RU2771695C2 - Method for processing wood fibres, refining elements and wood pulp refiners - Google Patents

Abstract

FIELD: wood processing.

SUBSTANCE: group of inventions relates to refining elements for a wood pulp refiner, wood pulp refiners, and a method for processing wood fibres, wherein the refining element includes a refining body with a refining surface including first and second refining plates separated by first and second refining grooves, respectively. The first refining plates extend from the radially internal position to a first radially external position. The second refining plates extend to a second radially external position closer to the farthermost from the centre part of the refining body than the first radially external position. The second refining plates have a length in the longitudinal direction ranging from approximately 0.6 cm to approximately 10 cm. The first and second refining plates have the corresponding first and second maximum height extending upwards from the bottom of the corresponding adjacent first or second refining groove. The second maximum height is at least 0.35 mm less than the first maximum height. The first refining plates are configured to refine wood fibres, and the second refining plates are configured to grinde fibre bundles.

EFFECT: technical result is an improved technology of wood refining.

29 cl, 22 dwg

Description

Related Applications

This application is related to the following application, which is filed simultaneously with it, and which is incorporated herein by reference in its entirety: US Patent Application No. 15/860,006 (Patent Attorney Case No. TEC-120257-US), entitled FOR PROCESSING WOOD FIBER” (Dwight Anderson).

TECHNICAL FIELD OF THE 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 grinding fiber bundles.

State of the art of the present invention

Disc type refiners have traditionally been used to process wood fibers at the stage of the paper product manufacturing process. Such refiners include 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 with respect to the other, and during rotation, the cutting surfaces of the refining plates cut the wood fibers being 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, for example in a separate cone mill type refiner or deflocculator.

Brief summary of the present invention

According to a first aspect of the present invention, a refining element for a wood pulp refiner is provided. The refining element includes a refining body including a refining surface including first refining plates separated by first refining grooves and second refining plates separated by second refining grooves. Each of the first refining plates extends from a radially inward position on the refining surface to a first radially outward position on the refining surface. Each of the second refining plates extends to a second radially outward position on the refining surface. The second refining plates have a longitudinal length of from about 0.6 cm to about 10 cm, with the second radially outward position being closer to the most distal portion of the refining body than the first radially outward position. The first refining plates have a first maximum height extending upward from the bottom of the adjacent first refining groove, and the second refining plates have a second maximum height extending upward from the bottom of the adjacent second refining groove. The second maximum height is at least 0.35 mm less than the first maximum height. The first refining plates are configured to refine wood fibers, and the second refining plates are configured to refine fiber bundles.

The first maximum height of the first refining plates, as measured from the bottom of the adjacent first refining groove, may be from about 4 mm to about 10 mm. The second maximum height of the second refining plates, as measured from the bottom of the adjacent second refining groove, may be less than the first maximum height and may be between about 0.35 mm and about 1.5 mm apart. The second maximum height of the second refining plates, which is measured from the bottom of the adjacent second refining groove, may be less than the first maximum height and may differ from about 0.7 mm to about 1.5 mm.

The longitudinal length of the second refining plates may be from about 2 cm to about 10 cm.

The second refining plates may be integral with the first refining plates such that the second refining plates extend from the first radially outward position to the second radially outward position. Each of the second refining plates may have a continuous downward slope from the first radially outward position to the second radially outward position.

The first and second refining plates may have a width between side edges of about 2 mm to about 8 mm.

At least some of the first refining grooves may be provided with baffles. The refining element may further include 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 outward position on the refining surface, and each of the fourth refining plates may extend to a fourth radially outward position on the refining surface. The fourth refining plates may have a longitudinal length of from about 0.6 cm to about 10 cm. The fourth radially outward position may be closer to the most distal portion of the refining body than the third radially outward position. The third refining plates may have a third maximum height extending upward from the bottom of an adjacent third refining groove, and the fourth refining plates may have a fourth maximum height extending upward from the bottom of an adjacent fourth refining groove. The fourth maximum height may be at least 0.35 mm less than the third maximum 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 the second radially outward position to the third radially outward position, and the fourth refining plates may be integral with the third refining plates such that the fourth refining plates the plates extend from the third radially outward position to the fourth radially outward position.

According to a second aspect of the present invention, a wood pulp refiner is provided. The wood pulp refiner includes: a frame, at least a first pair of refining elements, and a rotor connected to the frame. The refining elements include the first refining element connected to the frame and including the first refining body, and the second refining element connected to the frame and including the second refining body. The first refining body includes the first refining surface, including: the first refining plates separated by the first refining grooves, each of the first refining plates extending from the radially inner position on the refining surface to the first radially outer position on the refining surface, and the second refining plates separated by the second refining grooves. grooves, each of the second refining plates extending to a second radially outward position on the refining surface. The second refining plates have a longitudinal length of from about 0.6 cm to about 10 cm. The second radially outward position may be closer to the most distal portion of the refining body than the first radially outward position. The first refining plates have a first maximum height extending upward from the bottom of the adjacent first groove, and the second refining plates have a second maximum height extending upward from the bottom of the adjacent second groove. The second maximum height is at least 0.35 mm less than the first maximum height. The second refining element includes a second refining surface, including refining plates of the second element, separated by refining grooves of the second element. The first refining element is located at a distance from the second refining element, which defines the refining space between them. The rotor is connected to one of the first refining element and the second refining element, so that the rotation of the rotor moves one of the first and second refining elements with respect to the other. When the wood pulp slurry including wood fibers enters the frame, the wood pulp slurry passes through the refining space such that a significant amount of wood fibers in the wood pulp slurry is refined and a plurality of wood fiber bundles in the wood pulp slurry are separated.

The second maximum height may be at least 0.7 mm less than the first maximum height.

The longitudinal length of the second refining plates may be from about 2 cm to about 10 cm.

The refining plates of the second element may include: third refining plates extending from a radially inward position on the second refining surface to a first radially outward position on the second refining surface, and fourth refining plates extending to a second radially outward position on the second refining surface. The second radially outward position may be closer to the outermost portion of the second refining body than the first radially outward position. The third refining plates may have a third maximum height extending upward from the bottom of the adjacent groove, and the fourth refining plates may have a fourth maximum height extending upward from the bottom of the adjacent groove. The fourth maximum height may be at least 0.35 mm less than the third maximum height.

The first refining element may be a non-rotating stator element and the second refining element may be a rotating rotor element.

According to a third aspect of the present invention, a method for treating wood fibers is provided. The method includes: providing a refiner including at least a first pair of refining elements. The refining elements include: the first refining element, including the first refining body, and the second refining element, including the second refining body. The first refining body includes the first refining surface, including: the first refining plates separated by the first refining grooves and having the first maximum height extending upward from the bottom of the adjacent first refining groove, and the second refining plates separated by the second refining grooves and having the second maximum height extending up from the bottom of the adjacent second refining groove. The second refining body includes a second refining surface, including refining plates of the second element, separated by refining grooves of the second element. The first refining element is located at a distance from the second refining element, which defines the refining space between them. At least part of the refining plates of the second element is opposite the second refining plates, so that a gap between a part of the refining plates of the second element and the second refining plates is determined.

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 wood pulp slurry comprising 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 as the slurry enters such that a gap between a portion of the refining plates of the second element and the second refining plates is from about 0.9 mm to about 1.5 mm, wherein at least some of the wood fiber bundles passing through the gap are separated.

The second refining plates may have a longitudinal length of from about 0.6 cm to about 10 cm and the second maximum height may be at least 0.35 mm less than the first maximum height. The longitudinal length of the second refining plates may be from about 2 cm to about 10 cm.

The refining plates of the second element may include: third refining plates and fourth refining plates. The third refining plates may have a third maximum height extending upward from the bottom of the adjacent groove, and the fourth refining plates may have a fourth maximum height extending upward from the bottom of the adjacent groove. The fourth maximum height may be at least 0.35 mm less than the third maximum height.

According to a fourth aspect of the present invention, a refining element for a wood pulp refiner is provided.

The refining element includes: a refining body, including a plurality of radially passing sector segments, including: at least one first sector segment and at least one second sector segment. At least one first sector segment includes a first refining surface, including first refining plates separated by first refining grooves.

The first refining plates have a first maximum height extending upward from the bottom of the adjacent first refining groove. At least one second sector segment includes a second refining surface, including second refining plates separated by second refining grooves. The second refining plates have a second maximum height extending upward from the bottom of the adjacent second refining groove. The second maximum height is at least 0.35 mm less than the first maximum height. The first refining plates are configured to refine wood fibers, and the second refining plates are configured to refine fiber bundles.

The first maximum height of the first refining plates, as measured from the bottom of the adjacent first refining groove, may be from about 4 mm to about 10 mm.

The second maximum height of the second refining plates, which is measured from the bottom of the adjacent second refining groove, may be less than the first maximum height and may differ from about 0.35 mm to about 1.5 mm.

The second maximum height of the second refining plates, which is measured from the bottom of the adjacent second refining groove, may be less than the first maximum height, and their difference may be from about 0.7 mm to about 1.5 mm.

According to a fifth aspect of the present invention, a wood pulp refiner is provided.

The wood pulp refiner includes: a frame, at least a first pair of refining elements, and a rotor connected to the frame. The refining elements include: the first refining element associated with the frame and including the first refining body, and the second refining element associated with the frame and including the second refining body. The first refining body includes a plurality of radially extending sector segments, including: at least one first sector segment and at least one second sector segment. At least one first sector segment includes a first refining surface, including first refining plates separated by first refining grooves. The first refining plates have a first maximum height extending upward from the bottom of the adjacent first refining groove. At least one second sector segment includes a second refining surface, including second refining plates separated by second refining grooves. The second refining plates have a second maximum height extending upward from the bottom of the adjacent second refining groove. The second maximum height is at least 0.35 mm less than the first maximum height. The second refining body includes a refining surface of the second element, including refining plates of the second element, separated by refining grooves of the second element. The first refining element is located at a distance from the second refining element, which defines the refining space between them.

The rotor is connected to one of the first refining element and the second refining element, so that the rotation of the rotor moves the first and second refining elements relative to each other. When the wood pulp slurry including wood fibers enters the frame, the wood pulp slurry passes through the refining space such that a significant amount of wood fibers in the wood pulp slurry is refined and a plurality of wood fiber bundles in the wood pulp slurry are separated.

The second maximum height of the second refining plates, which is measured from the bottom of the adjacent second refining groove, may be less than the first maximum height and may differ from about 0.35 mm to about 1.5 mm.

The second maximum height of the second refining plates, which is measured from the bottom of the adjacent second refining groove, may be less than the first maximum height, and their difference may be from about 0.7 mm to about 1.5 mm.

The second refining body may include a plurality of radially extending sector segments, including: at least one third sector segment and at least one fourth sector segment. At least one third sector segment may include a third refining surface, including third refining plates separated by third refining grooves. The third refining plates may have a third maximum height extending upward from the bottom of an adjacent third refining groove. At least one fourth sector segment may include a fourth refining surface, including fourth refining plates separated by fourth refining grooves. The fourth refining plates may have a fourth maximum height extending upward from the bottom of an adjacent fourth refining groove.

The fourth maximum height may be at least 0.35 mm less than the third maximum height. The third and fourth refining plates may define the refining plates of the second element, and the third and fourth refining grooves may define the refining grooves of the second element.

The first refining element may be a non-rotating stator element and the second refining element may be a rotating rotor element.

According to a sixth aspect of the present invention, a refining element for a wood pulp refiner is provided. The refining element includes a refining body including a refining surface including: refining plates separated by refining grooves, each of the refining plates extending from a radially inward position on the refining surface to a first radially outward position on the refining surface; and teeth extending to a second radially outward position on the refining surface. The second radially outward position is closer to the outermost portion of the refining body than the first radially outward position. The refining plates are made with the possibility of refining wood fibers, and the teeth are made with the possibility of grinding fiber bundles.

The refining plates may have a first maximum height, measured from the bottom of an adjacent refining groove, from about 4 mm to about 10 mm.

The refining plates may have a width between side edges ranging from about 2 mm to about 8 mm.

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

According to a seventh aspect of the present invention, a wood pulp refiner is provided.

The wood pulp refiner includes a frame, at least a first pair of refining elements, and a rotor connected to the frame. The refining elements include the first refining element associated with the frame and including the first refining body, including the first refining surface and the second refining element associated with the frame and including the second refining body, including the second refining surface. The first refining surface includes: first refining plates separated by first refining grooves, each of the first refining plates extending from a radially inward position on the first refining surface to a first radially outward position on the first refining surface, and first teeth extending to the next radially outward position on first refining surface. The next radially outward position is closer to the outermost portion of the first refining body than the first radially outward position. The first refining element is located at a distance from the second refining element, which defines the refining space between them. The rotor is connected to one of the first refining element and the second refining element, so that the rotation of the rotor moves the first and second refining elements relative to each other. When the wood pulp slurry including wood fibers enters the frame, the wood pulp slurry passes through the refining space such that a significant amount of wood fibers in the wood pulp slurry is refined and a plurality of wood fiber bundles in the wood pulp slurry are separated.

The second refining element may include a second refining body, including a second refining surface, including: second refining plates separated by second refining grooves, each of the second refining plates extending from a radially inward position on the second refining surface to a first radially outward position on the second refining surface, and second teeth extending to a second radially outward position on the second refining surface. The second radially outward position may be closer to the outermost portion of the second refining body than the first radially outward position.

The second refining surface may include a first row of second teeth extending to a second radially outward position on the second refining surface and a second row of second teeth extending to a fourth radially outward position on the second refining surface. The first teeth mesh with the second teeth.

The first refining element may be a non-rotating stator element and the second refining element may be a rotating rotor element.

Brief description of the figures

While the description of the invention is consistent with the claims, by disclosing and expressly stating the present invention, the authors believe that the present invention will become more clear from the following description in combination with the accompanying graphic figures, in which like reference numbers designate like elements, and at the same time:

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

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

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

in fig. 5A and 5B are plan views of the refining surface section of the second refining body 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. 4V and 5V;

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 which is spaced and positioned above the corresponding refining plate on a second refining body;

in fig. 10 and 11 are plan views of parts of the first and second refining bodies, respectively, including a plurality of radially extending sector segments;

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

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

in fig. 15 is a plan view of the refining surface section of the first refining body in FIG. thirteen;

in fig. 16 is a plan view of the refining surface section of the second refining body in FIG. fourteen;

in fig. 17 is a partial sectional view of a refining plate and prong on a first refining body which is spaced and positioned above a second refining body including the refining plate and prongs; and

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

Detailed disclosure of the present invention

In the following detailed description of the preferred embodiments, reference is made to the accompanying figures, which form part of it, and which provide, by way of illustration and not as limitation, specific preferred embodiments in which the present invention may be practiced. It should be understood that other embodiments can be used and that changes can be made without departing from the idea and going beyond the scope of the present invention.

In FIG. 1 is a schematic partial sectional view of a disk refiner according to the present invention. The disc refiner 10 includes a casing with a first casing section 12 and a second casing section 14, which can be bolted or otherwise connected in a fixed manner to each other. The body sections 12, 14 define an inlet 16, an outlet 18, and an interior 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 the first refining surface 24, and the second refining element 30 includes a second refining body 32 with a second refining surface 34. The third refining element 40 includes a third refining body 42 and a third refining surface 44, and the fourth refining element 50 includes a fourth refining body 52 and a fourth refining surface 54. Each of the refining elements 20, 30, 40, 50 is 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, as described herein.

The first, second, third and fourth refining bodies 22, 32, 42, 52 may typically be disc-shaped with substantially the same outside diameter (see FIGS. 2 and 3). The first and second refining elements 20, 30 are positioned such that the first refining surface 24 faces the second refining surface 34, and the third and fourth refining elements 40, 50 are positioned 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 the 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 the second refining space 62 between the respective refining surfaces 44 , 54. Disc refiner 10 may have a structure 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 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 means of bolts or other suitable fasteners (not illustrated). The second and third refining elements 30, 40 can be attached to a support 70 which is attached to and extends radially outward from the rotating shaft 72. The support 70 is attached to the shaft 72 in such a way that it rotates with the shaft 72 and is also capable of axial movement along the shaft. 72. Shaft 72 is driven by first motor 74 such that support 70 and second and third refining elements 30, 40 rotate with shaft 72 during operation of disc refiner 10. Shaft 72 has a central axis 72A which is typically coaxial with the axis of rotation. second and third refining elements 30, 40. Shaft 72 may be rotatably mounted on a fixed support frame 66 such that the first and second refining elements 30, 40 are associated with 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 means of bolts or other suitable fasteners (not illustrated). Therefore, support 70 and shaft 72 may define a rotor associated with 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. Rotation of the rotor moves the second and third refining elements 30, 40 relative to the first and fourth refining elements 20, 50, respectively.

The fixed support frame 68 may be mounted in the second body section 14 and connected to a second motor 76, which may be a reversible electric motor in a fixed position. Second motor 76 moves movable support frame 68 in a substantially horizontal (i.e., axial) direction, represented by arrow A. Refiner 10 may include, for example, a screw jack (not illustrated) attached to second motor 76 and 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. 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). According to other embodiments (not illustrated), the regulation of the size of the gaps can be achieved by means of one or more magnetic bearings. Magnetic bearings that control the axial position of shaft 72 may be used to control the position of rotating rotor members that are fixedly attached to shaft 72. Magnetic bearings may be used to control the axial position of one or more additional movable sections of the main support frame, i. a movable support frame 68 to which one or more non-rotating stator elements are attached.

As will be discussed later herein, a pulp slurry including wood fibers passes through the refining spaces 60, 62. 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, support 70, and the second refining element 30 move inward towards the first refining element 20. When the screw jack 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. refining element 40. This reduces the axial force applied by the fourth refining element 50 to the wood pulp slurry passing through the second refining space 62, which in turn reduces the axial force applied by the wood pulp slurry to the third refining element 40. Here, the axial force applied by the pulp slurry 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 applied by the pulp suspension passing through the first and second refining spaces 60, 62 to the second and third refining elements 30 and 40.

In some embodiments (not illustrated), the disc refiner 10 may further include a further motor and a second rotating shaft, and the 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 can rotate in the opposite direction with respect to the second and/or third refining elements 30, 40, respectively. In other embodiments (not illustrated), the disc refiner 10 may include 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 include three or more pairs of refining elements. In the following embodiments (not illustrated), the 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 wood pulp refiner according to one embodiment of the present invention. Although it is not discussed in detail herein, the structure 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 structure of the refining surfaces 24, 34, respectively, of the first and second refining tel 22, 32.

As shown in FIG. 1 and 2, the first refining body 22 may include a plurality of sections, such as sections 22A-22C, which are connected to each other by bolts or otherwise to form a disc-shaped refining body 22, including a radially outer edge 27. The refining surface 24 includes a plurality of oblong refining plates 26 separated from each other by refining grooves 28. Although not shown in FIG. 2, it should be understood that other sections (not numbered) of the first refining body 22 will likewise include refining plates 26 and refining grooves 28. The refining plates 26 extend radially outward from the radially inward position 23 toward the radially outer edge 27 of the first refining body. 22. The refining plates 26 can be tilted at different angles, as illustrated in FIG. 2, and each section 22A-22C may include one or more segments (not individually numbered) 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 structurally similar in other respects.

As shown in FIG. 3, the second refining body 32 may likewise include a plurality of sections, such as sections 32A-32C, which are bolted or otherwise connected to each other to form a disc-shaped refining body 32 including a radially outer edge 37. The refining surface 34 includes a plurality of elongated refining surfaces. plates 36 separated from each other by refining grooves 38. Although not shown in FIG. 3, it should be understood that other sections (not numbered) of second refining body 32 will likewise include refining plates 36 and refining grooves 38. Refining plates 36 extend radially outward from the radially inward position 33 towards the radially outer edge 37 of the second refining body. body 32. The refining plates 36 can be tilted at different angles, as shown in FIG. 3, and each section 32A-32C may include two or more segments (not individually numbered) 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 structurally similar.

The paths of the wood pulp slurry, including wood fibers, through the refiner 10 are illustrated by arrows B in FIG. 1. As shown in FIG. 1-3, the wood pulp slurry enters the disc refiner 10 through inlet 16 and passes into the refiner inner cavity 64 through a central opening 21 in the first refining element 20. The refiner inner cavity 64 may be defined by a partially fixed support frame 66 and a movable support frame 68. The refining surfaces 24, 34 may include one or more additional rows of refining plates (not indicated 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 can be wider and located with at longer intervals than the other refining plates 26 to break up 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, defined between the first and second refiner refining elements 20, 30 and a second refining space 62 defined between the third and fourth refining elements 40, 50 define the separate paths that wood fibers can take from inlet 16 to outlet 18. The authors believe that wood fibers only pass 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 passes through the refining grooves 28, 38. Similarly, 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 bulkthe flow of wood fibers through the refining space 62 passes through the refining grooves (not numbered) of the third and fourth refining elements 40, 50. After processing, the wood fibers exit the refiner 10 through the 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 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 FIGS. 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 FIG. 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 first refining grooves 28A, 38A, and the second refining plates 26B, 36B may be separated from each other by 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. As shown in FIG. 6A and 7, the first refining plates 26A, 36A include 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 include a second maximum height H ₂ extending upward from the bottom F ₂ adjacent second refining groove 28B, 38B, wherein the second maximum height H ₂ is less than the first maximum height H ₁ . the minimum height difference between H ₁ and H ₂ is denoted as D ₁ in FIG. 6A. In some examples, the radially outer portion RO _{1 of} the first refining plate 26A, 36A may include a stepped reduction from the first maximum height Hi to the second maximum height H ₂ .

In some examples, the second maximum height H ₂ may be at least 0.35 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 less than the first maximum height H ₁ . In the following examples, the first maximum height Hi of the first refining plates 26A, 36A, as measured from the bottom F _{1 of} the adjacent first refining groove 28A, 38A, may be from about 4 mm to about 10 mm. In a specific example, the second maximum height H _{2 of} the second refining plates 26B, 36B, as 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 up to about 1.5 mm. In another specific example, the second maximum height H _{2 of} the second refining plates 26B, 36B, as 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. In the following examples, the first refining plates 26A, 36A and the second refining plates 26B, 36B may include a width W ₂₆ extending between the side edges of the respective refining plates 26A, 36A, 26B, 36B and ranging from about 2 mm to about 8 mm.

Each of the first refining plates 26A, 36A extends from the radially inward position P ₁ on the refining surface 24, 34 to the first radially outward position P ₂ on the refining surface 24, 34. Each of the second refining plates 26B, 36B extends to the second radially outward position P ₃ on the refining surface 24, 34. The second radially outward position P ₃ may be closer to the most distal portion, for example, the radially outer edge 27, 37, of the refining body 22, 32 than the first radially outward 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 include a longitudinal length L ₁ of about 0.6 cm to about 10 cm, and preferably from about 2 cm to about 10 cm.

In some embodiments, the second refining plates 26B, 36B may be integral with the first refining plates 26A, 36A, as shown in FIG. 4A, 5A and 6A such that the second refining plates 26B, 36B extend from the first radially outward position P ₂ to the second radially outward position P ₃ . According to a specific embodiment, the second refining plates 26B, 36B may have a continuous downward slope from the first radially outward position P ₂ to the second radially outward position P ₃ . As shown in FIG. 6A, the 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 particular embodiment, the second refining plates 26B, 36B may extend substantially horizontally from the first radially outward position P ₂ to the second radially outward position P ₃ as indicated by the dashed line in FIG. 6A such that the second refining plates 26B, 36B are at the second maximum height H2 for substantially the entire length in the longitudinal direction L _{1 of} the second refining plates 26B, 36B. According to other embodiments (not illustrated), the first refining plates 26A, 36A may be radially spaced apart 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 adjacent first refining plates 26A, 36A. The baffles 29, 39 serve to deflect 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 including wood fibers enters the frame 66, for example the inlet 16, of the refiner 10, the first refining plates 26A, 36A are configured to refine the wood fibers in the wood pulp slurry while as the second refining plates 26B, 36B are configured to grind or separate the fiber bundles. Refining can be used to break up and break up small fiber clumps, induce external or internal fibrillation to effect fiber bonding, and/or cut a significant number of long wood fibers in the pulp slurry such that long wood fiber lengths are reduced. However, the refining process also causes some of the wood fibers to re-form small dense fiber bundles ("flakes"), particularly in the case of refining long fibers such as softwood fibers. Fiber bundles can adversely affect tensile strength, formation, and other parameters of the final paper product, initiate the formation of wood pulp filaments that clog downstream components, and/or inhibit fluid/water leakage from the fibers during the manufacture of paper products. Thus, the flakes must be broken down after refining in a process termed "defibration". As used herein, the term "defibration" is used to refer to the process of breaking down the fiber bundles that form during refining. When the refining involves a conventional wood pulp refiner, the defibrillation typically occurs in one or more downstream refiners, which are often operated at low power and are cone mill type refiners or deflocculators. The use of separate refiners or deflocculators adds to the cost and complexity of the system. In addition, the cone mill type refiners and associated piping and tanks and the downstream machine pool can accumulate residual amounts of fibers from prior batches and allow continuous fiber bundle formation. Processing in cone mill type refiners can degrade fiber properties when co-refining mixed grade pulp slurries. The authors 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 Hi of the first refining plates 26A, 36A is greater than the second maximum height H ₂ , which means that the wood fibers are subjected to high intensity shear and compression forces as the fibers pass through a portion of the refining space 60 that is at least partially determined 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 Fig. 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 the radially inward position Pi on the refining surface 24, 34 to the first radially outward position P2 on the refining surface 24, 34 may at least partially define the refining zone. In some examples, the radially inward position 23, 33 of the respective refining body 22, 32 may define the start of the refining zone. When the fibers being refined pass into a portion of the refining space 60 that is at least partially defined by the second refining grooves 28B, 38B (for example, from approximately the first radially outward position P ₂ to approximately the second radially outward 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 the first radially outward position P ₂ to the second radially outward position P ₃ on the refining surface 24, 34 may at least partially define a zone defibration. The authors believe that reducing the force applied to the fibers in the defibration zone leads to the refinement of the fiber bundles that are formed during refining, without additional refining or with 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 defibration zone around the radially outer portion (not indicated by a separate number) of the first and second refining bodies 22, 32. The authors believe that the second maximum height θ of the second refining plates 26B, 36B should be at least about 0.35 mm less than the first maximum height H _{1 of} the first refining plates 26A, 36A to stop fiber refining and start defibration. The refining zone may be 60% or more of the total area defined by the sum of the refining and defibration zones on each refining surface 24, 34.

According to the embodiments shown in FIG. 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 the same as 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 less radially outward. The first refining plates 26A', 36A' may be separated from each other by first refining grooves 28A', 38A', and the second refining plates 26B', 36B' may be separated from each other by 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. 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 F3 _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 F4 of the adjacent 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 H ₄ may be substantially equal to the second maximum height H ₂ . The minimum height difference between H ₃ and H ₄ is represented 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 stepped 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 of about 2 mm to about 6 mm.

In some examples, the fourth maximum height H ₄ may be at least 0.35 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 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, as measured from the bottom F _{3 of} the adjacent third refining groove 28C, 38C, may be from about 4 mm to about 10 mm. In a specific example, the fourth maximum height Ω 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 up to about 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. In the following examples, the third refining plates 26C, 36C and the fourth refining plates 26D, 36D may include a width (not indicated by individual numbers) extending between the side edges of the respective refining plates 26C, 36C, 26D, 36D and ranging from about 2 mm to about 8 mm .

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 outward position P _2' on the refining surface 24, 34. Each of the second refining plates 26B', 36B' extends to the second radially outward position P _3' on the refining surface 24, 34. Each of the third refining plates 26C, 36C extends to the third radially outward position P4 on the refining surface 24, 34. Each of the fourth refining plates 26D, 36D extends to the fourth radially outward positions P ₅ on the refining surface 24, 34. The fourth radially outward position P ₅ may be closer to the outermost part, for example, the radially outer edge 27, 37 of the refining body 22, 32 than the first, second and third radially outward positions P _{2 '} , R _3' and R ₄ . The fourth refining plates 26D, 36D may include a longitudinal length L ₂ of about 0.6 cm to about 10 cm, and preferably about 2 cm to about 10 cm.

In some embodiments, the second refining plates 26B', 36B' may be integral with the first refining plates 26A', 36A' as shown in FIG. 4B, 5B and 6B such that the second refining plates 26B', 36B' extend from the first radially outward position P _2' to the second radially outward position P _3' . In some embodiments, as shown 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 outward position P _3' to the third radially outward 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 outward position P4 to the _fourth radially outward position P5. According to a particular embodiment, the second refining plates 26B', 36B' may have a continuous downward slope from the first radially outward position P _2' to the second radially outward position P ₃ . As shown in FIG. 6B, the second refining plates 26B', 36B' may include a longitudinal length L ₁ of about 0.6 cm to about 10 cm, and preferably about 2 cm to about 10 cm. The height of the second refining plates 26B', 36B' can continuously decrease over almost the entire length in the longitudinal direction Li from the second maximum height H ₂ to the second minimum height H _2' . According to another particular embodiment, the second refining plates 26B', 36B' may extend substantially horizontally from the first radially outward position P _2' to the second radially outward position P _3' as indicated by the dashed line in FIG. 6B such that the second refining plates 26B', 36B' are at the second maximum height H ₂ for 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 the third radially outward position P ₄ to the fourth radially outward position P ₅ . As shown in FIG. 6B, the height of the fourth refining plates 26D, 36D may continuously decrease over substantially the entire length in the longitudinal direction L ₂ from the fourth maximum height H ₄ to the fourth minimum height H _4' . According to another particular embodiment, the fourth refining plates 26D, 36D may extend substantially horizontally from the third radially outward position P ₄ to the fourth radially outward position P ₅ as indicated by the dashed line in FIG. 6B such that the fourth refining plates 26D, 36D are at the fourth maximum height H ₄ for substantially the entire length in the longitudinal direction L _{2 of} the fourth refining plates 26D, 36D. According to other embodiments (not illustrated), the third refining plates 26C, 36C may be radially spaced apart 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 refine wood fibers and the second refining plates 26B', 36B' in FIG. 4B, 5B and 6B are configured to refine the 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 refine 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, parts of the refining space 60 which are at least partially defined by the first refining grooves 28A', 38A' and the third refining grooves 28C, 38C and extend from the radially inward position P _1' to the first radially outward position P _{2 '} and from the second radially outward position P _3' to the third radially outward 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 outward position P _2' to the second radially outward position P _3' and from the third radially outward position P ₄ to the fourth radially outward position of P ₅ on the refining surface 24, 34 may at least partially define the first and second defibration zones, respectively, as described herein. 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 less than the first maximum height Hi of the first refining plates 26A', 36A' in order to stop fiber refining and start defibrillation. Similarly, the authors believe that the fourth maximum height H _{4 of} the fourth refining plates 26D, 36D should be at least about 0.35 mm less than the third maximum height H _{3 of} the third refining plates 26C, 36C in order to stop fiber refining and start defibrillation. The first and second refining zones may be 60% or more of the total area determined 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 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 near and opposite the second refining element 30 (see Fig. 1). According to the embodiment shown in FIG. 8, the refining body of the present invention, such as the first refining body 22, is paired with the 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 be match the first and second refining plates 26A, 26B and the first and second refining grooves 28A, 28B as described herein with respect to FIG. 4A, 4B, 6A, 6B and 7. It should be understood that the features described in FIG. 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). Conventional refining body 132 includes a conventional refining plate 136 that has the same height over substantially the entire longitudinal length of the refining plate 136 and refining groove 138. In other embodiments (not illustrated), a non-rotating stator element, such as first refining element 20, may include traditional refining plates that are of 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 according to 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 where 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 traditional refining plate 136, and G2 is greater than G ₁ . In examples where the second refining plate 26B extends substantially horizontally (shown 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 G3 is more than G ₁ . As shown in FIG. 8, according to embodiments in which one of the second refining plates, such as the second refining plate 26B, is inclined, the distance between the outer surface S26B of the second refining plate 26B and the outer surface S ₁₃₆ of the conventional refining plate 136 may be continuously increased over at least part of the length in the longitudinal direction (not indicated; see Fig. 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 shown in FIG. 9, one refining body of the present invention, such as the first refining body 22, is paired with another refining body of the present invention, such as the 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 FIG. 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, to which the first and second refining plates 36A, 36B and the first and second refining grooves 38A, 38B as described herein with respect to FIG. 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 the 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 have a continuous downward slope, a 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 greater 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 9 in dashed lines), a gap G ₅ 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, with G ₅ being 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. plate 26B and the outer surface S _36B' of the second refining plate 36B, and G ₆ is greater than G ₁ . In some specific examples, G ₄ is greater than G ₅ and G ₅ is greater than G ₆ .

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 may continuously increase along at least a portion 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, for example, 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 S _26B , S _36B of the second refining plates 26B, 36B can be increased from the minimum distance corresponding to the gap G ₆ to the maximum distance corresponding to the second gap G ₄ .

In all embodiments illustrated in FIG. 8 and 9, when the rotating refining element (e.g. the first refining element 20; see Fig. 1) rotates with respect to the stationary refining element (e.g. the second refining element 30/130; see Fig. 1), the wood pulp slurry, including wood fibers, enters the frame 66, for example, the inlet 16, 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 wood fibers as described herein. The authors believe that the first gap G ₁ should be less than about 0.9 mm, and preferably from about 0.2 mm to about 0.9 mm, in order to carry out refining.

In addition, as shown in FIG. 8, when wood fibers pass 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 refining body 132, such that the inventors believe that refining is stopped 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 where 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 from about 0.9 mm to about 1.5 mm for defibration to occur.

As shown in FIG. 9, when the wood fibers enter the 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 interact 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 body 32 is enlarged to one of the gaps G ₄ , G ₅ or G ₆ , so that refining is stopped and defibration begins. The authors believe that the first gap G ₁ should be less than about 0.9 mm and preferably from about 0.2 mm to about 0.9 mm for refining to occur, and that the gaps G ₄ , G ₅ , G ₆ should be from about 0.9 mm to about 1.5 mm for defibration to occur.

As shown in FIG. 1, 6A, 6B, 8 and 9, 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 to one of the first and second refining elements 20, 30, for example, using a second motor 76, which is attached to the movable support frame 68 via 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 screw jack. For a double disc refiner 10, the second refining element 30 moves as described above, ie. as the jackscrew rotates in the first direction, it causes the movable support frame 68 and the fourth refining element 50 to move inward towards 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 with respect to the first refining element 20 using a second motor 76 (operated manually or through a controller/processor attached to the second motor 76) and a jack screw such that the amount of power that is required to be input/produced using the first motor 74 (manually controlled or through a controller/processor attached to the first motor 74) operating at a given rotational speed to process a certain amount of wood pulp flowing through refining space 60 is maintained at a given input power level, which power level is monitored by an operator or controller/processor that controls first motor 74. For example, if wood pulp is moving through refining space 60 with a diameter of 20 inches in low consistency refiner Andritz® Twinflo IIIB at a flow rate of 151 gpm, the first motor 74 runs at a constant speed of 800 rpm, the second motor 76 is adjusted to move the second refining element 30 relative to the first refining element. 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 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 wood pulp suspension flowing through the refining space 60), which acts on the refining bodies 22, 32/132. For example, when a small load is applied to the refining bodies 22, 32/132, the refining of the wood fibers may stop and defibration may begin almost immediately after the fibers have passed 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, during the movement of wood fibers passing the first radially outward position P ₂ /P _2' and/or the third radially outward position P4, as shown in FIG. 6A and 6B. When the refining bodies 22, 32/132 are subjected to a low load, refining of the wood fibers can continue to some extent over 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 subjected to a 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 a continuous downward slope may be particularly advantageous to ensure that a sufficient distance between the refining plates 26B/26B' and 136/36B/36B' is achieved over at least a portion of the refining space 60, which is at least partially defined by the second refining grooves 28B. /28V', 38V/38V' to ensure that refining is stopped and defibration occurs. In addition, the refining surfaces 24, 34 of the refining bodies 22, 32 may be subject to wear and tear over time. In particular, the first and third refining plates 26A/26A', 26C, 36A/36A', 36C, which carry out the main high-intensity high-energy refining, can wear faster than the second and fourth refining plates 26B/26B', 26D, 36B/36B. ', 36D, which perform defibrillation, which is generally less intensive and low energy compared to refining. The position of the refining bodies 22, 32/132 can be adjusted, as described herein, to maintain the first gap G1 between the first and third refining plates 26A/26A', 26C, 36A/36A', 36C at a substantially constant level when the respective outer surfaces S _26A , S _36A begin to wear out. 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 adjustable. Thus, the authors 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 slanted allow transition shifting. 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 refining plates 26A/26A', 26C, 36A/36A', 36C.

In FIG. 10 and 11 are plan views of parts 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 the refining elements, for example, the first and second refining elements 20, 30, respectively, as described herein, for use in a wood pulp refiner such as 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, can be associated with the 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, such as the first refining element 20, including the 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, such as a second refining element 30 including a second refining body 32', may be fixedly attached to a support 70 which rotates with a shaft 72 and defines a rotor that is connected to the main support frame such that the rotation of the rotor provides movement the second refining element 30 with respect to the first refining element 20. In addition, there may be third and fourth refining elements (not illustrated) 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 (includes a plurality of sections 22A'-22C, which can be bolted or otherwise connected to each other to form a disc-shaped refining body 22', including 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 not shown in Fig. 10, it should be understood that other sections (not numbered) of the first refining body 22' will similarly include refining plates 26' and refining grooves 28'. The refining plates 26' extend radially outward from the radially inward 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 include one or more radially extending sector segments, including at least one first sector segment 22V-1 and alternating At least one second sector segment 22V-2.

As shown in FIG. 11, the second refining body 32' includes a respective plurality of sections 32A'-32C which may be bolted or otherwise connected to each other to form a disc-shaped refining body 32' including a radially outer edge 37'. Each section 32A'-32C includes a plurality of oblong refining plates 36' separated from each other by refining grooves 38'. Although not shown in FIG. 11, it should be understood that other sections (not numbered) of the second refining body 32' will likewise include refining plates 36' and refining grooves 38'. The refining plates 36 (extend radially outward from the radially inward 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, including 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 include a structure that is substantially similar to 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 includes one or more sections 22A'-22C, 32A'-32C, including at least one radially extending sector segment, for example, 22B-1 and 32B-1, refining plates 26', 36', which have one or several characteristics in which they differ from the refining plates 26', 36' in an adjacent radially extending sector segment, for example 22B-2 and 32B-2, respectively. In FIG. 12A and 12B are partial sectional views, with the first and second refining bodies 22', 32' in FIG. 10 and 11 are at a distance and located near 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 22B-1 of the first refining body 22' (also referred to herein as the first refining surface), is at a distance and located near 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, the 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 proximate 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 first refining grooves 28-1 and may include 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 include a third maximum height H _3' extending upward from the bottom F _{3' of} the respective 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 include 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 include a fourth maximum height H _4' extending upward from the bottom F _{4' of} 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 respective sector segment 22B-1, 22B-2, 32B-1, 32B-2 may have the same height relative 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' , as measured from the bottom F _{2' of} the adjacent second refining groove 28-2, may be at least 0.35 mm less than the first maximum height H _1' . In other examples, the second maximum height H _2' as measured from the bottom F _{2' of} the adjacent second refining groove 28-2 may be at least 0.70 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, as measured from the bottom F _{1' of} the corresponding adjacent first refining groove 28-1, may be from about 4 mm to about 10 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, and their difference may be from about 0, 35 mm to approximately 1.5 mm H _1' . 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 about 0.7 mm to about 1.5 mm. In the following examples, the first refining plates 26-1 and the second refining plates 26-2 may include a width between the side edges of the respective refining plates 26-1, 26-2 of about 2 mm to about 8 mm (not illustrated; see fig. Fig. 7). The fourth maximum height H _{4' of} the fourth refining plates 36-2, which the second maximum height H _2' may correspond to, may be less than the third maximum height H _{3' of} the third refining plates 36-1, which the first maximum height H _1' may correspond to.

As shown in FIG. 1, 10, 11, 12A, and 12B, when the second refining element 30 rotates with respect 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'. When the wood pulp slurry enters the frame 66, for example 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 amount 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 located opposite the second refining plates 26-2, including the second maximum height H _2' , so that the second and fourth refining plates 26-2 and 36-2 crush or separate a plurality of wood fiber bundles into wood pulp slurry as described herein. Low intensity refining may 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 surface the surface 34-2 of at least one fourth sector segment 32B-2 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'.

As shown in FIG. 10 and 11, one or each of several sections 22A'-22C, 32A'-32C of the respective refining bodies 22', 32' may in some examples include 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, 22V-1, 22V-3 and 32V-1, 32V-3, may include 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 include refining plates with another of the first and second maximum heights H _1' , H _2' , wherein the second maximum height H _2' is less than the first maximum height H _1' . For example, segments 22B-1, 22B-3 may include first refining plates 26-1, segments 32B-1, 32B-3 may include third refining plates 36-1, segment 22B-2 may include 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 include only two refining plate segments, or may include 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 includes 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', may be paired with a refining body including conventional refining plates, for example refining plates, all of which have the same height.

The authors believe that the gap between the opposing first and third refining plates 26-1, 36-1 must be less than about 0.9 mm and preferably from about 0.2 mm to about 0.9 mm for refining to occur, and that the gap between the opposing second and fourth refining plates 26-2, 36-2 must be between about 0.9 mm and about 1.5 mm for defibration to occur.

In FIG. 13 and 14 are plan views of parts 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 the refining elements, e.g., refining elements 20, 30, respectively, as described herein, for use in a wood pulp refiner, such as the disc refiner 10 illustrated. in fig. 1. Each of the refining elements 20, 30, including the first and second refining bodies 222, 232, respectively, can be associated with the main support frame, including a fixed support frame 66 attached to the first body section 12, and a movable support frame 68. One a refining element, such as a first refining element 20 including a first refining body 222, may be fixedly attached to the support frame 66 of the refiner 10, which defines a non-rotating stator element. Another refining element, such as a second refining element 30 including a second refining body 232, may be fixedly attached to a support 70 which rotates with a shaft 72 and defines a rotor that is connected to the main support frame such that the rotation of the rotor drives the second refining element 30 with respect to the first refining element 20.

As shown in FIG. 13, the first refining body 222 includes a plurality of sections (not individually numbered; see FIGS. 2 and 3) that can be bolted or otherwise connected to each other to form a disc-shaped refining body 222 including 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 the radially inward position 223 towards the radially outer edge 227 of the first refining body 222. The first refining plates 226 may be tilted at various angles, as shown in Fig. 13, and each section of refining body 222 may include one or more segments (not numbered) 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 the other sections (not numbered) of the first refining body 222 will likewise include refining plates 226, refining grooves 228, and teeth 400.

As shown in FIG. 14, the second refining body 232 includes a plurality of sections (not individually numbered; see FIGS. 2 and 3) that can be bolted or otherwise connected to each other to form a disc-shaped refining body 232 including 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 the radially inward position 233 towards the radially outer edge 237 of the second refining body 232. The second refining plates 236 may be tilted at different angles, as shown in Fig. 14, and each section of refining body 232 may include one or more segments (not numbered) of refining plates 236 that are inclined in various 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 indicated by numbers) of the second refining body 232 will likewise include refining plates 236, refining grooves 238, and teeth 400. Also, although not discussed in detail herein, the structure of the refining surfaces 44, 54 , respectively, of the third and fourth refining bodies 42, 52 in FIG. 1 may include a structure that is substantially similar to 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 in FIG. 13 and 14, respectively. In FIG. 17 is a partial sectional view of the first refining plate 226 and barb 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 spaced apart from and located near and opposite the second refining body 232, which defines a refining space 260 between them. As shown in FIG. 15-17, the first refining surface 224 includes first refining plates 226, which are separated from each other by first refining grooves 228, and the second refining surface 234 includes second refining plates 236, which are separated from each other by second refining grooves 238. One or both of the first and 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 the radially inward position P ₁₀₀ to the first radially outward position P ₂₀₀ on the respective first and second refining surfaces 224, 234. In some examples, the radially inward position P ₁₀₀ may include a position at or near corresponding radially internal position 223, 233 (see Fig. 13 and 14). The first and second refining plates 226, 236 may include 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.

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 outward position, such as P ₄₀₀ , on the first refining surface 224 , wherein the third radially outward position P ₄₀₀ is closer to the most distal portion, such as the radially outer edge 227, of the first refining body 222 than the first radially outward position P ₂₀₀ of the first refining plates 226. The second refining surface 234 includes second teeth 400A, 400C that 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 outward position, such as P ₃₀₀ or P ₅₀₀ , on the second refining surface. 234, and the second and fourth radially outward positions P ₃₀₀ , P ₅₀₀ are located closer to the outermost part, 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, teeth 400A-400C may be arranged in concentric rings and may extend substantially perpendicular to each other from respective refining surfaces 224, 234. The ring including first teeth 400B is spaced from the radially outer edge RO ₂₂₆ of the first refining plates 226 and separated from it by a first substantially flat region 282 and separated from the radially outer edge 227 of the refining body 222 by a second substantially flat region 284. The ring including the second teeth 400A is spaced from the radially outer edge RO ₂₃₆ of the second refining it by a first substantially flat region 286 and also separated from the annulus including the second teeth 400C by a second substantially flat region 288. According to the embodiment shown 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 includes two concentric rows/rings of second teeth 400A, 400C, with the first and second teeth 400A -400C are located on the respective refining surfaces 224, 234 such that the first teeth 400B engage with the second teeth 400A, 400C. According to other embodiments (not illustrated), the first refining surface 224 may include two or more concentric rings of teeth, and the second refining surface 234 may include one concentric row of teeth or three or more concentric rings of teeth. In all embodiments, one of the refining bodies will include one ring of teeth less than the other refining body, and the teeth are located on each refining body such that the teeth of one refining body engage with 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 shape and/or size known in the art. As illustrated with respect to barb 400A in FIG. 17, in some examples, each of the first and second prongs 400A-400C may have a substantially pyramidal or trapezoidal shape with a base 402, a radially inward face 404, a radially outward face 406, sides (not individually numbered) slanted slightly inward in direction toward the central axis (not numbered) of prong 400A, and a generally flat outer surface 408. The radially inner and outer faces 404, 406 of each prong 400A-400C may slope from the base 402 toward the corresponding outer surface 408. The outer surface 408 of each prongs 400A-400C may be substantially parallel to the plane of a corresponding substantially flat region 282, 284, 288 that is opposite prongs 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 include 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 indicated by a number) in the longitudinal direction, i. 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. (not indicated by a number) in the circumferential direction, which is substantially equal to the sum of the width, for example, W ₂₂₆ , W ₂₃₆ , 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 about 6 mm. For example, the base 402 of the teeth 400A-400C may be at least about 10 mm in the circumferential direction. In other examples, the base 402 of the teeth 400A-400C may be approximately 10 mm to 20 mm in the circumferential direction. In addition, one or more of the radially inner and outer faces 404, 406, or the sides of one or more teeth 400A-400C, may include one or more radially extending protrusions that can interfere with the interaction of teeth 400A-400C with wood fibers to separate the tufts. wood fibers. Barbs 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 include a first height H ₁₀₀ extending upward from the bottom F _{100 of} adjacent first refining groove 228, and the second refining plates 236 include a second height H ₂₀₀ extending upward from the bottom F ₂₀₀ of 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 be from about 4 mm to about 10 mm. The first and second refining bodies 222, 232 are spaced apart from each other 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 usually flat outer surfaces 408 of teeth 400A-400C and a corresponding one of the substantially flat regions 282, 284, 288 that is opposite tooth 400A-400C, where G ₂₀₀ may be greater than G ₁₀₀ . In some examples, the height (not numbered) of the teeth 400A-400C extending upward from the adjacent respective first or second refining grooves 228, 238 may be approximately 8 to 10 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, such as in the direction of arrow A in FIG. 1 with a portion of the radially inner or outer face 404, 406 of adjacent teeth 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 may be substantially 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, when the wood pulp slurry enters the refiner frame 10, such as the 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 inward position P ₁₀₀ to approximately the first radially outward position P ₂₀₀ . The first and second refining plates 226, 236 interact with each other to refine a significant amount of wood fibers in the wood pulp, as described herein. The inventors believe that the first gap G ₁₀₀ should be less than about 0.9 mm, and preferably from about 0.2 mm to about 0.9 mm, for refining to occur. The refined wood fibers then extend 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, such as from approximately the first radially outward position P ₂₀₀ to approximately the fourth radially outward position P ₅₀₀ . The authors believe that the second and third gaps G ₂₀₀ and G ₃₀₀ should be from about 0.9 mm to about 1.5 mm for defibration to occur. Prongs 400A-400C are configured to grind or separate a plurality of wood fiber bundles in the wood pulp slurry, as described herein. The gap G ₂₀₀ is greater than G ₁₀₀ and thus the inventors believe that refining is stopped and defibration begins at approximately the first radially outward 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, may be subject to wear and tear from over time. To compensate for this wear, the space between the first and second refining elements 20, 30, including the first and second refining bodies 222, 232, respectively, can be re-adjusted, as described herein, such that the first gap G ₁₀₀ remains substantially constant. This adjustment of the first and second refining bodies 222, 232 can cause the second gap G ₂₀₀ to decrease when the refining plates 226, 236 perform the refining function more intensively and generally wear faster than the teeth 400A-400C. This wear difference may play a role in the selection of teeth 400A-400C (e.g., type(s) of metal used for teeth 400A-400C, initial second gap size G ₂₀₀ , 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 when the wood fibers enter a portion of the refining space 260 that is at least partially defined by the 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 ₃ 00 is less than the second gap G ₂₀₀ .

In all embodiments described herein, refiner 10 in FIG. 1, a controller (not illustrated) may be connected to receive data transmitted by a fiber analyzer (for example, the Valmet® MAP wood pulp analyzer from Valmet Corp.) in relation to one or more fiber properties measured at one or more points downstream relative to refiner 10, such as the number, size and other parameters of fiber bundles (also referred to as "wide partially separated fiber bundles"), fibrillation, Canadian standard pulp freeness, fiber length, fiber width, curl, crimp, roughness, amount of fine fibers, and etc. Based on this data, the controller may regulate 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 authors believe that based on these data, the controller may also increase or decrease the speed of rotation of one or more rotating rotary elements of the refiner 10 (for example, the second and third refining elements 30, 40). In other examples, the controller may adjust the operation of the refiner 10, including changing the size of the refining gap G ₁ , G ₁₀₀ and the gap 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, eg 1000 ppm, of fiber bundles having defined dimensions, eg a width of about 150 to 2000 microns and a length of 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 adjust the operation of one or more of the 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 according to the present invention can only be installed in the final refiner of this sequence, and in other examples, the refining elements 20, 30, 40, 50 according to the present invention can be installed in two or more number of refiners.

In FIG. 18 is a flow chart illustrating an exemplary process for processing wood fibers. While reference is made to components of refiner 10 in FIG. 1, it should be understood that the method is not limited to this structure. The method may begin at step 500 of providing a refiner 10 including at least a first pair of refining elements 20 and 30, 40 and 50. At least one pair of refining elements may include a first refining element 20 including a first refining body 22 including a first refining surface 24 and a second refining element 30 including a second refining body 32 including 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 having 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 the second element 36 separated by refining grooves of the second element 38. The first refining element 20 may be at a distance from the second refining element 30, which defines the refining space 60 between them. At least some of the refining plates of the second element 36 may be positioned so as 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 refining plates of the second element 36 and second refining plates 26B.

The method may be continued 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 in step 510 and introducing a pulp slurry including woody fiber, into the refiner 10 such that the slurry passes through the refining space 60 at 520. At 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 , so that the gap G ₂ , G ₃ , G ₄ , G ₅ , G ₆ between the refining plate part 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 gap G ₂ , G ₃ , G ₄ , G ₅ , G ₆ , and thereafter about can be completed.

Although specific embodiments of the present invention have been illustrated and described, it should be understood that various changes and modifications can be made without deviating from the idea and departing from the 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 (66)

1. A refining element for a wood pulp refiner, the refining element comprising: refining body, including refining surface, including: first refining plates separated by first refining grooves, each of the first refining plates extending from a radially inward position on the refining surface to a first radially outward position on the refining surface; second refining plates separated by second refining grooves, each of the second refining plates extending to a second radially outward position on the refining surface, the second refining plates have a length in the longitudinal direction of 0.6 cm to 10 cm, and the second radially outward position is closer to the most distal portion of the refining body than the first radially outward position, wherein the first refining plates have a first maximum height extending upward from the bottom of an adjacent first refining groove and the second refining plates have a second maximum height extending upward from the bottom of an adjacent second refining groove grooves, and the second maximum height is at least 0.35 mm less than the first maximum height; and wherein 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 first maximum height of the first refining plates, as measured from the bottom of the adjacent first refining groove, is between 4 mm and 10 mm. 3. The refining element according to claim 2, wherein the second maximum height of the second refining plates, as measured from the bottom of the adjacent second refining groove, is less than the first maximum height and their difference is between 0.35 mm and 1.5 mm. 4. The refining element according to claim 2, wherein the second maximum height of the second refining plates, as measured from the bottom of the adjacent second refining groove, is less than the first maximum height and their difference is between 0.7 mm and 1.5 mm. 5. The refining element according to claim. 1, in which the length in the longitudinal direction of the second refining plates is from 2 cm to 10 cm. 6. The refining element of 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 outward position to the second radially outward position. 7. The refining element of claim. 6, wherein each of the second refining plates has a continuous downward slope from the first radially outward position to the second radially outward position. 8. The refining element according to claim 1, wherein the first and second refining plates have a width between side edges of 2 mm to 8 mm. 9. The refining element according to claim 1, wherein at least some of the first refining grooves are provided with baffles. 10. The refining element according to claim 1, further comprising: third refining plates separated by third refining grooves, each of the third refining plates extending to a third radially outward position on the refining surface; fourth refining plates separated by fourth refining grooves, each of the fourth refining plates extending to a fourth radially outward position on the refining surface, the fourth refining plates have a length in the longitudinal direction of from 0.6 cm to 10 cm, and the fourth radially outward position is closer to the most distal portion of the refining body than the third radially outward position, the third refining plates have a third maximum height extending upward from the bottom of the adjacent third refining groove, and the fourth refining plates have a fourth maximum height extending upward from the bottom of the adjacent fourth refining groove , and the fourth maximum height is at least 0.35 mm less than the third maximum height; and wherein the third refining plates are configured to refine wood fibers, and the fourth refining plates are configured to refine 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 outward position to the third radially outward position, and the fourth refining plates are integral with the third refining plates. plates such that the fourth refining plates extend from the third radially outward position to the fourth radially outward position. 12. Wood pulp refiner, comprising: frame; at least a first pair of refining elements, including: the first refining element associated with the frame and including the first refining body, including the first refining surface, including: first refining plates separated by first refining grooves, each of the first refining plates extending from a radially inward position on the refining surface to a first radially outward position on the refining surface; and second refining plates separated by second refining grooves, each of the second refining plates extending to a second radially outward position on the refining surface, the second refining plates having a length in the longitudinal direction of from 0.6 cm to 10 cm, and the second radially outward position is closer to the most distal part of the refining body than the first radially outward position, and the first refining plates have a first maximum height extending upward from the bottom of the adjacent first groove, and the second refining plates have a second maximum height extending upward from the bottom of the adjacent second groove, wherein the second maximum height is at least 0.35 mm less than the first maximum height; a second refining element associated with the frame and including a second refining body, including a second refining surface, including refining plates of the second element, separated by refining grooves of the second element, the first refining element being at a distance from the second refining element, which defines the refining space between them; and a rotor associated with the frame and attached to one of the first refining element and the second refining element, so that the rotation of the rotor moves one of the first and second refining elements with respect to the other; wherein, when the wood pulp slurry including wood fibers enters the frame, the wood pulp slurry passes through the refining space so that the wood fibers in the wood pulp slurry are refined and the plurality of wood fiber bundles in the wood pulp slurry are separated. 13. The wood pulp refiner of claim 12, wherein the second maximum height is at least 0.7 mm less than the first maximum height. 14. The wood pulp refiner according to claim 12, wherein the longitudinal length of the second refining plates is between 2 cm and 10 cm. 15. The wood pulp refiner according to claim 12, wherein the refining plates of the second element include: third refining plates extending from a radially inward position on the second refining surface to a first radially outward position on the second refining surface; fourth refining plates extending to a second radially outward position on the second refining surface, the second radially outward position being closer to the most distal portion of the second refining body than the first radially outward position, the third refining plates having a third maximum height extending upward from the bottom adjacent groove, and the fourth refining plates have a fourth maximum height extending upward from the bottom of the adjacent groove, the fourth maximum height being at least 0.35 mm less than the third maximum height. 16. The wood pulp refiner of claim 12, wherein the first refining element is a non-rotating stator element and the second refining element is a rotating rotor element. 17. Method for processing wood fibers, including: providing a refiner including at least a first pair of refining elements, including: a first refining element, including a first refining body, including a first refining surface, including: first refining plates separated by first refining grooves, each of the first refining plates extending from a radially inward position on the refining surface to a first radially outward position on the refining surface, and having a first maximum height extending upward from the bottom of the adjacent first refining groove, and second refining plates separated by second refining grooves, each of the second refining plates extending to a second radially outward position on the refining surface and having a second maximum height extending upward from the bottom of the adjacent second a refining groove, the second radially outward position being closer to the most distal portion of the refining body than the first radially outward position; second refining element, including a second refining body, including a second refining surface, including refining plates of the second element, separated by refining grooves of the second element, the first refining element being at a distance from the second refining element, which defines the refining space between them, and at the same time at least at least part of the refining plates of the second element is opposite the first refining plates, and a part of the refining plates of the second element is opposite the second refining plates, so that the first gap is defined between the first part of the refining plates of the second element and the first refining plates, and the second gap is defined between the second part refining plates of the second element and second refining plates, the second gap being greater than the first gap; 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 wood pulp slurry comprising 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, as the slurry is supplied, so that the gap between a portion of the refining plates of the second element and the second refining plates is from 0.9 mm to 1.5 mm , wherein at least some of the wood fiber bundles passing through the gap are separated. 18. The method of claim 17, wherein the second refining plates have a longitudinal length of 0.6 cm to 10 cm and the second maximum height is at least 0.35 mm less than the first maximum height. 19. The method according to claim 18, wherein the length in the longitudinal direction of the second refining plates is from 2 cm to 10 cm. 20. The method of claim 17, wherein the refining plates of the second element comprise: third refining plates; and fourth refining plates, wherein the third refining plates have a third maximum height extending upward from the bottom of the adjacent groove, and the fourth refining plates have a fourth maximum height extending upward from the bottom of the adjacent groove, the fourth maximum height being at least 0.35 mm less than the third maximum height. 21. A refining element for a wood pulp refiner, the refining element comprising: refining body, including a plurality of radially passing sector segments, including: at least one first sector segment comprising a first refining surface including first refining plates separated by first refining grooves, the first refining plates having a first maximum height extending upward from the bottom of an adjacent first refining groove; at least one second sector segment, including a second refining surface, including second refining plates separated by second refining grooves, wherein the second refining plates have a second maximum height extending upward from the bottom of an adjacent second refining groove, the second maximum height being at least 0.35 mm less than the first maximum height; and wherein the first refining plates are configured to refine wood fibers, and the second refining plates are configured to refine fiber bundles. 22. The refining element according to claim 21, wherein the first maximum height of the first refining plates, as measured from the bottom of the adjacent first refining groove, is between 4 mm and 10 mm. 23. The refining element according to claim 22, wherein the second maximum height of the second refining plates, as measured from the bottom of the adjacent second refining groove, is less than the first maximum height and their difference is between 0.35 mm and 1.5 mm. 24. The refining element according to claim 22, wherein the second maximum height of the second refining plates, as measured from the bottom of the adjacent second refining groove, is less than the first maximum height and their difference is between 0.7 mm and 1.5 mm. 25. Wood pulp refiner, comprising: frame; at least a first pair of refining elements, including: the first refining element associated with the frame and including the first refining body, including a plurality of radially extending sector segments, including: at least one first sector segment, including the first refining surface, including the first refining plates separated by the first refining grooves, the first refining plates having a first maximum height extending upward from the bottom of an adjacent first refining groove, and at least one second sector segment comprising a second refining surface including second refining plates separated by second refining grooves, the second refining plates having a second maximum height extending upward from the bottom an adjacent second refining groove, the second maximum height being at least 0.35 mm less than the first maximum height; a second refining element associated with the frame and including a second refining body, including a refining surface of the second element, including refining plates of the second element, separated by refining grooves of the second element; and the first refining element is at a distance from the second refining element, which defines the refining space between them; a rotor associated with the frame and attached to one of the first refining element and the second refining element so that the rotation of the rotor causes the first and second refining elements to move with respect to each other; and wherein, when the wood pulp slurry including wood fibers enters the frame, the wood pulp slurry passes through the refining space so that the wood fibers in the wood pulp slurry are refined and the plurality of wood fiber bundles in the wood pulp slurry are separated. 26. The wood pulp refiner according to claim 25, wherein the second maximum height of the second refining plates, as measured from the bottom of the adjacent second refining groove, is less than the first maximum height and their difference is between 0.35 mm and 1.5 mm . 27. The wood pulp refiner according to claim 25, wherein the second maximum height of the second refining plates, as measured from the bottom of the adjacent second refining groove, is less than the first maximum height and their difference is between 0.7 mm and 1.5 mm . 28. The wood pulp refiner of claim 25, wherein the second refining body includes a plurality of radially extending sector segments, including: at least one third sector segment comprising a third refining surface including third refining plates separated by third refining grooves, the third refining plates having a third maximum height extending upward from the bottom of an adjacent third refining groove; and at least one fourth sector segment, including a fourth refining surface, including fourth refining plates separated by fourth refining grooves, moreover, the fourth refining plates have a fourth maximum height extending upward from the bottom of an adjacent fourth refining groove, and the fourth maximum height is at least 0.35 mm less than the third maximum height, wherein the third and fourth refining plates define the refining plates of the second element, and wherein the third and fourth refining grooves define the refining grooves of the second element. 29. The wood pulp refiner of claim 25, wherein the first refining element is a non-rotating stator element and the second refining element is a rotating rotor element.

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