Page 167 - Bluebook Sereco english

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Sludge thickeners and dewaterers

• IFCC • NPF
• IFTP • NPF_MP
• IFD • NPF_HP
• ING

The sludge line in a civil or industrial sewage treatment initial gravity table, first drainage roller with big diam-
plant is important and has management costs that eter to treat also sludge difficult to be dewatered, nine
sometimes are the same as those for the water line. It smaller rollers with high pressure required to achieve
is therefore very important to be able to thicken the high performance in dried products at the outlet.
sludge before conveying it to the subsequent treatment Any belt press models can be supplied with a sludge
cycles and free it as much as possible from the water pre-reactor dimensioned from time to time to ensure
before the final disposal. a contact time between sludge and polyelectrolyte ade-
The range of SERECO products includes gravity quate for the obtainment of an optimum flocculation.
thickeners, dynamic thickeners and belt presses for the SERECO, which has been since long operating in
final dewatering. the treatment field, always aiming at solving any prob-
In particular, the gravity thickeners are with central lem and minimizing the management costs of the
(IFCC) or peripheral (IFTP) drive. plants, has decided to offer the sludge belt press dewa-
The dynamic rotating drum thickener (IFD) is generally tering system which currently is the technological prod-
used to reduce the water percentage in the sludge uct that, for the same sludge load, boats the lowest
before the putting into the belt presses for dewatering. energy consumption, the greatest operating reliability
Actually, the belt presses NPF_MP and NPF_HP types and a reduced ordinary maintenance that can be eas-
allow the sludge to contain high water percentages at ily carried out by the technicians entrusted with the
the inlet, nevertheless reaching high dry content at the plant maintenance, without resorting to expensive and
outlet. This is due to the presence of an initial gravity frequent shipments of the equipment to the manufac-
table, integral with the belt press, which carries out a turer. A comparison with the operation and mainte-
drastic reduction of the water percentage in the sludge nance costs for centrifuges, plate filter presses or oth-
before being submitted to the rollers pressure. er sludge dewatering system is even inconceivable.
The belt press NPF type offers instead the great advan- SERECO sludge line also comprises further machines
tage of the compactness and completely closed exe- that are not included in this section dedicated to thick-
cution which are a guarantee of hygiene and safety. eners and dewaterers only. In particular, the anaerobic
The NPF_MP and NPF_HP types are recommended for sludge digesters (DACS) and the sludge heat exchang-
the treatment of big quantities of sludge, with belt up ers (SCF) are present in the section dedicated to
to 3 m wide. digesters-gasometers-exchangers, and the polyelec-
The NPF_HP type is the leading model of our current trolyte preparation and dosing unit (PDP, PDPA) in the
production, with wide working area of the belts, huge section dedicated to dissolution groups.