Page 55 - Bluebook Sereco english

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Compactors

• CTG
• CTGC

The screened material retained by the screens of the civ- are practically three, as much as the options sheets are.
il or industrial wastewater treatment plants often have For the selection of the most suitable compactor mod-
the disadvantage of containing a high percentage of el it is necessary to identify the option sheet regarding
water and/or faecal material with consequent increase the case being examined and the type of compactor
of the storage and transport costs. The compactors solve meeting the nominal flow of the plant (m /day), accord-
3
this problem by washing, compacting and dewatering ing to the filtering gap of the upstream screen feeding
the screened material. The most used compactors for the compactor.
those applications are the hydraulic and screw types. The Obviously the values are theoretic and refer to mid-load
dedicated sheets give a description of the characteris- civil sewages as these sheets have the only aim at facil-
tics and advantages for each of them. To facilitate a itating the compactor model identification.
prompt selection of the size more suitable for the spe- With regard to the CTGC screw compactor, the stan-
cific case, the sheets include, in addition to the nominal dard length is such as to ensure an optimum com-
flow of each model, also three useful option tables. The paction of the screened material, keeping high sturdi-
values of those tables are based on the fact that in most ness and stiffening of the screw. Compactors with
cases the compactors are located downstream the coarse screw lengths exceeding the standard value can be sup-
or fine screens for the compaction of the material plied to meet any distance requirements: however if the
screened by them. Often it occurs that the compactor is discharge distance is considerable, it is recommended
connected with a conveyor which collects and transports to use simple conveyors for the transport and standard
the materiel screened by several screens. The quantity compactors for the compaction.
of screened material depends, in this case, on the num- This way all the sturdiness and stiffening characteris-
ber of screens and their filtration gap. tics of the screw will remain unchanged.
Typical applications are: Any compactors can be made in stainless steel.
- compactor connected with coarse screen only, According to its direct experience and considering the
- compactor connected with fine screen only, where aggressive environmental conditions in which the com-
there is no coarse screening, pactor should operate, SERECO would recommend
- compactor connected with the coarse and fine screens to always select stainless steel compactors. The high-
at the same time, er initial cost will be amortized in a very few years,
- compactor connected with fine screen, where an thanks to the reduced maintenance expenses. For the
upstream coarse screening is serviced by separate com- only screw of the CTGC compactor, we would recom-
pactor. mend the standard material (carbon steel adequately
It can be easily understood that in the second case the heat treated), as it has a high hardness & strength on
screened material arriving to the compactor is the same the surface and toughness in the middle.
as that of the third case as the fine screen has to retain We wish to point out that the compaction process can
also the matters of greater size, retained in the third be also carried out directly by special screens, such as
case by the coarse screen. Therefore the possible cases the screw filters FC, FCS and FSS.