RACA Journal February 2020 | Page 48

Getting Technical together to form precipitates. My best guess, based on the most recent literature, is that applied magnetics and electric fields might distort the double-layer in such a way as to promote nuclei formation, particularly if certain other ions are present such as iron, zinc, sulphur, phosphorous or copper which have been identified as promoting nucleation and subsequent crystallisation in high scaling potential water solutions. Crystal formation in water flows takes time, starting when dissolved calcium cations and carbonate radical anions recombine creating calcium carbonate molecules which precipitate out of solution and bond together forming tiny ‘seed crystals’. These seed crystals act as preferential sites for further precipitation as well as agglomerating with other precipitated crystals resulting in general crystal growth throughout the whole volume of the water flow or circuit. The time between initial precipitation as a seed crystal and subsequent growth to a size which can no longer be carried by flowing water can vary widely from minutes to days, or even weeks, depending on many chemical and physical variables in the water volumes. The fact that electromagnetic application can accelerate crystal formation is now widely accepted. This combination of faster crystallisation occurring in the flowing water volume itself and not preferentially on heat exchange and other wetted surfaces, as happens in untreated water, is generally thought to be the essential mechanism that prevents (or reduces) scaling. Researchers using scanning electron microscopes and X-ray diffraction spectroscopy have measured NCWT produced crystals and generally agree that these crystals are 30% to 50% more numerous and have calculated masses between three and ten times those derived from water with no NCWT. 46 RACA Journal I February 2020 Figure 1 Figure 2 www.hvacronline.co.za