Validation of an electronic anti-fouling technology in a single-tube heat exchanger

• Published in: International journal of heat and mass transfer 1999-04, Vol.42 (8), p.1491-1499
• Main Authors: Cho, Y.i., Choi, Byung-Gap
• Format: Article
• Language: English
• Subjects: Applied sciences; Devices using thermal energy; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Heat exchangers (included heat transformers, condensers, cooling towers)
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/S0017-9310(98)00196-3

The objective of the present study was to investigate the validity of an electronic anti-fouling (EAF) technology in the mitigation of precipitation fouling in a once-through flow system with a single-tube heat exchanger. Effects of flow velocity and water hardness on the effectiveness of the EAF technology were experimentally studied. The water hardness varied from 7.5 to 10 mol m −3 as CaCO 3. For both 7.5 and 10 mol m −3 solutions, the EAF treatment reduced fouling resistance by 20–38% at a flow velocity between 0.52 and 0.78 m s −1. As the velocity decreased to 0.28 m s −1, the EAF treatment was not helpful in reducing fouling. SEM photographs of scale produced from the 10 mol m −3 solution at 0.78 m s −1 indicated that calcium carbonate scales without the EAF treatment were needle-shaped aragonite, which is sticky, dense, and difficult to remove. Scales with the EAF treatment showed a cluster of elliptic shape crystals. Both the heat transfer test results and SEM photographs obtained in the present study support the validity of the EAF technology in mitigating precipitation fouling.