• Title/Summary/Keyword: 흄

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Development of an Automatic Face Velocity Controller for a Fume Hood System (흄후드 시스템의 면 풍속 자동 제어기 개발)

  • Kim, Hogeol;Jeong, Kyuwon
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.2
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    • pp.304-309
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    • 2013
  • In chemical, medical or biology laboratories Fume Hoods are basic facilities which can protect researchers from dangerous gas as blowing the contaminated air outside. After the air inside the laboratory room is sucked into the hume hood, then, it is blew out by a fan rotated by an AC induction motor. In addition, a damper controls the inside opening of a duct, which the air flows through. The face velocity, air velocity through the front door, have to be kept constant as the set value even though the opening of the door is varied. However, conventional fume hood used to be operated by operator's manual switches. So that, in this paper an automatic control system is developed which controls the face velocity by adjusting the rotating speed of the blow motor and the opening of the damper. Experiments show that this developed system can be used at such laboratories.

Effects of Heavy Metal Fumes from Welding Fume Generating System on the Micronucleus Frequencies in Tradescantia (용접흄 발생기에서 발생된 중금속 흄이 자주달개비의 미세핵생성률에 미치는 영향)

  • 신해식;김진규;유일재;성재혁;이재환;이진홍;이대운
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.11a
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    • pp.461-462
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    • 2003
  • 산업의 발달과 함께 자연의 자정능력 한계를 넘어선 오염은 인간의 생존을 위협하는 심각한 사회문제로 대두되기에 이르렀다. 지금까지 대기오염에 대한 관심은 주로 실외대기, 즉 건물의 바깥쪽에 있는 대기오염에 편중되어 있었다. 대도시 및 중ㆍ소 공업 도시 등 대기오염이 문제되는 지역에서의 하루 생활은 하루 24시간 중 80%이상을 실내 공간에서 생활하고 있어 다양한 직업을 가진 현대인은 개인에 따라 다소 차이가 있지만 대기오염의 영향보다는 하루 중 많은 시간을 보내는 실내오염의 영향을 더 많이 받는다. (중략)

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Flow and Structural Analysis at Welding Fume of Automatic Gantry Robot - CFD/CAE and Automatic Convergence Study - (자동 겐트리 로봇의 용접 흄 유동 및 구조해석 - CFD/CAE 및 자동화 융합 연구 -)

  • Jang, Sung-Chul
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.11 no.6
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    • pp.158-163
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    • 2012
  • This study investigates numerical analysis for robot welder fume flow and gantry structure. The solvers are STAR-CCM+ and ANSYS workbench used on flow and structural analysis. The results show that fume is diffused in factory when the welding fume is remove at dust collector. But dust collector intercepts the fume diffusion into workroom by removing most of welding fume. Structure analysis result shows that the reinforcement rod is evaluated to main the safety by supporting sufficient structure.

A Study on Strength and Chloride Resistance of Concrete Using the Metakaolin (메타카올린 사용에 따른 콘크리트의 강도 및 염화물 저항성)

  • Kim, Myung-Yu;Yang, Eun-Ik;Yang, Joo-Kyoung;Park, Hae-Guun;Chun, Sang-Eun;Lee, Myeong-Sub
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.521-524
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    • 2008
  • The requirement for durability of concrete is increasing recently as a high-rise concrete structure is built. For this reason, the concern about high performance concrete is being high. Recently, metakaoline to be profitable in economical aspect as well as to have strength and durability of level similar to silica fume is evaluated highly as new admixture. In this study, the workability, the strength, the chloride resistance and the air-void structure more than 50${\mu}m$ are evaluated by comparing both metakaolin and silica fume. According to the results, when the metakaoline is compared with silica fume in properties of fresh concrete, it seems to the similar level of properties. Metakaoline concrete showed the highest value in the strength property. And, it is showed that replacement of the metakaoline more than 10% is superior than both silica fume and OPC in long and short-term chloride resistance. In conclusion, replacement of the metakaoline more than 10% is the most excellent performance in terms of strength and chloride resistance

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Strength Property of Ternary System Non-Cement Matrix according to the Curing Method (3성분계 무시멘트 경화체의 양생방법에 따른 강도특성)

  • Lee, Jin-Woo;Lee, Sang-Soo
    • The Journal of the Korea Contents Association
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    • v.14 no.4
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    • pp.389-396
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    • 2014
  • This study was conducted as the basic research for the replacement of Blast Furnace Slag, Red Mud, Silica Fume, etc., with cement as a solution to the problems arising from the global warming caused by the generation of $CO_2$, and conducted the experimental review to examine the feasibility of matrix having properties identical to those of cement by using the Blast Furnace slag, Red mud, Silica fume, and alkali-activator. For this, by using the the inorganic binder, such as Blast Furnace Slag, Red Mud, Silica Fume, etc., and NaOH, $Na_2SiO_3$ and others as the cement substitute material, the strength characteristic according to the mixture time variation was performed in the tentative experiment. Based on the preceding experiment, this study performed the experiment to analyze the strength properties of hardener through the curing by air-dry temperature, curing by temperature in water, coating curing, and Korean paper curing. For the water curing at $80^{\circ}C$, the compressive strength and flexural strength were found to be the most excellent at the age of the 28th day, and furthermore, it was found that the non-cement hardener could be made, which is considered to affect the production of eco-friendly concrete.

Health Risk Factors and Ventilation Improvements in Welding Operation at Large-sized Casting Process (대형 주물공정 용접작업장의 건강 위해인자 및 환기 개선)

  • Jung, Jong Hyeon;Jung, Yu Jin;Lee, Sang Man;Lee, Jung Hee;Shon, Byung Hyun;Lim, Hyun Sul
    • Clean Technology
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    • v.20 no.2
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    • pp.171-178
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    • 2014
  • In this study we have examined the health risk factors and analyzing data of laborers working at the welding operation at large-sized casting process. In order to improve the working environment of workplace, an effective ventilation method was proposed after performing CFD (computational fluid dynamics) modeling and measurement of pollutants. As a result of examining the health risk factors of workers, oxidized steel dust is the main pollution source in the company A, welding fume in the companies B and C, and welding fume and oxidized steel dust in the company D. The fume concentration in the workers' breathing zone was $0.05{\sim}4.37mg/m^3$, and the fume concentration in the indoor air at the welding process was $0.13{\sim}7.54mg/m^3$. From a result of CFD, a local exhaust with an exhaust duct adjacent to welding point was found to be most effective in case of the exhaust process. In case of air supply, we found that a desired location of air supply fan would be at the end of the opening. If a standardizing the ventilation system for tunnel-type semi-enclosed space at a large-sized casting process is introduced in welding work places in the future, it would be more effective to protect the health of welding workers working at the casting industry and shipbuilding industry and improve the work environment.