Conference Dates

July 1-6, 2007

First Page



The influence of different materials on the fouling tendency in saline calcium sulfate solution was investigated. The effects of the untreated material on the crystallization process have been studied experimentally in the micro- and macroscopic scale. The crystallization in the induction period was visualized with SEM and AFM to locate preferred nucleation spots and to visualize the crystal growth. The different materials are showing different crystal growth behavior (number and size of the crystals). These results are corresponding with the macroscopic fouling results with limited shear stress. Also different roughness values on stainless steel have been studied with respect to fouling tendency. The induction time can be extended with smoother surfaces due to the limitation of nucleation spots. With higher fluid velocities, the adhesion of the forming crystals on the heat transfer surface dominates the length of the induction time.