Induction Period in Crystallization Fouling

A period of the fouling process in which there is no visible deposition and the fouling resistance is not yet positive is usually called the induction period. Depending on the heat transfer and operational conditions, the induction period may be occurred or not. Applying methods that lead to an increase in the induction period has recently been considered as modern fouling mitigation strategies. Contrary to the relatively large studies that have been conducted to identify and investigate the factors affecting the fouling growth period, operational parameters effect on induction period are not fully understood and quantified so far. If there is information about the cause of induction period and the factors affecting it, the induction period can be increased and fouling problems in heat exchangers can be greatly reduced or postponed. This study purpose is to investigate and summarize the operational parameters (e.g., fluid velocity, surface and bulk temperature, salt concentration and heat flux) affecting the induction period of calcium salts (e.g., CaSO4, CaCO3 and mixed of them) to identify the areas that have received less attention in the last 50 years.