Crystallization fouling on modified heat exchanger surfaces

Abstract

<div lang="en" class="abs"><p class="abs_header">Abstract</p><p>Fouling of heat transfer surfaces is a major challenge in design and operation of the process equipment. Fouling decreases economic profitability of processes as well as increases the environmental impact of production. Significant savings could be achieved with even rather small improvements in prevention of fouling of heat transfer equipment. One of the options to prevent fouling on heat transfer surfaces is to modify the heat transfer surface.</p><p>This study investigates the effects of different surface modification methods to prevent fouling on a heat transfer surface by coating, grinding, polishing, and patterning. Fouling behavior of the surface modifications are studied in a laboratory scale fouling test set-up using supersaturated calcium carbonate solution as a test fluid.</p><p>Surface modifications are found to have a significant effect on the fouling induction time when compared to the unmodified stainless steel. The most significant increase in the induction time is obtained by the organosilicon thin films deposited on the stainless steel (AISI 316L 2B) having up to 7.5 times longer induction time of the unmodified reference material. Patterning increases the induction time up to 2.5 times and grinding up to 1.7 times. The mechanism in the fouling reduction seems to be related to chemical functionalization, hydrodynamic effects, and surface morphology.</p></div>