• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.10
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• pp.530-537
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• 2017

Scales generated inside pipes cause negative effects on heat transfer performance, pressure loss and flow rate due to increased thermal resistance and reduced flow cross-sectional area. If these scales are not prevented or eliminated, thermal-fluid performance of the facilities can be deteriorated, or in extreme cases, accidents such as explosion due to overheating can occur. There are two ways to remove the scales, physically and chemically. Removing the scales physically needs specific machines which are expensive, and removing them chemically may provoke corrosion or shorten the age of the facilities. In this study, an eco-friendly pipe scale cleaner using natural organic acid is developed by applying the concept of a limestone cave generation. The manufactured scale cleaner is applied to remove the scales in industrial, water heating and urinal pipes. The results show that this cleaner removes scales more effectively and safely compared to existing scale treatments. Scale removal efficiencies of this work is 1.2~10.7 times for industrial pipes and 1.8~15.5 times for boiler water heating pipes higher than those of conventional cleaners.

• Applied Biological Chemistry
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• v.45 no.3
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• pp.179-184
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• 2002

To examine utilization of Korean black soybean as a natural pigment, the effects of temperature, carbohydrate, organic acid, vitamin C and metal ion were investigated. Korean black soybean pigment was more stable than other anthocyanin pigments when temperature was abused. There was no darkness effect in carbohydrate. In organic acid, the color intensity was increased. The vitamin C addition negatively affected on color of anthocyanin. Among the metal ions tested, $Cu^{2+}$ and $Zn^{2+}$ was not affected but $Mn^{2+}$ makes it unstable. Results indicate that Korean black soybean pigment was more stable than other anthocyanin pigment in various environment at pH 3.