• Title/Summary/Keyword: Air-Assist Spray

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Enhancement of HF Gas Removal Efficiency of a Scrubber in Semiconductor Manufacturing Process by using ANCOVA Technique (ANCOVA를 이용한 반도체공정 스크러버 HF 가스 제거 개선)

  • Kim, S.J.;Lee, M.;Xu, J.;Lim, S.;Lee, H.;Koo, J.
    • Journal of ILASS-Korea
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    • v.18 no.2
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    • pp.81-86
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    • 2013
  • To comply with the regulation of the reinforcing Clean Air Conservation Act, it is necessary for the semiconductor manufacturers to develop effective low-concentration acid gas abatement system to treat the flue gas. The low-concentration acid gas was found to be harder to deal with than the high-concentration one. In this study, the effect of various potential treatments such as air-assist nozzle spraying, magnetizing the scrubbing water, and adding surfactants to spraying and scrubbing water were investigate through the application of the statistical ANCOVA method, which was proved to be very useful tool when the inlet concentration of acid gas could not be controlled precisely and it affected the removal efficiency of the abatement system.

Design of Roll-over Protection Structure for an Orchard Sprayer (과수용 방제기 전도 방지 구조물의 설계)

  • Kang, Tae-Gyoung;Lee, Chai-Sik;Jun, Hyeon-Jong;Choi, Duck-Kyu;Park, Suk-Ho;Kim, Hyeok-Ju;Kang, Tae-Hwan
    • Journal of Biosystems Engineering
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    • v.36 no.6
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    • pp.407-415
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    • 2011
  • Damage to agricultural production caused by insects and diseases affects farming yields. The orchard sprayer is mainly used in the country to protect the fruit in a large area, with less effort and at minimum cost. The excellent performance of the air blast spray increases the fruit protection. Chemical application in orchards has been accomplished by the orchard sprayers with air assist nozzles and a axial fan in Korea. However, the orchard sprayers without ROPS resulted in severe injury or death when operators drive the sprayers improperly on hilly orchard or farming road. This study was to develop a ROPS for the orchard sprayers improving farmer's safety. In this study, the accident case was used in analysing the design and building TOP structure of the orchard sprayer. The maximum impact, body torsion frame structures including the driver's protection are also analysed for adherence to safety regulations. The ROPS safety regulations according to the strength test results were established.

Effect of Atomization Characteristics of Twin Fluid Nozzle on Urea Pyrolysis (이유체 노즐 미립화 특성이 요소 열분해에 미치는 영향)

  • Ku, Kun Woo;Chung, Kyung Yul;Yoon, Hyun Jin;Seok, Ji Kwon;Hong, Jung Goo
    • Journal of ILASS-Korea
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    • v.20 no.3
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    • pp.162-167
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    • 2015
  • Recently, there has been rising interest in applying urea-SCR systems to large marine diesel engines because the International Maritime Organization (IMO) has decided to enforce NOx reduction regulations. Generally, in the case of urea-SCR of the marine diesel engine, a type of twin fluid atomizer has been using for injection of the urea solution. This study conducted to investigate an effect of the atomization of external-mixing twin fluid nozzle on the conversion efficiency of reductant. The lab-scaled experiment device was installed to mimic the urea-SCR system of the marine diesel engine for this study. In a low temperature inflow gas condition which is similar with the exhaust temperature of large marine diesel engine, this study found that the conversion efficiency of reductant of when relative big size urea solution droplets are injected into exhaust gas stream can be larger than that of when small size urea solution droplets are injected. According to results of this study, the reason was associated with decrease of reaction rate constant caused from temperature drop of inflow gas by assist air of twin fluid atomizer.

Automatic Layer-by-layer Dipping System for Functional Thin Film Coatings (다층박막적층법 적용 기능성 박막 코팅을 위한 자동화 시스템)

  • Jang, Wonjun;Kim, Young Seok;Park, Yong Tae
    • Composites Research
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    • v.32 no.6
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    • pp.314-318
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    • 2019
  • A simple and very flexible automatic dipping machine was constructed for producing functional multilayer films on wide substrates via the layer-by-layer (LbL) assembly technique. The proposed machine exhibits several features that allow a fully automated coating operation, such as various depositing recipes, control of the dipping depth and time, operating speed, and rinsing flow, air-assist drying nozzles, and an operation display. The machine uniformly dips a substrate into aqueous mixtures containing complementary (e.g., oppositely charged, capable of hydrogen bonding, or capable of covalent bonding) species. Between the dipping of each species, the sample is spray cleaned with deionized water and blow-dried with air. The dipping, rinsing, and drying areas and times are adjustable by a computer program. Graphene-based thin films up to ten-bilayers were prepared and characterized. This film exhibits the highly filled multilayer structures and low thermal resistance, indicating that the robotic dipping system is simple to produce functional thin film coatings with a variety of different layers.

Policy Direction for Fire Products Life Expectancy Legislation (소방용품 내용연수 제도화 정책방안)

  • Baek, Chang Sun;Park, In-Seon
    • Fire Science and Engineering
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    • v.30 no.1
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    • pp.111-120
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    • 2016
  • This study is intended to provide legislative direction for fire products life expectancy. Domestic and international laws relating to fire products life expectancy have been reviewed, and the results of a Fire Safety Manager Consciousness (FSMC) survey were analyzed. The FSMC survey has been designed in order to assist with the establishment of appropriate fire safety policy. A questionnaire survey was conducted with 660 fire safety administrators from 17 municipal and provincial districts, with the intention of gaining expertise on the extension of life-span for 32 fire products. The survey also asked for candidates opinions on future policy direction. Based on the survey results and the review of policies within other nations, we have devised a set of policy issues with the intention of extending the life-span of fire-safety items. The survey result revealed that 79.3% of Fire Safety Managers (FSMs) concurred with the establishment of legislation regarding the maintenance and correct care of fire-safety products. Overall, over 30% of FSMs were in favor of regulations regarding Ddry chemical fire extinguishers (77.3%), fire detectors (44.6%), fire hoses (44.4%), gaseous agent fire extinguisher (40.6%), automatic descending life lines (36.2%), exit lights (35.9%), air respirators (35.9%), extinguishing systems for residential cooking facilities (33.9%), automatic spray-type extinguishing units (33.9%), emergency lights (31.2%), and gas leakage detectors (30.7%). Especially, among these, dry chemical fire extinguishers (60.0%), detectors (20.0%), and fire hose (18.8%) were identified as the fire products primarily in need of maintenance legislation. The general consensus is that fire products older than 10 years need to be replaced. Based on the survey results, there was general agreement that fire product life expectancy is in need of legislation. This study recommends the introduction of fire product life expectancy legislation in phases.