Blade element for a refiner
By introducing a uniform zone into the blade element of the fine grinding mill, the problem of debris clogging in low-concentration fine grinding is solved, achieving efficient and uniform flow of fiber materials and high-quality fine grinding, thus improving production efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- VALMET TECH OY
- Filing Date
- 2021-05-12
- Publication Date
- 2026-06-26
Smart Images
Figure CN115516166B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a fine grinding mill for fine grinding of fibrous materials, and more particularly to a blade element for a fine grinding mill for fine grinding of fibrous materials. Background Technology
[0002] A fine grinding mill for refining fibrous materials (such as a fine grinding mill for manufacturing mechanical pulp or a fine grinding mill used in any low-concentration fine grinding) typically comprises two fine grinding elements that are positioned opposite each other and rotate relative to each other (i.e., one or both rotate). Each fine grinding element includes a fine grinding surface with teeth and grooves between them. The teeth are used for fiber separation and fine grinding of the material to be fined, and the grooves are used for conveying the material to be fined forward along the fine grinding surface. The fine grinding surface of the fine grinding element is typically formed by a number of blade segments (grinding discs) fixed to the body of the respective fine grinding element. Therefore, the complete fine grinding surface of the fine grinding element is formed by the fine grinding surfaces of a number of blade segments that are fixed close together within the fine grinding element.
[0003] All operations involved in pulp production from lignocellulosic materials generate wood chips, an undesirable quality problem. Wood chips are particles, fiber bundles, or sawdust produced during cooking or mechanical processing when the lignocellulosic material is not completely broken down into fibers. Wood chips not only contaminate the quality of the produced pulp but also degrade the operation of some processing equipment, such as grinding mills.
[0004] In the manufacture of chemithermomechanical pulps (CTMPs), the application of low-concentration polishing (i.e., LC polishing) is gradually increasing. In low-concentration polishing, the concentration of the material to be polished is less than 6%, typically between 1% and 4%. In low-concentration polishing, when the particle size distribution of the pulp is very wide, the problem of producing high-quality pulp becomes apparent, especially in terms of debris control. Debris tends to clog the polishing surface, thereby reducing the quality of the polished material and the production capacity of the polishing mill. Summary of the Invention
[0005] The purpose of this invention is to provide a novel blade element for a fine grinding mill for fine grinding fiber materials, and a novel fine grinding mill for fine grinding fiber materials.
[0006] The present invention is based on the concept of at least one equalizing pocket, which extends along the finely ground surface of the blade element and spans multiple cutting teeth and multiple cutting grooves, for equalizing the flow of fibrous material along the finely ground surface.
[0007] In the equilibrium zone, at least a portion of the flow of the fiber material to be finely ground on the fine-grinding surface is interrupted and allowed to be balanced or equilibriumd before it can travel further on the fine-grinding surface. Attached Figure Description
[0008] The present invention will now be described in more detail with reference to the accompanying drawings and preferred embodiments, in which:
[0009] Figure 1 This is a schematic side view of a conical grinding mill shown in cross-section;
[0010] Figure 2 It is applicable Figure 1 A schematic plan view of the blade element in a fine grinding mill; and
[0011] Figure 3 yes Figure 2 A schematic plan view showing the details of the blade element.
[0012] For clarity, the accompanying drawings illustrate some embodiments of the invention in a simplified manner. In the drawings, similar reference numerals denote similar elements. Detailed Implementation
[0013] Figure 1 A side view of a conical grinding mill 1 is shown schematically in cross-section. This grinding mill can be used to grind fibrous materials such as wood containing lignocellulose or other fibrous materials suitable for making paper or paperboard. Figure 1 The grinding mill 1 shown is conical, but disc grinding mills, conical-disc grinding mills, and cylindrical grinding mills can also be used as examples. Typically, a grinding mill includes: at least two substantially opposed grinding elements, at least one of which is rotating; and a grinding chamber formed between each pair of substantially opposed grinding elements. Below, a grinding mill having only one rotatable grinding element is described.
[0014] Figure 1 The grinding mill 1 includes a frame 2 and a stationary grinding element 3, namely a stator 3, supported on the frame 2. The frame 2 provides the body for the stator 3, unless the stator 3 has a separate body to be fixed to the frame 2 of the grinding mill 1.
[0015] The stator 3 includes one or more stator blade elements 4, each including teeth and grooves between them. The teeth and grooves of each of the one or more stator blade elements 4 form a polished surface 5 of the respective blade element 4. The complete polished surface of the stator 3 is formed either by the polished surface 5 of a single stator blade element 4 extending over the entire circumference of the stator 3, or by the polished surfaces 5 of two or more blade elements 4 having the form of blade segments and being fixed abutting each other within the stator 3, thereby providing a complete polished surface 5 extending over the entire circumference of the stator 3. In the latter case, the polished surface 5 of each stator blade segment 4 only provides a portion of the polished surface of the stator 3. For clarity, the polished surface of each of the one or more stator blade elements 4 and the entire polished surface of the stator 3 are indicated herein by the same reference numeral 5. Furthermore, the same reference numeral 4 can be used to indicate segmental blade elements of the stator 3 and single blade elements extending over the entire circumference of the stator 3.
[0016] The grinding mill 1 also includes a rotatable grinding element 6, namely, a rotor 6. The rotor 6 includes a hub 7. The rotor 6 also includes one or more rotor blade elements 8 supported to the hub 7, each of the one or more rotor blade elements 8 including cutting teeth and cutting grooves located between the cutting teeth. The cutting teeth and cutting grooves of each of the one or more rotor blade elements 8 form the grinding surface 9 of the respective blade element 8. The complete grinding surface of the rotor 6 is formed either by the grinding surface 9 of a single rotor blade element 8 extending over the entire circumference of the rotor 6, or by the grinding surfaces 9 of two or more blade elements 8 having the form of blade segments and being fixed abutting each other within the rotor 6, thereby providing a complete grinding surface 9 extending over the entire circumference of the rotor 6. In the latter case, the grinding surface 9 of each rotor blade segment 8 only provides a portion of the grinding surface of the rotor 6. For clarity, the grinding surface of each of the one or more rotor blade elements 8 and the entire grinding surface of the rotor 6 are indicated herein by the same reference numeral 9. Furthermore, the same reference numeral 8 in the following figures can be used to denote segmental blade elements of rotor 6 as well as single blade elements extending over the entire circumference of rotor 6.
[0017] The hub 7 of rotor 6 is connected to drive motor 10 via shaft 11, so that rotor 6 can rotate relative to stator 3 in the direction of arrow RD, for example, arrow RD thus indicates the expected rotation direction RD of rotor 6.
[0018] The fine grinding mill 1 may also include a loading device, for clarity, Figure 1The loading device is not shown in the diagram. The loading device can be used to move the rotor 6 attached to the shaft 11 back and forth (as schematically shown by arrow A) to adjust the size of the fine grinding gap 12 (i.e., the fine grinding chamber 12) between the stator 3 and the rotor 6, in which the fibrous material is actually finely ground. The structure and operation of various suitable loading devices are generally known to those skilled in the art of fine grinding, and therefore will not be disclosed in further detail here.
[0019] The fiber material to be finely ground is fed into the fine grinding mill 1 via the feed channel 13 in the manner indicated by arrow F. The fiber material fed into the fine grinding mill 1 enters the fine grinding chamber 12 through the first end 12' with a smaller diameter or the feed end 12'. In the fine grinding chamber 12, the fiber material is separated and finely ground, while the water contained in the material is evaporated. The finely ground fiber material flows out of the fine grinding chamber 12 through the second end 12'' with a larger diameter or the discharge end 12'' and enters the discharge chamber 14. The finely ground material is discharged from the fine grinding mill 1 from the discharge chamber via the discharge channel 15, as schematically shown by arrow D.
[0020] It should be emphasized that, in addition to being applicable to conical grinding mills, the blade elements of the solutions described herein are also applicable to disc grinding mills and cylindrical grinding mills, as well as grinding mills that include both conical and disc-shaped sections.
[0021] Figure 2 This is a schematic top plan view of blade elements 4 and 8, which have the form of blade segments 4 and 8. These blade segments 4 and 8 are adapted to form part of the fine-ground surfaces 5 and 9 of the stator 3 or rotor 6, thereby... Figure 2 The necessary number of blade segments 4, 8 are arranged close together around the circumference of the stator 3 or rotor 6 to provide fully ground surfaces 5, 9. The embodiments of the blade elements disclosed below are also applicable to a certain extent to single blade elements extending over the entire circumference of the stator 3 or rotor 6. Figure 3 yes Figure 2 A schematic top-down view showing the details of the blade element.
[0022] The blade segment 8 includes finely ground surfaces 5 and 9 on its front surface 22. These surfaces are provided with cutting teeth 16 and grooves 17 between the cutting teeth, extending along the front surface 22 of the blade segments 4 and 8. The cutting teeth 16 and grooves 17 have a longitudinal direction and a width direction (or a transverse direction substantially intersecting their longitudinal direction). The cutting teeth 16 are used for fiber separation and fine grinding of the material to be finely ground, and the grooves 17 are used for forward conveying of the material along the finely ground surfaces 5 and 9.
[0023] Blade segments 4 and 8 include an inner end edge 18, a first end edge 18, or a feed end edge 18, which points towards the first end 12' of the fine grinding chamber 12, that is, towards the end with the smaller diameter of the fine grinding elements 3 and 6. The fibrous material to be finely ground is fed or supplied to the fine grinding surfaces 5 and 9 over the first end edge 18.
[0024] Blade segments 4 and 8 also include an outer end edge 19, a second end edge 19, or a discharge end edge 19, which points towards the second end 12'' of the fine grinding chamber 12, that is, towards the end with the larger diameter of the fine grinding elements 3 and 6. The finely ground fiber material exits from the fine grinding surfaces 5 and 9 across the second end edge 19.
[0025] In conical and cylindrical grinding mills, the inner end edge 18 of blade segments 4 and 8 serves as the axial inner end 18 of blade segments 4 and 8, and the outer end edge 19 of blade segments 4 and 8 serves as the axial outer end 19 of blade segments 4 and 8. The direction from the axial inner end 18 to the axial outer end 19 is the axial direction of blade segments 4 and 8. In disc grinding mills, the inner end edge of a blade segment is the radial inner end of the blade segment, and the outer end edge of a blade segment is the radial outer end of the blade segment. Therefore, the direction from the radial inner end to the radial outer end provides the radial direction of the blade segment. In other words, blade segments 4 and 8 have a longitudinal direction extending between the inner end edge 18 and the outer end edge 19, as shown in... Figure 2 The direction is indicated by the arrow LD extending from the inner end edge 18 of the blade segments 4 and 8 to the outer end edge 19. When the blade segments 4 and 8 are installed in the grinding mill, the longitudinal direction LD of the blade segments 4 and 8, or its projection, is substantially parallel to the axial direction of the grinding mill in the case of cylindrical and conical grinding mills, and substantially parallel to the radial direction of the grinding mill in the case of disc grinding mills. For blade segments 4 and 8 used in conical and cylindrical grinding mills, the longitudinal direction LD of the blade segments 4 and 8 therefore corresponds to the aforementioned axial direction of the blade segments 4 and 8, while for blade segments 4 and 8 used in disc grinding mills, the longitudinal direction LD of the blade segments 4 and 8 therefore corresponds to the aforementioned radial direction of the blade segments 4 and 8.
[0026] Blade segments 4 and 8 also include a first side edge 20 or front side edge 20 extending from the inner end edge 18 of blade segments 4 and 8 to the outer end edge 19 of blade segments 4 and 8. The first side edge 20 is the edge where blade segments 4 and 8 first meet the edge of the opposing blade segment during rotation of the rotor 6. Thus, in the rotor 6, the side edge of blade segment 8 is positioned in the intended rotation direction RD of the rotor 6, and in the stator 3, the side edge of blade segment 4 is positioned in the opposite direction to the intended rotation direction RD of the rotor 6.
[0027] Blade segments 4 and 8 also include a second side edge 21 or a rear side edge 21, which is opposite to the first side edge 20 and extends from the inner end edge 18 of blade segments 4 and 8 to the outer end edge 19 of blade segments 4 and 8. Therefore, the second side edge 21 is also the edge where the blade segments 4 and 8 finally meet the edge of the opposite blade segment during the rotation of the rotor 6. Thus, in the rotor 6, the side edges of blade segment 8 point in the opposite direction to the intended rotation direction RD of the rotor 6, and in the stator 3, the side edges of the blade segments point in the intended rotation direction RD of the rotor 6. Figure 2 In this embodiment, the first side edge 20 and the second side edge 21 are straight, but they can also be curved. The direction of the blade segments 4 and 8 extending between the first side edge 20 and the second side edge 21, perpendicular to the longitudinal direction LD of the blade segments 4 and 8, is the circumferential direction CD of the blade segments 4 and 8. Therefore, the circumferential direction CD of the blade segments 4 and 8 forms the normal N of the longitudinal direction LD of the blade segments 4 and 8.
[0028] The inner end edge 18 and the outer end edge 19, together with the first side edge 20 and the second side edge 21, define the outer periphery of the blade segments 4 and 8.
[0029] The polished surfaces 5 and 9 of the blade segments 4 and 8 also include multiple equalization zones 23, that is, at least one or more equalization zones 23 extending along the polished surfaces 5 and 9 of the blade segments 4 and 8. The equalization zone 23 is a portion of the polished surface 5 and 9 where the flow of fibrous material along the polished surface 5 and 9 is allowed to be balanced or equilibriumed before proceeding forward along the polished surface 5 and 9 again. The equalization zone 23 has a first end 23' and a second end 23'', thus the equalization zone 23 has a longitudinal direction or a direction extending between the first end 23' and the second end 23'', the longitudinal direction of the equalization zone 23 being... Figure 2 The line indicated by reference numeral 23l is schematically shown in the figure. The equalization zone 23 begins at a first end 23' from a tooth 16, extends across one or more teeth 16 and their adjacent cutting grooves 17, and terminates at a second end 23'' at another tooth 16. The start or end point of the equalization zone 23 may be located on adjacent blade segments 4, 8.
[0030] The balancing zone 23 is arranged to span a plurality of cutting teeth 16 and a plurality of cutting grooves 17 along its longitudinal direction 23l, i.e., at least one cutting tooth 16 or one or more cutting teeth 16 and corresponding cutting grooves 17 surrounding and / or remaining between the plurality of cutting teeth 16. Therefore, at a minimum, the balancing zone 23 may be arranged to span one cutting tooth 16, thereby extending over the single cutting tooth 16 and the cutting grooves 17 on both sides of that cutting tooth 16. However, typically, the balancing zone 23 is arranged to span at least two cutting teeth 16, thereby extending over the at least two cutting teeth 16 and the cutting grooves 17 between the at least two cutting teeth 16, and around the cutting groove 17 of the outermost cutting tooth 16 in the extending direction 23l of the balancing zone 23. Figure 2 In one embodiment, depending on the position of each equalization zone 23 in the polished surfaces 5, 9 of the blade segments 4, 8, the equalization zone 23 is arranged to extend over four to seven teeth 16. The number of teeth 16 spanned by the pocket 23 can range from one tooth 16 to any number of teeth; however, at least one pocket 23 must be formed between the side edges 20, 21 of the blade segments 4, 8.
[0031] The function of at least one equalization zone 23 is to provide an intentional or purposeful interruption in the otherwise substantially continuous advance or run of at least one cutter tooth 16 and corresponding cutter groove 17, thereby interrupting at least a portion of the flow of the fibrous material to be ground on the grinding surfaces 5, 9 from the first end edge 18 of the blade segments 4, 8 toward the second end edge 19 of the blade segments 4, 8, and allowing equalization or remixing at the equalization zone 23 before further travel toward the second end edge 19 of the blade segments 4, 8. The angle α between the longitudinal direction 23l of the equalization zone 23 and the axial direction A or radial direction of the blade segments 4, 8 is... 23l The angle is greater than 0 degrees but less than 90 degrees, preferably 10 degrees to 80 degrees, and more preferably 30 degrees to 80 degrees. Therefore, the longitudinal direction 23l of the equalization zone 23 is arranged to deviate from the axial / radial direction A of the blade segments 4 and 8 and from the direction of the normal N to the axial / radial direction A of the blade segments 4 and 8. The directions of the axial / radial direction A of the blade segments 4 and 8 and the direction of the normal N to the axial / radial direction A of the blade segments 4 and 8 are schematically shown in... Figure 2 As shown in the image.
[0032] exist Figure 2 In this embodiment, each equalization zone 23 is arranged to span the corresponding cutter tooth 16 and cutter groove 17 at an angle of approximately 90 degrees. Therefore, in Figure 2In this embodiment, the intersection angle between the longitudinal direction 23l of the equalization zone 23 and the blade teeth 16 is approximately 90 degrees. Typically, the intersection angle between the longitudinal direction of the equalization zone 23 and the blade teeth 16 can be 90 degrees ± 50 degrees. The effect of this angle range is that the extension direction of the equalization zone 23 deviates from the direction of the blade teeth 16 and the groove 17 to such an extent that at least a portion of the flow of the fibrous material is interrupted and allowed to be stabilized and then remixed at the equalization zone 23 before traveling further toward the second end edge 19 of the blade segments 4, 8, thus enabling better handling of debris.
[0033] Therefore, the longitudinal direction 23l of the equalization zone 23 is arranged to deviate from the direction of the cutter tooth 16 and from the axial / radial direction A and normal N of the blade segments 4 and 8.
[0034] Figure 2 The finishing surfaces 5 and 9 of the blade segments 4 and 8 collectively comprise three series 24 of equilibration zones 23 that are continuously and substantially correspondingly oriented, wherein the ends 23', 23'' of the equilibration zones 23 arranged continuously in series 24 of equilibration zones 23 are separated from each other by a single cutting tooth 16. Each series 24 of the continuously and substantially correspondingly oriented equilibration zones 23 is arranged to extend on at least a portion of the finishing surfaces 5 and 9 in a direction from the second side edge 21 of the blade segments 4 and 8 toward the first side edge 20 of the blade segments 4 and 8.
[0035] Typically, the polished surfaces 5 and 9 of the blade segments 4 and 8 may include at least one series 24 of at least two consecutive and substantially correspondingly oriented equalization zones 23, wherein each series 24 of equalization zones 32 is arranged to extend over at least a portion of the polished surfaces 5 and 9, and wherein the ends 23', 23'' of at least two consecutively arranged equalization zones 23 are spaced apart from each other by at least one cutting tooth 16. For the bag 23 closest to the side edges 20 and 21, i.e., the first or last bag 23 in the bag series 24, the separating cutting tooth 16 may and typically be located on the adjacent blade segments 4 and 8.
[0036] Compared to the potentially completely separate equilibrium zones 23 dispersed at random locations in the polished surfaces 5, 9, at least one series 24 of the equilibrium zones 23 are arranged to extend over at least a portion of the polished surfaces 5, 9 of the blade segments 4, 8. This provides an equilibration or balance effect that effectively allows the flow of fibrous material to occur along its circumference over a larger portion of the polished surfaces 5, 9 of the blade segments 4, 8.
[0037] The series of bags 23 can have several items. Figure 2In the middle, there are three series 24 with parallel orientation, but the mutual orientation of these three series can also be non-parallel, for example, such that the series 24 closer to the outer end edge 19 can be oriented at a steeper cross angle relative to the series 24 located on the inner side.
[0038] In the series 24 of equalization zones 23, the ends 23', 23'' of the continuously arranged equalization zones 23 are separated from each other by at least one cutter tooth 16. The effect of this feature is that the flow of fibrous material along the equalization zone 23 in at least a partial circumferential direction of the blade segments 4, 8 is interrupted at a certain point, that is, excessive flow of fibrous material in at least a partial circumferential direction of the blade segments 4, 8 is not allowed, and the fibrous material is forced to flow again mainly towards the discharge end edge 19 of the blade segments 4, 8, thus also preventing clogging of the finishing surfaces 5, 9 of the blade segments 4, 8. Therefore, at least one cutter tooth 16 located between two consecutive equalization zones 23 provides an element that separates the two consecutive equalization zones 23 from each other in the longitudinal direction of the series 24 of equalization zones 23 or terminates the equalization zones 23 at their respective ends 23', 23''.
[0039] In addition, refer to Figure 2 In one embodiment, the series 24 of the equalization zones 23 are arranged at an angle offset from the normal N of the axial / radial direction A of the blade segments 4, 8 at the grinding surfaces 5, 9. Therefore, the bags 23 are more evenly distributed along the axial / radial length of the grinding surface, rather than being located at the same axial / radial position. Typically, according to one embodiment, at least one series of at least two equalization zones are arranged at the grinding surface at an angle offset from the normal N of the axial / radial direction A of the blade elements. This has several advantages. Material flow toward the discharge end edge 19 is not obstructed and is maintained or improved; additionally, the wear of the blade elements is more uniform. Furthermore, pressure variations that may occur during the operation of the grinding mill can be avoided.
[0040] The disclosed blade segments 4, 8 have a specific intended orientation for mounting them in the grinding mill 1, in which the teeth 16 and the grooves 17 are angularly arranged relative to the intended rotational direction RD of the rotor 6 of the grinding mill 1 to promote the flow of fibrous material toward the second end edge 19 of the blade segments 4, 8. Simultaneously, at least one equalization zone 23 is angularly arranged relative to the intended rotational direction RD of the rotor 6 of the grinding mill 1 to prevent the flow of fibrous material toward the second end edge 19 of the blade segments 4, 8. Figure 2 In the implementation of the embodiment, this is achieved by arranging the cutting teeth 16 (and the corresponding cutting grooves 17) such that the angle α between the normal N of the blade segments 4, 8 on the leading edge 20 side relative to the axial direction A or the radial direction and the cutting teeth 16 (or the tangent of the cutting teeth 16) is... 16This is achieved at an angle greater than 90 degrees. In other words, the cutting teeth / grooves 16, 17 and the bag 23 or the series 24 of the bag 23 are inclined in opposite directions relative to each other with respect to direction A, which is the axial direction in the case of a conical / cylindrical grinding mill, or the radial direction in the case of a disc grinding mill.
[0041] By arranging the cutting teeth and corresponding grooves at an angle relative to the expected rotation direction RD of the rotor of the grinding mill, the flow of fibrous material toward the second end edge of the blade element is promoted, ensuring that the fibrous material to be ground has an overall flow direction toward the discharge end edge of the blade element, thereby preventing the grinding surface from being blocked by the fibrous material to be ground. However, by arranging at least one equalization zone at an angle relative to the expected rotation direction RD of the rotor of the grinding mill to prevent the flow of fibrous material toward the discharge end edge of the blade element, this effect is affected by at least a portion of the flow of fibrous material, which briefly interrupts the flow of material toward the discharge end edge of the blade element and allows it to equalize or balance before traveling further toward the discharge end edge of the blade element.
[0042] According to the embodiment of the equalization zone 23, the volume of the equalization zone 23 is arranged to decrease from the first end 23' toward the second end 23'' of the equalization zone 23. The decreasing volume of the equalization zone 23 from the first end 23' toward the second end 23'' forces the fiber material entering the equalization zone 23 to be equalized or balanced in the equalization zone 23, and then leaves the equalization zone 23 toward the discharge end edge 19 of the blade segments 4, 8.
[0043] The volume of the equalization zone 23 decreasing from the first end 23' toward the second end 23'' can be achieved by arranging at least one of the width and depth of the equalization zone 23 to decrease from the first end 23' toward the second end 23''. In other words, the width and / or depth of the equalization zone 23 can be arranged to decrease from the first end 23' toward its second end 23''.
[0044] The width of the equalization zone 23 refers to the measured dimension of the equalization zone 23 that substantially intersects the direction between the first end 23' and the second end 23'' of the equalization zone 23, and can be determined as the distance between the end 16a' of the cutting tooth 16a extending toward the equalization zone 23 from the first end edge 18 of the blade segments 4, 8 and the end 16b' of another cutting tooth 16b extending at least partially toward the second end edge 19 of the equalization zone 23 and substantially opposite the cutting tooth 16a mentioned herein. Figure 3 ).
[0045] The depth of the equalization zone 23 can be defined as the vertical distance between the bottom of the equalization zone 23 and the height (level) of the top surface of the blade tooth 16.
[0046] According to one embodiment of the equalization zone 23, at least one of the width and depth of the equalization zone 23 is arranged to dynamically decrease from a first end 23' toward a second end 23'' of the equalization zone 23. In other words, the width and / or depth of the equalization zone 23 is arranged to decrease dynamically (i.e., in a substantially continuous manner) from the first end 23' toward the second end 23'' of the equalization zone 23, thereby forcing the fiber material entering the equalization zone 23 to flow further toward the discharge end edge 19 of the blade segments 4, 8 in a substantially uniform manner away from the equalization zone 23, without causing undesirable turbulence in the flow of the fiber material. A stepped decrease in the width and / or depth of the equalization zone 23 is of course possible, but not preferred.
[0047] Refer again Figure 2 In one embodiment, the balancing zone 23 is arranged at an angle relative to the first end edge 18 and the second end edge 19 of the blade segments 4 and 8 at the polished surfaces 5 and 9 of the blade segments 4 and 8, such that the first end 23' of the balancing zone 23 is closer to the first end edge 18 of the blade segments 4 and 8 than the second end 23'' of the balancing zone 23. This embodiment (particularly in conjunction with the reduced volume of the balancing zone 23 toward its second end 23'') has the effect that the fibrous material entering the balancing zone 23 is forced to continue flowing toward the outer end edge 19 of the blade segments 4 and 8. This alignment of the balancing zone 23 also causes the series 24 of the balancing zone 23 to be aligned, wherein one end of the series 24 of the balancing zone 23 is closer to the first end edge 18 of the blade segments 4 and 8, and the other end of the series 24 of the balancing zone 23 is closer to the second end edge 19 of the blade segments 4 and 8. Thus, the series 24 of the balancing zone 23 is at least partially aligned or oriented toward the second end edge 19 of the blade segments 4 and 8.
[0048] In addition, Figure 2 In one embodiment, the volume of the equalization zone 23 that holds closer to the second end edge 19 of the blade segments 4, 8 is arranged to be smaller than the volume of the equalization zone 23 that holds closer to the first end edge 18 of the blade segments 4, 8. Typically, according to one embodiment of the blade element, the volume of at least one equalization zone that holds closer to the second end edge of the blade element is arranged to be smaller than the volume of at least one other equalization zone that holds closer to the first end edge of the blade element. This has the effect that the residence time of the fibrous material entering the equalization zone 23 is reduced toward the discharge end 12'' of the grinding chamber 12, thus the flow of the fibrous material toward the discharge end 12'' of the grinding chamber 12 is more efficient near the discharge end 12'' of the grinding chamber 12.
[0049] According to one embodiment of blade segments 4 and 8, particularly referring to Figure 3 The width W of the groove 17 extending at least partially from the equalization zone 23 toward the second end edge 19 of the blade segments 4 and 8 17 It is arranged to increase in the direction from the first end 23' of the equalization zone 23 toward the second end 23'' of the equalization zone 23. In general, it can therefore be determined that the equalization zone 23 has a first end 23' and a second end 23'', and the width W of the cutting groove 17 (i.e., those cutting grooves 17 spanned by the bag 23) extending at least partially from at least one equalization zone 23 toward the second end edge 19 of the blade element 4, 8 17 It is arranged to increase in the direction from the first end 23' of the equalization zone 23 toward the second end 23'' of the equalization zone 23. The width W of the tool groove 17 17 The arrangement is such that the kerf 17 increases substantially continuously at the equilibrium zone 23, such that the kerf 17 at the first end 23' of the equilibrium zone 23 is the narrowest, while the kerf 17 at the second end 23'' of the equilibrium zone 23 is the widest, and each kerf 17 closer to the second end 23'' of the equilibrium zone 23 is at least slightly wider than the kerf 17 closer to the first end 23''. When the material flow stabilizes at the equilibrium zone 23, the varying width of the kerf 17 allows fibers / debris / particles of different sizes to redistribute into the kerf 17 corresponding to their sizes. The kerf 17 widening in this order (i.e., from the first end 23' towards the second end 23'') helps ensure smooth particle flow. If the order were reversed, the widest kerf 17 might be filled with smaller particles, while larger debris would not find a suitable outlet. The width W of the kerf 17 at the first end 23' of the equilibrium zone 23 is... 17 For example, it can be 1mm-5mm, and the width W of the tool groove 17 at the second end 23'' of the equalization zone 23 is... 17 For example, it can be 5mm-10mm.
[0050] The increased width of the cutter groove 17 toward the second end 23'' of the equalization zone 23 ensures that larger debris entering the equalization zone 23 can also leave the equalization zone 23, thereby enabling fiber separation and fine grinding without clogging the fine grinding surfaces 5, 9. This embodiment (especially in conjunction with the reduced volume of the equalization zone 23 toward its second end 23'') effectively ensures that the slurry flow is forced to remix, thereby forcing the material, including debris, to leave the equalization zone 23 and flow toward the outer end edge 19 of the blade elements 4, 8.
[0051] It will be apparent to those skilled in the art that the concept of this invention can be implemented in various ways as technology advances. The invention and its embodiments are not limited to the examples described above, but can be varied within the scope of the claims.
Claims
1. A blade element (4, 8) for a fine grinding mill (1) for fine grinding fibrous materials, said blade element (4, 8) comprising: A first end edge (18) and a second end edge (19), the first end edge pointing towards the feed of the fiber material to be finely ground, and the second end edge pointing towards the discharge of the finely ground fiber material; and The finely ground surfaces (5, 9) include cutting teeth (16) and cutting grooves (17) located between the cutting teeth. The feature is that the polished surfaces (5, 9) include at least one equalization zone (23) extending along the polished surfaces (5, 9) of the blade elements (4, 8) and spanning multiple teeth (16) and multiple grooves (17) for equalizing the flow of the fibrous material along the polished surfaces (5, 9). The equalization zone (23) begins at a first end (23') from one tooth (16), extends across one or more teeth (16) and their adjacent grooves (17), and terminates at a second end (23'') at another tooth (16). The longitudinal direction (23l) of the equalization zone (23) is arranged to deviate from the direction of the cutting teeth (16), from the longitudinal direction (LD) of the blade elements (4, 8), and from the direction of the normal (N) of the longitudinal direction (LD) of the blade elements (4, 8). The equalization region (23) has a first end (23') and a second end (23''), and The volume of the equalization zone (23) is arranged to decrease from the first end (23') of the equalization zone (23) toward the second end (23'') of the equalization zone (23), wherein the first end (23') of the equalization zone (23) is closer to the edge (18) of the first end than the second end (23'') of the equalization zone (23).
2. The blade element according to claim 1, characterized in that, The polished surfaces (5, 9) include at least one series (24) having at least two consecutive and correspondingly oriented equalization zones (23), wherein each series (24) of the equalization zones (23) is arranged to extend over at least a portion of the polished surfaces (5, 9), and wherein the ends (23', 23'') of at least two consecutively arranged equalization zones (23) in each series (24) of the equalization zones (23) are spaced apart from each other by at least one cutting tooth (16).
3. The blade element according to claim 2, characterized in that, The series (24) having at least two equalization zones (23) is arranged at the polished surface (5, 9) in such a way that it is offset by an angle from the direction of the normal (N) of the longitudinal direction (LD) of the blade element (4, 8).
4. The blade element according to any one of the preceding claims, characterized in that, The blade elements (4, 8) have a specific intended orientation for mounting in the grinding mill (1), in which the blade teeth (16) and the grooves (17) are arranged at an angle relative to the intended rotational direction (RD) of the rotor (6) of the grinding mill (5) to facilitate the flow of the fibrous material toward the second end edge (19) of the blade elements (4, 8). The at least one equalization zone (23) is arranged at an angle relative to the intended rotation direction (RD) of the rotor (6) of the fine grinding mill (1) to prevent the fibrous material from flowing toward the second end edge (19) of the blade element (4, 8).
5. The blade element according to claim 1, characterized in that, At least one of the width and depth of the equalization zone (23) is arranged to decrease from the first end (23') of the equalization zone (23) toward the second end (23'') of the equalization zone (23) so that the volume of the equalization zone (23) decreases from the first end (23') of the equalization zone (23) toward the second end (23'') of the equalization zone (23).
6. The blade element according to claim 5, characterized in that, At least one of the width and depth of the equalization zone (23) is arranged to dynamically decrease from the first end (23') of the equalization zone (23) toward the second end (23'') of the equalization zone (23).
7. The blade element according to any one of claims 1-3, characterized in that, The volume of at least one equalization zone (23) that is closer to the second end edge (19) of the blade element (8) is arranged to be smaller than the volume of at least one other equalization zone (23) that is closer to the first end edge (19) of the blade element (4, 8).
8. The blade element according to any one of claims 1-3, characterized in that, The width of the cutting groove (17), which extends at least partially from the at least one equalization zone (23) toward the second end edge (19) of the blade element (4, 8), is arranged to increase in the direction from the first end (23') of the equalization zone (23) toward the second end (23'') of the equalization zone (23).
9. The blade element according to any one of claims 1-3, characterized in that, The blade elements (4, 8) are blade segments used to provide a portion of the complete grinding surface (5, 9) of the grinding elements (3, 6) of the grinding mill (1).
10. A fine grinding mill for finely grinding fibrous materials, characterized in that, The fine grinding mill (1) includes at least one blade element (4, 8) according to any one of claims 1 to 9.