16
JUDO BIOSTAT-COMBIMAT
Operation
5.2.2 Lime protection function
The water treatment devices sets free the
minute seed crystals to which further lime
can attach itself. In the treatment section,
there is a titanium anode (positive pole) and
a circular stainless steel brush switched as
the cathode (negative pole). As soon as
water flows, there is a pulsating direct
current applied to these two electrodes so
that there is a flow of electricity between the
electrodes. Dissolved calcium in the form of
calcium carbonate crystals is then deposited
on the cathode (the circular stainless steel
brushes). On cleaning, these crystals of
calcium carbonate are thrown off the sepa-
rate bristles by rotating the circular brush.
The crystals thus formed are minute micro-
crystals. Larger crystals which may possibly
also appear sink together with separate
loose brush particles to the bottom and are
flushed out via the flushing valve during
cleaning.
The lime particles can be seen in the
flushing water as very fine "sand". The
microcrystals remain in suspension and
thus form seed crystals on which further lime
can be deposited. Principally in the warm
water field the growth of the crystals can be
realized by a gradual clouding of the water.
The crystals slowly grow large enough to be
able to disperse the rays of light. At that
stage, they are but a few thousandths of a
millimeter in size. But even these crystals
are small enough to remain in suspension
and to be flushed out with the water flow.
The same process goes on in the cold water
field, too, although the potential here for
deposition of lime is considerably less in
normal circumstances. Since the excess
lime (calcium) is now deposited at the seed
crystals, other surfaces (e.g. pipework,
boiler etc.) are not affected by lime deposits
so that heating elements for example no
longer fur up. Although this formation of
crystals does reduce the hardness of the
water, the reduction is so small that they
remain undetectable by means of simple
measuring instruments.
In the feed of the unit, is a propeller water
meter which can even detect such small
flows of water as 1.5 l/min. Together with a
microprocessor-controlled electronics,
optimal water treatment is ensured at all
times from tiny flows up to the nominal
capacity, and also depending on the water
quality by adapting the electrical impulses.