Abstract: A refiner for refining of lignocellulosic material includes a rotor disc and a stator disc. The rotor disc includes a first refining segment that includes a plurality of first protruding structures for grinding of the lignocellulosic material. Each of the first protruding structures is defined by a first height. The stator disc is arranged opposite the rotor disc and includes a second refining segment that includes a plurality of second protruding structures for grinding of the lignocellulosic material. Each of the second protruding structures being defined by a second height. The first height is at least three times larger than the second height.

Abstract: A refining disc (6) in a defibrator (1) for refining fibrous material is provided with non-central openings (11) for allowing steam developed in the refining space (2) during refining to flow from the front side to the backside of the refining disc (6), where the front side is facing a second refining disc (5) and the backside is facing away from the second refining disc (5). The refining disc (6) also comprises a central hole (12) for allowing steam (8b) to flow from the backside to the front side at the rotational center of the refining disc (6), and escape from the defibrator (1) backwards through the feed screw (3a) without passing through the fibrous material (7) being refined in the refining space (2).

Abstract: The invention relates to a double disc pulp refiner (10) comprising a first refining disc (11) and a second refining disc (12), the first refining disc being arranged at a feed end of the refiner (10) where lignocellulosic material (M) is fed into the refiner (10) through inlet openings (16) in the first refining disc (11) and the second refining disc (12) being arranged coaxially, spaced apart from and opposed to the first refining disc (11), said first refining disc (11) being provided with at least one refining segment (13) for refining the lignocellulosic material (M) and a center plate (20)having a cross-sectional profile adapted such that when the center plate (20) is arranged on the first refining disc (11) in the refiner (10), the center plate (20) protrudes to a maximum height which is the same as, or higher than, a maximum height of the at least one refining segment (13) provided on the first refining disc (11), said double disc pulp refiner (10), wherein said maximum height is such that the distanc

Abstract: A refining disc (6) in a defibrator (1) for refining fibrous material is provided with non-central openings (11) for allowing steam developed in the refining space (2) during refining to flow from the front side to the backside of the refining disc (6), where the front side is facing a second refining disc (5) and the backside is facing away from the second refining disc (5). The refining disc (6) also comprises a central hole (12) for allowing steam (8b) to flow from the backside to the front side at the rotational center of the refining disc (6), and escape from the defibrator (1) backwards through the feed screw (3a) without passing through the fibrous material (7) being refined in the refining space (2).

Abstract: A blade element (12) for a refiner (10, 11) for refining fibrous material has an inner edge (13) and an outer edge (14) and first blade bars (18) and first blade grooves (19) therebetween, the first blade bars and the first blade grooves extending toward the outer edge of the blade element. At top surfaces of the first blade bars there are second blade bars (20) and second blade grooves (21) therebetween. At least some of the second blade bars (20) lying on an outer end portion (12b) of the blade element (12) have a width which is larger than a width of second blade bars (20) lying on an inner end portion (12a) of the blade element (12) and/or is increasing in direction toward the outer edge (14) of the blade element (12).

Abstract: A center plate for a rotor in a pulp refiner is described in which the center plate is provided with a plurality of first wings for directing pulp flowing onto the center portion of the center plate towards the periphery of the center plate, each of the first wings comprising an arc-shaped protrusion extending between a corresponding first point and a corresponding second point on the surface of the center plate, the first point being displaced from the center portion of the center plate and the second point being disposed further from said center portion of the center plate then the first point, the first wings having an arc shape that yields a larger pulp feeding angle then that of a circular arc intersecting the center portion of the center plate and ending in the same corresponding second point, and the second point of each of the first wings lies on the periphery of the center plate.

Abstract: A blade element (12) for a refiner (10, 11) for refining fibrous material comprises an inner edge (13) and an outer edge (14) and first blade bars (18) and first blade grooves (19) therebetween, the first blade bars and the first blade grooves extending toward the outer edge of the blade element. At top surfaces of the first blade bars there are second blade bars (20) and second blade grooves (21) therebetween. At least some of the second blade bars (20) lying on an outer end portion (12b) of the blade element (12) have a width which is larger than a width of second blade bars (20) lying on an inner end portion (12a) of the blade element (12) and/or is increasing in direction toward the outer edge (14) of the blade element (12).

Abstract: A center plate for a rotor in a pulp refiner is described in which the center plate is provided with a plurality of first wings for directing pulp flowing onto the center portion of the center plate towards the periphery of the center plate, each of the first wings comprising an arc-shaped protrusion extending between a corresponding first point and a corresponding second point on the surface of the center plate, the first point being displaced from the center portion of the center plate and the second point being disposed further from said center portion of the center plate then the first point, the first wings having an arc shape that yields a larger pulp feeding angle then that of a circular arc intersecting the center portion of the center plate and ending in the same corresponding second point, and the second point of each of the first wings lies on the periphery of the center plate.