concentration of hydrolyzed protein liquid enlarged. However the foaming and extinguishing performance were not improved when the condition exceeded certain level of pressure and concentration. The fastest fire extinguishing condition was the nozzle pressure 4bar with the 85wt.% of concentration of hydrolyzed protein liquid.

미세물분무의 소화성능 개선을 위한 증점제(잔탄검)의 영향

김승일,신창섭,Kim. Seungil,Shin. Changsub 한국방재학회 2013 한국방재학회논문집 Vol.13 No.5

물은 다양한 소화효과를 지니고 있는 경제성 있는 소화약제임에도 점성이 상대적으로 낮아 방사시 화재표면에 점착하지 못함으로 인한 소화효과의 감소 및 손실되는 물, 물로 인한 2차 피해의 단점도 있다. 본 연구에서는 이러한 단점을 보완하고자 증점제인 잔탄검을 첨가하였으며 이를 미세물분무 노즐을 사용하여 목재화재 및 헵탄화재에 적용시켜 소화성능을 개선해 보고자 하였다. 실험결과 목재화재에 적용시킨 경우에는 0.2 MPa의 방사압에서 잔탄검 수용액 농도 0.2%가 순수 물에 비해 화염억제시간 및 소화시간이 각각 7.9배, 2.9배 빨랐으며 헵탄화재에 있어서는 잔탄검 수용액 농도 0.025%가 순수 물에 비해 약 5.2배 빠른 소화시간을 나타내었지만 이후의 증점된 농도에서는 소화에 실패하였다. 또한 소화에 필요한 물소모량도 소화시간에 비례하여 감소하였으며 방사압 증가에 따른 목재 및 헵탄화재의 소화성능도 향상되는 것을 알 수 있었다. Water is an economical extinguishing agent and has a variety of extinguishing effect. Since water does not adhere to the fire surface due to low viscosity, which causes to reduce extinguishing effect, secondary damage to unburned materials and loss of water. In this study, xanthan gum as a viscosity agent added to water and using water mist nozzle xanthan gum solution applied to wood crib fire and heptane fire to improve extinguishing performance. The results show that in case of wood crib fire in 0.2 MPa, flame suppression time and fire extinguishing time of xanthan gum 0.2% solution are 7.9 times, 2.9 times shorter than pure water, respectively. In heptane fire, fire extinguishing time of xanthan gum 0.025% solution is 5.2 times shorter than pure water in 0.2MPa, but extinguishing is failed after concentration of xanthan gum increase. Also, it is identified that water consumption decrease with extinguishing time and extinguishing performance of xanthan gum on wood crib fire and heptane fire improved according to increase of discharge pressure.

스프링클러 헤드의 방수상수에 따른 물방울 크기에 관한 실험적 연구

허민녕,신창섭,Hur, Min Noung,Shin, Changsub 한국안전학회 2017 한국안전학회지 Vol.32 No.4

The sprinkler system is a basic fire extinguishing system that uses water as an extinguishing agent. In order to evaluate the fire extinguishing performance of the sprinkler system, information such as the discharge angle, discharge speed, discharge pressure, flow rate, and water droplet size of the installed head are required. However, there is a lack of research on droplets size compared to other requirements. In this study, to evaluate the extinguishing characteristics of sprinkler system, the droplet size distribution was measured for various types of sprinkler heads actually used. The size of the droplet was measured using laser diffraction method. The 50% cumulative volume distribution ($D_{v50}$) according to discharge coefficient(K factor) was $540{\mu}m{\sim}695{\mu}m$ for K50, $542{\mu}m{\sim}1,192{\mu}m$ for K80, $980{\mu}m{\sim}1,223{\mu}m$ for K115 and $1,188{\mu}m{\sim}1,234{\mu}m$ for K202. Based on the measured results, the vaeiance of the droplet particle distribution and the distribution ($D_{v50}$) according to discharge coefficient(K factor) was $540{\mu}m{\sim}695{\mu}m$ for K50, $542{\mu}m{\sim}1,192{\mu}m$ for K80, $980{\mu}m{\sim}1,223{\mu}m$ for K115 and $1,188{\mu}m{\sim}1,234{\mu}m$ for K202. Based on the measured results, the vaeiance of the droplet particle distribution and the Rosin-Rammler index value are presented. As a result of the fire simulation with FDS, it was confirmed that the performance difference occurs according to the water droplet size distribution even when the same amount of water is used. Therefore, the extinguishing performance of the sprinkler system should be evaluated considering the droplet size distribution according to the sprinkler head type.

불화수소 누출사고 비교를 통한 하역작업장의 안전성 향상방안에 관한 연구

우종운(Jongwoon Woo),신창섭(Changsub Shin) 한국가스학회 2018 한국가스학회지 Vol.22 No.4

본 연구는 불화 수소 탱크 컨테이너 하역장에서 불화수소 누출 시 누출량 및 확산 정도를 정량적으로 평가하여 동종사고의 재발을 방지하고 안전성 향상방안을 제시하는데 목적이 있다. 2012년 H사에서는 최대 저장량이 18 Ton인 탱크컨테이너에서 누출사고가 발생하여 인근 지역으로 8 Ton이 누출되었고, 그로인해 사회적 이슈가 되었다. 가우시안 플럼(Gaussian plume) 모델을 이용하여 계산한 결과 누출지점으로부터 반경 1,321m까지의 농도가 20ppm 이상으로 예측되었다. 2014년 R사에서 발생한 불화수소 누출사고에서는 누출량이 11.02kg으로 추정되었고, 그 중 2.9㎏이 세정기로 회수되었다. 가우시안 플럼 모델을 사용하여 계산 한 결과, 누출 원으로부터 20ppm 이상의 농도를 갖는 피해 범위가 반경 69m로 예상되었다. 위의 두 가지 사고를 비교 한 결과, 누출량은 약 987배 차이가 발생했고, 피해 지역은 19 배 이상 차이가 나는것으로 나타났다. 따라서 보호구의 착용, 하역 장소의 밀폐 및 세정기 설치, 그리고 비상훈련을 실시하여 하역장에서 불화수소가 대량으로 누출되는 사고가 발생하지 않도록 관리해야 한다는 결론을 얻었다. The purpose of this study is to assess quantitatively the amount of leaks and the extent of dispersion in case of a leak at a hydrogen fluoride tank container unloading station, and to suggest a safety improvement plan to prevent recurrence of similar accidents. In 2012, Company H leaks 8 tonnes of tank containers with a maximum storage capacity of 18 Ton, causing it to become a social issue. As a result of calculation using Gaussian plume model, the concentration was estimated to be more than 20ppm from the leak point to 1,321 m radius. The leakage of hydrogen fluoride from the company R in 2014 was estimated to be 11.02 ㎏, of which 2.9 ㎏ was treated by the scrubber. As a result of calculation using Gaussian plum model, the damage range with a concentration of 20ppm or more from the leak source was estimated to be 69 m in radius. As a result of comparing the above two accidents, it was found that the leakage amount was about 987 times different and the damaged site was more than 19 times different. Therefore, it was concluded that it was necessary to control the wearing of the protective equipment, the enclosure of the unloading site, the installation of the scrubber, and the emergency training to avoid the accidental leakage of a hydrogen fluoride from the unloading site.

화재대피용 방독마스크 정화통 적용을 위한 $CO_3O_4/{\gamma}-Al_2O_3$ 촉매 특성 연구

김덕기,김복희,신채호,신창섭,Kim Deogki,Kim Bokie,Shin Chae-Ho,Shin Changsub 한국안전학회 2004 한국안전학회지 Vol.19 No.4

[ $CO_3O_4/{\gamma}-Al_2O_3$ ] catalysts were reported high activity on the low temperature CO oxidation. The effects of the calcination temperature, the loaded amount of cobalt and the oxygen concentration on the characteristics of CO oxidation have been investigated for a emergency escape mask cartridge. $Co(NO_3)_2\cdot6H_2O$ was used as cobalt precursor and the catalysts were prepared by incipient wetness impregnation. TGA shows that enough calcination is accomplished at $450^{\circ}C$ and cobalt phase is $Co_3O_4$ after calcination in the temperature range of $300\ ~500^{\circ}C$. The specific surface area and pore volume of catalysts are decreased with increasing of loaded amount of cobalt. And with the increase of loaded amount of cobalt and the oxygen concentration, the catalytic activity is increased.

선박화재 적용 단백포 소화약제의 안정제에 따른 소화특성

이응우 ( Eungwoo Lee ),신창섭 ( Changsub Shin ) 한국안전학회(구 한국산업안전학회) 2015 한국안전학회지 Vol.30 No.4

Onboard fire extinguishing system is important to protect cargo and human lives and every oil tanker has foam type fire extinguishing system. Because of environmental problem, agent which contains materials such as Perfluorinated compounds are regulated and the development of the environmental friendly agent is required. The protein foam has less environmental pollution problem and has an excellent fire extinguish performance to oil fire. In the research, bivalency metal salts were added as stabilizer to increase fire resistance and stability of the foam. Ferrous sulfate, Iron chloride and Nickel chloride were used and to adjust to vessel, sea water was applied. As a stabilizer increased, the expansion ratio was raised. However 25% drainage time was decreased over 2.0 wt.% which is knowable that the foam brokes easily. The amount of generated foam was measured to check fluidity of foam and it appeared that when FeSO₄ 1.2 wt.% was added, the amount of generated foam reached large and also the 25% drainage time was high. To evaluate the fire extinguishing performance for oil fire, the small scale oil fire test was executed. When FeSO₄ 1.2 wt.% was added, fire extinguishing time was in its shortest which informs fluidity of foam and stability are important factors on fire extinguishing efficiency.

폴리실리콘 제조 공정에서 화학물질 누출 시 피해범위에 관한 연구

우종운(Jongwoon Woo),신창섭(Changsub Shin) 한국가스학회 2018 한국가스학회지 Vol.22 No.4

지구온난화로 인하여 태양광 발전에 대한 관심이 커지고 있다. 이에 따라 태양전지를 만드는 핵심물질인 폴리실리콘의 수요도 나날이 증가하고 있으며 시장이 커짐에 따라 생산공정에서 크고 작은 사고들이 발생하고 있다. 그 예로 2013년 상주시의 폴리실리콘 제조공장에서 염산이 누출되었고 2014년에는 여수시의 폴리실리콘 제조공장에서 화재가 발생하였으며, 2015년에는 군산시의 폴리실리콘 제조공장에서 STC(Silicon Tetrachloride)가 누출되었다. 이러한 누출 사고들은 사업장 내부에만 영향을 주는 것이 아니라 인근지역까지 영향을 줄 수 있다는 것이 특징이다. 따라서 본 연구에서는 폴리실리콘 제조공정에서 사용되는 위험물질을 파악하고, 최악의 누출 시나리오를 적용했을 때 누출량과 피해범위를 정량적으로 예측하였다. 그 결과 폭발에 따른 피해거리는 726 m로 예측되었고, 독성에 대한 피해거리는 4,500 m로 예측되었다. 그리고 TCS(Trichlorosilane), STC(Silicon Tetrachloride), DCS(Dichlorosilane)가 누출되어 공기 중의 수분과 반응하여 HCl이 생성될 경우 피해 거리는 최대 5.7 ㎞까지로 예측되었다. There is growing interest in solar power generation due to global warming. As a result, demand for polysilicon, which is the core material for solar cells, is increasing day by day. As the market grows, large and small accidents occurred in the production process. In 2013, hydrochloric acid leaked from the polysilicon manufacturing plant in SangJu. In 2014, a fire occurred at a polysilicon manufacturing plant in Yeosu, and in 2015, STC(Silicon Tetrachloride) leaked at a polysilicon manufacturing plant in Gunsan City. Leakage of chemicals in the polysilicon manufacturing process can affect not only the workplace but also the surrounding area. Therefore, in this study, we identified the hazardous materials used in the polysilicon manufacturing process and quantitatively estimate the amount of leakage and extent of damage when the worst case scenario is applied. As a result, the damage distance by explosion was estimated to be 726 m, and the damage distance to toxicity was estimated to be 4,500 m. And, if TCS(Trichlorosilane), STC(Silicon Tetrachloride), DCS(Dichlorosilane) leaks into the air and reacts with water to generate HCl, the damage distance is predicted to 5.7 ㎞.

무선 센서네트워크 기반 차량속도 측정 시스템

유성은,김태홍,박태수,김대영,신창섭,성경복,Yoo, Seongeun,Kim, Taehong,Park, Taisoo,Kim, Daeyoung,Shin, Changsub,Sung, Kyungbok 대한임베디드공학회 2008 대한임베디드공학회논문지 Vol.3 No.1

The architecture of WSN based Vehicle Speed Measurement System is presented in this paper from Telematics Sensor Network(TSN) to Management System. To verify the feasibility of the system, we implemented the vehicle speed measurement system and evaluated the accuracy of velocity measured by the system in our testbed, an old highway located near Kyungbu highway. The system performed over 95% of accuracy at 80kmph from the measurement. In addition, the battery life time of the sensor node was evaluated by simulation analysis with real measured current consumption profiles. Assuming the maximum average daily traffic in 2005, the battery life time is expected to be over 1.6 year from the simulation result.

안면부 여과식 방진 마스크의 형태 및 착용 방법 교육이 밀착계수에 미치는 영향 비교

어원석 ( Won Souk Eoh ),최영보 ( Youngbo Choi ),신창섭 ( Changsub Shin ) 한국안전학회(구 한국산업안전학회) 2016 한국안전학회지 Vol.31 No.5

Particulate filtering facepiece respirators (PFFR) is one of the most widely used items of personal protective equipments, and a tight fit of the respirators on the wearers is critical for the protection effectiveness. In order to effectively protect the workers through the respirators, it is important to find and evaluate the ways that can be readily applicable at the workplace to improve the fit of the respirators. This study was designed to evaluate effects of mask style (cup or foldable type) and donning training on fit factors (FF) of the respirators, since these are available at various workplace, especially at small business workplace. A total of 40 study subjects, comprised of 30~50s aged male and female workers in metalworking industries, were enrolled in this study. The FF were quantitatively measured before and after training related to the proper donning and use of cup or foldable-type respirators. The pass/fail criterion of FF was set at 100. After the donning training for the cup-type mask, subjects who passed the fit test were increased from 10 to 33. Moreover, the geometric mean (GM) of FF was increased by 340% in subjects who failed the test. In addition, the training effects for the cup-type mask were significant in female and 50s aged subjects. On the other hand, although the GM of FF for the foldable-type mask was also increased after the donning training, the GM of FF for the foldable-type mask and it’s increase rate were smaller as compared to the cup-type mask. Furthermore, the differences of the increase rates of the GM of FF in sex and aged of the subjects were not significantly for the foldable-type mask. The multi-distribution of leak points for the foldable-type mask may be one of causes for the less effect of training on the fit of the foldable-type mask. These results imply that the raining on the donning and use of PFFR can enhance the protection effectiveness of cup or foldable-type mask, and that the training effects for the foldable-type mask is less significant than that for the cup-type mask. Therefore, It is recommended that the donning training and fit tests should be conducted before the use of the PFFR, and that efficient tranining programs for the foldable-type mask are required.

알칼리금속염을 함유한 미분무수 소화약제

김민형 ( Minhyung Kim ),이주혁 ( Joohyuk Lee ),신창섭 ( Changsub Shin ) 충북대학교 산업과학기술연구소 2016 산업과학기술연구 논문집 Vol.30 No.1

The extinguishing experiment was performed using the alkali as an additive to improve the performance of the low ressure water mist fire extinguishing system. KHCO3 and NaHCO3 were used as alkali metallic salts, and extinguishing time and amount of water ejected were measured for class A fire. In case of using additives, the fire extinguishing time was shorter than that of pure water at a given discharge pressure and the amount of water ejected was also reduced. It was because of the momentum increase of a water droplet containing additives and the chemical extinguishing effect. By using alkali metal agent, the extinguishing time and improvement of the consumption of water can be reduced.