A filtration filter comprises a porous film including a central film portion having a plurality of through holes and an outer edge portion adjacent to the central film portion. The porous film portion lies in a flat plane in the absence of a force being applied to the central portion of the central film portion. A frame holds the outer edge portion of the porous film in such a manner that when a force is applied to the central film portion in a first direction, the central film portion moves in the first direction relative to the flat plane and the outer edge portion moves in a second direction, opposite to the first direction, relative to the flat plane. In this way stresses applied to the porous film during a filtering operation are reduced.

A pressurizing centrifugal dehydrator for removing moisture includes: an inner basket into which slurry is introduced; an outer basket surrounding the inner basket; a pressurization chamber disposed in the outer basket; and a gas supplying portion for supplying gas into the pressurization chamber, wherein the gas supplied to the pressurization chamber is ejected from the pressurization chamber toward a dehydration product positioned between the outer basket and the pressurization chamber.

A pressurizing centrifugal dehydrator for removing moisture includes: an inner basket into which slurry is introduced; an outer basket surrounding the inner basket; a pressurization chamber disposed in the outer basket; and a gas supplying portion for supplying gas into the pressurization chamber, wherein the gas supplied to the pressurization chamber is ejected from the pressurization chamber toward a dehydration product positioned between the outer basket and the pressurization chamber.

A pressurizing centrifugal dehydrator for removing moisture includes: an inner basket into which slurry is introduced; an outer basket surrounding the inner basket; a pressurization chamber disposed in the outer basket; and a gas supplying portion for supplying gas into the pressurization chamber, wherein the gas supplied to the pressurization chamber is ejected from the pressurization chamber toward a dehydration product positioned between the outer basket and the pressurization chamber.

A pressurizing centrifugal dehydrator for removing moisture includes: an inner basket into which slurry is introduced; an outer basket surrounding the inner basket; a pressurization chamber disposed in the outer basket; and a gas supplying portion for supplying gas into the pressurization chamber, wherein the gas supplied to the pressurization chamber is ejected from the pressurization chamber toward a dehydration product positioned between the outer basket and the pressurization chamber.

A pulp-filter arrangement (1) comprises a rotatable drum (10) and a non-rotating valve arrangement (30). The rotatable drum (10) has a cylindrical water-permeable pulp-supporting shell (14), a plurality of drain pipes (16) and a rotating hollow shaft (18). The plurality of drainpipes (16) connects the rotating hollow shaft (18) with a collecting channel (22) situated radially directly inside the cylindrical water-permeable pulp-supporting shell (14). The non-rotating valve arrangement (30) is disposed within the rotating hollow shaft (18) for sealing off the rotating hollow shaft (18) from a radially inner outlet (24) of the drain pipes (16) when respective radially inner outlet (24) is situated within a sealed zone. The non-rotating valve arrangement (30) is further arranged to, in a transition zone immediately following the sealed zone, open a throttled passage between the rotating hollow shaft (18) and the radially inner outlet (24).

A pulp-filter arrangement (1) comprises a rotatable drum (10) and a non-rotating valve arrangement (30). The rotatable drum (10) has a cylindrical water-permeable pulp-supporting shell (14), a plurality of drain pipes (16) and a rotating hollow shaft (18). The plurality of drainpipes (16) connects the rotating hollow shaft (18) with a collecting channel (22) situated radially directly inside the cylindrical water-permeable pulp-supporting shell (14). The non-rotating valve arrangement (30) is disposed within the rotating hollow shaft (18) for sealing off the rotating hollow shaft (18) from a radially inner outlet (24) of the drain pipes (16) when respective radially inner outlet (24) is situated within a sealed zone. The non-rotating valve arrangement (30) is further arranged to, in a transition zone immediately following the sealed zone, open a throttled passage between the rotating hollow shaft (18) and the radially inner outlet (24).

Water or wastewater filtration systems and processes have a filter tank having a floor and sidewall defining a filtration zone, an influent conduit, and an effluent conduit. One or more filtration members in the tank having filter media, and one or more cleaning members adjacent at least some portions of the filter media. Generating an effluent stream by generating a pressure differential across submerged portions of the filtration media, causing water in the influent to flow from outside to inside the submerged portions of the filter media. A prime mover rotates the filtration members. A blower and chamber for creating a reduced pressure condition in each of the cleaning members when they are non-submerged, the chamber receiving wet solids removed from non-submerged, wet solids-laden portions of the filter media by the non-submerged cleaning members subsequent to submerged, fouled portions of the filter media being rotated out of the filtration zone.

The invention relates to a filter panel (1) for a drum filter (2) which is used for filtering off solid particles from a liquid. The filter panel (1) comprises a first side (3) being adapted to be attached to a drum (4) of said drum filter (2), a second side (5) being adapted to receive a filter cloth (6), and a plurality of through holes (7) extending from said first side (3) to said second side (5), each hole (7) defining one or more side walls (8). The filter panel (1) is characterized in that at least one of said holes (7) comprises an inclined side wall (8). The invention also relates to a drum filter (2) for filtering liquid.

The invention relates to a filter panel (1) for a drum filter (2) which is used for filtering off solid particles from a liquid. The filter panel (1) comprises a first side (3) being adapted to be attached to a drum (4) of said drum filter (2), a second side (5) being adapted to receive a filter cloth (6), and a plurality of through holes (7) extending from said first side (3) to said second side (5), each hole (7) defining one or more side walls (8). The filter panel (1) is characterized in that at least one of said holes (7) comprises an inclined side wall (8). The invention also relates to a drum filter (2) for filtering liquid.