• 한국산업보건학회지
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• 제3권1호
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• pp.91-98
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• 1993

This study was carried out to investigate characteristic of vinyl chloride emissioned from poly vinyl chloride extrusion process and to evaluate the efficiency of local exhaust ventilation system. Before local ventilation facility was constructed in poly vinyl chloride extrusion process, the average worker exposure to vinyl chloride was 3.15 ppm, which exceeded Threshold Limit Value of American Conference of Gorvernmental Industrial Hygienists (ACGIH-TLV), 1 ppm. lt is possible that vinyl chloride residues in the poly vinyl chloride resin was released or degased due to extrusion heat. The larger the width of vinyl tube become, the higher worker exposure to vinyl chloride was. It is estimated that vinyl chloride from vinyl chloride resin increased as amount of poly vinyl chloride resin extruded in the extrusion process increased. Canopy hood was an appropriate type for poly vinyl chloride resin extrusion process. This local exhaust ventilation has fan static pressure of 7.65 inch wg($190mmH_2O$, total volumetric flowlate of 4,796 CFM ($135.8m^3$/min) and fan power requirement of 12 hp (8.952 Kw). After this local exhaust ventilation was constructed there, the average concentration of worker exposure to vinyl chloride was reduced to be 0.46 ppm, which was below the Threshold Limit Value, 1 ppm. Also, the removal efficiency rate of vinyl chloride attained by local exhaust ventilation was 85.3%. It was a statistically significant (p<0.01).

• 한국기계가공학회지
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• 제16권1호
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• pp.17-23
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• 2017

This study is about the development and revision of a blower design for a ventilation system. In this study, to describe the flow in the 4000CMM grade blower, 3-dimensional steady-state turbulence was assumed to govern the flow equation. The flow field with velocity distribution according to the elbow duct of the ventilation system is also compared. Finally, vibration was observed in the blower at the installation to ventilation system. The cause was due to a problem in the manufacturing process of the airfoil type impeller.

• 설비공학논문집
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• 제21권10호
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• pp.545-552
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• 2009

It is common to design the duct branches where to supply the required air flow for individual room in residential apartment house. And TAB process is applied to control the designed air volume with adjusting volume dampers and/or supply diffusers after fully installing the ventilation system. This process has been resulted increasing the initial cost for the residential ventilation system because of man-hour and accessories such as volume control damper or diffuser. However it is difficult to adjust the air volume adequately in small air duct branches in residential ventilation system. The purpose of this study is to figure out the performance of Multidrop chamber coupling system for the residential ventilation system.

• 한국산학기술학회논문지
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• 제10권3호
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• pp.463-469
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• 2009

시멘트 포장공정에서 발생하는 비산분진을 효율적으로 제거하기 위해 3가지 환기방식(국소배기시스템, 정전식스크러버시스템, 국소급기시스템)을 도입하고 풍량을 변화시키며 총 9가지의 조건에서 실험을 수행하였다. 분진의 농도는 시멘트분진 입자분포 특성을 고려하여 PM2.5, PM10, TSP로 구분하여 측정하였다. 3가지 환기방식에 대한 집진효율을 분석한 결과, 기존의 국소배기시스템과 정전식스크러버시스템이 같이 사용되는 경우 가장 효율적인 것으로 나타났다. 또한 정정식스크러버시스템의 풍량 증가에 따른 입자의 질량농도감소율이 큰 차이가 없는 것을 확인할 수 있었고 이로부터 정정식스크러버시스템을 $2,700m^3/h$ 풍량으로 운전하는 것이 에너지절약 관점에서 효율적인 것이라고 판단되었다. 각 환기방식별 환기성능을 국소배기시스템의 풍량으로 환산한 결과, 대체시스템(정전식스크러버시스템, 국소급기시스템)분진제거성능이 우수한 젓으로 나타났고 정전식스크러버시스템이 국소급기시스템보다 상당히 효율적인 것으로 나타났다. 따라서 기존의 국소배기시스템파 정전식스크러버시스템을 동시에 가동한다면 국소배기시스템의 풍량만을 증가시키는 경우에 비해 반송동력을 줄일 수 있어 분진제거와 에너지절감측면에서 훨씬 효율적이라는 것을 알 수 있었다.

• 펄프종이기술
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• 제33권1호
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• pp.64-72
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• 2001

The cigarette ventilation affects not only the amount of tar and nicotine delivery by a cigarette, but also the composition of the smoke. Therefore, it is important to stabilize of variability in cigarette ventilation that would be affected by changes in cigarette components. This work was conducted to determine the major factors that influence the cigarette ventilation and also to provide fundamental informations for improving the uniformity of cigarette performances. To evaluate the effect of cigarette ventilation as a dependant variable, the three independent factors were the air permeability of plugwrap, tipping paper and the filter pressure drop. We determined the effect of paper permeability on ventilation variability and the optimum condition in combinations of independent factors. The mean of cigarette ventilation was increased as plugwrap permeability increases, particularly at 26,000 CU. However, it was exhibited that standard deviation and coefficient of variation of the cigarette ventilation were decreased with increasing plugwrap permeability. At the 600 CU and 1,200 CU of tipping paper permeability, process capability index (Cp) of the cigarette ventilation increased as plugwrap permeability increases. Following the optimum condition of cigarette ventilation induced by fitted regression equation, one was to optimize 50% ventilation level is by combination with plugwrap permeability of 16,000 CU, tipping paper permeability of 810 CU, filter pressure drop of 319 mm$H_2O$, respectively.

• 설비공학논문집
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• 제27권8호
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• pp.440-447
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• 2015

In the shipbuilding process, the confined work spaces of the ship are formed continuously; the ventilation method can therefore be limited to dilution ventilation due to the complex structure and limited opening of the confined space. Also, it is difficult to evaluate air-quality using measurement and an adequate ventilation method. CFD simulation methods are typically used in analyzing ventilation efficiency in these cases. In this study, a method is suggested to analyze the air quality of the complex enclosures in shipbuilding using CFD. Especially, among the conventional indices, the ventilation efficiency scales or indices, the supply air contribution (SVE4), and the age of the air (SVE3) (fit for the confined and complex enclosure) were applied.

• 한국공작기계학회논문집
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• 제14권5호
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• pp.87-92
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• 2005

In this study, an automation assembly jig for the automation assembly process for the ventilation grille that is used in the interior of a car Is developed. As the method that can do the automation assembly for the ventilation grille, a simple jig and air cylinder have been applied. And a solenoid valve, a filter regulator, and on-off switch have been used in controlling the system. Moreover, the timer is attached to the equipment so that a worker may control the assembly time, as fitting the quantity on demand of production. Actually with executing the assembly test productivity and performance of assembly have been verified. In case of the automation assembly work for a ventilation grille is compared to the manual work. The optimum working speed has been identified to make the process twice or three times better.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
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• pp.77-82
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• 2000

In this study, an automation assembly jig for the automation assembly process for the ventilation grille that is used in the interior of a car is developed. As the method that can do the automation assembly for the ventilation grille, a simple jig and air cylinder have been applied. And a solenoid valve, a filter regulator, and on-off switch have been used in controlling the system. Moreover, the timer is attached to the equipment so that a worker may control the assembly time, as fitting the quantity on demand of production. Actually with executing the assembly test productivity and performance of assembly have been verified. In case of the automation assembly work for a ventilation grille is compared to the manual work. The optimum working speed has been identified to make the process twice or three times better.

• 한국기계가공학회지
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• 제14권5호
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• pp.96-101
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• 2015

This study regards distributions of flow in the ventilation system used in the kitchen hood in a ship. In this study, for describing the flow in the ventilation system, three-dimensional steady-state turbulence was assumed for the governing equation. When the plume was formed, three gases, CO, CO2, and HCL, in the flow field of the hood were considered as the plume, and it was assumed that the sum of concentrations of the gases was 100%. As a result, it could be confirmed that the plume was smoothly discharged when the flow rate of the supply was ten times lower than that of the exhaust.

• 한국기계가공학회지
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• 제16권1호
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• pp.30-35
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• 2017

This study is about distributions of flow in a ventilation system used in a louver for marine. In this study, to describe the flow in the ventilation opening louver, 3-dimensional steady-state turbulence was assumed to govern the equation. The flow field with pressure distribution according to the inlet velocity at the louver types is also compared. Flow analysis was performed for the louver numerical analysis on two types. The numerical analysis results in the louver blade indicated increased flow resistance at type-1.