Getting Technical
Continued from page 47
which is acknowledged on their website. The product generates
electromagnetic fields through solenoid coils wound onto water
pipes as shown in Figure 3.
Electromagnetic
Induction coils
Control panel
Figure 3
Enigma NCWT units, then called ‘Scalewatcher’ first came
to South Africa in 1989. A current unit as shown in Figure 4
appears to be virtually identical to the 1989 version but, as
mentioned, there has been considerable development. In a
similar vein, the British Ford Motor Co. explained why their
Cortina high performance GT car looked identical to earlier
standard models by stating that, “It appears the same but
disappears differently.” A neatly descriptive phrase for a
machine which looks no different but has much improved
performance. The improvement in the current Enigma unit
range has resulted from developments since 1989 producing
extended ranges of electromagnetic fields which improve
scale inhibition in waters containing various levels of hardness-
producing dissolved solids.
NWCT works in alkaline
conditions of non-corrosive but
potentially scale-forming water
chemistry so the primary task of
NCWT is to control scale.
The other NCWT product which was introduced to South Africa
by AWA Water Management in 1989 was the German Aquasal
range. Aquasal units subjected potentially scale-forming water to
high frequency alternating electrical impulses as it flowed through
concentric stainless-steel electrodes. From the original Aquasal
range, AWA Water Management developed their own proprietary
brand of NCWT scale-control Aqualec systems.
DOES NCWT WORK IN PRACTICE?
Referring again to Stephen Lower at Vancouver University,
when addressing the question ‘Does NCWT work in practice?’
www.hvacronline.co.za
Figure 4
he states, “There are too many favourable anecdotal reports to
dismiss it entirely.” Until recently, many NCWTs manufacturers
claimed that monitoring of water chemistry was not required
because their products worked without changing water
chemistry even though calcium carbonate is precipitating.
However, scaling chemistry dictates that calcium carbonate
precipitation requires a change in the soluble ion concentration
and therefore a change in pH due to a reduction in the
concentration of carbonate alkalinity. More manufacturers and
suppliers of NCWT products are now starting to include water
chemistry tests which support their case histories.
Another technical aspect which has come into play over the
past ten years or so is that the NCWT industry is recognising
that in certain potentially scaling water circuits, even possibly
in a majority of such circuits, the optimum water treatment
programme may well be NCWT in combination with long proven
traditional chemical dosing for this purpose. Amongst many
positive reports to this effect is an interesting one from the
Environmental Treatment Concepts website.
Following extensive work carried out in the US by an
associate company, Electronic Descaling 2000 (ED2000), the
massive savings to be made by adopting Electronic Water
Conditioning are not too difficult to identify. No changes to
the chemical treatment programme are necessary. In fact,
there is clear evidence that the two technologies complement
each other.
Chemical water treatment companies no longer dismiss non-
chemical ‘water treatment devices’ as gimmicks or ‘gizmos’. It is
now widely accepted that NCWT, either alone or combined with
chemical treatment, are genuine and environmentally-friendly
methods of achieving better energy efficiency and reducing
water usage. RACA
REFERENCES:
1. Cho, Y. I., Fan. C., Cap, B-G, Theory of Electronic Anti-fouling Technology
to Control Precipitation Fouling in Heat Exchangers, Int. Comm. Heat
Mass Transfer 24 pp 757-770 (1997).
2. Stephe n Lower. Ex Faculty Member. Vancouver University.
RACA Journal I February 2020
49