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Belt Discharge |
Precoat Discharge |
Roller Discharge |
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Scraper Discharge |
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Rotary vacuum filters type FTV with cake discharge
by blowback, belt, string, roll, precoat.
Manufactured in plastic, PRFG, completely metallic
with filtering surfaces from 0.5 to 60 sqm. Special
application for yeast filtration.
The rotary drum vacuum filters are composed by a
horizontal cylindrical drum divided into sections
connected by means of pipes, to a distribution
valve. The drum, covered by a filtering cloth in in
polypropilene or other synthetic material lying on
drainage grids manufactured by in polypropilene or
different materials, rotates, at variable speed,
partially immerged in a tank equipped with agitator
in order to maintain in supension the slurry to be
filtered. During rotation the drum is divided in
four separate areas by means of the bridges foreseen
inside the valve, that are : filtration area
corresponding to the submerged part of the drum,
washing area, drying area and cake discharge area.
Cake discharge is carried out in different manners
according to the cake characteristic; the filtrate
and drawn air are separated in filtrate receiver;
the liquid is sucked by an extraction pump or
discharged by a barometric column system while air
is drawn out by the vaccum pump.
The cake is lifted off the cloth by compressed air
blowing at low pressure into the discharge section.
The cake is collected by knife, slides on it and
falls into a belt or screw conveyor.
This type of filter is used in the treatments of
slurries with a high percentage of solid content and
a good permeability with cakes 3-4 mm. thick at
least.
Operation:
Precoating the entire surface of the drum up to a
thickness of 100 mm of Diatomaceous Earth, or other
filter aid.
Filtration of the liquid across the precoat, on the
surface of which the solide to be separated are
deposited.
Removal of cake, at each turn of the drum, by a
knife which moves forward automatically and
micrometrically.
The precoat filter is mainly used for :
filtration of liquids with the aim of obtaining
clear filtrates.
filtration of liquids containing highly obstructive
solids.
In the discharge area the cake is compressed by a
roll parallel to the drum having same length as the
drum, smaller diameter and rotating at the same
peripherical speed.
The cake leaves the surface of the drum and adheres
to that of the roll. It finally detaches from this
latter with the help of a knife and falls into a
belt or screw conveyor.
This type of filter is used when cakes no
thicker than 2 mm are formed and which, from
laboratory tests appear to adhere, better to the
roller (usually rubbelined) than to the filter
cloath.
The filtering cloth, as a continuous belt, is
stretched between the drum and a series of rollers.
A regulation system continuously centers the cloth
over the drum and on the roller while rotating.
After filtration, the cloth detaches itself from the
drum and thus the cakes falls by gravity into a belt
or screw conveyor.
After spray washing with a solution at high
pressure, the cloth wraps itself once again around
the drum, and is ready for filtration.
This type of filter is used in the treatment of
slurries which clog the cloth due to crystallization
or deposits and which therefore require a continuous
washing of the same.
A series of strings are stretched over the filtering
cloth on the surface of the drum and between the
drum and the two rollers.
After filtration the strings detach the cake from
the surface of the drum thus making it fall by
gravity into a belt or screw conveyor.
This filter is used for filtering slurries which
give rise to fibrous cake that will not be cut
by the strings.
Hyflow single cell rotary drum vacuum filter type
FTV / B
The hyflow FTV/B is a compact rotary drum vacuum
filter with blow back discharge completely
manufactured in high quality steel in accordance
with customer and process requirements. This rugged
filter of very simple design and very accurate
construction minimize the maintenance problems and
offers operating & performance results not found
within the scope of conventional filters.
Some of the relevant characteristic of FTV/B filter,
as shown in the sketches are listed below :
