• 설비공학논문집
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• 제15권7호
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• pp.611-617
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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 characteristics of the air-side particulate fouling materials in finned-tube heat exchangers of air conditioners. Air conditioners being used in the field such as inns, restaurants, and offices are collected in chronological order in use. Typical fouling materials on the heat exchangers include fibers and dusts ranged from 6.6 to 20.9 ${\mu}{\textrm}{m}$ in mass median diameter.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1582-1588
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• 2004

The present experimental study aimed to investigate the feasibility of physical water treatment (PWT) devices using catalytic materials to mitigation of crystalization fouling. Two PWT devices having different shape and material were used. The results from microscopic observation and SEM photographs demonstrate that the crystal structure of $CaCO_3$ is Argonite type without water treatment while Calcite type with water treatment, which clearly shows the feasibility of PWT techinque using catalytic materials to mitigate crystalization fouling. For 500 ppm solution, the fouling resistance decreased up to about 23% due to physical water treatment using catalytic materials. The results also reveal that if two more techniques are used simultaneously the additional effects could be expected.

• 멤브레인
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• 제29권5호
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• pp.276-283
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• 2019

본 논문에서는 축전식 탈염 공정에서 파울링 현상의 확인과 파울링의 제거공정 조건을 확립하는 연구를 진행하였다. 공급액에 첨가된 파울링 유발 물질인 Humic acid sodium salt (HA)의 농도는 5, 10, 15 mg/L이었다. 주어진 일반의 흡/탈착 조건에서 파울링의 발생은 시간이 지남에 따라 흡착과 탈착 농도의 증가로 확인할 수 있었다. 파울링 현상을 제거하기 위해 흡착 및 탈착에서의 전압과 시간을 변경하였다. 이로부터 흡착 조건 1.2 V/5 min, 탈착 조건 -3 V/2 min에서 파울링 제거를 확인하였다.

• Korean Membrane Journal
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• 제3권1호
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• pp.17-23
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• 2001

Polyethersulfone (PES) and cellulose acetate (CA) ultrafiltration (UF) membranes having different molecular weight cut-off values were prepared by immersion precipitation method by changing the compositions of easting solution. Egg white solution was concentrated to volume concentration ratio 4 in tubular UF with membranes made of moderately hydrophobic PES and hydrophilic CA. The process Parameters such as pressure and fluid velocity were controlled in order to apply successfully for egg white solution and to investigate the pressure dependency. The resistance values were measured to investigate the fouling and concentration polarization effect on membrane performance. During concen- tration of egg white solution by UF, the fouling layer appeared to contribute little resistance to flux compared to that of polarized layer.

• 한국재료학회지
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• 제7권9호
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• pp.750-757
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• 1997

발전소 복수기의 열전달 표면에 형성되는 불순물의 fouling factor와 튜브내면에 부착되는 피막의 두께변화를 측정하여 복수기 관리에 관한 지침을 제시하고자 모델복수기를 이용하여 60일간 현장실험을 실시하였다. 복수기의 fouling factor는 시험 후 약 40일 이후부터 큰 폭으로 증가하였다. 발전용 복수기의 관청결도가 85-90%로 설계되므로 설계치를 유지하기 위해서는 약 40일 마다 복수기튜브를 세정하여 관청결도를 향상시켜야 할 것으로 판단되었다. 또한 동합금 재질을 사용하는 복수기튜브는 설치 후 보호피막이 형성되는 초기 30일 동안의 방식운전이 복수기튜브 건전성 확보에 중요한 인자임을 유추할 수 있었다.

• 멤브레인
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• 제30권5호
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• pp.342-349
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• 2020

본 연구에서는 자연수, 하폐수에 많이 포함되어 있는 파울링 유발 물질 중 하나인 alginic acid sodium salt를 축전식 탈염공정(capacity deionization, CDI)에서 파울링 감소를 위한 조건을 확립하고자 한다. 먼저 feed 물질로 NaCl을 사용하였다. 이는 파울링 발생에 대한 비교 물질로, 파울링이 발생하지 않음을 관찰하였다. Alginic acid sodium salt를 사용하여 파울링 발생 여부를 확인하였다. 농도는 7 mg/L, 흡착 1.2 V 5 min, 탈착 -2 V 1 min에서 효율이 50.07%으로 제일 효율적인 탈착 조건임을 알 수 있었다.

• 대한기계학회논문집B
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• 제29권11호
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• pp.1229-1238
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• 2005

The objective of the present study was to investigate the efficacy of physical water treatment (PWT) technologies using different catalytic materials and an electronic anti-fouling device in the mitigation of mineral fouling in a once-through flow system with mini-channel heat exchanger. Effects of flow velocity and water hardness on the effectiveness of PWT technologies were experimentally studied. The artificial water hardness varied from 5.0 to 10 mo1/m$^{3}$ as CaCO$_{3}$. For 10 mo1/m$^{3}$ solution, fouling resistance reduced by 13-40$\%$ depending on flow velocity and types of PWT devices. On the other hand, fouling resistance reduced by 21-29$\%$ depending on the PWT devices for 5 mo11m3 solutions. The PWT device using alloy of Cu and Zn as catalyst (CM2) was slightly more effective than the others. SEM photographs of scale produced from the 10 mol/m$^{3}$ solution at 1.0 m/s indicated that calcium carbonate scales without PWT devices were needle-shaped aragonite, which is sticky, dense and difficult to remove. Scales with the PWT devices showed a cluster of spherical or elliptic shape crystals. Both the heat transfer test results and SEM photographs strongly support the efficacy of PWT technologies using catalytic materials and an electronic anti-fouling device in the mitigation of mineral fouling.

• Transactions on Electrical and Electronic Materials
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• 제18권3호
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• pp.148-150
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• 2017

For the improvement of the anti-fouling features of porcelain electrical insulators, in this study, the surface of an insulator was coated with a functional material to expand the insulator's self-cleanness. The anti-fouling and mechanical features of the functional film coating of ceramic substrates made from components like an electrical insulator were analyzed. The coating methods that were used were spray coating, dip coating, and fabric coating. Following the coating, the contact angle of the coated surface was measured, revealing that the spray coating method offered the lowest angle ($13.7^{\circ}$) and a strong hydrophilic feature. The anti-fouling analysis showed that the anti-fouling features improved as the contact angle decreased. The mechanical properties - hardness and adhesion - were both excellent at 9H and 5B, respectively, regardless of the coating method that was used.

• Animal Systematics, Evolution and Diversity
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• 제35권4호
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• pp.204-217
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• 2019

This study aims to investigate the fouling bryozoans which attach to artificial structures of Korean ports and harbours. The materials have been collected from 56 sites during the period from 2008 to 2012. As a result of the present study, 40 species of fouling bryozoans were identified. The most abundant species are Bugula neritina (Linnaeus, 1758), Tricellaria occidentalis (Trask, 1857), Watersipora subtoquata (d'Orbigny, 1852), and Cryptosula pallasiana (Moll, 1803). Three species, Flustrellidra armata Grischenko, Seo and Min, 2010, Cauloramphus korensis Seo, 2001, and Parasmittina contraria Seo, 1993 are endemic to Korea. A total of 70 species of fouling bryozoans have been reported in Korea with 16 new bryozoans resulting from this study.

• Korean Membrane Journal
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• 제11권1호
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• pp.21-28
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• 2009

We investigated the effect of organic materials on membrane fouling in advanced drinking water treatment by a hybrid module packed with granular activated carbon (GAC) outside multi-channel ceramic microfiltration membrane. Synthetic water was prepared with humic acid and kaolin to simulate natural water resouces consisting of natural organic matter and inorganic particles. Kaolin concentration was fixed at 30 mg/L and humic acid was changed as 2~10 mg/L to inspect the effect of organic matters. Periodic back-flushing using permeate water was performed for 10 sec per filtration of 10 min. As a result, both resistance of membrane fouling (Rf) and permeate flux (J) were influenced highly by concentration of humic acid. It proved that NOM like humic acid could be an important factor on membrane fouling in drinking water treatment. Turbidity and UV254 absorbance were removed up to above 97.4% and 59.2% respectively.