RU2819621C2 - Device and method for processing wood fibres - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a refining element for a fibre refiner. Refining element comprises refining body with refining surface including first and second refining plates separated by first and second refining grooves. First and second refining plates extend from respective first and second radially inner positions to corresponding first and second radially outer positions. First and second refining plates have the corresponding first and second height extending upwards from the bottom of the corresponding adjacent first or second refining groove. Second height is the minimum height of the second refining plates and is located at a distance from the second radially internal position, wherein the second height is at least 0.35 mm less than the first height. First refining plates are made with possibility of wood fibres refining, and the second refining plates are made with possibility of fibre bundles refining.

EFFECT: invention makes it possible to carry out the process of refining and fibre separation within the limits of a single refiner.

17 cl, 25 dwg

Description

Cross reference to related applications

This application is a continuation in part of US Patent Application No. 15/860,055, filed January 02, 2018 (Patent Attorney Case No. TEC-119945-US), which is related to US Patent Application No. 15/860,006, filed January 02 2018 (Patent Attorney Case No. TEC-120257-US). In addition, this application claims dual priority to US Patent Application No. 15/860,006.

Field of the present invention

The present invention relates generally to the processing of wood fibers in a refiner and, more particularly, to an apparatus and method for refining wood fibers and refining fiber bundles.

BACKGROUND OF THE INVENTION

Disc-type refiners are traditionally used to process wood fibers during the paper product manufacturing process. Such refiners contain first and second refining elements, between which there is a refining space. Each of the first and second refining elements includes a plurality of refining plates separated by refining grooves, the refining plates defining cutting surfaces for cutting wood fibers. During operation, at least one of the first and second refining elements rotates relative to the other, and during rotation, the cutting surfaces of the refining plates cut wood fibers processed in the refiner. After processing the wood fibers in the refiner, the treated wood fibers can be further processed in subsequent paper product manufacturing processes to produce paper products. In some cases, the wood fibers may be further processed, such as in a separate cone mill type refiner or deflocculator. As is known in the art, conical refiners operate in the same manner, except that the refining elements are located on a conical surface instead of a disk.

Brief Disclosure of the Present Invention

In accordance with a first aspect of the present invention, there is provided a refining element for a pulp refiner. The refining element comprises a refining body having a refining surface containing first refining plates separated by first refining grooves and extending from a first radially inner position to a first radially outer position on the refining surface, and second refining plates separated by second refining grooves and extending from a second radially inner position to a second radially outer position on the refining surface, the second radially outer position being located closer to the outermost portion of the refining body than the first radially outer position. The first refining plates have a first height extending upward from the bottom of the adjacent first refining groove, and the second refining plates have a second height extending upward from the bottom of the adjacent second refining groove. The second height represents the minimum height of the second refining plates and is spaced from the second radially inward position, the height being at least about 0.35 mm less than the first height. The first refining plates are configured to refine wood fibers, and the second refining plates are configured to refine fiber bundles.

The minimum height of the second refining plates may be near the second radially outer position.

The first height may be substantially constant in the longitudinal direction throughout the first refining plates.

The first height may be from about 4.0 mm to about 10.0 mm. The second height may be less than the first height, the difference being from about 0.35 mm to about 7.0 mm, or less than the first height, the difference being from about 0.7 mm to about 7.0 mm.

The second refining plates may be integral with the first refining plates such that the second refining plates extend from a first radially outer position to a second radially outer position.

Each of the second refining plates may be inclined downward substantially continuously over at least a portion of each of the second refining plates extending between the first radially outer position and the second radially outer position.

At least some of the first refining grooves may be provided with baffles.

The first height of the first refining plates may be a first maximum height, and the second refining plates may have a second maximum height extending upward from the bottom of an adjacent second refining groove, wherein the radially outer portion of each of the first refining plates may have a stepwise decrease from the first maximum height to the second maximum height, and wherein the second maximum height may be at least about 1.5 mm less than the first maximum height.

The refining element may further comprise third refining plates separated by third refining grooves and fourth refining plates separated by fourth refining grooves. Each of the third refining plates may extend to a third radially outer position on the refining surface, and each of the fourth refining plates may extend to a fourth radially outer position on the refining surface that is closer to the outermost portion of the refining body than the third radially outer position . The third refining plates may have a third height extending upward from the bottom of the adjacent third refining groove, and the fourth refining plates may have a fourth height extending upward from the bottom of the adjacent fourth refining groove. The fourth height may be the minimum height of the fourth refining plates and may be near the fourth radially outer position. The fourth height may be at least about 0.35 mm less than the third height. The third refining plates may be configured to refine wood fibers, and the fourth refining plates may be configured to refine fiber bundles.

The third refining plates may be integral with the second refining plates such that the third refining plates extend from a second radially outer position to a third radially outer position, and the fourth refining plates may be integral with the third refining plates such that the fourth refining plates the plates extend from a third radially outer position to a fourth radially outer position.

The third height of the third refining plates may be a third maximum height, and the fourth refining plates may be a fourth maximum height extending upward from the bottom of an adjacent fourth refining groove, wherein the radially outer portion of each of the third refining plates may comprise a step decrease from the third maximum height to a fourth maximum height, and wherein the fourth maximum height may be at least about 1.5 mm less than the third maximum height.

In accordance with a second aspect of the present invention, a pulp refiner is provided. The pulp refiner contains: a frame, at least a first pair of refining elements and a rotor. The refining elements comprise a first refining element connected to the frame and containing a first refining body, and a second refining element connected to the frame and containing a second refining body. The first refining body includes a first refining surface comprising: first refining plates separated by first refining grooves and extending from a first radially inward position on the refining surface to a first radially outer position on the refining surface, and second refining plates separated by second refining grooves and extending from the second a radially inward position on the refining surface to a second radially outer position on the refining surface, the second radially outer position being closer to the outermost portion of the refining body than the first radially outer position. The first refining plates have a first height extending upward from the bottom of the adjacent first refining groove, and the second refining plates have a second height extending upward from the bottom of the adjacent second refining groove. The second height represents the minimum height of the second refining plates and is spaced from the second radially inward position. The second height is at least about 0.35 mm less than the first height. The second refining element has a second refining surface containing refining plates of the second refining element separated by refining grooves of the second refining element. The first refining element is spaced from the second refining element, defining a refining space between them, and at least some of the refining plates of the second refining element are located so that they are opposite the second refining plates, defining a gap between some of the refining plates of the second refining element and second refining plates. The rotor is connected to one of the first refining element and the second refining element such that when the rotor rotates, one element of the first and second refining elements moves relative to the other element. When the wood fiber slurry containing wood fibers enters the frame, the wood fiber slurry passes through the refining space so that a significant number of wood fibers in the wood fiber slurry are refined, and a plurality of wood fiber bundles in the wood fiber slurry are separated.

The minimum height of the second refining plates may be near the second radially outer position.

The first height may be substantially constant in the longitudinal direction throughout the first refining plates.

The second height may be at least about 0.7 mm less than the first height. The first height of the first refining plates may be a first maximum height, and the second refining plates may have a second maximum height extending upward from the bottom of an adjacent second refining groove, wherein a radially outer portion of each of the first refining plates may comprise a step decrease from the first maximum height to the second maximum height, and wherein the second maximum height may be at least about 1.5 mm less than the first maximum height.

The refining plates of the second refining element may comprise: first refining plate elements extending from a first radially inward position to a first radially outer position on the second refining surface, and second refining plate elements extending to a second radially outer position on the second refining surface that is closer to the most distal part of the second refining body than the first radially outer position. The first refining plate elements may have a first refining plate height extending upward from the bottom of the adjacent groove, and the second refining plate elements may have a second refining plate height extending upward from the bottom of the adjacent groove. The height of the second refining plates may be a minimum height of the elements of the second refining plates and may be proximate the second radially outer position. The height of the second refining plates may be at least about 0.35 mm less than the height of the first refining plates.

In accordance with a third aspect of the present invention, a method for treating wood fibers is provided. The method includes providing a refiner containing at least a first pair of refining elements. The refining elements contain: a first refining element containing a first refining body, and a second refining element containing a second refining body. The first refining body has a first refining surface comprising: first refining plates separated by first refining grooves and having a first height extending upward from the bottom of the adjacent first refining groove, and second refining plates separated by second refining grooves and having a second height extending upward from the bottom adjacent second refining groove. The second refining body has a second refining surface containing refining plates of a second refining element separated by refining grooves of the second refining element. The first refining element is spaced from the second refining element, defining a refining space between them, and at least some of the refining plates of the second refining element are located so that they are opposite the second refining plates, defining a gap between some of the refining plates of the second refining element and second refining plates. The method further includes: rotating at least one of the first refining element and the second refining element such that the first and second refining elements move relative to each other; introducing a slurry of wood pulp containing wood fibers into the refiner such that the slurry passes through the refining space; and applying axial pressure to at least one of the first refining element and the second refining element while introducing the slurry. The gap between some of the refining plates of the second refining element and the second refining plates increases over at least a section of the second refining plates in a direction extending from a first radially inward position to a first radially outer position on the first refining surface. At least some of the wood fiber bundles passing through the gap are separated.

The second height may be the minimum height of the second refining plates and may be near the first radially outer position. The second height may be at least about 0.35 mm less than the first height.

Brief Description of the Figures

While the specification is consistent with the claims, having disclosed and specifically claimed the present invention, the inventors believe that the present invention will be better understood from the following description in conjunction with the accompanying drawings in which like numerals designate like elements, and wherein:

in fig. 1 is a schematic partial sectional view of a disk refiner;

in fig. 2 and 3 are top views of the first and second refining body, respectively;

in fig. 4A and 4B are top views of a refining surface section of the first refining body illustrated in FIG. 2;

in fig. 5A and 5B are top views of a refining surface section of the second refining body illustrated in FIG. 3;

in fig. 6A is a partial sectional view of the refining body taken along line 6A-6A in FIG. 4A and 5A;

in fig. 6B is a partial sectional view of the refining body taken along line 6B-6B in FIG. 4B and 5B;

in fig. 7 is a partial sectional view taken along line 7-7 in FIG. 4A, 4B, 5A, and 5B;

in fig. 8 and 9 are partial sectional views of a refining plate on a first refining body that is spaced and located above a corresponding refining plate on a second refining body;

in fig. 10 and 11 are top views of portions of the first and second refining bodies, respectively, containing a plurality of radially extending sector segments;

in fig. 12A and 12B are partial cross-sectional views of the sector segment refining plates illustrated in FIG. 10 and 11, with one refining body being spaced and located above the other refining body;

in fig. 13 and 14 are top views of the first and second refining bodies, respectively, containing teeth;

in fig. 15 is a top view of a refining surface section of the first refining body illustrated in FIG. 13;

in fig. 16 is a top view of a refining surface section of the second refining body illustrated in FIG. 14;

in fig. 17 is a partial sectional view of a refining plate and a tooth on a first refining body that is spaced and located above a second refining body containing a refining plate and teeth;

in fig. 18 is a flow chart illustrating an exemplary method for processing wood fibers;

in fig. 19A is a partial sectional view of the refining body similar to that in FIG. 6A;

in fig. 19B is a partial sectional view of the refining body similar to that of FIG. 6B; And

in fig. 20 is a flow diagram illustrating another exemplary process for processing wood fibers.

Detailed Disclosure of the Present Invention

The following detailed description of preferred embodiments contains reference to the accompanying figures, which form a part thereof, and in which specific preferred embodiments in which the present invention may be practiced are presented by way of illustration and not by way of limitation. It should be understood that other embodiments may be used and that changes may be made without departing from the spirit or scope of the present invention.

In fig. 1 illustrates a schematic partial sectional view of a disk refiner according to the present invention. Disc refiner 10 includes a housing with a first housing section 12 and a second housing section 14, which may be bolted or otherwise connected in a fixed manner to each other. Body sections 12, 14 define an inlet 16, an outlet 18, and an internal cavity 64 of a refiner that contains one or more pairs of refining elements. The embodiment illustrated in FIG. 1 is a double-disc refiner 10 including two pairs of refining elements, for example, a first refining element 20 paired with a second refining element 30, and a third refining element 40 paired with a fourth refining element 50. The first refining element 20 includes a first refining body 22 with a first refining surface 24, and a second refining element 30 includes a second refining body 32 with a second refining surface 34. A third refining element 40 contains a third refining body 42 and a third refining surface 44, and a fourth refining element 50 contains a fourth refining body 52 and a fourth refining surface surface 54. Each of the refining elements 20, 30, 40, 50 is connected to a main support frame comprising a fixed support frame 66 attached to the first body section 12 and a movable support frame 68, as described herein

The first, second, third and fourth refining bodies 22, 32, 42, 52 may typically be disc-shaped with substantially the same outer diameter (see FIGS. 2 and 3). The first and second refining elements 20, 30 are arranged such that the first refining surface 24 faces the second refining surface 34, and the third and fourth refining elements 40, 50 are located such that the third refining surface 44 faces the fourth refining surface 54. First the refining element 20 is spaced from the second refining element 30, which defines a first refining space 60 between the respective refining surfaces 24, 34. The third refining element 40 is spaced from the fourth refining element 50, which defines a second refining space 62 between the respective refining surfaces 44 54. Disc refiner 10 may have a design similar to that illustrated in US Patent Application Publication No. 2006/0037728 A1, the disclosure of which is incorporated herein by reference.

According to the embodiment which is shown in FIG. 1, the first and fourth refining elements 20, 50 are stationary, and the second and third refining elements 30, 40 rotate with respect to the first and fourth refining elements 20, 50. The first refining element 20 may be fixedly attached to the support frame 66 by bolts or other suitable fastenings (not illustrated). The second and third refining elements 30, 40 may be attached to a support 70 that is attached to and extends radially outward from the rotating shaft 72. The support 70 is attached to the shaft 72 such that it rotates with the shaft 72 and is also capable of axial movement along the shaft 72. The shaft 72 is driven by the first motor 74 such that the support 70 and the second and third refining elements 30, 40 rotate with the shaft 72 during operation of the disk refiner 10. The shaft 72 has a central axis 72A, which is typically coaxial with the axis of rotation. second and third refining elements 30, 40. The shaft 72 may be rotatably mounted on a fixed support frame 66 such that the first and second refining elements 30, 40 are connected to the main support frame. The support 70 may be movable in an axial direction along the shaft 72, for example, substantially along the central axis 72A, with respect to the first and fourth refining elements 20, 50, as described herein. The fourth refining element 50 may be fixedly attached to the movable support frame 68 by bolts or other suitable fasteners (not illustrated). Therefore, the support 70 and shaft 72 may define a rotor coupled to the main support frame such that the second and third refining elements may define rotating rotor elements, and the first and fourth refining elements 20, 50 may define non-rotating stator elements. The rotation of the rotor carries out the movement of the second and third refining elements 30, 40 in relation to the first and fourth refining elements 20, 50, respectively.

The movable support frame 68 may be mounted in the second housing section 14 and is coupled to a second motor 76, which may be a reversible electric motor having a fixed position. The second motor 76 moves the movable support frame 68 in a substantially horizontal (i.e., axial) direction, represented by arrow A. The refiner 10 may include, for example, a screw jack (not illustrated) attached to the second motor 76 and a movable support frame 68. wherein the second motor 76 may rotate the screw jack to move the movable support frame 68 to which, for example, the fourth refining element 50 is attached. This movement adjusts the size of the gaps, i.e. first and second refining spaces 60, 62 defined between the first and second refining elements 20, 30 and the third and fourth refining elements 40, 50 (see also FIGS. 8 and 9). In other embodiments (not illustrated), adjustment of the size of the gaps may be achieved by means of one or more magnetic bearings. Magnetic bearings that adjust the axial position of the shaft 72 may be used to adjust the position of rotating rotor members that are fixedly attached to the shaft 72. Magnetic bearings may be used to adjust the axial position of one or more additional movable sections of the main support frame, i.e. a movable support frame 68 to which one or more non-rotating stator elements are attached.

As will be discussed later herein, a slurry of wood pulp containing wood fibers passes through the refining spaces 60, 62. As the screw jack rotates in the first direction, it causes the movable support frame 68 and the fourth refining element 50 to move inward toward the third refining element 40. The fourth refining element 50 then applies an axial force to the pulp suspension passing through the second refining space 62, which in turn applies an axial force to the third refining element 40, forcing the third refining element 40, the support 70 and the second refining element element 30 to move inward toward the first refining element 20. When the jack screw rotates in a second direction opposite to the first direction, it causes the movable support frame 68 and the fourth refining element 50 to move outward from the third refining element 40. This reduces the axial force applied by the fourth refining element 50 to the pulp suspension passing through the second refining space 62, which in turn reduces the axial force applied by the pulp suspension to the third refining element 40. In this case, the axial force applied by the fiber suspension passing through the first refining space 60 is sufficient to cause the second refining element 30, the support 70 and the third refining element 40 to move towards the fourth refining element 50. This occurs as long as the axial forces exerted by the pulp suspension passing through remain approximately equal through the first and second refining spaces 60, 62, to the second and third refining elements 30 and 40.

In some embodiments (not illustrated), disk refiner 10 may further comprise an additional motor and a second rotating shaft, and first and/or fourth refining elements 20, 50 may be coupled to the second rotating shaft such that the first and/or fourth refining elements 20, 50 may rotate in the opposite direction with respect to the second and/or third refining elements 30, 40, respectively. In other embodiments (not illustrated), disk refiner 10 may comprise only one pair of refining elements, wherein one refining element is a non-rotating stator element and the other refining element is a rotating rotor element. In the following embodiments (not illustrated), the disk refiner may comprise three or more pairs of refining elements. In the following embodiments (not illustrated), disk refiner 10 may be a conical refiner with one or more pairs of refining elements

In fig. 2 and 3 are top views of the refining surfaces 24, 34 of the first refining body 22 and the second refining body 32, respectively, for use in a pulp refiner according to one embodiment of the present invention. Although not discussed in detail herein, the design of the refining surfaces 44, 54, respectively, of the third and fourth refining bodies 42, 52 (see FIG. 1) may be substantially similar to the design of the refining surfaces 24, 34, respectively, of the first and second refining bodies. tel 22, 32.

As shown in FIG. 1 and 2, the first refining body 22 may comprise a plurality of sections, such as sections 22A-22C, which are connected to each other by bolts or otherwise to form a disk-shaped refining body 22 comprising a radially outer edge 27. The refining surface 24 contains a plurality of elongated refining bars. plates 26 separated from each other by refining grooves 28. Although not shown in FIG. 2, it will be understood that other sections (not designated by numbers) of the first refining body 22 will likewise comprise refining plates 26 and refining grooves 28. The refining plates 26 extend radially outward from a radially inboard position 23 toward a radially outer edge 27 of the first refining body. 22. The refining plates 26 can be inclined at various angles, as shown in FIG. 2, and each section 22A-22C may include one or more segments (not designated by separate numbers) of refining plates 26 that are inclined in different directions. Refining plates 26 and refining grooves 28 within each section 22A-22C in FIG. 2 may be otherwise similar in design.

As shown in FIG. 3, the second refining body 32 may similarly comprise a plurality of sections, such as sections 32A-32C, which are connected to each other by bolts or otherwise to form a disc-shaped refining body 32 including a radially outer edge 37. The refining surface 34 includes a plurality of elongated refining plates 36 separated from each other by refining grooves 38. Although not shown in FIG. 3, it will be understood that other sections (not designated by numbers) of the second refining body 32 will likewise comprise refining plates 36 and refining grooves 38. The refining plates 36 extend radially outward from a radially inboard position 33 toward a radially outer edge 37 of the second refining body. body 32. The refining plates 36 can be inclined at different angles, as shown in FIG. 3, and each section 32A-32C may include two or more segments (not designated by separate numbers) of refining plates 36 that are inclined in different directions. Refining plates 36 and refining grooves 38 within each section 32A-32C in FIG. 3 may be otherwise similar in design.

The paths of movement of the wood pulp slurry containing wood fibers through the refiner 10 are illustrated by arrows B in FIG. 1. As shown in FIG. 1-3, the pulp slurry enters disk refiner 10 through inlet 16 and enters refiner interior cavity 64 through central opening 21 in first refining element 20. Refiner interior cavity 64 may be defined in part by a fixed support frame 66 and a movable support frame 68. The refining surfaces 24, 34 may contain one or more additional rows of refining plates (not designated by numbers), such as plates located near the center of the refining bodies 22, 32, for example, near the central hole 21. These additional refining plates may be wider and located at at larger intervals than the other refining plates 26 to crush large bundles of fibers before they enter the refining space 60. The wood fibers move radially outward between the refining elements 20, 30, 40, 50. The first refining space 60 is defined between the first and second refining elements 20, 30, and a second refining space 62 defined between the third and fourth refining elements 40, 50 define separate trajectories along which wood fibers can move from inlet 16 to outlet 18. The authors believe that wood fibers only pass at a time through one of the first and second refining spaces 60, 62. The refining grooves 28, 38 can be considered as part of the refining space 60 defined between the first and second refining elements 20, 30. The authors believe that the bulk of the flow of wood fibers through the refining space 60 extends through the refining grooves 28, 38. Likewise, the refining grooves (not illustrated) of the third and fourth refining elements 40, 50 can be considered as part of the refining space 62 defined between the third and fourth refining elements 40, 50. The authors believe that the main the mass flow of wood fibers through the refining space 62 passes through the refining grooves (not designated by numbers) of the third and fourth refining elements 40, 50. After processing, the wood fibers exit the refiner 10 through outlet 18 at least in part by centrifugal force.

In fig. 4A and 4B are detailed views of one portion of the refining surface 24 of the first refining body 22, and FIG. 5A and 5B are detailed views of a corresponding portion of the refining surface 34 of the second refining body 32. FIG. 6A and 6B are partial cross-sectional views of the refining bodies 22, 32 taken along lines 6A-6A and 6B-6B, respectively, illustrating two embodiments of the refining plate 26, 36 as shown in FIG. 4A, 4B, 5A and 5B. In fig. 7 is a partial sectional view taken along line 7-7 in FIG. 4A, 4B, 5A and 5B.

According to the embodiments shown in FIGS. 4A, 5A, 6A and 7, each refining plate 26, 36 may include a first refining plate 26A, 36A and a second refining plate 26B, 36B. The first refining plates 26A, 36A may be separated from each other by the first refining grooves 28A, 38A, and the second refining plates 26B, 36B may be separated from each other by the second refining grooves 28B, 38B. The first and second refining grooves 28A, 38A, 28B, 38B may have a width W _G ranging from about 2 mm to about 6 mm. As shown in FIG. 6A and 7, the first refining plates 26A, 36A have a first maximum height H ₁ extending upward from the bottom F ₁ of the adjacent first refining groove 28A, 38A, and the second refining plates 26B, 36B have a second maximum height H ₂ extending upward from the bottom F ₂ of the adjacent second refining groove 28B, 38B, the second maximum height H ₂ being less than the first maximum height H ₁ . The minimum height difference between H ₁ and H ₂ is indicated as D ₁ in Fig. 6A. In some examples, the radially outer portion RO ₁ of the first refining plate 26A, 36A may comprise a stepwise reduction from a first maximum height H ₁ to a second maximum height H ₂ .

In some examples, the second maximum height H ₂ may be at least 0.35 mm (±0.05 mm) less than the first maximum height H ₁ . In other examples, the second maximum height H ₂ may be at least 0.70 mm (±0.05 mm) less than the first maximum height H ₁ . In the following examples, the first maximum height Hi of the first refining plates 26A, 36A, which is measured from the bottom F ₁ of the adjacent first refining groove 28A, 38A, may be from about 4 mm to about 10 mm (±0.5 mm). This range includes all intermediate values and subranges, including, for example, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8, 0, 8.5, 9.0, 9.5 and 10.0 mm. In a specific example, the second maximum height H ₂ of the second refining plates 26B, 36B, which is measured from the bottom F ₂ of the adjacent second refining groove 28B, 38B, may be less than the first maximum height Hi, and their difference may be from about 0.35 mm to approximately 1.5 mm (±0.5 mm). This range includes all intermediate values and subranges, including, for example, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0, 75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45 and 1.5 mm. In another specific example, the second maximum height H ₂ of the second refining plates 26B, 36B, which is measured from the bottom F ₂ of the adjacent second refining groove 28B, 38B, may be less than the first maximum height H ₁ , and their difference may be from about 0. 7 mm to approximately 1.5 mm (±0.05 mm). This range includes all intermediate values and subranges, including, for example, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.05, 1, 1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45 and 1.5 mm. In the following examples, in which the radially outer portion RO ₁ of the first refining plates 26A, 36A comprises a step reduction from a first maximum height H ₁ to a second maximum height H ₂ , the second maximum height H ₂ may be at least about 1.5 mm ( ±0.05 mm) less than the first maximum height H ₁ . In some cases, the second maximum height H ₂ may be at least about 2.0 mm (±0.05 mm) less than the first maximum height H ₁ , and in other cases the second maximum height H ₂ may be at least about 2.0 mm (±0.05 mm) less than the first maximum height H 1 3.0 mm (±0.05 mm) less than the first maximum height H ₁ .

Each of the first refining plates 26A, 36A extends from a radially inward position P ₁ on the refining surface 24, 34 to a first radially outer position P ₂ on the refining surface 24, 34. Each of the second refining plates 26B, 36B extends to a second radially outer position P ₃ on the refining surface 24, 34. The second radially outer position P ₃ may be closer to the outermost portion, for example, of the radially outer edge 27, 37, of the refining body 22, 32 than the first radially outer position P ₂ . In some examples, the radially inward position P ₁ may include a position at or near the radially inward position 23, 33. The second refining plates 26B, 36B may have a longitudinal length L ₁ ranging from about 0.6 cm to about 10 cm and preferably from about 2 cm to about 10 cm, and preferably from about 2 cm to about 10 cm. The first refining plates 26A, 36A and the second refining plates 26B, 36B may have a width W26 extending between the side edges of the respective refining plates 26A, 36A, 26B, 36B and a component from about 2.0 mm to about 8.0 mm. This range includes all intermediate values and subranges, including, for example, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6, 0, 6.5, 7.0, 7.5 and 8.0 mm.

In some embodiments, the second refining plates 26B, 36B may be integral with the first refining plates 26A, 36A, as illustrated in FIG. 4A, 5A and 6A such that the second refining plates 26B, 36B extend from the first radially outer position P ₂ to the second radially outer position P ₃ . According to a specific embodiment, the second refining plates 26B, 36B may have a continuous downward slope from a first radially outer position P ₂ to a second radially outer position P ₃ . As shown in FIG. 6A, the height of the second refining plates 26B, 36B may be continuously decreased over substantially the entire length in the longitudinal direction L ₁ from a second maximum height H ₂ to a second minimum height H _2' . According to another specific embodiment, the second refining plates 26B, 36B may extend substantially horizontally from a first radially outer position P ₂ to a second radially outer position P ₃ , as indicated by the dashed line in FIG. 6A such that the second refining plates 26B, 36B are at the level of the second maximum height H ₂ throughout substantially the entire length in the longitudinal direction L ₁ of the second refining plates 26B, 36B. In other embodiments (not illustrated), the first refining plates 26A, 36A may be radially spaced from the second refining plates 26B, 36B.

As shown in FIG. 4A, 5A and 7, the refining surfaces 24, 34 may include baffles 29, 39 present in at least some of the first refining grooves 28A, 38A. The baffles 29, 39 may have a height that is substantially the same or less than the height of the adjacent first refining plates 26A, 36A. The baffles 29, 39 serve to divert the wood fibers from the first refining grooves 28A, 38A so that the wood fibers enter the first and second refining plates 26A, 36A, 26B, 36B.

As shown in FIG. 1, 4A, 5A and 6A, when the wood pulp slurry containing wood fibers enters the frame 66, such as the inlet 16, of the refiner 10, the first refining plates 26A, 36A are configured to refine the wood fibers in the pulp slurry, while while the second refining plates 26B, 36B are configured to crush or separate the fiber bundles. Refining can be used to separate and crush small fiber clumps, promote external or internal fibrillation to effect fiber bonding, and/or cut a significant number of long wood fibers in a wood pulp suspension such that the lengths of long wood fibers are reduced. However, the refining process also causes some of the wood fibers to re-form small, dense fiber bundles ("flakes"), particularly when long fibers such as softwood fibers are degummed. Fiber bundles can adversely affect the tensile strength, formability, and other properties of the final paper product, initiate the formation of pulp filaments that plug downstream components, and/or prevent fluid/water from flowing out of the fibers during manufacture of the paper products. Thus, the flakes must be broken down after refining in a process termed "de-fibering". As used herein, the term "de-fibering" is used to refer to the process of breaking down the bundles of fibers that are formed during refining. When refining is carried out by a traditional wood pulp refiner, de-fibmentation typically occurs in one or more downstream refiners, which are often operated at low power and are either cone mill type refiners or deflocculators. The use of separate refiners or deflocculators increases the cost and complexity of the system. In addition, cone mill type refiners and their associated piping and tanks and downstream machine pool can accumulate residual amounts of fibers from previous batches and allow continuous formation of fiber bundles. Processing in cone mill type refiners can degrade the properties of the fibers when co-refining different grades of wood pulp suspensions. We believe that the refining elements 20, 30, 40, 50 according to the present invention solve these problems by installing refining plates 26A, 26B, 36A, 36B having different heights so that refining and defibration can be carried out within a single refiner 10 .

The first maximum height H ₁ of the first refining plates 26A, 36A is greater than the second maximum height H ₂ and this means that the wood fibers are subjected to highly intense shear and compression forces as the fibers pass through a portion of the refining space 60 that is at least partially defined by the first refining grooves 28A, 38A, and enter the cutting side edges 126A, 136A of the first refining plates 26A, 36A on opposite first and second refining surfaces 24, 34 (see also FIGS. 8 and 9). Therefore, the portion of the refining space 60 that is at least partially defined by the first refining grooves 28A, 38A and extends from a radially inward position P ₁ on the refining surface 24, 34 to a first radially outer position P ₂ on the refining surface 24, 34 may at least at least partially define the refining zone. In some examples, the radially inward position 23, 33 of the corresponding refining body 22, 32 may define the beginning of the refining zone. As the refining fibers pass into a portion of the refining space 60 that is at least partially defined by the second refining grooves 28B, 38B (e.g., from approximately the first radially outer position P ₂ to approximately the second radially outer position P ₃ in FIG. 6A), the second refining plates 26B, 36B have a second maximum height H ₂ and the intensity of the force that is applied to the fibers decreases in response to the decrease in height (see also FIGS. 8 and 9). Thus, a portion of the refining space 60 that is at least partially defined by the second refining grooves 28B, 38B and extends from a first radially outer position P ₂ to a second radially outer position P ₃ on the refining surface 24, 34 may at least partially define a zone fiber disintegration. The authors believe that reducing the force applied to the fibers in the defibration zone results in smaller fiber bundles that are formed during refining, with no or only minimal refining of the fibers. According to the embodiment shown in FIG. 6A, the second refining plates 26B, 36B form an annular space defining a de-fiber zone around the radially outer portion (not designated by a separate number) of the first and second refining bodies 22, 32. The authors believe that the second maximum height H ₂ of the second refining plates 26B, 36B should be at least about 0.35 mm (±0.05 mm) less than the first maximum height Hi of the first refining plates 26A, 36A to stop refining the fibers and begin defibration. The refining zone may be 60% or more of the total area determined by the sum of the refining and defibration zones on each refining surface 24, 34.

According to the embodiments shown in FIGS. 4B, 5B, and 6B, each refining plate 26', 36' may include a first refining plate 26A', 36A', a second refining plate 26B', 36B', a third refining plate 26C, 36C, and a fourth refining plate 26D, 36D. The first refining plates 26A', 36A' and the second refining plates 26B', 36' may be substantially similar to the first refining plates 26A, 36A and the second refining plates 26B, 36B, as illustrated in FIG. 4A, 5A, 6A, and 7 and as described herein, but the first and second refining plates 26A', 36A', 26B', 36B' may extend radially outward over a shorter distance. The first refining plates 26A', 36A' may be separated from each other by the first refining grooves 28A', 38A', and the second refining plates 26B', 36B' may be separated from each other by the second refining grooves 28B', 38B'. The first and second refining grooves 28A', 38A', 28B', 38B' may have a width W _G of from about 2 mm to about 6 mm. This range includes all intermediate values and subranges, including, for example, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5 and 6. 0 mm. The third refining plates 26C, 36C may be separated from each other by the third refining grooves 28C, 38C, and the fourth refining plates 26D, 36D may be separated from each other by the fourth refining grooves 28D, 38D. As shown in FIG. 6B, the third refining plates 26C, 36C include a third maximum height H ₃ extending upward from the bottom F ₃ of the adjacent third refining groove 28C, 38C, and the fourth refining plates 26D, 36D include a fourth maximum height H ₄ extending upward from the bottom F ₄ of the adjacent a fourth refining groove 28D, 38D, wherein the fourth maximum height H ₄ is less than the third maximum height H ₃ . The third maximum height H ₃ may be substantially equal to the first maximum height H ₁ , and the fourth maximum height H4 may be substantially equal to the second maximum height H ₄ . The minimum height difference between H ₃ and H ₄ is shown as D ₂ in FIG. 6B. In some examples, the radially outer portion RO ₂ of the third refining plate 26C, 36C may include a step reduction from a third maximum height H ₃ to a fourth maximum height H ₄ . The third and fourth refining grooves 28C, 38C, 28D, 38D may have a width W _G ranging from about 2 mm to about 6 mm. This range includes all intermediate values and subranges, including, for example, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5 and 6. 0 mm.

In some examples, the fourth maximum height H ₄ may be at least 0.35 mm (±0.05 mm) less than the third maximum height H ₃ . In other examples, the fourth maximum height H ₄ may be at least 0.70 mm (±0.05 mm) less than the third maximum height H ₃ . In the following examples, the third maximum height H ₃ of the third refining plates 26C, 36C, which is measured from the bottom F ₃ of the adjacent third refining groove 28C, 38C, can be from about 4 mm to about 10 mm (±0.5 mm). This range includes all intermediate values and subranges, including, for example, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8, 0, 8.5, 9.0, 9.5 and 10.0 mm. In a specific example, the fourth maximum height H ₄ of the fourth refining plates 26D, 36D, which is measured from the bottom F ₄ of the adjacent fourth refining groove 28D, 38D, may be less than the third maximum height H ₃ , and their difference may be from about 0.35 mm to approximately 1.5 mm (±0.05 mm). This range includes all intermediate values and subranges, including, for example, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0, 75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45 and 1.5 mm. In another specific example, the fourth maximum height H ₄ of the fourth refining plates 26D, 36D, which is measured from the bottom F ₄ of the adjacent fourth refining groove 28D, 38D, may be less than the third maximum height H ₃ , and their difference may be from about 0. 7 mm to approximately 1.5 mm (±0.05 mm). This range includes all intermediate values and subranges, including, for example, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.05, 1, 1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45 and 1.5 mm. In the following examples, in which the radially outer portion RO ₂ of the third refining plates 26C, 36C comprises a step reduction from a third maximum height H ₃ to a fourth maximum height H ₄ , the fourth maximum height H ₄ may be at least about 1.5 mm ( ±0.05 mm) less than the third maximum height H ₃ . In some cases, the fourth maximum height _H4 may be at least about 2.0 mm (±0.05 mm) less than the third maximum height _H3 , and in other cases the fourth maximum height _H4 may be at least about 2.0 mm (±0.05 mm) less than the third maximum height H3. 3.0 mm (±0.05 mm) less than the third maximum height H ₃ .

Each of the first refining plates 26A', 36A' extends from a radially inward position P _1' on the refining surface 24, 34 to a first radially outer position P _2' on the refining surface 24, 34. Each of the second refining plates 26B', 36B' extends to the second radially outer position P ₃ ' on the refining surface 24, 34. Each of the third refining plates 26C, 36C extends to the third radially outer position P ₄ on the refining surface 24, 34. Each of the fourth refining plates 26D, 36D extends to the fourth radially outer position P ₅ on the refining surface 24, 34. The fourth radially outer position P ₅ may be closer to the outermost part, for example, of the radially outer edge 27, 37 of the refining body 22, 32 than the first, second and third radially outer positions P _2' , P _3' and P ₄ . The fourth refining plates 26D, 36D may have a longitudinal length L ₂ of from about 0.6 cm to about 10 cm, and preferably from about 2 cm to about 10 cm. The third refining plates 26C, 36C and the fourth refining plates 26D, 36D may have a width (not specifically designated) extending between the side edges of the respective refining plates 26C, 36C, 26D, 36D and ranging from about 2.0 mm to about 8.0 mm. This range includes all intermediate values and subranges, including, for example, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6, 0, 6.5, 7.0, 7.5 and 8.0 mm.

In some embodiments, the second refining plates 26B', 36B' may be integral with the first refining plates 26A', 36A', as illustrated in FIG. 4B, 5B and 6B such that the second refining plates 26B', 36B' extend from a first radially outer position P _2' to a second radially outer position P _3' . According to some embodiments as illustrated in FIG. 4B, 5B and 6B, the third refining plates 26C, 36C may be integral with the second refining plates 26B', 36B' such that the third refining plates 26C, 36C extend from the second radially outer position P _3' to the third radially outer position P ₄ , and the fourth refining plates 26D, 36D may be integral with the third refining plates 26C, 36C such that the fourth refining plates 26D, 36D extend from the third radially outer position P ₄ to the fourth radially outer position P ₅ . According to a specific embodiment, the second refining plates 26B', 36B' may have a continuous downward slope from a first radially outer position P _2' to a second radially outer position P ₃ . As shown in FIG. 6B, the second refining plates 26B', 36B' may have a length in the longitudinal direction L ₁ of from about 0.6 cm to about 10 cm, and preferably from about 2 cm to about 10 cm. Height of the second refining plates 26B', 36B' may continuously decrease over substantially the entire length in the longitudinal direction L ₁ from the second maximum height H ₂ to the second minimum height H ₂ '. According to another specific embodiment, the second refining plates 26B', 36B' may extend substantially horizontally from a first radially outer position P _2' to a second radially outer position P ₃ ', as indicated by the dashed line in FIG. 6B such that the second refining plates 26B', 36B' are at the level of the second maximum height H ₄ throughout substantially the entire length in the longitudinal direction L ₁ of the second refining plates 26B', 36B'. According to a specific embodiment, the fourth refining plates 26D, 36D may have a continuous downward slope from a third radially outer position P ₄ to a fourth radially outer position P ₅ . As shown in FIG. 6B, the height of the fourth refining plates 26D, 36D may be continuously decreased over substantially the entire length in the longitudinal direction L ₂ from a fourth maximum height H ₄ to a fourth minimum height H _4' . According to another specific embodiment, the fourth refining plates 26D, 36D may extend substantially horizontally from the third radially outer position _P4 to the fourth radially outer position _P5 , as indicated by the dashed line in FIG. 6B such that the fourth refining plates 26D, 36D are at the level of the fourth maximum height H ₄ throughout substantially the entire length in the longitudinal direction L ₂ of the fourth refining plates 26D, 36D. In other embodiments (not illustrated), the third refining plates 26C, 36C may be radially spaced from the fourth refining plates 26D, 36D.

As shown in FIG. 4B, 5B and 7, the refining surface 24, 34 may include baffles 29, 39 present in at least some of the first and/or third refining grooves 28A', 38A', 28C, 38C as described herein.

The first refining plates 26A', 36A' in FIG. 4B, 5B and 6B are configured to refining wood fibers, and the second refining plates 26B', 36B' in FIG. 4B, 5B and 6B are configured to refine fiber bundles as described with respect to the first and second refining plates 26A, 36A, 26B, 36B in FIG. 4A, 5A and 6A. The third refining plates 26C, 36C are configured to refining wood fibers (similar to the first refining plates 26A', 36A'), while the fourth refining plates 26D, 36D are configured to refine fiber bundles (similar to the second refining plates 26B', 36B' ) as described in this document.

As shown in FIG. 1, 4B, 5B and 6B, portions of the refining space 60 that are at least partially defined by the first refining grooves 28A', 38A' and the third refining grooves 28C, 38C and extend from a radially inboard position P _1' to a first radially outer position P _{2 '} and from the second radially outer position P _{3 '} to the third radially outer position P ₄ on the refining surface 24, 34, may at least partially define the first and second refining zones, respectively, as described herein. Portions of the refining space 60 that are at least partially defined by the second refining grooves 28B', 38B' and the fourth refining grooves 28D, 38D and extend from the first radially outer position P _2' to the second radially outer position P _3' and from the third radially outer position P ₄ to the fourth radially outer position P ₅ on the refining surface 24, 34 may at least partially define the first and second defiber zones, respectively, as described herein. We believe that the second maximum height H ₄ of the second refining plates 26B', 36B' should be at least about 0.35 mm (±0.05 mm) less than the first maximum height H ₁ of the first refining plates 26A', 36A' to stop refining the fibers and start defibering. Likewise, the inventors believe that the fourth maximum height H ₄ of the fourth refining plates 26D, 36D should be at least about 0.35 mm (±0.05 mm) less than the third maximum height H ₃ of the third refining plates 26C, 36C, to stop refining the fibers and start defibering. The first and second refining zones may comprise 60% or more of the total area defined by the sum of the first and second refining and defibration zones on each refining surface 24, 34.

In fig. 8 and 9 are partial cross-sectional views of the first and second refining bodies 22, 32/132 of the first and second refining elements 20, 30/130 according to the present invention. The first refining element 20 is spaced and located adjacent and opposite the second refining element 30 (see FIG. 1). According to the embodiment which is shown in FIG. 8, the refining body according to the present invention, for example, the first refining body 22, is paired with a conventional refining body 132. The first refining body 22 includes a first refining plate 26A, a first refining groove 28A, a second refining plate 26B and a second refining groove 28B, which can correspond to the first and second refining plates 26A, 26B and the first and second refining grooves 28A, 28B, as described herein with respect to FIGS. 4A, 4B, 6A, 6B and 7. It should be understood that the features described in FIGS. 8 with respect to the first and second refining plates 26A, 26B and the first and second refining grooves 28A, 28B, apply equally to the third and fourth refining plates 26C, 26D and the third and fourth refining grooves 28C, 28D, respectively, as described herein document (see Figs. 4B, 5B and 6B). The conventional refining body 132 includes a conventional refining plate 136 that has the same height over substantially the entire length in the longitudinal direction of the refining plate 136 and the refining groove 138. In other embodiments (not illustrated), a non-rotating stator element, such as the first refining element 20, may include conventional refining plates that have the same height throughout substantially their entire length, and a rotating rotor element, for example, the second refining element 30 may include refining plates 26A, 26B and refining grooves 28A, 28B in accordance with the present invention (see FIG. 1)

The first gap G ₁ is defined in FIG. 8 between the outer surface S _26A of the first refining plate 26A and the outer surface S ₁₃₆ of the conventional refining plate 136. In examples in which the second refining plate 26B has a continuous downward slope, a second gap G ₂ may be defined between the outer surface S _26B of the second refining plate 26B and the outer surface of the conventional refining plate 136, wherein G ₂ is greater than G ₁ . In examples in which the second refining plate 26B extends substantially horizontally (represented in dashed lines in FIG. 8), a third gap G ₃ may be defined between the outer surface S _{26B' of} the second refining plate 26B and the outer surface S ₁₃₆ of the conventional refining plate 136, wherein G ₃ is more than G ₁ . As shown in FIG. 8, according to embodiments in which one of the second refining plates, for example, the second refining plate 26B, is inclined, the distance between the outer surface S _26B of the second refining plate 26B and the outer surface S ₁₃₆ of the conventional refining plate 136 can continuously increase over a period of at least a portion of the length in the longitudinal direction (not indicated; see FIGS. 6A and 6B) of the second refining plate 26B from the minimum distance corresponding to the third gap G ₃ to the maximum distance corresponding to the second gap G ₂ .

According to the embodiment which is shown in FIG. 9, one refining body according to the present invention, for example, a first refining body 22, is paired with another refining body according to the present invention, for example, a second refining body 32. The first refining body 22 includes a first refining plate 26A, a first refining groove 28A, a second a refining plate 26B and a second refining groove 28B, which may correspond to the first and second refining plates 26A, 26B and the first and second refining grooves 28A, 28B, as described herein with respect to FIGS. 4A, 4B, 6A, 6B and 7. The second refining body 32 includes a first refining plate 36A, a first refining groove 38A, a second refining plate 36B and a second refining groove 38B, which may correspond to the first and second refining plates 36A, 36B and the first and second refining grooves 38A, 38B, as described herein with respect to FIGS. 5A, 5B, 6A, 6B and 7. It should be understood that the features described in FIGS. 9 with respect to the first and second refining plates 26A, 26B, 36A, 36B and the first and second refining grooves 28A, 28B, 38A, 38B apply equally to the third and fourth refining plates 26C, 26D and the third and fourth refining grooves 28C, 28D, respectively, as described herein (see FIGS. 4B, 5B and 6B).

The first gap G ₁ is defined between the outer surface S _26A of the first refining plate 26A of the first refining body 22 and the outer surface S _36A of the first refining plate 36A of the second refining body 32. In examples in which the second refining plate 26B of the first refining body 22 and the second refining plate 36B the second refining body 32 simultaneously have a continuous downward slope, the gap G ₄ can be defined between the outer surface S _{26B of} the second refining plate 26B and the outer surface S _36B of the second refining plate 36B of the second refining body 32, and G ₄ is more than G ₁ . In examples in which one of the second refining plates, for example, the second refining plate 26B of the first refining body 22, has a continuous downward slope, and the other of the second refining plates, for example, the second refining plate 36B of the second refining body 32, extends substantially horizontally ( shown in dashed lines in FIG. 9), a gap G ₅ may be defined between the outer surface S _26B of the second refining plate 26B and the outer surface S _{36B' of} the second refining plate 36B, wherein G ₅ is greater than G ₁ . In examples in which the second refining plate 26B of the first refining body 22 and the second refining plate 36B of the second refining body 32 simultaneously extend substantially horizontally (represented in FIG. 9 by dashed lines), a gap G ₆ can be defined between the outer surface S _26B' of the second refining body 32. plate 26B and the outer surface S _36B' of the second refining plate 36B, wherein G ₆ is greater than G ₁ . In some specific examples, _G4 is greater than _G5 , and _G5 is greater than _G6 .

As shown in FIG. 9, according to embodiments in which one or both of the second refining plates 26B, 36B are inclined, the distance between the outer surfaces S _26B , S _26B' , S _36B , S _36B' of the second refining plates 26B, 36B can be continuously increased over at least part of the length in the longitudinal direction (not indicated; see FIGS. 6A and 6B) of one or both of the respective second refining plates 26B, 36B. For example, when one refining body, such as the first refining body 22, includes an inclined second refining plate 26B, the distance between the outer surfaces S _26B , S _{36B' of} the second refining plates 26B, 36B can increase from a minimum distance corresponding to the gap G ₆ to a maximum distance corresponding to the third gap G ₅ . When both refining bodies 22, 32 include inclined second refining plates 26B, 36B, the distance between the outer surfaces S26B, S36B of the second refining plates 26B, 36B may increase from a minimum distance corresponding to the gap G ₆ to a maximum distance corresponding to the second gap G ₄ .

According to all embodiments illustrated in FIGS. 8 and 9, when the rotating refining element (for example, the first refining element 20; see FIG. 1) rotates relative to the stationary refining element (for example, the second refining element 30/130; see FIG. 1), the pulp suspension, containing wood fibers, enters the frame 66, for example, the inlet 16, of the refiner 10 (see Fig. 1) and enters the refining space 60, defined between the first and second refining bodies 22, 32/132. As shown in FIG. 8, when wood fibers enter a portion of the refining space 60 that is at least partially defined by the first refining grooves 28A of the first refining body 22 and the refining grooves 138 of the second refining body 132, the first and second refining bodies 22, 132 are at a distance that defines the first a gap G ₁ between the first refining plates 26A of the first refining body 22 and the conventional refining plates 136 of the second refining body 132 such that the refining plates 26A and 136 cooperate with each other to refine the wood fibers as described herein. We believe that the first gap G ₁ should be less than about 0.9 mm (±0.05 mm) and preferably from about 0.2 mm to about 0.9 mm (±0.05 mm) in order to achieve refining. This range includes all intermediate values and subranges, including, for example, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0, 6, 0.65, 0.7, 0.75, 0.8, 0.85 and 0.9 mm. In some examples, the first gap G ₁ may be from about 0.1 mm to about 0.5 mm (±0.05 5 mm). This range includes all intermediate values and subranges, including, for example, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45 and 0. 5 mm.

In addition, as shown in FIG. 8, as wood fibers extend into a portion of the refining space 60 that is at least partially defined by the second refining grooves 28B of the first refining body 22 and the refining grooves 138 of the second refining body 132, the distance between the second refining plates 26B of the first refining body 22 and the refining plates 136 of the second increases. refining body 132, such that the authors believe that refining stops and defibration begins. According to embodiments in which the second refining plates 26B have a continuous downward slope, the distance increases from the first gap G ₁ to the second gap G ₂ . In embodiments in which the second refining plates 26B extend substantially horizontally, the distance increases from the first gap G ₁ to the third gap G ₃ . The authors believe that the distance between the second refining plates 26B of the first refining body 22 and the refining plates 136 of the second refining body 132, i.e. G ₂ or G ₃ must be between about 0.9 mm and about 1.5 mm (±0.05 mm) for defibration to occur. This range includes all intermediate values and subranges, including, for example, 0.9, 0.95, 1.0, 1.05, 1.1, 1.15, 1.2, 1.25, 1. 3, 1.35, 1.4, 1.45 and 1.5 mm.

As shown in FIG. 9, when wood fibers enter a portion of the refining space 60 that is at least partially defined by the first refining grooves 28A, 38A of the first and second refining bodies 22, 32, respectively, the first and second refining bodies 22, 32 are at a distance that defines the first a gap G ₁ between the first refining plates 26A, 36A such that the refining plates 26A, 36A cooperate with each other to refine the wood fibers as described herein. When the wood fibers pass into a portion of the refining space 60 that is at least partially defined by the second refining grooves 28B, 38B of the first and second refining bodies 22, 32, respectively, the distance between the second refining plates 26B of the first refining body 22 and the second refining plates 36B of the second refining body 22 body 32 is enlarged to one of the gaps G ₄ , G ₅ or G ₆ , so that refining stops and defibration begins. We believe that the first gap G ₁ should be less than about 0.9 mm (±0.05 mm) and preferably from about 0.2 mm to about 0.9 mm (±0.05 mm) for refining to occur. This range includes all intermediate values and subranges, including, for example, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0, 6, 0.65, 0.7, 0.75, 0.8, 0.85 and 0.9 mm. In some examples, the first gap G ₁ may be from about 0.1 mm to about 0.5 mm (±0.05 mm). This range includes all intermediate values and subranges, including, for example, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45 and 0. 5 mm. In addition, the authors believe that the gaps G ₄ , G ₅ , G ₆ should be from about 0.9 mm to about 1.5 mm (±0.05 mm) for defiberation to occur. This range includes all intermediate values and subranges, including, for example, 0.9, 0.95, 1.0, 1.05, 1.1, 1.15, 1.2, 1.25, 1, 3, 1.35, 1.4, 1.45 and 1.5 mm for a range of approximately 0.9 mm to approximately 1.5 mm.

As shown in FIG. 1, 6A, 6B, 8 and 9, the gaps G ₁ and G ₂ , G ₃ , G ₄ , G ₄ , G ₅ , G ₆ , defined between the refining bodies 22, 32/132, can be adjusted by applying an axial pressure of at least at least one of the first and second refining elements 20, 30, for example, using a second motor 76, which is connected to the movable support frame 68 through a screw jack (not illustrated). For a single-disc refiner, the second refining element 30 may be attached directly to the movable support frame 68 such that the second refining element 30 moves with the movable support frame 68 when the latter is moved using the second motor 76 and the jack screw. For the double disc refiner 10, the second refining element 30 is moved as described above, i.e. when the screw jack rotates in the first direction, it causes the movable support frame 68 and the fourth refining element 50 to move inward toward the third refining element 40. The fourth refining element 50 then applies an axial force to the pulp slurry passing through the second refining space 62, which , in turn, applies an axial force to the third refining element 40, causing the third refining element 40, the support 70 and the second refining element 30 to move inward towards the first refining element 20.

The gap G ₁ defined between the refining plates 26A, 36A, 136 can be maintained at a substantially constant gap level by adjusting the position of the second refining element 30 relative to the first refining element 20 using a second motor 76 (controlled manually or through a controller/processor attached to the second motor 76) and a screw jack such that the amount of power required to be input/produced using the first motor 74 (manually controlled or via a controller/processor attached to the first motor 74) operating at a given rotation speed to process a specified amount of wood pulp flowing through the refining space 60 is maintained at a given incoming power level, which power level is observed by an operator or controller/processor that controls the first motor 74. For example, if wood pulp flows through a 20-inch diameter refining space 60 in a refiner low consistency Andritz® Twinflo IIIB at a flow rate of 151 gallons per minute, the first motor 74 is operated at a constant rotation speed of 800 rpm, the second motor 76 is adjusted to move the second refining element 30 relative to the first refining element 20 until the input power from the first motor 74 is 114 kW. When the input power from the first motor 74 is 114 kW, the gap size between the first and second refining elements 20, 30 is assumed to be 0.57 mm.

In addition, as shown in FIG. 1, 6A, 6B, 8 and 9, the authors believe that the gap G ₂ , G ₃ , G ₄ , G ₄ , G ₅ , G ₆ required to achieve defibration may vary depending on the load or flow rate (expressed in liters per minute of a suspension of fibrous mass flowing through the refining space 60), which acts on the refining bodies 22, 32/132. For example, when a slight load is applied to the refining bodies 22, 32/132, refining of the wood fibers may be stopped and defibration may begin almost immediately upon passage of the fibers into a portion of the refining space 60 that is at least partially defined by the second refining grooves 28B/28B'. 38B/38B', for example, when the wood fibers move through the first radially outer position P ₂ /P _2' and/or the third radially outer position P ₄ , as shown in FIG. 6A and 6B. When low load is applied to the refining bodies 22, 32/132, refining of the wood fibers can continue to some extent throughout at least a portion of the refining space 60, which is at least partially defined by the second refining grooves 28B/28B', 38B/38B'.

In situations in which the refining bodies 22, 32/132 are subject to high load, embodiments in which one or both of the second refining plates 26B/26B' of the first refining body 22 and the second refining plates 36B/36B' of the second refining body 32 have continuous downward slope may be particularly advantageous to ensure that sufficient spacing between the refining plates 26B/26B' and 136/36B/36B' is achieved throughout at least a portion of the refining space 60, which is at least partially defined by the second refining grooves 28B /28B', 38B/38B' to ensure that refining stops and defibration occurs. In addition, the refining surfaces 24, 34 of the refining bodies 22, 32 may be subject to wear and degradation over time. In particular, the first and third refining plates 26A/26A', 26C, 36A/36A', 36C, which perform the main high-intensity, high-energy refining, may be subject to wear faster than the second and fourth refining plates 26B/26B', 26D, 36B/36B ', 36D, which perform defibration, which is generally less intense and low in energy compared to refining. The position of the refining bodies 22, 32/132 can be adjusted as described herein to maintain the first gap G ₁ between the first and third refining plates 26A/26A', 26C, 36A/36A', 36C at a substantially constant level when the respective outer surfaces S ₂₆ a, S ₃ 6a begin to wear. However, the gap G ₂ , G ₃ , G ₄ , G ₄ , G ₅ , G ₆ between the second and fourth refining plates 26B/26B', 26D, 36B/36B', 36D cannot be adjusted. Thus, the inventors believe that embodiments in which one or both of the second refining plates 26B/26B', 36B/36B' and/or one or both of the fourth refining plates 36B/36B', 36D are inclined allow transition shift between the refining and defibration zones radially outward along the length in the longitudinal direction (not indicated; see FIGS. 6A and 6B) of the second and fourth refining plates 26B/26B', 26D, 36B/36B', 36D when the first and third ones are subject to wear refining plates 26A/26A', 26C, 36A/36A', 36C.

In fig. 10 and 11 are top views of portions of the refining surfaces of the first refining body 22' and the second refining body 32', respectively, according to another embodiment of the present invention. As shown in FIG. 1, 10, and 11, the first and second refining bodies 22', 32' may form part of refining elements, for example, first and second refining elements 20, 30, respectively, as described herein, for use in a pulp refiner such like the disc refiner 10 illustrated in FIG. 1. Each of the refining elements 20, 30, including the first and second refining bodies 22', 32', respectively, may be associated with a main support frame including a fixed support frame 66 attached to the first body section 12, and a movable support frame 68 One refining element, for example, a first refining element 20 including a first refining body 22', may be fixedly attached to the support frame 66 of the refiner 10, which defines a non-rotating stator element. Another refining element, for example, a second refining element 30 including a second refining body 32', may be fixedly attached to a support 70 that rotates with a shaft 72 and defines a rotor that is coupled to the main support frame such that rotation of the rotor produces motion second refining element 30 relative to the first refining element 20. In addition, third and fourth refining elements (not illustrated) may be present having third and fourth refining bodies similar to the first and second refining bodies 22', 32'.

As shown in FIG. 10, the first refining body 22' comprises a plurality of sections 22A'-22C that may be bolted or otherwise connected to each other to form a disc-shaped refining body 22' comprising a radially outer edge 27'. Each section 22A'-22C includes a plurality of elongated refining plates 26' separated from each other by refining grooves 28'. Although this is not shown in FIG. 10, it should be understood that other sections (not designated by numbers) of the first refining body 22' will likewise contain refining plates 26' and refining grooves 28'. The refining plates 26' extend radially outward from the radially inner position 23' towards the radially outer edge 27' of the first refining body 22'. Each section 22A'-22C of the first refining body 22' may comprise one or more radially extending sector segments comprising at least one first sector segment 22B-1 and at least one second sector segment 22B-2.

As shown in FIG. 11, the second refining body 32' comprises a corresponding plurality of sections 32A'-32C, which may be bolted or otherwise connected to each other to form a disc-shaped refining body 32' comprising a radially outer edge 37'. Each section 32A'-32C includes a plurality of elongated refining plates 36' separated from each other by refining grooves 38'. Although this is not shown in FIG. 11, it will be understood that other sections (not designated by numbers) of the second refining body 32' will likewise contain refining plates 36' and refining grooves 38'. The refining plates 36' extend radially outward from the radially inner position 33' towards the radially outer edge 37' of the second refining body 32'. Each section 32A'-32C of the second refining body 32' may include one or more radially extending sector segments comprising at least one first sector segment 32B-1 and at least one second sector segment 32B-2. Although not discussed in detail herein, the third and fourth refining bodies 42, 52 in FIG. 1 may contain a design that is substantially similar to the first and second refining bodies 22', 32', respectively, as described herein.

At least one of the first and second refining bodies 22', 32' in FIG. 10 and 11 contains one or more sections 22A'-22C, 32A'-32C containing at least one radially extending sector segment, for example, 22B-1 and 32B-1, of refining plates 26', 36', which have one or several characteristics in which they differ from the refining plates 26', 36' in the adjacent radially extending sector segment, for example, 22B-2 and 32B-2, respectively. In fig. 12A and 12B are partial cross-sectional views, with the first and second refining bodies 22', 32' in FIG. 10 and 11 are at a distance and are located close and opposite to each other (see Fig. 1). In fig. 12A, the first refining plate 26-1, which may be located on the refining surface 24-1 of at least one first sector segment 22 B-1 of the first refining body 22' (also referred to herein as the first refining surface), is located at a distance and located adjacent and opposite the third refining plate 36-1, which may be located on the refining surface 34-1 of at least one third sector segment 32B-1 of the second refining body 32' (also referred to herein as the third refining surface). In fig. 12B, a second refining plate 26-2, which may be located on the refining surface 24-2 of at least one second sector segment 22B-2 of the first refining body 22' (also referred to herein as the second refining surface), is spaced and located adjacent and opposite the fourth refining plate 36-2, which may be located on the refining surface 34-2 of at least one fourth sector segment 32B-2 of the second refining body 32' (also referred to herein as the fourth refining surface)

As shown in FIG. 10, 11 and 12A, the first refining plates 26-1 are separated from each other by the first refining grooves 28-1 and may have a first maximum height H _1' extending upward from the bottom F _1' of the corresponding adjacent first refining groove 28-1. The third refining plates 36-1 are separated from each other by third refining grooves 38-1 and may have a third maximum height H _3' extending upward from the bottom F _3' of the corresponding adjacent third refining groove 38-1. As shown in FIG. 12A, the first and third refining plates 26-1, 36-1 may be substantially similar to each other, and the first and third maximum heights H _1' , H _3' may be substantially equal.

As shown in FIG. 10, 11 and 12B, the second refining plates 26-2 are separated from each other by second refining grooves 28-2 and may have a second maximum height H _2' extending upward from the bottom F _2' of the adjacent second refining groove 28-2. The fourth refining plates 36-2 are separated from each other by fourth refining grooves 38-2 and may have a fourth maximum height H _4' extending upward from the bottom F _4' of the adjacent fourth refining groove 38-2. As shown in FIG. 12B, the second and fourth refining plates 26-2, 36-2 may be substantially similar to each other, and the second and fourth maximum heights H _2' , H _4' may be substantially equal. All of the refining plates 26-1, 26-2, 36-1, 36-2 within the corresponding sector segment 22B-1, 22B-2, 32B-1, 32B-2 may have the same height in relation to each other.

The second maximum height H _2' of the second refining plates 26-2 may be less than the first maximum height H _1' of the first refining plates 26-1. In some examples, the second maximum height H _2' , which is measured from the bottom F _2' of the adjacent second refining groove 28-2, may be at least 0.35 mm (±0.05 mm) less than the first maximum height H _1' . In other examples, the second maximum height H _2' , which is measured from the bottom F _2' of the adjacent second refining groove 28-2, may be at least 0.70 mm (±0.05 mm) less than the first maximum height H _1' . In the following examples, the first maximum height H _1' of the first refining plates 26-1, which is measured from the bottom F _1' of the corresponding adjacent first refining groove 28-1, can be from about 4 mm to about 10 mm (±0.05 mm). This range includes all intermediate values and subranges, including, for example, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8, 0, 8.5, 9.0, 9.5 and 10.0 mm. In a specific example, the second maximum height H _2' of the second refining plates 26-2, which is measured from the bottom F _2' of the corresponding adjacent second refining groove 28-2, may be less than the first maximum height H _1' , and their difference may be from approximately 0.35 mm to approximately 1.5 mm (±0.05 mm) This range includes all intermediate values and sub-ranges, including, for example, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.05, 1.1, 1, 15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45 and 1.5 mm. In another specific example, the second maximum height H _2' of the second refining plates 26-2, which is measured from the bottom F _2' of the corresponding adjacent second refining groove 28-2, may be less than the first maximum height H _1' , and their difference may be from approximately 0.7 mm to approximately 1.5 mm (±0.05 mm). This range includes all intermediate values and subranges, including, for example, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.05, 1, 1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45 and 1.5 mm. In the following examples, the first refining plates 26-1 and the second refining plates 26-2 may have a width extending between the side edges of the respective refining plates 26-1, 26-2 and ranging from about 2 mm to about 8 mm (not illustrated; see Fig. 7). This range includes all intermediate values and subranges, including, for example, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6, 0, 6.5, 7.0, 7.5 and 8.0 mm. The fourth maximum height H _4' of the fourth refining plates 36-2, to which the second maximum height H _2' may correspond, may be less than the third maximum height H _3' of the third refining plates 36-1, to which the first maximum height H _1' may correspond.

As shown in FIG. 1, 10, 11, 12A, and 12B, when the second refining element 30 is rotated relative to the first refining element 20, the refining surface 34-1 of at least one third sector segment 32B-1 of the second refining body 32' will pass the refining surface 24 -1 of at least one first sector segment 22B-1 of the first refining body 22', and the refining surface 34-2 of at least one fourth sector segment 32B-2 of the second refining body 32' will pass the refining surface 24-2 of at least one the second sector segment 22B-2 of the first refining body 22'. As the wood pulp slurry enters the frame 66, such as the inlet 16, of the refiner 10 and passes through the refining space 60, and the refining surface 34-1 of at least one third sector segment 32B-1 of the second refining body 32' passes the refining surface 24-1 of at least one first sector segment 22B-1 of the first refining body 22', the third refining plates 36-1 including the third maximum height H _3' will be located opposite the first refining plates 26-1 including the first maximum height H _1' such such that the first and third refining plates 26-1 and 36-1 refine a significant number of wood fibers. When the refining surface 34-2 of at least one fourth sector segment 32B-2 of the second refining body 32' passes the refining surface 24-2 of at least one second sector segment 22B-2 of the first refining body 22', the fourth refining plates 36-2, including the fourth maximum height H _4' will be positioned opposite the second refining plates 26-2 including the second maximum height H _2' such that the second and fourth refining plates 26-2 and 36-2 crush or separate a plurality of wood fiber bundles into wood pulp suspension as described herein. Low intensity refining can occur when the refining surface 34-1 of at least one third sector segment 32B-1 of the second refining body 32' passes the refining surface 24-2 of at least one second sector segment 22B-2 of the first refining body 22', and the refining the surface 34-2 of at least one fourth sector segment 32B-2 of the second refining body 32' extends through the refining surface 24-1 of at least one first sector segment 22B-1 of the first refining body 22'.

As shown in FIG. 10 and 11, one or each of several sections 22A'-22C, 32A'-32C of respective refining bodies 22', 32' may, in some examples, comprise three radially extending sector segments 22B-1, 22B-1, 22B-3 and 32B -1, 32V-2, 32V-3. In some specific examples, two segments, for example, 22B-1, 22B-3 and 32B-1, 32B-3, may contain refining plates with one of the first and second maximum heights H _1' , H _2' , and one segment, for example , 22B-2 and 32B-2, may contain refining plates with the other of the first and second maximum heights H _1' , H _2' , and the second maximum height H _2' is less than the first maximum height H _1' . For example, segments 22B-1, 22B-3 may contain first refining plates 26-1, segments 32B-1, 32B-3 may contain third refining plates 36-1, segment 22B-2 may contain second refining plates 26-2, and segment 32B-2 may include fourth refining plates 36-2. In other examples (not illustrated), one or each of several sections 22A'-22C, 32A'-32C may contain only two refining plate segments or may contain four or more refining plate segments. In the following examples (not illustrated), one or more sections 22A'-22C, 32A'-32C may not include individual segments such that the entire section contains refining plates of the same height. It should be understood that the refining body according to the present invention, for example, one of the refining bodies 22', 32', can be paired with a refining body including conventional refining plates, for example, refining plates, all of which have the same height.

We believe that the gap between the opposing first and third refining plates 26-1, 36-1 should be less than about 0.9 mm (±0.05 mm) and preferably from about 0.2 mm to about 0.9 mm ( ±0.05 mm) for refining to occur, and that the gap between the opposing second and fourth refining plates 26-2, 36-2 should be from about 0.9 mm to about 1.5 mm (±0.05 mm), for defibre to occur. Each of the specified ranges includes all intermediate values and subranges, including, for example, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85 and 0.9 mm for the range from approximately 0.2 mm to approximately 0.9 mm, and 0.9, 0. 95, 1.0, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45 and 1.5 mm for a range of approx. 0.9 mm to approximately 1.5 mm. In some examples, the gap between the opposing first and third refining plates 26-1, 36-1 may be from about 0.1 mm to about 0.5 mm (±0.05 mm). This range includes all intermediate values and subranges, including, for example, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45 and 0. 5 mm.

In fig. 19A and 19B are partial sectional views similar to FIGS. 6A and 6B for first refining bodies 1022, 1022' having a corresponding first refining surface 1024, 1024', and second refining bodies 1032, 1032' having a corresponding second refining surface 1034, 1034'. As described in detail herein, the first and second refining bodies 1022/1022', 1032/1032' may form part of refining elements, such as refining elements 20, 30, respectively, in FIG. 1, for use in a pulp refiner such as the disk refiner 10 illustrated in FIG. 1. Each of the refining elements 20, 30, containing the first and second refining bodies 1022/1022', 1032/1032', can be connected to a main support frame containing a fixed support frame 66 attached to the first body section 12, and a movable support frame frame 68. One refining element, for example, a first refining element 20 comprising a first refining body 1022/1022A', may be fixedly attached to the support frame 66 of the refiner 10, defining a non-rotating stator element. Another refining element, for example, a second refining element 30 containing a second refining body 1032/1032', can be fixedly attached to a support 70, which rotates with the shaft 72 and defines a rotor that is connected to the main support frame, such that when rotated The rotor causes movement of the second refining element 30 relative to the first refining element 20. Each of the first and second refining bodies 1022/1022', 1032/1032' may contain a plurality of sections (not illustrated; see 22A-22C and 32A-32C in FIG. 2 and 3), which may be bolted or otherwise connected to each other to form a disc-shaped refining body comprising a corresponding radially inner edge 1023, 1023' and 1033, 1033' and a radially outer edge 1027, 1027' and 1037. , 1037'.

As shown in FIG. 19A, each of the refining surfaces 1024, 1034 may include a plurality of elongated refining plates 1026, 1036 containing first refining plates 1026A, 1036A and second refining plates 1026B, 1036B that separate respective first refining grooves 1028A, 1 038A and second refining grooves 1028B, 1038B (first and second refining plates 1026A/1036A and 1026B/1036B may also be referred to herein as the first and second refining plate elements). In some examples, the first and second refining grooves 1028A, 1028B and 1038A, 1038B may have a width (not shown; see _WG in FIGS. 4A and 5A) ranging from about 2.0 mm to about 6.0 mm, and the first and second refining plates 1026A, 1026B and 1036A and 1036B may have a width (not shown; see W ₂₆ in FIG. 7) ranging from about 2.0 mm to about 8.0 mm. Each of the specified ranges includes all intermediate values and subranges, including, for example, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5 and 6.0 mm for the range from approximately 2.0 mm to approximately 6.0 mm, and 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5, 5, 6.0, 6.5, 7.0, 7.5 and 8.0 mm for a range of approximately 2.0 mm to approximately 8.0 mm. The refining plates 1026, 1036 may be inclined at various angles on the respective refining surfaces 1024, 1034, and each section of the refining body 1022, 1032 may include one or more segments (not designated) of refining plates 1026, 1036 that are inclined in different directions (not presented; see Figs. 2 and 3).

Each of the first and second refining plates 1026, 1036 extend radially outward from a radially inner position being a radially inner edge 1023, 1033 to a radially outer edge 1027, 1037 of the corresponding refining body 1022, 1032. In particular, each of the first refining plates 1026A , 1036A extends from a first radially inward position P ₁₀₀₀ on the refining surface 1024, 1034 to a first radially outer position P ₂₀₀₀ on the refining surface 1024, 1034. Each of the second refining plates 1026B, 1036B extends from a second radially inward position on the refining surface 1024, 1034 as described herein, to a second radially outer position P ₃₀₀₀ on the refining surface 1024, 1034, wherein the second radially outer position P ₃₀₀₀ may be closer to the outermost portion of the refining body 1022, 1032, such as the radially outer edge 1027, 1037, in the general direction of movement of the wood fibers than the first radially outer position P ₂₀₀₀ . In some examples, the first radially inboard position P ₁₀₀₀ may be a position located exactly or approximately on the radially inboard edge 1023, 1033. In some embodiments, the second refining plates 1026B, 1036B may be integral with the first refining plates 1026A, 1036A, such that that the second radially inward position of the second refining plates 1026B, 1036B is substantially the same as the first radially outer position P ₂₀₀₀ of the first refining plates 1026A, 1036A, and the second refining plates 1026B, 1036B extend from the first radially outer position P ₂₀₀₀ to the second radially outer position position P3 ₀₀₀ . In other embodiments (not shown), the first refining plates 1026A, 1036A may be radially spaced from the second refining plates 1026B, 1036B. The second refining plates 1026B, 1036B may have a longitudinal length L ₁₀₀₀ ranging from about 0.6 cm to about 10 cm, and preferably from about 2 cm to about 10 cm. As described above, the refining surfaces 1024, 1034 may include partitions ( not shown; see 29 and 39 in FIGS. 4A, 5A and 7), located in at least some of the first refining grooves 1028A, 1038A, and the partitions may have a height that is substantially the same as or less than the height of the adjacent first ones. refining plates 1026A, 1036A.

In addition, as shown in FIG. 19A, the first refining plates 1026A, 1036A have a first height H ₁₀₀₀ extending upward from the bottom F ₁₀₀₀ of the adjacent first refining groove 1028A, 1038A. In some examples, the first height H ₁₀₀₀ may represent the maximum height of the first refining plates 1026A, 1036A. The first refining plates 1026A, 1036A may extend substantially horizontally such that the first height H ₁₀₀₀ may be substantially constant in the longitudinal direction throughout the (not indicated) first refining plates 1026A, 1036A, for example, between the first radially inward position P ₁₀₀₀ and the first radially outer position P ₂₀₀₀ , as shown in the example in FIG. 19A. In some examples, the first height H ₁₀₀₀ of the first refining plates 1026A, 1036A, when measured from the bottom F ₁₀₀₀ of the adjacent first refining groove 1028A, 1038A, can be from about 4.0 mm to about 10.0 mm (±0.5 mm). This range includes all intermediate values and subranges, including, for example, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8, 0, 8.5, 9.0, 9.5 and 10.0 mm.

The second refining plates 1026B, 1036B have a second height H ₂₀₀₀ extending upward from the bottom F ₂₀₀₀ of the adjacent second refining groove 1028B, 1038B, the second height H ₂₀₀₀ being the minimum height of the second refining plates 1026B, 1036B and spaced from the second radially inward position , for example, P ₂₀₀₀ , second refining plates 1026B and 1036B (the first and second heights H ₁₀₀₀ , H ₂₀₀₀ may also be referred to herein as the first and second refining plate heights). In some embodiments, the second height H ₂₀₀₀ of the second refining plates 1026B, 1036B extending upward from the bottom F ₂₀₀₀ of the adjacent second refining groove 1028B, 1038B may be greater than zero, as represented by the solid line in FIG. 19A. For example, the second height H ₂₀₀₀ may be from about 2.0 mm to about 4.0 mm (±0.2 mm). This range includes all intermediate values and subranges, including, for example, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3, 6, 3.8 and 4.0 mm. In other embodiments, the second height H ₂₀₀₀ may be slightly greater than zero, for example, the second refining plates 1026B, 1036B, at their minimum height, may be slightly above or flush with the bottom F ₂₀₀₀ of the adjacent second refining groove 1028B, 1038B, as represented by the dashed line. line in Fig. 19A.

The second height H ₂₀₀₀ of the second refining plates 1026B, 1036B may be at least about 0.35 mm (±0.05 mm) less than the first height H ₁₀₀₀ of the first refining plates 1026A, 1036A. In some examples, the second height H ₂₀₀₀ may be at least 0.7 mm (±0.05 mm) less than the first height H ₁₀₀₀ . In some specific examples, the second height H ₂₀₀₀ of the second refining plates 1026B, 1036B, when measured from the bottom F ₂₀₀₀ of the adjacent second refining groove 1028B, 1038B, can be from about 0.35 mm to about 7.0 mm (±0.05 mm) less than the first height H ₁₀₀₀ . This range includes all intermediate values and subranges, including, for example, 0.35, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4, 0, 4.5, 5.0, 5.5, 6.0, 6.5 and 7.0 mm. In other specific examples, the second height H ₂₀₀₀ may be less than the first height H ₁₀₀₀ , the difference being between about 0.7 mm and about 7.0 mm (±0.05 mm). This range includes all intermediate values and subranges, including, for example, 0.7, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4, 5, 5.0, 5.5, 6.0, 6.5 and 7.0 mm. In the following specific examples, the second height H ₂₀₀₀ may be from about 0.7 mm to about 5.0 mm (±0.05 mm) less than the first height H ₁₀₀₀ , or from about 2.0 mm to about 3.0 mm ( ±0.05 mm) less than the first height H ₁₀₀₀ . Each of the specified ranges includes all intermediate values and subranges, including, for example, 0.7, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5 and 4.5 mm for the range from approximately 0.7 mm to approximately 5.0 mm, and 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2, 6, 2.7, 2.8, 2.9 and 3.0 mm for the range from approximately 2.0 mm to approximately 3.0 mm. In embodiments in which the second height H ₂₀₀₀ is slightly greater than zero, the difference between the first and second heights H ₁₀₀₀ , H ₂₀₀₀ may represent substantially the full height of the first refining plates 1026A, 1036A. For example, when the first height H ₁₀₀₀ of the first refining plates 1026A, 1036A is approximately 10.0 mm, the second height H ₂₀₀₀ of the second refining plates 1026B, 1036B may be approximately 10.0 mm less than the first height H ₁₀₀₀ .

As shown in FIG. 19A, in some examples, the second refining plates 1026B, 1036B may have a substantially continuous downward slope over at least a portion of each of the second refining plates 1026B, 1036B extending between a first radially outer position P ₂₀₀₀ to a second radially outer position P ₃₀₀₀ . In some specific examples, the height of the second refining plates 1026B, 1036B may be continuously reduced over substantially the entire length in the longitudinal direction L ₁₀₀₀ of the second refining plates 1026B, 1036B. For example, the second refining plates 1026B, 1036B may have a maximum height (not specifically designated) that is at a position near the first radially outer position P ₂₀₀₀ and which is substantially the same as the first height H ₁₀₀₀ of the first refining plates 1026A, 1036A. wherein the second refining plates 1026B, 1036B have a substantially continuous downward slope from a first radially outer position P ₂₀₀₀ to a second radially outer position P ₃₀₀₀ . The second (minimum) height H ₂₀₀₀ of the second refining plates 1026B, 1036B may be present at a position that is adjacent to the second radially outer position P ₃₀₀₀ .

In some examples, first and second refining elements 20, 30 containing first and second refining bodies 1022, 1032 may be arranged such that the first refining surface 1024 faces the second refining surface 1034 (not shown; see, for example, FIG. 1, 8 and 9), with the first refining element 20 spaced from the second refining element 30 defining a refining space (see 60 in FIG. 1) between the respective refining surfaces 1024, 1034, as described in detail herein. At least some of the refining plates 1026 of the first refining body 1022 may be positioned to be opposite, i.e. face at least some of the refining plates 1036 of the second refining body 1032, defining a gap (see FIGS. 8 and 9) between opposing portions of the refining plates 1026, 1036. In particular, at least some of the first refining plates 1026A of the first refining body 1036 bodies 1022 can be positioned to be opposite, i.e. face at least some of the first refining plates 1036A of the second refining body 1032, and at least some of the second refining plates 1026B of the first refining body 1022 may be positioned to face, i.e. be facing at least some of the second refining plates 1036B of the second refining body 1032.

When the wood pulp slurry containing wood fibers enters the frame 66 of the refiner 10, as shown in FIG. 1 and described above, an axial force or pressure may be applied to one or both of the refining elements 20, 30 to adjust the size of the gap defined between the first and second refining elements 20, 30. The first refining plates 1026A, 1036A may be configured refining the wood fibers into a pulp slurry, while the second refining plates 1026B, 1036B may be configured to crush or separate the fiber bundles. Because the first height H ₁₀₀₀ of the first refining plates 1026A, 1036A is greater than the second height H ₂₀₀₀ of the second refining plates 1026B, 1036B, the wood fibers are subject to high-intensity shear and compression forces as the fibers pass through a portion of the refining space that is at least partially defined by the first refining grooves 1028A, 1038A (eg, refining zone as described above). The first refining plates 1026A, 1036A cooperate with each other or with conventional refining plates to refin a significant amount of wood fibers into wood pulp. As the fibers pass into a portion of the refining space that is at least partially defined by the second refining grooves 1028B, 1038B (e.g., the de-fiber zone as described above), the intensity of the force applied to the fibers decreases in response to the decrease in height, resulting in, as According to the authors, the plurality of bundles of wood fibers that are formed during refining are crushed or separated, without additional refining or with only minimal refining of the fibers.

In this example, the gap between opposing portions of the second refining plates 1026B, 1036B may range from about 0.9 mm to about 20.0 mm (±0.05 mm). This range includes all intermediate values and subranges, including, for example, 0.9, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4, 5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5, 12.0, 12.5, 13.0, 13.5, 14.0, 14.5, 15.0, 15.5, 16.0, 16.5, 17, 0, 17.5, 18.0, 18.5, 19.0, 19.5 and 20.0 mm. In embodiments in which the second refining plates 1026B and/or 1036B are sloped downward substantially continuously over at least a portion of the second refining plate 1026B, 1036B, the gap may increase over at least a section of the second refining plates 1026B, 1036B in a radially outward direction. , i.e. in a direction extending from a second radially inner position (eg, P ₂₀₀₀ ) to a second radially outer position P ₃₀₀₀ of the second refining plates 1026B, 1036B. In some examples, the gap may increase over substantially the entire length in the longitudinal direction L ₁₀₀₀ of the second refining plates 1026B, 1036B. The authors believe that the second (minimum) height H ₂₀₀₀ of the second refining plates 1026B, 1036B should be at least about 0.35 mm (±0.05 mm) less than the first height H ₁₀₀₀ of the first refining plates 1026A, 1036A in order to stop refining of fibers and beginning of defibration.

In other examples, one of the refining bodies 1022, 1032, which are shown in FIG. 19A may be paired with a conventional refining body (not shown; see 132 in FIG. 8) that contains conventional refining plates having a uniform height throughout substantially their entire longitudinal extent. For example, the first refining element may include a first refining body 1022, and the second refining element 30 may include a conventional refining body. The refining elements 20, 30 may be arranged so that they face each other, with at least some of the first and second refining plates 1026A, 1026B being arranged so that they are opposite, i.e. facing at least some of the conventional refining plates, defining a gap (see FIGS. 8 and 9) between the opposing portions. As described herein, a slurry of wood fiber may be supplied and an axial force or pressure may be applied to one or both of the refining elements 20, 30 to control the size of the gap, the first refining plates 1026A being configured to refin the wood fibers in the slurry mass, and the second refining plates 1026B are configured to grind or separate the fiber bundles. In this example, the gap between the opposing portions of the second refining plates 1026B and the conventional refining plates may range from about 0.9 mm to about 10.0 mm (±0.05 mm). This range includes all intermediate values and subranges, including, for example, 0.9, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4, 5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5 and 10.0 mm. In embodiments in which the second refining plates 1026B are inclined, the gap may increase over at least a section of the second refining plates 1026B in a radial outward direction as described herein, and may increase over substantially the entire length in the longitudinal direction L ₁₀₀₀ second refining plates 1026B. In this example, the inventors believe that the second (minimum) height H ₂₀₀₀ of the second refining plates 1026B should be at least about 0.7 mm less (±0.05 mm) than the first height H ₁₀₀₀ of the first refining plates 1026A/1036A for purposes of the cessation of fiber refining and the beginning of defibration.

In both examples, the inventors believe that the gap between opposing portions of the refining plates must be less than about 0.9 mm (±0.05 mm) for purposes of refining (e.g., between opposing portions of the first refining plates 1026A, 1036A, or between opposing portions of the first refining plates 1026A/1036A and traditional refining plates). In some cases, the clearance in the refining zone may be less than about 0.7 mm (±0.05 mm). In some specific cases, the gap may be from about 0.1 mm to about 0.5 mm (±0.05 mm). This range includes all intermediate values and subranges, including, for example, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45 and 0. 5 mm. In addition, the inventors believe that the gap should be from about 0.9 mm to about 2.0 mm (±0.05 mm) for the purpose of defibration (for example, between opposing parts of the second refining plates 1026B, 1036B or between opposing parts of the second refining plates 1026B/1036B and traditional refining plates). This range includes all intermediate values and subranges, including, for example, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1, 7, 1.8, 1.9 and 2.0 mm. As noted above, the gap along at least a portion of the second refining plates 1026B/1036B may be significantly more than about 2.0 mm, such as up to about 20.0 mm in some cases. This increased clearance can be used to compensate for the inevitable wear, due to which the heights H ₁₀₀₀ , H ₂₀₀₀ of the refining plates 1026A, 1036A, 1026B, 1036B are reduced. The position of the refining bodies can be adjusted as described herein to maintain the clearance at a desired level when the refining surfaces begin to wear. In particular embodiments in which the second refining plates 1026B, 1036B are inclined downward substantially continuously over at least a portion of each of the second refining plates 1026B, 1036B, we consider it acceptable to shift the transition between the refining and defibrification zones radially outward in the longitudinal direction along the length L ₁₀₀₀ second refining plates 1026B, 1036B, such that a gap of about 0.9 mm to about 2.0 mm for defibration can be maintained during the life of the refining elements.

As shown in FIG. 19V, refining bodies 1022 ', 1032' can have the appropriate refining surfaces 1024 ', 1034', each of which contains many oblong refineries 1026 ', 1036', containing the first refining plates 1026a ', 1036A', the second refining plates 1026V ',, the second refining plates, 1036B', third refining plates 1026C, 1036C and fourth refining plates 1026D, 1036D. The first and second refining plates 1026A', 1036A', 1026B', 1036B' may be substantially similar to the first and second refining plates 1026A, 1036A, 1026B, 1036B as illustrated in FIG. 19A and described herein. The first refining plates 1026A', 1036A' may be separated from each other by the first refining grooves 1028A', 1038A', and the second refining plates 1026B', 1036B' may be separated from each other by the second refining grooves 1028B', 1038B'. The third refining plates 1026C, 1036C may be separated from each other by third refining grooves 1028C, 1038C, and the fourth refining plates 1026D, 1036D may be separated from each other by fourth refining grooves 1028D, 1038D.

Each of the first refining plates 1026A', 1036A' may extend from a first radially inward position P _1000' to a first radially outer position P _2000' on the refining surface 1024', 1034'. Each of the second refining plates 1026B', 1036B' may extend from a second radially inward position on the refining surface 1024', 1034', as described herein, to a second radially outer position P ₃₀₀₀ on the refining surface 1024', 1034'. Each of the third refining plates 1026C, 1036C may extend from a third radially inward position on the refining surface 1024', 1034', as described herein, to a third radially outer position P ₄₀₀₀ on the refining surface 1024', 1034'. Each of the fourth refining plates 1026D, 1036D may extend from a fourth radially inward position on the refining surface 1024', 1034', as described herein, to a fourth radially outer position P ₅₀₀₀ on the refining surface 1024', 1034'. The fourth radially outer position P ₅₀₀₀ may be closer to the outermost portion, for example, the radially outer edge 1027', 1037', of the refining body 1022', 1032' than the first, second and third radially outer positions P _3000' , P ₃₀₀₀ and R ₄₀₀₀ . The second and fourth refining plates 1026B/1036B' and 1026D/1036D may have a corresponding length in the longitudinal direction L ₁₀₀₀ , L ₂₀₀₀ ranging from about 0.6 cm to about 10 cm and preferably from about 2 cm to about 10 cm. In some In examples, the first and/or second refining plates 1026A', 1036A', 1026B', 1036B' may extend radially outward a shorter distance compared to the first and second refining plates 1026A, 1036A, 1026B, 1036B. As described above, the refining surfaces 1024', 1034' may include baffles (not shown; see 29 and 39 in FIGS. 4B and 5B) that are present in at least some of the first and third refining grooves 1028A/1038A' and 1028C /1038C, and these partitions may have a height that is substantially the same as or greater than the height of the adjacent first and/or third refining plates 1026A/1036A' and 1026C/1036C.

According to some embodiments, as illustrated in FIG. 19B, the second refining plates 1026B', 1036B' may be integral with the first refining plates 1026A', 1036A'; the third refining plates 1026C, 1036C may be integral with the second refining plates 1026B', 1036B'; and/or the fourth refining plates 1026D, 1036D may be integral with the third refining plates 1026C, 1036C. For example, when the first and second refining plates 1026A/1036A' and 1026B/1036B' are integral with each other, the second radially inward position of the second refining plates 1026B', 1036B' may be substantially the same as the first radially outer position P _2000' the first refining plates 1026A', 1036A', and the second refining plates 1026B', 1036B' may extend from a first radially outer position P _2000' to a second radially outer position P _3000' . When the second and third refining plates 1026B/1036B' and 1026C/1036C are integral with each other, the third radially inward position of the third refining plates 1026C, 1036C may be substantially the same as the second radial outer position P ₃₀₀₀ of the second refining plates 1026B', 1036B', and third refining plates 1026C, 1036C may extend from a second radially outer position P ₃₀₀₀ to a third radially outer position P ₄₀₀₀ . When the third and fourth refining plates 1026C/1036C and 1026D/1036D are integral with each other, the fourth radially inward position of the fourth refining plates 1026D, 1036D may be substantially the same as the third radial outer position P ₄₀₀₀ of the third refining plates 1026C, 1036C, and fourth refining plates 1026D, 1036D may extend from a third radially outer position P ₄₀₀₀ to a fourth radially outer position P ₅₀₀₀ . In other embodiments (not shown), the first refining plates 1026A', 1036A' may be radially spaced from the second refining plates 1026B', 1036B', the second refining plates 1026B', 1036B' may be radially spaced from the third refining plates 1026C, 1036C, and/or third refining plates 1026C, 1036C may be radially spaced from the fourth refining plates 1026D, 1036D.

In addition, as shown in FIG. 19B, the first and third refining plates 1026A/1036A' and 1026C/1036C have a corresponding first height H _1000' and a third height H ₃₀₀₀ extending upward from the bottom F _1000' , F ₃₀₀₀ of the respective adjacent first and third refining grooves 1028A/1038A' and 1028С/1038С. The first and third heights H _1000' , H ₃₀₀₀ may represent the maximum height of the first and third refining plates 1026A/1036A' and 1026C/1036C, respectively. In some examples, the first and third refining plates 1026A/1036A' and 1026C/1036C may extend substantially horizontally such that the first and third heights H ₁₀₀₀ , H ₃₀₀₀ may be substantially constant in the longitudinal direction throughout the (not indicated) first and third refining plates. plates 1026A/1036A' and 1026C/1036C, for example, between the first radially inner position P ₁₀₀₀ and the first radially outer position P _2000' for the first refining plates 1026A', 1036A' and between the third radially inner position, for example P3000 and the third radially outer position P ₄₀₀₀ for the third refining plates 1026С, 1036С. In some examples, the first and third heights H ₁₀₀₀ , H ₃₀₀₀ of the first and third refining plates 1026A/1036A' and 1026C/1036C, when measured from the bottom F _1000' , F ₃₀₀₀ of the corresponding adjacent first and third refining grooves 1028A/1038A' and 1028C/ 1038C may range from about 4.0 mm to about 10.0 mm (±0.5 mm). This range includes all intermediate values and subranges, including, for example, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8, 0, 8.5, 9.0, 9.5 and 10.0 mm.

The second and fourth refining plates 1026B/1036B' and 1026D/1036D may have, respectively, a second height H _2000' and a fourth height H ₄₀₀₀ extending upward from the bottom F _2000' , F ₄₀₀₀ of the respective adjacent second and fourth refining grooves 1028B/1038B' and 1028D/1038D. The second height H _2000' represents the minimum height of the second refining plates 1026B', 1036B' and is spaced from a second radially inward position, eg P _2000' , of the second refining plates 1026B', 1036B'. The fourth height H ₄₀₀₀ represents the minimum height of the fourth refining plates 1026D, 1036D and is located at a distance from the fourth radially inward position, eg P ₄₀₀₀ , of the fourth refining plates 1026D, 1036D. According to some embodiments, a second height H _2000' of the second refining plates 1026B', 1036B' extending upward from the bottom F _2000' of the adjacent second refining groove 1028B', 1038B' and/or a fourth height H ₄₀₀₀ of the fourth refining plates 1026D, 1036D extending up from the bottom F ₄₀₀₀ of the adjacent fourth refining groove 1028D, 1038D, may be more than zero, as represented by the solid line in FIG. 19V. For example, the second height H _2000' and/or the fourth height H ₄₀₀₀ may be from about 2.0 mm to about 4.0 mm (±0.2 mm). This range includes all intermediate values and subranges, including, for example, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3, 6, 3.8, and 4.0 mm. According to other embodiments, the second height H _2000' and/or the fourth height H ₄₀₀₀ may be slightly greater than zero, for example, the second refining plates 1026B', 1036B' and/or the fourth refining plates 1026D, 1036D may be slightly higher at their minimum height level or flush with the bottom F _2000' , F ₄₀₀₀ of the respective adjacent second or fourth refining grooves 1028B/1038B', 1028D/1038D, as represented by the dashed line in FIG. 19V.

The second height H _2000' of the second refining plates 1026B', 1036B' and/or the fourth height H ₄₀₀₀ of the fourth refining plates 1026D, 1036D may be at least about 0.35 mm (±0.05 mm) less than the first height H ₁₀₀₀ the first refining plates 1026A', 1036A' and/or the third height H ₃₀₀₀ of the third refining plates 1026C, 1036C, respectively. In some examples, the second height H _2000' and the fourth height H ₄₀₀₀ may be at least 0.70 mm (±0.05 mm) less than the first height H _1000' and the third height H ₃₀₀₀ , respectively. In some specific examples, the second height H _2000' of the second refining plates 1026B', 1036B', when measured from the bottom F _2000' of the adjacent second refining groove 1028B', 1038B', and/or the fourth height H4 ₄₀₀₀ of the fourth refining plates 1026D, 1036D, at measured from the bottom F ₄₀₀₀ of the adjacent fourth refining groove 1028D, 1038D, may be about 0.35 mm to about 7.0 mm (±0.05 mm) less than the first height H ₁₀₀₀ and the third height H ₃₀₀₀ , respectively. This range includes all intermediate values and subranges, including, for example, 0.35, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4, 0, 4.5, 5.0, 5.5, 6.0, 6.5 and 7.0 mm. In other specific examples, the second height H _2000' and the fourth height H ₄₀₀₀ may be less than the first height H ₁₀₀₀ and the third height H ₃₀₀₀ , respectively, the difference being from about 0.7 mm to about 7.0 mm (±0.05 mm). This range includes all intermediate values and subranges, including, for example, 0.7, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4, 5, 5.0, 5.5, 6.0, 6.5 and 7.0 mm. In the following specific examples, the second height H _2000' and the fourth height H ₄₀₀₀ may be less than the first height H ₁₀₀₀ and the third height H ₃₀₀₀ , respectively, the difference being from about 0.7 mm to about 5.0 mm (±0.05 mm), or less than the first height H ₁₀₀₀ and the third height H ₃₀₀₀ , respectively, the difference being from about 2.0 mm to about 3.0 mm (±0.05 mm). Each of the specified ranges includes all intermediate values and subranges, including, for example, 0.7, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5 and 4.5 mm for the range from approximately 0.7 mm to approximately 5.0 mm, and 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2, 6, 2.7, 2.8, 2.9, and 3.0 mm for the range from about 2.0 mm to about 3.0 mm. According to embodiments in which the second and/or fourth heights H _2000' , H ₄₀₀₀ are slightly greater than zero, the difference between the first and second heights H _1000' , H _2000' and/or between the third and fourth heights H ₃₀₀₀ , H ₄₀₀₀ may represent substantially the entire height of the first and/or third refining plates 1026A/1036A' and 1026C/1036C. For example, when the first and third heights H _1000' , H ₃₀₀₀ are approximately 10.0 mm, the second and fourth heights H _2000' , H ₄₀₀₀ may be approximately 10.0 mm less than the first and third heights H _1000' , H ₃₀₀₀ .

As shown in FIG. 19B, in some examples, the second refining plates 1026B', 1036B' and/or the fourth refining plates 1026D, 1036D may have a substantially continuous downward slope over at least a portion of each refining plate 1026B', 1036B', 1026D, 1036D. For example, the second refining plates 1026B', 1036B' may have a substantially continuous downward slope over at least a portion extending from the first radially outer position P _2000' to the second radially outer position P ₃₀₀₀ , and/or the fourth refining plates 1026D, 1036D may have a substantially continuous downward slope over at least a portion extending from the third radially outer position P ₄₀₀₀ to the fourth radially outer position P ₅₀₀₀ . In some specific examples, the height of the second refining plates 1026B', 1036B' and/or the fourth refining plates 1026D, 1036D may be continuously reduced over substantially their respective longitudinal lengths L _1000' , L ₂₀₀₀ . For example, the second refining plates 1026B', 1036B' may have a maximum height (not specifically designated) that is present at a position proximate the first radially outer position P _2000' and which is substantially the same as the first height H _1000' of the first refining plates 1026A', 1036A', the second refining plates 1026B', 1036B' having a substantially continuous downward slope from a first radially outer position P _2000' to a second radially outer position P _3000' . The fourth refining plates 1026D, 1036D may similarly have a maximum height (not specifically designated) that is present at a position proximate to the third radially outer position P ₄₀₀₀ and which is substantially the same as the third height H ₃₀₀₀ of the third refining plates. 1026C, 1036C, with the fourth refining plates 1026D, 1036D having a substantially continuous downward slope from a third radially outer position P _4000' to a fourth radially outer position P _5000' . A second (minimum) height H _2000' of the second refining plates 1026B', 1036B' may be present at a position that is proximate to the second radially outer position P _3000' , and a fourth (minimum) height H ₄₀₀₀ of the fourth refining plates 1026D, 1036D may be present at a position , which is near the fourth radially outer position P ₅₀₀₀ .

In some examples, the first and second refining elements 20, 30 containing the first and second refining bodies 1022', 1032' may be arranged such that the first and second refining surfaces 1024', 1034' face each other (not shown; see ., for example, Fig. 1, 8, and 9), defining the refining space (see 60 in Fig. 1), as described in detail herein. At least some of the refining plates 1026' of the first refining body 1022' are arranged so that they are opposite, i.e. face at least some of the refining plates 1036' of the second refining body 1032', defining a gap (see FIGS. 8 and 9) between opposing portions of the refining plates 1026', 1036'. In particular, at least some of the first refining plates 1026A' of the first refining body 1022' may be arranged so that they are opposite, i.e. facing at least some of the first refining plates 1036A' of the second refining body 1032'; at least some of the second refining plates 1026B' may be arranged so that they are opposite, i.e. facing at least some of the second refining plates 1036B'; at least some of the third refining plates 1026C may be positioned so that they are opposite, i.e. facing at least some of the third refining plates 1036C; and at least some of the fourth refining plates 1026D may be arranged so that they are opposite, i.e. facing at least some of the fourth refining plates 1036D.

When the wood pulp slurry containing wood fibers enters the frame 66 of the refiner 10, as shown in FIG. 1 and described above, an axial force or pressure can be applied to one or both of the refining elements 20, 30, and the size of the gap that is defined between the first and second refining elements 20, 30 can be adjusted. The first and third refining plates 1026A/ 1036A' and 1026C/1036C may be configured to refin the wood fibers into a pulp slurry, while the second and fourth refining plates 1026B/1036B' and 1026D/1036D may be configured to crush or separate fiber bundles. Since the first and third heights H _1000' and H ₃₀₀₀ of the first and third refining plates 1026A/1036A' and 1026C/1036C are more than the corresponding second and fourth heights H _2000' and H ₄₀₀₀ of the second and fourth refining plates 1026B/1036B' and 1026D/ 1036D, the wood fibers are subjected to high-intensity shear and compression forces as the fibers pass through a portion of the refining space that is at least partially defined by the first and third refining grooves 1028A/1038A' and 1028C/1038C (e.g., the first and second refining zones as described higher). The first and third refining plates 1026A/1036A' and 1026C/1036C cooperate with each other to refin a significant number of wood fibers into the wood pulp. As the fibers extend into a portion of the refining space that is at least partially defined by the second and fourth refining grooves 1028B/1038B' and 1028D/1038D (e.g., the first and second de-fiber zones as described above), the intensity of the force that is applied to the fibers is reduced. in response to the reduction in height, and the authors believe that this occurs by shredding or separating the plurality of bundles of wood fibers that are formed during refining, without additional refining or with only minimal refining of the fibers.

In this example, the gap between the opposing portions of the second refining plates 1026B', 1036B' and between the opposing portions of the fourth refining plates 1026D, 1036D may range from about 0.9 mm to about 20.0 mm (±0.05 mm). This range includes all intermediate values and subranges, including, for example, 0.9, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4, 5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5, 12.0, 12.5, 13.0, 13.5, 14.0, 14.5, 15.0, 15.5, 16.0, 16.5, 17, 0, 17.5, 18.0, 18.5, 19.0, 19.5 and 20.0 mm. In examples in which one or more of the second and fourth refining plates 1026B/1036B' and 1026D/1036D have a substantially continuous downward slope over at least a portion, the gap may increase over at least a section of the second refining plate 1026B', 1036B ' in the radial direction outwards, i.e. in a direction extending from a second radially inboard position (e.g., P _2000' ) to a second radially outer position P ₃₀₀₀ of the second refining plates 1026B', 1036B', and/or the gap may increase over at least a section of the fourth refining plate 1026D, 1036D in the radial direction outwards, i.e. in a direction extending from the fourth radially inner position (eg, P ₄₀₀₀ ) to the fourth radially outer position P ₅₀₀₀ of the fourth refining plates 1026D, 1036D. In some examples, the gap may increase over substantially the entire longitudinal length L ₁₀₀₀ and/or L ₂₀₀₀ of the second and/or fourth refining plates 1026B/1036B' and 1026D/1036D, respectively. The authors believe that in order to stop fiber refining and begin defibration, the second (minimum) height H _2000' of the second refining plates 1026B', 1036B' and the fourth (minimum) height H ₄₀₀₀ of the fourth refining plates 1026D, 1036D should be at least approximately 0.35 mm (±0.05 mm) less than the first height H ₁₀₀₀ of the first refining plates 1026A', 1036A' and the third height H ₃₀₀₀ of the third refining plates 1026C, 1036C, respectively.

In other examples, one of the refining bodies 1022', 1032', which are shown in FIG. 19B may be paired with a conventional refining body (not shown; see 132 in FIG. 8) which contains refining plates having the same height throughout substantially their entire length in the longitudinal direction. For example, the first refining element 20 may include a first refining body 1022', and the second refining element 30 may include a conventional refining body. The refining elements 20, 30 may be arranged to face each other, with at least some of the first, second, third and fourth refining plates 1026A', 1026B', 1026C, 1026D being arranged to face each other , i.e. facing at least some of the conventional refining plates, defining a gap (see FIGS. 8 and 9) between the opposing portions. As described herein, a slurry of wood pulp is supplied and an axial force or pressure may be applied to one or both of the refining elements 20, 30 to control the size of the gap, the first and third refining plates 1026A', 1026C being refinable wood fibers in a pulp suspension, and wherein the second and fourth refining plates 1026B', 1026D are configured to crush or separate the fiber bundles. In this example, the gap between the opposing portions of the conventional refining plates and the second and fourth refining plates 1026B', 1026D may range from about 0.9 mm to about 10.0 mm (±0.05 mm). This range includes all intermediate values and subranges, including, for example, 0.9, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4, 5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5 and 10.0 mm. In embodiments in which the second and/or fourth refining plates 1026B', 1026D are inclined, the gap may increase over at least a section of the refining plates 1026B', 1026D in a radial outward direction as described herein, and may increase by longitudinally over substantially the entire length L _1000' , L ₂₀₀₀ of the second and/or fourth refining plates 1026B', 1026D. In this example, the authors believe that the second (minimum) height H _2000' of the second refining plates 1026B/1036B' and the fourth (minimum) height H ₄₀₀₀ of the fourth refining plates 1026D/1036D should be at least about 0.7 mm (±0 .05 mm) less than the first height H ₁₀₀₀ ' of the first refining plates 1026A/1036A' and the third height H ₃₀₀₀ of the third refining plates 1026C, 1036C, respectively, in order to stop refining the fibers and start defibering.

In both examples, the inventors believe that the gap between the opposing portions of the refining plates must be less than about 0.9 mm (±0.05 mm) for purposes of refining (e.g., between the opposing portions of the first and third refining plates 1026A', 1036A', and 1026C, 1036C or between opposing portions of the conventional refining plates and the first and third refining plates 1026A/1036A' and 1026C/1036C). In some cases, the gap in one or more refining zones may be less than about 0.7 mm (±0.05 mm). In some specific cases, the gap may be from about 0.1 mm to about 0.5 mm (±0.05 mm). This range includes all intermediate values and subranges, including, for example, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45 and 0. 5 mm. In addition, the inventors believe that the gap should be from about 0.9 mm to about 2.0 mm (±0.05 mm) for the purpose of defibration (for example, between the opposing portions of the second and fourth refining plates 1026B', 1036B' and 1026D, 1036D or between opposing portions of conventional refining plates and second and fourth refining plates 1026B/1036B' and 1026D/1036D). This range includes all intermediate values and subranges, including, for example, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1, 7, 1.8, 1.9 and 2.0 mm. As described herein, a gap of more than about 2.0 mm can be used to compensate for the inevitable wear that reduces the heights H _1000' , H _2000' , H ₃₀₀₀ , H ₄₀₀₀ of the respective refining plates 1026A', 1036A' , 1026B', 1036B', 1026C, 1036C, 1026D, 1036D. The position of the refining bodies can be adjusted as described herein to maintain the clearance at a desired level when the refining surfaces begin to wear. In specific embodiments in which the second and/or fourth refining plates 1026B/1036B' and 1026D/1036D have a substantially continuous downward slope throughout at least a portion of the refining plate 1026B/1036B' and 1026D/1036D, we believe that when a transition between the refining and defibration zones is allowed, and a radial outward shift in the longitudinal direction occurs over a length of L _1000' , L ₂₀₀₀ of the second and/or fourth refining plates 1026B/1036B' and 1026D/1036D, such that a gap of approximately 0 .9 mm to approximately 2.0 mm for defibration, can be maintained throughout the life of the refining elements.

In fig. 13 and 14 are plan views of portions of the first refining surface 224 of the first refining body 222 and the second refining surface 234 of the second refining body 232, respectively, according to another embodiment of the present invention. As shown in FIG. 1, 13 and 14, the first and second refining bodies 222, 232 may form part of refining elements, such as refining elements 20, 30, respectively, as described herein, for use in a wood pulp refiner, such as the disk refiner 10 illustrated in fig. 1. Each of the refining elements 20, 30 containing the first and second refining bodies 222, 232, respectively, can be connected to a main support frame comprising a fixed support frame 66 attached to the first body section 12 and a movable support frame 68. One the refining element, for example, the first refining element 20 containing the first refining body 222, can be fixedly attached to the support frame 66 of the refiner 10, which defines a non-rotating stator element. Another refining element, for example, a second refining element 30 containing a second refining body 232, can be fixedly attached to a support 70, which rotates with the shaft 72 and defines a rotor that is connected to the main support frame, such that the rotation of the rotor carries out the movement of the second refining element 30 in relation to the first refining element 20.

As shown in FIG. 13, the first refining body 222 comprises a plurality of sections (not designated by individual numbers; see FIGS. 2 and 3) that may be bolted or otherwise connected to each other to form a disc-shaped refining body 222 having a radially outer edge 227. The first refining surface 224 includes a plurality of elongated first refining plates 226 separated from each other by first refining grooves 228. The first refining plates 226 extend radially outward from a radially inboard position 223 toward a radially outer edge 227 of the first refining body 222. The first refining plates 226 may be inclined at different angles, as shown in Fig. 13, and each section of the refining body 222 may include one or more segments (not designated by numbers) of refining plates 226 that are inclined in different directions. The first refining body 222 further includes one or more annular rows or rings of teeth 400 located between the first refining plates 226 and the radially outer edge 227 of the first refining body 222. Although not shown in FIG. 13, it should be understood that other sections (not designated by numbers) of the first refining body 222 will likewise contain refining plates 226, refining grooves 228 and teeth 400

As shown in FIG. 14, the second refining body 232 comprises a plurality of sections (not designated by individual numbers; see FIGS. 2 and 3) that may be bolted or otherwise connected to each other to form a disc-shaped refining body 232 having a radially outer edge 237. The second refining surface 234 includes a plurality of elongated second refining plates 236 separated from each other by second refining grooves 238. The second refining plates 236 extend radially outward from a radially inboard position 233 toward a radially outer edge 237 of the second refining body 232. The second refining plates 236 may be inclined at different angles, as shown in Fig. 14, and each section of the refining body 232 may include one or more segments (not designated by numbers) of refining plates 236 that are inclined in different directions. The second refining body 232 further includes one or more annular rows or rings of teeth 400 located between the second refining plates 236 and the radially outer edge 237 of the second refining body 232. Although not shown in FIG. 14, it should be understood that other sections (not designated by numbers) of the second refining body 232 will likewise comprise refining plates 236, refining grooves 238, and teeth 400. Additionally, although not discussed in detail herein, the design of the refining surfaces 44, 54 , respectively, of the third and fourth refining bodies 42, 52 in FIG. 1 may be a design that is substantially similar to the design of the refining surfaces 224, 234 of the first and second refining bodies 222, 232, respectively, as described herein.

In fig. 15 and 16 are detailed views of one portion of the first and second refining surfaces 224, 234 of FIG. 13 and 14, respectively. In fig. 17 is a partial sectional view of the first refining plate 226 and a tooth 400B that may be located on the first refining body 222 in FIG. 13 and 15, as well as the second refining plate 236 and teeth 400A, 400C, which may be located on the second refining body 232 in FIG. 14 and 16, with the first refining body 222 being spaced and located adjacent and opposite the second refining body 232, which defines a refining space 260 between them. As shown in FIG. 15-17, a first refining surface 224 includes first refining plates 226 that are separated from each other by first refining grooves 228, and a second refining surface 234 includes second refining plates 236 that are separated from each other by second refining grooves 238. One or both of the first and the second refining surfaces 224, 234 may include baffles 229, 239 present in at least some of the first and second refining grooves 228, 238 as described herein. Each of the first and second refining plates 226, 236 extends from a radially inward position P ₁₀₀ to a first radially outer position P ₂₀₀ on the respective first and second refining surfaces 224, 234. In some examples, the radially inward position P ₁₀₀ may be a position at or near the corresponding radially inner position 223, 233 (see FIGS. 13 and 14). The first and second refining plates 226, 236 may have a width W ₂₂₆ , W ₂₃₆ , respectively, extending between the side edges of the respective refining plates 226, 236 and ranging from about 2 mm to about 8 mm. This range includes all intermediate values and subranges, including, for example, 2.0, 2.5, 3.0, 3.5, 4 _; 0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5 and 8.0 mm.

The first refining surface 224 includes first teeth 400B located between the radially outer edge RO ₂₂₆ of the first refining plates 226 and the radially outer edge 227 of the first refining body 222. The first teeth 400B extend to a third radially outer position, for example, P ₄₀₀ , on the first refining surface 224 wherein the third radially outer position P ₄₀₀ is closer to the outermost portion, for example, the radially outer edge 227, of the first refining body 222 than the first radially outer position P ₂₀₀ of the first refining plates 226. The second refining surface 234 includes second teeth 400A, 400C, which are located between the radially outer edge RO ₂₃₆ of the second refining plates 236 and the radially outer edge 237 of the second refining body 232. The second teeth 400A, 400C extend to a second or fourth radially outer position, for example, P ₃₀₀ or P ₅₀₀ , on the second refining surface 234, wherein the second and fourth radially outer positions P ₃₀₀ , P ₅₀₀ are located closer to the outermost portion, for example, the radially outer edge 237, of the second refining body 232 than the first radially outer position P ₂₀₀ of the second refining plates 236.

In addition, as shown in FIG. 15-17, the teeth 400A-400C may be arranged in concentric rings and may extend substantially perpendicular to each other from the respective refining surfaces 224, 234. A ring containing the first teeth 400B is spaced from the radially outer edge of the first refining surfaces RO ₂₂₆ plates 226 and separated from it by a first substantially flat area 282 and separated from the radially outer edge 227 of the refining body 222 by a second substantially flat area 284. A ring containing second teeth 400A is spaced from the radially outer edge RO ₂₃₆ of the second refining plates 236 and separated from therein by a first substantially flat area 286 and is also separated from the ring including the second teeth 400C by a second substantially flat area 288. According to the embodiment illustrated in FIG. 15-17, the first refining surface 224 of the first refining body 222 includes one concentric row/ring of first teeth 400B, and the second refining surface 234 of the second refining body 232 contains two concentric rows/rings of second teeth 400A, 400C, with the first and second teeth 400A- 400C are located on respective refining surfaces 224, 234 such that the first teeth 400B engage the second teeth 400A, 400C. In other embodiments (not illustrated), the first refining surface 224 may comprise two or more concentric rings of teeth, and the second refining surface 234 may comprise one concentric row of teeth or three or more concentric rings of teeth. In all embodiments, one of the refining bodies will comprise one ring of teeth less than the other refining body, and the teeth are arranged on each refining body such that the teeth of one refining body engage the teeth of the other refining body, as is known in the art

It should be understood that the teeth 400A-400C may have any suitable shapes and/or sizes known in the art. As illustrated with respect to tooth 400A in FIG. 17, in some examples, each of the first and second teeth 400A-400C may have a substantially pyramidal or trapezoidal shape with a base 402, a radially inner face 404, a radially outer face 406, sides (not designated by separate numbers) slightly sloping inward in direction to the central axis (not designated by numbers) of the tooth 400A, and a generally flat outer surface 408. The radially inner and outer faces 404, 406 of each tooth 400A-400C may be inclined from the base 402 towards the corresponding outer surface 408. The outer surface 408 of each the teeth 400A-400C may be substantially parallel to the plane of a corresponding substantially flat region 282, 284, 288 that is located opposite the teeth 400A-400C. In other examples (not illustrated), each of the first and second teeth 400A-400C may take a shape that is substantially triangular or rectangular, or any other suitable geometric shape. As shown in FIG. 15-17, the base 402 of the teeth 400A-400C may have a radial dimension that is greater than the circumferential dimension, but in other embodiments (not illustrated), the base 402 may have a radial dimension that is less than the circumferential dimension. In some cases, at least a portion of the base 402 of the teeth 400A-400C may have a length (not designated by a number) in the longitudinal direction, i.e. in the radial direction of at least 0.6 cm, and in some specific examples the length in the longitudinal direction may be from 0.6 cm to about 2 cm. In other examples, at least a portion of the base 402 of the teeth 400A-400C may have a width (not designated by a number) in the circumferential direction, which is substantially equal to the sum of the width, for example, W ₂₂₆ , W ₂₃₆ , of one refining plate 226, 236 and the width W _G of one adjacent groove 228, 238. The width W _G can be from about 2 mm up to approximately 6 mm. This range includes all intermediate values and subranges, including, for example, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5 and 6. 0 mm. For example, the base 402 of the teeth 400A-400C may be at least about 10 mm (±0.5 mm) in the circumferential direction. In other examples, the base 402 of the teeth 400A-400C may be approximately 10 mm to 20 mm (±0.5 mm) in the circumferential direction. In addition, one or more of the radially inner and outer faces 404, 406 or sides of one or more teeth 400A-400C may include one or more radially extending projections that can cause the teeth 400A-400C to interact with wood fibers for tuft separation purposes. wood fibers. The teeth 400A-400C may have a structure similar to those illustrated in US Pat. No. 8,342,437 B2, the disclosure of which is incorporated herein by reference.

As shown in FIG. 17, the first refining plates 226 have a first height H ₁₀₀ extending upward from the bottom F ₁₀₀ of the adjacent first refining groove 228, and the second refining plates 236 have a second height H ₂₀₀ extending upward from the bottom F ₂₀₀ of the adjacent second refining groove 238. In some examples the first and second heights H ₁₀₀ , H ₂₀₀ of the first and second refining plates 226, 236 may be substantially equal to each other and may range from about 4 mm to about 10 mm (±0.5 mm). This range includes all intermediate values and subranges, including, for example, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8, 0, 8.5, 9.0, 9.5 and 10.0 mm. The first and second refining bodies 222, 232 are spaced apart and separated by a first gap G100, which is defined between the outer surface S ₂₂₆ of the first refining plate 226 and the outer surface S ₂₃₆ of the second refining plate 236. The second gap G ₂₀₀ is defined between the generally flat outer surfaces 408 of the teeth 400A-400C and the corresponding one of the substantially flat areas 282, 284, 288, which is opposite the tooth 400A-400C, and G ₂₀₀ may be more than G ₁₀₀ . In some examples, the height (not designated by number) of teeth 400A-400C extending upward from an adjacent corresponding first or second refining groove 228, 238 may be approximately 8 to 10 mm. This range includes all intermediate values and sub-ranges, including, for example, 8.0, 8.5, 9.0, 9.5 and 10.0 mm. As shown in FIG. 17, teeth 400A-400C engage such that a portion of one or both of the radially inner or outer faces 404, 406 of each tooth 400A-400C overlap in the axial direction, for example, in the direction of arrow A in FIG. 1, with a portion of the radially inner or outer face surface 404, 406 of the adjacent tooth 400A-400C. The overlapping portions of the teeth 400A-400C may be spaced apart and separated by a third gap G ₃₀₀ that is defined between the respective radially inner or outer faces 404, 406 of the teeth 400A-400C. In some examples, G ₃₀₀ can be almost equal to G ₂₀₀ . In other examples, G ₃₀₀ may be less than or greater than G ₂₀₀ .

As shown in FIG. 1 and 17, as the wood fiber slurry enters the refiner frame 10, such as inlet 16, the wood fibers pass into a portion of the refining space 260 that is at least partially defined by the first and second refining grooves 228, 238, such as from approximately the first radially internal position P ₁₀₀ to approximately the first radially external position P ₂₀₀ . The first and second refining plates 226, 236 cooperate with each other to refine a significant number of wood fibers in the wood pulp, as described herein. We believe that the first gap G ₁₀₀ should be less than about 0.9 mm (±0.05 mm) and preferably from about 0.2 mm to about 0.9 mm (±0.05 mm) for refining to occur. This range includes all intermediate values and subranges, including, for example, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0, 6, 0.65, 0.7, 0.75, 0.8, 0.85 and 0.9 mm. The refined wood fibers then pass into a portion of the refining space 260 that is at least partially defined by respective first and second substantially flat regions 282, 284, 286, 288, for example, from about the first radially outer position P ₂₀₀ to about the fourth radially outer position P ₅₀₀ . The authors believe that the second and third gaps of G ₂₀₀ and G ₃₀₀ should be between about 0.9 mm and about 1.5 mm (±0.05 mm) for defibration to occur. This range includes all intermediate values and subranges, including, for example, 0.9, 0.95, 1.0, 1.05, 1.1, 1.15, 1.2, 1.25, 1. 3, 1.35, 1.4, 1.45 and 1.5 mm. The teeth 400A-400C are configured to grind or separate multiple bundles of wood fibers in a wood pulp slurry, as described herein. The gap G ₂₀₀ is greater than G ₁₀₀ and thus the inventors believe that refining stops and defibration begins approximately at the first radially outer first position P ₂₀₀ .

As shown in FIG. 1 and 15-17, the refining surfaces 224, 234 of the refining bodies 222, 232, in particular, the outer surfaces S ₂₂₆ , S ₂₃₆ of the first and second refining plates 226, 236 and the outer surfaces 408 of the teeth 400A-400C, can be subject to wear and destruction with over time. To compensate for this wear, the space between the first and second refining elements 20, 30 containing the first and second refining bodies 222, 232, respectively, can be readjusted as described herein such that the first gap G ₁₀₀ remains substantially constant. This adjustment of the first and second refining bodies 222, 232 may cause the second gap G ₂₀₀ to decrease as the refining plates 226, 236 perform the refining function more intensively and generally experience wear faster than the teeth 400A-400C. This difference in wear may play a role in the selection of teeth 400A-400C (e.g., the type(s) of metal used for teeth 400A-400C, the initial size of the second gap G ₂₀₀ , the shape of teeth 400A-400C, etc.), thus that a sufficient second gap G ₂₀₀ can be maintained to ensure that refining stops and defibration begins as wood fibers enter a portion of refining space 260 that is at least partially defined by respective first and second substantially flat regions 282, 284, 286, 288. When the refining bodies 222, 232 are new, the third gap G ₃₀₀ may be substantially equal to or greater than the second gap G ₂₀₀ . As the refining surfaces 224, 234 wear and the refining elements 20, 30 move and approach each other, the third gap G ₃₀₀ may decrease until the third gap G ₃₀₀ is less than the second gap G ₂₀₀ .

In all embodiments described herein, the refiner 10 in FIG. 1, a controller (not illustrated) may be attached to receive data provided by a fiber analyzer (e.g., a Valmet® MAP wood pulp analyzer from Valmet Corp.) regarding one or more fiber properties measured at one or more points downstream relative to refiner 10, such as number, size and other parameters of fiber bundles (also referred to as "wide partial fiber bundles"), fibrillation, Canadian pulp density, fiber length, fiber width, twist, crimp, roughness, number of fine fibers and etc. Based on this data, the controller may adjust the operation of the refiner 10 as part of a feedback circuit. For example, the controller may adjust the distance between one or more pairs of refining elements 20, 30, 40, 50 to maintain one or more fiber properties within a predetermined target range. In some examples, the inventors believe that, based on this data, the controller may also increase or decrease the rotation speed of one or more rotating rotor elements of the refiner 10 (eg, the second and third refining elements 30, 40). In other examples, the controller may regulate the operation of the refiner 10, including changing the size of the refining gap G ₁ , G ₁₀₀ and the defibration gap G ₂ , G ₃ , G ₄ , G ₅ , G ₆ , G ₂₀₀ , G ₃₀₀ to produce refined softwood wood pulp that has less than a predetermined number, for example 1000 ppm, of fiber bundles having a specified size, for example a width of from about 150 to 2000 microns and a length of from 0.3 to 40 mm .

In other examples, the refining elements 20, 30, 40, 50 of the present invention may be installed in one or more of a plurality of refiners that are arranged in series, each refiner being substantially similar to refiner 10 in FIG. 1. The controller may regulate the operation of one or more of a plurality of refiners to maintain one or more fiber properties within a predetermined target range. In some specific examples, the refining elements 20, 30, 40, 50 of the present invention may be installed in only the final refiner of a given sequence, and in other examples, the refining elements 20, 30, 40, 50 of the present invention may be installed in two or more number of refiners.

In fig. 18 is a flow chart illustrating an exemplary method for processing wood fibers. Although reference is made to the components of refiner 10 in FIG. 1, it should be understood that the method is not limited to this design. The method may begin at step 500 of providing a refiner 10 comprising at least a first pair of refining elements 20 and 30, 40 and 50. The at least one pair of refining elements may include a first refining element 20 comprising a first refining body 22 having a first refining surface 24, and a second refining element 30 including a second refining body 32 having a second refining surface 34. The first refining surface 24 may include first refining plates 26A separated by first refining grooves 28A and second refining plates 26B separated by second refining grooves 28B, wherein the first refining plates 26A have a first maximum height H ₁ extending upward from the bottom F ₁ of the adjacent first refining groove 28A, and the second refining plates 26B have a second maximum height H ₂ extending upward from the bottom F ₂ of the adjacent second refining groove 28B. The second refining surface 34 may include refining plates of a second element 36 separated by refining grooves of a second element 38. The first refining element 20 may be spaced from the second refining element 30, defining a refining space 60 between them. At least some of the refining plates of the second element 36 may be positioned to be opposite the second refining plates 26B of the first refining element 20 such that a gap G ₂ , G ₃ , G ₄ , G ₅ , G ₆ between the part is defined refining plates of the second element 36 and second refining plates 26B.

The method may continue by rotating at least one of the first refining element 20 and the second refining element 30 such that the first and second refining elements 20, 30 move relative to each other at step 510, and introducing a slurry of wood pulp including wood fibers into refiner 10 such that the slurry passes through refining space 60 at step 520. At step 530, axial pressure may be applied to at least one of the first refining element 20 and the second refining element 30 as the slurry enters , such that the gap G ₂ , G ₃ , G ₄ , G ₅ , G ₆ between the part of the refining plates of the second element 36 and the second refining plates 26B is from about 0.9 mm to about 1.5 mm, and are separated by at least some of the wood fiber bundles passing through the gap G ₂ , G ₃ , G ₄ , G ₅ , G ₆ , and then the method can be completed.

In fig. 20 is a flow chart illustrating another exemplary process for processing wood fibers. Although reference is made to the components of refiner 10 in FIG. 1, it should be understood that the method is not limited to this design. For example, the refiner may be a conical refiner. The method may begin at step 600 of providing a refiner 10 comprising at least a first pair of refining elements 20 and 30, 40 and 50. The at least one pair of refining elements may include a first refining element 20 comprising a first refining body having a first refining surface. The first refining surface may include first refining plates, such as refining plates 26A, 26A', 1026A, 1026A' in FIG. 6A, 6B, 19A, and 19B that separate the first refining grooves and the second refining plates, such as refining plates 26B, 26B', 1026B, 1026B' in FIG. 6A, 6B, 19A, and 19B that separate second refining grooves, the first refining plates having a first height extending upward from the bottom of the adjacent first refining groove, and the second refining plates having a second height extending upward from the bottom of the adjacent second refining groove. The at least one pair of refining elements may further comprise a second refining element 30 comprising a second refining body having a second refining surface. The second refining surface contains a second refining element containing refining plates, for example, refining plates 36, 36', 1036, 1036' in FIG. 6A, 6B, 19A and 19B, which separate the refining grooves of the second refining element. The first refining element 20 may be spaced from the second refining element 30, defining a refining space 60 between them. At least some of the refining plates of the second refining element may be positioned such that they are opposite the second refining plates of the first refining element, defining a gap between some of the refining plates of the second refining element and the second refining plates.

The method may continue by rotating at least one of the first refining element 20 and the second refining element 30 such that the first and second refining elements 20, 30 move relative to each other at step 610, and introducing a slurry of wood pulp containing wood fibers into the refiner 10 such that the slurry passes through the refining space 60 at step 620. At step 630, axial pressure may be applied to at least one element of the first refining element 20 and the second refining element 30 while introducing the slurry, wherein at least some of the wood fiber bundles passing through the gap are separated, and the method can then be completed. The gap defined between some of the refining plates of the second refining element and the second refining plates may increase over at least a section of the second refining plates in a direction extending from a first radially inward position to a first radially outer position on the first refining surface.

While specific embodiments of the present invention have been illustrated and described, it should be understood that various changes and modifications may be made without departing from the spirit or scope of the present invention. Thus, the appended claims are intended to cover all such changes and modifications that fall within the scope of the present invention.

Claims (39)

1. A refining element for a pulp refiner, the refining element comprising: refining body having a refining surface containing: first refining plates separated by first refining grooves and extending from a first radially inward position to a first radially outer position on the refining surface; And second refining plates separated by second refining grooves and extending from a second radially inner position to a second radially outer position on the refining surface, the second radially outer position being closer to the outermost portion of the refining body than the first radially outer position, wherein: the first refining plates have a first height extending upward from the bottom of the adjacent first refining groove; the second refining plates have a second height extending upward from the bottom of the adjacent second refining groove, the second height being the minimum height of the second refining plates and spaced from the second radially inward position, the second height being at least 0.35 mm less , than the first height; And the first refining plates are configured to refine wood fibers, and the second refining plates are configured to refine fiber bundles. 2. The refining element according to claim 1, wherein the minimum height of the second refining plates is near the second radially outer position. 3. Refining element according to claim 1, in which the first height is from 4.0 mm to 10.0 mm. 4. The refining element according to claim 3, in which the second height is less than the first height, and their difference is from 0.35 mm to 7.0 mm. 5. The refining element according to claim 3, in which the second height is less than the first height, and their difference is from 0.7 mm to 7.0 mm less than the first height. 6. The refining element according to claim 1, wherein the second refining plates are integral with the first refining plates such that the second refining plates extend from the first radially outer position to the second radially outer position. 7. The refining element of claim 6, wherein each of the second refining plates is inclined downward continuously over at least a portion of each of the second refining plates extending between the first radially outer position and the second radially outer position. 8. The refining element according to claim 1, wherein at least some of the first refining grooves are provided with baffles. 9. The refining element of claim 1, wherein the first height of the first refining plates is a first maximum height, and the second refining plates have a second maximum height extending upward from the bottom of an adjacent second refining groove, wherein a radially outer portion of each of the first refining plates includes a stepped a decrease from the first maximum height to the second maximum height, wherein the second maximum height is at least 1.5 mm less than the first maximum height. 10. Refining element according to claim 1, additionally containing: third refining plates separated by third refining grooves, each of the third refining plates extending to a third radially outer position on the refining surface; And fourth refining plates separated by fourth refining grooves, each of the fourth refining plates extending to a fourth radially outer position on the refining surface that is closer to the outermost portion of the refining body than the third radially outer position, wherein the third refining plates have a third height extending upward from the bottom of the adjacent third refining groove, and the fourth refining plates have a fourth height extending upward from the bottom of the adjacent fourth refining groove, wherein the fourth height represents the minimum height of the fourth refining plates and is adjacent to the fourth a radially outer position, wherein the fourth height is at least 0.35 mm less than the third height; And wherein the third refining plates are configured to refining wood fibers, and the fourth refining plates are configured to grind fiber bundles. 11. The refining element of claim 10, wherein the third refining plates are integral with the second refining plates such that the third refining plates extend from the second radially outer position to the third radially outer position, and the fourth refining plates are integral with the third refining plates such that the fourth refining plates extend from the third radially outer position to the fourth radially outer position. 12. The refining element of claim 10, wherein the third height of the third refining plates is a third maximum height, and the fourth refining plates have a fourth maximum height extending upward from the bottom of the adjacent fourth refining groove, the radially outer portion of each of the third refining plates comprising a step reduction from a third maximum height to a fourth maximum height, wherein the fourth maximum height is at least 1.5 mm less than the third maximum height. 13. A pulp refiner containing: frame; at least the first pair of refining elements, which consists of: a first refining element connected to the frame and containing a first refining body having a first refining surface and containing: first refining plates separated by first refining grooves and extending from a first radially inward position on the refining surface to a first radially outer position on the refining surface; And second refining plates separated by second refining grooves and extending from a second radially inner position on the refining surface to a second radially outer position on the refining surface, the second radially outer position being closer to the outermost portion of the refining body than the first radially outer position, wherein the first refining plates have a first height extending upward from the bottom of the adjacent first refining groove, and the second refining plates have a second height extending upward from the bottom of the adjacent second refining groove, wherein the second height represents the minimum height of the second refining plates and is spaced from a second radially inner position, the second height being at least 0.35 mm less than the first height; a second refining element connected to the frame and containing a second refining body having a second refining surface and containing refining plates of the second refining element, separated by refining grooves of the second refining element, and the first refining element is spaced from the second refining element, defining a refining space between them, wherein at least some of the refining plates of the second refining element are arranged such that they are opposite the second refining plates of the first refining element, forming a gap between some of the refining plates of the second refining element and the second refining plates; And a rotor connected to the frame and connected to one of the first refining element and the second refining element, such that when the rotor rotates, one element of the first and second refining elements moves relative to the other element, wherein, when the wood fiber slurry containing wood fibers enters the frame, the wood fiber slurry passes through the refining space so that a significant number of wood fibers in the wood fiber slurry are refined, and a plurality of wood fiber bundles in the wood fiber slurry are separated . 14. The pulp refiner of claim 13, wherein the minimum height of the second refining plates is near the second radially outer position. 15. The pulp refiner according to claim 13, wherein the second height is at least 0.7 mm less than the first height. 16. The pulp refiner of claim 13, wherein the first height of the first refining plates is a first maximum height and the second refining plates have a second maximum height extending upward from the bottom of an adjacent second refining groove, wherein a radially outer portion of each of the first refining plates comprises a stepped a decrease from the first maximum height to the second maximum height, wherein the second maximum height is at least 1.5 mm less than the first maximum height. 17. The pulp refiner according to claim 13, wherein the refining plates of the second refining element contain: first refining plate elements extending from a first radially inward position to a first radially outer position on the second refining surface; And second refining plate elements extending to a second radially outer position on the second refining surface that is located closer to the outermost portion of the second refining body than the first radially outer position, wherein the first refining plate elements have a first refining plate height extending upward from the bottom of the adjacent groove, and the second refining plate elements have a second refining plate height extending upward from the bottom of the adjacent groove, wherein the second refining plate height is the minimum height of the second refining plate elements and is located near the second radially outer position, and the height of the second refining plates is at least 0.35 mm less than the height of the first refining plates.