• 설비공학논문집
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• 제15권6호
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• pp.447-453
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• 2003

The air-side particulate fouling in the heat exchangers of HVAC applications degrades the performance of cooling capacity, pressure drop across a heat exchanger, and indoor air quality. Indoor and outdoor air contaminants foul heat exchangers. The purpose of this study is to investigate the cooling performance and pressure drop on the air-side particulate fouling of heat exchangers for air conditioners. Air conditioners being used in the field such as inn, restaurant, and office are collected in chronological used order. Test results show 15% decrease of the cooling capacity and 44% increase of the pressure drop for the 7 years air conditioners used in the seaside inn.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1473-1478
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• 2003

Scale is formed when hard water is heated or cooled in heat transfer equipments such as heat exchangers, condensers, evaporators, cooling towers, boilers, and pipe walls. When scale deposits in a heat exchanger surface, it is traditionally called fouling. The objective of the present study is to investigate the formation of fouling in a heat exchanging system. A lab-scale heat exchanging system is built-up to observe and measure the formation of fouling experimentally. Water analyses are conducted to obtain the properties of HAN river water. In the present study a microscopic observation is conducted to visualize the process of scale formation. Hardness of HAN-river water is higher than that of tap water in Seoul.

• 설비공학논문집
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• 제16권4호
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• pp.349-354
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• 2004

Scale is formed when hard water is heated or cooled in heat transfer equipments such as heat exchangers, condensers, evaporators, cooling towers, boilers, and pipe walls. When the scale deposits in a heat exchanger surface, it is conventionally called fouling. The objective of the present study is to analyze the process of the fouling formation in a heat exchanger according to different types of water using visualization techniques. In order to experimentally investigate the formation of the fouling, this study built a lab-scaled heat exchanging system. Using the visualization techniques of Scanning Electron Microscopy (SEM) and X-Ray diffraction method, the three dimensional configurations of the fouling formation could be successfully obtained. Based on the experimental results, it was found that the configurations of the fouling formation were different when using tap water compared to river water.

• 대한기계학회논문집B
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• 제20권11호
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• pp.3695-3705
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• 1996

We designed the hot wind tunnel to reproduce the conditions of utility boiler and carried out its performance test, in order to investigate the particulate two-phase flow behaviour, the fouling and heat transfer characteristics to the heat exchanger. The hot wind tunnel introduces the control system to control the temperature in the test section. The particle is injected into the hot gas stream. The fouling probe (cylindrical tube) is positioned normal to the particulate gas-particle two-phase flow and cooled by the air. The temperature of gas and cooling air, and temperature in the fouling probe are measured as a function of time, giving the local and averaged heat transfer and fouling factor. The shape of particulate deposition adhered to the fouling probe is also observed.

• 대한기계학회논문집B
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• 제31권4호
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• pp.330-334
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• 2007

The objective of this study was to investigate the effecs of fouling mitigation for ceramic ball in cooling water system experimentally. The devices filled with ceramic balls were connected to the bypass line of the heat exchanging system. Cooling water in the heat exchanging system was artificial water. To visualize the formation of fouling on the heat transfer surface a number of images were obtained using a CCD camera with real-time microscopy. Fouling resistances and overall heat transfer coefficients were measured in order to analyze fouling mitigation effects. We found that the ceramic ball devices for artificial water reduced the formation of fouling compared to the no-mitigation devices.

• 설비공학논문집
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• 제13권6호
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• pp.482-489
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• 2001

The present study was conducted to estimate the effect on fouling reduction in tubes of the condenser. It shows in detail how to calculate the fouling factor from the experimental results of refrigeration systems with or without the automatic cleaning system using sponge balls and to predict the variation of the factor with time. It also represents how to calculate the temperature and pressure decrease of the refrigerant vapor in the condenser and the load decrease of the compressor in the refrigeration system by fouling reduction.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2003년도 추계학술발표대회 요약집
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• pp.462.1-462.1
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• 2003

• 한국지반환경공학회 논문집
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• 제12권10호
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• pp.51-56
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• 2011

본 연구에서는 스케일형성 제어와 막 파울링 저감을 위한 펄스 전기장 처리의 적용성을 실험적으로 검토하였다. 수용액 중의 칼슘이온 78%가 감소되었으며, $CaCO_3$입자의 크기는 커지는 것으로 확인되었다. 또한, $CaCO_3$의 결정형태는 비교적 제거가 힘든 Aragonite 구조에서 비교적 제거가 쉬운 Calcite 구조로 변화됨을 알 수 있었다. 막투과 유량과 막투과 유속은 펄스 전기장처리전에 비하여 더 높게 나타났으며, 스케일형성 가능성지수인 LI값 역시 감소하는 경향을 나타내었다. 결과로부터 펄스 전기장처리가 막 여과의 전처리로써 $CaCO_3$파울링을 경감시키기 위한 효과적인 방법으로 판단된다.

• 한국전산유체공학회지
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• 제21권2호
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• pp.40-46
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• 2016

In the paper, a study on the analysis of fouling effect of the venturi flowmeter is described. In the research flow field solutions about the venturi flowmeter with fouling are obtained and then the effects on fouling states by inserting a ring into the throat of venturi flowmeter are studied. As the result shows, it is found that the inserted ring reduces the fouling effect due to the flow separation occurring at the ring. Consequently, a venturi flowmeter with ring shows smaller pressure loss differences than the original configuration with no ring on fouling state. This research suggests an efficient and economic method of inserting a ring to reduce the pressure loss effects due to fouling.

• 멤브레인
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• 제24권6호
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• pp.431-437
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• 2014

소수성의 폴리에틸렌 다공성막 표면에 오염물질이 흡착됨으로써 발생되는 파울링 현상으로 인한 투과도 감소 문제를 해결하고자 함산소불소화법을 이용하여 막 표면을 친수화 하였다. 함산소불소화 처리 후 접촉각은 $93^{\circ}$에서 $50^{\circ}$까지 감소하였고, 수투과량은 60% 이상 증가하였다. 또한, 모델오염물질 Albumin (form bovine serum, BSA), Humic acid sodium salt (HA), Alginic acid sodium salt (SA) 100 ppm의 수용액을 이용하여 투과도 평가 실험을 수행한 결과 막이 친수화 됨에 따라 오염물질이 흡착되는 정도가 감소하여 투과도가 향상된 것을 확인할 수 있었으며, 특히 SA에 대해서는 파울링 개선효과가 크게 나타나 처리하지 않은 PE막에 비해 투과도가 두 배 이상 향상된 값을 나타내었다.