Blade segment for a refiner

Abstract

A blade segment (4, 8) for a refiner (1) for refining fibrous material is provided, the blade segment (4, 8) including: a first edge (20) and a second edge (21) opposite the first edge in the direction of a longitudinal axis (LA) of the blade segment (4, 4a, 4b, 8, 8a, 8b); a first side edge (22) and a second side edge (23) opposite the first side edge, the first side edge and the second side edge extending between the first and second edges; and a refining surface (5, 9) including blade bars (26) and blade grooves (27) between the blade bars on a front surface (25) of the blade segment (4, 8). At least one side edge portion (22, 23) includes at least two edge portions (31, 33, 35, 41, 43, 45) arranged away from the direction of the longitudinal axis (LA) of the blade segment (4, 4a, 4b, 8, 8a, 8b) and connected by an elbow (32, 34, 42, 44) between each two edge portions (31, 33, 35, 41, 43, 45).

Description

Technical Field

[0001] The present invention relates to a refiner for refining fibrous materials (refining: refining), and more particularly to a blade segment of a refiner for refining fibrous materials.

Background Art

[0002] Refiners used to refine fibrous materials, such as refiners used in the production of mechanical pulp, or refiners used in any low-consistency refining, typically include two refining elements that face each other and rotate relative to each other, i.e., one or both rotate. The refining elements include a blade bar and a refining surface provided with blade grooves between these blade bars. The blade bar is intended to defiber and refine the material to be refined, and the blade groove is intended to convey the material to be refined forward along the refining surface. The refining surface of the refining element is typically formed from several blade segments fixed to the body of each refining element, and each blade segment includes a respective refining surface formed by the blade bar and the blade groove between these blade bars. Thus, the complete refining surface of the refining element is formed from the refining surfaces of several blade segments fixed adjacent to each other within the refining element. EP Publication No. 3401439 B1 discloses blade segments applicable for use in a refiner for refining fibrous materials.

Summary of the Invention

[0003] It is an object of the present invention to provide not only a novel blade segment for a refiner for refining fibrous materials, but also a novel refiner for refining fibrous materials.

[0004] The present invention is characterized by the features of the independent claims.

[0005] The present invention is based on the idea of forming at least one side edge portion of a blade segment and providing a shape that deviates from the direction of the longitudinal axis of the blade segment.

[0006] When the shape of at least one side edge portion of the blade segment is configured to have a shape that deviates from the direction of the longitudinal axis of the blade segment and the configuration of the opposite side edge portion is selected in cooperation with the configuration of the first-mentioned side edge portion, the configuration provides a longitudinal slit-shaped opening that provides a flow path between adjacent blade segments, and the opening is for supplying the fibrous material to be refined into the refining chamber between the stator and the rotor and discharging the already refined fibrous material from the refining chamber. Therefore, this slit-shaped opening has a center line in a direction deviating from the direction of the longitudinal axis of the blade segment at least for most of the extension of the opening. This has the effect of changing the incident angle between the opening of the rotor and the opening of the stator in the axial direction of the refiner and moving the incident point between the opening of the rotor and the opening of the stator from the axial direction of the refiner. This, in turn, has the effect of being able to reduce the flow fluctuations that may appear in the operation of a prior art refiner.

[0007] Some embodiments of the present invention are disclosed in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Hereinafter, the present invention will be described in more detail by way of preferred embodiments with reference to the accompanying drawings.

Figure 1

Figure 2

Figure 3

Figure 4a

Figure 4b

Figure 5

Figure 6

DETAILED DESCRIPTION OF THE INVENTION

[0009] FIG. 1 is a schematic overall side view of a cross-section of the overall structure of a refiner 1, which can be used to refine fibrous materials, such as wood materials or other fibrous materials containing lignocellulose, suitable for use in the manufacture of, for example, paper or cardboard. The refiner 1 shown in FIG. 1 is of the conical type, but a disk refiner, a conical disk refiner, and a cylindrical refiner can be used here in the same way as in the example. Generally, a refiner includes at least two refining elements positioned substantially opposite each other, at least one of which is rotating, and a refining chamber formed between each two refining elements positioned substantially opposite each other. Hereinafter, a refiner including only one rotatable refining element will be described.

[0010] The refiner 1 in FIG. 1 includes a frame 2 and a stationary fixed refining element 3, i.e., a stator 3, supported by the frame 2. The stator 3 includes two or more stator blade segments 4, and each of these segments 4 includes a blade bar and a blade groove between these stator blade segments 4. The blade bar and the blade groove of each stator blade segment 4 form a refining surface 5 of the respective blade segment 4, whereby the refining surface 5 of each stator blade segment 4 provides a part of the refining surface of the stator 3. The complete refining surface of the stator 3 is formed from the refining surfaces 5 of the required number of blade segments 4 fixed adjacent to each other in the stator 3, thereby providing a complete refining surface 5 extending across the entire circumference of the stator 3. For clarity, both the refining surface of each single stator blade segment 4 and the complete refining surface of the stator 3 are denoted by the same reference numeral 5 in this specification.

[0011] The refiner 1 further includes a rotatable refining element 6 of the refiner 1, i.e., a rotor 6. The rotor 6 includes a hub 7. The rotor 6 further includes two or more rotor blade segments 8 supported by the hub 7, and each rotor blade segment 8 includes a blade bar and a blade groove between these blade bars. The blade bar and the blade groove of each rotor blade segment 8 form a refining surface 9 of the respective blade segment 8, whereby the refining surface 9 of each rotor blade segment 8 provides a part of the refining surface of the rotor 6. The complete refining surface of the rotor 6 is formed from the refining surfaces 9 of the required number of blade segments 8 fixed adjacent to each other in the rotor 6, thereby providing a complete refining surface 9 extending across the entire circumference of the rotor 6. For clarity, both the refining surface of each single rotor blade segment 8 and the complete refining surface of the rotor 6 are denoted by the same reference numeral 9 in this specification.

[0012] The hub 7 of the rotor 6 is connected to the drive motor 10 by the shaft 11, whereby the rotor 6 can rotate relative to the stator 3, for example, in the direction of arrow RD. Thus, the arrow RD indicates the intended rotation direction RD of the rotor 6.

[0013] The refiner 1 may also include a loading device (not shown in FIG. 1 for clarity). The loading device can be used to move the rotor 6 attached to the shaft 11 back and forth, as schematically indicated by arrow A, in order to adjust the refining gap 12 between the stator 3 and the rotor 6, i.e., the size of the refining chamber 12, where the fibrous material is actually refined.

[0014] The fibrous material to be refined is supplied to the refiner 1 via the supply channel 13 in the manner indicated by arrow F. In one embodiment, most of the fibrous material supplied to the refiner 1 passes through the opening 14 of the refining surface 9 of the rotor 6, i.e., enters the refining chamber 12 through the flow path, as schematically indicated by arrow P, where the fibrous material is refined. Further, most of the already refined fibrous material is discharged in turn through the opening 15 of the refining surface 9 of the stator 3, i.e., through the flow path, and enters the intermediate space 16 between the frame 2 of the refiner 1 and the stator 3. From there, the refined material is removed from the refiner 1 via the discharge channel 17, as schematically indicated by arrow D.

[0015] Since the space between the rotor 6 and the frame 2 of the refiner 1 in FIG. 1 is not completely closed, a part of the fibrous material to be supplied to the refiner 1 can be moved into the refining chamber 12 from the right end of the refining chamber 12, that is, from the first end 18 or the inner end 18 of the refiner 1 having a smaller diameter, as can be seen in FIG. 1. Correspondingly, a part of the already refined material is discharged from the left end of the refining chamber 12, that is, from the second end 19 or the outer end 19 of the refiner 1 having a larger diameter, as can be seen in FIG. 1, and a connection to the intermediate space 16 is provided therefrom.

[0016] In the embodiment of the refiner 1 of FIG. 1, only one supply channel 13 is provided, and the channel 13 is arranged at the first end 18 of the refiner 1 having a smaller diameter. The actual embodiment of the refiner can also include a second supply channel arranged at the second end 19 of the refiner 1 having a larger diameter, whereby the discharge channel 17 of the refiner 1 can be arranged, for example, somewhere between the first end 18 and the second end 19 of the refiner 1. In the following, the reference sign 18 and the term first end 18 or the term inner end 18 can denote both the first end 18 or the inner end 18 of the refiner 1 having a smaller diameter and the first end 18 or the inner end 18 of the refining elements 3, 6 or the refining chamber 12 having a smaller diameter. Correspondingly, the reference sign 19 and the term second end 19 or the term outer end 19 can denote both the second end 19 or the outer end 19 of the refiner 1 having a larger diameter and the second end 19 or the outer end 19 of the refining elements 3, 6 or the refining chamber 12 having a larger diameter.

[0017] In addition to the conical refiners disclosed above, it is emphasized that the blade segments of the solutions described herein can also be applied to other types of conical refiners. In addition to conical refiners, the blade segments of the solutions described herein are also applicable to cylindrical refiners and disk refiners, as well as refiners that include both a conical portion and a disk portion.

[0018] Figure 2 is a schematic perspective side view of the stator 3 and rotor 6 of a conical refiner, with the stator 3 shown in cross section. In the circumferential direction of the stator 3, there are several adjacent inner blade segments 4a on the side of the inner end 18 of the stator 3, and a respective number of adjacent outer blade segments 4b on the side of the outer end 19 of the stator 3. The inner segment 4a and the outer segment 4b together provide the blade segment 4. Each inner blade segment 4a is interconnected with a respective outer blade segment 4b at the corresponding circumferential position of the stator 3 to provide the blade segment 4. This segment 4 provides a substantially continuous refining surface 5 between the inner end 18 and the outer end 19 of the stator 3 at each of the respective inner stator blade segments 4a and outer stator blade segments 4b of this blade segment 4. The side edges of the stator blade segments 4a, 4b are implemented such that a slit-like opening 15 that forms a flow path in the circumferential direction of the stator 3 is provided between the interconnected stator blade segments 4.

[0019] Similarly, in the circumferential direction of the rotor 6, there are several adjacent inner blade segments 8a on the side of the inner end portion 18 of the rotor 6, and a respective number of adjacent outer blade segments 8b on the side of the outer end portion 19 of the rotor 6. The inner blade segments 8a and the outer blade segments 8b together provide the blade segment 8. Each inner blade segment 8a is interconnected with a respective outer blade segment 8b at a corresponding circumferential position of the rotor 6 to provide the blade segment 8. This segment 8 provides a substantially continuous refining surface 9 between the inner end portion 18 and the outer end portion 19 of the rotor 6 at each of the inner stator blade segments 8a and the outer stator blade segments 8b of this blade segment 8. The side edges of the rotor blade segments 8a, 8b are implemented such that slit-shaped openings 14 forming a flow path are provided between the rotor blade segments 8 interconnected in the circumferential direction of the rotor 6. FIG. 3 is a schematic plan top view of a set of adjacent stator blade segments 4a, 4b or rotor blade segments 8a, 8b applicable for use in forming a part of the refining surfaces 5, 9 of the stator 3 or the rotor 6 that are substantially similar to those of FIG. 2.

[0020] When the rotor blade segments 8a, 8b are fixed to the hub 7 of the rotor 6, there are longitudinal slit-shaped openings 14 between the rotor blade segments 8 adjacent to each other in the circumferential direction of the rotor 6. Through this opening 14, the fibrous material to be refined is supplied to the refining chamber 12 between the rotor 6 and the stator 3. Similarly, there are longitudinal slit-shaped openings 15 between the stator blade segments 4 adjacent to each other in the circumferential direction of the stator 3. Through this opening 15, the fibrous material that has already been refined in the refining chamber 12 is discharged from the refining chamber 12. This type of refiner configuration is called a side feed configuration or a side feed refiner.

[0021] Hereinafter, the blade segment structure according to the solution disclosed in this specification will be discussed in more detail with reference to FIGS. 4a, 4b, 5, and 6. FIG. 4a schematically shows a plan top view of blade segments 4a, 8a applicable for use on the side of the inner end 18 of the stator 3 or the rotor 6. FIG. 4b schematically shows a plan top view of blade segments 4b, 8b applicable for use on the side of the outer end 19 of the stator of the stator 3 or the rotor 6. Next, FIGS. 5 and 6 schematically disclose a plan view of another blade segment 4, 8 applicable for use in the stator 3 and / or the rotor 6 of a conical refiner, and the refining surfaces 5, 9 of the blade segments 4, 8 are omitted in FIGS. 5 and 6 for clarity. Considering the above FIG. 2, the blade segments 4, 8 in FIGS. 5 and 6 are intended to extend as a single uniform part from the inner end 18 of the stator 3 / rotor 6 to the outer end 19 of the stator 3 / rotor 6. Thus, the following description is applicable to each of the above-mentioned blade segments 4, 4a, 4b, 8, 8a, 8b, including the blade segments 4, 8 formed by interconnecting the inner blade segments 4a, 8a and their respective outer blade segments 4b, 8b.

[0022] The blade segments 4, 4a, 4b, 8, 8a, 8b include an inner edge portion 20 or a first edge portion 20 that is directed toward the inner end 18 of the refining elements 3, 6 having a smaller diameter. The blade segments further include an outer edge portion 21 or a second edge portion 21 that is directed toward the outer end 19 of the refining elements 3, 6 having a larger diameter. In the blade segments of conical and cylindrical refiners, the inner edge portion of the blade segment provides the axially inner end of the blade segment, and the outer edge portion of the blade segment provides the axially outer end of the blade segment, such that the direction from the axially inner end to the axially outer end provides the longitudinal axis of the blade segment. Thus, the outer edge portion 21 is substantially opposed to the inner edge portion 20 in the direction of the longitudinal axis of the blade segment. In FIG. 3, the longitudinal axis LA of the blade segment is schematically indicated by arrows at both the center line of the blade segment and the edge line of the blade segment, and these lines appear to have a common intersection outside FIG. 3 according to the representation of the conical segment in the plan view, but in the actual segment, each line or arrow is parallel in the view of FIG. 3. In other words, the arrow indicated by reference symbol LA and located on the center line of the blade segment points to the longitudinal axis of the blade segment at the center line of the blade segment, and the arrow indicated by reference symbol LA' and located on the edge line or edge of the blade segment points to the longitudinal axis of the blade segment at the edge of the blade segment. Thus, the longitudinal axis LA' is the longitudinal axis LA shown at the edge of the blade segment. Thus, both the longitudinal axis LA and the longitudinal axis LA' represent the same longitudinal axis of the blade segment, but are shown in this specification with different reference symbols for the purpose of the following description. Below the longitudinal axis LA at the edge line of the blade segment is also called the edge axis, indicated by reference symbol LA', and shown as a dashed line in FIG. 6. In FIGS. 4a, 4b, and 5, the longitudinal axis of the blade segment is schematically indicated by the center line of the blade segment and is thus indicated by reference symbol LA.

[0023] In a blade segment intended for a conical refiner, a line indicating the longitudinal axis LA of the blade segment actually extends along the conical surface of the blade segment and thus extends at an angle with respect to the shaft 11 of the conical refiner 1, but it should be noted that it can project with the shaft 11 so as to extend parallel to the shaft 11 of the refiner 1. In a blade segment intended for a conical refiner, next, a line indicating the longitudinal axis of the blade segment extending along the cylindrical surface of the blade segment extends substantially parallel to the shaft of the refiner. Further, in a blade segment intended for a disk refiner, next, a line indicating the longitudinal axis LA of the blade segment extends along the substantially flat surface of the blade segment in the radial direction of the blade segment, that is, in a disk-shaped blade segment, the longitudinal axis of the blade segment coincides with the radial direction of the blade segment.

[0024] The blade segment extends from the inner edge 20 of the blade segment to the outer edge 21 of the blade segment and further includes a first side edge 22 or a front side edge 22 that provides the side edge of the blade segment, which first meets the edge of the counter blade segment during the operation of the refiner. Therefore, in the rotor 6, it provides the side edge of the blade segment that is oriented in the intended rotational direction RD of the rotor 6, and in the stator 3, it provides the side edge of the blade segment that is oriented in the direction opposite to the intended rotational direction RD of the rotor 6.

[0025] The blade segment further has a second side edge 23 or a rear side edge 23 that is substantially opposite the first side edge 22 in a direction substantially orthogonal to the longitudinal axis LA of the blade segment, extends from the inner edge 20 of the blade segment to the outer edge 21 of the blade segment, and provides an edge of the counter blade segment and a side edge of the blade segment that is finally encountered during the operation of the refiner. Therefore, in the rotor 6, it provides a side edge of the blade segment that is directed in a direction opposite to the intended rotation direction RD of the rotor 6, and in the stator 3, it provides a side edge of the blade segment that is directed in a direction opposite to the intended rotation direction RD of the rotor 6, and in the stator 3, it provides a side edge that is directed towards the intended rotation direction RD of the rotor 6. The inner edge 20 and the outer edge 21, together with the first side edge 22 and the second side edge 23, define the perimeter of the blade segment 8.

[0026] The blade segment includes a body 24 having a front face 25 that is directed towards the refining chamber 12 of the refiner 1. The front face 25 of the blade segment body 24 is provided with blade bars 26 and blade grooves 27, which together provide the refining surfaces 5, 9 of the blade segment. The blade bars 26 are intended to defibrate and refine the material to be refined, and the blade grooves 27 are intended to convey the material to be refined forward along the refining surfaces 5, 9. The fastening holes 28 are intended to receive fastening means such as bolts and fix the blade segment directly to the support structure of the stator and the hub of the rotor, or via fixing elements such as rings 29, 30, etc.

[0027] At the innermost and outermost edge portions of the segment, there are extensions or shoulders 50, 51, 52, 53 on at least one of the side edges 22, 23 of the segment. The extensions or shoulders are intended to contact adjacent blade segments when assembled to provide a part of the refining surface of the refining element of the refiner. FIGS. 4a and 5 show the shoulders 50, 51 at the inner ends of the blade segments 4, 4a, 8, 8a, and FIGS. 4b and 5 show the shoulders 52, 53 at the outer ends of the blade segments 4, 4b, 8, 8b. The shoulders 50, 51, 52, 53 are at the corners of one segment as shown in FIG. 5, or at the corners of separate consecutive segments, i.e., the corners of the inner segments 4a, 8a, and the corners of the outer segments 4b, 8b, as can be seen in FIGS. 4a and 4b. Of course, shoulders 50, 51, 52, 53 can be provided at all corners of the segments 4, 8, and, similar to the embodiments of FIGS. 4a, 4b, the inner segments 4a, 8a can have shoulders 50, 51 at their inner edges 20 at both side edges or alternatively at each of their corners, and the outer segments 4b, 8b can each have shoulders 52, 53 at their outer edges 21 at both side edges or alternatively at each of their corners. The number of shoulders per side edge of one segment is from 2 to 10. Basically, these shoulders 50, 51, 52, 53 are the only or few parts where the segment makes lateral contact with adjacent segments.

[0028] In FIG. 6, edge axes LA’ are also drawn along the shoulder lines 50, 51, 52, 53, more specifically via the seam line between two adjacent segments, similar to the longitudinal axis LA of the segment, but in this specification, it extends parallel to the axial direction (i.e., the radial direction in the case of a disk refiner) presented at the edge of the blade segment in the manner already discussed above. The slit-shaped openings 14, 15 are formed in the first side edge 22 between the inner shoulder 50 and the outer shoulder 52 and the second side edge 23 between the inner shoulder 51 and the outer shoulder 53. The slit-shaped longitudinal openings 14, 15 can extend continuously from the innermost shoulder to the outermost shoulder without interruption other than those caused by a segment outer structure such as a fixed ring. Alternatively, the slit-shaped longitudinal openings 14, 15 may be discontinuous between the innermost shoulder and the outermost shoulder, as will be disclosed in more detail later, when the elbow is designed to contact the adjacent segment.

[0029] Referring to FIGS. 4a, 4b, and 5 and the blade segments 4, 8 therein, the first side edge 22 includes at least a substantially straight first long edge portion 31 in the direction from the inner edge 20 to the outer edge 21. The direction of the first long edge portion 31 deviates from the direction of the longitudinal axis LA of the blade segment, i.e., is arranged to deviate from the direction of the longitudinal axis LA of the blade segment, whereby the first long edge portion 31 is directed towards the central part or center line of the blade segment, and the center line of the blade segment is indicated by the longitudinal axis LA of the blade segment in FIGS. 4a, 4b, and 5.

[0030] Following the first long edge portion 31 is a first bent portion 32a that is bent in a direction away from the direction of the first long edge portion 31, i.e., in a direction opposite to the first long edge portion 31 with respect to the direction of the longitudinal axis LA (i.e., away from the central part or center line of the blade segment).

[0031] After the first bent portion 32a, a substantially straight or slightly curved short edge portion 32b follows. The direction of the short edge portion 32b is arranged to deviate from the direction of the longitudinal axis LA in a direction different from that of the first long edge portion 31, that is, in a direction opposite to that of the first long edge portion 31 with respect to the direction of the longitudinal axis LA (that is, away from the center or center line of the blade segment).

[0032] After the short edge portion 32b, a second bent portion 32c that is bent in a direction away from the direction of the first short edge portion 32b, that is, in a direction opposite to that of the short edge portion 32b with respect to the direction of the longitudinal axis LA (that is, toward the center or center line of the blade segment), follows. Thus, the second bent portion 32b is bent in a direction opposite to that of the first bent portion 32a with respect to the longitudinal axis LA.

[0033] The first bent portion 32a, the short edge portion 32b, and the second bent portion 32c provide an elbow 32 at the first side edge portion 22 of the blade segment. In other words, the elbow 32 at the first side edge portion 22 of the blade segment is composed of the first bent portion 32a, the short edge portion 32b following the first bent portion 32a, and the second bent portion 32c following the short edge portion 32b.

[0034] Next, after the second bent portion 32c or the elbow 32, a substantially straight second long edge portion 33 follows, and its direction deviates from the direction of the longitudinal axis LA of the blade segment in the same direction as that of the first long edge portion 31, that is, it is arranged to face the center or center line of the blade segment. In other words, after the second bent portion 32c, thus the elbow 32, a substantially straight second long edge portion 33 follows, and its direction is arranged to deviate from the direction of the longitudinal axis LA of the blade segment in the same direction as that of the first long edge portion 31 toward the blade segment. Thus, the second long edge portion 33 is arranged to deviate from the first long edge portion 31 in the same direction with respect to the direction of the longitudinal axis LA.

[0035] Furthermore, the second side edge 23 of the blade segments 4, 4a, 4b, 8, 8a, 8b includes a first long edge portion 41 that is at least substantially straight in a direction from the inner edge 20 to the outer edge 21. The direction of the first long edge portion 41 is offset from the direction of the longitudinal axis LA of the blade segment, i.e., arranged to be offset with respect to the direction of the longitudinal axis LA of the blade segment, whereby the long edge portion 41 is directed away from the center or center line of the blade segment.

[0036] Following the first long edge portion 41 is a first bend 42a that is bent in a direction away from the direction of the first long edge portion 41, i.e., bent in a direction opposite to the first long edge portion 41 with respect to the direction of the longitudinal axis LA (i.e., toward the center or center line of the blade segment).

[0037] Following the first bend 42a is a short edge portion 42b that is substantially straight or slightly curved. The direction of the short edge portion 42b is offset from the direction of the longitudinal axis LA in a direction different from that of the first long edge portion 41, i.e., arranged to be offset with respect to the direction of the longitudinal axis LA in a direction opposite to the first long edge portion 41 (i.e., toward the center line of the blade segment).

[0038] Following the short edge portion 42b is a second bend 42c that is bent in a direction away from the direction of the first short edge portion 42b, i.e., bent in a direction opposite to the short edge portion 42b with respect to the direction of the longitudinal axis LA (i.e., away from the center line of the blade segment). Thus, the second bend 42c is bent in a direction opposite to the first bend 42a with respect to the longitudinal axis LA.

[0039] The first bend 42a, the short edge portion 42b, and the second bend 42c provide an elbow 42 on the second side edge 23 of the blade segment. In other words, the elbow 42 at the second side edge 23 of the blade segment is composed of the first bend 42a, the short edge portion 42b following the first bend 42a, and the second bend 42c following the short edge portion 42b.

[0040] Next, following the second bent portion 42c or the elbow 42, there is a substantially straight second long edge portion 43, and its direction deviates from the direction of the longitudinal axis LA of the blade segment in the same direction as the first long edge portion 41, that is, it is arranged in a direction away from the center or the center line of the blade segment. In other words, following the second bent portion 42c, and thus the elbow 42, there is a substantially straight second long edge portion 43, and its direction is arranged so as to deviate from the direction of the longitudinal axis LA of the blade segment in the same direction as the first long edge portion 41. Thus, the second long edge portion 43 is arranged so as to deviate from the longitudinal axis LA in the same direction as the first long edge portion 41.

[0041] Considering further the blade segments 4, 8 in FIG. 5, the first side edge portions 22 of the blade segments 4, 8 in FIG. 5 further include another chamfered surface 34 following the second long edge portion 33. Thereby, following the second long edge portion 33, there is a third bent portion 34a, and the third bent portion 34a is bent in a direction away from the direction of the second long edge portion 33, that is, in a direction opposite to the direction of the second long edge portion 33 with respect to the longitudinal axis LA (that is, away from the center or the center line of the blade segment).

[0042] Following the third bent portion 34a, there is a substantially straight or slightly curved second short edge portion 34b. The direction of the second short edge portion 34b deviates from the direction of the longitudinal axis LA in a direction different from that of the second long edge portion 33, that is, in a direction opposite to the second long edge portion with respect to the longitudinal axis LA (that is, away from the center or the center line of the blade segment).

[0043] Following the second short edge portion 34b, there is a fourth bent portion 34c, and the fourth bent portion 34c is bent in a direction away from the direction of the second short edge portion 34b, that is, in a direction opposite to the second short edge portion 34b with respect to the longitudinal axis LA (that is, toward the center or the center line of the blade segment). Thus, the fourth bent portion 34c is bent in a direction opposite to the third bent portion 34a with respect to the longitudinal axis LA.

[0044] The third bent portion 34a, the second short edge portion 34b, and the fourth bent portion 34c provide the second elbow 34 to the first side edge portion 22 of the blade segment. In other words, the second elbow 34 at the first side edge portion 22 of the blade segment is composed of the third bent portion 34a, the second short edge portion 34b following the third bent portion 34a, and the fourth bent portion 34c following the short edge portion 34b.

[0045] Next, after the fourth bent portion 34c or the second elbow 34, a substantially straight third long edge portion 35 follows, and its direction deviates from the direction of the longitudinal axis LA of the blade segment in the same direction as the first long edge portion 31 and the second long edge portion 33, that is, it is arranged to face the center or the center line of the blade segment. In other words, after the fourth bent portion 34c and thus after the second elbow 34, a substantially straight third long edge portion 35 follows, and its direction is arranged to deviate from the direction of the longitudinal axis LA of the blade segment in the same direction as the first long edge portion 31 and the second long edge portion 33. Thus, the third long edge portion 35 is arranged to deviate from the direction of the longitudinal axis LA in the same direction as the first long edge portion 31 and the second long edge portion 33.

[0046] The ratio of the lengths of the short edge portions 32b, 34b to the lengths of the long edge portions 31, 33, 35 is about 1:2 to 1:20.

[0047] Similarly, the second side edge portion 23 of the blade segments 4, 8 in FIG. 5 includes another chamfered surface 44 following the second long edge portion 43. Thereby, after the second long edge portion 43, a third bent portion 44a follows, and the third bent portion 44a is bent in a direction away from the direction of the second long edge portion 43, that is, in a direction opposite to the second long edge portion with respect to the direction of the longitudinal axis LA (that is, toward the center or the center line of the blade segment).

[0048] After the third bent portion 44a, a second short edge portion 44b that is substantially linear or slightly curved follows. The direction of the second short edge portion 44b is arranged to deviate from the direction of the longitudinal axis LA in a direction different from that of the second long edge portion 43, that is, in a direction opposite to the second long edge portion with respect to the direction of the longitudinal axis LA (that is, toward the center or the center line of the blade segment).

[0049] After the second short edge portion 44b, a fourth bent portion 44c follows, and the fourth bent portion 44c is bent in a direction away from the direction of the second short edge portion 44b, that is, in a direction opposite to the second short edge portion 44b with respect to the direction of the longitudinal axis LA (that is, away from the center or the center line of the blade segment). Thus, the fourth bent portion 44c is bent in a direction opposite to the third bent portion 44a with respect to the longitudinal axis LA.

[0050] The third bent portion 44a, the second short edge portion 44b, and the fourth bent portion 44c provide a second elbow 44 on the second side edge portion 23 of the blade segment. In other words, the second elbow 44 at the second side edge portion 23 of the blade segment is composed of the third bent portion 44a, the second short edge portion 44b following the third bent portion 44a, and the fourth bent portion 44c following the second short edge portion 44b.

[0051] Next, after the fourth bent portion 44c or the second elbow 44, a substantially linear third long edge portion 45 follows, and its direction is arranged to deviate from the direction of the longitudinal axis LA of the blade segment in the same direction as the first long edge portion 41 and the second long edge portion 43, that is, to deviate in a direction away from the center or the center line of the blade segment. In other words, after the fourth bent portion 44c, thus after the second elbow 44, a substantially linear third long edge portion 45 follows, and its direction is arranged to deviate from the direction of the longitudinal axis LA of the blade segment in the same direction as the first long edge portion 41 and the second long edge portion 43. Thus, the third long edge portion 45 is arranged to deviate from the direction of the longitudinal axis LA in the same direction as the first long edge portion 41 and the second long edge portion 43.

[0052] The ratio of the lengths of the short edge portions 42b and 44b to the lengths of the long edge portions 41, 43, and 45 is about 1:2 to 1:20.

[0053] In the embodiments of the blade segments of FIGS. 4a, 4b, and 5, both side edge portions 22, 23 of the blade segment are arranged so as to deviate from the direction of the longitudinal axis LA of the blade segments 4, 4a, 4b, 8, 8a, 8b, and include at least two edge portions 31, 33, 35, 41, 43, 45 that are connected by elbows 32, 34 between each two edge portions.

[0054] In the embodiments of the blade segments of FIGS. 4a, 4b, and 5, the configuration of the side edge portions 22, 23 is also arranged so as to deviate from the mirror image with respect to the longitudinal axis LA of the blade segment. In other words, the side edge portions of the blade segments of FIGS. 4a, 4b, and 5 are not mirror images of each other with respect to the longitudinal axis LA of the blade segments 4, 4a, 4b, 8, 8a, 8b on the center line of the blade segments 4, 4a, 4b, 8, 8a, 8b.

[0055] Generally, according to the disclosed solution, at least one side edge portion 22, 23 of the blade segments 4, 4a, 4b, 8, 8a, 8b includes at least two edge portions 31, 33, 35, 41, 43, 43, 45, and their directions are arranged so as to deviate from the direction of the longitudinal axis LA of the blade segments 4, 4a, 4b, 8, 8a, 8b, and the at least two edge portions are connected by elbows 32, 34 between each two edge portions.

[0056] According to a further embodiment, the directions of the edge portions 31, 33, 35, 41, 43, 45 at the specific side edges 22, 23 are arranged to deviate in the same direction from the direction of the longitudinal axis LA, and the elbows 32, 34, 42, 44 are bent away from the edge portions 31, 33, 35, 41, 43, 45 so as to deviate in a direction different from that of the edge portions 31, 33, 35, 41, 43, 45 with respect to the direction of the longitudinal axis LA of the blade segment.

[0057] According to one embodiment of the blade segment, as schematically shown on the side of the first side edge 22 of the blade segments 4, 8 in FIG. 6, the reach of the elbows 32, 34, or more specifically, the length of the short edge portions 32b, 34b, can be configured not to substantially exceed the edge axis LA', whereby continuous slit-like openings 14, 15 can be provided between adjacent segments 4, 8. In other words, in this embodiment, the elbows 32, 34 are arranged at the first side edge 22 of the blade segments 4, 8 so as not to exceed the longitudinal axis LA' of the blade segments 4, 8.

[0058] According to one embodiment of the blade segment, as schematically shown on the side of the second side edge 23 of the blade segments 4, 8 in FIG. 6, the reach of the elbows 42, 44 can be configured such that the elbows extend to the edge axis LA' like the elbow 44 or exceed the edge axis LA' like the elbow 42. In other words, in this embodiment, the elbows 42, 44 extend to the longitudinal axis LA' of the blade segments 4, 8 at the second side edge 22 of the blade segments 4, 8 or may even exceed the longitudinal axis LA' of the blade segments 4, 8 at the second side edge 22 of the blade segments 4, 8. When the opposing side edges 22, 23 are not parallel, the elbows may even exceed the edge axis LA' to such an extent as to allow contact with adjacent segments, whereby discontinuous slit-like openings 14, 15 can be provided between adjacent segments 4, 8.

[0059] The disclosed configuration of the side edge portion of the blade segment provides a gentle zigzag shape that deviates from the direction of the longitudinal axis of the blade segment. When the configuration of the opposite side edge portion is selected to cooperate with the configuration of the first-mentioned side edge portion, the configuration of the opposite side edge portion provides a longitudinal slit-shaped opening, i.e., a flow path, between adjacent blade segments, and the flow path supplies the fibrous material to be refined into the refining chamber between the stator and the rotor and discharges the already refined fibrous material from the refining chamber. Therefore, this slit-shaped opening having a stepped or stepped opening configuration has a center line in a direction deviating from the axial direction of the blade segment at least in most of the extension of the opening. This results in the angle of incidence between the opening of the rotor and the opening of the stator changing in the axial direction of the refiner, or in the longitudinal axis and the edge axis of the blade segment, and moving the point of incidence between the opening of the rotor and the opening of the stator away from the axial direction of the refiner or the longitudinal axis of the blade segment. Next, this has the effect of being able to reduce the fluctuations in the possible flow pulsations, and thus the vibrations that appear during the operation of the refiner.

[0060] According to one embodiment, the slit-shaped opening has a width between 10 mm and 25 mm.

[0061] According to one embodiment, the edge portions that are on the same side edges 22, 23 of the blade segment and are arranged to deviate in the same direction from the direction of the longitudinal axis LA of the blade segment are substantially parallel. This effect is that an opening with a substantially constant width is easily realized between adjacent blade segments.

[0062] According to one embodiment, each side edge portion of the blade segment includes at least one elbow. This effect is that both side edge portions of the blade segment have a kind of gentle zigzag shape, thereby preventing most of the side edge portion from following the longitudinal axis of the blade segment, thereby preventing the formation of an opening that may cause the tendency of the refiner to vibrate during operation.

[0063] According to one embodiment, the elbows of the opposing side edges are at the same normal level with respect to the longitudinal axis LA of the blade segment, and the normal to the longitudinal axis LA of the blade segment is indicated by a dashed line with reference symbol IN in FIG. 5 and is schematically shown. This has the effect of providing an opening having a substantially constant width along the longitudinal extension of the opening.

[0064] According to one embodiment, the number of elbows at each side edge 22, 23 is 1 to 10, preferably 2 to 6, or 2 to 7, or 2 to 8. When the number of elbows at the side edge is appropriate, deviation in the extension direction of the opening from the longitudinal axis of the blade segment can be ensured. If the zigzag shape of the side edge of the blade segment is too dense, a permanent reciprocating type flow path for the pulp may occur, which is ultimately not much different from a design that may not be vibrationally desirable.

[0065] According to one embodiment, the deflection angle (deviated angle) of the elbow from the longitudinal axis LA of the blade segment is about 10 to 90 degrees, preferably 10 to 60 degrees, more preferably 10 to 50 degrees.

[0066] According to one embodiment, the extension direction of the elbow is substantially parallel to the extension direction of the blade bar. In other words, the elbows are arranged to form an angle substantially parallel to the blade bar angle applied to the blade segment.

[0067] According to one embodiment, the configurations of the side edges 22, 23 are arranged to deviate from the mirror image with respect to the longitudinal axis of the blade segment. In other words, the side edges of the blade segment are not mirror images of each other with respect to the longitudinal axis LA of the blade segment.

[0068] As technology progresses, it will be apparent to those skilled in the art that the concepts of the present invention can be implemented in various ways. The present invention and its embodiments are not limited to the above examples and can be modified within the scope of the claims.

Claims

1. A blade segment (4, 8) for a refiner (1) for refining fibrous material, the blade segment (4, 8) comprising: a first edge portion (20) in the direction of the longitudinal axis (LA) of the blade segment (4, 4a, 4b, 8, 8a, 8b) and a second edge portion (21) on the opposite side of the first edge portion; a first side edge portion (22) and a second side edge portion (23) on the opposite side of the first side edge portion (22), the first side edge portion (22) and the second side edge portion (23) extending between the first edge portion (20) and the second edge portion (21); a refining surface (5, 9) on the front surface (25) of the blade segment (4, 8) including blade bars (26) and blade grooves (27) between these blade bars; at least one side edge portion (22, 23) is arranged to deviate from the direction of the longitudinal axis (LA) of the blade segment (4, 4a, 4b, 8, 8a, 8b) and includes at least two long edge portions (31, 33, 35, 41, 43, 45) connected by elbows (32, 34, 42, 44) between each two edge portions (31, 33, 35, 41, 43, 45), the elbows (32, 34, 42, 44) comprising a first bend (32a, 34a, 42a, 44a), a short edge portion (32b, 34b, 42b, 44b) following the first bend (32a, 34a, 42a, 44a), and a second bend (32c, 34c, 42c, 44c) following the short edge portion (32b, 34b, 42b, 44b); the long edge portions (31, 33, 35, 41, 43, 45) are arranged to deviate in the same direction with respect to the direction of the longitudinal axis (LA), and the elbows (32, 34, 42, 44) are bent away from the long edge portions (31, 33, 35, 41, 43, 45) in a direction different from the long edge portions (31, 33, 35, 41, 43, 45) with respect to the direction of the longitudinal axis (LA); Blade segment.

2. The side edges (22, 23) are arranged so as to deviate from the direction of the longitudinal axis (LA) of the blade segment (4, 4a, 4b, 8, 8a, 8b) and are connected by the elbows (32, 34, 42, 44) between each two edge portions (31, 33, 35, 41, 43, 45). The blade segment according to claim 1, comprising at least two long edge portions (31, 33, 35, 41, 43, 45).

3. The long edge portions (31, 33, 35, 41, 43, 45) that are on the same side edge (22, 23) and are arranged so as to deviate in the same direction from the direction of the longitudinal axis (LA) are substantially parallel. The blade segment according to claim 1 or 2.

4. The side edges (22, 23) are arranged so as to deviate from the direction of the longitudinal axis (LA) of the blade segment (4, 4a, 4b, 8, 8a, 8b) at least in the direction from the inner edge (20) to the outer edge (21). It includes a substantially straight first long edge portion (31, 41), a first bending portion (32a, 42a) that follows the first long edge portion (31, 41) and is bent in a direction away from the direction of the first long edge portion (31, 41), and a first short edge portion (32b, 42b) that follows the first bending portion (32a, 42a) and is arranged so as to deviate in a direction different from the first long edge portion (31, 41) from the direction of the longitudinal axis (LA) of the blade segment (4, 4a, 4b, 8, 8a, 8b), and a second bending portion (32c, 42c) that follows the first short edge portion (32b, 42b) and is bent in a direction away from the direction of the first short edge portion (32b, 42b), and a second long edge portion (33, 43) that follows the second bending portion (32c, 42c) and is arranged so as to deviate in the same direction as the first long edge portion (31, 41) from the direction of the longitudinal axis (LA) of the blade segment (4, 4a, 4b, 8, 8a, 8b). The first bending portion (32a, 42a), the short edge portion (32b, 42b), and the second bending portion (32c, 42c) provide the elbow (32) to the side edge (22, 23) of the blade segment (4, 4a, 4b, 8, 8a, 8b). The blade segment according to any one of claims 1 to 3.

5. The blade segment according to any one of claims 2 to 4, wherein each side edge portion (22, 23) includes at least one elbow (32, 34, 42, 44).

6. The blade segment according to any one of claims 2 to 5, wherein the elbows (32, 34, 42, 44) in the opposing side edge portions (22, 23) are at the same normal (N) level with respect to the longitudinal axis (LA).

7. The blade segment according to any one of claims 2 to 6, wherein the number of elbows (32, 34, 42, 44) in each side edge portion (22, 23) is from 1 to 10.

8. The blade segment according to any one of claims 1 to 7, wherein the deflection angle of the elbows (32, 34, 42, 44) with respect to the longitudinal axis (LA) is from 10 to 90 degrees.

9. The blade segment according to any one of claims 1 to 8, wherein the extending direction of the elbows (32, 34, 42, 44) is substantially parallel to the extending direction of the blade bar (26).

10. The blade segment according to any one of claims 1 to 9, wherein the side edge portions (22, 23) are not mirror images of each other with respect to the longitudinal axis (LA) of the blade segment (4, 4a, 4b, 8, 8a, 8b).

11. The blade segment according to any one of claims 1 to 10, wherein the elbow (42) is arranged so as to extend beyond the edge axis (LA') of the blade segment (4, 4a, 4b, 8, 8a, 8b), and the edge axis (LA') of the blade segment (4, 4a, 4b, 8, 8a, 8b) corresponds to the longitudinal axis (LA) of the blade segment (4, 4a, 4b, 8, 8a, 8b) at the edge portion (23) of the blade segment (4, 4a, 4b, 8, 8a, 8b).

12. At least one end of the blade segment (4, 4a, 4b, 8, 8a, 8b) is at both corners of the blade segment (4, 4a, 4b, 8, 8a, 8b), and the shoulders (50, 51, 52, 53) are for the purpose of contacting an adjacent blade segment (4, 4a, 4b, 8, 8a, 8b) when assembled to provide a part of the refining surface (5, 9) of the refining element (3, 6) of the refiner (1). The blade segment according to any one of claims 1 to 11.

13. The blade segment according to any one of claims 1 to 12, wherein the ratio of the length of the short edge portion (32b, 34b, 42b, 44b) to the length of the long edge portion (31, 33, 35, 41, 43, 45) is 1:2 to 1:

20.

14. A refiner for refining fibrous materials, comprising at least one blade segment (4, 4a, 4b, 8, 8a, 8b) according to any one of claims 1 to 13.

15. The refiner according to claim 14, wherein in the refining element (3, 6) of the refiner (1), there are continuous slit-shaped openings (14, 15) between adjacent blade segments (4, 4a, 4b, 8, 8a, 8b).

16. The refiner according to claim 14, wherein in the refining element (3, 6) of the refiner (1), there are discontinuous slit-shaped openings (14, 15) between adjacent blade segments (4, 4a, 4b, 8, 8a, 8b).

Images