Refiner plate for a refiner

Abstract

Refiner plate (18) for a refiner (10) having one or more rotors (16) rotatable about an axis of rotation and interacting with one or more stators (14) to mechanically treat a pulp containing cellulose fibers, wherein the refiner plates (18) are mountable on a rotor (16) or stator (14), the refiner plate (18) comprising: a base (22); and a plurality of spaced-apart refiner bars (30). At least some of the bars (30) are inclined with respect to the base (30) such that the front edge of the bars (30) is oriented substantially at an acute angle (31) of less than 90° with respect to the base (22), preferably at an acute angle (31) of 50° to 80° and most preferably at an acute angle (31) in the range of 60° to 70°.

Description

[0001] The present invention relates generally to a refiner filling for a refiner for processing cellulose material in the manufacture of paper, cardboard, fabric, towels or fiberboard products and, in particular, the rods of the refiner filling.

[0002] A rotary pulp refiner, which can be disc-shaped or conical, uses a replaceable refiner pack consisting of refiner plates mounted on one or more rotors and one or more stators to mechanically shear and compress cellulose fibers in a pulp suspension. The refiner plates can be single-piece (unit) components or composed of segments assembled together. The refiner plates have a multitude of refiner bars that perform the shearing and compression operations on the cellulose fibers in the pulp suspension. The spaces between the refiner bars in a plate form grooves through which the pulp suspension flows and is conveyed into gaps between the bars of opposing plates, where the refining process takes place.WO 2023 / 102642 discloses an embodiment of such a refiner with a refiner plate which may be a single component or may be formed from a plurality of refiner plate segments.

[0003] In some examples, the bars are spaced apart by means of spacers positioned between them. The bars and spacers are generally perpendicular to the refiner slot, or in other words, the bars extend essentially perpendicular to a base of the refiner plate.

[0004] In both disc-shaped and conical refiners, the presence of abrasives in the pulp suspension accelerates the wear of the refiner rods and the refiner filling, thereby reducing the depth of the grooves between adjacent rods. As a result, the refiner filling typically needs to be replaced relatively frequently.

[0005] Although it is known to apply a wear-resistant coating to the end face of the bars to extend their service life, this coating occupies a significant portion of the groove volume between the refiner bars, which in turn can reduce the hydraulic capacity of the refiner filling. WO 2023 / 102642 discloses a refiner plate with coatings.

[0006] In the prior art, various materials, geometries, and coating thicknesses for refiner rods have been considered; however, it remains desirable to provide refiner rods that offer a longer service life and lower energy consumption during operation. It is also advantageous to provide refiner rods with an improved leading-edge corner to enhance fiber pickup and thus improve the refinement process and the quality of the resulting fiber.

[0007] The object of the present invention is to provide an improved refiner and, in particular, an improved shape of the refiner rod, which offers a longer service life, lower energy consumption and improved pulp quality during operation of the refiner.

[0008] The invention solves the aforementioned problem by providing a refiner plate for a refiner with one or more rotors rotatable about an axis of rotation and interacting with one or more stators to mechanically treat pulp containing cellulose fibers, wherein the refiner plates are mountable on a rotor or stator, the refiner plate comprising: a base and a plurality of spaced-apart refiner bars, wherein at least some of the bars are inclined relative to the base such that the front faces of the bars are oriented substantially at an acute angle of less than 90° to the base, preferably at an acute angle of 50° to 80° and most preferably at an acute angle in the range of 60° to 70°. In general, embodiments of the present invention provide a refiner plate and a refiner in which the bars are inclined according to the claims (claim 1).The invention also solves the problem with a refiner with such refiner plates (claim 17).

[0009] According to the invention, at least some or all of the refiner rods are inclined. The inclined rods capture more fibers, resulting in more optimal fiber treatment, which in turn reduces energy consumption and thus overall rod wear. It is not necessary to replace the refiner plate as frequently as in the prior art. Furthermore, energy consumption is reduced due to the more efficient shearing process.

[0010] A preferred embodiment of the invention is characterized in that spacers are arranged between the rods and at least some of the spacers are inclined with respect to the base such that the spacers and the base are oriented substantially at an acute angle of less than 90° to each other, preferably at an acute angle of 50° to 80° and most preferably at an acute angle in the range of 60° to 70°. When both the rods and the spacers are inclined and oriented at an acute angle with respect to the base of the refiner plate, the arrangement is simple, efficient, and easy to manufacture. In this preferred embodiment, the rods and spacers are substantially parallel to each other.

[0011] According to another preferred embodiment, the rods and / or spacers are formed integrally with the base, resulting in a robust arrangement and a low risk of individual rods becoming loose or detaching from the base.

[0012] Furthermore, it is advantageous if the downward-facing sections of the rods are embedded in a solidified material, wherein the material is preferably a layer and / or consists of liquid epoxy resin, molten metal, or another liquid material that solidifies. This results in a strong bond.

[0013] In another alternative, preferred embodiment, not all rods would be inclined at the same angle. This has the advantage that the rods would be arranged at an optimal acute angle to the local tangential velocity. For example, the acute angle of rods located closer to the outer diameter of the refiner plate can be smaller than that of rods located closer to the inner diameter of the refiner plate. Another strategy that could be applied in this alternative, preferred embodiment would be to increase the variety of refiner operations by mixing the acute angles of the rods circumferentially. A pulp suspension contains fibers of varying lengths and diameters, and increased heterogeneity of fiber properties can have a positive effect on the properties of the processed pulp.

[0014] In another preferred embodiment, more than 10% of the bars have an angle of 90° with respect to the base. In other words, not all bars are inclined, but only a portion of the total number of bars. This leads to the aforementioned advantage that the optimal bar angle can be radially adapted to the local tangential velocity, or that a variety of refiner operations can be generated circumferentially. Bars with a 90° angle can also offer advantages from a structural or manufacturing perspective, as they are less expensive to produce or exhibit higher structural strength.

[0015] Another preferred embodiment is characterized in that the rods and / or spacers are attached to the base by soldering, welding, press fitting or gluing, since all these manufacturing processes are relatively simple and offer good strength.

[0016] Another preferred embodiment is characterized in that the rods and / or spacers have a trapezoidal cross-section, which results in a robust arrangement and is relatively easy to manufacture, for example by machining processes.

[0017] Furthermore, it is preferred that at least some of the aforementioned rods have a leading edge defined by an acute angle between the surrounding outer surface and the leading surface, the outermost surface of the rod preferably being oriented substantially parallel to the base. This embodiment is further developed by defining a trailing edge by an obtuse angle between the surrounding outer surface and the trailing surface.

[0018] Another preferred embodiment, which results in a robust arrangement, is characterized in that the rods are positioned and pressed and / or glued into slots formed in a slotted support plate, which can then serve as a base, the spacing of the slots defining the distance between the rods. Preferably, the rods can protrude upwards and downwards from the slotted support plate.

[0019] Preferably, the base, rods, and spacers are made of metal, and at least some of the refiner rods have a surface coated with a layer, preferably a layer with a variable thickness that varies along the rod length. Metal offers high strength, and the layer can improve the wear resistance of the refiner plate. According to a preferred embodiment, the base, rods, and spacers are made of different metals.

[0020] The foregoing is a simplified summary of the invention to provide a basic understanding of some aspects of it. This summary is not a complete overview of the invention. It is not intended to identify essential, central, or critical elements of the invention or to define its scope. Its sole purpose is to present some embodiments in simplified form as an introduction to the more detailed description below. Further aspects of the invention are defined in the claims and are described below with reference to the accompanying drawings, which: Fig. Figure 1 is a perspective view of a refiner with a rotor and a stator according to an embodiment of the present invention, showing the replacement of a segment of the refiner plate on the mounting surface of the stator. Fig. 2 is another perspective view of the refiner from Fig. Figure 1 shows the replacement of a segment of the refiner plate on the mounting surface of the rotor. Fig. Figure 3 is a sectional view of a refiner plate segment according to the state of the art. Fig. Figure 4 is a sectional view of a refiner plate segment according to an embodiment of the invention. Fig. Figure 5 is a sectional view of a refiner plate segment according to a further embodiment of the invention. Fig. Figure 6 is a sectional view of a refiner plate segment according to a further embodiment of the invention. Fig. Figure 7 is a sectional view of a refiner plate according to a further embodiment of the invention. Fig. Figure 8 is a sectional view of a refiner plate according to a further embodiment of the invention. Fig. Figure 9 is a sectional view of a refiner plate according to a further embodiment of the invention. Fig. Figure 10 shows a state-of-the-art arrangement, and Fig. Figure 11 shows an arrangement of the invention in operation.

[0021] Fig. Figure 1 is a perspective view of a refiner 10 according to an embodiment of the present invention. The refiner 10 has a housing 12, a stator 14, and a rotor 16 inside the housing 12. The rotor 16 is rotatable and rotates about an axis of rotation X during operation, interacting with the stator 14 to mechanically treat a pulp (or pulp suspension) containing cellulose fibers. The axis of rotation X defines an axial direction and a radial direction perpendicular to the axial direction X. In the Fig. In the embodiment shown in Figure 1, the refiner 10 is a disk-shaped refiner 10 with an interchangeable refiner plate 18, which has a refiner plate segment 20. Other types of refiners 10 can have the refiner plate 18 according to embodiments of the invention. A mounting surface is provided on each of the rotors 16 and stators 14. In some cases, an adapter plate is screwed to the mounting surface to accommodate smaller refiner plate segments. The refiner plate segments 20 typically have a base that receives the screws so that the refiner plate segment 20 can be screwed to the mounting surface.

[0022] It should be noted that all embodiments shown are examples of arrangements; however, the embodiments are not necessarily shown to scale or in the exact manufacturing dimensions. Rather, the dimensions can be varied, as is known to those skilled in the art.

[0023] The rods 30 (sometimes referred to as blades) can be joined to spacers 24 by welding or brazing to form a cluster, which is then welded to the base, and in some cases to a frame, to form the refiner plate segment. Alternatively, the rods 30 can be inserted into a slotted base and secured by welding, press fitting, bonding, or other means to form the cluster. In another option, the rods are inserted into a slotted carrier plate, as described below, and extended into a solidified medium that forms the base.

[0024] The complete refiner plate 18 preferably consists of a plurality of refiner plate segments 20, but the refiner plate 18 can also be a single-piece arrangement. In the example of Fig. 1. The refiner plate 18 consists of segments 20. A refiner plate 18 is generally a flat, annular, disc-like, or plate-like structure. It is understood that, according to alternative embodiments of the invention, the refiner plate 18 in a conical refiner may have a conical structure. The term "refiner plate 18" is to be understood as comprising a flat, disc-like plate with an arcuate segment 20 thereof, or a conical structure, or an angled segment thereof. In a disc-shaped refiner, the refiner plate may be a single circular plate or an annular plate comprising arcuate segments that are joined with other arcuate segments to form a complete circular or annular plate.In a conical refiner, the refiner plate can be a one-piece conical (or frustoconical) structure or a conical structure comprising angular segments of a cone (or frustoconical) that are assembled to form a complete conical (or frustoconical) structure. It is understood that a refiner plate can be circular, annular, or conical (i.e., defining a complete 360-degree component) or segmented (i.e., defining an arcuate or angular component of less than 360 degrees, designed to be assembled with other such segments to form a complete circular or annular plate, or, where appropriate, a cone).

[0025] Fig. Figure 1 shows the refiner plate 18 on the stator 14 and the replacement refiner segment 20. The refiner plate 20 can be attached to the stator 14 using fasteners, such as threaded screws or bolts, as shown. In this example, several refiner plate segments 20 are attached to the stator 14 in a ring-shaped arrangement to form a complete ring-shaped stator-side refiner plate 18. As shown in Fig. As shown in Figure 1, the stator 14 is attached to a door-like cover 15, which is pivotable about a hinge mechanism to allow the refiner plate(s) 20 to be replaced. The cover 15 interacts with the housing 12.

[0026] Fig. 2 is another perspective view of the refiner 10 from Fig. Figure 1 shows the refiner plate 18 on the rotor 16 and its replacement segment 20. The refiner plate segment 20 can be attached to the rotor 16 by fasteners, such as threaded screws or bolts, as shown. A plurality of refiner plate segments 20 are attached to the rotor 16 in an annular arrangement to form a complete annular rotor-side refiner plate 18. The rotor 16 is mounted within the housing 12 of the refiner 10 and is driven by a motor, preferably an electric motor. As mentioned above, the refiner plates 18 can be single-piece (unit) components or refiner plate segments 20 assembled to form a complete refiner plate, for example, an annular refiner plate 18. During refiner maintenance, the refiner plate 18 can be replaced when worn by exchanging the assembly of refiner plate segments 20 that form the complete plate 18. Fig. Figure 1 shows that the complete annular refiner plate 18 can be characterized by an inner diameter (ID) and an outer diameter (OD). The refiner plate thus extends radially from the inner diameter to the outer diameter. It is understood that a complete plate or ring can consist of arcuate or segmented filler pieces of different shapes.

[0027] As in the Fig. As shown in Figures 3-11, a refiner plate 18 has a base 22. In some embodiments, the base 22 may have a uniform thickness in the axial direction; alternatively, it may have a non-uniform thickness. The base 22 extends radially from an inner diameter ID to an outer diameter OD, as shown in Figure 3-11. Fig. Figure 1 shows that the refiner plates 18 have a plurality of refiner rods 30 which exert shear and compression effects on the cellulose fibers in the pulp suspension. The refiner bars 30 are located in the Fig. 3 and Fig. 10 refiner plates 18 shown according to the prior art and in particular the refiner plates 18 according to the invention, which are particularly in the Fig. Figures 4-9 and 11 show refiner bars 30 projecting from a base 22. In contrast to the prior art, for example disclosed in WO 2023 / 102642, the bars 30 or spacers 24 are perpendicular to a base 22, meaning that they extend substantially perpendicular to a base 22 of the refiner plate 18.

[0028] As in the Fig. As shown in Figures 4-9 and 11, the refiner plates 18 according to embodiments of the invention have a plurality of spaced refiner bars 30 (also referred to as "blades"). The bars 30 can be spaced with a uniform or non-uniform groove width, i.e., the distance between adjacent bars can vary or be constant. Preferably, the refiner bars 30 are spaced apart from one another by spacers 24. Each bar 30 is defined by a bar height BH, which generally projects axially from the base / spacer structure. The bar height BH can be constant or variable, with the variation occurring from stator to rotor, along the length of the groove, from groove to groove, or from one side of the groove to the other. In general, the bar height BH is in the range of 0.5 to 14.0 mm in the new condition and from 0 to 2.0 mm in the worn condition.In some implementations, the bar width BW can, for example, have a value in the range of 0.5 to 7.0 mm.

[0029] The Fig. Figures 4-9 and 11 show different embodiments of a refiner plate 18 with refiner bars 30 which are inclined and extend at an acute angle 31 with respect to the base 22 and / or the direction of the relative movement or direction of rotation (see in particular Figures 4-9 and 11). Fig. 11) The refiner rods 30 have a front surface 39 and a front edge 32, as well as a radially outwardly directed surface 36 and a rear surface 38 and a rear edge. In this context, front surface 39 and rear surface 38 refer to the direction of movement, in particular the direction shown in Fig. 11 shows the direction of rotation 52 of the refiner plate 18, or in relation to the direction of movement between the stator 14 and the rotor 16. The spaces between the refiner bars form grooves 34 through which the pulp suspension flows during operation and which flows into the gap between the radially outwardly directed surfaces 36 of the bars of the refiner plates on the rotor and stator.

[0030] As shown in the embodiments according to the invention, all or at least some of the rods 30 are inclined with respect to the base 22. Preferably, they are inclined such that the front surface 39 of the rods 30 is oriented substantially at an acute angle 31 of less than 90° with respect to the base 22 and / or its top surface, preferably at an acute angle of 50° to 80° and most preferably at an acute angle in the range of 60° to 70°.

[0031] The illustrations show that all or at least some of the rods 30 have a front surface 39 with a leading edge 32, which serves as an apex forming an acute angle 31 between the surrounding front surface and the outer surface of the rod. Preferably, the outer surface 36 of the rod is oriented substantially parallel to the base 22 or an outer surface of the base 22.

[0032] The rear surface 38 has a trailing edge which serves as a vertex and forms an obtuse angle 33 between the surrounding rear surface and outer surfaces of the rod 22.

[0033] As shown in the figures, it is advantageous that all or at least some of the spacers 24 are also inclined with respect to the base 22, such that the spacers 24 and the base 22 are oriented essentially at an acute angle 31 of less than 90° with respect to the base 22, preferably at an acute angle of 50° to 80°, and particularly preferably at an acute angle in the range of 60° to 70°. This results in a configuration in which the rods 30 and spacers 24 are essentially parallel to each other.

[0034] The rods 30 and / or spacers 24 are preferably attached to the base 22 by welding, soldering, press fitting, gluing, or other manufacturing processes. In an embodiment not shown, which also corresponds to the invention, the person skilled in the art will understand that it is also possible for the rods 30 and / or spacers 24 to be formed integrally within the base 22 or integrally with the base 22.

[0035] It is preferred that at least 10% of the bars have an angle of 90° with respect to the base 22. In the according to the Fig. In the embodiment shown in 4 - 9 and 11, all bars 30 form an acute angle 31 with respect to the base 22.

[0036] In the Fig. In the embodiment shown in Figure 4, the spacers 24 have a rectangular cross-section. A spacer cavity 35 is formed between the underside of a spacer 24 and the surface of the base 22. Since the lower section of each rod 30 also has a rectangular cross-section, a rod cavity 37 is formed between the underside of a rod 30 and the surface of the base 22.

[0037] In the Fig. In the embodiment shown in Figure 5, each spacer 24 has a trapezoidal cross-section, such that the underside of a spacer 24 is in contact with the top of the base 22. Since the lower section of each rod 30 has a rectangular cross-section, a rod cavity 37 is formed between the underside of a rod 30 and the surface of the base 22.

[0038] As from the in Fig. As can be seen in the exemplary embodiment shown in Figure 6, the rods 30 and the spacers 24 can have a trapezoidal cross-section. In this configuration, the undersides of both the spacers 24 and the rods 30 are in contact with the top surface of the base 22.

[0039] The cavities 35, 37 or contact surfaces between the rods 30 and / or the spacers 24 and / or the base 22 can be filled with an adhesive material or a filler or sealant material. This material can be, for example, an epoxy resin, a solidified liquid metal, or an elastopolymer that has transitioned from a liquid to a solid state.

[0040] As can be seen in particular from the configuration according to the in Fig. As can be seen in the embodiment shown in Figure 7, the rods 30 can be positioned in slots 40 formed in a slotted support plate 42, preferably attached to the base 22. The slots 40 run substantially parallel to each other and at an acute angle 31 of less than 90°, as shown in Figure 7. Fig. Figure 7 shows the rods 30 in relation to the base 22. Thus, the rods 30, whose lower sections are arranged in the slots 40, are also aligned at an acute angle 31 with respect to the support plate 42 and the base 22. A trailing edge defined by the rear surface 38 and the outer surface of the rods 30 is the apex of an acute angle of less than 90°, which in this example is equal to angle 31, preferably in the range of 50° to 80° and most preferably with an acute angle 31 in the range of 60° to 70°. Preferably, the support plate 42 is screwed, welded, or bonded to the base 22. The rods 30 are preferably pressed and / or bonded into the slots 40 formed in the slotted support plate 42 attached to the base 22. The distance D of the slot spacing 40 defines the distance of the bars 30.

[0041] The in Fig. The embodiment shown in 8 essentially corresponds to the embodiment in Fig. 7, with the difference that in Fig. 8 The rods 30 extend both upwards and downwards from the slotted support plate 42. The downwardly projecting sections or extensions of the rods 30 are embedded in a solidified material, preferably an epoxy resin or solidified molten metal layer 43, which fixes the rods 30 and reinforces the overall structure of the refiner plate 18.

[0042] In the Fig. In the embodiment shown in Figure 9, the rods 30 are positioned relative to the spacers 24 and the base 22 as in the prior art embodiment. Fig. 3 arranged, however, the rods 30 are bent over a portion of their length extending beyond the spacers 24 to form the acute angle 31. Thus, the rod need not have a simple rectangular cross-section, and the height of the exposed rod is crucial for the improved effect of the invention.

[0043] Fig. Figure 10 shows the complete configuration with a state-of-the-art configuration showing the direction of rotation of the rotor relative to the stator and the gap 50 between the opposing, radially outward-facing surfaces 36 of the bars 30.

[0044] Fig. Figure 11 shows the complete configuration, with the bars 30 arranged at an acute angle 31 to the base 22, and the bars 30 achieving the improved shear and refiner effects due to the rotation of the rotor 16 and in cooperation with the stator 14.

[0045] Preferably the base 20, the rods 30, the spacers 24, and the support plate 42 are made of metal.

[0046] Since this is not shown in detail, all described embodiments of the invention can be configured such that at least some of the refiner rods have a surface coated with a coating, preferably a coating with a variable thickness that varies along the rod height. For details of the coating, reference is made to the applicant's WO 2023 / 102642, the disclosure of which is incorporated in full into this application by reference. A variable coating has a thickness that varies either along the height of the refiner rod (e.g., from the base to the top of the rod) or in a radial direction (e.g., from the inner diameter ID to the outer diameter OD of the filling, see [reference]). Fig. 1) is variable.

[0047] This invention has been described with reference to specific embodiments, implementations, and configurations, which are intended to serve only as examples. Those skilled in the art will recognize that many obvious variations, refinements, and modifications can be made without departing from the inventive concept(s) set forth in this application. The scope of the exclusive right claimed by the applicant is therefore to be limited solely by the attached claims. Reference symbol: 10 refiners 12 cases 14 Stator 15 Cover 16 Rotor 18 Refiner plate 20 refiner plate segment 22 base 24 spacers 30 refiner rods 31 acute angle 32 edge 33 obtuse angle 34 Nut 35 spacer cavity 36 area 37 Rod cavity 38 rear surface 39 front surface 40 slots 42 slotted carrier plate 43 consolidated layer 50 gap 52 Direction of rotation ID inner diameter OD outer diameter X axis of rotation Bra bar height BW staff width D distance QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 2023 / 102642 [0002, 0005, 0027, 0046]

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