Investigation on fouling of enhanced tubes used in a cooling tower water system based on a long-term test.

In order to investigate the fouling of enhanced tubes, a continuous fouling test on eight enhanced tubes and one plain tube was conducted for 98 days, using a medium fouling potential water as the test water at a water velocity of ~1.6 m/s. Four periods were defined for fouling development based on the test data in this work: introduction period, initial deposit period, rapid deposit period, and stabilization period. The rank of asymptotic fouling resistance of nine test tubes was as follows: Tubes 9 > 7 > 6 > 5 > 1 > 3 > 4 > 2 > 8. The pressure drops of the nine tubes increased by 0.1 kPa to 1.32 kPa due to fouling deposit at the end of the fouling test. A fouling resistance prediction model was developed, which had a maximum error of 0.0645 for predicting the fouling resistance ratio.