Every household and every factory uses water,
and none of it is pure. "Water hardness" refers to
the presence of dissolved ions, mainly of calcium Ca2+ and
magnesium Mg2+..
Their positive electrical charge are balanced by
anions (negative ions), of which the most important are bicarbonate
HCO3– and
carbonate CO32–.
Carbon dioxide reacts with water to form carbonic acid which is usually found as the bicarbonate ion.
Microscopic marine organisms use this carbonate to form their calcite skeletons. Their accumulated remains, over millions of years,
build up extensive limestone deposits. Groundwaters, acidified by carbon dioxide, dissolve the limestone and thus carries with it into aquifers
calcium and bicarbonate ions which make the water "hard".
In high concentrations calcium carbonate ("lime scale") will precipitate out on surfaces such
as the insides of pipes.
These dissolved calcium and magnesium ions react with soaps, causing them
to form an unsightly scum; the familiar "bathtub ring". More seriously,
the calcium and magnesium carbonates precipitate out as scale on
the surfaces of pipes and especially on hot heat exchanger surfaces. The
scale buildup can impede water flow in pipes and acts as thermal insulation,
reducing heating efficiency.
Certain magnetic
and electromagnetic devices have been reported as being effective
in some circumstances, in preventing scale formation in hard water
systems. While the lack of completely verfied scientific evidence
does not in itself invalidate a claim for the efficacy of a device,
it should make one hesitate to accept it without some guarantee of
performance.
Many of of these devices claim to work by causing the carbonate
salts to precipitate
as small particles within the water instead of forming scale deposits.
This should also reduce scum as there would be a lower concentration
of calcium and magnesium ions to react with soaps.
Klaus
Kronenberg reported changes in the morphology of
calcium carbonate crystals formed upon evaporation of a solution
that had been passed through a magnetic field.
Szkatula,
Balanda and Kopec in Poland, reported success with magnetic
scale control in the presence of silica.
Magnetic treatment of industrial water. Silica activation A.
Szkatula, M. Balanda, M. Kopec:European Physical Journal - Applied
Physics 18 41-49 2002
This study suggested that when silica
is present in the water, it forms colloidal particles whose
electric double layer, when distorted by an external magnetic
field, tends to adsorb calcium and magnesium ions, thus inhibiting
their precipitation on heat exchanger surfaces. Once formed,
these adsorption complexes can remain intact for some time, thus
explaining the "memory" effect
that has been noted before. The crucial role of silica hydrosol
may help explain why MWT appears to control boiler scale in some
instances but not in others.
A more recent and detailed study by Coey has found that magnetic treatment encourages the growth
of aragonite, the less-stable (more soluble) form of calcium carbonate.
Magnetic Water Treatment. J.M.D. Coey and Stephen Cass, J.
Magnetism Magnetic Materials 209 (2000) 71-74. This study
examined the scale formed by heating hard water in open vessels
to below the boiling point. Tests on 32 pairs of samples revealed
that drawing the water through a static magnetic field of 0.1T
(10 T/m) increases the aragagonite/calcite ratio on the deposit.
There is an incubation period of several hours, and memory of
magnetic treatment extends beyond 200 hours.
This is the first rigorous study showing that MWT can have a lasting
effect on the nature of calcium carbonate deposition, and supports
some of the results discovered some time ago by Kronenberg. The
authors discuss several possible mechanisms, one of the more plausible
being that trace amounts of iron in the water form paramagnetic
FeOOH clusters that are retained and which eventually serve as
nucleation centers which favor the formation of aragonite. Aragonite
is one of the two principal crystalline forms of CaCO3.
It is slightly less stable (more soluble) than calcite and in these
experiments it tended to form elongated needle-like crystals.
Many
water-treatment engineers who have investigated magnetic water treatment
(MWT) in industrial settings report negative results. However, there
are also many claims that MWT is effective for scale control,
and probably too much anecdotal evidence for its effectiveness
in this particular application to dismiss it completely. Many scientists
who have looked into MWT remain sceptical, as they tend of be of
any field for which there is no obvious theoretical model and in
which quantitative and reproducible results are hard to come by.
Scientists who might otherwise be qualified to investigate MWT also
tend to be put off by the stigma the field has aquired due to the
exagerated claims made by some of its adherents and the widespread
promotion of various worthless applications involving magnets. The
'noise' created by the charlatans in the field does not mean
that all magnetic products are, therefore, worthless. As most scientifically
valid studies suggest that the conditions under which MWT
can work are still not understood, more research, rather than less
is needed into MWT.
For those contemplating the purchase
of a MWT device, establish definite, testable,
criteria to define what "it works" means in your application, and
then make your purchase only from a company that is willing to
offer a performance guarantee based on these criteria.
Many customers
of the patented H2Flow product have found it effective. H2Flow
is a solid strontium ceramic device with six polarity changes
along its length, creating an alternating magnetic field in the water
passing through the pipe the device is attached to. While most users
have found that it works, some report disappointing results. The
experimental results suggesting that the presence of traces of contaminants
such as silica or iron is important may have a bearing on this. H2Flow
is produced by Ecoflow and comes with a 90-day, no-quibble 100% money-back
warranty.
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