• 제목/요약/키워드: mist

검색결과 480건 처리시간 0.021초

Water Mist Fire Suppression for Raised Subfloor Spaces

  • Kim, Woon-Hyung;Kim, James A. Milke
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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    • pp.617-624
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    • 1997
  • Over 100 experiments have been conducted at the University of Maryland to evaluate the performance of a water mist fire suppression system for protection of an interstitial space below a raised subfloor. Experiments are conducted as part of an ongoing research effort to compare the fire suppression capabilities of various water mist system designs in a raised subfloor space. Water mist system design parameters considered in the investigation include means of actuation, concentration of water mist required for extinguishment of fires, and delivery mechanisms of water mist within close proximity to the fire. Delivery of the required concentration of water mist within close proximity to the fire is a principal factor governing the adequacy of water mist systems. Two sets of experiments have been conducted to document the performance of water mist system designs. One set is involved in documenting the concentration of water mist as a function of position within the space. The second set of experiments is concerned with the ability of water mist system designs to control fires in the space. One result of the research is the assessment of the ability of a water mist system to control fires at particular locations as a function of water mist density at that location.

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The Effects of Water Mist on the Compartment Fire

  • Ryou, Hong-Sun;Kim, Sung-Chan
    • International Journal of Air-Conditioning and Refrigeration
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    • 제12권1호
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    • pp.30-36
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    • 2004
  • The present study investigates the fire suppression characteristics using a water mist fire suppression system. Numerical simulations of fire suppression with water mist are performed with considering the interaction of fire plume and water spray. The predicted temperature fields of smoke layer are compared with those of measured data. Numerical results agree with the experimental results within $10^{\circ}C$ in the case without water mist. In the case of fire suppression with water mist, numerical results do not predict well for temperature field in the gradual cooling region after water mist injection. But the predicted results of initial fire suppression are in good agreement with those of measured data. The reason for the discrepancy between predicted and measured data is due to the poor combustion modeling during the injection of water mist. More elaborate models for numerical simulation are required for better predictions of the fire suppression characteristics using water mist.

초음파진동을 이용한 미세분무냉각 열전달에 관한 실험적 연구 (The Experimental Study on Mist Cooling Heat Transfer)

  • 김영찬
    • 한국분무공학회지
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    • 제15권4호
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    • pp.202-207
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    • 2010
  • Mist cooling is widely employed as a cooling technique of high temperature surfaces, and it has heat transfer characteristics similar to boiling heat transfer which has the convection, nucleate and film boiling regions. In the present study, mist cooling heat transfer was experimentally investigated for the mist flow impacting on the heated surfaces of mico-fins. The mist flow was generated by supersonic vibration. Experiments were conducted under the test conditions of droplet flow rate, $Q=6.02{\times}10^{-9}{\sim}3.47{\times}10^{-8}\;m^3/s$ and liquid temperature, $T_f=30{\sim}35^{\circ}C$. From the experimental results, it is found that an increase in the droplet flow rate improves mist cooling heat transfer in the both case of smooth surface and surfaces of micro-fins. Micro-fins surfaces enhance the mist cooling heat transfer. Besides, the experimental results show that an increase in the droplet flow rate decrease the heat transfer efficiency of mist cooling.

미세 물 분무 소화 성능에 관한 연구 (A study on the Water Mist Fire Suppression Performance)

  • 김봉환;김용판;문철진;홍철현;이형욱
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2002년도 춘계학술대회논문집
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    • pp.61-65
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    • 2002
  • The present study was numerically and experimentally performed to investigate the fire suppression performance of water mist spray subjected to thermal radiation in closed space. Downward-directed water mist sprays to interact with an under kerosine pool fire were investigated in test facility. The mass mean diameters of water mist droplet were measured by PMAS under various flow conditions. The developed water mist spray nozzle was satisfied to the criteria of NFPA 750, Class 1. The mechanism of the fire suppression by water mist was concluded to be cooling of the fire surface which lead to suppressed of fuel evaporation. It was proved that the water mist spray system under lower pressures could be applied to underground fire protection system.

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물분무에 의한 화재제어 특성에 관한 연구 (A Study on the Fire Suppression Characteristics Using a Water Mist)

  • 김성찬;유홍선
    • 설비공학논문집
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    • 제15권4호
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    • pp.261-267
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    • 2003
  • The present study investigates the fire suppression characteristics using a water mist fire suppression system. Numerical simulations of fire suppression with water mist are performed with considering the interaction of fire plume and water droplet, droplet evaporation, and combustion of pool fire. The predicted temperature fields of smoke layer are compared with that of measured data. Numerical results agree with the experimental results within 5$^{\circ}C$ in the case without water mist In the case of fire suppression with water mist, numerical results dose not predict well lot temperature field in the gradual cooling region after water mist injection. But the predicted results of initial fire suppression are in good agreement with that of measured data. The reason of the discrepancy between predicted and measured data is due to the variation of turning rate during the injection of water mist. The effect of burning rate on the fire suppression is left as future study.

용량센서를 적용한 오일증기검출기 거동 해석 (Analysis of Oil-Mist-Detector applied Capacitance Sensor)

  • 이길승;김태옥;김화영;안중환
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2006년도 춘계학술대회 논문집
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    • pp.279-280
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    • 2006
  • This paper analysised Oil-Mist-Detector applied Capacitance Sensor which protects Diesel engine & human from explosion by detecting density of oil mist distribution. Assuming that distance between oil mists is same, Capacitance sensor plates & all oil mists could be analogized to capacitors. From equivalent circuit of Oil-Mist-Detector, variation of Capacitance which is related to Oil Mist's diameter & density of oil mist distribution is obtainable.

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미세물분무 소화성능에 관한 연구 (A Study on the Performance of Water Mist Spray Fire Protection System)

  • 김봉환;김용판;문철진;홍철현;이형욱;최현호
    • 설비공학논문집
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    • 제15권7호
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    • pp.572-578
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    • 2003
  • The present study was numerically and experimentally performed to investigate the fire suppression performance of water mist spray subjected to thermal radiation in closed space. Downward-directed water mist sprays to interact with an under kerosine pool fire were investigated in test facility The mass mean diameters of water mist droplet were measured by PMAS under various flow conditions. The developed water mist spray nozzle was satisfied to the criteria of NFPA 750, Class 1. The mechanism of the fire suppression by water mist was attributed to the cooling of the fire surface which lead to suppressed of fuel evaporation. It was proved that the water mist spray system under lower pressures could be applied to underground fire protection system.

자동차 내부의 김서림 감지 및 제거를 위한 최적의 조건 (Optimal Conditions for Mist Sensing and Removal in Automobile)

  • 유도현
    • 전기학회논문지
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    • 제61권5호
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    • pp.763-769
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    • 2012
  • For mist sensing, temperature-humidity sensor is attached on six positions of front glass and rearview mirror in automobile. Bottom-left side of front glass is the best position where mist is sensing. For mist removal, air conditioner is turned on intensity 1, 3 and is set the temperature at 17[$^{\circ}C$], 25[$^{\circ}C$]. And heater is turned on intensity 1, 3 and is set the temperature at 25[$^{\circ}C$], 32[$^{\circ}C$]. The best condition which mist is removed is temperature at 17[$^{\circ}C$] and intensity 3 of air conditioner mode. At this condition, total average value of humidity output voltage difference is 0.561[V]. Also, air conditioner mode is effective than heater mode for mist sensing and removal.

CFD모델링을 통한 오일 미스트필터효율 향상 결정요소에 관한 연구 (Determining Factors to Enhanced Oil Mist Filter Efficiency Using CFD Modeling)

  • 신희재
    • 한국기계가공학회지
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    • 제20권10호
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    • pp.119-127
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    • 2021
  • Small drops in gas cause some problems for downstream equipments such as turbine, compressor and etc. In some cases, we are obliged to remove hazardous liquid mist from gas. In order to remove water or other liquids from the gas, there are some equipments like mesh mist eliminator and vane-plate mist eliminator. oil mist filter is a kind of liquid eliminator equipments used to remove the liquid with 1-10um droplet diameter from the gas. In this paper is determine the factors affecting the oil mist filter efficiency using CFD. length and angle of the filter were considered and the results and compare the results of the efficiency tests, showed error of less than 3%. optimum filter can remove more than 87.3% between 1 and 10um of oil mist.

탈색 시술 시 미스트 사용 여부에 따른 모발의 변화 (Hair Changes with the Use of Mist during Hair Bleaching)

  • 김은비;임순녀
    • 한국염색가공학회지
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    • 제30권4호
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    • pp.304-312
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    • 2018
  • This study reduced the number of hair bleachings and used a hair steamer machine to reduce hair damage during hair coloring. In addition, such treatment was given, focusing on the use of hair mist. When the $L^{\ast}a^{\ast}b^{\ast}$ values for bleached hair were measured using a spectrum colorimeter, the mist steamer-based hair revealed higher brightness. Hair damage was low when moisture contents were high after hair drying with the use of the mist steamer machine. The mist treatment-less hair showed more blurred cuticle boundaries than mist-treated hair. In other words, this confirms that cuticles are protected by the use of a mist steamer machine during hair bleaching. It appears that this could minimize hair loss and meet clients' aesthetic needs and satisfaction during color bleaching/coloring.