CACO3 SCALING IN AISI-316-STAINLESS-STEEL TUBES - EFFECT OF THERMAL AND HYDRAULIC PARAMETERS ON THE INDUCTION TIME AND GROWTH-RATE

Calcium Carbonate (CaCO3) is predominantly present in cooling water wh ich is commonly used as a coolant in many industrial processes. It has inverse solubility characteristics i.e., it is less soluble in warm w ater, resulting in the deposition of scale on heat transfer surfaces. An experimental study was carried out to determine the effect of tube surface temperature, Reynolds number, tube diameter and salt concentra tion on the induction time of CaCO3 scaling. It was observed that tube surface temperature, Reynolds number and tube diameter had no effect on the onset time of scaling, whereas salt concentration and tube surf ace roughness had a profound influence on the induction period. The da ta collected from the experiments were used to develop dimensionless f ouling resistance models for estimation and prediction purposes.