• 제목/요약/키워드: spraying method

검색결과 387건 처리시간 0.039초

미세입자 분사가공 시 표면 조건 변화에 따른 가공 표면 형상 분석 (Analysis of Machined Surface Morphology According to Changes of Surface Condition in Micro Particle Blasting)

  • 최성윤;황철웅;권대규
    • 한국기계가공학회지
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    • 제17권5호
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    • pp.70-75
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    • 2018
  • This study analyzes the change of Al 6061-T6 specimen surface shape when undergoing microparticle spraying and analyzes the influence of factors on the experiment. Fine particle spraying is applied to the specimen and the surface shape of the processed surface is measured through a surface shape measuring device. The measured data was analyzed by the ANOVA method to investigate the effect of factors such as particle, nozzle diameter, pressure, injection height, and injection time on the injection depth and injection diameter.

정전분무모드에 관한 액적특성의 실험적 연구 (Experimental Study of Droplet Characteristics Related to Electrospray Mode)

  • 김지엽;이도현;조주형;홍정구
    • 한국분무공학회지
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    • 제27권1호
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    • pp.26-35
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    • 2022
  • Electrospray is a method of atomizing fluid using high voltage supply and capable of generating continuous flow and coherent size of droplets. Electrical system and properties of fluids has enabled electrospray to have various spray modes. However, its studies have been confined only in Cone jet, which is more stable and easier to manipulate droplets' size than other spraying modes. Therefore, it is necessary to investigate and compare other spraying modes based on experimental parameters and physical properties of fluids. This research paper identified nine different spray modes. It was found out that Sauter Mean Diameter (SMD) is proportional to flow rate of fluids and maximum difference among spray modes was 1.7 times. On the other hand, SMD standard deviation had low variations on specific flow rates of fluids. Pulsed jet mode recorded the largest SMD standard deviation, while Spindle recorded the lowest.

Zn-Al의 구성비율에 따른 금속용사 공법의 방식성능에 대한 실험적 연구 (Experimental Study of The Corrosion Protection Performance of The Metal Spraying Process in accordance with ratio of Zn-Al)

  • 김해;엄성현;정현규;이정배;김성수;안재우
    • 자원리싸이클링
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    • 제26권2호
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    • pp.56-65
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    • 2017
  • 본 연구는 금속용사 공법의 희생양극재료인 Zn, Al의 구성비율에 따른 방식성능에 관한 실험적 연구이다. 금속용사의 분사 방법으로는 Arc 금속용사 공법을 사용하였으며, Zn, Al의 구성비율 및 코팅 두께를 달리하여 시편을 제작하였다. 실험방법으로는 CASS 염수분무 실험에 준하여 실시하였으며 CASS 염수분무 시작일로부터 1, 3, 7, 15일 동안 실험체의 부식상태를 육안으로 관찰하였다. 본 연구결과 Al의 함량이 증가함에 따라 부식에 대한 방식성능이 증가함을 확인하였으며, 코팅두께 $80{\mu}m$ 이상을 확보하여야만 우수한 방식성능이 발현되는 것을 확인하였다. 또한 CASS 실험 후 금속용사 실험체의 단면 형상 관찰하기 위해 SEM 분석을 실시하였으며, 분석결과 Al의 함량이 증가할수록 금속용사 코팅층의 열화가 감소하는 것을 확인하였다.

양식업 종사자 포르말린 살포 작업에 대한 포름알데히드 노출평가 (Evaluation of Formaldehyde Exposure for Formalin Spraying Work of Fish Farm Workers)

  • 김은영;최성원;이성숙;손혜림;백진이;신재훈;김대호
    • 한국산업보건학회지
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    • 제33권4호
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    • pp.403-411
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    • 2023
  • Objectives: Formalin is used as an anthelmintic in farms where flounder are raised. In this study, we aim to identify formaldehyde exposure levels for aquaculture industry workers and provide basic data for managing formaldehyde exposure. Methods: Exposure levels of formaldehyde in the air, including formalin spraying operations, were assessed separately for personal and area samples. In addition, considering the formalin administration method, dermal exposure to the hands was estimated when administering the chemical, and dermal exposure to the legs during water tank work was estimated by collecting water in the water tank and evaluating the amount of formaldehyde remaining. Finally, the respiratory exposure level and the estimated dermal exposure level were added to derive the total exposure level and compared with the maximum allowable human dose. Results: As a result of the airborne evaluation, the formaldehyde concentration of the worker (1 person) who performed the formalin spraying and flounder sorting was 33.61 ppb, and the arithmetic mean of formaldehyde concentrations of the workers (3 people) who only performed the flounder sorting was 3.28 ppb (range: 2.25-4.89 ppb). In the case of dermal exposure, when spraying formalin once, the amount was estimated to be 0.33-2.62 mg when wearing protective gear and 3.27-26.12 mg when not wearing it. Conclusions: There was a difference in the formaldehyde exposure level of workers depending on their operation of handling formalin and whether or not protective gear was worn. In particular, because the level of formaldehyde exposure due to dermal exposure can be significant, there is a need to improve formalin administration methods in a way that avoids skin contact as much as possible.

주택단지 오수용 콘크리트 흄관의 부식속도 측정 사례 (A Case Study on Corrosion Rates of Concrete Sewer Pipes in Housing Sites)

  • 김영진
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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    • pp.550-553
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    • 2006
  • This study measured corrosion rates for checking and analysis of Hume pipes in the housing sites. According to the result, Concrete pipe is deteriorating for twenty years by hydrogen sulfide(H2S). Investigation method applied phenolphthalein method(depth of neutrality). Phenolphthalein method measured average depth from concrete surface to coloring point by red after spraying phenolphthalein solution. A result of investigation, Life span of Hume pipe in the housing site is investigated of twenty years.

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Systemic Fungicide Application for the Control of White Muscardine in Silkworm Rearing

  • Dutta, Monalisa;Nataraju, B.;Sharma, S.D.;Chandrasekharan, K.
    • International Journal of Industrial Entomology and Biomaterials
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    • 제6권1호
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    • pp.103-106
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    • 2003
  • Among silkworm diseases, white muscardine is the most virulent and contagious disease caused by Beauveria bassiana and common during winter and rainy seasons. The disease is managed at present by practicing the silkworm body and rearing seat disinfection to prevent the spread of white muscardine during silkworm rearing as the available methods do not cure the silkworms against white muscardine. The use of systemic fungicide was suggested recently to control white muscardine. The present study investigated the practicability of application aspect of systemic fungicide as spray, It is observed that 3 times feeding of systemic fungicide through mulberry leaf, fed immediately after third, fourth moult and on $4^{th}$ day of final instar as most effective in suppressing the multiplication of the fungus in silkworm. Spraying of the systemic fungicide on mulberry in the rearing house, air-dried and feeding was suggested as suitable application method. Alternately the spraying of the systemic fungicide on mulberry in mulberry garden 6 hrs prior to feeding was also suggested as a method for the control of white muscardine in silkworm rearing.

질산염 전구체 원료로 분무 열분해 방법에 의한 YBCO 박막 증착 (Deposition of YBCO Thin Film by Aerosol Assisted Spray Pyrolysis Method using Nitrate Precursors)

  • 김병주;홍석관;김재근;이종범;이희균;홍계원
    • Progress in Superconductivity
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    • 제12권1호
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    • pp.68-73
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    • 2010
  • Y123 films have been deposited on $LaAlO_3$ (100) single-crystal and IBAD substrates by spray pyrolysis method using nitrate precursors. Ultrasonic atomization was adopted to decrease the droplet size, spraying angle and its moving velocity toward substrate for introducing the preheating tube furnace in appropriate location. A small preheating tube furnace was installed between spraying nozzle and substrate for fast drying and enhanced decomposition of precursors. C-axis oriented films were obtained on both LAO and IBAD substrates at deposition temperature of around $710{\sim}750^{\circ}C$ and working pressures of 10~15 torr. Thick c-axis epitaxial film with the thickness of $0.3{\sim}0.6\;{\mu}m$ was obtained on LAO single-crystal by 10 min deposition. But the XRD results of the film deposited on IBAD template at same deposition condition showed that the buffer layers of the IBAD metal substrate was affected by long residence of metal substrate at high temperature for YBCO deposition.