Influence of electronic antifouling on agglomeration of calcium carbonate

Abstract

Scaling represents a serious problem to many industries. Scaling in pipes leads to an increased pressure drop and often to complete blockage. On heat exchangers, it reduces the heat transfer. It may also lead to unstable operation which could result in unscheduled shutdown and loss of revenue. One of the most common types of scaling is due to calcium carbonate. Calcium carbonate scaling occurs when Ca ++ and CO 3 − − ions in water react to form an insoluble solid. This research is focused on understanding the behaviour of calcium carbonate agglomeration and scaling in the presence and absence of electronic antifouling (EAF). The novelty of this work is that an inline in situ monitoring technique is utilized to obtain real-time data of the calcium carbonate deposition on a surface. The calcium carbonate crystals are obtained by standard precipitation and agglomeration processes and the formation and deposition of the crystals is monitored using an inline technique known as focused beam reflectance measurement (FBRM). The experimental work has been designed to understand the effect of EAF on precipitation, agglomeration and scaling of calcium carbonate at given calcium ion concentration and solution temperature. The scaling is characterized by measuring the rate of number of crystals deposited on a surface of the FBRM which, unlike mass measurement as used by previous workers, makes this method unique.