• Title/Summary/Keyword: Liquid fire

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[Retracted]Improving Performance of Foam Proportioner Utilizing Metering Venturi Type ([논문철회]미터링 벤츄리를 이용한 포소화약제 혼합장치의 성능개선)

  • Joo, Seung-Ho;Kong, Ha-Sung;Gong, Ye-Som
    • Fire Science and Engineering
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    • v.29 no.3
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    • pp.48-52
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    • 2015
  • In this study, we have evaluated whether the mixing ratio is proper by creating a mixing device for foam proportioner that mainly is employed in practice utilizing a metering venturi type. In case of the mixing ratio for 3%, water under pressure of 76 mm in diameter and the original liquid of a foam fire extinguishing agent of 31.75 mm in diameter have showed up the fluctuation rate just as much as 3.1~3.5% of the mixing ratio. Because water under pressure of 101.6 mm in diameter and the original liquid of a foam fire extinguishing agent of 38.1 mm in diameter have showed up 3.3~3.7% of the fluctuation rate, water under pressure of 101.6 mm in diameter and the original liquid of a foam fire extinguishing agent of 38.1 mm in diameter have satisfied 3.0~3.9% of performance criterion. And also, in case of the 6% of mixture rate, water under pressure of 76.2 mm in diameter and the original liquid of a foam fire extinguishing agent of 31.75 mm in diameter have showed up the fluctuation rate just as much as 6.4~6.8% of the mixing ratio. Because water under pressure of 101.6 mm in diameter and the original liquid of a foam fire extinguishing agent of 38.1 mm in diameter have showed up 6.0~6.8% of the fluctuation rate, water under pressure of 101.6 mm in diameter and the original liquid of a foam fire extinguishing agent of 38.1 mm in diameter have satisfied 6.0~7.0% of performance criterion.

Optical Properties for Smoke Particles of Fire Sources According to UL 268 (UL 268 화원에 의한 연기입자의 광학적 특성)

  • Jee, Seung-Wook;Lee, Jong-Hwa
    • Fire Science and Engineering
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    • v.28 no.2
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    • pp.9-13
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    • 2014
  • This paper is basic study for development of the photoelectric-type smoke detector that is able to distinguish fire source as well as fire detection. For this subject, Light source and sensor which is normally used for the conventional smoke detector are assembled for the optical chamber. Using 3 type of the test fires (the paper fire, the wood fire, the flammable liquid fire) this paper attempts to find optical properties of each fire. These 3 type of fire are used in the testing of smoke detector according to UL 268 standard. As the result, there are disambiguated between the paper fire and the wood fire in scattering and reason of extinction in the flammable liquid fire is different from that of the paper and the wood fire.

Extinguishment of Liquid Fuel Fire by Water Mist Containing Additives

  • Park, Jae-Man;Won, Jung-Il;Shin, Chang-Sub
    • International Journal of Safety
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    • v.4 no.2
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    • pp.24-29
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    • 2005
  • An experimental study was presented for extinguishing characteristics of liquid fuel fire by water mist($Dv_{0.99}{\leq}200{\mu}m$) containing potassium acetate and sodium acetate trihydrate. To evaluate the extinguishing performance of water mist containing additives, the evaporation characteristics of a water droplet on a heated surface was examined. The evaporation process was recorded by a charge-coupled-device camera. Also, small-scale extinguishing tests were conducted for n-heptane pool fire in ventilated space. During the experiments, flame temperatures were measured, and concentrations of oxygen and carbon monoxide were analyzed by a combustion gas analyzer. The average evaporation rate of water droplet containing additives was lower than that of pure water at a given surface temperature and decreased with the concentration increase due to the precipitation of salt in the liquid-film and change of surface tension. In case of using additives, the fire extinguishing times was shorter than that of pure water at a given discharge pressure and it was because the momentum of a water droplet containing additives was increased. And also dissociated metal atoms, potassium or sodium, were reacted as a scavenger of the major radical species OH, H which were generated for combustion process. Moreover, at a high pressure of 4 MPa, the fire was extinguished through blowing effect as well as primary extinguishing mechanisms.

A Study on the Measurement and Comparison(IEC 60079-32-2) of Flammable Liquid Conductivity (인화성 액체 도전율에 관한 측정 및 비교(IEC 60079-32-2) 연구)

  • Lee, Dong Hoon;Byeon, Junghwan
    • Journal of the Korean Society of Safety
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    • v.34 no.4
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    • pp.22-31
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    • 2019
  • The flammable liquid conductivity is an important factor in determining the generation of electrostatic in fire and explosion hazardous areas, so it is necessary to study the physical properties of flammable liquids. In particular, the relevant liquid conductivity in the process of handling flammable liquids in relation to the risk assessment and risk control in fire and explosion hazard areas, such as chemical plants, is classified as a main evaluation item according to the IEC standard, and it is necessary to have flammable liquid conductivity measuring devices and related data are required depending on the handling conditions of the material, such as temperature and mixing ratio for preventing the fire and explosion related to electrostatic. In addition, IEC 60079-32-2 [Explosive Atmospheres-Part 32-2 (Electrostatic hazards-Tests)] refers to the measuring device standard and the conductivity of a single substance. It was concluded that there is no measurement data according to the handling conditions such as mixing ratio of flammable liquid and temperature together with the use and measurement examples. We have developed the measurement reliability by improving the structure, material and measurement method of measuring device by referring to the IEC standard. We have developed a measurement device that is developed and manufactured by itself. The test results of flammable liquid conductivity measurement and the data of the NFPA 77 (Recommended Practice on Static Electricity) Annex B Table B.2 Static Electric Characteristic of Liquids were compared and verified by conducting the conductivity measurement of the flammable liquid handled in the fire and explosion hazardous place by using Measuring / Data Acquisition / Processing / PC Communication. It will contribute to the prevention of static electricity related disaster by taking preliminary measures for fire and explosion prevention by providing technical guidance for static electricity risk assessment and risk control through flammable liquid conductivity measurement experiment. In addition, based on the experimental results, it is possible to create a big data base by constructing electrostatic physical characteristic data of flammable liquids by process and material. Also, it is analyzed that it will contribute to the foundation composition for adding the specific information of conductivity of flammable liquid to the physical and chemical characteristics of MSDS.

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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Development of the Remote Control System for Liquid Rocket Propulsion System (액체로켓 추진개관 원격제어시스템 개발)

  • 이주열;김재문;김영수;홍일희
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2003.05a
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    • pp.207-210
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    • 2003
  • The purpose of this work is to introduce the Remote Control System for KSR-III Liquid Rocket Propulsion System. We developed the high reliable Fire control System that needed for long distance control. We carried out a real time remote control and measuring for KSR-III lust Liquid Propulsion Rocket in Korea using TCP/IP Ethernet network method and Fiber-optic communication method. Also HMI operation program developed guarantee confidential control, monitoring and analysis for Fire control operation.

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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.