Influence of Solution Hydrodynamics on the Deposition of CaSO4 Scale on Aluminum

摘要

The dissolution of hard and adherent scaling species depositing from process fluid streams is a serious problemnexperienced by the world’s processing and petrochemical industries. Scaling/fouling causes a significant economicnloss. Scaling is a complex process; therefore, this laboratory study employed a rotating cylinder electrode apparatusnto develop a basic understanding of the scaling phenomenon. The effect of solution hydrodynamics was investigatednat various rotational speeds on the deposition of calciumsulfate (CaSO4) scale on aluminumsubstrate having surfacenroughness profiles produced with 120 and 600 grit silicon carbide emery papers and at temperatures of 60 and 70u0001nC.nThe results indicate a strong impact of solution hydrodynamics on the deposition rate of calciumsulfate on aluminumnspecimens. Morphological examinations of the deposited scale crystals under scanning electron microscope andnenergy dispersive X-ray spectrometry revealed prismatic needles and rodlike crystals growth at nucleation sitesnbranching out randomly over the substrate. Secondary growth on the already existing primary crystals of CaSO4nwas also discerned.