The NaturalSof unit ( Figs 2 and 3 ), never more than 1m long, is plumbed into the system it is meant to protect. The standard unit is an apparently simple device; water is made to flow past a special alloy insert in a length of pipe.
If the unit is to work, it must change the water as it flows past. It must, in some way, reduce the supersaturation ratio of the water, i.e. the free Ca++ and free CO3– ions must be reduced. The most obvious way would be by precipitating them as calcium carbonate – much like lime softening techniques.
Because of the composition of the unit, there are only two ways in which it can work. First, the special alloy could either adsorb ions from the solution or corrode. Either event could increase the pH locally, increase the Sr locally, and cause precipitation of calcium carbonate, thus providing the desired result that downstream of the NaturalSof the water is part-softened and carries suspended calcium carbonate crystals. Secondly, the shape of the unit promotes turbulence; the associated pressure differences could cause dissolution of CO2 gas which may get stripped from the water when it becomes open to the atmosphere, in a cooling pump for example, and therefore reduce the total carbonic species in the water.
The second method is independent of alloy composition, but copper or zinc inserts, for example, do not work in practice. We are therefore drawn to the first, the special alloy, effect mechanism.
A research program at the UKAEA Harwell laboratory was commissioned to study the behavior of a number of synthetic hard waters, simulating typical waters experienced in practice, under carefully controlled conditions. Waters 1 and 2 were hard waters ( 350ppm as CaCO3 ) at different pH levels, 3 was a less hard water ( 250ppm as CaCO3 ) and 4 was simulated sea water.
1) Does NaturalSof alloy give rise to increases in pH of the water?
NaturalSof alloy granules were washed in distilled water, and were air dried and 35g samples were added to 500ml of synthetic water. The flasks were stoppered, shaken from time to time and the pH monitored. Fig 4 shows the results for each of the waters.