Refiner plate with pulp screen having curved sides

Abstract

This disclosure provides a grinding disc (1) for fine grinding of lignocellulosic materials. The grinding disc (1) has a surface comprising a plurality of cutting teeth (10) extending in a direction between the inner periphery (17b) and the outer periphery (17a) of the grinding disc (1). j ), and multiple paddle stops (11 i Each baffle is located in the corresponding pair of adjacent cutter teeth (10). k 10 K+1 The grinding disc (10) extends between the two sides. The grinding disc (11) of the fine grinding mill includes at least one slurry baffle (11). p ), the slurry baffle (11) p The grinding disc (1) includes a curved side (11c) facing the inner periphery (17b) of the grinding disc (1). The curved side (11c) has a concave curvature relative to the inner periphery (17b), thereby allowing the grinding disc (11) to be positioned within the grinding disc. p ) and corresponding pairs of adjacent cutting teeth (10 k 10 k+1 A circular portion is formed within the area (20) defined by the slurry. Additionally, at least one slurry baffle (11) p The grinding disc is a three-dimensional extended body. The circular portion generated by the concave curvature gives the grinding disc of the fine grinding mill more robustness. This disclosure also provides a fine grinding mill disc including such a fine grinding mill disc. This disclosure further provides a fine grinding mill having at least one such fine grinding mill disc.

Description

[0001] This application is a divisional application of the PCT international invention patent application filed by Valmet, Inc. on May 2, 2019, with application number 201980036651.7 (international application number PCT / SE2019 / 050388) entitled "Grinding disc of a fine grinding mill with a slurry baffle having a curved side". Technical Field

[0002] The proposed technology generally relates to a grinding disc for a grinding mill for refining lignocellulosic materials. More specifically, the invention relates to a grinding disc comprising blades and a baffle, a grinding disc comprising such grinding discs, and a grinding mill comprising a grinding disc equipped with grinding discs comprising blades and a baffle. Background Technology

[0003] For example, a common refining mill for lignocellulosic materials comprises two opposing rotating discs, between which the material is refined or defiberized. The pair of opposing rotating discs may specifically include a rotating disc called a rotor and a stationary disc called a stator. These discs, or at least one of them, are typically provided with grinding discs called refining mill blades, the purpose of which is to achieve more efficient refining of the material. Certain types of refining mill blades are provided with groups of guide teeth and baffles. The guide teeth are radially extending and protruding structures disposed on the effective surface of the grinding disc, i.e., the surface on which the material flows, and are primarily used to achieve efficient refining of lignocellulosic materials. Baffles are also protruding structures disposed on the effective surface of the refining mill blade, but they are typically not disposed in the radial direction. Instead, these baffles are disposed on the refining mill blade such that a particular baffle contacts or connects two adjacent guide teeth. That is, the baffle is disposed such that it crosses the direction connecting two adjacent guide teeth. This direction may be approximately orthogonal to the guide teeth, but may also be angular relative to the radial direction. The specific purpose of the baffle is to lift the material flowing in the region between the cutter teeth upwards toward the disc gap, which is defined as the gap between two opposing grinding discs, such as the disc gap between the rotor and stator, or the disc gap separating two opposing rotating discs. The material is ground or fiberized in the disc gap between the discs. In the common case where each cutter tooth is connected to one or more baffles, the natural result of the geometry is the creation of numerous partially enclosed or defined regions between adjacent cutter teeth. The majority of the grinding material will flow in these regions.

[0004] A specific problem associated with grinding discs in fine grinding mills equipped with cutting teeth and slurry baffles is that, as structures protruding from the surface of the grinding disc, the cutting teeth and slurry baffles wear down due to their abrasive contact with the material being ground. As a result, the efficiency of the grinding disc decreases over time, and replacement of the grinding disc is required to achieve satisfactory quality for materials such as slurries. The proposed technology aims to provide a mechanism that at least mitigates some of the problems associated with the wear experienced by grinding discs in fine grinding mills equipped with cutting teeth and slurry baffles. Summary of the Invention

[0005] The aim is to provide a grinding disc for a fine grinding mill that has improved robustness in resisting wear caused by material flow on the grinding disc.

[0006] The specific purpose is to provide a grinding disc for a fine grinding mill that has the feature of making the slurry baffle disposed on the grinding disc more elastic to resist wear caused by material flow.

[0007] Another objective is to provide a grinding disc comprising grinding mill discs that has improved elasticity to resist wear caused by material flow.

[0008] Another objective is to provide a fine grinding mill that includes a fine grinding disc with improved fine grinding mill discs.

[0009] These and other objectives are achieved through embodiments of the proposed technology.

[0010] According to a first aspect, a grinding disc for finely grinding lignocellulosic materials is provided. The grinding disc has a surface comprising: a plurality of cutting teeth extending along a direction between an inner periphery and an outer periphery of the grinding disc; and a plurality of baffles, each baffle extending between a corresponding pair of adjacent cutting teeth. At least one of the baffles is a three-dimensionally extending body comprising three sides extending between the corresponding pairs of adjacent cutting teeth, and includes curved sides forming one of the three sides facing the inner periphery of the grinding disc. The curved sides have a concave curvature relative to the inner periphery, thereby forming a circular portion in the region defined by the baffles and the corresponding pairs of adjacent cutting teeth.

[0011] According to a second aspect of the proposed technology, a fine grinding mill disc is provided, which includes fine grinding mill discs according to the first aspect.

[0012] According to a third aspect of the proposed technology, a fine grinding mill is provided, which includes a fine grinding mill disc according to the second aspect.

[0013] Embodiments of the proposed technology provide grinding discs for fine grinding mills, as well as corresponding grinding discs and fine grinding mills, which better withstand wear caused by abrasive contact between the slurry baffle and the material flowing on the grinding discs. This, in turn, extends the effective life of the grinding discs.

[0014] Other advantages will become apparent when you read the detailed implementation details. Attached Figure Description

[0015] The embodiments and their additional objects and advantages can be best understood by referring to the following description taken in conjunction with the accompanying drawings, in which: Figure 1 This is a schematic diagram of a fine grinding mill, in which grinding discs according to the proposed technology can be used.

[0016] Figure 2 It is a schematic diagram of the cross-section of a fine grinding mill disc arrangement, in which fine grinding mill discs according to the proposed technology can be used.

[0017] Figure 3 This is a schematic diagram of a known fine grinding mill disc as viewed from above.

[0018] Figure 4 This is a schematic diagram of a known grinding disc for a fine grinding mill, which is attached to a grinding mill disc such as a rotor disc or a stator disc.

[0019] Figure 5 This is a top view of a portion of the grinding disc of a fine grinding machine based on the proposed technology.

[0020] Figure 6 This is a top view schematic diagram of a specific embodiment of a fine grinding mill disc according to the proposed technology.

[0021] Figure 7 This is a schematic perspective view of a specific embodiment of a grinding mill disc according to the proposed technology.

[0022] Figure 8 yes Figure 7 The diagram shows a top view of a specific embodiment. Detailed Implementation

[0023] Throughout the accompanying drawings, the same reference numerals are used for similar or corresponding elements.

[0024] Generally, unless explicitly stated and / or implied from the context of use, all terms used herein shall be interpreted according to their ordinary meaning in the relevant art. Unless otherwise expressly stated, all references to an element, device, component, apparatus, step, etc., shall be interpreted as referring to at least one instance of that element, device, component, apparatus, step, etc. Unless explicitly described as a step following or preceding another step and / or implicitly described as a step that must follow or precede another step, the steps of any method disclosed herein need not be performed in the exact order disclosed. Where appropriate, any feature of any embodiment disclosed herein may be applied to any other embodiment. Similarly, any advantage of any embodiment may be applied to any other embodiment, and vice versa.

[0025] To better understand the proposed technology, it may be helpful to begin with a brief description of a typical fine grinding mill and a short analysis of the technical problems that the proposed technology aims to alleviate.

[0026] Therefore, refer to Figure 1 It schematically illustrates a fine grinding machine that can utilize the proposed technology. Figure 1 An exemplary pulp mill 100 is schematically shown in cross-sectional view. This arrangement is housed within a housing 26, which represents the outer casing of the mill assembly 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 mill disc 30 and the stator mill disc 30. Linear alignment along the axis. Rotor grinding mill disc 30 and stator grinding mill disc 30 Hereinafter referred to as the rotor and stator, respectively. The rotor 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 and thus the rotor 30. The stator 30 faces the rotor 30. A centrally located through-hole 32 may be provided, extending between the feed channel 14 for the lignocellulosic material and the finishing zone 19. In some embodiments, the rotor 30 may be provided with a center plate 17, the surface of which faces the inflow of the lignocellulosic material. The surface of the center plate 17 may be provided with a structure to guide the lignocellulosic material outward. Rotor 30 And / or the stator 30 is provided with grinding mill discs to allow the slurry to be turned and ground. These grinding mill discs may be provided with blades and baffles.

[0027] During use, wood fiber materials, such as wood chips or prepared wood, such as pulp, are fed through feed channel 14 by means of a feed mechanism (not shown). The material will pass through stator 30. The hole 32 in the middle enters region 19. Region 19 is basically composed of rotor 30 and stator 30. The open area between them is defined, and this area can be very small during operation. The lignocellulosic material in the inflow area 19 will be incident on the center plate 17 on the rotor 30. The center plate 17 serves to guide the lignocellulosic material toward the grinding discs on the rotor and / or stator.

[0028] To provide a more detailed description of the rotor-stator arrangement in which the proposed technology can be used, refer to Figure 2 . Figure 2 A side sectional view of a rotor-stator arrangement housed in a casing 31 of, for example, a fine grinding mill as described above is shown. The rotor is shown arranged to rotate about a rotation axis. A fine grinding disc 30, including fine grinding mill grinding discs 1, is provided on the surface of the rotor facing the stator. The rotor is provided on the surface of the rotor facing the stator, including fine grinding mill grinding discs 1. 30 fine grinding mill disc In some forms of fine grinding mills, the mill disc can be referred to as a grinding disc holder because one of the purposes of the mill disc is to support the fine grinding discs 1 and 1. Also in Figure 7 The image shows an inlet 32 ​​for the lignocellulosic material undergoing fine grinding. Inlet 32 ​​is located in the central region of the stator. A center plate 17 is arranged opposite to inlet 32 ​​in the central region of the grinding disc on the rotor side. (Already referenced above...) Figure 1 The purpose of the center plate 17 described is to distribute the material falling from the inlet 32 ​​toward the outer section of the grinding mill disc. That is, the center plate 17 serves to distribute the material toward the grinding mill discs arranged on the grinding mill disc.

[0029] Having already described in detail a general-purpose fine grinding mill capable of utilizing the proposed technology, we will now proceed to describe in detail specific known fine grinding mill discs related to the proposed technology. For this purpose, refer to... Figure 3 . Figure 3A schematic diagram of a grinding disc 1 for a fine grinding mill is provided. In this particular example, the grinding disc 1 includes circular sectors. Other forms of grinding discs for fine grinding mills exist, but the proposed technique is equally effective for all specific shapes of grinding discs for fine grinding mills. The grinding disc 1 is configured as the shape of the disc to be attached to the grinding disc 30 for fine grinding mills. The grinding disc for fine grinding mills can be configured as a circular shape, optionally having a removed central region, or as a circular sector shape. The grinding disc 30 can therefore be provided with a plurality of grinding discs 1, thereby being completely or partially covered by the grinding discs 1. The grinding discs for fine grinding mills can specifically form a rotor disc or a portion thereof equivalent to a rotor grinding disc. In the case where the grinding disc 1 forms a portion of a rotor grinding disc, the central region of the rotor grinding disc may include a center plate. Figure 3 A grinding disc for a fine grinding mill is shown, having an inner periphery 17b and an outer periphery 17a. The inner periphery 17b is the outer edge of the grinding disc and is designed to be closest to the center of the grinding mill disk 30 when the grinding disc has been attached. The grinding disc also has a plurality of radially extending cutter teeth 10 that travel in a nearly parallel manner along the effective surface of the grinding disc, i.e., the surface facing the material flow. A plurality of slurry baffles 11 orthogonally guided relative to the cutter teeth 10 are also shown, wherein each slurry baffle 11 is connected to two cutter teeth 10 in a pair of adjacent cutter teeth 10. The arrangement of the cutter teeth and slurry baffles defines a partially defined portion 20.

[0030] Figure 4 yes Figure 3 A simplified view of a portion of the grinding disc 1 in the figure. In this particular drawing, the grinding disc 1 is attached to a circular grinding disc 30, such as a stator or rotor, having a center C. The radial direction is indicated by arrow R. The radial direction extends from the center of the disc toward the periphery of the disc, passing through the inner periphery 17b and outer periphery 17a of the grinding disc. The schematic diagram shows in detail two sets of adjacent and adjacent cutting teeth 10, 10 Each tooth in a group of adjacent cutting teeth is protected by a baffle 11, 11 and 11 They are interconnected. The radial extension of the baffle relative to the cutter teeth extends between adjacent cutter teeth in an approximately orthogonal direction. Thus, by the adjacent cutter teeth 10, 10 The corresponding baffle 11 creates, thus defining, a partially open area 20. During the use of the grinding disc, the majority of the material will flow in such areas. As previously mentioned, as the material flows toward the periphery of the grinding disc, it impacts the baffle and is lifted toward the disc gap. The interaction between the flowing material and the baffle will cause significant wear on the baffle and may eventually destroy at least part of it, thereby reducing the efficiency of the grinding disc because the expected material lifting effect will be partially lost. The purpose of the proposed technique is to provide a mechanism that improves the resilience of the grinding disc to resist wear caused by the abrasive contact between the material flow and the baffle.

[0031] The proposed technology provides a grinding disc 1 for refining lignocellulosic materials. The grinding disc 1 has a surface comprising a plurality of cutting teeth 10 extending along a direction between the inner periphery 17b and the outer periphery 17a of the grinding disc 1. j and multiple paddle stops 11 i Each slurry stop is located in a corresponding pair of adjacent cutter teeth 10 k 10 k+i Extending between. Paddle stop 11 p At least one of them is a three-dimensionally extended body comprising three sides. The three-dimensionally extended body is located in the corresponding pair of adjacent cutting teeth 10 k 10 k+1 Extending between and including a curved side 11c, which forms one of the three sides and faces the inner periphery 17b of the grinding disc 1. The curved side 11c has a concave curvature relative to the inner periphery 17b, that is, it has a concave curvature when viewed from the periphery 17b, thereby affecting the shape of the grinding disc 11. p and corresponding pairs of adjacent cutting teeth 10 k 10 k+1 The circular portion is formed within the defined region 20.

[0032] The proposed grinding disc for a fine grinding mill has a slurry baffle structure, wherein the slurry baffle is configured as a three-dimensionally extended body comprising three sides, one of which, i.e., the side facing the incoming material, is curved or rounded relative to the periphery 17b. That is, when viewed from the periphery 17b, it is curved in a concave manner, which can, for example... Figure 5 , 6 As seen in Figure 7, the features of this fine grinding disc ensure that a large amount of additional material is used to construct the slurry baffle, which provides additional protection against abrasion. The slurry baffle also has rounded sides adapted to face the incoming material, thus ensuring reduced wear when the abrasive material comes into contact with the slurry baffle.

[0033] Taking these features into account, the baffle is made very robust to resist wear caused by the interaction between the flowing material and the baffle.

[0034] A three-dimensionally extended slurry baffle 11 is set on the fine grinding surface of the fine grinding mill disc. p And it can be provided in various shapes, such as a three-dimensional wedge or block shape, wherein one of the sides, the side facing the incoming material, is curved or rounded. Figure 7 The image shows this three-dimensional extended paddle stop 11 p The curved side facing the incoming material is designated 11c. In a direction perpendicular to the grinding surface of the grinding disc, the slurry baffle also has a side opposite to the curved side and an upward-facing side.

[0035] Figure 5 An example of a portion of a grinding disc 1 for finely grinding lignocellulosic materials is provided. The grinding disc 1 has a surface comprising a plurality of cutting teeth 10 extending in a direction between the inner periphery 17b and the outer periphery 17a of the grinding disc 1. j The surface also includes multiple baffles 11 i , i = 1, 2, ..., p, p+1, ... N, where each slurry stop is in the corresponding pair of adjacent cutter teeth 10 k 10 k+i Extending between. At least one slurry baffle 11 on the grinding disc 1 of the fine grinding mill. p This includes a curved side 11c facing the inner peripheral edge 17b of the grinding disc 1. The curved side 11c has a concave curvature relative to the inner peripheral edge 17b, thereby... p and corresponding pairs of adjacent cutting teeth 10 k 10 k+1 The defined area 20 forms a circular portion. (See detailed description) Figure 5 Previously, we briefly explained the reference numerals used in the figures. The proposed technique provides a fine grinding mill disc comprising multiple slurry baffles. For example, the total number of slurry baffles can be represented as N. Reference numeral 11 i The index i used iterates through all integers from 1 to N, i.e., i = 1, 2, ..., p, p+1, ..., N. Therefore, specific paddles are indicated by the reference numerals 111, 112, ..., 11. p The proposed technology also provides a grinding disc for a fine grinding machine that includes multiple cutting teeth. The total number of cutting teeth can be denoted as M, for example, where M can be equal to N, but generally not. (The last part, "10," appears to be an unrelated instruction and is left untranslated.) j The index used iterates through all integers from 1 to M, i.e., i = 1, 2, ..., k, k+1, ..., M. Therefore, a specific blade tooth can be represented by the reference numerals 101, 102, ..., 10. kWaiting for the marker. Return to Figure 5 The figure shows a highly simplified top view of the arrangement of blades and baffles on a fine grinding mill disc according to the proposed technology. Figure 5 The image shows two radially extending cutter teeth 10. k and 10 k+1 Specific slurry blocks 11 extending between p Paddle stop 11 p Includes a curved side portion 11c, which has a concave curvature relative to the inner periphery 17b of the grinding disc 1. This concave curvature is formed by the paired cutting teeth 10. k ;10 k+1 Mixing and blocking 11 p A circular portion is generated within the defined area 20. The inventors have discovered that this is achieved by the paddle block 11. p The rounded portion obtained by the curved side 11c makes the grinding disc of the fine grinding mill less prone to wear caused by the material flowing through region 20.

[0036] Some embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. However, other embodiments are included within the scope of the subject matter disclosed herein, and the disclosed subject matter should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided by way of example only to convey the scope of the subject matter to those skilled in the art.

[0037] A specific embodiment of the proposed technology provides a grinding disc 1 for a fine grinding mill, wherein the first end 11c1 of the curved side 11c is connected to the cutting teeth 10 in a radial position. k The radial position is such that the second end 11c2 of the curved side 11c is connected to the adjacent cutting tooth 10. k+1 The radial position is closer to the inner periphery 17b of the grinding disc 1 of the fine grinding machine, thus forming a circular part with rounded corners. Figure 6 A top schematic and simplified view of a single cutter tooth and slurry baffle arrangement according to this particular embodiment are provided. This embodiment specifically provides a fine grinding mill disc 1, wherein, relative to the intended direction of rotation of the fine grinding mill disc, the first end 11c1 of the slurry baffle is the rear end, and the second end 11c2 of the slurry baffle is the front end. The fine grinding mill disc with this arrangement functions to ensure that the main portion of the material flow on the fine grinding mill disc 1 primarily contacts the circular portion of the slurry baffle as the fine grinding mill disc 1 rotates. Since the circular portion better withstands wear caused by interaction with the material, a more robust fine grinding mill disc is obtained.

[0038] Another embodiment of the proposed technology provides a fine grinding mill disc 1, wherein the slurry baffle includes a three-dimensionally extended body, and the curved side 11c of the slurry baffle includes an outer surface of the three-dimensionally extended body facing the inner periphery of the grinding mill disc. A particular form of this embodiment provides a fine grinding mill disc 1, wherein at least one slurry baffle 11p In the corresponding pairs of adjacent cutting teeth 10 k 10 k+i The three sides of the body extend between them, and the curved side 11c forms one side of the three sides of the body. Figure 7 A perspective view of such an embodiment is provided. A three-dimensionally extended first paddle stop 11 is shown. p How to use two adjacent cutting teeth 10 k and 10 k+1 The teeth extend between the inner and outer circumferences 17b and 17a. In this example, the teeth extend along the total distance between the inner and outer circumferences 17b and 17a; however, there are embodiments in which they only extend a portion of the distance between the inner and outer circumferences 17b and 17a. The first end 11c1 of the paddle stop is arranged closer to the inner circumference of the paddle stop than the opposing second end 11c2. In this example, the second end 11c2 is the front end in the indicated intended rotational direction, while the first end 11c1 is the rear end. The first paddle stop 11 extends in three dimensions. p One side includes a curved side 11c facing the inner periphery 17b of the grinding wheel. When viewed from the inner periphery 17b, this curved side 11c has a concave curvature. The slurry baffle with the curved side shown forms a rounded corner in region 20, which is configured such that when the grinding wheel rotates in the direction indicated by the arrow, i.e., counterclockwise, it faces most of the material flow. Pairs of adjacent cutting teeth 10 k and 10 k+1 It also includes an additional slurry baffle 11 that serves the same purpose but is positioned closer to the inner perimeter 17b. p+1 . Figure 8 An illustration of this embodiment is also provided, but when viewed from above. Figure 8 The first end 11c1 of the curved side 11c of the three-sided body is shown to connect to the cutter tooth 10 in a radial position. k The second end 11c2 of the radially positioned, curved side 11c, is connected to the adjacent cutting tooth 10. k+1 The radial position is closer to the inner periphery 17b of the grinding disc 1 of the fine grinding machine, thereby forming a rounded portion in the partially defined area 20.

[0039] Another embodiment of the proposed technology provides a fine grinding mill disc 10, wherein each pair of adjacent cutting teeth 10 k 10 k+1 Includes multiple paddle stops 11 p Each slurry baffle has curved sides, wherein each slurry baffle 11 p Along the adjacent teeth 10 k 10 k+1 They are arranged at different radial positions. Figure 5-8 A schematic diagram of such an embodiment is provided. Figures 5 to 8The simplified diagram shows two paddle stops 11, each with a curved side 11c. p and 11 p+1 How to achieve the following at different radial positions with adjacent cutter teeth 10 k 10 k+1 Extending between. Different radial positions can be defined, for example, with respect to the inner periphery 17b of the grinding disc of a fine grinding mill. Wherein, a particular pair of adjacent cutting teeth 10 k 10 k+1 Including several slurry baffles 11p, 11 p+1 11 p+2 ...the grinding discs of the fine grinding mill will produce corresponding pairs of adjacent cutting teeth 10 k 10 k+1 And several separate areas 20 defined by the slurry baffle. For example, in Figure 5 The diagram shows how to pass through adjacent cutter teeth 10 k 10 k+1 Mixing and blocking 11 p 11 p+1 To define region 20. It also shows how to use adjacent cutting teeth 10. k 10 k+1 Mixing and blocking 11 p+1 To limit the area to 20 Area 20 It can end at the inner periphery 17b of the grinding disc of the fine grinding mill, but it can also be terminated by an additional slurry baffle 11 (not shown). p+2 The region 20 can thus be defined by a single baffle and two adjacent cutter teeth to have an open channel toward the inner periphery 17b or the outer periphery 17a, but it can also be defined by two baffles and two adjacent cutter teeth to form a box-shaped region 20. However, this region is open in the upward direction so as to be able to lift the material flow toward the disc gap defined as the gap between two relatively rotating grinding discs. According to a specific embodiment of the proposed technology, this embodiment relates to the case where region 20 is defined by adjacent cutter teeth 10 k 10 k+1 and slurry baffles 11 arranged at different radial positions p 11 p+1 Defined in the radial direction, the relative distance D between the first end 11c1 and the second end 11c2 of the curved side 11c can be, for example, a paddle stop 11. p Mixing and blocking 11 p+1 The length of the region 20 between them is 1-30%. More preferably, in the slurry stop 11 p Mixing and blocking 11 p+1 The region between 20 and 10% of its length. This is within... Figure 5 As shown in the image.

[0040] It should be noted that all slurry baffles on the grinding mill disc can be provided in the curved form proposed in this disclosure, but it is also possible to provide only a subset of slurry baffles having this feature. A specific example is provided by the grinding mill disc 1, wherein at least the radially intermediate section of the grinding mill disc 1 is equipped with a slurry baffle 11 having a curved side 11c. p This embodiment provides a grinding disc for a fine grinding mill, wherein a slurry baffle disposed in the central band of the disc has curved sides to provide additional resistance to wear, at least in the effective area of ​​the grinding disc. The radially intermediate section or central band of the grinding disc may, for example, be defined relative to the inner periphery 17b of the grinding disc.

[0041] According to an additional aspect of the proposed technology, a grinding disc 1 for a fine grinding mill is provided, which is attached to a circular grinding disc 30 of a fine grinding mill such that the curved side 11c faces the center of the circular grinding disc 30 and has a concave curvature relative to the center C of the grinding disc, so that the circular portion faces the material flow guided from the center C of the grinding disc toward the periphery of the grinding disc 30. The grinding disc 30 may be, in particular, a rotor disc or a stator disc.

[0042] According to another aspect of the proposed technology, a fine grinding mill 100 for fine grinding lignocellulosic materials is provided, the fine grinding mill including at least one fine grinding mill disc 30, the fine grinding mill disc 30 including fine grinding mill blades 1 as previously described.

[0043] The embodiments described above are given by way of example only, and it should be understood that the proposed technology is not limited thereto. Those skilled in the art will understand that various modifications, combinations, and changes can be made to the embodiments without departing from the scope defined by the appended claims. Specifically, different component schemes in different embodiments can be combined in other constructions, as long as it is technically feasible.

Claims

1. A grinding disc (1) for finely grinding lignocellulosic materials, the grinding disc (1) having a surface comprising: Multiple cutting teeth (10) j The cutting teeth extend radially along the direction between the inner periphery (17b) and the outer periphery (17a) of the grinding disc (1); and a plurality of slurry baffles (11) i Each of the aforementioned baffles is located in a corresponding pair of adjacent blades (10) k 10 K+1 The grinding disc (1) of the fine grinding mill extends between the two sides, characterized in that the slurry baffle (11) extends between the two sides. p At least one of them is a three-dimensionally extended body comprising three sides, the three-dimensionally extended body being in the corresponding pair of adjacent cutting teeth (10) k 10 k+1 Extending between the three sides and including curved sides (11c), the curved sides forming one of the three sides facing the inner periphery (17b) of the grinding disc (1), the curved sides (11c) having a concave curvature relative to the inner periphery (17b), thereby extending between the three sides facing the inner periphery (17b) of the grinding disc (11). p ) and the corresponding pairs of adjacent cutting teeth (10 k 10 k+1 A circular portion is formed in the area (20) defined by the three-dimensional extension, wherein the three-dimensional extension body has a three-dimensional wedge-shaped or block-shaped shape, which is formed in the slurry baffle (11). p ) connected to a pair of adjacent cutting teeth (10 k 10 k+1 The radial thickness of one of the blade teeth in the ) is greater than that of the slurry baffle (11). p ) connected to a pair of adjacent cutting teeth (10 k 10 k+1 The radial thickness at another cutting tooth in the ).

2. The grinding disc (1) of the fine grinding mill according to claim 1, characterized in that, The first end (11c1) of the curved side (11c) is connected to the cutting tooth (10) in a radial position. k The second end (11c2) of the radially positioned portion (11c) is connected to the adjacent cutting tooth (10). k+1 The radial position of the grinding disc (1) is closer to the inner periphery (17b) of the grinding disc (1), thus forming a rounded portion.

3. The grinding disc (1) of the fine grinding mill according to claim 2, characterized in that, Relative to the intended rotation direction of the grinding disc of the fine grinding mill, the first end (11c1) is the rear end, and the second end (11c2) is the front end.

4. The grinding disc (1) of the fine grinding mill according to any one of claims 1 to 3, characterized in that, Each pair of adjacent cutting teeth (10) k 10 k+1 ) includes multiple paddle stops (11 p Each grout stop has curved sides, wherein each grout stop (11) p ) along the paired adjacent cutting teeth (10 k 10 k +1 They are arranged at different radial positions.

5. The grinding disc (1) of the fine grinding mill according to any one of claims 1 to 4, characterized in that, At least the radially intermediate section of the grinding disc (1) of the fine grinding mill is equipped with a slurry baffle (11) having a curved side (11c). p ).

6. The grinding disc (1) of the fine grinding mill according to any one of claims 1 to 5, characterized in that, The grinding disc (1) of the fine grinding mill is attached to the circular grinding mill disc (30) of the fine grinding mill such that the curved side (11c) faces the center of the circular grinding mill disc (30) and has a concave curvature relative to the center (C) of the grinding mill disc, such that the circular portion faces the material flow guided from the center (C) of the grinding mill disc toward the periphery (P) of the grinding mill disc (30).

7. A grinding mill disc (30) comprising the grinding mill disc (1) according to claim 6.

8. The grinding mill disc (30) according to claim 7, characterized in that, The grinding mill disc (30) is a rotor disc or a stator disc.

9. A fine grinding mill (100) for finely grinding lignocellulosic materials, characterized in that, The grinding mill includes a grinding mill disc (30) according to claim 7 or 8.

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