Abrégé

The present invention is directed to methods and apparatus for screening a pulp suspension where the pulp suspension is directed to a screening space, where a part of the fibres in the pulp is screened using a drum-type rotor. The residual pulp suspension is then directed to a dilution space where it is mixed with recirculated pulp flow and the pulp suspension in the dilution space will be screened. Resulting preliminary reject flow is directed to a mixing space where it mixes with a dilution flow. The recirculated pulp flow is then directed back to the dilution space.

Classes IPC  ?

• D21D 5/02 - Épuration de la pâte
• B01D 29/88 - Filtres à éléments filtrants stationnaires pendant la filtration, p. ex. filtres à aspiration ou à pression, non couverts par les groupes Leurs éléments filtrants comportant des dispositifs d'alimentation ou d'évacuation
• B07B 1/20 - Tambours fixes à agitateurs intérieurs mobiles
• D21B 1/32 - Triturage par d'autres moyens de vieux papiers

Abrégé

An apparatus and a method for processing recycled material, comprising a first pulper (3) having an inlet (2) for receiving recycled material (1), a water inlet (26) for producing a mixture of water and particles of recycled material, a first rotor unit (R1) configured to slush recycled material and a first screen plate (18) connected to a first outlet (20) configured to extract a first portion of recycled material from the first pulper (3); a last pulper (8) having a reject washer configured to remove coarse rejected recycled material from the last pulper (8); and an upper channel (4) from the first pulper (3) to the last pulper (8), wherein the mixture of water and particles of recycled material is configured to flow over from the first pulper (3) to the last pulper (8). The apparatus comprises a of the last pulper (8) being lower than or at the same level as the first pulper (3); a lower channel (40) at the bottom of the first pulper (3) extending to the last pulper (8); and a gate (45) at the lower channel (40), configured to cause, when open, the mixture of water and particles of recycled material to flush to the last pulper (8).

Classes IPC  ?

• D21B 1/32 - Triturage par d'autres moyens de vieux papiers
• D21B 1/34 - Pétrissage ou mélangePulpeurs
• D21D 5/04 - Épurateurs plats

Abrégé

The present invention is directed to methods and apparatus for screening a pulp suspension where the pulp suspension is directed to a screening space, where a part of the fibres in the pulp is screened using a drum-type rotor. The residual pulp suspension is then directed to a dilution space where it is mixed with recirculated pulp flow and the pulp suspension in the dilution space will be screened. Resulting preliminary reject flow is directed to a mixing space where it mixes with a dilution flow. The recirculated pulp flow is then directed back to the dilution space.

Classes IPC  ?

• D21D 5/02 - Épuration de la pâte
• B01D 29/00 - Filtres à éléments filtrants stationnaires pendant la filtration, p. ex. filtres à aspiration ou à pression, non couverts par les groupes Leurs éléments filtrants

Abrégé

A rotor unit in a vessel containing a mixture of water and particles of recycled material, comprising a rotor unit body (19); a screen plate (18) installed to the vessel; a rotor (78) connected to the rotor unit body (19) and configured to rotate inside the vessel, comprising at least two wings (81) configured to slush recycled material in a rotating action and at least two foils (82) configured to clean the screen plate (18) by rotating above the screen plate (18); a space (89) around the rotor (78) defined by a rotor body (77); pipework (21) configured to bring diluting water from outside the vessel to the space (89) around the rotor (78); wherein the rotor body (77) defining the space (89) around the rotor (78) comprises an opening (76) allowing the diluting water to pass through the opening (76) towards the mixture of water and particles of recycled material. The opening (76) at the rotor body (77) is at the same level with the lower edge of the at least two wings (81) or the at least two foils (82), wherein the diluting water is allowed to pass through the opening (76) to the screen plate (18).

Classes IPC  ?

• D21B 1/32 - Triturage par d'autres moyens de vieux papiers
• D21B 1/34 - Pétrissage ou mélangePulpeurs
• D21D 5/04 - Épurateurs plats

Abrégé

An apparatus and a method for processing recycled material, comprising a first pulper (3) having an inlet (2) for receiving recycled material (1), a water inlet (26) for producing a mixture of water and particles of recycled material, a first rotor unit (R1) configured to slush recycled material and a first screen plate (18) connected to a first outlet (20) configured to extract a first portion of recycled material from the first pulper (3); a last pulper (8) having a reject washer configured to remove coarse rejected recycled material from the last pulper (8); and an upper channel (4) from the first pulper (3) to the last pulper (8), wherein the mixture of water and particles of recycled material is configured to flow over from the first pulper (3) to the last pulper (8). The apparatus comprises a bottom of the last pulper (8) being lower than or at the same level as the first pulper (3); a lower channel (40) at the bottom of the first pulper (3) extending to the last pulper (8); and a gate (45) at the lower channel (40), configured to cause, when open, the mixture of water and particles of recycled material to flush to the last pulper (8).

Classes IPC  ?

• D21B 1/32 - Triturage par d'autres moyens de vieux papiers
• D21B 1/34 - Pétrissage ou mélangePulpeurs
• D21D 5/04 - Épurateurs plats