• Title/Summary/Keyword: air Guality

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A Study on Coating Deviation Effect by Air Knife Characteristics in CGL (연속용융도금라인에서 에어나이프 특성이 도금편차에 미치는 영향)

  • Bae, Y.H.;Ahn, D.S.;Lee, S.H.
    • Journal of the Korean Society for Precision Engineering
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    • v.10 no.3
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    • pp.57-68
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    • 1993
  • Air Wiping technique is widely used because of easy and efficient coating control in present CGL. Coaring weight is decided by nozzle header pressure, strip line speed and distance between strip and nozzle. Coating defects are results from unbalance of these factors and coating equipment calibration inaccuracy. Therefore, this study is mainly dealing with the cause of coating defects such as edge overcoating and coating deviation. The coptimum working condition is suggested by formulated coating model using collected working data. We developed two demension analysis program for air flow in nozzle and calculated dynamic pressure and air velocity with this program. The productivity and coating guality are improved by applying the result of this reserach.

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A Study on the using of the Ventilation System as the Method of Improvement of Air Quality in the Schools (학교건물의 공기질 개선을 위한 환기시스템 적용에 관한 연구)

  • Ahn, Chul-Lin;Kim, Jwa-Jin;Kum, Jong-Soo;Park, Hyo-Soon
    • Journal of the Korean Institute of Educational Facilities
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    • v.11 no.2
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    • pp.17-23
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    • 2004
  • The purpose of this study concerns the improvement of air quality in school classrooms. Polluted indoor air is improved by efficient ventilation systems. So it is important to measure the amount of ventilation needed in classrooms. First, the amount of natural ventilation were measured through a tracer gas method. And we have established a heat recovery ventilation system from 4 cases of airflow in classrooms, and we have measured the change of $CO_2$ density. According to air quality measurements in the classrooms, the density of $CO_2$ is well above environmental standards which are acceptable. When the amount of ventilated airflow increases, indoor air quality is improved. It is surveyed that the most suitable amount of external inducted air is 770 CMH to satisfy $CO_2$ less than 1,000 ppm in classrooms. For improvement of air quality in classrooms, we must consider a suitable ventilation plan and installation of ventilation systems when constructing school buildings.

Optimization of the Korean Packaged Meal (Dosirak) Production Facilities for Food Service Delivered Long Distance (원격지 단체급식을 위한 포장용 도시락 생산설비의 최적화 연구)

  • Park, Hyung-Woo;Koh, Ha-Young;Park, Noh-Hyun;Kang, Tong-Sam;Mo, Su-Mi
    • Journal of the Korean Society of Food Culture
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    • v.3 no.1
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    • pp.89-93
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    • 1988
  • Because the production facilities of the Korean convenient food companies are placed in one space, the final products could be easily contaminated. It is necessary that the work space should be devided into contaminated zone, semisanitary zone and sanitary zone. The layout of the preparation facilities are reconsidered. Requirements for equipment and the facilities criteria be complemented with the air clean unit, and chilling refrigerator for rapid chilling of boiled rice and the cooked dishes for the assurance of the microbiological guality of foods. The equipment and the work space of the model companies which have the area of $99m^2,\;200m^2\;and\;300m^2$ are properly placed and designed in accordance with the regulations of the food sanitation and the architecture. (Packaging Meal Production Facilities).

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