cattani AC 300 Gebrauchsanweisung Seite 21

Compressed air sterilization
(draw. page 70)
Compressed air is filtered several times inside the circuit and conveyed through
a silicagel compound which adsorbs humidity at a temperature within the range
+ 5 °C /+ 35 °C. A pause is needed at every compressor charge in order to regenerate the
silica gel (see below). Filtered and dried air can be considered suitable for instruments and
hygienically safe for dentistry. Air quality can be improved with a sterilizing fi lter (S) to be
installed at the compressor air outlet. The "SA" Balston fi ltering cartridge, with borosilicate
glass microfi ber fi ltering media (T), delivers a 99.9999+% effi ciency on 0.01 µm particles.
Balston fi lters can be sterilized in autoclave at 135 °C (max. 20 cycles); when used
with clean air, life of the fi lters is about 1 year, unless operating conditions require more
frequent substitutions. At this stage the air can be considered as pure, if conveyed into a
reasonably short piping which is not subject to thermal stress.
Large plants
(draw. page 74)
Longer piping, such as those you fi nd in hospitals, clinics, or schools, require a different
air drying system. The recommended air treatment is that of selective membrane, or silica
gel double column with the automatic regeneration and alternation of columns; these
systems guarantee a proper drying of the air, but do not require pauses for regenera-
tion. For large plants we can supply various versions of Blok-Jet units (see pag. 74), with
membrane dryers (produced air: 978-1467-1956 N l/min).
Breathable air or medical air
The oil-free compressor is ideal for producing breathable air for hospitals. In fact, in absence
of oil, no gas that may harm patients is released, therefore evidently the hazardous gas
fi ltering system releasing the air produced by the compressor will be less affected. To
obtain medical air after the compressor, air goes through a series of fi lters remov-
ing all chemical and physical impurities, in compliance with the provisions of the
monograph Issue of the Italian Offi cial Pharmacopoeia. More specifi c and detailed
X
information on medical air is available upon request.
Functioning of compressor
(draw. page 70)
The air enters the cylinder through fi lter (A) and is fi ltered for the fi rst time; this fi lter traps
atmospheric dust, ensuring air cleanliness and thus protecting pistons and cylinders.
Piston (B) slides inside the cylinder (C) without any lubrication; material coating the piston
is compatible with the liner, and in spite of friction both liner and piston are not subject
to any signifi cant wear.
The air is compressed and warmed in the cylinder, therefore it is necessary to convey
it through an air-air exchanger (D) where, at a room temperature of about 20 °C, ∆T is
stable at about 5 °C. Air temperature needs to be reduced to dew point in order to collect
condensation.
Cooled air is then conveyed through cyclon (F) in the drying column (E) thus forming dew,
which is collected in the tank (G). At the top of the column, the air goes through a disk
fi lter (R), and then through a high-adsorption silica gel (I) compound and is completely
dried. Two fi lters are located at the drying column air outlet: the fi rst one is in sintered
bronze (H), the second one in paper (L). Upon request, we can supply a Balston steriliz-
ing fi lter (effi ciency: 99.9999 +% for 0.01 mµ particles). Then the compressed air, dried
and hygienically fi ltered, enters the tank (M) to be used. The tank is coated with certifi ed
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