A device for filtering a stream of water in a channel (2), includes: a wall (6) adapted to be mounted in the channel and including a through-opening, a filter member (10) mounted on the wall opposite the through-opening and including a filter surface projecting relative to the wall, the filter surface having a larger area than would have a flat filter surface fitted in the through-opening, the filter member including retaining members face to face with the filter surface for retaining the bodies that do not pass through the surface, a suction device disposed facing the retaining members, and elements for driving the filter member and/or the suction device in a relative movement of one in relation to the other such that the suction device is successively brought face to face with each retaining member.

According to an example aspect of the present invention, there is provided, an apparatus and a method for treating mixtures of liquids and solids. The apparatus comprises a casing and a rotor mounted inside the casing and having an inner volume delineated by an outer surface. The outer surface is provided with flow connections to the inner volume and configured to be rotated within the casing. The casing and the rotor are set in a vertical position.

According to an example aspect of the present invention, there is provided, an apparatus and a method for treating mixtures of liquids and solids. The apparatus comprises a casing and a rotor mounted inside the casing and having an inner volume delineated by an outer surface. The outer surface is provided with flow connections to the inner volume and configured to be rotated within the casing. The casing and the rotor are set in a vertical position.

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).

A centrifugal filtering device includes a centrifugal drum and a rotary filter. The centrifugal drum has a receiving space for accommodating the source fluid. The rotary filter rotatably mounted in the receiving space includes a filter body and a filtrate discharge pipe. The filter body includes a filter cartridge defining a filtrate-collecting space. The filtrate discharge pipe connecting the filter body is communicative in space with the filtrate-collecting space. By rotating at least one of the centrifugal drum and the rotary filter, the source fluid is driven to generate a vortex by a centrifugal force. The centrifugal force drives the source fluid to form a heavy-phase fluid hitting the centrifugal drum and a light-phase fluid approaching the filter cartridge. The light-phase fluid passes the filter cartridge and then reaches the filtrate-collecting space as a filtrate, and the filtrate is exhausted via the filtrate discharge pipe of the centrifugal filtering device.

A centrifugal filtering device includes a centrifugal drum and a rotary filter. The centrifugal drum has a receiving space for accommodating the source fluid. The rotary filter rotatably mounted in the receiving space includes a filter body and a filtrate discharge pipe. The filter body includes a filter cartridge defining a filtrate-collecting space. The filtrate discharge pipe connecting the filter body is communicative in space with the filtrate-collecting space. By rotating at least one of the centrifugal drum and the rotary filter, the source fluid is driven to generate a vortex by a centrifugal force. The centrifugal force drives the source fluid to form a heavy-phase fluid hitting the centrifugal drum and a light-phase fluid approaching the filter cartridge. The light-phase fluid passes the filter cartridge and then reaches the filtrate-collecting space as a filtrate, and the filtrate is exhausted via the filtrate discharge pipe of the centrifugal filtering device.

A double-action pusher centrifuge separates a mixture into solid cake and liquid. The pusher centrifuge includes a screen drum rotatable about an axis and in which a pusher base device is arranged to be movable along the axis of rotation. The solid cake is displaced by an outer ring region of the pusher base device. A plurality of axial passage openings are disposed in the outer ring region and connect front and rear regions of the screen drum. A feed unit is arranged at an inflow disk such that the mixture can be introduced via the feed unit and the inflow disk into empty space on the screen drum on displacement of the solid cake. An inflow gap applies the mixture into the empty space, and is between an inflow edge of the inflow disk and a pusher base plate of the pusher base device with an inflow region.

According to various aspects and embodiments, a system and method for two-stage filtration is provided. The system includes an inlet fluidly connectable with wastewater, a first stage filter assembly that is fluidly connectable with the inlet and has a rotary drum with a filter surface configured for radially inward fluid flow, a second stage filter assembly that is fluidly connectable with the first stage filter and has a plurality of filter discs configured for radially outward fluid flow, and an outlet fluidly connectable with filtrate generated by the second stage disc filter assembly.

According to various aspects and embodiments, a system and method for two-stage filtration is provided. The system includes an inlet fluidly connectable with wastewater, a first stage filter assembly that is fluidly connectable with the inlet and has a rotary drum with a filter surface configured for radially inward fluid flow, a second stage filter assembly that is fluidly connectable with the first stage filter and has a plurality of filter discs configured for radially outward fluid flow, and an outlet fluidly connectable with filtrate generated by the second stage disc filter assembly.