Technical Description
A filter cake is periodically filtered onto a set of horizontal, slightly conical filter plates - arranged one above inside a pressure vessel - as a result of the pressure differential prevailing on the upper plate side. The filtrate pas-ses over the plate surface to a central manifold from where it leaves the pressure vessel. Following subsequent treatment, e.g. washing, extraction, steaming, blow-out or hot drying, the filter cake is normally shaken from the set of plates by means of defined oscillations whereupon it drops through a discharge flap.
The filter elements consist of cone-shaped, metal plates lined in an open
meshed supporting fabric and covered with a suitable filter cloth.
To the centre of the plates is welded a hub, geared on both sides, with 4 location holes for the tie rods that are required for bracing the set of plates. The suspension to be filtered is either delivered from below under con-stant pressure or at a constant volumetric rate of flow. The end of filtration may be defined by setting a maximum pressure, a minimum filtration rate or a specific time.
Before the actual clear mother filtrate is discharged, the turbid filtrate can be circulated until clear flow is attained.
Resulting from the prevailing pressure differential, the filtrate flows through the building filter cake and filter cloth whereupon it passes across the open-meshed supporting fabric to the centre of the hub. From here it is fed into the central filtrate pipe (fixed to the set of plates) and is then - in most cases - discharged up through a coaxial immersed pipe. Depending on the process-related requirements, the filter cake may undergo further treat-ment after the main 
filtration cycle, e.g. washing, extraction, blow-out, stea-ming or hot drying.
The entire set of plates is inflexibly joined to a drive head that projects on either side and contains 2 opposing unbalance motors. In relation to the pressure vessel, it is flexibly supported at the upper central flange. The unbalance motors generate defined oscillations in the set of plates
This cracks open the filter cake, pushes it outward over the rim of the plates and discharges through the vessel cone. No residue is left on the plates. With the set of plates constantly vibrating, the cake is discharged through a discharge flap at the base of the vessel cone. Additional equip-ment can be used for heel filtration.