• 한국산업보건학회지
• /
• 제33권3호
• /
• pp.280-283
• /
• 2023

Objectives: The purpose of this study was to examine the change in exposure concentration in the cleaning process after installing a local exhaust system. Methods: Dichloromethane measurement was conducted according to the KOSHA Guide (A-19-2019). Results: After the local exhaust device was installed, a total of three measurements were conducted, including temporary work environment measurements, and all of the measurements did not exceed the DCM exposure standard, but were more than 50% of the DCM Time Weighted Average((8-TWA) Conclusions: It is thought that the local ventilation system of a small business needs not only support for the initial installation cost, but also educational support for maintaining the performance of the local ventilation system and support for consumables (adsorbents, filters, etc.) that incur periodic costs.

• 터널과지하공간
• /
• 제13권3호
• /
• pp.235-243
• /
• 2003

최근 경향은 터널연장이 점점 장대화되고 있음을 보여주고 있으며, 또한 경제적인 이유로 고속도로 터널의 제트팬 종류 환기방식에 대한 적용이 점차 증대되고 있다. 차량엔진의 성능이 향상됨에 따라 최적 환기방식을 결정하는 중요한 요소인 소요환기량(Qreq)은 결과적으로 줄어들고 있다. 소요환기량 특성도(Qreq contour map)는 터널연장, 종단경사 그리고 소요환기량 사이의 관계를 나타내는 그래프이다. 그리고 제트팬 환기방식이 가능한 터널제원을 평가하기 위해서는 소요환기량의 변화를 이해하는 것이 중요하다. 그러므로 본 연구에서는 소요환기량 특성도를 이용하여 제트팬 환기방식의 가능 터널제원을 결정하는 그래프적 분석법에 관한 연구를 대상으로 하고 있다. 또한 국내 고속도로상의 지역별 교통량 구성비에 따른 분석도 연구대상으로 하고 있다.

• 설비공학논문집
• /
• 제22권12호
• /
• pp.867-872
• /
• 2010

Numerical analysis has been conducted to investigate the fluid flow and fume mixing ratio characteristics of scattering fume in a push-pull ventilation system and optimally improve the flow patterns of scattering fume in the existing ventilation system. This ventilation system has been simulated by using commercial CFD code. In the case of the existing system, although the air is sprayed from air-curtain to prevent the fume from being scattered in upper hood, the improved air supply hood can remove the fume from the wide area in the high pressure. It is verified that the deeper plating storage is more advantageous. Also, by installing the shied around the plating storage, the scattering of the fume to the atmosphere was prevented effectively by surrounding flux.

• 한국의류산업학회지
• /
• 제7권1호
• /
• pp.75-80
• /
• 2005

The purpose of this study was to investigate the effects of silt ventilation system on physiological responses. We measured rectal temperature, local skin temperature, clothing microclimate, blood pressure, heart rate, energy metabolism, body weight loss and subjective sensation during 70 minute, 50 min exercise period and 20 min rest period. The five women subjects randomly wore sportswear without slit ventilation system(NS sportswear) and sportswear with slit ventilation system(S sportswear) under the environmental condition of $25^{\circ}C$, 50%RH. The results of this study are as follows; Rectal temperature, mean skin temperature, clothing microclimate, blood pressure, heart rate, energy metabolism and body weight loss were significantly lower level in 'S sportswear'. In 'S sportswear', subjects replied less hot, less uncomfortable and less wet. Slit ventilation system can be used for bellow effect which is meaningful device of convection during exercise. We could find out that 'S sportswear' has advantage in physiological function.

• 설비공학논문집
• /
• 제27권2호
• /
• pp.57-62
• /
• 2015

The objective of the present study is to identify the ventilation problems and to suggest the optimal ventilation system to save energy and to improve IAQ in the computer rooms, which annually performs the cooling operation by the server with the highly thermal load. Numerical results on the temperature and local mean age are presented along with some of the discharge velocities. Results show many interesting aspects of airflow patterns affecting the ventilation performances, according to the discharge velocity of the supply diffuser installed in the bottom surfaces between the servers. As the results, 2.5 m/s of the optimal discharge velocity is needed in order to improve the ventilation performance.

• 설비공학논문집
• /
• 제10권5호
• /
• pp.610-618
• /
• 1998

In this study, a tracer gas technique was used to measure ventilation effectiveness in a thermal environmental chamber simulating an under-floor air conditioning system. A tracer gas of $SF_6$ was injected in a supply duct using step-up and step-down methods. Local mean ages and room mean ages were calculated from the measured concentrations under isothermal and cooling conditions with and without diffusers. Ventilation effectiveness is found to be higher in cooling ventilation operations than in isothermal operations. Results also show that ventilation effectiveness is not significantly affected by a diffuser.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
• /
• 제2권1호
• /
• pp.49-56
• /
• 1998

This study identified the fumes produced from the cooking of the seasoned meats containing various condiments such as garlic, onion, pepper, soy sauce, and sesame oil. Concentrations, at the breathing zone of the cook, of volatile organic compounds (VOCs) and aldehydes included in the cooking fumes of seasoned meats were identified. Many chloro and fluoro-aliphatic hydrocarbons, aromatic hydrocarbons, ketones, and aldehydes, which could be carcinogen suspecting chemicals, were producing from the cooking fumes of the seasoned meats. This study also identified the ventilation efficiencies of the cooking fumes of the six exhaust ventilation systems, which were widely being used in the general apartments, houses, and small-food factories. For a comparison of the ventilation efficiencies of the systems, acetaldehyde was chosen as a marker pollutant and its concentrations at the breathing zone of the cook were identified. The laboratory fume hood showed the best ventilation efficiency of the six ventilation systems studied, and then the lateral hood ventilation and the down draft ventilation followed the laboratory fume hood. Finally, this study identified that both a wall factor nearby pollutant sources and a distance factor between the hood face and pollutant sources should be also considered for an effective local exhaust ventilation system design.

• 한국환경과학회지
• /
• 제2권1호
• /
• pp.49-56
• /
• 1993

This study identified the fumes produced from the cooking of the seasoned meats containing various condiments such as garlic, onion, pepper, soy sauce, and sesame oil. Concentrations, at the breathing zone of the cook, of volatile organic compounds (VOCs) and aldehydes included in the cooking fumes of seasoned meats were identified. Many chloro- and fluoro-aliphatic hydrocarbons, aromatic hydrocarbons, ketones, and aldehydes, which could be carcinogen suspecting chemicals, were producing from the cooking fumes of the seasoned meats. This study also identified the ventilation efficiencies of the cooking fumes of the six exhaust ventilation systems, which were widely being used in the general apartments, houses, and small-food factories. For a comparison of the ventilation efficiencies of the systems, acetaldehyde was chosen as a marker pollutant and its concentrations at the breathing zone of the cook were identified. The laboratory fume hood showed the best ventilation efficiency of the six ventilation systems studied, and then the lateral hood ventilation and the down draft ventilation followed the laboratory fume hood. Finally, this study identified that both a wall factor nearby pollutant sources and a distance factor between the hood face and pollutant sources should be also considered for an effective local exhaust ventilation system design.

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

• 설비공학논문집
• /
• 제21권4호
• /
• pp.260-265
• /
• 2009

The aim of this study is to remove crack on a ventilation device at the suction part of zinc plating factory, and the main point is making optimum configuration by improving an existing hood system. The result shows that existing hood system has problem with duct configuration, angle and reducer. Model-5 shows lowest pressure difference as meaning of suction capability. The hood inlet surface has most uniform suction capability.