"Ecofilter" Filter Ecofilter is a stainless steel compact unit on wheels, equipped with all accessories required for best operating conditions. Due to original patent pending Padovan design, the filter plates assure an elevated drainage flow during filtration and precoating, besides a complete and accurate washing, even under the filtering cloth. The filtering elements are made of stainless sheet steel AISI 304 provided with drawn reliefs against which is placed the filtering cloth made of stainless steel AISI 316L with a 60 micron mesh, standard version. The most significant feature consists in the lack of the drainage grid, a cause of pollution. The upper support of filter plates' shaft is provided with a double seal ring with safety discharge to protect rotating parts. The lower support is easy accessible. Motorization for rotation of filter plates is equipped with hydraulic coupling. A very important factor for the formation of an even cake is to obtain a uniform distribution of liquid into the chamber. A special inlet flow distributor avoids vortexes and abnormal flows of liquid at both high and low outputs. After filtration operations the residual liquid in the chamber is drained by means of the main pump and filtered through an external auxiliary filter. This allows to empty the chamber completely and make the use of the filter independent from the association for the control of pressure vessels (ISPESL). The residual liquid is filtered in approximately 10-15 minutes. The auxiliary filter is provided with horizontal filter plates and is very easy to disassemble and wash. The filtration is done with Diatomaceous Earth. The cake is discharged from the filter as a paste by fast turning of the filter plates. The annular section between filter plates and cylindrical body is very large and so is the free space on the lower part. This allows to discharge easily the cake from filter plates and accumulate the cake on the bottom without immerging the lower filter plates. The cake is conveyed by means of rotating blades to a discharge door and collected in an external vat on wheels provided with the filter. For final washing, the filter elements are rotated and sprayed at the same time with water coming out from calibrated holes in a vertical manifold. Washing is performed in about 5 minutes with a consumption of approx. 30-50 litres of water per square meter of filtration surface. A noteworthy feature of the Ecofilter is that the position of washing manifold may be adjusted by turning the sprays in the most suitable direction; it may also be removed for cleaning without filtration chamber's opening. Waterproof switch-board according to CEI IP 55 standards with low voltage controls. Models from 5 to 60 m2. Precoating The filter is filled with water or clear liquid that flows in a closed circuit between inlet and outlet of filtration chamber by means of the main pump. The filter aid suspension is injected into the circuit and retained by the filter plates' cloths forming an even precoat. Filtration The liquid to be filtered is fed by the main pump adding a pre-set quantity of filter aid. The solid substances to separate and the filter aid are retained by the filter plates, thus forming an even and porous cake. Filtration of filtration cycle residues. During precoating in the filtration chamber, another precoat is formed in the auxiliary filter. The latter is used during filtration exclusively for the residues' filtration. The main pump is also used to feed this filter. Cake discharge and filter washing. The cakes are detached by rotating the filter elements and fall on the bottom of the chamber where they are removed through the door. After this operation, the filter plates are washed with water sprayed through the vertical manifold. The filter plates rotate during this operation so that all parts may be washed. The Ecofilter is used for clarifying and polishing filtration of turbid liquids containing low concentrations (0,5 - 5 g/l) of highly obstructive solids in suspension. Filter aids such as Diatomaceous Earth or Perlite are added in preset quantities to the turbid liquid to be filtered. The cake, a mix of filter aid and separated solid substances, maintains its porosity for a long time during filtration. The filter aid/solid ratio affects the increments of load loss through the cake and consequently total time of filtration cycle (see theoretical filtration diagram).