Vibration cake discharge

The OMD leaf filter (Stella Meta Filters) is a vertical leaf filter with a mbber diaphragm suspended between the leaves. The cake that forms on the leaves eventually reaches the diaphragm at which point pump pressure is used to inflate the diaphragm and compress the cake. The cake discharge is by vibration. 

Step 5. Cake Discharge - At this point the air pressure is released, the cake outlet is opened and the leaf stack is vibrated to discharge the cake. The cake outlet opening must be interlocked with a pressure sensor to avoid opening under pressure. On some filters the cloth or mesh screen may be backwashed with water after cake discharge to dislodge and remove any cake residue that adhered to the medium. 

Automatic cake discharge by design of automatic filter-plates shifting and filter-cloth vibrating mechanism... 

Another available design aUows discharge of the cake by vibration of the circular plates, which are slightly conical, sloping downward toward the outside of the plates. This design aUows higher pressures to be used as there are no rotating seals necessary. 

Vertical filters are not convenient for the removal of dry cake, although they can be used in this service if they have a bottom that can be retracted to permit the cake to fall into a bin or hopper below. They are adapted rather to wet-sohds discharge, a process that may be assisted by leaf vibration, air or steam sparging of a filter full of water, sluicing h om fixed, oscillating, or traveling nozzles, and blowback. 

L. Vibrational conveyance. This is referred as the vibratory centrifuge. A relatively bign frequency force is superimposed on the rotating assembly. This can be either in-line with the axis of rotation or torsional, around the drivesbaft. In either case, the cake under inertial force from the vibration is partly fluidized and propelled down the screen under a somewhat steady pace toward the large end, where it is discharged. 

Shakers that subject the plate to vibrations and assist in discharging the cake. 

Vibrator type — a tray in which the bottom and one end curves up gently to be level with the top edges of the sides. An attached vibrator breaks up the solid and shakes it over die curved end of the tray to a discharge conveyor. Cakes may be up to 3 inches thick... 

Because these filters (Fig. 12) are made so that the leaves can be rolled from the filter quickly, they can be easily inspected for tears in the septum, leaks around the edges of the screens or around the gaskets in the manifold, improper precoating, and so forth. If the cake is blown dry in the filter before the leaves are removed from the filter shell, the cake will usually remain on the leaves so that it can be discharged either manually or by means of a vibrator. Hydraulic capacity of the leaves is usually not a problem, because their size need not be excessively large for the larger areas. 

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