grinding plate

Abstract

A grinding plate for a refiner (100) for refining lignocellulosic material, the grinding plate (30) having an active surface (1; 1') comprising a pattern of knives (10) and grooves (20) arranged in a plurality of pattern areas (41; 41'), wherein the pattern areas (41; 41') are positioned side by side to each other to cover at least a part of the active surface (1; 1'). Each of the pattern areas (41; 41') has a length I extending between a first end (43a) and a second end (43b) of the pattern area (41; 41') and a width w extending between two side edges (45a, 45b) of the pattern area, wherein the distance between the two side edges (45a, 45b) is smallest in the first end (43a) of the pattern area (41; 41') and increases towards the second end (43b) of the pattern area. Each of the pattern areas (41; 41') is positioned on the active surface (1; 1') such that a centre line c of the pattern area (41; 41') is arranged at an angle p of between 10-60° to a radius R of the grinding plate (30).

Description

Technical Field

[0001] This invention relates to a grinding disc for a refiner (pulverizer) for refining lignocellulosic materials. The invention also relates to a grinding wheel for such a grinding disc. Background Technology

[0002] For example, a common grinding mill for lignocellulosic materials includes two opposing rotating discs between which the material is ground or defibrated. This pair of opposing rotating discs may specifically include a rotating disc called a rotor and a stationary disc called a stator. Alternatively, this pair of opposing rotating discs may include two rotating discs rotating in opposite directions. These grinding discs, or at least one of them, include an effective surface that may include a set of bars and dams for providing efficient grinding of the material. The effective surface of the grinding disc is at least a portion of the surface on which the material flows and is processed. The effective surface is typically provided on multiple grinding discs, which are separate components to be attached to the grinding disc, thus the effective surface of the grinding disc consists of multiple grinding discs. The bars may be substantially radially extending and projecting structures arranged on the effective surface of the grinding disc and primarily used to achieve efficient grinding of the lignocellulosic material. Dams are also projecting structures provided on the effective surface, but they are generally not arranged radially. Instead, dams are provided on the effective surface in such a way that a specific dam contacts or connects two adjacent bars. That is, the slurry baffle is configured such that it spans the direction connecting two adjacent cutter teeth. This direction can be approximately orthogonal to the cutter teeth, but it can also be configured at an angle relative to the cutter teeth. The specific purpose of the slurry baffle is to lift the material flowing in the area between the cutter teeth (hereinafter referred to as the groove) in an upward direction toward the disc gap, which is defined as the gap between two opposing grinding discs, for example, the disc gap between the rotor and stator, or the disc gap separating two opposing rotating discs. The material is ground or fibrous in the disc gap between the discs. In the common case where each cutter tooth is connected to one or more slurry baffles, the natural result of the geometry is the creation of many partially enclosed or defined areas between adjacent cutter teeth. The main portion of the grinding material will flow in these areas. A specific problem associated with grinding discs equipped with cutter teeth and slurry baffles is that, as structures protruding from the surface of the grinding disc, the cutter teeth and slurry baffles wear down due to their abrasive contact with the material to be ground. As a result, the efficiency of the grinding disc will decrease over time, and the grinding discs will need to be replaced to achieve satisfactory quality grinding of materials such as slurries. Summary of the Invention

[0003] The object of this invention is to provide an improved grinding disc for use in a fine grinding mill for fine grinding of lignocellulosic materials.

[0004] Another object of the present invention is to provide a grinding disc and grinding discs used in the grinding disc, which, when used in a fine grinding mill, will provide an effective fine grinding process, thereby providing high-quality finely ground materials.

[0005] According to one aspect of the invention, a grinding disc for a fine grinding mill for finely grinding lignocellulosic materials is provided. The grinding disc has an effective surface that, when used in the fine grinding mill, faces another grinding disc, wherein the effective surface includes multiple patterned regions. The pattern of teeth and grooves in an area, wherein the pattern areas are positioned side by side to cover at least a portion of the effective surface, wherein each of the pattern areas has a length l extending between a first end and a second end of the pattern area and a width w extending between two side edges extending between the first end and the second end of the pattern area, wherein the second end is located at the outer periphery of the effective surface and the first end is located closer to the center C of the grinding disc than the second end, and wherein the distance between the two side edges is minimum at the first end of the pattern area and increases toward the second end of the pattern area, and wherein each of the pattern areas is positioned on the effective surface such that the center line c extending from the first end of the pattern area to the second end is set at an angle p with respect to the radius R of the grinding disc passing through the center position cp of the pattern area, the angle p being between 10° and 60°, wherein at least some of the teeth extend along a direction between the two side edges of the pattern area in which the teeth are provided, and wherein at least 80% of the total number of teeth 10 provided in a pattern area extends only within the pattern area.

[0006] According to another aspect of the invention, a grinding disc is provided for use in a grinding wheel according to the invention, wherein the grinding disc comprises a portion of the effective surface of the grinding wheel.

[0007] Therefore, an effective surface with a pattern of teeth and grooves that provides a more seamless volume reduction is achieved. The patterned areas are arranged side-by-side on the effective surface in a direction inclined relative to the radial direction. The design of the effective surface according to the invention provides a uniform fiber quality with less dust and debris. Furthermore, according to the invention, when the grinding discs are used in a fine grinder to finely grind lignocellulosic materials, uniform wear and a longer lifespan of the effective surface pattern are achieved. By providing teeth and grooves in the patterned areas according to the invention, wherein most of the teeth do not extend beyond the provided patterned areas, the size and extension direction of the teeth in each patterned area can be freely varied within each patterned area. Therefore, the design of the effective surface can be easily optimized, for example, to achieve volume reduction and thus uniform flow of material on the effective surface. Due to the design of the effective surface pattern according to the invention, a more seamless volume reduction is provided, which will provide a more stable feed of wood chips, less micropulsation between grinding discs, less point wear, and therefore lower energy consumption.

[0008] In one embodiment of the invention, the patterned region is defined at its second end by a portion s of the outer periphery of the effective surface, which extends between the two side edges of the patterned region. The length of the portion s corresponds to the arc length of a circular sector with a central angle between 1° and 15° or between 4° and 12° in the circle with the outer periphery of the effective surface.

[0009] In one embodiment of the present invention, the center line c of the pattern area is set at an angle p with the radius R of the grinding disc, wherein the angle p is between 20° and 40°.

[0010] In some embodiments of the invention, each of the cutting teeth has a length, thickness, and height, wherein the height extends vertically from the effective surface, such that the thickness bw of the cutting teeth in each patterned area is the same or decreases toward the outer periphery of the effective surface.

[0011] In some embodiments of the invention, the distance gw between adjacent teeth in the same patterned area is the same or the distance towards the outer periphery of the effective surface is reduced. By employing the thickness of the teeth and the distance between adjacent teeth, a denser pattern can be formed towards the outer periphery of the effective surface, thereby providing a suitable volume reduction.

[0012] In some embodiments of the invention, the angle b between the length extension direction of each tooth in the patterned region and the radius R of the grinding disc passing through the midpoint of that tooth is the same or decreases toward the outer periphery of the effective surface. For teeth positioned closer to the outer periphery, a reduced angle b can be provided to counteract the increased acceleration of the material caused by centrifugal force closer to the outer periphery.

[0013] In some embodiments of the invention, in the first portion of the patterned region extending from the first end toward the second end of the patterned region, the cutting teeth do not extend continuously between the first and second side edges, but instead leave an open wedge-shaped region with no cutting teeth between adjacent patterned regions. Therefore, material feeding is improved, and the risk of material getting stuck between the cutting teeth is reduced.

[0014] In some embodiments of the invention, at least three end teeth are present in each patterned region. These end teeth are shorter than adjacent teeth in the direction toward the first end of the patterned region. These end teeth are positioned to be closest to the second end of the patterned region, whereby each end tooth extends toward the outer periphery of the effective surface.

[0015] In some embodiments of the invention, the slurry baffles are disposed on the effective surface, such that each slurry baffle extends between two adjacent cutter teeth, wherein at least four slurry baffles are positioned such that they together form a continuous slurry baffle disposed along a smooth curve.

[0016] In some embodiments of the invention, each patterned region includes a continuous final stop comprising at least four stops connecting at least five end teeth of the patterned region. These end teeth are positioned closest to the second end of the patterned region, thereby connecting the continuous final stops of multiple patterned regions. The combined continuous final stops are thus arranged substantially along the outer periphery of the effective surface. This improves the load distribution and strengthens the teeth within each patterned region. It also benefits the manufacturing process of the effective surface. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a fine grinding mill, in which a grinding disc according to the present invention can be used.

[0018] Figure 2 This is a schematic diagram of a cross-section of a grinding disc arrangement, wherein a grinding disc according to the present invention can be used.

[0019] Figure 3 This is a schematic top view of a grinding disc according to an embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of a grinding disc attached to a grinding disk such as a rotor disk or stator disk.

[0021] Figure 5A This is a schematic diagram of the effective surface of a grinding disc according to an embodiment of the present invention. Figure 5B and 5C Showing more details Figure 5A A portion of the effective surface.

[0022] Figure 6This is a schematic diagram of the effective surface of a grinding disc according to an embodiment of the present invention.

[0023] Figures 7A-7C This is a schematic diagram of a grinding disc according to different embodiments of the present invention. Detailed Implementation

[0024] Throughout the accompanying drawings, the same reference numerals are used for similar or corresponding elements. Generally, unless explicitly given and / or implied from the context of use, all terms used herein are to be interpreted according to their ordinary meaning in the relevant art. Where appropriate, any feature of any embodiment disclosed herein may be applied to any other embodiment.

[0025] To better understand the invention, it may be helpful to begin with a brief description of a general fine grinding mill. For this purpose, refer to... Figure 1 The diagram schematically illustrates a fine grinding machine that can be used with the present invention. Figure 1 An exemplary slurry grinding mill 100 is schematically shown in cross-sectional view. This arrangement is housed in a housing 26, which represents the outer casing of the grinding mill equipment and all its components; this is not essential for understanding the invention. Examples of components not shown include an electric motor for driving, for example, a rotating shaft, a feeding mechanism for the lignocellulosic material, etc. Inside a second housing 31 are the rotor grinding disc 30 and the stator grinding disc 30. Aligned along the axis. The rotor grinding disc 30 is attached to a rotating shaft 15 arranged on a bearing 16. The rotating shaft 15 is connected to a motor (not shown), which rotates the shaft 15, thereby rotating the rotor grinding disc 30. The stator grinding disc 30 faces the rotor grinding disc 30. A centrally positioned through-hole 32 may be provided, extending between the feed channel 14 for lignocellulosic material and the finishing zone 19. Feeding the material into the finishing zone 19 does not necessarily require passing through... Figure 1 and 2 Instead of providing a centrally located through-hole as shown, it can be provided via through-holes distributed in another manner rather than being exactly centered. In some embodiments, the rotor grinding disc 30 may be provided with a center plate 17 having a surface facing the lignocellulosic material inflow. The surface of the center plate 17 may be provided with a structure to guide the lignocellulosic material outward. Rotor grinding disc 30 and / or stator grinding disc 30 The grinding disc includes an effective surface for slurry redirection and grinding. The effective surface typically includes a pattern of teeth and slurry baffles, which will be described in more detail below. The grinding disc usually comprises multiple grinding discs, each including a portion of the effective surface. The grinding discs can be attached to or removed from the grinding disc, and therefore can be replaced when the pattern on the effective surface has worn away. In some fine grinding mills, two rotor grinding discs may be present instead of a rotor grinding disc and a stator grinding disc, with the two rotor grinding discs rotating in opposite directions. The present invention can also be applied to such fine grinding mills.

[0026] During use, lignocellulosic materials such as wood chips or precast wood, for example pulp, are fed through feed channel 14 by means of a feeding mechanism, such as a screw feeder (not shown). The material passes through stator grinding disc 30. The hole 32 is inserted into region 19. Region 19 is essentially composed of rotor 30 and stator grinding disc 30. The open area between them is defined, and this area can be quite small during operation. The lignocellulosic material flowing into area 19 will be incident on the center plate 17 on the rotor grinding disc 30. The center plate 17 is used to deflect the lignocellulosic material toward the grinding discs on the rotor and / or stator grinding discs.

[0027] To provide a more detailed description of the rotor-stator arrangement that can be used with the present invention, see reference to Figure 2 . Figure 2 A cross-sectional side view of the rotor-stator arrangement housed in a casing 31, such as that described above, in a fine grinding mill is shown. Rotor grinding disc 30 and stator grinding disc 30 are also shown. The rotor grinding disc 30 is arranged to rotate around a rotation axis. The rotor grinding disc 30 faces the stator grinding disc 30. An effective surface 1 is provided on the surface of the stator grinding disc 30. An effective surface 1 can also be provided on the surface facing the rotor grinding disc 30. As described above, the effective surface 1 can be provided on one or more grinding discs 2. These are respectively provided on the rotor grinding disc 30 and the stator grinding disc 30. The grinding discs 2 on the surface can be designed identically or differently. The grinding disc according to the invention can be a rotor grinding disc 30 and a stator grinding disc 30. One or both of them, or in the case of two rotating discs, one or both of the two rotor grinding discs. In some types of fine grinding mills, the rotor grinding disc and the stator grinding disc can be referred to as grinding disc holders because one of the uses of the grinding disc is to support the grinding discs. Similarly, in Figure 2 The image shows inlet 32 ​​for the lignocellulosic material undergoing fine grinding. Inlet 32 ​​is arranged on the stator grinding disc 30. In the central region of the rotor disc 30, however, as mentioned above, the central position of inlet 32 ​​is not necessary. Center plate 17 is arranged in the central region of the rotor disc 30, opposite to inlet 32. (See above for reference.) Figure 1 The purpose of the described center plate 17 is to distribute material falling from the inlet 32 ​​toward the outer section of the rotor grinding disc 30. That is, the center plate 17 functions to distribute material toward the effective surface 1 arranged on the rotor grinding disc 30. In an example including two rotor grinding discs rotating in opposite directions, the inlets for feeding material can be arranged differently as is known in the art.

[0028] The above has been combined Figure 1 and 2 A general fine grinding mill that can be utilized by the present invention is described. Figure 3 A schematic diagram of a grinding disc 2 according to an embodiment of the present invention is provided. The grinding disc 2 is disposed on a grinding disk 30. This may be a rotor grinding disk 30 or a stator grinding disk 30. Both, but will be referred to simply as grinding disc 30 below. In this particular example, grinding disc 2 consists of circular sectors with a removed central portion. However, other possible geometries exist for the grinding disc, which will be discussed further below. Grinding disc 2 will be attached to grinding disc 30. As mentioned above, grinding disc 2 can be configured in the shape of a circular sector, which optionally has a removed central region to make room for center plate 17 or inlet 32. Grinding disc 2 can also be configured in the shape of another part of a circle. Grinding disc 30 can therefore be provided with a plurality of grinding discs 2, thereby completely or partially covering it. In the case where grinding disc 2 forms part of rotor grinding disc 30, the central region of rotor grinding disc may include center plate 17 as described above.

[0029] Figure 3 A grinding disc 2 is shown, having an inner perimeter 18a, an outer perimeter 18b, a first side edge 21a, and a second side edge 21b. The inner perimeter 18a is the perimeter of the grinding disc 2, and when the grinding disc 2 is attached to the grinding disk 30, the inner perimeter 18a is designed to be closest to the center C of the grinding disk 30. The grinding disc 2 includes a pattern of cutting teeth 10 and grooves 20 on its upper surface 1a, the surface that will face the material flow, and this pattern becomes part of the effective surface 1 of the grinding disk 30 when the grinding disc 2 is attached to the grinding disk 30.

[0030] Figure 4 When the grinding disc 30 is attached to the stator or rotor Figure 3 A simplified view of the grinding disc 2, which has a center C. The radial direction is indicated by an arrow labeled R. The radial direction extends from the center C of the grinding disc 30 toward the periphery of the grinding disc 30, passing through the inner periphery 18a and the outer periphery 18b of the grinding disc 2 in its path.

[0031] In a fine grinding mill in which the grinding disc according to the invention can be used, wood chips are finely ground into fibers or pulp. Large particles are finely ground into smaller particles. The pattern of the teeth and grooves on the effective surface 1 of the grinding disc 30 should appropriately provide a reduction in volume towards the outer periphery. A coarser pattern can be provided in the center of the grinding disc, and a denser pattern can be provided in the periphery. The construction, size, spacing, and orientation of the teeth in the pattern should be suitable for achieving this purpose. A seamless design, as far as possible, is suitable for both fiber quality and uniformity, as well as for the wear of the grinding disc.

[0032] Figure 5A The effective surface 1 of a grinding disc 30 according to an embodiment of the present invention is schematically shown. According to the present invention, a grinding disc 30 is provided for use in a fine grinding mill 100 for fine grinding of lignocellulosic materials. A grinding disc 2 for use in the grinding disc 30 is also provided. Figure 5A The effective surface 1 shown can be set as follows: Figure 3 The grinding discs 2 are shown on the grinding wheel 30. The grinding discs 2 are positioned on the grinding wheel 30 such that... Figure 5A The effective surface 1 of the illustrated combination is disposed on the grinding disc 30. When used in a fine grinding mill, the effective surface 1 will face another grinding disc, and the material to be finely ground will thus flow between the two grinding discs over the effective surface 1. The effective surface 1 includes a pattern of teeth 10 and grooves 20 disposed in a plurality of patterned regions 41, wherein the patterned regions 41 are positioned side by side to cover at least a portion of the effective surface 1. Grooves 20 are formed between two adjacent teeth 10. The effective surface 1 is defined by an inner periphery 118a and an outer periphery 118b. Within the inner periphery 118a of the effective pattern 1, other structures for conveying and / or finely grinding material may be provided on the grinding disc 30. Openings for receiving material may also be provided, as described above regarding Figure 1 and 2 As described. In this embodiment of the invention, the patterned region 41 is only disposed radially outside the circular pattern boundary 119, which is disposed on the effective surface 1 between the inner periphery 118a and the outer periphery 118b. The circular pattern boundary 119 is an imaginary boundary and Figure 5A Only partially shown by dashed lines. Another type of inlet cutter 110 is provided in the region between the inner periphery 118a and the circular pattern boundary 119. The inlet cutter 110 is mainly configured to convey and distribute material from the material inlet toward the patterned region 41. In some grinding discs, an external blanked section may also be provided outside the outer periphery 118b of the effective surface 1. Section A of the effective surface 1 is enlarged and... Figure 5B The text is incomplete and contains several errors. A more accurate translation would require the full context. Figure 3 The grinding disc 2 is shown in the image. Figure 5B Only one pattern area 41 is fully shown in the image.

[0033] Each of the patterned regions 41 has a length l extending between a first end 43a and a second end 43b of the patterned region 41 and a width w extending between two side edges 45a, 45b of the patterned region 41. Both side edges 45a, 45b extend between the first end 43a and the second end 43b of the patterned region 41. The second end 43b of each patterned region 41 is located at the outer periphery 118b of the effective surface 1, and the first end 43a of each patterned region 41 is located closer to the center C of the grinding disc 30 than the second end 43b. The distance between the two side edges 45a, 45b is smallest at the first end 43a of the patterned region 41 and increases toward the second end 43b of the patterned region 41. The patterned region 41 is defined at its second end 43b by a portion s of the outer periphery 118b of the effective surface 1, which reaches between the two side edges 45a, 45b of the patterned region 41. In some embodiments of the invention, the length of the portion s corresponds to the arc length of a circular sector in a circle having a central angle between 1° and 15° or between 4° and 12°. Therefore, if the central angle of the circular sector is 1°, there will be space in the effective surface 1 for 360 patterned regions 41, while if the central angle of the circular sector is 15°, there will be space in the effective surface 1 for 24 patterned regions 41. Therefore, the width w of the patterned region 41 at its second end 43b will be adjusted so that the patterned regions 41 between 24 and 360 can be arranged side-by-side with their second ends 43b along the outer perimeter 118b of the effective surface 1.

[0034] Furthermore, each of the patterned regions 41 is positioned on the effective surface 1 such that the center line c of the patterned region 41, extending from the first end 43a to the second end 43b, is set at an angle p with the radius R of the grinding disc 30 passing through the center position cp of the patterned region 41. This angle p is between 10° and 60°, or in some embodiments between 20° and 40°. Therefore, the patterned region 41 can be said to be tilted from an imaginary radial position to an inclined position, in which the center line c would be set along the radius of the grinding disc 30, and in the inclined position, the first end 43a of the patterned region 41 has rotated toward the outer periphery 118b, while the second end 43b has been fixed to the outer periphery 118b. When used for fine grinding of materials in a fine grinding mill, this tilting direction is coordinated to be opposite to the rotation direction of the grinding disc.

[0035] At least some of the cutting teeth 10 extend along the direction between the two side edges 45a, 45b of the patterned area 41 in which the cutting teeth 10 are provided. Most of the cutting teeth do not extend beyond the patterned area 41 in which they are provided; that is, the cutting teeth begin and end within the patterned area 41. For example, at least 80% or at least 90% of the total number of cutting teeth 10 provided within a patterned area 41 extends only within said patterned area 41. Therefore, each patterned area 41 includes its own set of cutting teeth 10. Thus, the size and direction of the extension of the cutting teeth within the patterned area 41 can vary freely within each patterned area. It is possible that, for example, one or two cutting teeth 10b may exist that extend above the side edges 45a, 45b of the patterned area into adjacent patterned areas, which will be discussed further below.

[0036] exist Figure 5A and 5B In the illustrated embodiment, except for the tooth closest to the second end 43b in the patterned region 41, referred to as the end tooth 10a, all the teeth 10 extend along the direction between the two side edges 45a, 45b of the patterned region 41. Each end tooth 10a in each patterned region 41 is shorter than its adjacent tooth 10 or end tooth 10a in the direction toward the first end 43a of the patterned region 41, thereby extending each end tooth 10a toward the outer periphery 118b of the effective surface 1. Figure 5A and 5B In the specific embodiment shown, it can also be seen that one of the teeth 10b reaches above the side edge 45b and enters the adjacent pattern area 41, where it will serve as the last and shortest end tooth 10a, which is the last tooth 10 preceding the end tooth 10a. This is not necessary, but may be suitable, for example, for manufacturing reasons.

[0037] Each of the cutting teeth 10 has a length, a thickness (bw), and a height, wherein the height extends vertically from the effective surface 1. The lengths of those cutting teeth 10 extend along the direction between the two side edges 45a, 45b of the patterned region 41, i.e., in some embodiments, all cutting teeth except the end cutting teeth 10a are positioned such that they almost reach between the two side edges 45a, 45b of the patterned region 41. The direction of extension of the cutting teeth 10 may not follow the shortest path between the two side edges 45a, 45b; however, in some embodiments, at least 75% of the length of the cutting teeth 10 in the patterned region 41 may be at least 75% of the width w of the patterned region 41 in which each corresponding cutting tooth is positioned. In some embodiments of the invention, at least 90% of the length of the cutting teeth 10 extending along the direction between the two side edges 45a, 45b of the patterned region 41 is at least 75% of the width w of the patterned region 41 in which each corresponding cutting tooth is positioned.

[0038] In such Figures 5A-5C In the illustrated embodiment of the invention, but not necessarily, the thickness bw of the serrations 10 within each patterned region 41 decreases toward the outer periphery 118b of the effective surface 1. This enables... Figure 5C As seen in the diagram. Therefore, in some embodiments, the cutting teeth 10 become thinner as they approach the outer periphery 118b. Reducing the thickness of the cutting teeth may be suitable because a denser pattern can be formed closer to the outer periphery 118b, where the material has been finely ground into smaller portions. However, in another embodiment of the invention, all or at least some of the cutting teeth 10 may have the same thickness.

[0039] In addition, in such Figures 5A-5C In the illustrated embodiment, but not necessarily, the distance gw between adjacent teeth 10 in the same patterned region 41 decreases toward the outer periphery 118b of the effective surface 1. This is in Figure 5C As shown, the distance gw has been marked. This can also be adapted to provide a denser pattern of teeth and grooves toward the outer periphery 118b. However, the distance between adjacent teeth 10 can also be the same throughout the patterned area. By employing the thickness of the teeth and the distance between adjacent teeth, a denser pattern toward the outer periphery of the effective surface can be provided, thereby providing a suitable volume reduction.

[0040] In addition, in such Figures 5A-5C In the illustrated embodiment, but not necessarily, the angle b between the length extension direction of each tooth 10 in the patterned area 41 and the radius R of the grinding disc 30 passing through the midpoint of that tooth decreases toward the outer periphery 118b of the effective surface 1. This decrease toward the outer periphery 118b means that the angle b decreases evenly toward the outer periphery 118b, thus eliminating the need for the angle b to change between each tooth 10. This... Figure 5A and 5C The diagram shows a method suitable for counteracting the increased acceleration of the material caused by centrifugal forces closer to the outer periphery. This may be suitable for the uniform distribution of material through the grinding mill. However, the length extension direction of the cutting teeth 10 can also be the same for all cutting teeth.

[0041] In addition, in such Figures 5A-5C In the illustrated embodiment, but not necessarily, in the first portion of the patterned region 41 extending from the first end 43a toward the second end 43b, the cutting teeth 10 do not extend continuously between the first side edge 45a and the second side edge 45b, but instead leave an open wedge-shaped region 47 without cutting teeth between adjacent patterned regions 41. This is in Figure 5C As shown in the diagram. Therefore, material feeding will be improved, and the risk of material getting stuck between the cutting teeth is reduced. This may be suitable for achieving a uniform distribution of material through a fine grinding mill.

[0042] exist Figure 3 In China (and in Figure 5B and 5C (The text in the original is incomplete and cannot be translated.) Figure 5A An embodiment of the grinding disc 2 with an effective surface 1 is shown. As described above, the grinding disc 2 is in the form of a circular sector with an opening in the middle. Multiple such grinding discs 2 are assembled onto the grinding disk 30 to form a shape as shown. Figure 5A The effective surface 1 is shown. However, the grinding disc can also have other shapes, such as, for example... Figure 7B and 7C The shape shown is such that each grinding disc is part of a circle with an open center, wherein the patterned area 41 remains intact, such that the grinding disc includes only the complete patterned area 41 and does not include... Figure 3 Part of the patterned area of ​​the grinding disc 2 shown.

[0043] Figure 6 An effective surface 1' according to another embodiment of the invention is schematically shown. However, most of the details are different. Figures 5A-5C The illustrated embodiment is the same and will not be described in detail again. The difference lies in that, in this embodiment, the slurry baffles 11 are disposed on the effective surface 1', whereby each slurry baffle 11 extends between two adjacent cutter teeth 10. The slurry baffles 11 may be configured to be substantially orthogonal to the cutter teeth 10, but may also be configured to be inclined relative to the cutter teeth 10. Each slurry baffle 11 connects two adjacent cutter teeth 10. The slurry baffles are configured to lift material from the groove 20 at regular intervals to improve the finishing process. Figures 7A-7C In the diagram, the three different shapes of grinding discs 102, 102', and 102'' are shown as corresponding to... Figure 6 Effective surface 1'. Figure 7A The details of the slurry baffle 11 are marked in the middle.

[0044] In some embodiments of the invention, a plurality of paddle stops 11, such as at least four paddle stops 11, are positioned such that they together form a continuous paddle stop arranged along an imaginary smooth curve. Figure 6 and Figures 7A-7C In the illustrated embodiment, each patterned region 41' includes a continuous baffle 11a disposed along one of the side edges 45b. In this embodiment, eighth adjacent blades 10 are connected by the continuous baffle 11a, but the number of connected blades 10 can, of course, vary. Compared to separate baffles, this continuous baffle 11a is suitable for, for example, the production of grinding discs. Furthermore, the continuous baffle can strengthen the blades and improve the load distribution on the finishing mill.

[0045] In some embodiments of the invention and as such Figure 6 and Figures 7A-7CAs shown, each patterned region 41' can also include a series of final slurry stops 11b, which include, for example, at least four slurry stops 11 connecting at least five end teeth 10a of the patterned region 41'. As described above, the end teeth 10a are the teeth positioned closest to the second end 43b of the patterned region 41a. The series of final slurry stops 11b of multiple patterned regions 41' can be connected by, for example, Figure 7A The connecting slurry baffles 11b' shown are connected, and the resulting continuous final slurry baffles 11c are arranged substantially along the outer periphery 118b of the effective surface 1;1'. This essentially means that the distance of the slurry baffles 11 from the outer periphery 118b can vary slightly, for example... Figure 7A As shown. In Figure 6 As can be seen, the combined continuous final baffle 11c is arranged around the outer periphery 118b of the effective surface 1'. The combined continuous final baffle 11c may be suitable for some embodiments of the invention, for example, because it can provide a more robust and durable construction and can facilitate the production of the effective surface.

[0046] The different shapes of grinding discs 102; 102'; 102'' correspond to the different shapes of grinding discs in the context of grinding discs 102; 102''. Figures 7A-7C The effective surface 1' is shown in the diagram. Multiple such grinding discs 102; 102'; 102'' are combined onto the grinding disc to provide, for example, an effective surface 1'. Figure 6 The effective surface 1' is shown. Figure 7A The grinding disc 102 is in the form of a circular sector with a central opening. In this form of the grinding disc 102, there may only be space for one or more complete patterned regions 41' and the portions thereof. Conversely, if the patterned regions 41' remain complete, the grinding disc 102'; 102'' can alternatively have as Figure 7B and 7C Another form shown. Figure 7B In the grinding disc 102', four complete pattern areas 41' are set in each grinding disc 102', and Figure 7C The grinding disc 102'' contains twelve complete pattern areas 41'.

[0047] Besides about Figure 6 In addition to the arrangement shown in Figure 7, other arrangements of the slurry baffle 11 can be provided on the effective surface 1; 1'.

Claims

1. A grinding plate for a refiner (100) for refining lignocellulosic material, the grinding plate (30) having an active surface (1; 1') which, when used in a refiner, will face another grinding plate, wherein, The active surface (1; 1') comprises a pattern of blades (10) and grooves (20) arranged in a plurality of pattern areas (41; 41'), wherein the pattern areas (41; 41') are positioned side by side to each other to cover at least a portion of the active surface (1; 1'), wherein each of the pattern areas (41; 41') has a length I extending between a first end (43a) and a second end (43b) of the pattern area (41; 41') and a width w extending between two side edges (45a, 45b) both extending between the first and second ends (43a, 43b) of the pattern area (41; 41'), wherein the second end (43b) is arranged at an outer periphery (118b) of the active surface (1; 1') and the first end (43a) is arranged closer to a centre (C) of the grinding disc (30) than the second end (43b), and wherein the distance between the two side edges (45a, 45b) is smallest in the first end (43a) of the pattern area (41; 41') and increases towards the second end (43b) of the pattern area (41; 41'), and wherein each of the pattern areas (41; 41') is positioned on the active surface (1; 1') such that a centre line c of the pattern area (41; 41') positioned in the centre of the pattern area (41; 41') and extending from the first end (43a) to the second end (43b) of the pattern area (41; 41') is arranged at an angle p to a radius R of the grinding disc (30) passing through a centre position cp of the pattern area (41; 41'), the angle p being between 10°-60°, wherein at least some of the blades (10) extend in a direction between the two side edges (45a, 45b) of the pattern area (41; 41') in which the blades (10) are arranged, wherein at least 80% of the total number of blades (10) arranged within one pattern area (41; 41') extend only within the pattern area (41; 41'), Each pattern area (41') comprises a continuous last slurry barrier (lib) comprising at least four slurry barriers (11) connecting at least five end blades (10a) of the pattern area (41'), the end blades (10a) being the blades (10) positioned closest to the second end (43b) of the pattern area (41'), whereby the continuous last slurry barriers (lib) of a plurality of pattern areas (41') are connected, whereby the combined continuous last slurry barrier (lie) is arranged substantially along the outer periphery (118b) of the active surface (1; 1').

2. The millstone according to claim 1, characterized in that The size and extension direction of the blades (10) within each pattern area (41; 41') can vary freely within each pattern area.

3. The millstone according to claim 1 or 2, characterized in that At least 90% of the teeth (10) extending along a direction between the two side edges (45a, 45b) of the pattern area (41; 41') have a length which is at least 75% of the width w of the pattern area (41; 41') in which each respective tooth is located.

4. The millstone according to claim 1 or 2, characterized in that The pattern area (41; 41') is delimited in its second end (43b) by a portion s of the outer periphery (118b) of the active surface (1) which reaches between the two side edges (45a, 45b) of the pattern area (41), the length of said portion s corresponding to the arc length of a circular sector having a central angle comprised between 1°-15° in a circle with the outer periphery (118b) of the active surface (1; 1').

5. The millstone according to claim 1 or 2, characterized in that The pattern area (41; 41') is delimited in its second end (43b) by a portion s of the outer periphery (118b) of the active surface (1) which reaches between the two side edges (45a, 45b) of the pattern area (41), the length of said portion s corresponding to the arc length of a circular sector having a central angle comprised between 4°-12° in a circle with the outer periphery (118b) of the active surface (1; 1').

6. The millstone according to claim 1 or 2, characterized in that The centre line c of the pattern area (41; 41') is arranged at an angle p with the radius R of the grinding disc (30), said angle p being comprised between 20°-40°.

7. The millstone according to claim 1 or 2, characterized in that The teeth (10) each have a length, a thickness and a height, wherein the height extends in a perpendicular direction from the active surface, whereby the thickness (bw) of the teeth (10) within each pattern area (41; 41') will decrease towards the outer periphery (118b) of the active surface (1; 1').

8. The millstone according to claim 1 or 2, characterized in that, The distance (gw) between adjacent teeth (10) in the same pattern area (41; 41') will decrease towards the outer periphery (118b) of the active surface (1; 1').

9. The millstone according to claim 1 or 2, characterized in that, The angle b between the direction of extension of the length of each tooth (10) in the pattern area (41; 41') and the radius R of the grinding disc (30) passing through the midpoint of the tooth decreases on average towards the outer periphery (118b) of the active surface (1; 1').

10. The millstone according to claim 1 or 2, characterized in that, In a first portion of the pattern area (41; 41') extending from the first end (43a) and towards the second end (43b) of the pattern area (41; 41'), the teeth (10) do not extend all the way between the two side edges (45a, 45b), but leave open wedge-shaped areas (47) without teeth between adjacent pattern areas (41; 41').

11. The millstone according to claim 1 or 2, characterized in that In each pattern area (41; 41') there are at least three end teeth (10a) which are shorter than adjacent teeth (10) in a direction towards the first end (43a) of the pattern area (41; 41'), the end teeth (10a) being teeth positioned closest to the second end (43b) of the pattern area (41; 41'), whereby these end teeth (10a) each extend towards an outer periphery (118b) of the active surface (1; 1').

12. The millstone according to claim 1 or 2, characterized in that Pads (11) are provided on the active surface (1'), whereby each pad (11) extends between two adjacent teeth (10), wherein at least four pads (11) are positioned such that they together form a continuous pad (11a) provided along a smooth curve.

13. An abrasive segment for use in a millstone (30) according to any one of claims 1 to 12, wherein, The grinding sheet (2; 102; 102'; 102") comprises a part of the active surface (1; 1') of the grinding disc (30), wherein the grinding sheet (2; 102; 102'; 102") comprises a plurality of complete pattern areas (41; 41') and / or a plurality of parts of pattern areas (41; 41').

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