Abstract: A special shape of bars on refining discs or plate segments of a rotating disc refiner is disclosed including a plurality of bars generally extending outwards towards the outer end of the disk across its surface, arranged in a single, two or more radial zones, the plurality of the bars within a zone being curved with the shape of a logarithmic spiral. Disc refiners including such refining discs are also disclosed.

Abstract: A special shape of bars on refining discs or plate segments (54) of a rotating disc refiner (10) is disclosed including a plurality of bars (76) generally extending outwards toward the outer end of the disk across its surface, arranged in a single, two or more radial zones (64, 66, 68), the plurality of the bars within a zone being curved with the shape of a logarithmic spiral. Disc refiners including such refining discs are also disclosed.

Abstract: A refiner plate segment for a refiner including opposed first and second refiner plates has radially inner and outer ends, multiple radially disposed bars, and grooves alternating with the bars. The base of at least one of the grooves has a variable base profile along the radial length of the base such that in at least one radial position between the inner and outer ends of the refiner plate segment, the base profile of the refiner plate segments of the first refiner plate has a low point and the base profile of the refiner plate segments of the second refiner plate has an oppositely disposed high point. The high point in the base profile forces lignocellulosic material carried on the second refiner plate onto the first refiner plate.

Abstract: A refiner plate for the face of a refiner disc comprising a plurality of refiner segments arranged side-by-side on the face of the disc to form a substantially annular refining region. Each refiner segment has a plurality bars and grooves for refining a lignocellulosic material and forming a path for receiving and transmitting steam generated during the refining process. A plurality of dams are disposed within the grooves to retard the movement of the lignocellulosic material. A partial height portion of each dam adjacent the trailing face of the bar provides a flow path for the steam.

Abstract: A refiner for refining lignocellulosic material having opposed, relatively rotating, rotor and stator refiner plates. The refiner plates each have radially inner and outer edges and an inlet zone extending radially outward from the inner edge. The inlet zone of each refiner plate has a radially inner portion and a radially outer portion. The inner portion of the rotor plate includes a plurality of breaker bars which curve in a direction which is opposite to the direction of rotation of the rotor plate and which extend to a height substantially equal to one-half of the refining gap. The outer portion of the inlet zone of the stator plate has a plurality of dams. Each of the dams has an upper ramp surface extending to an outer end having a curved profile. The outer portion of the inlet zone of the rotor plate and the inner portion of the inlet zone of the stator plate may each have either a smooth surface or a plurality of outwardly extending low profile protrusions.

Abstract: A refiner plate for the face of a refiner disc comprising a plurality of refiner segments arranged side-by-side on the face of the disc to form a substantially annular refining region. Each refiner segment has a plurality bars, chicanes and grooves for refining a lignocellulosic material and forming a zig-zag path for receiving and transmitting steam generated during the refining process. The chicanes define a series of substantially arcuate lines extending from a position intermediate the junction of the inlet and refining zones to the outer edge of the refiner plate in the counter-rotation direction.

Abstract: A refiner plate for the face of a refiner disc comprising a plurality of refiner segments arranged side-by-side on the face of the disc to form a substantially annular refining region. Each refiner segment has an inlet zone for receiving the material to be refined, an outer zone for refining and discharging refined material and an intermediate refining zone disposed intermediate the inlet zone and the outer zone. The outer zone has a pattern including a plurality of radially disposed bars defining an upper surface, a plurality of radially disposed grooves disposed intermediate the bars defining a lower surface, and dams traversing each of the grooves for restricting radial flow through the respective grooves. The dams include full height dams extending from the lower surface to the upper surface and partial height dams extending from the lower surface to a height intermediate the lower and upper surfaces. At least one full height dam is disposed in each of the grooves, as the radially outermost dam.

Abstract: A refiner plate for the face of a refiner disc comprising a plurality of refiner segments arranged side-by-side on the face of the disc to form a substantially annular refining region. Each refiner segment has an inner refining zone for receiving the material to be refined and an outer refining zone. The outer refining zone has a plurality of radially disposed bars defining an top surface and a plurality of radially disposed channels disposed intermediate the bars defining a lower base surface. At least one of the top surfaces has at least one radially extending groove defining a pair of blades and an intermediate base surface at the bottom of the groove. The intermediate base surface is positioned at a height intermediate the top surface and the lower base surface. The width of the grooves are narrower than the width of the channels.

Abstract: A refiner plate for the face of a refiner disc comprising a plurality of refiner segments arranged side-by-side on the face of the disc to form a substantially annular refining region. Each refiner segment has a plurality bars and grooves for refining a lignocellulosic material and a plurality of steam pockets for receiving, storing and transmitting steam generated during the refining process. Each steam pocket is defined by a series of gaps in adjacent bars such that the steam pocket extends radially and laterally across the refiner segment and such that the surface of the steam pocket is at or below the height of the groove surface. At least one bar extends radially between each adjacent steam pocket in a segment, thereby forming a discontinuous path for the movement of steam.