• Title/Summary/Keyword: Extinguishing concentration

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A Study on Assessment of Fire and Evacuation Safety in Environmental Energy Facilities (환경에너지시설의 화재 및 피난 안전성 평가에 관한 연구)

  • Jeon, Yong-Han;Han, Sang-Pil
    • Journal of the Korea Safety Management & Science
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    • v.21 no.4
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    • pp.39-44
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    • 2019
  • In this study, fire and evacuation safety of environmental energy facilities using fire and evacuation simulation was examined as part of performance-oriented design. The worst-case fire scenarios in which fire-fighting facilities such as sprinkler fire extinguishing and smoke control systems are not working, and the FDS analyzes the visibility, temperature distribution, and carbon monoxide concentration distribution through FDS. The safety was examined. As a result, it was proved that evacuation could limit the visibility, temperature, and carbon monoxide concentration in a smooth range, based on the safety standards set by relevant laws. In other words, it was possible to verify the safety of fire and evacuation for environmental energy facilities where a large amount of combustibles and fires coexist.

Influence of Dust Environment on the Detection Capability of Ultraviolet Flame Detector (UV 화염감지기의 감지성능에 대한 분진분위기의 영향)

  • Kim Hong;Hu Rui
    • Journal of the Korean Institute of Gas
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    • v.1 no.1
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    • pp.113-119
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    • 1997
  • The detection capability of UV flame detector in dust environment would be impaired. In this study, an experiment was conducted, in an effort to further understand the behavior of UV flame detector and to evaluate its detection capability in industry dust environment. Detergent powder, coal powder and dry extinguishing agent were selected as dust sources. Flaming sources include propane and gasoline flame. Experiment results indicate that dust can cause remarkable attenuation of UV flame radiation. The concentration of dust and the length of air layer where dust dispersed determine the reduction of radiation intensity. On the other hand, the attenuation of UV radiation also depends on the chemical and Physical properties of dust.

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Experimental Study on Moisture Content According to Addition of Surfactants (계면활성제 첨가에 따른 함수율에 관한 실험적 연구)

  • Kim, Nam-Kyun;Rie, Dong-Ho
    • Fire Science and Engineering
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    • v.29 no.2
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    • pp.79-83
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    • 2015
  • The fire accident is a representative type of disaster that can largely impact on business. Therefore, precautionary measures and rapid initial response is very important when a disaster occurs. The storage of porous combustibles is inevitable in coal yard, plywood processing industry, and others that are currently operating. Initial fire fighting of fire and identifying the ignition point in such a porous combustible storage space are so difficult that if the initial response is failed, being led to deep-seated fire, surface fire is likely to result in secondary damage. In addition, deep-seated fire can cause personal injuries and property damage due to a large amount of toxic gases and reignition. Therefore damage reduction measures is required around the storage space to handle a porous flammable. Improving the penetration performance of the concentration of the surfactant is carried out as underlying study, which is about an deep-seated fire extinguishing efficiency augmentation when using wetting agents. The porous materials used in the experiments is radiata pine wood flour, which occupies more than 75% of the domestic wood market. Fire fighting water is selected as Butyl Di Glycol (BDG), which is being used for infiltration extinguishing agent, and the experiment was carried out by producing a standard solution. The experiment was carried out on the basis of the Deep-Seated Fire Test of NFPA 18. The amount of watering, porous material to the internal amount of penetration, and runoff measurement out of the porous material was conducted. According to experimental results, as the surface tension is reduced, the surfactant concentration macroscopic penetration rate decreases, but infiltration to a porous material is shown to have growth characteristics.

A Numerical Simulation of the Effect of the Injection Angle and Velocity of the $CO_2$ Agent Nozzle on the Characteristics of $CO_2$ Concentration Distribution ($CO_2$ 소화제 노즐 분사각 및 분사속도가 $CO_2$ 농도분포특성에 미치는 영향에 관한 수치적 연구)

  • Park, Chan-Su
    • Fire Science and Engineering
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    • v.20 no.2 s.62
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    • pp.44-53
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    • 2006
  • We have conducted a numerical simulation under two-dimensional unsteady conditions in order to analyze the effect according to the injection angle and velocity of the $CO_2$ agent nozzle which is one of the elements for the fixed type $CO_2$ fire extinguishing system installed in a ship on the characteristics of flow and $CO_2$ concentration distribution. The flow fields and concentration fields were measured and analyzed. We can found that the difference of flow patterns according to the conditions of $CO_2$ agent injection nozzle, and in all the conditions of $CO_2$ agent injection nozzle, the iso-concentration line was expanded from the region at which vortex was generated to the surroundings. We can expected that the intensity of the wall jet on the bottom floor was generated differently and the iso-concentration lines were expanded or shrunk according to the angle of $CO_2$ agent injection nozzle. In case of increasing $CO_2$ agent injection velocity maintaining the flow quantity of the $CO_2$ agent injection equally, the iso-concentration line of $CO_2$ agent on bottom floor can be formed more higher than in case of decreasing $CO_2$ agent injection velocity.

A Technical Description on The Safety Aspects related To Gas Suppression Fire Protection System (가스계 소화시스템관련 안전기술)

  • 이창욱
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2002.05a
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    • pp.21-29
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    • 2002
  • With regard to the personnel safety and other safety when the gas suppressants are discharged into the area where occupants exist, the short term and long term effects to the health of people are discussed mainly with the Carbon dioxide agent and Halon Replacement agents system. To gain the benefits of CO2 extinguishing systems while minimizing risk to people serious attention must be given to personnel safety in the design, installation, and maintenance of CO2 systems. Training of personnel is essential. A major factor in the use of a clean agent fire suppressant in a normally occupied area is toxicity. While all halocarbon agents are tested for long-term health hazards, the primary endpoint is acute or short-term exposure, The primary acute toxicity effects of the halocarbon agents described here are anesthesia and cardiac sensitization. For inert gases, the primary physiological concern is reduced oxygen concentration.

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Characteristics of Water Solutions Containing Nonionic Surfactants and Their Fire Fighting Performance (비이온성 계면활성제가 함유된 수용액의 특성과 소화성능)

  • 이윤우;이윤용;박양원
    • Fire Science and Engineering
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    • v.16 no.3
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    • pp.61-70
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    • 2002
  • A fire extinguishing agent containing non-ionic surfactant which is environmentally friendly and low cost was prepared and tested its characteristics and fire fighting performance. Ethoxylated sorbitol septaoleate, containing 40 moles of ethylene oxide as the primary surfactant, linear ethoxylated secondary alcohol, containing 7-11 moles ethylene oxide as the secondary surfactant, and ethoxylated sorbitol trioleate, containing 40-50 moles of ethylene oxide were used in the agent. It is demonstrated that the water solution containing 6 wt% agent is capable to extinguish gasoline fire when it is put into the fire four times as much as gasoline. According to the field test of class B fire with a unit 1, it is found that the fire fighting performance is directly proportional to the concentration of surfactant in the agent.

Effects of Spray Characteristics of Water Mist on The Extinction of a Liquid Pool Fire (분무수 분무특성이 액체연료 Pool 화염의 소화에 미치는 영향)

  • Kim, Ho-Young;Oh, Sang-Youp;Chung, Jin-Taek
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.12
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    • pp.1591-1599
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    • 2004
  • A series of experiments were conducted to study the effectiveness of the extinction of a liquid pool fire with two different water atomizing nozzles. Fire source is a small-scale circular stainless steel pan of 120mm in diameter with the fuels of hexane and ethanol. K-type thermocouples were used to measure the flame and fuel temperature along the pool centerline and under fuel surface. A digital camera was used to visualize the process of the fire suppression. The experimental results show that water mist droplet size is l15∼180${\mu}{\textrm}{m}$ with nozzle A and 130∼190${\mu}{\textrm}{m}$ with nozzle B. The extinguishing time of pool fire was reduced with the increase of pressure. When water droplets are small, they do not reach the flame base since they may be deflected or evaporated by the fire plume. However, influence of flow rate is more important than droplet size on fire extinction. Among the fire extinction mechanisms, drop of flame temperature is superior to suffocation of $O_2$ concentration.

The Effects of Spray Characteristics of Water Mist on the Fire Suppression of Liquid Pool Fire (미분무수 분무특성이 액체연료 Pool 화염의 소화에 미치는 영향)

  • Oh, Sang-Youp;Kim, Ho-Young;Chung, Jin-Taek
    • 한국연소학회:학술대회논문집
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    • 2003.12a
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    • pp.215-221
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    • 2003
  • A series of experiments were conducted to study the effectiveness of the extinction of a liquid pool fire with two different water atomizing nozzles. Fire source is small-scale circular stainless steel pan of 120mm in diameter with the fuels of hexane and ethanol. K-type thermocouples were used to measure the flame and fuel temperature along the pool centerline and under fuel surface. A digital camera was used to visualize the process of the fire suppression. The experimental results show that water mist droplet size is $115{\sim}180{\mu}m$ with nozzle A and $130{\sim}190{\mu}m$ with nozzle B. The extinguishing time of pool fire was reduced with the increase of pressure. When water droplets are small, they do not reach the flame base since they may be deflected or evaporated by the fire plume. However, influence of flow rate is more important than droplet size on fire extinction. Among the fire extinction mechanisms, drop of flame temperature is superior to suffocation of O2 concentration.

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The Effect of Bangpungtongsungsan on Allergic Rhinitis Of Obese Mouse Fed High Fat Diet. (고지방식이로 비만을 유발한 마우스의 알레르기 비염에 대한 방풍통성산(防風通聖散)의 효과)

  • Kim, Dong-Hyun;Hong, Seung-Ug
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.29 no.1
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    • pp.1-15
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    • 2016
  • Objective : For various reasons, Obesity & Rhinitis are constantly rising. So Interest of treatment has been expanding. We want to verify The Chungyeol (fire extinguishing) Lisup (Draining) effect of Bangpungtongsungsan on obese model of allergy rhinitis.Material and Methods : BALB/c mouse were divided four groups: control(CON), allergic induction(ARE), Bangpungtongsungsan extract administration(BTT), Bangpungtongsungsan double concentration extract administration (BT2T). Every group except control group were caused allergic rhinitis by Ovalbumin. BTT & BT2T were orally administered the Bangpungtongsungsan for 21days. Since then we observed the liver tissue cell and the nasal mucous membrane.Results : In comparison with ARE, experimental groups show relief of the nasal mucous membrane damage(secretion of mucus decrease, Itching decrease), Th2 eruption control(IL-4 decline), effect of anti-inflamatory(reducing TNF-α creation, decreasing of iNOS through NF-κB activation-inhibition). In addition, experimental groups show a loss in weight, diminished accumulation of fat. (decreasing within liver tissue, reducing TNF-α creation) BT2T is more effective to BTT.Conclusion : Bangpungtongsungsan treat obese model on allergy rhinitis thereby control fat augmentation, relieving inflammation.

Reduction of the Electric Field Concentration at the Triple Junction of the Vacuum Interrupter by Using the Application of Functionally Graded Material (기능성 경사 재료의 적용을 통한 진공 인터럽터의 삼중점 전계 완화)

  • Choi, Seung-Kil;Gu, Chi-Wuk;Ju, Heung-Jin
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.10
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    • pp.630-635
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    • 2015
  • A vacuum Interrupter (VI), a core part that composes the breaking part of medium-voltage vacuum circuit breaker (VCB), has the excellent insulation performance and arc-extinguishing capability. $SF_6$ gas had been used for the external insulation of VIs since the dielectric strength of $SF_6$ gas is superior to that of other insulation gases. However, because of environmental problems related with global warming, a solid-insulated technology was recently researched. The functionally graded material (FGM), as changing spatially the distribution of the relative permittivity inside an insulator, can reduce the electric field stress at the specific region. Especially, the external insulation performance of the VI with the molded FGM insulator is greatly improved as compared with that of the existing VI or the VI with a new external shield. In this paper, the effectiveness of this FGM insulator is verified by the numerical simulation.