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.

A system (1) for refining lignocellulosic biomass material (A) comprising a presteaming bin (2), a dewatering device (3), a preheater (4), a defibrator (9) comprising at least one refining zone (14) wherein steam is generated during refining of said biomass material so that a pressure peak occurs, a blowpipe (19), and a first steam flow path (D) arranged to convey steam from said refining zone to said presteaming bin (2). The system further comprises a second steam flow path (E) arranged to convey steam from said refining zone to said presteaming bin, wherein said first and second steam flow paths are connected to the refining zone on opposite sides of the pressure peakin a biomass material transport direction, and wherein said first and second steam flow paths are separate from said blow pipe. The invention also relates to a process for refining lignocellulosic biomass material.

A system (1) for refining lignocellulosic biomass material (A) comprising a presteaming bin (2), a dewatering device (3), a preheater (4), a defibrator (9) comprising at least one refining zone (14) wherein steam is generated during refining of said biomass material so that a pressure peak occurs, a blowpipe (19), and a first steam flow path (D) arranged to convey steam from said refining zone to said presteaming bin (2). The system further comprises a second steam flow path (E) arranged to convey steam from said refining zone to said presteaming bin, wherein said first and second steam flow paths are connected to the refining zone on opposite sides of the pressure peakin a biomass material transport direction, and wherein said first and second steam flow paths are separate from said blow pipe. The invention also relates to a process for refining lignocellulosic biomass material.

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.

A blade segment (4, 4a, 4b, 8, 8a, 8b) for a refiner (1) for refining fibrous material has first (20) and second (21) end edges and first (22) and second (23) side edges, the first (22) and second (23) side edges extending between the first (20) and second (21) end edges. The segment has a refining surface (5, 9) with blade bars (27) and grooves (28) on the segment front surface (25). At least one opening (14, 15) at the side edge (22, 23) extends through the whole thickness of the segment body (24) and towards the opposite side edge (22, 23). A guide element projects from the segment background surface (26) at the side edge which provides a guide surface that intensifies the feed of the material to be refined through the opening to the refining surface of the blade segment into the refining chamber of the refiner.

A method for controlling a device for treating a fibrous material includes the steps of: providing that the device includes a housing in which at least a first treatment tool and a second treatment tool are arranged; mounting at least one of the first base plate and the second base plate in an axially movable manner in order to compensate for a wear of the first treatment profile and the second treatment profile; measuring a distance between the first base plate and the second base plate respectively of the first treatment tool and the second treatment tool of a treatment nip during an operation of the device; and selecting a value of a total power depending on the distance between the first base plate and the second base plate of the at least one treatment nip.

The present invention concerns a sensor device (1) comprising a transducer (3) adapted to generate a magnetic field (MF), the sensor device (1) is configured to measure a beating gap (G) between a first (5) and a second (7) refining disc of a refiner apparatus (9) and is configured to be mounted in the first refining disc (5), the sensor device (1) comprises a magnetic pole (13), a coil assembly (15) and a measuring head (11′), which measuring head (11′) is configured to be set in calibration position relative to the second refining disc (7) for calibration of the sensor device (1). The measuring head (11′) comprises an outer end (10′) made of a non-magnetic material configured to be positioned in abutment with the second refining disc (7) in a calibration sequence. The present invention also concerns a method of calibration of said sensor device (1).

A disperser-refiner plate segment includes a refining section disposed radially outward from a dispersion section. Teeth in the dispersion section have a height that exceeds a height of refining bars in the refining section.