Blade for a refiner for refining lignocellulosic material and refiner comprising at least one blade

Abstract

This invention relates to a blade for a fine grinding mill for fine grinding lignocellulosic materials. The blade (10) is defined by an inner periphery (11) and an outer periphery (12) and includes a blade surface (13) having a fine grinding portion (14). A plurality of fine grinding mill teeth (20) are arranged on the fine grinding portion (14), wherein each fine grinding mill tooth (20) extends from an outer tooth tip (21) to an inner tooth tip (22), and wherein the plurality of fine grinding mill teeth (20) are arranged such that along the tooth extension from the fine grinding mill tooth... The movement of the outer tooth tip (21) to the inner tooth tip (22) of the tooth (20) is also a movement along the first circumferential direction (D), and wherein the blade (10) further includes at least one baffle (30) extending from the outer baffle tip (31) to the inner baffle tip (32) and connecting at least three grinding mill teeth (20), and wherein, further, the baffle (30) is arranged such that the movement along the baffle from the outer baffle tip (31) to the inner baffle tip (32) is also a movement along the first circumferential direction (D). The invention also relates to a grinding mill including at least one such blade.

Description

Technical Field

[0001] This invention relates to blades for a fine mill used for fine grinding lignocellulosic materials during pulp production, and also to such a fine mill. Background Technology

[0002] Disc mills are commonly used in the pulp industry to refine lignocellulosic materials used in the production of fibrous materials such as paper and board.

[0003] A disc grinder comprises two or more opposing grinding elements, at least one of which is rotatable. The rotating grinding element may be referred to as a rotor or rotor-side blade, while the non-rotating or stationary grinding element may be referred to as a stator or stator-side blade. Between the grinding elements is a grinding gap through which the material to be ground is abraded against grinding surfaces. The grinding surfaces of the grinding elements include grinding bars that serve as grinding tools for grinding lignocellulosic materials during use, and dams that intersect with the grinding bars and lift the lignocellulosic material toward the grinding gap to ensure thorough grinding.

[0004] Refining lignocellulosic materials is costly because the energy consumption to achieve the desired fiber quality is typically very high. While some improvements have been suggested in this area, further development is needed to ensure the required fiber quality while providing more energy-efficient refining mill blades. Summary of the Invention

[0005] The object of the present invention is to eliminate or at least minimize the aforementioned problems. This is achieved by blades for a fine grinding mill and a fine grinding mill comprising such blades as described below.

[0006] The blade according to the invention is defined by an inner periphery and an outer periphery, and includes a blade surface having a fine-grinding portion on which a plurality of fine-grinding cutter teeth are arranged. Each fine-grinding cutter tooth extends from an inner cutter tooth end to an outer cutter tooth end, and the plurality of fine-grinding cutter teeth are angled such that movement along the bar extension from the outer cutter tooth end to the inner cutter tooth end is also movement in a first circumferential direction. Furthermore, the blade includes at least one dam, which extends from an inner dam end to an outer dam end and connects at least three fine-grinding cutter teeth, wherein the dam is angled such that movement along the dam extension from the outer dam end to the inner dam end is also movement in a first circumferential direction.

[0007] Therefore, the paddle baffle is arranged to effectively elevate the lignocellulosic material into the grinding gap while minimizing flow restriction, thereby reducing energy consumption during operation. This, in turn, allows the paddle baffle to feed the lignocellulosic material along the blade to the outer periphery, ensuring the desired grinding quality while reducing wear and energy consumption, as the paddle baffle obstructs material flow less than known prior art solutions.

[0008] According to some embodiments, the height of at least one slurry baffle is substantially equal to the height of at least one of the cutting teeth intersecting the slurry baffle. This ensures that the slurry baffle can lift the lignocellulosic material into the finishing gap to improve the finishing quality.

[0009] According to other embodiments, the height of at least one slurry baffle is 20% to 99%, preferably 20% to 85%, of the height of at least one of the grinding mill teeth to which the slurry baffle is connected. This achieves a subsurface slurry baffle that allows steam flow and also improves material flow across the slurry baffle.

[0010] In some embodiments, the blade includes a blade with a baffle height substantially equal to the tooth height, and further includes at least one blade with a baffle height of 20% to 99%, preferably 20% to 85%, of the tooth height of at least one of the fine grinding mill teeth to which the baffle is connected. Therefore, the baffle and the subsurface baffle can be combined as needed to improve the flow of lignocellulosic material and steam while achieving high-quality fine grinding.

[0011] Suitable for use, the blades also include grooves extending adjacent to the slurry baffle on the outer peripheral side of the baffle. This enables the pumping and conveying of lignocellulosic material, which, after passing the slurry baffle, can flow along the grooves between the grinding mill blades before entering them, for further conveying towards the outer periphery. This, in turn, improves energy efficiency and reduces wear on the grinding mill blades.

[0012] The width of the groove can increase toward the end of the inner pulp stop. Thus, as the lignocellulose material passes along the groove, it is forced into the toothed groove.

[0013] Furthermore, the width of the groove at the upper end is appropriately at least equal to the width of the slurry baffle. Therefore, the groove is wide enough to improve the flow of the lignocellulosic material. The width at the upper end is the distance from the outer side of the slurry baffle in the radial direction to the point where the grinding mill cutter teeth begin to taper towards the blade surface.

[0014] Appropriately, the depth of the groove is at least equal to half the height of the slurry baffle adjacent to the groove. Therefore, the groove is deep enough to improve the flow of the lignocellulosic material.

[0015] Appropriately, the blade also includes a reinforcing portion at which the end of the outer blade guard connects to the grinding mill teeth, the reinforcing portion being arranged on the side of the blade guard facing the inner periphery. This reduces wear and consequently increases blade life.

[0016] Furthermore, the outer end of the first baffle and the inner end of the second baffle can each be connected to the same blade, and the inner end of the second baffle is closer to the inner periphery than the outer end of the first baffle. This avoids grooves not crossed by the baffles, preventing the lignocellulosic material from flowing across the blades without being lifted into the grinding gap. Additionally, the baffles are angled or curved to improve the transport of the lignocellulosic material.

[0017] Appropriately, the outer end of the first blade and the outer ends of the adjacent blades in the radial direction are each connected to different grinding mill teeth in the first circumferential direction. Therefore, the blades overlap in the radial direction, which increases the blade's strength and distributes the area subjected to high wear across the entire blade, making the blade more robust as a whole.

[0018] In some embodiments, the blade is a blade portion having a center angle of 10° to 360°. Where the blade is not circular, the blade portion may be combined with multiple similar or identical blade portions to form a circular blade.

[0019] Furthermore, there may be at least one section lacking the teeth of a fine grinding mill. Therefore, unless it is in the fine grinding section, the lignocellulosic material can be transported across the blades without being finely ground.

[0020] The present invention also relates to a grinding mill for fine grinding of lignocellulosic materials, comprising at least one blade according to any embodiment of the present invention.

[0021] Many additional benefits and advantages of the present invention will be readily understood by those skilled in the art in light of the detailed description below. Attached Figure Description

[0022] The invention will now be described in more detail with reference to the accompanying drawings, in which: Figure 1a A top plan view of a blade according to a first embodiment of the present invention is disclosed; Figure 1b A top plan view of a blade according to a second embodiment of the present invention is disclosed; Figure 2a A top plan view of a blade according to a third embodiment of the present invention is disclosed; Figure 2b A top plan view of a blade according to a fourth embodiment of the present invention is disclosed; Figure 3aA top plan view of a blade according to a fifth embodiment of the present invention is disclosed; Figure 3b It was made public. Figure 3a An enlarged view of one of the slurry blocks; Figure 3c A top plan view of a blade according to a sixth embodiment of the present invention is disclosed; Figure 4 A top view of an embodiment showing different densities of grinding mill cutter teeth in each group of grinding mill cutter teeth is shown. Figure 5 A top plan view of an embodiment with an outer portion is shown; Figure 6 A top plan view of an embodiment without grooves is shown; Figure 7a A schematic diagram showing the view from the side of the groove has been published; and Figure 7b Another schematic diagram showing the view from the side of the groove has been released.

[0023] All figures are schematic and not necessarily drawn to scale. They generally show only the parts necessary to illustrate the various embodiments, while other parts may be omitted or only implied. Unless otherwise indicated, any reference numerals appearing in multiple figures refer to the same object or feature in the figures. Detailed Implementation

[0024] Figure 1a A blade 10 according to a first embodiment of the present invention is disclosed. The blade 10 shown in the figures according to any embodiment of the present invention may be a portion of a circular blade, only a portion of which is shown, or alternatively may be a leaf segment configured to be mounted together with a plurality of similar leaf segments to form a circular blade.

[0025] In use, blades 10 are typically mounted in a disc grinder (not shown) and are used to grind lignocellulosic material by acting as blades within a pair of blades arranged facing each other, wherein at least one blade in the pair is arranged to rotate. Generally, the blades arranged to rotate in the disc grinder are called rotor-side blades, while the blades arranged to be stationary are called stator-side blades. In use, a grinding gap is formed between the blades such that the lignocellulosic material passing through the grinding gap is ground by the grinding mill teeth arranged on each blade.

[0026] As used herein, the term "lignocellulosic material" refers to a material that contains cellulose and preferably also contains lignin and hemicellulose. An example of such a material is wood; other examples include other agricultural or forestry waste. When lignocellulosic material is ground in a disc grinder, the material is typically fed into the grinder through an opening at the center of one of the blades and ground while moving radially outward between the blade pairs. Lignocellulosic material can also refer to materials that primarily contain cellulose, such as cotton.

[0027] The invention will be described with reference to various embodiments, and it should be particularly noted that features from one embodiment can be freely incorporated into another embodiment unless such combination is explicitly stated to be unsuitable or undesirable. Therefore, the embodiments disclosed herein can be combined with each other as needed.

[0028] It should be noted that each embodiment shown in the figures may be only a part of the blade 10, and the blade 10 itself may include additional portions at the inner periphery 11, the outer periphery 12, and each side shown in each figure. Therefore, these figures will be considered as embodiments having patterns of grinding mill teeth and slurry baffles that can be repeated across the entire blade 10 or can be provided in only a portion of the blade 10.

[0029] Figure 1a The blade 10 shown is defined by an inner periphery 11 and an outer periphery 12, and includes a blade surface 13. On the blade surface 13 is at least one fine-grinding portion 14, which includes a plurality of fine-grinding machine teeth 20 extending outwardly from the blade surface 13. The fine-grinding portion 14 may extend across the entire blade surface 13, but in most embodiments, the blade surface 13 also includes other portions that do not contain the fine-grinding machine teeth 20. Figure 1a In the illustration, the blade 10 shown lacks the grinding mill teeth 20 in the portion near the inner periphery 11. The grinding mill teeth 20 can also be positioned near the outer periphery 12 or in other portions of the blade surface 13.

[0030] Each of the grinding mill cutter teeth 20 includes an outer cutter tooth end 21 and an inner cutter tooth end 22, wherein the outer cutter tooth end 21 is closer to the outer periphery 12 than the inner cutter tooth end 22. The grinding mill cutter teeth 20 are arranged such that movement along the tooth extension, i.e., movement along a single grinding mill cutter tooth 20 from the outer cutter tooth end 21 to the inner cutter tooth end 22, is also movement along a first circumferential direction D. When the blade 10 is arranged in the grinding mill, the first circumferential direction D is the direction of rotation, and the first direction of rotation D is further perpendicular to the radial direction R, which is defined as the direction from a point on the inner periphery 11 to the point on the outer periphery 12 closest to that point on the inner periphery 11. Movement along the tooth extension is movement along the first circumferential direction D, which should be understood herein as movement having a component oriented along the first circumferential direction D. A component in the radial direction perpendicular to the first circumferential direction D may also exist.

[0031] The arrangement of the grinding mill teeth 20 means that they are inclined relative to the radial direction R to form a tooth angle α of less than 90 degrees in the clockwise direction. In some embodiments, the grinding mill teeth 20 are parallel to each other, but in other embodiments, at least one of them may not be parallel to the other grinding mill teeth. Furthermore, in some embodiments, the grinding mill teeth form straight lines, but in some embodiments, the grinding mill teeth may be curved. Furthermore, in some embodiments, the grinding mill teeth 20 may vary across the blade 10, such that some of them form straight lines while others are curved, and some of them are parallel while others are not. At the inner tooth tip 22, the teeth 20 preferably taper towards the blade surface 13. The tooth angle α of each grinding mill tooth 20 may be different, but advantageously in the range of 5° to 60°.

[0032] The fine grinding section 14 is also provided with at least one slurry stop 30 connecting at least three fine grinding mill teeth 20. Each slurry stop 30 extends from an outer slurry stop end 31 to an inner slurry stop end 32, wherein the outer slurry stop end 31 is closer to the outer periphery 12 than the inner slurry stop end 32. The slurry stops 30 are further arranged such that movement along the slurry stop extension, i.e., movement along a single slurry stop 30 from the outer slurry stop end 31 to the inner slurry stop end 32, is also movement along a first circumferential direction D. This means that the slurry stops 30 are inclined relative to the radial direction R to form a slurry stop angle β of less than 90° in the clockwise direction. The slurry stop angle β of each slurry stop 30 may be different, but advantageously is in the range of 30° to 85°. In embodiments where the slurry stops 30 are bent, the slurry stop angle β is appropriately reduced when moving from the outer slurry stop end 31 toward the inner slurry stop end 32.

[0033] With the slurry baffle 30 connected to the grinding mill cutter teeth 20, a connection angle γ is formed at the corner facing the first circumferential direction D and the inner periphery 11. The connection angle γ is advantageously in the range of 30° to 85°, which ensures efficient grinding of lignocellulosic materials and reduces energy consumption.

[0034] Preferably, the cutter tooth angle α can vary across segments. Advantageously, a larger cutter tooth angle α is provided towards the center of the blade 10, i.e., towards the inner periphery 11, but a smaller cutter tooth angle is provided when the cutter teeth are closer to the outer periphery 12. Furthermore, the baffle angle β can vary across segments, and advantageously, a smaller baffle angle β is provided near the inner periphery 11, while a larger baffle angle β is provided near the outer periphery 12. Therefore, when moving radially across the blade 10 from the inner periphery 11 to the outer periphery 12, the cutter tooth angle α preferably decreases, while the baffle angle β increases.

[0035] In the first embodiment, the fine grinding section 14 includes a plurality of slurry baffles 30 arranged in this manner; however, in other embodiments, a single slurry baffle 30 may alternatively be provided. Furthermore, Figure 1a The slurry baffles 30 shown are configured such that groups of grinding mill teeth 20 are connected by more than one slurry baffle 30, which are arranged along the same grinding mill teeth 20 but at different distances from the inner periphery 11. In other embodiments, the slurry baffles 30 may alternatively be arranged such that only some of the grinding mill teeth 20 connected by one slurry baffle 30 are connected by another slurry baffle 30 closer to the inner periphery 11, or each grinding mill tooth 20 may be connected to only one slurry baffle 30.

[0036] In addition, Figure 1a In one embodiment, all the grinding mill teeth 20 are connected to the grinding mill teeth 20 located at the inner slurry end 32 of one slurry stop 30 via at least one slurry stop 30, which is also located at the outer slurry end 31 of another slurry stop 30. In other embodiments, some grinding mill teeth 20 may not be connected to any slurry stop 30, or the positioning of the slurry stop 30 may be varied on the grinding section 14 as needed.

[0037] The baffles 30 can also form straight lines or curves, and they can be parallel or non-parallel to each other as needed.

[0038] The fact that the inner blade end 22 and inner pulp stop end 32 of the blade 20 and pulp stop 30 are positioned further forward along the first axial direction D than the outer blade end 21 and outer pulp stop end 31 means that the pulp stop 30 can lift the lignocellulose material from the blade groove 40 into the grinding gap to improve grinding, while also allowing the lignocellulose material to be effectively transported from the inner periphery 11 across the blade 10 to the outer periphery 12. This further reduces energy consumption because the pulp stop 30 provides less obstruction to the flow of lignocellulose material than a pulp stop 30 arranged at an angle greater than 90° to the radial direction R; that is, the outer pulp stop end of the pulp stop is further inclined along the first circumferential direction D.

[0039] exist Figure 1a In one embodiment, the height of at least one baffle 30 is substantially equal to the height of the tooth of at least one blade 20 to which the baffle 30 intersects. This means that the baffle 30 lifts the cellulose material all the way to the finishing gap and prevents lignocellulosic material not finished by the finishing mill blade 20 from crossing the baffle 30. "Substantially equal to the blade height" should be understood as meaning they are equal within manufacturing tolerances, or at least the difference between them does not exceed 10% of their height from the blade surface 13. In the first embodiment, all baffles 30 have this baffle height, but in other embodiments, at least one of them may be lower. A baffle height substantially equal to the blade height is also advantageous in increasing the pressure between the blades during finishing.

[0040] Figure 1b A second embodiment is disclosed, which differs from the first embodiment in that at least one baffle 30 is a subsurface baffle, i.e., the baffle height is less than the tooth height of at least one polishing mill cutter 20 connected to the baffle 30. In the second embodiment, the baffle height is 20% to 99%, preferably 20% to 85%, of the tooth height of at least one of the polishing mill cutters connected to the baffle 30. When using the blade 10 according to the invention, this has the advantage of promoting steam flow in the opposite direction to the flow direction of the lignocellulose material, because the baffle 30 provides less obstruction to the flow in the cutter groove 40. At the same time, the polishing efficiency remains very close to that of the first embodiment described above, because most of the lignocellulose material will be lifted into the polishing gap, while the high-pressure steam, which normally moves along the cutter groove 40, will move freely and is allowed to enter the cutter groove 40 on the outer side 34 of the baffle 30. Figure 1b In the second embodiment, all the slurry baffles 30 are subsurface slurry baffles, but in other embodiments, some of them may have, for example, […]. Figure 1a The full tooth height is shown. In some embodiments, the lower surface baffle is particularly advantageous for the outer periphery 12 where steam backflow occurs.

[0041] Figure 2aA third embodiment of the blade 10 is disclosed, which differs from the first and second embodiments in that it includes a groove 50 extending adjacent to the paddle baffle 30 on the outer side 34 of the paddle baffle 30, i.e., on the side of the paddle baffle 30 facing the outer periphery 12. The groove 50 extends along the paddle baffle 30 and is long enough to pass through at least three grinding mill teeth 20. In some embodiments, the groove 50 extends along the entire paddle baffle 30, i.e., from the inner paddle baffle end 32 to the outer paddle baffle end 31. The groove 50 is defined by the outer side 34 of the paddle baffle 30 and the grinding mill teeth 20 located at positions where the grinding mill teeth 20 begin to taper toward the blade surface 13. Figures 2a to 2b (As shown by the dashed line).

[0042] The groove 50 can be viewed as an interruption to the grinding mill teeth 20, which extend from the outer tooth tip 21 and taper at the groove 50 to the blade surface 13, then continue from the paddle stop 30 toward the inner tooth tip 22. Alternatively, the groove 50 can be viewed as providing an end to the grinding mill teeth 20 that tapers toward the blade surface 13, thus forming their inner tooth tips 22. In the third embodiment, the groove 50 is provided for all paddle stops 30, but in other embodiments, some paddle stops 30 may not have the groove 50.

[0043] The advantage of groove 50 is that it allows for the pumping and conveying of lignocellulosic material across blade 10 during use. This means that as blade 10 rotates in the first circumferential direction D, the lignocellulosic material travels in one of the toothed grooves 40 to the pulp stop 30, is then lifted into the finishing gap, and travels along groove 50 before entering another toothed groove 40. This... Figure 2a The image is shown with a dashed arrow. This conveying method increases the energy efficiency of the grinding mill and reduces wear on the blades 10, ensuring a longer service life.

[0044] The width of the groove 50 increases from the outer pulp baffle end 31 toward the inner pulp baffle end 32, thereby facilitating the lignocellulosic material to enter the tooth groove 40 as it moves along the groove 50. The groove 50 further has a groove width at its upper end, i.e., at the end furthest from the blade surface 13, that is, a groove width at least equal to the upper width of the pulp baffle 30. The groove width should also be understood as the width in the radial direction R from the pulp baffle 30 to the grinding mill tooth 20 on the outer side 34 of the pulp baffle 30. At the upper end of the groove 50, the grinding mill tooth 20 is at its full height, but the grinding mill tooth 20 appropriately tapers toward the outer side 34 of the pulp baffle 30 to reduce wear.

[0045] Figure 2bA fourth embodiment of the blade 10 is disclosed, which is similar to the third embodiment in that it includes a groove 50 on the outer side 34 of the baffle 30, but is also similar to the second embodiment in that at least some of the baffles 30 are subsurface baffles. The pumping and conveying of lignocellulosic material is further improved by the subsurface baffles 30, which facilitate passage over the baffles 30 to allow steam flow, thereby reducing energy consumption and wear on the baffles 30. The conveying of the lignocellulosic material is shown as a dashed arrow, similar to... Figure 2a .

[0046] Figure 3a A fifth embodiment of the blade 10 is disclosed, wherein the grinding mill teeth 20 on one side of the groove 50 are not extensions of the grinding mill teeth 20 on the other side of the groove 50, but are arranged to be different from each other in direction or inclination. The density of the grinding mill teeth 20, i.e., how many grinding mill teeth 20 are provided on a surface portion of a given size, can also be different.

[0047] Furthermore, the fifth embodiment includes a reinforcing portion 33 on at least one slurry baffle 30, arranged at the location where the outer slurry baffle end 31 connects to the finishing mill blade 20. The reinforcing portion 33 is arranged on the side of the slurry baffle 30 facing the inner periphery 11, i.e., on the side opposite the outer periphery 34. More specifically, the reinforcing portion 33 is arranged at the corner of the slurry baffle 30 where it meets the last finishing mill blade 20 at the outer slurry baffle end 31. The reinforcing portion 33 is thus arranged where the wear of the lignocellulosic material on the slurry baffle 30 is particularly high, and therefore serves to protect the slurry baffle 30 and extend the life of the blade 10. Suitablely, the reinforcing portion 33 is integral with the slurry baffle 30 and the finishing mill blade 20, but in some embodiments, it may be a separate portion added during manufacturing at the outer slurry baffle end 31 at the corner between the slurry baffle 30 and the finishing mill blade 20.

[0048] In a fifth embodiment, at least one of the slurry baffles 30 further includes a reinforcing portion 33 at one or more intersection points of the slurry baffle 30 and the grinding mill teeth 20, which is particularly advantageous in reducing wear on the slurry baffle 30 overall. Other embodiments may include the reinforcing portion 33 only at the outer slurry baffle end 31.

[0049] Figure 3b According to Figure 3a An enlarged view of the blade 10 and the blade baffle 30, wherein the reinforcing portion 33 is provided at each intersection between the blade baffle 30 and one of the grinding mill teeth 20, more specifically, at the corners facing the first circumferential direction D at these intersections, because these corners are the corners that wear the most due to the rotation of the blade 10 during use.

[0050] Figure 3cA sixth embodiment similar to the fifth embodiment is disclosed, except that at least some of the slurry baffles 30 are subsurface slurry baffles 30. The reinforcing portion 33 of the fifth embodiment may be included at at least one intersection point between the slurry baffle 30 and one of the grinding mill teeth 20, preferably at least at the end 31 of the outer slurry baffle. However, the reinforcing portion 33 is not shown in... Figure 3c middle.

[0051] exist Figure 3a and Figure 3c In this embodiment, the outer end 31 of the first baffle 30 and the inner end 32' of the second baffle 30' are connected to the same grinding mill blade 20. The inner end 32' of the second baffle 30' is closer to the inner periphery 11 than the outer end 31 of the first baffle 30. This ensures that the transport of lignocellulose material across the blade 10 is efficient and energy-efficient.

[0052] exist Figures 3a to 3c In one embodiment, in the radial direction perpendicular to the first circumferential direction D, the outer end 31 of the first baffle 30 and the outer end 31'' of the adjacent baffle 30'' are each connected to different polishing mill teeth 20. This means that there is overlap of the baffles 30, 30'' along the first circumferential direction D at the outer end 31, 31''. In other words, the outer end 31 of the first baffle 30 is offset from the outer end 31'' of the adjacent baffle 30'' along the first circumferential direction D. The advantage of this arrangement is that the flow of lignocellulose material and steam will cause wear on the baffles 30, 30'', especially at the outer end 31, 31'', and by distributing the outer end 31, 31'' in this way, the wear on the blades is also greater than when the outer end 31 of multiple baffles 30 are connected to the same polishing mill tooth 20 or connected to polishing mill teeth that are extended from each other (e.g., see...). Figure 2a In the embodiments of ), the distribution is more uniform.

[0053] Figure 4 One embodiment is disclosed, wherein the density of the grinding mill teeth 20 in each set of grinding mill teeth is different from the inner periphery 11 to the outer periphery 12. Furthermore, the slurry baffle 30 is shown as a subsurface slurry baffle 30, and a groove 50 is provided on the outer side 34 of each slurry baffle 30.

[0054] Figure 5 An embodiment with an outer portion 15 is disclosed, which is disposed on the blade surface 13, between the fine grinding portion 14 and the outer periphery 12. In the outer portion 15, fine grinding mill teeth and a slurry baffle are provided for further fine grinding of the lignocellulosic material after it has been passed through the fine grinding portion 14 with the fine grinding mill teeth 20 and slurry baffle 30 arranged according to the invention.

[0055] As described above, blade 10 can be a circular blade, but alternatively it can be a blade portion with a center angle of 10° to 360°. Then, multiple blade portions can be installed in a fine grinding mill to form a circular blade.

[0056] The finely ground portion 14 can extend from the inner periphery 11 across the entire blade surface 13 to the outer periphery 12. Alternatively, other portions may be present on the blade surface 13, such as those described above. Figure 5 The outer portion 15 disclosed herein may also exist. A portion may include grinding mill teeth arranged between the grinding portion 14 and the inner periphery 11. Furthermore, at least one portion on the blade surface 13 may be without grinding mill teeth, and such a portion may be arranged near the inner periphery 11, near the outer periphery 12, or at any other portion of the blade surface. Additionally, in some embodiments, there may be two or more grinding portions 14 according to the invention on the blade surface 13, while another portion includes grinding mill teeth or has no grinding mill teeth between them.

[0057] Figure 6 An embodiment of the invention is disclosed, which does not have a groove 50, and the angle of the grinding mill teeth 20 varies across the blade 10.

[0058] Figure 7a A groove 50 adjacent to the slurry baffle 30 is shown. The groove width w of the groove 50 is at least the width of the adjacent slurry baffle 30, but can be significantly larger. Furthermore, the depth d of the groove 50 is at least half the slurry baffle height of the adjacent slurry baffle 30. Figure 7a In this design, the width of the groove 50 is equal to the width of the adjacent slurry baffle 30, and the depth d is equal to half the height of the slurry baffle 30. The depth d of the groove 50 is described with respect to the adjacent fine grinding mill cutter tooth 20, that is, the fine grinding mill cutter tooth 20 that begins to taper at the groove 50. Therefore, the depth d is the depth from the upper end of the adjacent fine grinding mill cutter tooth 20, while the slurry baffle height is the height from the groove 40 of the cutter tooth adjacent to the slurry baffle 30. Figure 7b A groove 50 is disclosed, wherein the groove width w is greater than the width of the slurry baffle 30, and the depth is equal to the slurry baffle height of the slurry baffle 30. In other embodiments, the dimensions of the groove 50 may be varied such that the groove width is equal to the depth, or alternatively, the groove width and depth may differ from each other in any suitable manner, as long as they are greater than [the required value]. Figure 7a The minimum size shown is sufficient.

[0059] The present invention also relates to a fine grinding mill comprising at least one blade 10 according to any embodiment of the invention disclosed herein. In some embodiments, the fine grinding mill may include two blades 10 according to the invention, one blade being arranged as a rotor-side blade and the other as a stator-side blade. In other embodiments, a blade 10 according to the invention may be arranged as a rotor-side blade or a stator-side blade together with a fine grinding mill blade according to the prior art.

[0060] It should be noted that the features from the various embodiments described herein can be freely combined unless it is explicitly stated that such a combination would be inappropriate.

Claims

1. A blade for a fine grinding mill, the fine grinding mill being used for fine grinding lignocellulosic materials, the blade (10) being defined by an inner periphery (11) and an outer periphery (12), and including a blade surface (13) having a fine grinding portion (14), on which a plurality of fine grinding mill teeth (20) are arranged, wherein, Each grinding mill tooth (20) extends from the outer tooth end (21) to the inner tooth end (22), and wherein the plurality of grinding mill teeth (20) are arranged such that the movement along the tooth extension from the outer tooth end (21) to the inner tooth end (22) of the grinding mill tooth (20) is also a movement along a first circumferential direction (D), and wherein the blade (10) further includes at least one baffle (30) extending from the outer baffle end (31) to the inner baffle end (32). It connects at least three grinding mill teeth (20), and wherein the slurry baffle (30) is further arranged such that the movement along the slurry baffle from the outer slurry baffle end (31) to the inner slurry baffle end (32) is also the movement along the first circumferential direction (D), and also includes a groove (50) extending along the slurry baffle (30) and adjacent to the slurry baffle (30) on the outer side (34), the outer side (34) being the side facing the outer periphery (12).

2. The blade according to claim 1, characterized in that, The height of the at least one slurry baffle (30) is substantially equal to the height of at least one of the fine grinding mill teeth (20) to which the slurry baffle (30) intersects.

3. The blade according to claim 1, characterized in that, The height of the at least one slurry baffle (30) is 20% to 99% of the height of at least one of the fine grinding mill cutter teeth (20) to which the slurry baffle (30) is connected.

4. The blade according to claim 3, characterized in that, The height of the at least one slurry baffle (30) is 20% to 85% of the height of at least one of the fine grinding mill cutter teeth (20) to which the slurry baffle (30) is connected.

5. The blade according to claim 2, characterized in that, The blade also includes at least one blade (30) whose blade height is 20% to 99% of the height of at least one of the grinding mill teeth (20) to which the blade is connected.

6. The blade according to claim 5, characterized in that, The blade also includes at least one blade (30) whose blade height is 20% to 85% of the height of at least one of the grinding mill teeth (20) to which the blade is connected.

7. The blade according to claim 1, characterized in that, The width of the groove (50) increases toward the inner slurry end (32).

8. The blade according to claim 1 or 7, characterized in that, The width of the groove (50) at its upper end is at least equal to the width of the paddle stop (30).

9. The blade according to claim 1 or 7, characterized in that, The depth (d) of the groove (50) is at least equal to half the height of the slurry baffle (30) adjacent to the groove (50), and the depth (d) is the depth from the upper end of the adjacent fine grinding mill tooth (20).

10. The blade according to any one of claims 1 to 6, characterized in that, It also includes a reinforcing portion (33), the end of the outer slurry baffle (31) being connected to the grinding mill tooth (20) at the reinforcing portion, the reinforcing portion (33) being arranged on the side of the slurry baffle (30) facing the inner periphery.

11. The blade according to any one of claims 1 to 6, characterized in that, The outer end (31) of the first baffle (30) and the inner end (32') of the second baffle (30') are each connected to the same grinding mill tooth (20), and wherein the inner end (32') of the second baffle (30') is closer to the inner periphery (11) than the outer end (31) of the first baffle (30).

12. The blade according to any one of claims 1 to 6, characterized in that, The outer end (31) of the first slurry stop (30) and the outer end (31'') of the adjacent slurry stop (30'') in the radial direction are each connected to different precision grinding mill teeth (20) in the first circumferential direction (D).

13. The blade according to any one of claims 1 to 6, characterized in that, The blade (10) is a blade portion having a center angle of 10° to 360°.

14. The blade according to any one of claims 1 to 6, characterized in that, It also includes at least one part that lacks the cutting teeth of a fine grinding mill.

15. A grinding mill for finely grinding lignocellulosic materials, said grinding mill comprising at least one blade according to any one of claims 1 to 14.

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