The present invention relates to a blade for a disc refiner intended for refining lignocellulosic material, the blade (10) comprising a surface (1) delimited by an inner circumference (11) and an outer circumference (12), a refiner zone (2) on the surface (1) for refining lignocellulosic material, a blank zone (3) on the surface (1), wherein the refiner zone (2) is arranged closer to the inner circumference (11) than the blank zone (3), the blade (10) further comprising a separation groove (4) that is arranged between the refiner zone (2) and the blank zone (3), and at least one connecting groove (5) that connects the separation groove (4) to the outer circumference (12) of the blade (10) across the blank zone (3).

The invention also relates to a blade pair and to a refiner comprising at least one blade.

The present invention relates to a blade for a disc refiner intended for refining lignocellulosic material, the blade (10) comprising a surface (1) delimited by an inner circumference (11) and an outer circumference (12), a refiner zone (2) on the surface (1) for refining lignocellulosic material, a blank zone (3) on the surface (1), wherein the refiner zone (2) is arranged closer to the inner circumference (11) than the blank zone (3), the blade (10) further comprising a separation groove (4) that is arranged between the refiner zone (2) and the blank zone (3), and at least one connecting groove (5) that connects the separation groove (4) to the outer circumference (12) of the blade (10) across the blank zone (3).

The invention also relates to a blade pair and to a refiner comprising at least one blade.

There is disclosed a refiner segment (10) adapted to be attached to a refiner disc (30) in a refiner (100) of lignocellulosic material, said refiner segment (10) being provided with a plurality of spaced apart bars (20,) extending in a direction from an inner periphery (10a) of said refiner segment (10) towards an outer periphery (10b) of said refiner segment (10), where each pair of adjacent bars (20κ; 20K+I) bounds a corresponding intermediate area (22) on said refiner segment (10). The refiner segment (10) comprises at least one intermediate area (22) that comprises a channel region (23) and a ridge region (24), said channel region (23) connecting at a first side (23b) to said ridge region (24) and extending deeper into said refiner segment (10) than said ridge region (24) in order to create an intermediate area (22) having a cross-section with a varying depth profile. Also disclosed are a refiner disc comprising such refiner segments and a refiner comprising a refiner disc comprising said refiner segments.

A refiner disc including: a refining zone on a front face of the disc; refining bars in the refining zone; and grooves between the bars, wherein each of the grooves include a rotational inducement element arranged on at least one sidewall of the groove and the rotational inducement element is configured to impart at helical flow of feed material flowing through the groove.

The proposed technology provides refiner segment pair comprising a first segment (30) and a second segment (31), said first segment (30) being configured to be used with a rotor disc for a refiner of lignocellulosic material and said second segment being configured to be used with a stator disc for said refiner of lignocellulosic material, said first and second refining segments (30; 31) comprising protruding structures (40) for grinding of said lignocellulosic material. The height of the protruding structures (40) on said first refining segment (30) is at least three times larger than the height of the protruding structures (40) on said second refiner segment (31). The proposed technology also provides a refiner comprising such a refiner segment pair and the use of a refiner segment pair (30; 31) in a refiner (1) for refining lignocellulosic material.

A refiner segment for refining lignocellulosic material, has a surface including a plurality of bars extending along a direction between an inner periphery of the refiner segment and an outer periphery of the refiner segment, and a plurality of dams, each of the plurality of dams extending between a corresponding pair of adjacent bars among the plurality of bars, wherein at least one of the plurality of dams is a three-dimensionally extending body including three sides, the three-dimensionally extending body extends between the corresponding pair of adjacent bars and includes a curved side, forming one of the three sides, facing the inner periphery of the refiner segment, the curved side having a concave curvature with regard to the inner periphery to thereby form a rounded section in an area defined by the at least one of the plurality of dams and the corresponding pair of adjacent bars.

A refining member comprising a refining body with a refining surface comprising first and second refiner bars separated by first and second refiner grooves, respectively. The first refiner bars extend from a radially inward position to a first radially outward position. The second refiner bars extend to a second radially outward position that is nearer to an outermost part of the refining body than the first radially outward position. The second refiner bars have a longitudinal length from about 0.6 cm to about 10 cm. The first and second refiner bars have a respective first and second maximum height extending upward from a floor of a respective, adjacent first or second refiner groove. The second maximum height is at least 0.35 mm less than the first maximum height. The first refiner bars are adapted to refine wood fibers and the second refiner bars are adapted to break up fiber bundles.

Disclosed is a refiner filling piece for a refiner having a rotor that rotates about an axis of rotation and cooperates with a stator to mechanically treat a pulp containing cellulosic fibers. The refiner filling piece is mountable to the rotor or the stator. The refiner filling piece comprises a base and a plurality of spaced-apart refiner bars, each refiner bar being defined by a bar length and a bar height. At least some of the refiner bars have a surface coated with a variable coating. The surface having the variable coating may be the leading surface of the bar.

A blade element (1) for a refiner for refining fibrous material comprises a refining surface (3) provided with blade bars (8, 10) and blade grooves (9, 11) there-between. The blade bars (8, 10) have side walls (8, 8) facing away from one another. The side walls (8, 8) of the at least one blade bar (8) comprise on both of its side walls (8, 8) steps (14, 14) which extend at least partly in the transversal direction relative to the side walls (8, 8) of the blade bar (8) and away from one another.

A blade element pair (20) for a refiner (1, 2, 3) is intended for refining fibrous material. Each blade element (5, 5, 8, 8) of the blade element pair (20) has a refining surface (6, 9) with blade bars (16, 18) and blade grooves (17, 19) extending along the blade element (5, 5, 8, 8), and openings (14,15) extending through the blade element (5, 5, 8, 8). The openings (14, 15) in one of the blade elements (5, 5, 8, 8) is at different axial (A) or radial (R) positions from the openings (14,15) in the other blade element (5, 5, 8, 8) when the blade elements (5, 5, 8, 8) of the blade element pair (20) are set substantially opposite to each other.