A rotary disc filter includes one or more filter discs secured to a rotary drum and include a series of circumferentially spaced backwash guides disposed in the filter disc. During backwashing, the backwash guides function to engage a mixture of backwash and suspended solids and guide or direct the mixture to a sludge trough disposed in the disc filter. The backwash guides generally assure that a greater percentage of the backwash and suspended solids mixture end up in the solids trough.

A rotary disc filter includes one or more filter discs secured to a rotary drum and include a series of circumferentially spaced backwash guides disposed in the filter disc. During backwashing, the backwash guides function to engage a mixture of backwash and suspended solids and guide or direct the mixture to a sludge trough disposed in the disc filter. The backwash guides generally assure that a greater percentage of the backwash and suspended solids mixture end up in the solids trough.

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.

A filter element for use in a filter disc, wherein a plurality of filter elements are arranged on a rotor shaft in a manner allowing liquid communication between the inside of the filter elements and the inside of the rotor shaft. The filter element has at least one passage in an edge structure for liquid communication between the inside of adjacent filter elements when the filter elements are assembled forming a filter disc. The passage has different passage area along the edge structure.

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.

The present invention relates to a filtering panel (100) for a disk filter and a disk filter for water purification, comprising a metal filter cloth (16, 116) such as a stainless steel filter cloth, pre-tensioned in both warp and weft directions and fastened to a frame (10, 110) comprising a peripheral portion (11, 111), which is integral with an inner grillwork (12) and which divides the inner area of the peripheral portion (11, 111) into fields (15, 115). The frame (10, 110) comprises a plastic material reinforced with glass fibers or carbon fibres such as polypropylene loaded with fibreglass in an amount of at least 20 weight percent. Each field of the grillwork (12, 112) has an area not exceeding 10% of the inner area of the peripheral portion (11, 111). The pre-tensioning of the filter cloth (16, 116) in both directions is from at least 20% of the yield stress of the cloth (16, 116). Further the present invention relates to a disk filter comprising said filtering panels (100) and method of making said filtering panel (100).

The present invention relates to a filtering panel (100) for a disk filter and a disk filter for water purification, comprising a metal filter cloth (16, 116) such as a stainless steel filter cloth, pre-tensioned in both warp and weft directions and fastened to a frame (10, 110) comprising a peripheral portion (11, 111), which is integral with an inner grillwork (12) and which divides the inner area of the peripheral portion (11, 111) into fields (15, 115). The frame (10, 110) comprises a plastic material reinforced with glass fibers or carbon fibres such as polypropylene loaded with fibreglass in an amount of at least 20 weight percent. Each field of the grillwork (12, 112) has an area not exceeding 10% of the inner area of the peripheral portion (11, 111). The pre-tensioning of the filter cloth (16, 116) in both directions is from at least 20% of the yield stress of the cloth (16, 116). Further the present invention relates to a disk filter comprising said filtering panels (100) and method of making said filtering panel (100).

The invention relates to an arrangement for detecting a damage of a filter fabric (8) of a disc filter (1) at a disc filter unit comprising disc filters. The arrangement comprises a measurement bar (20) comprising two or more microphones (21), a store (45) including stored sound samples, at least one alarming means and a processing arrange-ment (43) for analyzing online sound or sound samples captured by the microphones (21). The processing arrangement (43) is connected to the microphones (21), the store (45) and the at least one alarming means. The invention also relates to a method for detecting a damage of a filter fabric (8) of a disc filter (1) at a disc filter unit.

The invention relates to an arrangement for detecting a damage of a filter fabric (8) of a disc filter (1) at a disc filter unit comprising disc filters. The arrangement comprises a measurement bar (20) comprising two or more microphones (21), a store (45) including stored sound samples, at least one alarming means and a processing arrange-ment (43) for analyzing online sound or sound samples captured by the microphones (21). The processing arrangement (43) is connected to the microphones (21), the store (45) and the at least one alarming means. The invention also relates to a method for detecting a damage of a filter fabric (8) of a disc filter (1) at a disc filter unit.