A blade segment of a disc refiner for refining fibrous material has an inner circumference and an outer circumference as well as a first side edge and a second side edge which connect the inner circumference and the outer circumference. The side edges are curved, with one convex and the other concave. The segment has a refining surface with blade bars and grooves which define a pumping direction. The side edges of the blade segment curve in the vicinity of the inner circumference in the pumping direction, and in the vicinity of the outer circumference in a non-pumping direction.

A plate segment for refining an aqueously suspended fibrous material in a refining gap delimited by two treatment surfaces rotating relative to each other and formed by a plurality of the plate segment, includes: a basic body including: a plurality of elongate treatment elements which face the refining gap and run radially at least with one directional component; a plurality of grooves running between the plurality of elongate treatment elements, the plurality of grooves including a groove base; and a plurality of channels running at least with one directional component radially and at least approximately parallel to the refining gap, being at different distances from the refining gap and arranged in the basic body, and at least partially overlapping one of one another and with the groove base in a direction of rotation.

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 distance between the distal surface of said center plate and the surface of said second refining disc (12) is as small as possible without having their surfaces touching each other.

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 distance between the distal surface of said center plate and the surface of said second refining disc (12) is as small as possible without having their surfaces touching each other.

An assembly comprising an annular hub with a hub inner surface and a hub outer surface and a rotary third refining member having a central opening within a refining member inner surface. The refining member has at least two equally spaced apart member portions extending radially inwardly from the member inner surface, and the assembly includes a key for connecting the member portions to the hub. The assembly also include an annular cover plate with at least two radially extending spaced apart flanges, each flange overlying a member portion, and at least two spaced apart port plates, each port plate overlying a member portion side opposite the annular cover plate, the spaces between the at least two port plates defining ports from a first stock flow path to a second stock flow path.

An assembly comprising an annular hub with a hub inner surface and a hub outer surface and a rotary third refining member having a central opening within a refining member inner surface. The refining member has at least two equally spaced apart member portions extending radially inwardly from the member inner surface, and the assembly includes a key for connecting the member portions to the hub. The assembly also include an annular cover plate with at least two radially extending spaced apart flanges, each flange overlying a member portion, and at least two spaced apart port plates, each port plate overlying a member portion side opposite the annular cover plate, the spaces between the at least two port plates defining ports from a first stock flow path to a second stock flow path.

A processing plate (4, 12) for mechanically processing pulp. The plate has projecting parts (6, 7, 14, 15). The projecting parts (7, 15) comprise a radially inner part (28) having an inclined ascending wall (29) towards the outer periphery (23) of the plate and a radially outer part (30) having an inclined descending wall (31) towards the outer periphery (23) of the plate (4, 12). The inner and outer parts (28, 30) are radially coupled to each other by a ridge (32) along a coupling line (CL). The walls (29, 31) are mutually connected only partly so that they have in common only a crest section (40) of the ridge (32) which crest section (40) is less than a width of at least one of the wall (29) of the inner part (28) and the wall (31) of the outer part (30) at the coupling line (CL).

A processing plate (4, 12) for mechanically processing pulp. The plate has projecting parts (6, 7, 14, 15). The projecting parts (7, 15) comprise a radially inner part (28) having an inclined ascending wall (29) towards the outer periphery (23) of the plate and a radially outer part (30) having an inclined descending wall (31) towards the outer periphery (23) of the plate (4, 12). The inner and outer parts (28, 30) are radially coupled to each other by a ridge (32) along a coupling line (CL). The walls (29, 31) are mutually connected only partly so that they have in common only a crest section (40) of the ridge (32) which crest section (40) is less than a width of at least one of the wall (29) of the inner part (28) and the wall (31) of the outer part (30) at the coupling line (CL).

A blade element (4, 8) for a comminution device (1) to comminute fiber material has at least one comminution section (22) with comminution parts (20, 24, 25, 26) and free spaces (21) therebetween, and at least one feed section (23) extending at least partly in a longitudinal direction (X) of the blade element (4, 8), each feed section (23) intended to feed fiber material to the respective comminution section (22). The comminution parts have a first dimension (d20a, d20b, d20c, d24a, d24b, d24c) extending in a circumferential direction (C) of the blade element and a second dimension (e20a, e20b, e20c, e24a, e25a, e26a) extending in the longitudinal direction (X) of the blade element. At the same longitudinal (X) position in the blade element (4, 8) the first dimension of the comminution parts is arranged to increase in the circumferential direction (C) of the blade element toward the feed section.

Disclosed are a welding slag clearing device, a welding machine head and a welding system. The welding slag clearing device includes: a mounting frame; a slag crushing mechanism comprising a slag crushing wheel and an adjusting assembly, the slag crushing wheel is connected to the adjusting assembly, the adjusting assembly is connected to the mounting frame, and the adjusting assembly is configured to adjust a longitudinal distance of the slag crushing wheel relative to the mounting frame; and a welding slag recovery mechanism comprising a hollow recovery pipe and a connecting piece used for connecting the recovery pipe with the mounting frame, the recovery pipe is correspondingly arranged right behind the slag crushing mechanism in a transverse direction.