Foreword
"FIC" are filters generally designed to remove
chloride and free ozone, absorb organic macromolecules such as surface-active agents,
tannins, hydrocarbons, solvents, compounds and chlorine derivatives (which are the cause
of undesirable odors and an unpleasant taste), pesticides and organic microscopic
pollutant agents to be found in water intended for human consumption. The FIC filters are
not generally used for removing water turbidity owing to suspended particles which might
occlude the pores of the activated carbon and limit its absorbing power.
They are, in fact, almost always called for downstream of clarifying or
deferrization-demanganization filters. The "FIC" filters may be fitted with an
optional chlorite of sodium feed unit and contact tank in order to encourage the ammonia
oxidation process with break-point chlorination. The filter bed is composed of a
mineral-type granulated carbon with a powerful dechlorination and absorbing action. The
underbed is composed of quartz sand with a suitable granulometry.
Structural features.
TANK: made from carbon steel, vertical cylinder type with
convex bottoms, complete with lower manhole, upper handrail, connections for the filter
inlet-outlet, upper connection for bleeding, lower connection for emptying the bottom,
supporting legs and grommets for lifting.
The lower distributor is to be found inside the tank, made up of a central casing and
distribution arms with precisely sized slits, together with the upper distributor. From
the 180 model up, the tank is characterized by a lower distribution plate complete with
filtering nozzles and an additional manhole. The surfaces inside are subjected to SA 2.5
with metal sandblasting and given two coats of epoxy-based paint suitable for contact with
foodstuffs. The outside is sandblasted, given a coat of primer and a polyurethane-based
finish (RAL 5015).
The hydraulic unit for the operating phases and washing of the filter, made up of nº5
hydraulic or pneumatic valves of the type with cast iron diaphragm, nº2 flow restrictors;
1 brass ball valve each for the bleeding and the manual emptying of the water in the tank;
nº2 gauges placed upstream and downstream from the filter, complete with valve on which a
gauge can be fitted; pipes and pipe fittings connecting the valves to the tank in
galvanized iron. From the model 180 up, the valves are butterfly-type and made of
spheroidal graphite cast iron, with a dual-effect pneumatic actuator, and the pipes are
made from weld carbon steel and treated on the outside with primer and a coat of paint.
Control unit of the running and filter-washing operations including timer,
electromechanical programmer, water-powered stager for opening and closing the valves. The
water supply intake is supplied directly from the stretch of incoming piping equipped with
on-off valve and cartridge filter. From the 180 model up, the valve is pneumatic only; a
25 liter air compressor with a 1.1 kW single-phase 220 V - 50 Hz motor can be supplied on
request.
Choosing the "FIC" filter.
The choice of the FIC filter depends on the characteristics
of the water and what it is due to be used for. The higher rates of flow may be set up for
the function of "dechlorinating" water which has undergone a break-point
chlorination pretreatment with contact and mechanical filtering (FIM or FID filters),
which does not contain substances which must be absorbed.
The average rates of flow may be set up for the dechlorination of water which has
undergone a break-point chlorination pretreatment with intermediate contact without
mechanical filtering, but with intermediate contact without mechanical filtering, but with
a content of suspended particles which is less than 10 mg/l of SiO2 and for the function
of absorbing prefiltered water. The lower rates of flow are set up for the function of
absorbing organic microscopic pollutant elements, suface-active agents, etc. of water
which also features slight turbidity (less than 10 SiO2). The organic substance content
must, nonetheless, be generality lower than 20 ppm.
The service life of the filter bed can be estimated on the basis of a complete analysis of
the water, highlighting the characteristics and quantity of the organic substances
present.
For those waters containing high values of organic substances, oils, grease, methane gas,
contact the technical department.
The standard version of the "FIC" filters involves the washing of the filter
with untreated water at the rates indicated in the table; lower rates may result in the
filter bed not being washed properly.
Where specifically requested, and where the operating condition so allow, the backwashing
may be performed using water which has already been filtered, with the thrust provided by
a purpose-built pump station which will receive permission from the unit controlling the
filter operating phases.
OPERATING DATA:
- Min/max. operating pressure: 2-5 bar
- Min/max. water temperature: 5-40 °C
- Supply voltage/frequency: 220/50 V/Hz
- Power absorbed: 20 Watt
- Compressed air : 5 bar
