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

Abstract

A blade for a refiner for refining lignocellulosic material is provided, the blade comprising a blade surface configured to face another blade of the refiner and having a refining portion, the refining portion comprising a plurality of knives and a plurality of slurry bars, each slurry bar extending between two adjacent knives of the plurality of knives, wherein the plurality of slurry bars comprises a first slurry bar extending along a first slurry bar axis and a second slurry bar extending along a second slurry bar axis, wherein the first slurry bar axis deviates from the second slurry bar axis in a direction along a first knife axis, wherein the first knife comprises a knife section extending between the first slurry bar axis and the second slurry bar axis, wherein a width of the knife section in a width direction perpendicular to the first knife axis is greater than a width of a remainder of the first knife outside the knife section in the width direction.

Description

Blades for a fine grinding mill for refining lignocellulosic materials and a fine grinding mill including at least one blade. Technical Field

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

[0002] Fine grinding mills, or disc mills, are commonly used in the pulp industry to finely grind 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. Furthermore, refining mill blades wear down during use and must be replaced periodically, ranging from several days to several months depending on the lignocellulosic material and its condition. The refining mill is offline during blade replacement, making this process inefficient and costly. Summary of the Invention

[0005] One of the objectives of this disclosure is to eliminate or at least reduce the aforementioned problems. This is achieved through blades used in a fine grinding mill and a fine grinding mill comprising such blades as described below.

[0006] In this disclosure, according to a first aspect, a blade for a fine grinding mill is provided for fine grinding lignocellulosic materials. The blade includes a blade surface configured to face another blade of the fine grinding mill and defined by an inner periphery and an outer periphery. The blade surface has a fine grinding portion comprising: a plurality of cutting teeth projecting from the blade surface, wherein each of the plurality of cutting teeth extends at least partially along a corresponding cutting tooth axis of the plurality of cutting tooth axes, wherein each corresponding cutting tooth axis extends from the inner periphery toward the outer periphery, wherein the plurality of cutting teeth includes a first cutting tooth extending along a first cutting tooth axis of the plurality of cutting tooth axes; and a plurality of baffles, each baffle extending along a corresponding baffle axis of the plurality of baffle axes and extending between two adjacent cutting teeth, wherein the plurality of baffles includes a first baffle extending along a first baffle axis and a baffle extending along a first baffle axis. A second baffle extending from the axis of a first baffle is offset from the axis of a second baffle in a direction along the axis of a first cutter tooth. The first baffle extends laterally from a first side of the first cutter tooth to a first adjacent cutter tooth among a plurality of cutter teeth. The second baffle extends laterally from a second side of the first cutter tooth opposite to the first side to a second adjacent cutter tooth among a plurality of cutter teeth. The first baffle is closest to the outer periphery among one or more baffles extending from the first cutter tooth to the first adjacent cutter tooth. The second baffle is closest to the outer periphery among one or more baffles extending from the first cutter tooth to the second adjacent cutter tooth. The first cutter tooth includes a cutter tooth section extending between the axis of the first baffle and the axis of the second baffle. The width of the cutter tooth section in a width direction perpendicular to the axis of the first cutter tooth is greater than the width of the remaining portion of the first cutter tooth outside the cutter tooth section in that width direction.

[0007] The blade disclosed in this patent includes a toothed section located between a first and a second impeller, which is thicker than the rest of the blade. This toothed section forms the boundary between the high pressure inside the grinding mill and the low pressure outside. It has been found that thickening the toothed section advantageously extends the blade's lifespan, while having little or no impact on grinding performance.

[0008] In one embodiment, the plurality of cutting teeth includes one or more groups of cutting teeth, each group of cutting teeth including a first cutting tooth, a first adjacent cutting tooth, and a second adjacent cutting tooth.

[0009] In one embodiment, a plurality of blades and a plurality of baffles are disposed in a plurality of patterned regions, wherein the patterned regions are positioned side by side to cover at least a portion of the blade surface. The patterned regions may have different orientations. The corresponding orientation of the blade axis and / or baffle axis of the first patterned region may be different from the corresponding orientation of the blade axis and / or baffle axis of the second patterned region adjacent to the first patterned region.

[0010] In one embodiment, each patterned area includes one or more blades from one or more sets of blades.

[0011] In one embodiment, multiple sets of cutting teeth overlap each other, such that the first adjacent cutting tooth of the first cutting tooth set in one or more cutting tooth sets is also the first cutting tooth of the second cutting tooth set in one or more cutting tooth sets.

[0012] In one embodiment, the first adjacent cutter tooth of the first cutter tooth group in one or more cutter tooth groups is also the second adjacent cutter tooth of the second cutter tooth group in one or more cutter tooth groups.

[0013] In one embodiment, the second adjacent cutter of the first cutter group in one or more cutter groups is also the first cutter of the second cutter group in one or more cutter groups.

[0014] In one embodiment, the second adjacent cutter of the first cutter group in one or more cutter groups is also the first adjacent cutter of the second cutter group in one or more cutter groups.

[0015] In one embodiment, the first cutter of the first cutter group in one or more cutter groups is also the first adjacent cutter of the second cutter group in one or more cutter groups.

[0016] In one embodiment, the first cutter of the first cutter group in one or more cutter groups is also the second adjacent cutter of the second cutter group in one or more cutter groups.

[0017] In one embodiment, the multiple cutting teeth include multiple sets of cutting teeth, with the sets of cutting teeth adjacent to each other.

[0018] In one embodiment, the plurality of patterned regions include: a first patterned region of cutting teeth and a slurry baffle; a second patterned region of cutting teeth and a slurry baffle, wherein the orientation of the second patterned region differs from that of the first patterned region, wherein the first and second patterned regions are positioned side-by-side relative to each other to cover at least a portion of the finishing section; and one or more connecting cutting teeth and / or connecting slurry baffles connecting corresponding cutting teeth and / or slurry baffles of the first and second patterned regions, wherein the cutting teeth group of the first patterned region may not overlap with the cutting teeth group of the second patterned region. In other words, a widened cutting tooth segment is included within the patterned region. The widened cutting tooth segment may not be the segment connecting the two patterned regions.

[0019] In one embodiment, the plurality of cutting teeth are arranged such that movement along the axes of the plurality of cutting teeth from the outer periphery to the inner periphery is also movement along a first circumferential direction. When the blades are used in a finishing mill during finishing, this causes the lignocellulose material to be pushed outward toward the outer periphery.

[0020] In one embodiment, a plurality of baffles are arranged such that movement along the respective baffle axes of the plurality of baffles from the inner periphery to the outer periphery is also movement along a first circumferential direction, the plurality of baffle axes including a first baffle axis and a second baffle axis.

[0021] In one embodiment, a plurality of baffles are arranged such that movement along the respective baffle axes of the plurality of baffles from the outer periphery to the inner periphery is also movement along a first circumferential direction, the plurality of baffle axes including a first baffle axis and a second baffle axis.

[0022] In one embodiment, the first baffle is closer to the outer periphery than the second baffle.

[0023] In one embodiment, the second baffle is closer to the outer periphery than the first baffle.

[0024] In one embodiment, the cutting tooth segment includes a first lateral edge and a second lateral edge opposite to the first lateral edge, wherein the first lateral edge is at least partially offset relative to the first cutting tooth axis compared to a corresponding lateral edge of the remainder of the first cutting tooth; or, the second lateral edge is at least partially offset relative to the first cutting tooth axis compared to a corresponding second lateral edge of the remainder of the first cutting tooth.

[0025] In one embodiment, a first slurry baffle extends from a first lateral edge; a second slurry baffle extends from a second lateral edge; the second slurry baffle is closer to the outer periphery than the first slurry baffle when the first lateral edge is offset; and the first slurry baffle is closer to the outer periphery than the second slurry baffle when the second lateral edge is offset.

[0026] In one embodiment, the serrated section has a triangular shape when viewed from a direction perpendicular to the blade.

[0027] In one embodiment, the toothed section includes an inner end closest to the inner periphery and an outer end closest to the outer periphery, wherein the width of the toothed section at the inner end is greater than the width of the toothed section at the outer end.

[0028] In one embodiment, the serrated section has a rectangular shape when viewed from a direction perpendicular to the blade.

[0029] In one embodiment, when viewed from a direction perpendicular to the blade, the tooth section has one of the following shapes: angled shape, concave arc shape, convex arc shape, concave shape, and convex shape.

[0030] In one embodiment, each of the plurality of tooth axes does not intersect with another tooth axis of the plurality of tooth axes within the finishing section.

[0031] In one embodiment, each of the plurality of tooth axes does not intersect with another tooth axis of the plurality of tooth axes within the finishing section.

[0032] According to some embodiments, the height of each slurry baffle is substantially equal to the tooth height of at least one cutting tooth to which the slurry baffles intersect. This ensures that the slurry baffles can lift the lignocellulosic material into the finishing gap to improve the finishing quality.

[0033] According to other embodiments, the height of each slurry baffle is 20% to 99%, preferably 20% to 85%, of the height of at least one of the grinding 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.

[0034] 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.

[0035] Suitablely, the blades may 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, whereby the material, after passing the slurry baffle, can flow along the grooves between the grinding mill blades before entering them, for further conveying towards the outer peripheral side. This, in turn, improves energy efficiency and reduces wear on the grinding mill blades.

[0036] 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.

[0037] Furthermore, the width of the groove at the upper end can be 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 along the radial direction to the point where the grinding mill cutter teeth begin to taper towards the blade surface.

[0038] Appropriately, the depth of the groove can be 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.

[0039] Suitable for use, the blade may also include 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, thereby further increasing blade life.

[0040] Appropriately, the outer end of the first blade and the outer ends of adjacent blades in the radial direction can each be 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 blade, making the blade more robust overall.

[0041] 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.

[0042] 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.

[0043] According to a second aspect, a fine grinding mill is provided, comprising at least one blade according to any one or more embodiments of the blades described above and / or below in the first aspect.

[0044] Given the detailed description below, many additional benefits and advantages disclosed in this patent will be readily understood by those skilled in the art. Attached Figure Description

[0045] The patent disclosure will now be described in more detail with reference to the accompanying drawings, in which:

[0046] Figure 1 is a cross-sectional schematic diagram of a fine grinding mill, in which a fine grinding mill disc according to the present patent can be used;

[0047] Figure 2 is a top plan view of a blade according to an embodiment disclosed in this patent;

[0048] Figure 3 is a top plan view of a set of blade teeth according to an embodiment of this patent.

[0049] Figure 4 is a top plan view of a set of blade teeth according to an embodiment of this patent.

[0050] Figure 5 is a top plan view of two sets of overlapping blade teeth according to an embodiment of the present patent.

[0051] Figure 6 is a top plan view of a set of blade teeth according to an embodiment of this patent.

[0052] Figure 7 is a top plan view of a set of blade teeth according to an embodiment of this patent.

[0053] Figure 8 is a top plan view of a set of blade teeth according to an embodiment of the present patent.

[0054] Figure 9 is a top plan view of a set of blade teeth according to an embodiment of this patent.

[0055] Figure 10 is a top plan view of a set of blade teeth according to an embodiment of the present patent.

[0056] Figure 11 is a top plan view of a set of blade teeth according to an embodiment of the present patent.

[0057] Figure 12 is a top plan view of a set of blade teeth according to an embodiment of the present patent.

[0058] Figure 13 is a top plan view of a set of blade teeth according to an embodiment of this patent; and

[0059] Figure 14 is a top plan view of a blade according to another embodiment disclosed in this patent.

[0060] All accompanying drawings are schematic and not necessarily to scale, and generally only show parts that help to illustrate the various embodiments, while other parts may be omitted or only implied. Unless otherwise indicated, any reference numerals appearing in multiple drawings refer to the same object or feature in the drawing. Detailed Implementation

[0061] Referring to Figure 1, a fine grinding mill disclosed in this patent is schematically shown. Figure 1 schematically shows a cross-sectional view of the pulp fine grinding mill 1. Examples of components not shown are an electric motor for driving, for example, a rotating shaft, a feeding mechanism for lignocellulosic material, etc. Rotor fine grinding mill disc 36 and stator fine grinding mill disc 36 Linear alignment along an axis (not shown). The rotor grinding mill disc 36 can be attached to a rotating shaft arranged on bearings. The rotating shaft can be connected to a motor (not shown) that rotates the shaft, thereby rotating the rotor grinding mill disc 36. Stator grinding mill disc 36 facing the rotor grinding mill disc 36. A centrally located through-hole 38 may be provided, extending between the feed channel for lignocellulosic material and the grinding zone 19. Feeding material into the grinding zone 19 does not necessarily require a centrally located through-hole as shown in FIG. 1, but can be done via through-holes distributed in a manner different from central positioning. In some embodiments, the rotor grinding disc 36 may be provided with a center plate 16 having a surface facing the inflow of lignocellulosic material. The surface of the center plate 16 may have a structure for guiding the lignocellulosic material outward. Rotor grinding disc 36 and / or stator grinding disc 36 Blades 10 are provided to achieve slurry direction and grinding. These blades 10 may be equipped with cutting teeth and slurry baffles, which will be described in more detail below. In some fine grinding mills, there may be two rotor fine grinding discs instead of rotor fine grinding discs and stator fine grinding discs, wherein the two rotor fine grinding discs rotate in opposite directions. This patent disclosure can also be applied to such fine grinding mills.

[0062] During use, lignocellulosic materials such as wood chips or pre-made wood (e.g., pulp) are fed through the feed channel by a feeding mechanism, such as a screw feeder (not shown). The material passes through the stator grinding mill disc 36. The through-hole 38 leads into region 19. Region 19 is essentially composed of the rotor and stator grinding disc 36. 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 16 on the rotor grinding disc 36. The center plate 16 serves to guide the lignocellulosic material toward the blades 10 on the rotor and / or stator grinding disc.

[0063] 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 refined, it can also refer to a material primarily containing cellulose, such as cotton.

[0064] Rotor grinding mill disc 36 facing stator grinding mill disc 36 At least one blade 10 is provided on the surface of the stator. Stator grinding mill disc 36 At least one blade 10 is also provided on the surface facing the rotor grinding mill disk 36. These blades are respectively provided on the rotor grinding mill disk 36 and the stator grinding mill disk 36. The blades 10 on the rotor can be designed identically or differently. The grinding mill blades disclosed in this patent can be provided to the rotor grinding mill disc 36 and the stator grinding mill disc 36. One or both of them, or in the case of two rotating disks, can be provided to one or both of the two rotor grinding disks. The rotor and stator grinding disks can be referred to as segment holders in certain patterned grinding mills, since one of the purposes of the grinding disks is to support the blades 10.

[0065] The general-purpose grinding mill 1 disclosed in the patent has been described above with reference to Figure 1. Figure 2 provides a schematic diagram of an example of the blade 10 according to the present patent disclosure. The blade 10 will be provided to the grinding mill disc. This can be a rotor grinding mill disc 36 and a stator grinding mill disc 36. Both, but will be referred to simply as a grinding mill disc below. In this particular example, the blade 10 consists of circular sectors. Other types of grinding mill blades exist; however, this patent disclosure is equally effective for all specific grinding mill blade shapes. The blade 10 is configured as a segment to be attached to the grinding mill disc. As described above, the blade 10 can be configured as a circular shape, optionally having a removed central region to leave space for the center plate 16 or through-hole 38. The blade 10 can also be configured as a circular sector shape, wherein the circle optionally has a removed central region or is configured as another part of the circle. Thus, the grinding mill disc can be provided with multiple blades 10, thereby being completely or partially covered by the blades 10. In the case where the blade 10 forms part of the rotor grinding mill disc, the central region of the rotor grinding mill disc may include the center plate 16 as described above.

[0066] Figure 2 shows a blade 10 according to a first embodiment disclosed in this patent. The blade 10 shown in the figures according to any embodiment disclosed in this patent 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.

[0067] As described above, in use, blades 10 are typically mounted in a disc grinder, such as a grinder 1, 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.

[0068] This patent discloses various embodiments, and it should be noted in particular that features from one embodiment can be freely incorporated into another embodiment unless such combination is explicitly stated to be inappropriate or undesirable. Therefore, the embodiments disclosed herein can be combined with each other as needed.

[0069] 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 and on each side shown in each figure. Therefore, these figures should be considered as embodiments having patterns that can be repeated throughout the entire blade 10 or may be provided in only a portion of the blade 10 for grinding mill teeth and slurry baffles.

[0070] The blade 10 shown in Figure 2 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 finely ground portion 14, which includes a plurality of cutting teeth 20 extending outwardly from the blade surface 13. The finely ground 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 plurality of cutting teeth 20. In Figure 2, the blade 10 shown lacks the plurality of cutting teeth 20 in the portion near the inner periphery 11; the plurality of cutting teeth 20 may also be provided in other portions of the blade surface 13.

[0071] Each of the plurality of cutting teeth 20 includes an outer cutting tooth end 21 and an inner cutting tooth end 22, wherein the outer cutting tooth end 21 is closer to the outer periphery 12 than the inner cutting tooth end 22. The plurality of cutting teeth 20 are arranged such that movement along the bar extension, i.e., movement along one of the plurality of cutting teeth 20 from the outer cutting tooth end 21 to the inner cutting 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 bar extension is movement along the first circumferential direction D and should be understood herein as movement having a component directed along the first circumferential direction D. A component in the radial direction perpendicular to the first circumferential direction D may also exist.

[0072] Each of the plurality of cutting teeth 20 extends at least partially along a corresponding cutting tooth axis of the plurality of cutting tooth axes (FIG. 3). Each corresponding cutting tooth axis extends from the inner periphery 11 toward the outer periphery 12. The plurality of cutting teeth 20 includes a first cutting tooth 23 extending along a first cutting tooth axis 230 of the plurality of cutting tooth axes, a first adjacent cutting tooth 24 or a second cutting tooth extending along a second cutting tooth axis 240, and a second adjacent cutting tooth 25 or a third cutting tooth extending along a third cutting tooth axis 250.

[0073] Each baffle extends along a corresponding baffle axis among a plurality of baffle axes and between two adjacent cutter teeth among a plurality of cutter teeth 20. The plurality of baffles 30 includes a first baffle 41 extending along a first baffle axis 410 and a second baffle 42 extending along a second baffle axis 420, wherein the first baffle axis 410 is offset from the second baffle axis 420 by an offset 421 along the direction of the first cutter tooth axis 230. The first baffle 41 extends from a first lateral side 28 of the first cutter tooth 23 to a first adjacent cutter tooth 24 or a second cutter tooth. The second baffle 42 extends from a second lateral side 29 of the first cutter tooth 23 opposite to the first lateral side 28 to a second adjacent cutter tooth 25 or a third cutter tooth.

[0074] In one or more cutter stops 30 extending from the first cutter tooth 23 to the first adjacent cutter tooth 24 or the second cutter tooth, the first cutter stop 41 is closest to the outer periphery 12. In one or more cutter teeth extending from the first cutter tooth 23 to the second adjacent cutter tooth 25 or the third cutter tooth, the first adjacent cutter tooth 24 or the second cutter tooth is closest to the outer periphery 12.

[0075] The first cutter 23 includes a cutter section 44 extending between the first baffle axis 410 and the second baffle axis 420. The cutter section 44 is the boundary section between the high pressure inside the mill and the low pressure outside the mill. The width of the cutter section 44 along a width direction 45 perpendicular to the first cutter axis 230 is greater than the width of the remaining portion 46 of the first cutter 23 outside the cutter section 44 along the width direction 45. Therefore, the first cutter 23 includes an additional first lateral portion 47 in the cutter section 44. The first lateral portion 47 in FIG3 is present at a first lateral side 28, which, in the example of FIG3, is located outside the first baffle 41, towards the outer perimeter 12. With respect to the flow of lignocellulosic material, the first lateral portion 47 is located downstream of the first cutter 23 in FIG2.

[0076] Alternatively, as shown in FIG4, the first lateral portion 47 may be located on the second lateral side 29 of the first cutter tooth 23. With respect to the flow of lignocellulosic material, the first lateral portion 47 is located upstream of the first cutter tooth 23 in FIG3.

[0077] It should be noted that although Figures 2, 3, and 14 show multiple blades 20 and multiple sprue blocks 30 drawn with outlines, while Figures 4 through 13 show blades and sprue blocks drawn with solid black blocks, this difference in drawing style is not of technical significance and is only used to facilitate understanding of the various embodiments described herein, unless otherwise stated.

[0078] Another alternative is that the first cutter tooth 23 includes a first lateral portion 47 located at a first lateral side 28 and a second lateral portion 48 located at a second lateral side 29. In other words, it is simultaneously located on both the downstream and upstream sides of the first cutter tooth 23. Examples of this configuration are shown in Figures 5 to 14. The embodiments in Figures 5 to 14 illustrate the first lateral portion 47 and the second lateral portion 48, but it is also possible to have only one of these lateral portions. These Figures 5 to 14 are used to illustrate other configurations, but are not limited to having two lateral portions.

[0079] The cutting tooth segment 44 may include a first lateral edge 61 and a second lateral edge 62 opposite to the first lateral edge 61. The first lateral edge 61 may be at least partially offset relative to the first cutting tooth axis 230 compared to a corresponding lateral edge of the remainder 46 of the first cutting tooth 23. Alternatively, the second lateral edge 62 may be at least partially offset relative to the first cutting tooth axis 230 compared to a corresponding second lateral edge of the remainder 46 of the first cutting tooth 23.

[0080] The first baffle 41 may extend from the first side toward the edge 61. The second baffle 42 may extend from the second side toward the edge 62.

[0081] When the additional first lateral portion 47 is downstream of the first cutter tooth and the first lateral edge 61 is offset, the second slurry stop 42 is closer to the outer periphery 12 than the first slurry stop 41.

[0082] When the additional first lateral portion 47 is upstream of the first cutter tooth and the second lateral edge 62 is offset, the second slurry stop 42 is closer to the outer periphery 12 than the first slurry stop 41. When the first lateral portion 47 is upstream of the first cutter tooth and the first lateral edge 61 is offset, the first slurry stop 41 is closer to the outer periphery 12 than the second slurry stop 42.

[0083] The plurality of cutting teeth 20 may include one or more groups of cutting teeth (Figure 5), each group of cutting teeth including a first cutting tooth 23, a first adjacent cutting tooth 24 or a second cutting tooth, a second adjacent cutting tooth 25 or a third cutting tooth.

[0084] Multiple blade teeth 20 and multiple blade baffles 30 can be arranged in multiple patterned regions (Figure 1). The first patterned region 8 and the second patterned region 9 are positioned side by side to cover at least a portion of the blade surface 13. Each of the first patterned region 8 and the second patterned region 9 includes one or more blade teeth from one or more sets of blade teeth.

[0085] The cutting teeth groups can overlap each other, such that the first adjacent cutting tooth 24 or the second cutting tooth of the first cutting tooth group 17 is also the first cutting tooth of the second cutting tooth group 18, as shown in FIG. 5. The first cutting tooth group 17 includes a cutting tooth as a first cutting tooth 23, a second cutting tooth (or a third cutting tooth 25) as a first adjacent cutting tooth 24, and a third cutting tooth (or a second cutting tooth 24) as a second adjacent cutting tooth 25. The second cutting tooth group 18 includes a third cutting tooth 25 as a first cutting tooth, a first cutting tooth 23 (or a cutting tooth 26) as a first adjacent cutting tooth, and a cutting tooth 26 (or a first cutting tooth 23) as a second adjacent cutting tooth. This configuration of these cutting tooth groups is a result of each outermost slurry stop being offset relative to the next outermost slurry stop. In these cases, the first cutting tooth includes a first lateral portion 47 or a second lateral portion 48 or both.

[0086] The cutter tooth 26 extends along the cutter tooth axis 260. The slurry stop 49 extends between the third cutter tooth 25 and the cutter tooth 26. The slurry stop 49 is another example of the slurry stop closest to the outer perimeter 12, and in this example, it is the slurry stop that extends from the third cutter tooth 25 to the cutter tooth 26, wherein the third cutter tooth 25 can be regarded as the first adjacent cutter tooth of the cutter tooth 26.

[0087] Instead of Figure 5, the second cutter group 18 may include a cutter 26 as its first cutter, and a third cutter 25 which is either the first or second adjacent cutter. Another adjacent cutter is not shown in Figure 5, but in this example, that adjacent cutter will face to the right of the cutter 26. This configuration results from the arrangement of two outermost baffles extending from opposite sides of the plurality of cutters 20 without offset. An example of this is shown in Figure 14, where the baffles marked 410 and 420 are not offset relative to each other in the direction along the third cutter 25. In other words, the first and second baffles are substantially aligned. Therefore, there is no widening of the third cutter 25 in this case.

[0088] Alternatively, the first set of cutting teeth 17 and the second set of cutting teeth 18 are adjacent to each other, that is, the cutting teeth are not part of more than one set of three cutting teeth. This configuration is the result of at least three adjacent outermost sprue stops being substantially aligned.

[0089] The number of first pattern regions 8 and second pattern regions 9 may include first pattern regions 8 with cutting teeth and slurry baffles, and second pattern regions 9 with cutting teeth and slurry baffles (FIG. 1). The orientation of the second pattern region 9 is different from that of the first pattern region 8. The first pattern regions 8 and the second pattern regions 9 are positioned side by side relative to each other to cover at least a portion of the finishing section 14. The respective angle (α) of the slurry baffles for each pattern is different. In the second pattern region 9 of FIG. 1, the angle of the plurality of cutting teeth 20 relative to the clockwise rotation direction D is smaller than the angle of the plurality of cutting teeth 20 in the first pattern region 8 relative to the clockwise rotation direction D.

[0090] One or more connecting cutter teeth 82 and / or connecting slurry blocks 84 can be provided between each pattern, connecting cutter teeth 82 and / or connecting slurry blocks 84 connecting the corresponding cutter teeth and / or slurry blocks of the first pattern area 8 and the second pattern area 9. The cutter teeth group of the first pattern area 8 may not overlap with the cutter teeth group of the second pattern area 9.

[0091] The first baffle 41 may be closer to the outer perimeter 12 than the second baffle 42. Alternatively, the second baffle 42 may be closer to the outer perimeter 12 than the first baffle 41. This configuration is mainly shown in Figures 3, 4 and 5.

[0092] The toothed section 44, the first lateral portion 47, and / or the second lateral portion 48 can have different shapes. As shown in Figures 1 to 5, when viewed from a direction perpendicular to the blade 10, the toothed section 44 can have a triangular shape. The toothed section 44 may include an inner end portion 54 closest to the inner periphery 11 and an outer end portion 55 closest to the outer periphery 12, wherein the width of the toothed section 44 at the inner end portion 54 is greater than the width of the toothed section 44 at the outer end portion 55. In this way, a triangle can be formed, especially when the first lateral edge 61 or the second lateral edge 62 (whichever is offset) is formed straight.

[0093] As shown in Figure 6, when viewed from a direction perpendicular to the blade 10, the toothed section 44, the first lateral portion 47, and / or the second lateral portion 48 may have a rectangular shape.

[0094] Alternatively, when viewed from a direction perpendicular to the blade 10, the toothed section 44, the first lateral portion 47 and / or the second lateral portion 48 may have a folded shape (Figs. 7, 8 and 9), a concave arc shape (Fig. 10), a convex arc shape (Fig. 11), a concave shape (Fig. 12) and a convex shape (Fig. 13).

[0095] The shapes of the first lateral portion 47 and the second lateral portion 48 may be the same or different.

[0096] Typically, each of the plurality of cutter tooth axes may not intersect with another of the plurality of cutter tooth axes within the finishing section 14. Additionally or alternatively, each of the plurality of slurry baffle axes may not intersect with another of the plurality of slurry baffle axes within the finishing section 14.

[0097] The arrangement of the plurality of cutter teeth 20 such that the plurality of cutter teeth 20 are inclined relative to the radial direction R to form a cutter tooth angle α of less than 90° in the clockwise direction (Figure 4). In some embodiments, the plurality of cutter teeth 20 are parallel to each other, but in other embodiments, at least one of them may not be parallel to the other cutter teeth. Furthermore, in some embodiments, the plurality of cutter teeth 20 form a straight line, but in some embodiments, the plurality of cutter teeth 20 may be curved. Furthermore, in some embodiments, the plurality of cutter teeth 20 may vary across the blade 10 such that some of them form a straight line while others are curved, and some of them are parallel while others are not. At the inner cutter tooth tip 22, the plurality of cutter teeth 20 preferably taper towards the blade surface 13. The cutter tooth angle α of each of the plurality of cutter teeth 20 may be different, but advantageously may be in the range of 5° to 60°.

[0098] At least one slurry stop is also provided on the finishing section 14, connecting at least two cutting teeth. Each of the plurality of slurry stops 30 extends from the outer slurry stop end 31 to the inner slurry stop end 32 (FIG. 3), wherein the outer slurry stop end 31 is closer to the outer periphery 12 than the inner slurry stop end 32. In the embodiment of FIG. 2, the plurality of slurry stops 30 are further arranged such that movement along the slurry stop dam extension, i.e., movement along each of the plurality of slurry stops 30 from the inner slurry stop end 32 to the outer slurry stop end 31, is also movement along a first circumferential direction D. This means that the plurality of slurry stops 30 are tilted relative to the radial direction R to form a slurry stop angle of less than 90° in the counterclockwise direction. The slurry stop angle β of the plurality of slurry stops 30 may be different, but advantageously can be in the range of 30° to 85°. In embodiments where the plurality of slurry stops 30 are bent, the slurry stop angle β can be appropriately reduced when moving from the outer slurry stop end 31 toward the inner slurry stop end 32.

[0099] With multiple blades 30 connected to multiple 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 can advantageously be in the range of 30° to 85°, which ensures efficient grinding of lignocellulosic materials and reduced energy consumption.

[0100] 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 from the inner periphery 11 to the outer periphery 12 across the blade 10, the cutter tooth angle α decreases, while the baffle angle β increases.

[0101] The plurality of baffles 30 shown in Figure 2 are arranged such that two cutter teeth are connected by more than one baffle. The plurality of baffles 30 are arranged along the same plurality of cutter teeth 20, but at different distances from the inner periphery 11. In other embodiments, the plurality of baffles 30 may alternatively be arranged such that only some of the plurality of cutter teeth 20 connected by one baffle are connected by another baffle closer to the inner periphery 11, or such that each cutter tooth is connected to only one baffle at each lateral side of the corresponding cutter tooth.

[0102] Multiple baffles 30 can each form a straight line or a curve, and they can be parallel or non-parallel to each other as needed.

[0103] The fact that the inner tooth ends 22 of the plurality of cutting teeth 20 are further arranged than the outer tooth ends 21 along the first axial direction D means that the plurality of cutting teeth 20 can lift the lignocellulose material from the cutting tooth grooves 40 into the finishing gap to improve finishing, while allowing the lignocellulose material to be effectively transported from the inner periphery 11 across the blade 10 to the outer periphery 12. Examples of grooves 40 are shown in FIG3, namely grooves 51 and 52. Groove 51 is arranged on its inner periphery side adjacent to the first baffle 41 and is arranged between the first cutting tooth 23 and the first adjacent cutting tooth 24 or the second cutting tooth. Groove 52 is arranged on its inner periphery side adjacent to the second baffle 42 and is arranged between the first cutting tooth 23 and the second adjacent cutting tooth 25 or the third cutting tooth. Groove 52 is further defined by a third baffle 43, which is the second outermost baffle relative to the second baffle 42.

[0104] In the embodiment of Figure 2, the height of the plurality of paddle stops 30 is preferably substantially equal to the tooth height of one or more corresponding blades at which the plurality of paddle stops 30 intersect. This means that the plurality of paddle stops 30 raise the cellulose material all the way to the finishing gap and prevent lignocellulosic material not finished by the plurality of blades 20 from crossing the plurality of paddle stops 30. The paddle stop height being substantially equal to the blade height should be understood to mean that they are equal within manufacturing tolerances, or at least that the difference between them does not exceed 10% of their height from the blade surface 13. In the first embodiment, all paddle stops have this paddle stop height, but in other embodiments, at least one of them may be lower. A paddle stop height substantially equal to the blade height is also advantageous in increasing the pressure between the blades during finishing.

[0105] The embodiment of the blade 10 shown in Figure 14 includes a mounting hole 150 for mounting the blade 10, and the blade 10 may be a blade segment.

[0106] 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.

[0107] The grinding 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 the outer portion 15 disclosed above and in Figure 5. Portions may also include grinding machine teeth arranged between the grinding portion 14 and the inner periphery 11. Furthermore, at least one portion of the blade surface 13 may be without grinding machine teeth, and such portions may be arranged near the inner periphery 11, near the outer periphery 12, or at any other location on the blade surface.

[0108] Furthermore, in some embodiments, there may be two or more finely ground portions 14 on the blade surface 13 according to the present patent, while another portion includes finely ground mill teeth or has no finely ground mill teeth between them.

[0109] This patent disclosure also relates to a fine grinding mill comprising at least one blade 10 according to any embodiment of the patent disclosure herein. In some embodiments, the fine grinding mill may include two blades 10 according to this patent disclosure, one blade being arranged as a rotor-side blade and the other as a stator-side blade. In other embodiments, one blade 10 according to this patent disclosure 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.

[0110] 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 (10) for a fine grinding mill (1) for fine grinding lignocellulosic materials, the blade (10) comprising a blade surface (13) configured to face another blade of the fine grinding mill (1) and defined by an inner periphery (11) and an outer periphery (12), wherein, The blade surface (13) has a finely ground portion (14), the finely ground portion comprising: a plurality of cutting teeth (20) protruding from the blade surface (13), wherein each of the plurality of cutting teeth extends at least partially along a corresponding cutting tooth axis of a plurality of cutting tooth axes, wherein each corresponding cutting tooth axis extends from the inner periphery (11) toward the outer periphery (12), wherein the plurality of cutting teeth (20) includes a first cutting tooth (23) extending along a first cutting tooth axis (230) of the plurality of cutting tooth axes; and a plurality of blade stops (30), each blade stop Extending along a corresponding axis of one of the plurality of baffle axes and between two adjacent cutter teeth (20), wherein the plurality of baffles (30) includes a first baffle (41) extending along a first baffle axis (410) and a second baffle (42) extending along a second baffle axis (420), wherein the first baffle axis (410) is offset from the second baffle axis (420) in a direction along the first cutter tooth axis (230), wherein the first baffle (41) extends from a first side of the first cutter tooth (23) towards The side (28) extends to the first adjacent cutter (24) of the plurality of cutter teeth (20), and the second baffle (42) extends from the second lateral side (29) of the first cutter tooth (23) opposite to the first lateral side (28) to the second adjacent cutter tooth (25) of the plurality of cutter teeth (20), wherein the first baffle (41) is closest to the outer periphery (12) among one or more baffles extending from the first cutter tooth (23) to the first adjacent cutter tooth (24), wherein the second baffle (42) extends from the first cutter tooth (23) to the second adjacent cutter tooth (25). The first cutter (23) extends to one or more paddle stops closest to the outer periphery (12), wherein the first cutter (23) includes a cutter section (44) extending between the axis of the first paddle stop (410) and the axis of the second paddle stop (420), characterized in that the width of the cutter section (44) in the width direction (45) perpendicular to the axis of the first cutter (230) is greater than the width of the remaining portion (46) of the first cutter (23) outside the cutter section (44) in the width direction (45).

2. The blade (10) according to claim 1, characterized in that, The plurality of cutting teeth (20) includes one or more groups of cutting teeth, each group of cutting teeth including the first cutting tooth (23), the first adjacent cutting tooth (24) and the second adjacent cutting tooth (25).

3. The blade (10) according to claim 2, characterized in that, The plurality of blades (20) and the plurality of blade baffles (30) are disposed in a plurality of patterned regions, wherein the patterned regions are positioned side by side to cover at least a portion of the blade surface (13), wherein each patterned region includes one or more blades from the one or more sets of blades.

4. The blade (10) according to claim 2 or 3, characterized in that, The tooth groups overlap each other such that: the first adjacent tooth (24) of the first tooth group (17) in the one or more tooth groups is also the first tooth of the second tooth group (18) in the one or more tooth groups; and / or the first adjacent tooth (24) of the first tooth group (17) in the one or more tooth groups is also the second adjacent tooth of the second tooth group (18) in the one or more tooth groups; and / or the second adjacent tooth (25) of the first tooth group (17) in the one or more tooth groups is also the first tooth of the second tooth group (18) in the one or more tooth groups. A cutting tooth; and / or the second adjacent cutting tooth (25) of the first cutting tooth group (17) in the one or more cutting tooth groups is also the first adjacent cutting tooth of the second cutting tooth group (18) in the one or more cutting tooth groups; and / or the first cutting tooth (23) of the first cutting tooth group (17) in the one or more cutting tooth groups is also the first adjacent cutting tooth of the second cutting tooth group (18) in the one or more cutting tooth groups; and / or the first cutting tooth (23) of the first cutting tooth group (17) in the one or more cutting tooth groups is also the second adjacent cutting tooth of the second cutting tooth group (18) in the one or more cutting tooth groups.

5. The blade (10) according to claim 2 or 3, characterized in that, The plurality of cutting teeth includes a plurality of cutting tooth groups, which are adjacent to each other.

6. The blade (10) according to claim 3, characterized in that, The plurality of patterned regions include: a first patterned region (8) of blades and a slurry baffle; a second patterned region (9) of blades and a slurry baffle, wherein the orientation of the second patterned region (9) is different from that of the first patterned region (8), wherein the first patterned region (8) and the second patterned region (9) are positioned side by side relative to each other to cover at least a portion of the polishing portion (14); and one or more connecting blades (82) and / or connecting slurry baffles (84), the one or more connecting blades (82) and / or connecting slurry baffles (84) connecting the corresponding blades and / or slurry baffles of the first patterned region (8) and the second patterned region (9), wherein the set of blades of the first patterned region (8) does not overlap with the set of blades of the second patterned region (9).

7. The blade (10) according to any one of claims 1 to 3, characterized in that: The plurality of cutter teeth (20) are arranged such that movement along the axes of the plurality of cutter teeth from the outer periphery (12) to the inner periphery (11) is also movement along the first circumferential direction (D); and / or the plurality of baffles (30) are arranged such that movement along the respective baffle axes of the plurality of baffles (30) from the inner periphery (11) to the outer periphery (12) is also movement along the first circumferential direction (D), the plurality of baffle axes including the first baffle axis (410) and the second baffle axis (420).

8. The blade (10) according to any one of claims 1 to 3, characterized in that, The first baffle (41) is closer to the outer periphery (12) than the second baffle (42).

9. The blade (10) according to any one of claims 1 to 3, characterized in that, The second baffle (42) is closer to the outer periphery (12) than the first baffle (41).

10. The blade (10) according to any one of claims 1 to 3, characterized in that, The cutting tooth segment (44) includes a first lateral edge (61) and a second lateral edge (62) opposite to the first lateral edge (61), wherein: the first lateral edge (61) is at least partially offset relative to the first cutting tooth axis (230) compared to the corresponding lateral edge of the remaining portion (46) of the first cutting tooth (23); or the second lateral edge (62) is at least partially offset relative to the first cutting tooth axis (230) compared to the corresponding second lateral edge of the remaining portion (46) of the first cutting tooth (23).

11. The blade (10) according to claim 10, characterized in that, The first slurry block (41) extends from the first lateral edge (61); the second slurry block (42) extends from the second lateral edge (62); when the first lateral edge (61) is offset, the second slurry block (42) is closer to the outer periphery (12) than the first slurry block (41); and when the second lateral edge (62) is offset, the first slurry block (41) is closer to the outer periphery (12) than the second slurry block (42).

12. The blade (10) according to any one of claims 1 to 3, characterized in that, When viewed from a direction perpendicular to the blade (10), the toothed section (44) has a triangular shape.

13. The blade (10) according to any one of claims 1 to 3, characterized in that, The toothed section (44) includes an inner end (54) closest to the inner periphery (11) and an outer end (55) closest to the outer periphery (12), wherein the width of the toothed section (44) at the inner end (54) is greater than the width of the toothed section (44) at the outer end (55).

14. The blade (10) according to any one of claims 1 to 3, characterized in that, When viewed from a direction perpendicular to the blade (10), the toothed section (44) has a rectangular shape.

15. The blade (10) according to any one of claims 1 to 3, characterized in that, When viewed from a direction perpendicular to the blade (10), the toothed section (44) has one of the following shapes: angled shape, concave arc shape, convex arc shape, concave shape, and convex shape.

16. The blade (10) according to any one of claims 1 to 3, characterized in that: Each of the plurality of cutting tooth axes does not intersect with another cutting tooth axis in the fine grinding section (14); and / or each of the plurality of cutting tooth axes does not intersect with another cutting tooth axis in the fine grinding section (14).

17. A grinding mill (1) for fine grinding of lignocellulosic materials, comprising at least one blade (10) according to any one of claims 1 to 16.

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