Bottom plate with tapered opening for pulp processing unit

Abstract

A base plate for a pulp processing unit includes a plate having an upper axial surface, a lower axial surface, and a plurality of openings extending through the plate from the upper axial surface to the lower axial surface. Each of the plurality of openings has a shape, a size, and an angle. The shape is a cross-sectional shape, a size equal to a maximum cross-sectional dimension, and the angle is an angle formed between a center line of each of the plurality of openings and an axial line parallel to a center axis of the base plate. The shape, size, orientation of shape, angle, or combination thereof of the plurality of openings varies depending on the position of the openings on the base plate. The invention further discloses a paper pulp processing unit comprising the bottom plate.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 593,018, filed October 25, 2023, entitled “Base Plate with Gradual Opening for Pulp Processing Unit,” and U.S. Provisional Patent Application No. 63 / 669,817, filed July 11, 2024, entitled “Base Plate with Gradual Opening for Pulp Processing Unit,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] This specification generally relates to pulp processing units for processing fibers, such as wood fibers, and specifically to base plates for pulp processing units. Background Technology

[0004] In the paper industry, the process of manufacturing paper includes producing pulp, which is a solid suspension of fibers, such as cellulose fibers or other fibers. Depending on the source of the fibers, pulp can include pulp fibers of various concentrations and sizes, as well as solid contaminants such as wood chips, fiber bundles, metal flakes, hardened binders, or other contaminants. The increasing use of recycled paper as a fiber source may increase the presence of hardened binders, metal chips, and wood chips in the pulp. Pulp production typically involves processing the pulp in a pulp processing unit, such as, but not limited to, pulpers, desanders, or other specialized pulp processing equipment. During pulp processing, the pulp source is combined with water in the pulp processing unit, which may be operated to hydrate and classify pulp fibers, remove at least a portion of solid contaminants from the pulp, or a combination of these operations. Summary of the Invention

[0005] During operation of a pulp processing unit (such as a pulper, desander, or other specialized pulp processing equipment) with a conventional base plate and rotors, the conventional base plate achieves filtration and / or separation of larger contaminants via openings of constant size and shape. During operation, the conventional base plate is stationary, while the rotors rotate about their common central axis very close to the conventional base plate. The rotors generate positive and negative pressure pulses, causing the fibrous pulp to vortex through the openings in the base plate. The openings in the base plate control the flow of pulp between the pulper container and the extraction chamber located below the base plate.

[0006] The constant size and shape of openings in conventional base plates is a drawback because, despite having the same size and shape, flow conditions near each opening vary significantly across the surface of a conventional base plate. For example, the fluid pressure around the rotor blades varies with radial distance from the rotor's central axis, which in turn alters the fluid velocity through the base plate openings, as will be discussed herein. Furthermore, the proximity of the openings in the base plate to the wear strips, which can connect to the upper axial surface of the base plate, further influences flow conditions. Failing to consider this variability in flow conditions when designing base plate openings limits the performance of conventional base plates in terms of through flow, backflow, and contaminant removal.

[0007] Therefore, there is a persistent need for a base plate capable of adapting to different flow conditions at different locations on its surface. This disclosure relates to a base plate whose openings vary in size, shape, orientation, or combination thereof based on their location on the base plate. Openings through the base plate can vary in size, shape, orientation, or combination thereof, depending on their position relative to the wear strip, their radial position relative to the center of the base plate, or a combination of both. Variations in the size, shape, and / or orientation of openings in the base plate refer to openings within the working area of ​​the base plate, the area traversed by the rotor. Variations in the size, shape, and / or orientation of openings in the base plate allow for design based on local flow conditions at the upper axial surface of the base plate. These local flow conditions can vary significantly based on radial distance from the center of the base plate and / or the position of the opening relative to the wear strip. Adapting the size, shape, and / or orientation of the base plate openings to flow conditions improves the throughflow, backflow, and solid contaminant removal performance of each individual opening, which can improve the overall performance and efficiency of the base plate.

[0008] According to an aspect of this disclosure, a base plate for a pulp processing unit includes a plate having an upper axial surface, a lower axial surface, and a plurality of openings extending through the plate from the upper axial surface to the lower axial surface. Each of the plurality of openings may have a shape, size, and angle, wherein the shape is a cross-sectional shape in a plane parallel to the central axis of the base plate, the size is equal to the maximum cross-sectional dimension, and the angle is the angle formed between the centerline of each of the plurality of openings and the axial line parallel to the central axis of the base plate. The shape, size, orientation of the shape, angle, or any combination thereof of the plurality of openings may vary depending on the position of the openings on the base plate.

[0009] According to other aspects of this disclosure, a pulp processing unit for processing pulp stock may include a base plate according to any aspect of this disclosure. The pulp processing unit may also include a container and a rotor. The base plate may be arranged such that its upper axial surface faces the rotor.

[0010] It should be understood that both the conventional implementation described above and the specific implementation described below describe various embodiments and are intended to provide an overview or framework for understanding the nature and characteristics of the claimed subject matter. Attached Figure Description

[0011] The accompanying drawings are included to provide a further understanding of the various embodiments, and are incorporated in and constitute a part of this specification. The drawings illustrate the various embodiments described herein and, together with the specification, serve to explain the principles and operation of the claimed subject matter.

[0012] Figure 1 A front partial sectional perspective view of a pulp processing unit including a pulper for processing wood fibers is schematically depicted according to the embodiments shown and described herein. Figure 2 The embodiments illustrated and described herein are schematically depicted. Figure 1 A front sectional view of the pulper rotor; Figure 3 A top view of a conventional base plate is schematically depicted based on existing technology; Figure 4 Based on the existing technology, it is schematically depicted Figure 3 A sectional view of the standard base plate; Figure 5 The embodiments illustrated and described herein are schematically depicted for... Figure 2 Modeling of the fluid velocity as the rotor blades of a pulper pass through a bottom plate containing multiple equal-sized openings; Figure 6 The embodiments shown and described herein depict when Figure 2 Computational fluid dynamics (CFD) modeling of transient (e.g., time-dependent) fluid pressure near the wear-resistant strips on a plate when the rotor blades of a pulper rotor pass over the plate; Figure 7 A rotor blade in a first position on the high-pressure side relative to a wear-resistant strip attached to a flat plate is schematically depicted according to the embodiments shown and described herein; Figure 8 The embodiments illustrated and described herein are schematically depicted. Figure 7 The rotor blades are in a second position relative to the wear-resistant strip on the flat plate, where the second position corresponds to... Figure 9 The relatively low isobaric line at the point on the low-pressure side of the wear-resistant strip; Figure 9 The fluid pressure (y-axis) as a function of time (x-axis) on the high-pressure side and low-pressure side of the wear strip is graphically depicted according to the embodiments shown and described herein. Figure 10A top view of a base plate is schematically depicted according to the embodiments shown and described herein, the base plate having an opening size that changes from the high-pressure side of the wear strip to the low-pressure side of the adjacent wear strip; Figure 11 The embodiments illustrated and described herein are schematically depicted. Figure 10 A side sectional view of a portion of the base plate; Figure 12 A top view of a base plate without wear strips and having an opening whose size changes in the angular direction is schematically depicted according to the embodiments shown and described herein; Figure 13 A top view of a base plate is schematically depicted according to the embodiments shown and described herein, the base plate having an opening, wherein the size of the opening varies with radial distance from the center of the base plate; Figure 14 A top view of a base plate without wear strips and having an opening whose size varies with radial distance from the center of the base plate, according to the embodiments shown and described herein; Figure 15 A top view of the base plate is schematically depicted according to the embodiments shown and described herein, wherein the size of the opening varies based on its radial position relative to the center of the base plate and its angular direction relative to the wear strip; Figure 16 A top view of a base plate is schematically depicted according to the embodiments shown and described herein, the base plate having an opening whose shape changes with radial distance from the center of the base plate; Figure 17 A top view of a base plate is schematically depicted according to the embodiments shown and described herein, the base plate having an opening whose shape changes based on the angular position of the opening relative to the wear strip; Figure 18 A top view of a base plate is schematically depicted according to the embodiments shown and described herein, the base plate having openings of the same shape and size but whose orientation changes with the radial distance from the center of the base plate; Figure 19 A side sectional view of a portion of a base plate, having an opening extending through a wear-resistant strip, is schematically depicted according to the embodiments shown and described herein. Figure 20 A side sectional view of a portion of a base plate is schematically depicted according to the embodiments shown and described herein, the base plate having an opening angled relative to a line perpendicular to the upper axial surface of the base plate, wherein the opening is angled toward the low-pressure side of the wear strip in the angular direction. Figure 21 A side sectional view of a portion of a base plate is schematically depicted according to the embodiments shown and described herein, the base plate having a high-pressure side facing the wear-resistant strip in an angular direction (i.e., with...). Figure 20 An opening at an angle (relative angle and direction); Figure 22 A side sectional view of a portion of a base plate is schematically depicted according to the embodiments shown and described herein, the base plate having an opening angled relative to a line perpendicular to the upper axial surface of the base plate, wherein the opening is angled in the radially increasing direction; Figure 23 A side sectional view of a portion of a base plate is schematically depicted according to the embodiments shown and described herein, the base plate having a radially decreasing direction (i.e., with respect to...). Figure 22 An angled opening in the relative radial direction; Figure 24 A side sectional view of a portion of a base plate is schematically depicted according to the embodiments shown and described herein, the base plate having an angled opening whose size changes in the angular direction; Figure 25 A side sectional view of a portion of a base plate is schematically depicted according to the embodiments shown and described herein, the base plate having an angled opening whose size changes in the radial direction; Figure 26 A side sectional view of a portion of a base plate is schematically depicted according to the embodiments shown and described herein, the base plate having an opening that changes angle relative to a line perpendicular to the upper axial surface of the base plate; Figure 27 A side sectional view of another embodiment of a base plate, having an opening that changes angle relative to a line perpendicular to the upper axial surface of the base plate, is schematically depicted according to the embodiments shown and described herein. Figure 28 A side sectional view of a portion of a base plate is schematically depicted according to the embodiments shown and described herein, the base plate having an opening whose angle and size change relative to an angular direction; Figure 29 A side sectional view of a portion of a base plate, having an opening, is schematically depicted according to the embodiments shown and described herein, wherein the size of the opening angle increases with increasing radial direction; Figure 30 A side sectional view of a portion of a base plate, having an opening, is schematically depicted according to the embodiments shown and described herein, wherein the size of the opening angle increases as the radial direction decreases; Figure 31 A side sectional view of a portion of a base plate is schematically depicted according to the embodiments shown and described herein, the base plate having an opening, wherein the chamfers at both ends of the opening change as the position on the base plate changes; Figure 32 A top view of a base plate is schematically depicted according to the embodiments shown and described herein, the base plate having an opening in the form of a slot, the size of which changes with the radial position on the base plate; Figure 33A top view of a base plate is schematically depicted according to embodiments shown and described herein, the base plate having a slotted opening whose size varies with radial and / or angular position on the base plate; and Figure 34 A top view of a base plate is schematically depicted according to the embodiments shown and described herein, the base plate having an opening in the form of a slot, wherein the orientation of the slot changes as its position on the base plate changes. Detailed Implementation

[0013] Reference will now be made in detail to embodiments of this disclosure, examples of which are illustrated in the accompanying drawings. Where possible, the same reference numerals are used throughout the drawings to refer to the same or similar parts. Reference Figure 1 and Figure 2 The base plate 120 for the pulp processing unit 100 may include a flat plate 122, which includes an upper axial surface 124, a lower axial surface 126, and a plurality of openings 130 extending through the flat plate 122 from the upper axial surface 124 to the lower axial surface 126. The base plate 120 may also include a plurality of abrasion-resistant strips 140 extending outward from the upper axial surface 124 of the base plate 120. Each of the plurality of openings 130 may have a shape, size, and orientation, wherein the shape is a cross-sectional shape and the size is equal to the largest cross-sectional dimension. The shape, size, orientation, or combination thereof of each of the plurality of openings 130 may vary depending on the position of the openings 130 on the base plate 120.

[0014] Unless otherwise expressly stated, no method described herein is intended to require its steps to be performed in a specific order, nor is any device intended to have a specific orientation. Therefore, if a method claim does not actually list the order in which its steps are to be followed, or any device claim does not actually list the order or orientation of the various components, or the claims or description do not otherwise specifically state that the steps are limited to a specific order, or do not describe a specific order or orientation of the device components, then no order or orientation is intended to be inferred in any way. This applies to any possible non-express basis of interpretation, including: logical matters concerning the arrangement of steps, the flow of operations, the order of components, or the orientation of components; general meanings derived from grammatical organization or punctuation; and the number or type of embodiments described in the specification.

[0015] The directional terms used in this article—such as up, down, left, right, front, back, top, bottom—are used only with reference to the accompanying drawings and the coordinate axes provided, and are not intended to imply absolute orientation.

[0016] As used herein, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly indicates otherwise. Thus, for example, reference to a component “a” includes aspects having two or more such components, unless the context clearly indicates otherwise.

[0017] As used in this article, the terms "longitudinal" and "axial" refer to an orientation or direction that is generally parallel to the central axis A of the pulper rotor.

[0018] As used herein, the term “radial” refers to the direction along any radial line extending outward from the central axis A of the pulper rotor or from the center of the base plate.

[0019] As used herein, the terms “forward” and “backward” refer to the position or orientation of an object relative to the direction of its motion; “forward” means toward the direction of motion, and “backward” means away from the direction of motion. The term “leading edge” for rotor blades disclosed herein refers to the edge of the rotor blade facing the direction of rotation of the pulper rotor, and the term “trailing edge” refers to the edge of the rotor blade facing the direction opposite to the direction of rotation of the pulper rotor.

[0020] As used herein, the term "inner side" refers to the radial direction toward the central axis A of the pulper rotor, and the term "outer side" refers to the radial direction away from the central axis A of the pulper rotor.

[0021] Now for reference Figure 1 The illustration schematically depicts one embodiment of a pulp processing unit 100 for processing pulp. The pulp processing unit 100 is in... Figure 1 The unit is depicted as a pulper, and the embodiments disclosed herein are described in the context of a pulper. However, the base plate embodiments disclosed herein can be used in other types of pulp processing units 100, such as, but not limited to, desanders or other specialized pulp processing equipment, and have similar expectations of success. The pulp processing unit 100 may include a container 102 and a rotor assembly 104 disposed at the bottom of the container 102. The rotor assembly 104 may include a rotor 105, which includes a plurality of rotor blades 106 extending radially outward from the center of the rotor 105. The rotor assembly 104 may also include a rotor cover 109. The rotor assembly 104 may also include a cover disposed vertically below the rotor blades 106 (i.e., along...). Figure 1 The base plate 120 (in the -Z direction of the coordinate axis).

[0022] Now for reference Figure 2 The rotor assembly 104 may further include a rotor shaft 110. The rotor shaft 110 may be rigidly coupled to the rotor 105 at one end and to a rotor driver (not shown) at the other end. The rotor driver can rotate the rotor shaft 110, which in turn can rotate the rotor 106. A rotor cover 109 may be coupled to the top of the rotor 105 and can protect the bearings of the rotor assembly 104 from the intrusion of liquids and fibers from the pulp slurry in the container 102 during operation. In an embodiment, each rotor blade 106 may have a rotor abrasion strip 141, which extends vertically downwards from the bottom surface of each rotor blade 106 (i.e., along...). Figure 2Extending in the -Z direction of the coordinate axis. In an embodiment, the rotor blade 106 may not include the rotor wear strip 141.

[0023] Refer again Figure 2 The base plate 120 can be positioned vertically below the rotor 105 (i.e., along...). Figure 2 The base plate 120 (in the -Z direction of the coordinate axis) can be spaced apart from the rotor 105. The base plate 120 can be stationary and disengaged from the rotor 105, allowing the rotor 105 to rotate relative to the base plate 120 during operation. The base plate 120 can include a flat plate 122 having an upper axial surface 124 and a lower axial surface 126. The upper axial surface 124 of the base plate 120 can be spaced apart from the bottom surface of the rotor 105 to form a gap G between the base plate 120 and the rotor 105. In one embodiment, the base plate 120 can include a plurality of wear-resistant strips 140 extending generally outward from the center of the base plate toward the outer edge of the base plate 120. In another embodiment, the base plate 120 does not include wear-resistant strips.

[0024] refer to Figure 1 and Figure 2 The base plate 120 may include a plurality of openings 130. The openings 130 extend axially through the plate 122 from the upper axial surface 124 to the lower axial surface 126. The axial direction refers to the direction parallel to the central axis A of the rotor assembly 104 (i.e., parallel to...). Figure 1 and Figure 2 (The direction of the + / -Z direction of the coordinate axis).

[0025] Refer again Figure 1 and Figure 2 The pulp processing unit 100 may further include an extraction chamber 112, which is located vertically below the base plate 120 (i.e., along the...). Figure 2 The base plate 120 is positioned between the rotor 105 and the extraction chamber 112 (in the -Z direction of the coordinate axis), such that the base plate 120 is positioned between the rotor 105 and the extraction chamber 112. The extraction chamber 112 may be an annular cavity in fluid communication with an opening 130 in the base plate 120. The extraction chamber 112 may also be in fluid communication with a fiber outlet 114 for the pulp. During operation of the pulp processing unit 100, the pulp fibers processed in the gap G between the rotor blades 106 and the base plate 120 pass through the opening 130 in the base plate 120 into the extraction chamber 112. The pulp fibers then pass through the extraction chamber 112 to the pulp fiber outlet 114. The pulp fibers can then be output from the pulp processing unit 100 to one or more downstream operations for further processing in the upstream of the papermaking process.

[0026] Refer again Figure 1The pulp processing unit 100 may also include a waste outlet 116, which is in fluid communication with the internal volume of the container 102. The waste outlet 116 provides an outlet for removing solid contaminants and excessive pulp fibers from the pulp processing unit 100.

[0027] Refer again Figure 1 and Figure 2 During operation of the pulp processing unit 100, a pulp source (e.g., wood pulp, recycled paper, or other fiber source) and water can be introduced into container 102 from the top 103. A rotor 105 rotates relative to a base plate 120. The rotation of the rotor 105 can be operated to agitate the contents of container 102 to produce pulp. During the rotation of the rotor 105, a portion of the pulp may seep into the gap G between the stationary base plate 120 and the rotating rotor 105. Shear forces in the gap G between the rotor 105 and the base plate 120 can process the fibers, for example, by separating fiber aggregates into individual fibers, breaking down the fibers, or other treatments. A portion of the pulpable fibers and water then enters the extraction chamber 112 through an opening 130 in the base plate 120. The pulpable pulp travels through the extraction chamber 112 to the pulp-forming fiber outlet 114. The centrifugal force from the rotating rotor 105 may cause heavier fibers, fiber aggregates, debris, etc. to travel radially outward away from the gap G between the bottom plate 120 and the rotor 105, and return to the container 102 or to the fiber outlet 116 where waste is discharged.

[0028] Now for reference Figure 3 The diagram schematically depicts a top view of a conventional base plate 20. The conventional base plate 20 typically includes multiple wear-resistant strips 40 connected to the upper axial surface 24 of the base plate 20. The conventional base plate 20 has a working area 36 and a non-working area 38. The working area 36 is the region of the conventional base plate 20 over which the rotor 105 rotates during operation of the pulp processing unit 100. Since the diameter of the conventional base plate 20 is typically larger than the outer diameter of the rotor 105, the conventional base plate 20 may include a non-working area 38, which is the peripheral region of the conventional base plate 20 over which the rotor blades 106 of the rotor 105 do not pass. The non-working area 38 is an annular region disposed between the working area 136 and the outer circumference 29 of the conventional base plate 20.

[0029] refer to Figure 3 and Figure 4The conventional base plate 20 has openings 30 extending through the thickness of the conventional base plate 20 from the upper axial surface 24 to the lower axial surface 26. For the conventional base plate 20, the openings 30 in the working area 36 of the base plate are generally uniform, having the same shape, size, and orientation. The same size means that all openings 30 have the same cross-sectional area. The openings 30 can be circular, polygonal, or irregularly shaped. Typically, all openings 30 in the working area 36 of the conventional base plate 20 have the same shape, size, and orientation.

[0030] During pulper operation with a conventional base plate 20, filtration and / or separation of larger contaminants by the conventional base plate 20 is achieved via openings 30 of constant size and shape. During operation, the conventional base plate 20 is stationary, and the rotors rotate about their common central axis A very close to the conventional base plate 20. Otherwise, the process would stop almost immediately due to fibrous pulp and contaminants clogging the openings 30. The rotors generate positive and negative pressure pulses and cause vortex flow of fibrous pulp through openings parallel to the axial surface 24 on the conventional base plate 20. The positive and negative pressure pulses are significantly affected by the local linear velocity of the rotor 105. The local linear velocity of each rotor blade 106 and a point on rotor blade 106 increases as that point moves radially outward from the central axis A, for example from the inner end to the outer end of rotor blade 106. The magnitudes of the positive and negative pressure pulses are approximately proportional to the square of the radius. According to Equation 1 (EQU.1), the linear velocity (V) at any point on rotor blade 106 is equal to the rotational speed (ω) multiplied by the radius (r).

[0031] Equation 1

[0032] According to Equation 2 (EQU.2), the fluid pressure (P) is approximately proportional to the square of the linear velocity.

[0033] Equation 2

[0034] In Equation 2, P is the magnitude of the fluid pressure, V is the linear velocity at a point on rotor blade 106, r is the radius at that point on rotor blade 106, ω is the rotational speed in radians per time, and ρ is the density of the fiber slurry.

[0035] Now for reference Figure 5 Rotor blade 106 passes through Figure 3 and Figure 4 CFD modeling of the fluid velocity during operation on the upper axial surface 24 of a conventional base plate 20 with an opening 30 of constant shape and size. The direction of motion of the rotor blades 106 is indicated by arrow 118. Figure 5This illustrates the fluid flow of pulp slurry flowing downwards through an opening 30 in a conventional base plate 20 into an extraction chamber 112 located below the conventional base plate 20 near the leading edge 107 of the rotor blades 106. The pulp slurry can flow upwards from the extraction chamber 112 back into the container 102 through the opening 30 in the conventional base plate 20 (backflow). The term "throughflow" refers to the flow of pulp slurry from the container through the opening into the extraction chamber. The term "backflow" refers to the flow of pulp slurry upwards from the extraction chamber back into the container through the opening. Figure 5 As shown, the opening 30 in the conventional base plate 20 controls the flow of pulp between the container 102 and the extraction chamber 112. Figure 5 It is also shown that the flow conditions near the opening 30 change significantly as the rotor blade 106 passes over the upper axial surface 124 of the conventional base plate 20.

[0036] The constant size, shape, and orientation of the openings 30 in the conventional base plate 20 is a drawback because, despite having the same size and shape, the flow conditions near each opening 30 vary significantly on the surface of the conventional base plate 20. Failing to consider this variability in flow conditions when designing the openings 30 of the conventional base plate 20 limits its performance in terms of through flow, backflow, and contaminant removal.

[0037] For example, as previously described, the fluid pressure at the leading edge 107 of rotor blade 106 varies with the radial distance from the central axis A of rotor 105, which in turn alters the fluid velocity. As discussed in Equations 1 and 2, the fluid pressure is proportional to the square of the linear velocity of rotor blade 106, which in turn depends on the radial distance (radius r) from the center of rotor 105. Therefore, as the radius increases, the magnitude of the fluid pressure increases, and the fluid velocity through the orifice (both through flow and backflow) increases. For a constant opening 30, the performance of the conventional base plate 20 for grading pulp fibers and removing solid contaminants will vary with the radius from the center, resulting in low efficiency.

[0038] Furthermore, the opening in the base plate near the wear-resistant strip further affects flow conditions. (See reference now.) Figure 6 The fluid pressure generated by the rotor blade 106 passing over the wear-resistant strips 140 on the surface of the plate 160 is modeled. Figure 6 Arrow 118 indicates this. The wear-resistant strip 140 has a high-pressure side 142 and a low-pressure side 144. During the passage of the rotor blade 106 through the wear-resistant strip 140, the rotor blade 106 first encounters the high-pressure side 142 of the wear-resistant strip 140, and then encounters the low-pressure side 144. (As shown...) Figure 6 As shown, the fluid pressure on the upper surface of plate 160 is greatest at the high-pressure side 142 of the wear-resistant strip and much lower at the low-pressure side 144 of the wear-resistant strip 140.

[0039] Because the fluid velocity through the openings in the bottom plate is dependent on fluid pressure, the higher pressure on the high-pressure side of the abrasion strip increases the flow velocity of the pulp entering the extraction chamber through the openings in the bottom plate. Similarly, the lower pressure on the low-pressure side of the abrasion strip reduces the flow velocity or causes the pulp to flow back up from the extraction chamber into the container through the openings. Figure 6 and Figure 5 When comparing the fluid velocities, it is clear that as the rotor blades 106 pass over the abrasion strips 140, the presence of the abrasion strips significantly affects the flow pattern of the pulp. Figure 5 In the conventional base plate 20, the flow velocity through the opening 30 is maximum at the leading edge 107 of the rotor blade 106. However, as... Figure 6 As shown, as rotor blade 106 passes through wear-resistant strip 140, the leading edge 107 passes through the low-pressure side 144 of wear-resistant strip 140, which causes a decrease in fluid pressure at the leading edge 107. Therefore, as rotor blade 107 passes through wear-resistant strip 140, the maximum pressure is actually closer to the trailing edge 108 of rotor blade 106 than to the leading edge 107, which alters the normal flow pattern generated by the rotation of rotor blade 106.

[0040] refer to Figure 7-9 Modeling was performed on the rotor blades 106 sequentially passing through the wear-resistant strips 140 attached to the flat plate 140. Figure 7 In the middle, the rotor blade 106 is located at the high-pressure side 142 of the wear-resistant strip 140, in Figure 8 In the middle, most of the rotor blades 106 have passed the wear-resistant strips. As the rotor blades 106 move towards the wear-resistant strips (such as...), Figure 7 (in the middle), above the wear-resistant strip, and then past the wear-resistant strip (such as...) Figure 8 As shown in the diagram, the pressure at point 162 is modeled as a function of time. Now refer to... Figure 9 The high-pressure side of the wear-resistant strip is depicted graphically. Figure 8 and Figure 9 The pressure (y-axis) at point 162 (reference numeral 802) and the low-pressure side of the wear-resistant strip (reference numeral 804) is taken as a function of time (x-axis). Figure 9 As shown, the pressure on the high-pressure side of the wear-resistant strip reaches its maximum value, which corresponds to... Figure 7 Position of rotor blade 106. Figure 9 This demonstrates how much the flow conditions can change as the rotor blades 106 pass over the abrasion strips 140 on the substrate. A conventional substrate 20 with openings 30 of constant size, shape, and / or orientation does not account for the differences in flow conditions caused by the abrasion strips 140, thus introducing additional inefficiencies to the pulp fiber classification and / or solid contaminant removal performance of the conventional substrate 20 near the abrasion strips 140.

[0041] Now for reference Figure 10This disclosure relates to a base plate 120 having an opening 130, the opening 130 varying in size, shape, orientation, or a combination thereof based on its location on the base plate 120. The opening 130 through the base plate 120 can vary in size, shape, orientation, or a combination thereof depending on the position of the opening 130 relative to the wear strip 140, the radial position of the opening 130 relative to the center 128 of the base plate 120, or a combination of both. Variations in the size, shape, and / or orientation of the opening 130 in the base plate 120 refer to the opening 130 in the working area 136 of the base plate 120, and are not intended to include any openings in the non-working area 138 of the base plate 120, which is the portion of the base plate 120 extending radially outward beyond the outer end of the rotor blade 106.

[0042] Varying the size, shape, orientation, or combination thereof of the openings 130 in the base plate 120 allows the size, shape, and / or orientation of the openings 130 to be designed based on local flow conditions at the axial surface 124 of the base plate 120. As previously mentioned, these local flow conditions can vary significantly based on radial distance from the center 128 of the base plate 120 or, when the wear strip 140 is present, relative to the position of the wear strip 140. Adapting the size, shape, and / or orientation of the openings 130 of the base plate 120 to the local flow conditions at each location can improve the throughflow, backflow, and solid contaminant removal performance of each individual opening 130, which can improve the overall performance and efficiency of the base plate 120.

[0043] The shape of opening 130 refers to the cross-sectional shape of the opening, where the cross-sectional shape is the shape of opening 130 in a plane perpendicular to the axial centerline of opening 130. The size of opening refers to the maximum cross-sectional dimension of the cross-sectional shape of opening 130. For example, for a cylindrical opening 130 with a circular cross-sectional shape, the size of opening refers to the diameter of the circular cross-section of opening 130. For an opening 130 with a polygonal cross-sectional shape, the size of opening 130 refers to the maximum diagonal distance of the cross-sectional shape. For an irregular cross-sectional shape, the size of opening 130 refers to the maximum cross-sectional dimension of opening 130. For an opening 130 that does not have a circular cross-sectional shape, the orientation of opening 130 refers to the rotational position of the cross-sectional shape relative to the axial centerline of opening 130. Variations in the size, shape, and / or orientation of opening 130 discussed herein refer to the size, shape, and / or orientation of opening 130 in the working area 136 of base plate 120 and are not intended to refer to any differences in size or shape of openings in the non-working area 138 of base plate 120. Figure 10-25 In the drawing, the relative size of the opening 130 is not drawn to scale and is exaggerated for illustrative purposes.

[0044] Refer again Figure 10The base plate 120 may include one or more wear-resistant strips 140, which are connected to the upper axial surface 124 of the base plate 120. The wear-resistant strips 140 extend axially toward the rotor 105. The base plate 120 may include two, three, four, five, six, or more than six wear-resistant strips 140. Each wear-resistant strip 140 may extend substantially radially outward from the center 128 of the base plate 120 (i.e., along...). Figure 11 The wear-resistant strip 104 extends towards the outer circumference 129 (in the +r direction of the coordinate axis). In an embodiment, the wear-resistant strip 140 can extend straight outward in the radial direction directly between the center 128 of the base plate 120 and the outer circumference 129. In an embodiment, the wear-resistant strip 140 can be angled or bent relative to the radial direction. The wear-resistant strip 104 can extend along the rotor 105 ( Figure 2 The wear-resistant strip 140 may be angled or bent relative to the direction of rotation of the rotor 105 or the direction of rotation of the rotor 105. In an embodiment, the wear-resistant strip 140 may be straight and angled relative to the radial direction.

[0045] The wear-resistant strip 140 has a high-pressure side 142 and a low-pressure side 144. The low-pressure side 144 of the wear-resistant strip 140 is the side of the wear-resistant strip 140 facing the rotor rotation direction 118. The high-pressure side 142 of the wear-resistant strip is the side of the wear-resistant strip 140 opposite to the low-pressure side 144. Rotor blade 106 ( Figure 1 and Figure 2 It encounters the high-pressure side 142 before passing the low-pressure side 144.

[0046] Refer again Figure 10 In an embodiment, the opening 130 in the working area 136 of the base plate 120 can vary in size based on its position relative to the abrasion strip 140. In an embodiment, the opening 130 near the high-pressure side 142 of the abrasion strip 140 can have a smaller size. Due to the increased pressure and fluid velocity at the high-pressure side 142 of the abrasion strip 140, reducing the size of the opening near the high-pressure side 142 can reduce the volumetric flow rate of pulp through the opening 130 near the high-pressure side 142 to accommodate the greater pressure and fluid velocity. Similarly, in an embodiment, the opening 130 near the low-pressure side 144 of the abrasion strip 140 can have a larger size. Due to the lower pressure, the fluid flow velocity through the opening 130 at the low-pressure side 144 is lower. Therefore, increasing the size of the opening 130 near the low-pressure side 144 can increase the volume of pulp flowing backward through the opening 130 to compensate for the reduced pressure and the resulting fluid velocity. Reducing the size of the opening 130 at the high-pressure side 142 of the wear-resistant strip 140 and increasing the size of the opening at the low-pressure side 144 can be relative to the angle (Setta, This improves the consistency and uniformity of the performance of the base plate 120, thereby improving the overall efficiency of the base plate 120.

[0047] In an embodiment, the size of the opening 130 can gradually increase from a minimum size at the high-pressure side 142 of a wear-resistant strip 140 to a maximum size at the low-pressure side 144 of an adjacent wear-resistant strip 140 in an angular direction opposite to the rotor rotation direction (i.e., along...). Figure 10 The middle coordinate axis - (-Setta) direction) adjacent. In Figure 10 In, + The direction is the same as the rotation direction 118 of the rotor. In the embodiment, at each radial distance from the center 128 of the base plate 120, the size of each of the plurality of openings 130 is relative to the angular position of each of the plurality of openings 130 (i.e., along the angular position of each of the plurality of openings 130). Figure 10 + / - of the middle coordinate axis The direction and position change.

[0048] Now for reference Figure 11 Schematic depiction Figure 10 A cross-sectional view of the base plate 120 between two wear-resistant strips 140 in the working area 136. In an embodiment, the size of each of the plurality of openings 130 may vary relative to the proximity of each of the plurality of openings 130 to the high-pressure side 142 of the wear-resistant strip 140. Figure 11 As shown, near the high-pressure side 142 of the wear-resistant strip 140, the opening 130 can have a smaller size, and with increasing distance from the high-pressure side 142 of the wear-resistant strip 140 in the angular direction (e.g., along...). Figure 11 The middle coordinate axis - As directional movement increases, the size of the opening (130°) can be increased. (Reference) Figure 11 The opening 130 in the base plate 120 may include a first opening 150 and a second opening 152, wherein the first opening 150 and the second opening 152 are located at the same radial distance from the center 128 of the base plate 120. The first opening 150 may have a first angular position relative to the reference wear-resistant strip 140, and the second opening 152 may have a second angular position relative to the reference wear-resistant strip 140. The first opening 150 may have a different size than the second opening 152. The absolute value of the size difference between the first opening 150 and the second opening 152 may be greater than the manufacturing tolerance of the opening 130, for example, greater than or equal to 5%, greater than or equal to 10%, greater than or equal to 15%, greater than or equal to 20%, or even greater than or equal to 25% of the size of the smaller of the first opening 150 and the second opening 152.

[0049] Refer again Figure 11 The wear-resistant strip 140 has a high-pressure side 142 and a low-pressure side 144, and the base plate 120 may include a first opening 150 near the high-pressure side 142 of one of the wear-resistant strips 140 and an angle direction (i.e., along) relative to the first opening 150. Figure 11 The middle coordinate axis - A second opening 152, located further away from the high-voltage side 142 (direction). In an embodiment, the first opening 150 may have a smaller size than the second opening 152. Figure 11 As shown, the smaller size of the first opening 150 near the high-pressure side 142 of the wear-resistant strip 140 can restrict the flow 170 from the upper axial surface 124 to the lower axial surface 126 through the first opening 150. Figure 11 As shown, when the rotor blade 106 is passing over the wear-resistant strip 140, the smaller size of the first opening 150 and the larger size of the second opening 152 may restrict the flow 170 from the upper axial surface 124 to the lower axial surface 126 through the first opening 150, and cause the backflow 172 from the lower axial surface 126 to the upper axial surface 124 through the second opening 152. Due to the higher pressure at the high-pressure side 142 of the wear-resistant strip 140, restricting the flow 170 through the first opening 150 improves the separation efficiency of the base plate 120 at the high-pressure side 142 of the wear-resistant strip 140.

[0050] Refer again Figure 10 and Figure 11 In an embodiment, each wear-resistant strip 140 includes a high-pressure side 142 and a low-pressure side 144, and at each radial distance from the center 128 of the base plate 120, the size of each of the plurality of openings 130 varies with the angular distance from the high-pressure side 142 of each wear-resistant strip 140 to the low-pressure side 144 of each adjacent wear-resistant strip 140 (i.e., along the angular distance). Figure 10 and Figure 11 coordinate axes + / - The distance in the direction increases as the distance increases.

[0051] Now for reference Figure 12 In some embodiments, the base plate 120 may not have wear-resistant strips extending axially from the upper axial surface 124 of the base plate 120. In these embodiments, the base plate 120 may have an opening 130, the size of which is based on the angular position of the opening 130 on the base plate 120 (i.e., along the angle of the opening 130). Figure 12 + / - of the middle coordinate axis The opening 130 may change in the direction of the angular orientation. In an embodiment, the opening 130 may have a repeating pattern in which the size of the opening 130 increases or decreases relative to the angular orientation.

[0052] Now for reference Figure 13In an embodiment, the opening 130 in the working area 136 of the base plate 120 can have a size that varies depending on the radial position of the opening 130 relative to the center 128 of the base plate 120. As previously described, the pressure causing axial flow through the base plate and the potential energy generated by the pressure increase with increasing radial distance from the central axis A of the rotor 105 (i.e., the center 128 of the base plate 120). To compensate for the increased pressure and the resulting potential energy with increasing radius, the opening 130 in the base plate 120 can be larger near the center 128 of the base plate and can decrease in size with increasing radial distance from the center 128 of the base plate 120. The size of the opening 130 at the outermost portion of the working area 136 of the base plate 120 can be smaller than the size of the opening 130 closer to the center 128 of the base plate 120. Increasing the size of the opening 130 near the center 128 of the base plate 120 and decreasing the size of the opening 130 at the outermost part of the working area 136 near the base plate 120 can make the volumetric flow rate through the opening 130 to the extraction chamber more consistent in the radial position, which can improve the efficiency of the base plate for grading pulp fibers and / or removing solid contaminants from pulp.

[0053] In an embodiment, the size of opening 130 may be at its maximum size at the location closest to the center opening of base plate 120, and the size of opening 130 may gradually decrease with increasing radial distance from the center 128 of base plate 120. The minimum opening size may be for an opening in working area 136 that is at its maximum radial distance from the center 128 of base plate 120 but still within working area 136. In an embodiment, base plate 120 may include a first opening 154 and a second opening 156, the first opening 154 being located at a first radial distance from the center 128 of base plate 120, and the second opening 156 being located at a second radial distance from the center 128 of base plate 120, wherein the first radial distance may be greater than the second radial distance, and the first opening 154 may have a first size smaller than the second size of the second opening 156. Referring now... Figure 14 In one embodiment, the base plate 120 may not have any wear-resistant strips on its upper axial surface 124, and the size of the opening 130 may be varied based on the radial position of the opening, for example, the size of the opening 130 may decrease as the radial distance from the center 128 of the base plate 120 increases.

[0054] Now for reference Figure 15 In this embodiment, the size of the opening 130 can be determined based on the radial distance of the opening 130 from the center 128 of the base plate 120 and the angular position of the opening 130 relative to the wear-resistant strip 140 (i.e., along the radial distance). Figure 11-13 + / - of the middle coordinate axis The size of the opening 130 varies with the radial distance from the center 128 of the base plate 120 and the angular distance from the high-pressure side 142 of the wear-resistant strip 140. In an embodiment, the largest opening 130 is closest to the center 128 of the base plate 120 and closest to the low-pressure side 144 of the wear-resistant strip 140, while the smallest opening 130 is at the maximum distance from the center 128 of the base plate 120 and closest to the high-pressure side 142 of the base plate 140.

[0055] Now for reference Figure 16 and Figure 17 In this embodiment, the cross-sectional shape of the opening 130 can be varied based on the position of the opening 130 within the working area 136 of the base plate 120. Now refer to... Figure 16 In an embodiment, the cross-sectional shape of the opening 130 can be based on the angular position of the opening 130 relative to the high-pressure side 142 of the wear-resistant strip 140 (i.e., along the angle of the opening 130 relative to the high-pressure side 142 of the wear-resistant strip 140). Figure 16 + / - of the middle coordinate axis The orientation of the opening 130 may change depending on the location of the opening. In an embodiment, the opening 130 in the base plate 120 may include a first opening and a second opening, wherein the first opening and the second opening are located at the same radial distance from the center 128 of the base plate 120. The first opening may have a first angular position relative to the reference wear strip 140, and the second opening may have a second angular position relative to the reference wear strip 140. The first opening may have a different shape than the second opening.

[0056] Now for reference Figure 17 In an embodiment, the cross-sectional shape of the opening 130 can be varied based on its radial distance from the center 128 of the base plate 120. In an embodiment, the base plate 120 may include a first opening and a second opening. The first opening is located at a first radial distance from the center 128 of the base plate 120, and the second opening is located at a second radial distance from the center 128 of the base plate 120. The first radial distance may be greater than the second radial distance, and the first opening may have a first shape different from the second shape of the second opening. In an embodiment, the shape of the opening 130 can vary based on both its radial and angular positions.

[0057] Now for reference Figure 18In an embodiment, the opening 130 may have a non-circular shape, and the orientation of the non-circular shape of the opening 130 may vary based on the position of the opening on the base plate 120. The orientation of the non-circular shape of the opening 130 may vary based on the radial distance of the opening 130 from the center 128 of the base plate 120, the angular position relative to one or more wear strips 140, or both in the radial and angular directions. Changing the orientation of the shape refers to rotating the shape about the centerline of the opening, where the centerline of the opening is a line passing through the geometric center of the shape of the opening 130 at the upper axial surface 124 of the base plate 120 and at the lower axial surface 126 of the base plate 120. For an opening 130 extending axially through the base plate 120, the centerline may be parallel to the rotor 105 (…). Figure 2 The central axis A of the opening 130 is an axial line that passes through the geometric center of the cross-sectional shape of the opening 130. In other words, the cross-sectional shape of the opening 130 can be rotated relative to each other based on the radial and / or angular position of the opening 130 on the base plate 120.

[0058] Now for reference Figure 19 In one embodiment, the base plate 120 may include a plurality of wear strip openings 146. The wear strip openings 146 may be axially extending openings in the base plate that pass through the base plate 120 and the wear strips 140. When the base plate 120 includes wear strip openings 146, each wear strip 140 may have a width greater than that of a wear strip 140 without wear strip openings 146.

[0059] refer to Figure 19 In one embodiment, the opening 130 may extend axially through the base plate 120, such that the centerline 180 is perpendicular to the upper axial surface 124 of the base plate 120 and parallel to the rotor 105. Figure 2 The central axis A of ) is now referenced. Figure 20 and Figure 21 In the embodiment, the opening 130 is relative to the axial direction (i.e., Figure 20 and Figure 21 The orientation of the + / -Z direction of the coordinate axis can be changed based on the radial and / or angular position of the opening 130 on the base plate 120.

[0060] Now for reference Figure 20 In an embodiment, the opening 130 may be relative to the axial direction (i.e., Figure 20The opening 130 is at an angle to the + / -Z direction of the coordinate axis. The opening 130 may have a centerline 180 that is not perpendicular to the upper axial surface 124 of the base plate 120, such that the centerline 180 of the opening 130 forms a non-zero angle α (alpha) with the axial line 182 perpendicular to the upper axial surface 124 of the base plate 120. In embodiments, the angle α may be less than 45 degrees, less than or equal to 40 degrees, less than or equal to 35 degrees, or even less than or equal to 30 degrees. In the embodiments, the angle can be from 0 degrees to 45 degrees, from 0 degrees to 40 degrees, from 0 degrees to 35 degrees, from 0 degrees to 30 degrees, from 5 degrees to 45 degrees, from 5 degrees to 40 degrees, from 5 degrees to 35 degrees, from 5 degrees to 30 degrees, from 10 degrees to 45 degrees, from 10 degrees to 40 degrees, from 10 degrees to 35 degrees, from 10 degrees to 30 degrees, from 15 degrees to 45 degrees, from 15 degrees to 40 degrees, from 15 degrees to 35 degrees, from 15 degrees to 30 degrees, from 20 degrees to 45 degrees, from 20 degrees to 40 degrees, from 20 degrees to 35 degrees, or from 20 degrees to 30 degrees.

[0061] In this embodiment, all openings 130 may have the same angle α. (See reference) Figure 20 and Figure 21 The angle α of the opening 130° can be tilted in the angular direction (i.e., along...). Figure 20 and Figure 21 + / - of the middle coordinate axis Direction). In other words, in the embodiment, the centerline 180 of the opening 130 can be at an angle ( The axial line 182 deviates from the axial line 182 perpendicular to the upper axial surface 124 of the base plate 120 in the direction of deviation. (Reference) Figure 20 In an embodiment, the opening 130 may be angled toward the low-pressure side 144 of the wear strip 140, such that the end of each opening 130 at the upper axial surface 124 of the base plate 120 is closer to the low-pressure side 144 of the wear strip 140 than the end of the opening at the lower axial surface 126 of the base plate 120 (e.g., along the...). Figure 20 The middle coordinate axis - (Direction at an angle). Reference Figure 21 In an embodiment, the opening 130 may be angled toward the high-pressure side 142 of the wear-resistant strip 140, such that the end of each opening 130 at the upper axial surface 124 of the base plate 120 is closer to the high-pressure side 142 of the wear-resistant strip 140 than the end of the opening at the lower axial surface 126 of the base plate 120 (e.g., along the...). Figure 21 The + of the middle coordinate axis (Direction at an angle).

[0062] Now for reference Figure 22 and Figure 23 In an embodiment, the opening 130 in the base plate 120 can be in the radial direction (i.e., Figure 22 and Figure 23The coordinate axes are angled (i.e., tilted) in the + / -r direction. In an embodiment, the centerline 180 of each opening 130 may deviate in the radial (r) direction from the axial line 182 perpendicular to the upper axial surface 124 of the base plate 120. Reference Figure 22 In an embodiment, the openings 130 may be angled radially outward, such that the end of each opening 130 at the upper axial surface 124 of the base plate 120 is closer to the outer circumference 129 of the base plate 120 than the end of the opening 130 at the lower axial surface 126 of the base plate 120 (e.g., along the...). Figure 22 (The +r direction of the mid-axis forms an angle). Reference Figure 23 In an embodiment, the openings 130 may be angled radially inward such that the end of each opening 130 at the upper axial surface 124 of the base plate 120 is closer to the central axis A of the base plate 120 than the end of the opening at the lower axial surface 126 of the base plate 120 (e.g., along the central axis A). Figure 23 The -r direction of the coordinate axis forms an angle.

[0063] exist Figure 22 and Figure 23 In the diagram, the opening 130 in the working area 136 is shown angled, and the external opening 139 in the non-working area 138 of the base plate is shown extending axially through the base plate 120 (i.e., angle α = zero). It should be understood that the external opening 139 in the non-working area 138 of the base plate 120 can also be in the angular direction (i.e., Figure 22 and Figure 23 + / - of the middle coordinate axis In the direction) or in the radial direction (i.e., Figure 22 and Figure 23 The coordinate axes (+ / -r directions) form an angle.

[0064] Now for reference Figure 24 The openings 130 can all have the same angle α, but the size of the openings 130 can be based on the angular position of the openings 130 relative to the wear strip 140 (i.e., along the angle α). Figure 24 coordinate axes + / - The orientation (position) changes. In an embodiment, the opening 130 may have an angle α inclined toward the low-pressure side 144 of the wear strip 140, and the size of the opening 130 may increase from a minimum size near the high-pressure side 142 of the wear strip 140 to the low-pressure side 144 of the adjacent wear strip 140. Although Figure 24 The opening 130 is shown to be angled or tilted toward the low-pressure side 144 of the wear-resistant strip 140, but it should be understood that the opening 130 may also be angled or tilted toward the high-pressure side 142 of the wear-resistant strip 140.

[0065] Now for reference Figure 25The openings 130 can all have the same angle α, but the size of the openings 130 can be based on the radial position of the openings 130 (i.e., along the radial direction). Figure 25 The position of the coordinate axis in the + / -r direction changes. In an embodiment, the opening 130 may have an angle α inclined towards the central axis A, and the size of the opening 130 may increase from a minimum size near the non-working area 138 of the base plate 120 to a maximum size near the central axis A of the base plate 120. Although Figure 25 The opening 130 is shown to be angled or tilted toward the central axis A of the base plate 120, but it should be understood that the opening 130 may also be angled or tilted toward the outer circumference 129 of the base plate 120.

[0066] In an embodiment, opening 130 may be configured such that a non-zero angle α (alpha) of the centerline 180 of opening 130 varies based on the radial and / or angular position of opening 130 on base plate 120. (See reference...) Figure 26 In one embodiment, the base plate 120 may have a substantially axial opening 130 at the low-pressure side 144 closest to the wear strip 140 and an angled opening 130 at the high-pressure side 142 closest to the adjacent wear strip 140. In another embodiment, the angle α (alpha) may vary from the low-pressure side 144 of one wear strip 140 to the high-pressure side 142 of an adjacent wear strip 140, for example, from approximately zero degrees at the low-pressure side 144 to a non-zero angle α (alpha) of less than 90 degrees, less than 60 degrees, less than 45 degrees, less than 30 degrees, or less than 20 degrees at the high-pressure side 142 of the adjacent wear strip 140. In the embodiment, the angle α of the opening 130 closest to the low-pressure side 144 of a wear-resistant strip 140 can be from zero to 30 degrees, from zero to 25 degrees, from zero to 20 degrees, from zero to 15 degrees, from zero to 10 degrees, from zero to 5 degrees, or any range or subrange thereof, and the angle α of the opening 130 closest to the high-pressure side 142 of the adjacent wear-resistant strip 140 can be from 20 degrees to 45 degrees, for example from 25 degrees to 45 degrees, from 30 degrees to 45 degrees, from 35 degrees to 45 degrees, from 40 degrees to 45 degrees, or any range or subrange thereof.

[0067] Now for reference Figure 27In one embodiment, the base plate 120 may have a substantially axial opening 130 at the high-pressure side 142 closest to the wear strip 140 and an angled opening 130 at the low-pressure side 144 closest to the adjacent wear strip 140. In another embodiment, the angle α (alpha) may increase from approximately zero degrees at the high-pressure side 142 to a non-zero angle α (alpha) of less than 90 degrees, less than 60 degrees, less than 45 degrees, less than 30 degrees, or less than 20 degrees at the low-pressure side 144 of the adjacent wear strip 140. In the embodiment, the angle α of the opening 130 closest to the high-pressure side 142 of a wear-resistant strip 140 can be from zero to 30 degrees, from zero to 25 degrees, from zero to 20 degrees, from zero to 15 degrees, from zero to 10 degrees, from zero to 5 degrees, or any range or subrange thereof, and the angle α of the opening 130 closest to the low-pressure side 144 of the adjacent wear-resistant strip 140 can be from 20 degrees to 45 degrees, for example from 25 degrees to 45 degrees, from 30 degrees to 45 degrees, from 35 degrees to 45 degrees, from 40 degrees to 45 degrees, or any range or subrange thereof.

[0068] Despite Figure 26 and Figure 27 The diagram shows the opening 130 angled toward the low-pressure side 144 of the wear-resistant strip 140, but in an embodiment, the opening 130 may be angled toward the high-pressure side 142 of the wear-resistant strip. In an embodiment, the opening 130 may be angled toward the high-pressure side 142 of the wear-resistant strip. direction,- The opening 130 may be angled toward the low-pressure side 144 near the wear-resistant strip 140, or it may be angled toward the high-pressure side 142 near the wear-resistant strip 140. In an embodiment, the opening 130 near the low-pressure side 144 may be angled toward the high-pressure side 142, and the opening 130 near the high-pressure side 142 may be angled toward the low-pressure side 144.

[0069] Now for reference Figure 28 In this embodiment, the size and angle α of the opening 130 can vary with the angular position between the wear-resistant strips 140 (i.e., along the angle α). Figure 28 coordinate axes + / - Changes occur due to a change in direction. For example... Figure 28 As shown, the opening 130 closest to the low-pressure side 144 of the wear-resistant strip 140 can have the largest size and the smallest angle α. As the angle direction along + The direction can be adjusted, the size of the opening 130 can be reduced, and the angle α can be increased. In the embodiment, both the size and the angle α can be adjusted according to the angular direction from the low-pressure side 144 of one wear strip 140 to the high-pressure side 142 of the adjacent wear strip 140 (i.e., + (Direction) increases. Although Figure 28The angle α of the opening 130 is shown as an angle toward the low-pressure side 144 of the wear-resistant strip 140, but it should be understood that the angle α of the opening 130 may be an angle toward the high-pressure side 142 of the wear-resistant strip 140.

[0070] Now for reference Figure 29 and Figure 30 In this embodiment, the angle α (alpha) of the opening 130 can vary based on the radial position of the opening 130 relative to the central axis A of the base plate 120. (See reference...) Figure 29 In an embodiment, the opening 130 closest to the central axis A (e.g., the opening closest to the central axis A) can have a small angle α. The angle α of the opening 130 can vary with the radial distance from the central axis A of the base plate 120 (i.e., Figure 29 The angle α increases with the radial distance from the central axis (in the +r direction). Therefore, the opening 130 near the non-working area 138 of the base plate 120 can have a larger angle α compared to the opening 130 closer to the central axis A. In the embodiment, the angle α of the opening 130 can gradually increase with the radial distance from the central axis A.

[0071] Now for reference Figure 30 In an embodiment, the opening 130 closest to the central axis A (e.g., the opening closest to the central axis A) can have a large angle α. The angle α of the opening 130 can vary with the radial distance from the central axis A of the base plate 120 (i.e., Figure 30 The angle α decreases as the radial distance from the central axis A increases. Therefore, the opening 130 in the non-working area 138 near the base plate 120 can have a smaller angle α compared to the opening 130 closer to the central axis A. In the embodiment, the angle α of the opening 130 can gradually decrease as the radial distance from the central axis A increases.

[0072] When the angle α of the opening 130 changes based on the radial distance from the central axis A, the opening 130 can be radially outward at an angle (e.g., Figure 29 (in the middle), radially inward at an angle (such as...) Figure 30 (Medium), or a combination of both. In an embodiment, the angle α can vary according to the radial distance of the opening 130 from the central axis A, but the opening 130 can be + / - Angles in direction or any other direction. Although in Figure 29 or Figure 30 Not shown in the figure, but in the embodiment, both the size of the opening 130 and the angle α can vary with the radial distance from the central axis A of the base plate 120.

[0073] Now for reference Figure 31In embodiments, the profile of the opening 130 at the upper axial surface 124, the lower axial surface 126, or both, can be varied based on the radial position, angular position, or both of the opening 130 on the base plate 120. For example... Figure 31 As shown, in an embodiment, each opening 130 may have a chamfer 190 at the upper axial surface 124, the lower axial surface 126, or both. In an embodiment, the chamfer 190 of the opening 130 may be varied based on the radial position, angular position, or both of the opening 130 on the base plate 120. Figure 31 As shown, in the embodiment, the chamfer 190 of the opening 130 may be small or non-existent near the low-pressure side 144 of a wear-resistant strip 140, and its size may increase as the opening 130 moves further away from the low-pressure side 144 and closer to the high-pressure side 142 of the adjacent wear-resistant strip 140. Figure 31 In the middle, the size of the chamfer 190 of the opening 130 extends from the low-pressure side 144 of a wear-resistant strip 140 to the high-pressure side 142 of the adjacent wear-resistant strip 140. Figure 31 coordinate axes + The direction increases.

[0074] Now for reference Figure 32 and Figure 33 In one embodiment, the opening 130 may be formed as a slot 192 in the base plate 120. In another embodiment, the size of the slot 192 may be varied based on the radial position, angular position, or both of the opening on the base plate 120. Referring now... Figure 32 In an embodiment, the size of slot 192 can be varied based on its radial distance from the center 128 of base plate 120. Slot 192 can have a length and a width. Changing the size of slot 192 can include changing the length, width, or both of slot 192. In an embodiment, slot 192 can have its largest size at its radial position closest to the center 128 of base plate 120, and can have a decreasing size as the radial distance from the center 128 of base plate 120 increases. As discussed above, the smaller size of slot 192 at a greater radial distance from the center 128 of base plate 120 can be accommodated by the increasing size of rotor 105 ( ) as the radial distance increases. Figure 2 The higher pressure and fluid velocity generated by the tip velocity.

[0075] Now for reference Figure 33In an embodiment, the size of the slot 192 can vary with the angular position of the opening 130. In an embodiment, the size of the slot 192 can vary based on the angular position of the opening 130 relative to the wear strip 140. For example, in an embodiment, the slot 192 can have a maximum size near the low-pressure side 144 of the wear strip 140 and a minimum size near the high-pressure side 142 of the wear strip 140. This can accommodate differences in fluid flow conditions and fluid pressure between the high-pressure side 142 and the low-pressure side 144, as discussed previously herein. In an embodiment, the size of the slot 192 can increase in the angular direction from a minimum size near the high-pressure side 142 of the wear strip 140 to a maximum size near the low-pressure side 144 of the wear strip 140.

[0076] Now for reference Figure 34 In embodiments, the orientation of slot 192 can be varied based on radial position, angular position, or both. For example, in an embodiment, slot 192 may have a radial orientation at the radial distance closest to the center 128 of base plate 120 (e.g., the slot length is approximately aligned with the radial direction), and a greater angular orientation at the radially outer portion closest to the working area 136 of base plate 120 (e.g., the slot length is approximately aligned with the angular direction). (Orientation) Aligned and perpendicular to the radial direction. In an embodiment, the slot 192 may have an angular orientation at a radial distance closest to the center 128 of the base plate 120, and a radial orientation in the radially outer portion of the working area 136 of the base plate 120. The orientation of the slot 192 may gradually change with increasing radial distance from the center 128 of the base plate 120. In an embodiment, the orientation of the slot 192 may be changed based on the angular position between the wear strips 140.

[0077] Refer again Figure 1 This disclosure further discloses a method for processing pulp using the base plate 120 disclosed herein. The method may include introducing pulp into a pulp processing unit 100, which includes a container 102 and a rotor assembly 104 disposed at the bottom of the container 102. The rotor assembly 104 may include a rotor 105 and the base plate 120 of this disclosure, the base plate 120 having an opening 130, wherein the size, shape, or both of the opening 130 in the base plate 120 may have different sizes, shapes, or orientations depending on the location of the opening on the base plate 120. The rotor assembly 104, rotor 105, and base plate 120 may have any of the features or characteristics previously discussed herein with respect to these features. The pulp processing unit 100 may also include an extraction chamber 112 disposed on the side of the base plate 120 opposite to the rotor 105. The extraction chamber 112 may be in fluid communication with a fiber outlet 114 for producing good pulp. The pulp processing unit 100 may also include a fiber outlet 116 for producing waste.

[0078] The method may include operating the pulp processing unit 100 by rotating the rotor 105 relative to the base plate 120. Rotation of the rotor 105 relative to the base plate 120 allows good pulp fiber to pass through openings 130 in the base plate 120 and enter the extraction chamber 114, and allows waste fiber and solid contaminants to be conveyed to the waste fiber outlet 116. The base plate 120 having openings 130 (these openings 130 having varying sizes, shapes, and / or orientations) can improve the throughflow, reflow, and / or solid contaminant removal performance of each individual opening 130, which can improve the overall performance and efficiency of the base plate 120.

[0079] A first aspect of this disclosure relates to a base plate for a pulp processing unit, wherein the base plate includes a plate having an upper axial surface, a lower axial surface, and a plurality of openings extending through the plate from the upper axial surface to the lower axial surface. Each of the plurality of openings has a shape, a size, and an angle. The shape is the cross-sectional shape of each of the plurality of openings in a plane perpendicular to the central axis of the base plate. The size is equal to the maximum cross-sectional dimension of each of the plurality of openings. The angle is the angle formed between the centerline of each of the plurality of openings and an axial line parallel to the central axis of the base plate. The shape, size, orientation of the shape, angle, or combination thereof of the plurality of openings varies depending on the position of each of the plurality of openings on the base plate.

[0080] The second aspect of this disclosure may include the first aspect, wherein the size of each of the plurality of openings may vary relative to the position of each of the plurality of openings on the plate.

[0081] A third aspect of this disclosure may include the second aspect, wherein the size of each of the plurality of openings may vary relative to the radial position of each of the plurality of openings from the center of the base plate.

[0082] The fourth aspect of this disclosure may include any one of the second or third aspects, wherein the size of each of the plurality of openings may decrease as the radial distance of each of the plurality of openings to the center of the base plate increases.

[0083] The fifth aspect of this disclosure may include any one of the second to fourth aspects, wherein the plurality of openings may include a first opening and a second opening, the first opening being disposed at a first radial distance from the center of the plate, the second opening being disposed at a second radial distance from the center of the plate, wherein the first radial distance may be greater than the second radial distance, and the first opening may have a first dimension smaller than the second dimension of the second opening.

[0084] The sixth aspect of this disclosure may include any one of the second to fifth aspects, wherein the plurality of openings may vary in angular position on the base plate relative to each of the plurality of openings.

[0085] The seventh aspect of this disclosure may include any one of the second to sixth aspects, and further includes a plurality of wear-resistant strips extending outward from the upper axial surface of the base plate, wherein the size of each of the plurality of openings may vary relative to the angular position of each of the plurality of openings relative to the wear-resistant strip.

[0086] The eighth aspect of this disclosure may include any one of the second to seventh aspects, wherein the plurality of openings may include a first opening and a second opening, wherein the first opening and the second opening may be located at the same radial distance from the center of the base plate, the first opening may have a first angular position relative to the reference wear strip, the second opening may have a second angular position relative to the reference wear strip that is different from the first angular position, and the first opening may have a size different from the size of the second opening.

[0087] The ninth aspect of this disclosure may include any one of the second to eighth aspects, wherein the size of each of the plurality of openings may vary relative to the proximity of each of the plurality of openings to the high-pressure side of one of the plurality of wear-resistant strips.

[0088] The tenth aspect of this disclosure may include the ninth aspect, wherein each of the plurality of wear-resistant strips may include a high-pressure side and a low-pressure side; and at each radial distance from the center of the base plate, the size of each of the plurality of openings may increase with the angular distance from the high-pressure side of each wear-resistant strip to the low-pressure side of each adjacent wear-resistant strip.

[0089] The eleventh aspect of this disclosure may include any one of the eighth or ninth aspects, wherein: each of the plurality of wear-resistant strips may include a high-pressure side and a low-pressure side; the base plate may include a first opening near the high-pressure side of one of the plurality of wear-resistant strips and a second opening farther from the high-pressure side than the first opening; and the first opening may have a size smaller than the second opening.

[0090] The twelfth aspect of this disclosure may include any one of the second to eleventh aspects, wherein the size of each of the plurality of openings may vary depending on the radial position of each of the plurality of openings relative to the center of the base plate and the angular position relative to the wear strip.

[0091] The thirteenth aspect of this disclosure may include any one of the first to twelfth aspects, and also includes a plurality of wear strip openings, wherein each of the plurality of wear strip openings extends axially through one of the plurality of wear strips and the base plate.

[0092] The fourteenth aspect of this disclosure may include any one of the first to thirteenth aspects, wherein the shape of each of the plurality of openings may vary depending on the radial position, angular position, or both of the plurality of openings on the base plate.

[0093] The fifteenth aspect of this disclosure may include any one of the first to fourteenth aspects, wherein the orientation of the shape of each of the plurality of openings may vary depending on the radial position, angular position, or both of the plurality of openings on the base plate.

[0094] The sixteenth aspect of this disclosure may include any one of the first to fifteenth aspects, wherein the angle of each of the plurality of openings may vary depending on the radial position, angular position, or both of the plurality of openings on the base plate.

[0095] The seventeenth aspect of this disclosure may include any one of the first to sixteenth aspects, wherein the angle of each of the plurality of openings may be from 0 degrees to 45 degrees.

[0096] The eighteenth aspect of this disclosure may include any one of the first to seventeenth aspects, and further includes a plurality of wear-resistant strips extending outward from the upper axial surface of the base plate, wherein the angle of each of the plurality of openings may vary relative to the angular position of each of the plurality of openings relative to the wear-resistant strip.

[0097] The nineteenth aspect of this disclosure may include any one of the first to eighteenth aspects, wherein each of the plurality of openings may have a profile at the interface between the opening and an upper axial surface, a lower axial surface, or both, wherein the shape of the profile at the interface may vary depending on the radial position, angular position, or both of each of the plurality of openings on the base plate.

[0098] The twentieth aspect of this disclosure may include the nineteenth aspect, wherein the profile at the interface may be chamfered, and the size, shape, or both of the chamfer may vary depending on the radial position, angular position, or both of each of the plurality of openings on the base plate.

[0099] The 21st aspect of this disclosure may include any one of the first to twentieth aspects, and may relate to a pulp processing unit for processing fibrous materials, wherein the pulp processing unit includes a base plate of any one of the first to twentieth aspects. The pulp processing unit may also include a container and a rotor, and the base plate may be arranged such that its upper axial surface faces the rotor.

[0100] Although various embodiments of a base plate for a pulp processing unit have been described herein, it should be understood that each of these embodiments and techniques is contemplated for use alone or in combination with one or more embodiments and techniques. It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Therefore, it is intended that the specification cover modifications and variations of the various embodiments described herein, provided that such modifications and variations fall within the scope of the appended claims and their equivalents.

Claims

1. A base plate for a pulp processing unit, the base plate comprising: A plate having an upper axial surface, a lower axial surface, and a plurality of openings extending through the plate from the upper axial surface to the lower axial surface, wherein: Each of the plurality of openings has a shape, size, and angle; The shape is the cross-sectional shape of each of the plurality of openings in a plane perpendicular to the central axis of the base plate; The size is equal to the maximum cross-sectional dimension of each of the plurality of openings; The angle is the angle formed between the centerline of each of the plurality of openings and an axial line parallel to the central axis of the base plate; and The shape, size, orientation, angle, or combination thereof of the plurality of openings vary depending on the position of each of the plurality of openings on the base plate.

2. The base plate according to claim 1, characterized in that, The size of each of the plurality of openings varies relative to the position of each of the plurality of openings on the plate.

3. The base plate according to claim 2, characterized in that, The size of each of the plurality of openings varies with respect to the radial position of each of the plurality of openings from the center of the base plate.

4. The base plate according to any one of claims 2 or 3, characterized in that, The size of each of the plurality of openings decreases as the radial distance from each of the plurality of openings to the center of the base plate increases.

5. The base plate according to any one of claims 2-4, characterized in that, The plurality of openings includes a first opening and a second opening, the first opening being located at a first radial distance from the center of the plate, and the second opening being located at a second radial distance from the center of the plate, wherein: The first radial distance is greater than the second radial distance; and The first opening has a first size, which is smaller than the second size of the second opening.

6. The base plate according to any one of claims 2-5, characterized in that, It also includes a plurality of wear-resistant strips extending outward from the upper axial surface of the base plate, wherein the size of each of the plurality of openings varies with respect to the angular position of each of the plurality of openings relative to the wear-resistant strip.

7. The base plate according to claim 6, characterized in that, The plurality of openings includes a first opening and a second opening, wherein: The first opening and the second opening are at the same radial distance from the center of the base plate; The first opening has a first angular position relative to the reference wear-resistant strip, and the second opening has a second angular position relative to the reference wear-resistant strip that is different from the first angular position; and The first opening has a different size than the second opening.

8. The base plate according to any one of claims 6 or 7, characterized in that, The size of each of the plurality of openings varies relative to the proximity of each of the plurality of openings to the high-pressure side of one of the plurality of wear-resistant strips.

9. The base plate according to any one of claims 6-8, characterized in that: Each of the plurality of wear-resistant strips includes a high-pressure side and a low-pressure side; and At each radial distance from the center of the base plate, the size of each of the plurality of openings increases with the angular distance from the high-pressure side of each wear strip to the low-pressure side of each adjacent wear strip.

10. The base plate according to any one of claims 6-9, characterized in that: Each of the plurality of wear-resistant strips includes a high-pressure side and a low-pressure side; The base plate includes a first opening near one of the plurality of wear-resistant strips on the high-pressure side and a second opening farther from the high-pressure side than the first opening; and The size of the first opening is smaller than the size of the second opening.

11. The base plate according to any one of claims 2-10, characterized in that, The size of each of the plurality of openings varies according to the radial position of each of the plurality of openings relative to the center of the base plate and the angular position relative to the wear-resistant strip.

12. The base plate according to any one of claims 1-11, characterized in that, It also includes a plurality of wear-resistant strip openings, wherein each of the plurality of wear-resistant strip openings extends axially through one of the plurality of wear-resistant strips and the base plate.

13. The base plate according to any one of claims 1-12, characterized in that, The shape of each of the plurality of openings varies depending on the radial position, angular position, or both of the plurality of openings on the base plate.

14. The base plate according to any one of claims 1-13, characterized in that, The orientation of the shape of each of the plurality of openings varies depending on the radial position, angular position, or both of the plurality of openings on the base plate.

15. The base plate according to any one of claims 1-14, characterized in that, The angle of each of the plurality of openings varies depending on the radial position, angular position, or both of the plurality of openings on the base plate.

16. The base plate according to claim 15, characterized in that, The angle of each of the plurality of openings is from 0 degrees to 45 degrees.

17. The base plate according to any one of claims 15 or 16, characterized in that, It also includes a plurality of wear-resistant strips extending outward from the upper axial surface of the base plate, wherein the angle of each of the plurality of openings varies with respect to the angular position of each of the plurality of openings relative to the wear-resistant strip.

18. The base plate according to any one of claims 1-17, characterized in that, Each of the plurality of openings has a profile at the interface between the opening and the upper axial surface, the lower axial surface, or both, wherein the shape of the profile at the interface varies depending on the radial position, angular position, or both of each of the plurality of openings on the base plate.

19. The base plate according to claim 18, characterized in that, The contour at the interface is chamfered, and the size, shape, or both of the chamfer varies depending on the radial position, the angular position, or both of each of the plurality of openings on the base plate.

20. A pulp processing unit for processing fibrous materials, the pulp processing unit comprising a base plate according to any one of claims 1-19, wherein: The pulp processing unit further includes a container and a rotor; and The base plate is arranged such that its upper axial surface faces the rotor.

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