• Title/Summary/Keyword: Compressed air-breathing

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A Study on the Effect of Compressed Air Using Air-breathing Upon Human (공기호흡기용 압축공기가 인체에 미치는 영향에 대한 연구)

  • 이창우;이용재;현성호;성재만;최돈묵;윤명오
    • Fire Science and Engineering
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    • v.18 no.3
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    • pp.95-102
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    • 2004
  • This paper has analyzed compressed air-breathing that fire fighters use in Korea. And the local and the foreign standards for compressed air have been compared. Through the survey, it has been found that over 75% of all the respondents have ever had simple abnormal symptoms after wearing air respirators, and among the abnormal symptoms, nausea and headache are most frequent. Maintenance and exchange of compressor filters were poor and it can be another cause of abnormal symptom of fire fighters. Korea does'nt have any particular standards for compressed air-breathing, and the compressed air that is used by fire fighters is not different from air for industrial use. However, advanced countries like Europe, Canada and America, they have special standards for compressed air-breathing that fire fighters use. Through the analysis of components of the compressed air used in Korea, it has been found that all the samples have more water than the international standards.

A Study on the Fracture Characteristics of Ceramics Using Compressed Shock Wave (압축 충격파를 이용한 세라믹의 파괴특성에 관한 연구)

  • Hwang, Kwon-Tae;Kim, Jae-Hoon;Lee, Young-Shin;Park, Jong-Ho;Song, Kee-Hyeuk;Yoon, Su-Jin
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.338-343
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    • 2008
  • Fracture characteristics of plates and dome shapes for machinable glass ceramics using compressed shock wave. Machinable glass ceramics have been considered as a promising candidate material for the dome port cover of air breathing engine. This part of the air breathing engine has an important role separating solid and liquid fuel, and needs the frangible characteristics whereby the fracture of a part should not affect the internal components of combustion. The objective of this study are to evaluate the fracture pressure and phenomena of separated membrane using a shock tunnel. The experimental apparatus consists of driver, a driven section and a dump tank. The used material is machinable glass ceramic from Corning company. Specimens are used 3, 4.5 and 6mm thickness with plates and dome shapes. It is expected that the results obtained from this study can be used in the basic data for the dome port cover design of an air breathing engine.

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Analyses of Scenarios Based on a Leakage of Highly Compressed Air and Fire Anticipated in CAES (Compressed Air Energy Storage) Facility (압축공기에너지저장 시설에서 발생 가능한 압축공기 유출 및 화재 시나리오 분석)

  • Yoon, Yong-Kyun;Ju, Eun-Hye
    • Tunnel and Underground Space
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    • v.25 no.6
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    • pp.568-576
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    • 2015
  • In this study, scenarios based on the leakage of highly compressed air and fire occurrence turned out to be high risks in an operation stage of CAES facility were constructed and estimated. By combining Bernoulli equation with momentum equation, an expression to calculate an impact force of a jet flow of compressed air was derived. An impact force was found to be proportional to the square of diameter of fracture and the pressure of compressed air. Four types of fire scenarios were composed to evaluate an effects that seasonal change and location of fire source have on the spread behavior of smoke. Smoke from the fire ignited in the vicinity of CAES opening descended more quickly below the limit line of breathing than one from the fire occurred 10 m away from CAES opening, which is expected to occur due to a propagation of wave front of smoke. It was shown that a rate of smoke spread of the winter fire is faster than one of the summer fire and smoke from the winter fire spreads farther than one of the summer fire, which are dependent on the direction of air flow into access opening. Evacuation simulation indicated that the required safe evacuation time(RSET) of the summer and winter fires are 262, 670 s each.

A Study on the Actual Condition for Air Respirators Using Air-breathing (공기호흡기용 압축공기 시스템에 대한 실태 연구)

  • Lee Chang-Woo;Lee Young-Jae;Hyun Seong-Ho;Seong Jae-Man;Song Yun-Suk;Choi Don-Muk;Yoon Myung-O
    • Fire Science and Engineering
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    • v.18 no.4
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    • pp.16-21
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    • 2004
  • This paper has investigated influences of pollutants in air-breathing on the respirators and it by year of disused air respirators that fire fighter is using in domestic cutting done air respirators after collection observed state of cylinder material through instrumental analysis, and cut open pipe to confirm pollution degree of pipe from cylinder of air respirators to airline mask and confirm pollution availability. The metal surface inside the air respirators was corroded by moisture included in the compressed air. The material generated by corrosion is white powder of less then 100㎛, which is analyzed as aluminum hydroxide corroded by moisture. This aluminum hydroxide powder may get into the lung while one breathes in, and it is easy to be attached to the lung so it will cause a serious influences to human health. This study suggests that Korea should set out the standards for components and composition of breathing air as soon as possible.