Filtrations of various kinds result in filter cakes not being able to form completely in the turbidity channel (in the inlet area of the filter plates). While in other applications, e.g. fully automatic filter presses, a fixed filter cake in the turbidity channel is not desired. If, after filtration, a liquid suspension remains in the turbidity channel without core blowing, it leaks out when the plate package is opened, causing serious problems. Dirty filter cloths or deposits on the lower edge of the filter plates are only a few of the undesirable effects. This results in poor filtration results and high mechanical loads for the filter press.

FUNCTIONALITY CORE BLOWING

Compressed air is blown into the turbidity channel via a valve mounted on the movable pressure plate of the filter press before the filter chambers are opened. Compressed air flows through the pressure plate towards the head plate. Via a return line, the suspension-air mixture in the turbidity channel is returned to the storage tank and discharged. The compressed air requirement depends on the respective process and the size of the filter press. The decisive volume of the turbidity channel is between approx. 2L and approx. 200L.

Factors that influence how effective this process are:

• • Diameter of the suspension channel

• • Length of filter press equipment

• • Suspension viscosity

• • Available air pressure

• • Blow-out time

CORE RINSING

If, during filtration in the filter press, the suspension in the turbidity channel, which tends to sedimentation, compresses to a paste-like mass, for example, this cannot be squeezed out by core blowing alone. This problem is especially present with membrane filter presses. Dirty filter cloths or deposits on the lower edge and core bore of the filter plates leading to blockage, are only some of the undesirable consequences of these effects. After feeding is completed, operators can remove this sediment by rinsing the core.

FUNCTIONALITY CORE RINSING

During core rinsing, the rinse medium is introduced into the turbidity channel via a valve mounted on the movable pressure plate of the filter press. The rinse medium, mostly water, flows through the turbidity channel and absorbs the solids deposited there. Via a return line, the rinse medium is returned, for example, to a slurry storage tank. Afterwards only water remains in the turbidity channel. This is blown out relatively simply by compressed air using core blowing.