Blade segments for fine grinding machines

Abstract

A blade segment (4, 8) of a refiner (1) for refining fibrous material. The blade segment (4, 8) comprises: a first end edge (20) and a second end edge (21), the second end edge being opposite to the first end edge in the direction of the longitudinal axis (LA) of the blade segment (4, 4a, 4b, 8, 8a, 8b); a first side edge (22) and a second side edge (23), the second side edge being opposite to the first side edge, the first side edge and the second side edge extending between the first end edge and the second end edge; and a refining surface (5, 9) comprising teeth (26) and grooves (27) located between the teeth on a front surface (25) of the blade segment (4, 8). At least one side edge (22, 23) comprises at least two edge portions (31, 33, 35, 41, 43, 45), which are arranged to deviate from the direction of the longitudinal axis (LA) of the blade segment (4, 4a, 4b, 8, 8a, 8b) and are connected by an elbow portion (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, and in particular to a blade segment (refining sheet) of a refiner for refining fibrous materials. Background Art

[0002] A refiner for refining fibrous material, such as a refiner for making mechanical pulp or a refiner used in any low-consistency refining, usually comprises two refining elements which are opposite to each other and which rotate relative to each other (i.e. one or both of them rotate). The refining element comprises a refining surface provided with teeth for defibering and refining the material to be refined and with grooves between the teeth for conveying the material to be refined forward along the refining surface. The refining surface of the refining element is usually formed by several blade segments fixed to the body of the respective refining element, each blade segment comprising a respective refining surface formed by teeth and grooves between the teeth. Thus, the complete refining surface of the refining element is formed by the refining surfaces of several blade segments fixed closely to each other in the refining element. EP publication number 3401439B1 discloses a blade segment suitable for use in a refiner for refining fibrous material. Summary of the invention

[0003] It is an object of the present invention to provide a new blade segment for a refiner for refining fibrous material, and a new refiner for refining fibrous material.

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

[0005] The invention is based on the idea of ​​configuring at least one side edge of a blade segment to provide a shape which deviates from a direction of a longitudinal axis of the blade segment.

[0006] When the shape of at least one side edge of a blade segment is arranged to have a shape that deviates from the direction of the longitudinal axis of the blade segment, and when the configuration of the opposing side edge is selected to cooperate with the configuration of the first-mentioned side edge, it provides a longitudinal slit-like opening (and thus a flow path) between adjacent blade segments for supplying fiber material to be refined into the refining chamber between the stator and the rotor and for discharging the refined fiber material from the refining chamber. The slit-like opening thus has a center line, the direction of which deviates from the direction of the longitudinal axis of the blade segment, at least over a large part of the extension of the opening. This has the effect that the angle of incidence between the opening in the rotor and the opening in the stator varies in the axial direction of the refiner, resulting in the point of incidence between the opening in the rotor and the opening in the stator moving away from the axial direction of the refiner. This in turn has the effect that possible flow variations that occur in the operation of the prior art refiner can be reduced.

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

[0008] The present invention will be described in more detail below by means of preferred embodiments with reference to the accompanying drawings, in which:

[0009] Figure 1 is a schematic overall side view of a conical refiner shown in cross section;

[0010] Figure 2 Is applicable to Figure 1 A schematic oblique side view of a stator and a rotor in a refiner;

[0011] Figure 3 is a schematic plan view of a set of stator / rotor blade segments;

[0012] Figure 4a and Figure 4b is a schematic top plan view of a blade segment according to the solution; and

[0013] Figure 5 and Figure 6 A schematic top plan view of another blade segment according to this solution is shown.

[0014] For the sake of clarity, the accompanying drawings show some embodiments of the present invention in a simplified manner. In the accompanying drawings, similar reference numerals represent similar elements. DETAILED DESCRIPTION

[0015] Figure 1 is a schematic overall side view of the overall structure of a refiner 1 shown in cross section, which can be used for refining fibrous material, such as lignocellulose-containing wood or other fibrous material suitable for making paper or paperboard. Figure 1 The refiner 1 shown is of a conical type, but disc refiners, cone-disc refiners and cylindrical refiners may also be used as examples here. Typically, a refiner comprises: at least two substantially oppositely positioned refining elements, at least one of which is rotatable; and a refining chamber formed between each two substantially oppositely positioned refining elements. In the following, a refiner with only one rotatable refining element is described.

[0016] Figure 1The refiner 1 comprises a frame 2 and a stationary refining element 3 supported on the frame 2, i.e. a stator 3. The stator 3 comprises two or more stator blade segments 4, each of which comprises teeth and grooves located between the teeth. The teeth and grooves in each stator blade segment 4 form a refining surface 5 of the corresponding blade segment 4, so that 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 by the refining surfaces 5 of the necessary number of blade segments 4 fixed closely to each other in the stator 3, thereby providing a complete refining surface 5 extending over the entire circumference of the stator 3. For the sake of clarity, both the refining surface of each individual stator blade segment 4 and the complete refining surface of the stator 3 are denoted herein by the same reference numeral 5.

[0017] The refiner 1 further comprises a rotatable refining element 6 of the refiner 1, i.e. a rotor 6. The rotor 6 comprises a hub 7. The rotor 6 further comprises two or more rotor blade segments 8 supported to the hub 7, each rotor blade segment 8 comprising teeth and grooves located between the teeth. The teeth and grooves in 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 by the refining surfaces 9 of the necessary number of blade segments 8 fixed closely to each other in the rotor 6, thereby providing a complete refining surface 9 extending over the entire circumference of the rotor 6. For the sake of clarity, the refining surface of each single rotor blade segment 8 and the complete refining surface of the rotor 6 are both denoted herein by the same reference numeral 9.

[0018] The hub 7 of the rotor 6 is connected to the drive motor 10 via a shaft 11 so that the rotor 6 can rotate relative to the stator 3 in the direction of arrow RD, for example, which thus indicates the intended rotation direction RD of the rotor 6 .

[0019] The refiner 1 may also include a loading device, for the sake of clarity, Figure 1 The loading device is not shown in the drawing. The loading device can be used to move the rotor 6 attached to the shaft 11 back and forth (as schematically shown by arrow A) in order to adjust the size of the refining gap 12 between the stator 3 and the rotor 6, i.e. the refining chamber 12, in which the fiber material is actually refined.

[0020] The fiber material to be refined is fed into the refiner 1 via a feed channel 13 in a manner indicated by arrows F. In one embodiment, most of the fiber material fed into the refiner 1 passes through openings 14 (i.e., flow paths) in the refining surface 9 of the rotor 6 into the refining chamber 12 in a manner indicated schematically by arrows P, where the fiber material is refined. Furthermore, most of the already refined fiber material is discharged again through openings 15 (i.e., flow paths) in the refining surface 5 of the stator 3 into the intermediate space 16 between the frame 2 and the stator 3 of the refiner 1, where the refined material is removed from the refiner 1 via a discharge channel 17, as indicated schematically by arrows D.

[0021] because Figure 1 The space between the rotor 6 and the frame 2 of the refiner 1 is not completely closed, so some fiber material to be fed into the refiner 1 can be transferred from the right end of the refiner chamber 12 (i.e., from the first end 18 or the inner end 18 of the refiner 1 having a smaller diameter) into the refiner chamber 12, as shown in FIG. Figure 1 Accordingly, some of the refined materials may also leave the refiner 12 from the left end of the refiner 12 (ie, from the second end 19 or the outer end 19 of the refiner 1 having a larger diameter), as shown in FIG. Figure 1 As shown, a connection is provided from this left end to the intermediate space 16 .

[0022] exist Figure 1 In the embodiment of the refiner 1 of FIG. 1 , only one feed channel 13 is provided and is arranged at a first end 18 of the refiner 1 having a smaller diameter. A practical embodiment of the refiner may also comprise a second feed channel arranged at a second end 19 of the refiner 1 having a larger diameter, whereby the discharge channel 17 of the refiner 1 may be arranged, for example, somewhere between the first end 18 and the second end 19 of the refiner 1. In the following, reference numeral 18 and the term first end 18 or the term inner end 18 may denote both a first end 18 or inner end 18 of the refiner 1 having a smaller diameter and a first end 18 or inner end 18 of a refining element 3, 6 or a refining chamber 12 having a smaller diameter. Correspondingly, reference numeral 19 and the term second end 19 or the term outer end 19 may denote both a second end 19 or outer end 19 of the refiner 1 having a larger diameter and a second end 19 or outer end 19 of a refining element 3, 6 or a refining chamber 12 having a larger diameter.

[0023] It should be emphasized that, in addition to being applicable to the conical refiners disclosed above, the blade segments of the solutions described herein can also be applied to other types of conical refiners. In addition to being applicable to conical refiners, the blade segments of the solutions described herein can also be applied to cylindrical refiners and disc refiners, as well as refiners comprising both conical and disc portions.

[0024] Figure 2 is a schematic oblique side view of a stator 3 and a rotor 6 of a conical refiner, the stator 3 being shown in cross section. In the circumferential direction of the stator 3, there are a plurality of adjacent inner blade segments 4a on the side of the inner end 18 of the stator 3, and a corresponding number of adjacent outer blade segments 4b on the side of the outer end 19 of the stator 3, the inner segments 4a and the outer segments 4b together providing a blade segment 4. At corresponding circumferential positions of the stator 3, each inner blade segment 4a is interconnected with a corresponding outer blade segment 4b to provide a blade segment 4, at which a substantially continuous refining surface 5 is provided between the inner end 18 and the outer end 19 of the stator 3 at the corresponding inner stator blade segments 4a and the outer stator blade segments 4b of the blade segment 4. The side edges of the stator blade segments 4a, 4b are implemented so that a slit-like opening 15 forming a flow path is provided between the interconnected stator blade segments 4 in the circumferential direction of the stator 3.

[0025] Similarly, along the circumferential direction of the rotor 6, there are a plurality of adjacent inner blade segments 8a on the side of the inner end 18 of the rotor 6, and a corresponding number of adjacent outer blade segments 8b on the side of the outer end 19 of the rotor 6, which inner blade segments 8a and outer blade segments 8b together provide a blade segment 8. At corresponding circumferential positions of the rotor 6, each inner blade segment 8a is interconnected with the corresponding outer blade segment 8b to provide a blade segment 8, and a substantially continuous fine grinding surface 9 is provided between the inner end 18 and the outer end 19 of the rotor 6 at the corresponding inner stator blade segments 8a and the outer stator blade segments 8b of the blade segment 8. The side edges of the rotor blade segments 8a, 8b are implemented so that a slit-like opening 14 forming a flow path is provided between the interconnected rotor blade segments 8 along the circumferential direction of the rotor 6. Figure 3 is a schematic top plan view of a group of adjacent interconnected stator blade segments 4a, 4b or a group of adjacent interconnected rotor blade segments 8a, 8b, which are suitable for forming a stator blade segment with Figure 2 A portion of a refined surface 5, 9 of a stator 3 or rotor 6 of a substantially similar stator or rotor.

[0026] When the rotor blade segments 8a, 8b are fastened to the hub 7 of the rotor 6, there will thus be longitudinal slit-like openings 14 between adjacent rotor blade segments 8 in the circumferential direction of the rotor 6, through which openings 14 the fibrous material to be refined is supplied into the refining chamber 12 between the rotor 6 and the stator 3. Similarly, there will be longitudinal slit-like openings 15 between adjacent stator blade segments 4 in the circumferential direction of the stator 3, through which openings 15 the fibrous material which has been refined in the refining chamber 12 is discharged from the refining chamber 12. Such a refiner configuration is referred to as a side-feed configuration or a side-feed refiner.

[0027] In the following, based on Figure 4a , Figure 4b , Figure 5 and Figure 6 Considering in more detail the blade segment structure according to the solution described herein, wherein: Figure 4a Schematically shows a plan view of a blade segment 4a, 8a suitable for use on the side of the inner end 18 of the stator 3 or rotor 6, and Figure 4b A blade segment 4b, 8b suitable for use on the side of the outer end 19 of the stator 3 or rotor 6 is schematically shown in a top plan view. Figure 5 and Figure 6 A further blade segment 4, 8 suitable for use in a stator 3 and / or a rotor 6 of a conical refiner is schematically disclosed in a top plan view, which is not shown for the sake of clarity. Figure 5 and Figure 6 The finely ground surfaces 5 and 9 of the blade segments 4 and 8 are omitted. Figure 2 hour, Figure 5 and Figure 6 The blade segments 4, 8 are intended to extend as a single unified piece from the inner end 18 of the stator 3 / rotor 6 to the outer end 19 of the stator 3 / rotor 6. The following description therefore applies to each blade segment 4, 4a, 4b, 8, 8a, 8b mentioned above, including blade segments 4, 8 formed by interconnecting inner blade segments 4a, 8a and corresponding outer blade segments 4b, 8b.

[0028] The blade segment 4, 4a, 4b, 8, 8a, 8b comprises an inner end edge 20 or a first end edge 20 which is oriented towards the inner end 18 of the refining element 3, 6 having a smaller diameter. The blade segment further comprises an outer end edge 21 or a second end edge 21 which is oriented towards the outer end 19 of the refining element 3, 6 having a larger diameter. In blade segments for conical refiners and cylindrical refiners, the inner end edge of the blade segment serves as the axial inner end of the blade segment and the outer end edge of the blade segment serves as the axial outer end of the blade segment, the direction from the axial inner end towards the axial outer end thus providing the longitudinal axis of the blade segment. Therefore, in the direction of the longitudinal axis of the blade segment, the outer end edge 21 is substantially opposite to the inner end edge 20. Figure 3 In the diagram, the longitudinal axis LA of the blade segment is schematically indicated by an arrow at the center line of the blade segment and an arrow at the edge line of the blade segment, the center line and the edge line being in the plane view in response to the representation of the conical segment. Figure 3 The exterior of the segments appear to have a common intersection, but in the actual segments, the corresponding lines or arrows are Figure 3In other words, the arrow indicated by reference numeral LA and located at the center line of the blade segment refers to the longitudinal axis of the blade segment at the center line of the blade segment, while the arrow indicated by reference numeral LA' and located at the edge line or edge of the blade segment refers to the longitudinal axis of the blade segment at the edge of the blade segment. Therefore, the longitudinal axis LA' is the longitudinal axis LA shown at the edge of the blade segment. Therefore, the longitudinal axis LA and the longitudinal axis LA' both refer to the same longitudinal axis of the blade segment, but are indicated by different reference numerals in this document for the following description. Hereinafter, the longitudinal axis LA at the edge line of the blade segment is also referred to as the edge axis and is indicated by reference numeral LA' and located at the edge line or edge of the blade segment. Figure 6 It is shown by a dotted line. Figure 4a , Figure 4b and Figure 5 In the drawings, the longitudinal axis of the blade segment is schematically indicated at the center line of the blade segment and is therefore denoted by reference numeral LA.

[0029] It should be noted that in a blade segment for a conical refiner, the line representing the longitudinal axis LA of the blade segment actually extends along the conical surface of the blade segment and therefore extends at an angle relative to the axis 11 of the conical refiner 1, but can be projected at the axis 11 so as to extend parallel to the axis 11 of the refiner 1. Whereas in a blade segment for a cylindrical refiner, the line representing the longitudinal axis LA of the blade segment extending along the cylindrical surface of the blade segment extends substantially parallel to the axis of the refiner. Furthermore, in a blade segment for a disc refiner, the line representing the longitudinal axis LA of the blade segment extends in the radial direction of the blade segment along the substantially flat surface of the blade segment, i.e. in a disc-shaped blade segment, the longitudinal axis of the blade segment coincides with the radial direction of the blade segment.

[0030] The blade segment further comprises a first side edge 22 or a front side edge 22 which extends from the inner end edge 20 of the blade segment as far as the outer end edge 21 of the blade segment and is the side edge of the blade segment which first meets the edge of the opposing blade segment during operation of the refiner. Thus, in the rotor 6, the side edge of the blade segment is made to point in the intended direction of rotation RD of the rotor 6, while in the stator 3, the side edge of the blade segment is made to point in the direction opposite to the intended direction of rotation RD of the rotor 6.

[0031] The blade segment further comprises a second side edge 23 or a rear side edge 23 which is substantially opposite to the first side edge 22 in a direction substantially perpendicular to the longitudinal axis LA of the blade segment and which extends from the inner end edge 20 of the blade segment up to the outer end edge 21 of the blade segment and which is the side edge of the blade segment which last meets the edge of the opposing blade segment during operation of the refiner. Thus, in the rotor 6, the side edge of the blade segment is made to point in a direction opposite to the intended direction of rotation RD of the rotor 6 and in the stator 3, the side edge is made to point in the intended direction of rotation RD of the rotor 6. The inner end edge 20 and the outer end edge 21 together with the first side edge 22 and the second side edge 23 define the periphery of the blade segment 8.

[0032] The blade segment comprises a body 24 having a front surface 25 pointing towards the refining chamber 12 of the refiner 1. The front surface 25 of the blade segment body 24 is provided with teeth 26 and grooves 27 which together provide the refining surfaces 5, 9 of the blade segment. The teeth 26 serve for defibering and refining the material to be refined and the grooves 27 serve for conveying the material to be refined forward along the refining surfaces 5, 9. The fastening holes 28 serve for accommodating fastening means, such as bolts, for fastening the blade segment to the support structure of the stator and the hub of the rotor directly or via fastening elements, such as rings 29, 30 etc.

[0033] At the innermost and outermost end edges of the segments, there are extensions or shoulders 50, 51, 52, 53 on at least one side edge 22, 23 of the segments. The extensions or shoulders are intended to make contact with adjacent blade segments during assembly, thereby providing a part of the refining surface of a refining element of a refiner. Figure 4a and Figure 5 The shoulders 50, 51 at the inner ends of the blade segments 4, 4a, 8, 8a are shown, while Figure 4b and Figure 5 Shown are shoulders 52, 53 at the outer ends of the blade segments 4, 4b, 8, 8b. Figure 5 As shown in FIG, shoulders 50, 51, 52, 53 may be located at the corners of one segment, or at the corners of separate consecutive segments, i.e., as shown in FIG. Figure 4a and Figure 4b As shown, it is located on the (multiple) corners of the inner segments 4a, 8a and on the (multiple) corners of the outer segments 4b, 8b. Naturally, all corners of the segments 4, 8 can be provided with shoulders 50, 51, 52, 53 and with Figure 4a , Figure 4bSimilarly to the embodiment of the embodiment of the present invention, the inner segments 4a, 8a may have shoulders 50, 51 on both side edges at the inner edge 20 or alternatively on each of its corners, and the outer segments 4b, 8b may have shoulders 52, 53 on both side edges at the outer edge 21 or alternatively on each of its corners, respectively. The number of shoulders per side edge of a segment is 2 to 10. Basically, these shoulders 50, 51, 52, 53 are the only or few parts of a segment that are in lateral contact with its adjacent segments.

[0034] exist Figure 6 In the embodiment of the present invention, there is also an edge axis LA' drawn along the shoulder line 50, 51, 52, 53, more specifically extending via the seam line between two adjacent segments and parallel to the axial direction of the refiner (or radial direction in the case of a disc refiner), just like the longitudinal axis LA of the segment, but here present at the edge of the blade segment in the manner already discussed above. The slit-like openings 14, 15 are formed on the first side edge 22 between the inner shoulder 50 and the outer shoulder 52 and on the second side edge 23 between the inner shoulder 51 and the outer shoulder 53. The slit-like longitudinal openings 14, 15 can extend continuously from the innermost shoulder to the outermost shoulder without further interruptions except for the interruptions caused by the segment outer structure (such as a fastening ring). Alternatively, the slit-like longitudinal openings 14, 15 can be discontinuous between the innermost shoulder and the outermost shoulder when an elbow is designed for contact with the adjacent segment, as disclosed in more detail later.

[0035] Reference Figure 4a , Figure 4b and Figure 5 And the blade segments 4, 8 therein, in the direction from the inner end edge 20 towards the outer end edge 21, the first side edge 22 comprises an at least substantially straight first long edge portion 31. The direction of the first long edge portion 31 is arranged to deviate from the direction of the longitudinal axis LA of the blade segment, i.e., to deviate relative to the direction of the longitudinal axis LA of the blade segment, so that the first long edge portion 31 points to the center portion or center line of the blade segment, the center line of the blade segment being at Figure 4a , Figure 4b and Figure 5 The longitudinal axis LA of the blade segment is represented in the figure.

[0036] The first long edge portion 31 is followed by a first bend 32a which turns away from the first long edge portion 31 , i.e. in the opposite direction to the first long edge portion 31 relative to the direction of the longitudinal axis LA, i.e. away from the center portion or centerline of the blade segment.

[0037] The first bend 32a is followed by a substantially straight or slightly curved short edge portion 32b. The direction of the short edge portion 32b is arranged to deviate from the direction of the longitudinal axis LA to a direction different from the first long edge portion 31, i.e., deviate from the direction of the longitudinal axis LA to a direction opposite to the first long edge portion 31, i.e., away from the center portion or centerline of the blade segment.

[0038] The short edge portion 32b is followed by a second bend 32c, which turns away from the direction of the first short edge portion 32b, i.e., turns in the opposite direction of the short edge portion 32b relative to the direction of the longitudinal axis LA, i.e., towards the center portion or centerline of the blade segment. Thus, the second bend 32c turns in the opposite direction of the first bend 32a relative to the direction of the longitudinal axis LA.

[0039] The first bend 32a, the short edge portion 32b and the second bend 32c provide an elbow 32 in the first side edge 22 of the blade segment. In other words, the elbow 32 in the first side edge 22 of the blade segment consists of the first bend 32a, the short edge portion 32b after the first bend 32a and the second bend 32c after the short edge portion 32b.

[0040] The second bend 32c or elbow 32 is followed again by a substantially straight second long edge portion 33, the direction of which is arranged to deviate from the direction of the longitudinal axis LA of the blade segment to the same direction as the first long edge portion 31, i.e. towards the central portion or centre line of the blade segment. In other words, the second bend 32c and therefore the elbow 32 is followed by a substantially straight second long edge portion 33, the direction of which is arranged to deviate from the direction of the longitudinal axis LA of the blade segment to the same direction as the first long edge portion 31. Thus, the second long edge portion 33 is arranged to deviate from the direction of the longitudinal axis LA to the same direction as the first long edge portion 31 with respect to the direction of the longitudinal axis LA.

[0041] Furthermore, in the direction from the inner end edge 20 towards the outer end edge 21, the second side edge 23 of the blade segment 4, 4a, 4b, 8, 8a, 8b comprises an at least substantially straight first long edge portion 41. The direction of the first long edge portion 41 is arranged to deviate from, i.e., relative to, the direction of the longitudinal axis LA of the blade segment such that the first long edge portion 41 is oriented away from a central portion or a centerline of the blade segment.

[0042] The first long edge portion 41 is followed by a first bend 42a which turns away from the first long edge portion 41 , i.e. in a direction opposite to the first long edge portion 41 relative to the longitudinal axis LA, i.e. towards a center portion or centerline of the blade segment.

[0043] The first bend 42a is followed by a substantially straight or slightly curved short edge portion 42b. The direction of the short edge portion 42b is arranged to deviate from the direction of the longitudinal axis LA to a direction different from the first long edge portion 41, i.e., deviate from the direction of the longitudinal axis LA to a direction opposite to the first long edge portion 41, i.e., towards the centerline of the blade segment.

[0044] The short edge portion 42b is followed by a second bend 42c which turns away from the direction of the first short edge portion 42b, i.e., turns to a direction opposite to the short edge portion 42b relative to the direction of the longitudinal axis LA, i.e., away from the center line of the blade segment. Thus, the second bend 42c turns in a direction opposite to the first bend 42a relative to the longitudinal axis LA.

[0045] The first bend 42a, the short edge portion 42b and the second bend 42c provide an elbow 42 in the second side edge 23 of the blade segment. In other words, the elbow 42 in the second side edge 23 of the blade segment consists of the first bend 42a, the short edge portion 42b after the first bend 42a and the second bend 42c after the short edge portion 42b.

[0046] The second bend 42c or elbow 42 is followed again by a substantially straight second long edge portion 43, the direction of which is arranged to deviate from the direction of the longitudinal axis LA of the blade segment to the same direction as the first long edge portion 41, i.e. away from the center portion or centerline of the blade segment. In other words, the second bend 42c and therefore the elbow 42 is followed by a substantially straight second long edge portion 43, the direction of which is arranged to deviate from the direction of the longitudinal axis LA of the blade segment to the same direction as the first long edge portion 41. Therefore, the second long edge portion 43 is arranged to deviate from the direction of the longitudinal axis LA to the same direction as the first long edge portion 41.

[0047] When further considered Figure 5 When the blade segments are 4 and 8, Figure 5The first side edge 22 of the blade segment 4, 8 also includes another bevel 34 after the second long edge portion 33. Therefore, the second long edge portion 33 is followed by a third bend 34a, which turns away from the direction of the second long edge portion 33, i.e., turns relative to the direction of the longitudinal axis LA to the opposite direction of the second long edge portion 33, i.e., away from the center portion or center line of the blade segment.

[0048] The third bend 34a is followed by a second substantially straight or slightly curved short edge portion 34b. The direction of the second short edge portion 34b is arranged to deviate from the direction of the longitudinal axis LA to a direction different from the second long edge portion 33, i.e., deviate from the direction of the longitudinal axis LA to a direction opposite to the second long edge portion, i.e., away from the center portion or centerline of the blade segment.

[0049] The second short edge portion 34b is followed by a fourth bend 34c, which turns away from the direction of the second short edge portion 34b, i.e., turns to the direction opposite to the second short edge portion 34b with respect to the direction of the longitudinal axis LA, i.e., towards the center portion or centerline of the blade segment. Thus, the fourth bend 34c turns in the direction opposite to the third bend 34a with respect to the longitudinal axis LA.

[0050] The third bend 34a, the second short edge portion 34b and the fourth bend 34c provide a second elbow 34 in the first side edge 22 of the blade segment. In other words, the second elbow 34 in the first side edge 22 of the blade segment consists of the third bend 34a, the second short edge portion 34b after the third bend 34a and the fourth bend 34c after the short edge portion 34b.

[0051] The fourth bend 34c or the second elbow 34 is again followed by a substantially straight third long edge portion 35, the direction of which is arranged to deviate from the direction of the longitudinal axis LA of the blade segment to the same direction as the first long edge portion 31 and the second long edge portion 33, i.e., towards the center portion or centerline of the blade segment. In other words, the fourth bend 34c and therefore the second elbow 34 is followed by a substantially straight third long edge portion 35, the direction of which is arranged to deviate from the direction of the longitudinal axis LA of the blade segment to the same direction as the first long edge portion 31 and the second long edge portion 33. Therefore, the third long edge portion 35 is arranged to deviate from the direction of the longitudinal axis LA to the same direction as the first long edge portion 31 and the second long edge portion 33.

[0052] The ratio of the length of the short edge portions 32 b , 34 b to the length of the long edge portions 31 , 33 , 35 is approximately 1:2 to 1:20.

[0053] Similarly, Figure 5 The second side edge 23 of the blade segment 4, 8 comprises a further bevel 44 after the second long edge portion 43. Thus, the second long edge portion 43 is followed by a third bend 44a which turns away from the direction of the second long edge portion 43, i.e., turns to a direction opposite to the second long edge portion with respect to the direction of the longitudinal axis LA, i.e., towards a central portion or a centerline of the blade segment.

[0054] The third bend 44a is followed by a second substantially straight or slightly curved short edge portion 44b. The direction of the second short edge portion 44b is arranged to deviate from the direction of the longitudinal axis LA to a direction different from the second long edge portion 43, i.e., deviate from the direction of the longitudinal axis LA to a direction opposite to the second long edge portion, i.e., towards the center portion or centerline of the blade segment.

[0055] The second short edge portion 44b is followed by a fourth bend 44c, which turns away from the direction of the second short edge portion 44b, i.e., turns to the direction opposite to the second short edge portion 44b with respect to the direction of the longitudinal axis LA, i.e., away from the center portion or centerline of the blade segment. Thus, the fourth bend 44c turns in the direction opposite to the third bend 44a with respect to the direction of the longitudinal axis LA.

[0056] The third bend 44a, the second short edge portion 44b and the fourth bend 44c provide a second elbow 44 in the second side edge 23 of the blade segment. In other words, the second elbow 44 in the second side edge 23 of the blade segment consists of the third bend 44a, the second short edge portion 44b after the third bend 44a and the fourth bend 44c after the second short edge portion 44b.

[0057] The fourth bend 44c or the second elbow 44 is again followed by a substantially straight third long edge portion 45, the direction of which is arranged to deviate from the direction of the longitudinal axis LA of the blade segment to the same direction as the first long edge portion 41 and the second long edge portion 43, i.e. away from the center portion or centerline of the blade segment. In other words, the fourth bend 44c and therefore the second elbow 44 is followed by a substantially straight third long edge portion 45, the direction of which is arranged to deviate from the direction of the longitudinal axis LA of the blade segment to the same direction as the first long edge portion 41 and the second long edge portion 43. Therefore, the third long edge portion 45 is arranged to deviate from the direction of the longitudinal axis LA to the same direction as the first long edge portion 41 and the second long edge portion 43.

[0058] The ratio of the length of the short edge portions 42 b , 44 b to the length of the long edge portions 41 , 43 , 45 is approximately 1:2 to 1:20.

[0059] exist Figure 4a , Figure 4b and Figure 5 In an embodiment of the blade segment, the two side edges 22, 23 of the blade segment include at least two edge portions 31, 33, 35, 41, 43, 45, and the at least two edge portions are arranged to deviate from the direction of the longitudinal axis LA of the blade segment 4, 4a, 4b, 8, 8a, 8b and are connected by an elbow portion 32, 34, 42, 44 between each two edge portions 31, 33, 35, 41, 43, 45.

[0060] exist Figure 4a , Figure 4b and Figure 5 In an embodiment of the blade segment of , the configuration of the side edges 22, 23 is also arranged to be offset from the mirror image with respect to the longitudinal axis LA of the blade segment. In other words, Figure 4a , Figure 4b and Figure 5 The side edges of the blade segments are not mirror images of each other with respect to the longitudinal axis LA of the blade segments 4, 4a, 4b, 8, 8a, 8b at the center line of the blade segments 4, 4a, 4b, 8, 8a, 8b.

[0061] Typically, according to the solution disclosed herein, at least one side edge 22, 23 of a blade segment 4, 4a, 4b, 8, 8a, 8b comprises at least two edge portions 31, 33, 35, 41, 43, 45, the directions of the at least two edge portions being arranged to deviate from the direction of the longitudinal axis LA of the blade segment 4, 4a, 4b, 8, 8a, 8b, and the at least two edge portions being connected by an elbow portion 32, 34, 42, 44 between each two edge portions 31, 33, 35, 41, 43, 45.

[0062] According to another embodiment, the direction of the edge portions 31, 33, 35, 41, 43, 45 at specific side edges 22, 23 is arranged to deviate from the direction of the longitudinal axis LA to the same direction, and the elbow portions 32, 34, 42, 44 are turned away from the edge portions 31, 33, 35, 41, 43, 45 so that they deviate from the direction of the longitudinal axis LA of the blade segment to a direction different from the edge portions 31, 33, 35, 41, 43, 45.

[0063] According to an embodiment of the blade segment, as in Figure 68, the extent of the elbow 32, 34 (or more specifically the length of the short edge portion 32b, 34b) can be arranged so that it substantially does not exceed the edge axis LA', thereby providing a continuous slit-like opening 14, 15 between adjacent segments 4, 8. In other words, in this embodiment, the elbow 32, 34 is arranged so as not to exceed the longitudinal axis LA' of the blade segments 4, 8 at the first side edge 22 of the blade segments 4, 8.

[0064] According to an embodiment of the blade segment, as in Figure 6 8, the extent of the elbows 42, 44 can be arranged so that the elbows extend either up to the edge axis LA' (as in the case of the elbow 44), or extend beyond the edge axis LA' (as in the case of the elbow 42). In other words, in this embodiment, the elbows 42, 44 are arranged to extend at the second side edge 22 of the blade segments 4, 8 up to the longitudinal axis LA' of the blade segments 4, 8, or even extend beyond the longitudinal axis LA' of the blade segments 4, 8 at the second side edge 22 of the blade segments 4, 8. If the opposing side edges 22, 23 are not parallel, the elbows can exceed the edge axis LA', even to the extent that they can come into contact with the adjacent segments, thereby providing a discontinuous slit-like opening 14, 15 between the adjacent segments 4, 8.

[0065] The configuration of the side edges of the disclosed blade segments provides a gentle zigzag shape that deviates from the longitudinal axis of the blade segments. When the configuration of the opposing side edges is selected to cooperate with the configuration of the first-mentioned side edges, it provides a longitudinal slit-like opening (i.e., a flow path) between adjacent blade segments for supplying the fiber material to be refined into the refining chamber between the stator and the rotor, and for discharging the refined fiber material out of the refining chamber. Therefore, the slit-like opening with a stepped or stepped opening configuration has a center line, the direction of which deviates from the direction of the axis of the blade segment at least at a large part of the extension of the opening. This has the following effect: the angle of incidence between the opening in the rotor and the opening in the stator varies in the axial direction of the refiner or the longitudinal axis of the blade segment and the edge axis, resulting in the point of incidence between the opening in the rotor and the opening in the stator leaving the axial direction of the refiner or the longitudinal axis of the blade segment. This in turn has the effect that possible flow pulse changes during operation of the refiner and the vibrations that occur as a result can be reduced.

[0066] According to an embodiment, the width of the slit-shaped opening is between 10 mm and 25 mm.

[0067] According to an embodiment, edge portions at the same side edge 22, 23 of the blade segments and arranged to deviate from the direction of the longitudinal axis LA of the blade segments to the same direction are substantially parallel. This has the effect that a substantially constant width opening is easily achieved between adjacent blade segments.

[0068] According to an embodiment, each side edge of the blade segment comprises at least one elbow. This has the effect that both side edges of the blade segment have a gentle zigzag shape, thereby preventing a large part of the side edge from following the longitudinal axis of the blade segment and thus preventing the formation of open parts that could lead to a tendency to vibration during operation of the refiner.

[0069] According to an embodiment, the elbows at the opposite side edges are located at the same normal height relative to the longitudinal axis LA of the blade segment. Figure 5 The dashed line in FIG, denoted by reference N, schematically shows a normal to the longitudinal axis LA of the blade segment. This has the effect of providing an opening having a substantially constant width along the longitudinal extension of the opening.

[0070] According to an embodiment, the number of elbows at each side edge 22, 23 is one to ten, preferably two to six, or two to seven, or two to eight. If the number of elbows at the side edges is reasonable, the deviation of the extension direction of the opening from the longitudinal axis of the blade segment can be ensured. Too dense zigzags of the side edges of the blade segments may lead to a continuous back-and-forth type flow path of the pulp, which is ultimately not much different from a design that may not be desired in terms of vibration.

[0071] According to an embodiment, the deviation angle of the elbow from the longitudinal axis LA of the blade segment is about 10 to 90 degrees, preferably 10 to 60 degrees, and more preferably 10 to 50 degrees.

[0072] According to an embodiment, the extension direction of the elbow is substantially parallel to the extension direction of the teeth. In other words, the elbow is arranged to form an angle which is substantially parallel to the angle of the teeth applied in the blade segment.

[0073] According to an embodiment, the configuration of the side edges 22, 23 is arranged to be mirror-off with respect to the longitudinal axis of the blade segment, or 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.

[0074] It is obvious to a person skilled in the art that, as technology advances, the inventive concept can be implemented in various ways.The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.

Claims

1. A blade segment (4, 8) of a refiner (1) for refining fibrous material, the blade segment (4, 8) comprising: a first end edge (20) and a second end edge (21), the second end edge being opposite to the first end edge in the direction of the longitudinal axis (LA) of the blade segment (4, 4a, 4b, 8, 8a, 8b), a first side edge (22) and a second side edge (23), the second side edge being opposite to the first side edge, the first side edge (22) and the second side edge (23) extending between the first end edge (20) and the second end edge (21), a fine grinding surface (5, 9) comprising teeth (26) and grooves (27) between the teeth on the front surface (25) of the blade segment (4, 8), It is characterized in that At least one side edge (22, 23) comprises at least two long edge portions (31, 33, 35, 41, 43, 45) which are arranged to deviate from the direction of the longitudinal axis (LA) of the blade segment (4, 4a, 4b, 8, 8a, 8b) and are connected by an elbow (32, 34, 42, 44) between each two edge portions (31, 33, 35, 41, 43, 45). The elbow portion (32, 34, 42, 44) is composed of a first bend (32a, 34a, 42a, 44a), a short edge portion (32b, 34b, 42b, 44b) after the first bend (32a, 34a, 42a, 44a), and a second bend (32c, 34c, 42c, 44c) after the short edge portion (32b, 34b, 42b, 44b), wherein the long edge portions (31, 33, 35, 41, 43, 45) are arranged to deviate to the same direction relative to the direction of the longitudinal axis (LA), and the elbow portions (32, 34, 42, 44) turn away from the long edge portions (31, 33, 35, 41, 43, 45) to deviate to a direction different from that of the long edge portions (31, 33, 35, 41, 43, 45) relative to the direction of the longitudinal axis (LA).

2. The blade segment according to claim 1, characterized in that Both side edges (22, 23) include at least two long edge portions (31, 33, 35, 41, 43, 45), which are arranged 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 elbow portion (32, 34, 42, 44) between each two edge portions (31, 33, 35, 41, 43, 45).

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

4. A blade segment according to any one of the preceding claims, characterized in that In the direction from the first end edge (20) toward the second end edge (21), the side edge (22, 23) comprises at least: a straight first long edge portion (31, 41) arranged to deviate from the direction of the longitudinal axis (LA) of the blade segment (4, 4a, 4b, 8, 8a, 8b), a first bent portion (32a, 42a) after the first long edge portion (31, 41) and turned away from the direction of the first long edge portion (31, 41), and a straight short edge portion (32b, 42b) after the first bent portion (32a, 42a) and arranged to deviate from the direction of the longitudinal axis (LA) of the blade segment (4, 4a, 4b, 8, 8a, 8b) to a direction different from that of the first long edge portion (31, 41). ), a second bend (32c, 42c) which is behind the short edge portion (32b, 42b) and turns away from the short edge portion (32b, 42b), and a straight second long edge portion (33, 43) which is behind the second bend (32c, 42c) and is arranged to deviate from the direction of the longitudinal axis (LA) of the blade segment (4, 4a, 4b, 8, 8a, 8b) to the same direction as the first long edge portion (31, 41), wherein the first bend (32a, 42a), the short edge portion (32b, 42b) and the second bend (32c, 42c) provide the elbow portion (32, 42) in the side edge (22, 23) of the blade segment (4, 4a, 4b, 8, 8a, 8b).

5. The blade segment according to any one of claims 2 to 4, characterized in that Each side edge (22, 23) comprises at least one elbow (32, 34, 42, 44).

6. The blade segment according to any one of claims 2 to 5, characterized in that The elbows (32, 34, 42, 44) at the opposite side edges (22, 23) are located at the same normal (N) height relative to the longitudinal axis (LA).

7. The blade segment according to any one of claims 2 to 6, characterized in that The number of the elbows (32, 34, 42, 44) at each side edge (22, 23) is one to ten.

8. The blade segment according to claim 7, characterized in that The number of the elbows (32, 34, 42, 44) at each side edge (22, 23) is two to seven.

9. A blade segment according to any one of the preceding claims, characterized in that The offset angle of the elbow (32, 34, 42, 44) relative to the longitudinal axis (LA) is 10 to 90 degrees.

10. A blade segment according to any one of the preceding claims, characterized in that The extending direction of the elbow-shaped portion (32, 34, 42, 44) is parallel to the extending direction of the blade teeth (26).

11. The blade segment according to any one of the preceding claims, characterized in that The side edges (22, 23) are not mirror images of each other with respect to a longitudinal axis (LA) of the blade segment (4, 4a, 4b, 8, 8a, 8b).

12. A blade segment according to any one of the preceding claims, characterized in that The elbow portion (42) is arranged to extend beyond an 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 (23) of the blade segment (4, 4a, 4b, 8, 8a, 8b).

13. A blade segment according to any one of the preceding claims, characterized in that At least at one end of the blade segment (4, 4a, 4b, 8, 8a, 8b) and at two corners of the blade segment (4, 4a, 4b, 8, 8a, 8b), shoulders (50, 51, 52, 53) are provided, which are used to contact with adjacent blade segments (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).

14. A blade segment according to any one of the preceding claims, characterized in that 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.

15. A refiner for refining fiber material, characterized in that: The refiner (1) comprises at least one blade segment (4, 4a, 4b, 8, 8a, 8b) according to any one of claims 1 to 14.

16. The refiner according to claim 15, characterized in that In the refining element (3, 6) of the refiner (1), there is a continuous slit-like opening (14, 15) between adjacent blade segments (4, 4a, 4b, 8, 8a, 8b).

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

Images