화학공학소재연구정보센터
International Journal of Heat and Mass Transfer, Vol.42, No.8, 1491-1499, 1999
Validation of an electronic anti-fouling technology in a single-tube heat exchanger
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 CaCO3. 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.