Apparatus for filtering liquids

An apparatus for filtering liquids, such as fiber pulp suspensions or polluted water, comprising:

• at least two annular hollow filter discs adapted to be filtered and arranged substantially transverse to an axis extending centrally through the filter discs, each disc having two annular opposed walls, at least one of which is pervious by liquid and covered with filter material, the opposed walls having radially inner and outer ends;
• wall means connected to the annular opposed walls and forming a filtrate chamber, which extends centrally through the hollow discs and which communicates with the interior of the latter, the annular opposed walls of each filter disc being solely attached to each other at their outer ends, whereas they are spaced from each other at their inner ends, such that an annular opening is defined between the interior of each filter disc and the filtrate chamber;
• means for creating a pressure difference between the body of liquid to be filtered and the interior of the hollow filter discs, such that a fine fraction of the liquid is forced through the filter material into the hollow filter discs and passed therefrom into the filtrate chamber during operation;
• fine fraction discharge means for discharging fine fraction from the filtrate chamber;
• spray nozzle means for spraying a cleansing fluid against the filter material for cleaning the filter material, the spray nozzle means extending from the filtrate chamber through the annular opening of each filter disc into the interior of each filter disc;
• means for providing relative movement between the filter material and spray nozzle means in the circumferential direction of the filter discs;
• and
• at least one axially extending reinforcement beam attached to the walls of the filter discs at the outer ends of the filter discs.