• 한국산학기술학회논문지
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• 제14권3호
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• pp.1519-1526
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• 2013

본 연구에서는 현장조사를 통해 주물 제조 사업장의 일부 용해공정에 적용되고 있는 캐노피 후드(canopy hood)의 흡인 성능을 검토하였다. 또한, CFD model을 이용하여 유해대기오염물질 포집 능력을 향상시킬 수 있는 방안들을 대한 유동장 및 압력장을 비교 및 평가하였다. Case-2(플랜지 부착+이중 후드)의 경우 포집 성능 측면에서는 개선이 가능하지만 후드 정압이 기존 구조보다 약 70% 이상 증가할 것으로 예측되어 현장 적용성이 좋지 않을 것으로 나타났다. 흡인효율을 개선하기 위해서는 case-3(플랜지 부착+이중 콘 부착)의 형상이 가장 적합할 것으로 판단된다. 이는 개구부 중앙에 이중 콘(cone)이 설치되어 후드 가장자리로 유량을 집중시킬 수 있으며, 또한 후드 중앙으로 상승되는 흄(hume)은 콘의 기울기에 의해 정압 상승의 요인 없이 제어할 수 있기 때문이다.

• 한국환경과학회지
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• 제5권6호
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• pp.683-697
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• 1996

Industrial ventilation is a crucial engineering measure to protect workers from hazardous airborne contaminants. Designing a ventilation system is not an easy task. To solve this problem, many U. S. computer programs and softwares have been developed. In Korea, asoftware, called as VPMC, was developed by Korea Industrial Safety Corporation. But VPMC could not stand alone since it can be used to design not a hood, but a ventilation system. In this research, therefore, a preprocessing software was developed. It can be used to design general ventilation system, canopy hood, open surface tank hood. The program was written in Microsoft Visual Basic. In near future, this software will be incorporated into a total package software which can be used to design a whole ventilation system.

• 기술사
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• 제45권6호
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• pp.44-51
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• 2012

Local functional, closed the hood and exhaust are classified as open-style hood. Around the closed hood contaminants prevent the spread of contaminants. Surrounded Some pollutants (open-style hood is used in cases where the odor, vapor diffusion, and inferior) of indoor allowed to Hood expressions, which are used for kitchen, laboratory, factory canopy is typical. Contamination that occurs during cooking, kitchen ventilation barrier materials are the biggest problem, its solution by introducing fresh outside air in the kitchen troubleshoot and. Study on the kitchen exhaust airflow for my kitchen, and perform a number of each Institute and at the University of hydrodynamic analysis is investigated.

• 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).

• 한국산업보건학회지
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• 제11권1호
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• pp.1-8
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• 2001

This study was performed to evaluate a local exhaust ventilation system capability and welding fume concentration in welding laboratory at 5 technical high schools. Results of the study are as follows; 1. The personal exposure of welding fume in welding laboratory was measured. The geometric mean of 73 personal samples was $6.27mg/m^3$($3.85{\sim}9.88mg/m^3$), and 68.5% of these exceeded TLV of the Korea Ministry of Labor. 2. The geometric mean of welding fume at outside of booth was $2.27mg/m^3$($1.57{\sim}2.58mg/m^3$). All of measured concentrations were lower than TLV of the Korea Ministry of Labor. 3. Local exhaust ventilation system in welding laboratory could not remove hazardous substance effectively because of inappropriate canopy hood and absurd design. 4. The possibility of exposure risk was estimated to be high because of working point under breathing zone, misplacement of working table and insufficient supply of respiratory protector. 5. The mean values of capture velocity and transportation velocity of local exhaust ventilation system in welding laboratory were 0.38m/sec, 4.27m/sec respectively. These values were satisfied the guideline of the Korea Ministry of Labor. 6. The efficiency of performance of local ventilation system was anticipated to be decreased because of accumulated dust and alien substance on fan and duct.

• 한국산업보건학회지
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• 제26권2호
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• pp.225-236
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• 2016

Objectives: Nanomaterials have been used in various fields. As use of nanoproducts is increasing, workers dealing with nanomaterials are also gradually increasing. Exposure assessments for nanomaterials have been carried out for protection of worker's health in workplace. Exposure studies were mainly focused on manufacturing processes, but these studies on after-treatment processes such as refinement, weighing, and packing were insufficient. So, we investigated exposure characteristics of particles during after-treatment processes of $Al_2O_3$ fibers and Ni powders. Methods: Mass-production of Ni powder process was carried out in enclosed capture-type canopy hood. In a developing stage, $Al_2O_3$ was handled with a local ventilation unit. Exposure characteristics of particles were investigated for $Al_2O_3$ fiber and Ni powder processes during the periods of 10:00 to 16:00, 20 May 2014 and 13:00 to 16:00, 21 May 2014, respectively. Three real-time aerosol instruments were utilized in exposure assessment. A scanning mobility particle sizer(SMPS, nanoscan, model 3910, TSI) and an optical particle counter(OPC, portable aerosol spectrometer, model 1.109, Grimm) were used to determine the particle size distribution in the size range of 10-420 nm and $0.25-32{\mu}m$, respectively. In addition, a nanoparticle aerosol monitor(NAM, model 9000, TSI) was used to measure lung-deposited nanoparticle surface area. Membrane filters(isopore membrane filter, pore size of 100 nm) were also used for air sampling for the FE-SEM(model S-5000H, Hitachi) analysis using a personal sampling pump(model GilAir Plus by 2.5 L/min, Gilian). Conclusions: For Ni powder after-treatment process, only 27% increase in particle concentration was found during the process. However, for $Al_2O_3$ fiber after-treatment process, significant exposure(1.56-3.34 times) was observed during the process.

• Tuberculosis and Respiratory Diseases
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• 제46권6호
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• pp.836-845
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• 1999

연구배경 : 수면 무호흡증 환자는 대부분 비만이 동반되고 비만은 수면 무호흡증 발병의 중요한 원인으로 알려져 있다. 또한 체중을 줄임으로써 무호흡 횟수 및 심부정맥의 감소와 동맥혈 산소포화가 향상된다는 사실이 알려지면서 체중조절을 중요한 치료방법으로 생각하게 되었다. 그러나 지금까지 비만에 대한 다양한 치료방법이 시도되었으나 결과는 만족스럽지 못하다. 저자들은 체내에너지 대사의 대부분을 차지하는 안정시 에너지대사의 변화를 관찰하고 수면다원검사에서 측정한 수면무호흡증의 중증도와 안정시 에너지소모량과의 상관관계를 규명하여 무호흡의 중증도가 안정시 에너지대사에 미치는 영향을 알아보았다. 또한 수면 무호흡증에서 혈중 leptin 농도를 측정하여 수면 무호흡의 중증도와 leptin과의 상관관계를 알아보기 위하여 이 연구를 수행하였다. 방 법 : 수면 중 무호흡 증상을 주소로 내원하여 수면무호흡증으로 진단 받은 환자 중 신체질량지수가 $25\;kg/m^2$ 이상인 39례와 비슷한 비만도를 보이며 수면무호흡이 없었던 45례를 대상으로 수면다원검사를 실시하고 안정시 에너지소모량은 ventilated hood system을 이용하여 indirect calorimetry로 측정하였다. 수면무호흡증과 대조군에서 혈중 leptin 농도는 human leptin kit를 사용하여 측정하였다. 결 과 : 수면무호흡증은 대조군보다 안정시 에너지소모량의 예측치와 측정치가 유의하게 높았으나, 안정시 에너지 소모량 백분율은 차이가 없었다. 안정시 에너지소모량은 수면무호흡증의 중증도와 관계 있는 무호흡지수, 무호흡 저호흡지수 및 최저 동맥혈 산소포화도 등과도 상관관계는 없었다. 수면무호흡증에서 혈중 leptin 농도는 무호흡지수, 무호흡 저호흡지수 및 최저 동맥혈 산소포화도와 상관관계가 있었으나, 안정시 에너지소모량과 상관관계는 없었다. 결 론 : 이상의 결과로 수면무호흡증에서 안정시 에너지대사가 감소되어 있지 않았으며 수면무호흡증에서 leptin은 안정시 에너지소모에 관여하여 지방을 조절하기보다는 식이를 조절함으로써 체지방을 조절할 것으로 생각한다. 수면무호흡증에서 무호흡의 정도가 심할수록 혈중 leptin 농도가 높았으며 이는 수면무호흡증에 동반된 비만과 관계가 있을 것으로 생각하며, 수면무호흡증에서 leptin 농도와 무호흡의 중증도와의 관계에 대해서는 더 많은 연구가 필요할 것으로 생각한다.