Patent Application
20230175204
Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to being prior art by inclusion in this section.
Mechanical refiners for treating fibrous material typically include two refiner elements substantially opposite to one another. One of the refiner elements, the rotor, is arranged to move with respect to a stationary refiner element, the stator. Between the rotor and the stator, a refiner gap is created into which the fibrous material to be refined is fed. The refiner elements include the refining surfaces that carry out the actual refining. The refining surfaces may be one integral structure, or they may consist of a plurality of refining surface segments arranged adjacent to one another forming the refining surface.
In some cases, the fibrous material, also referred to as feedstock 145, is introduced into the mechanical refiner 100 by the ribbon feeder type mechanism 150. The feedstock 145 is fed into the area of the rotor plate 110 and the stator plate 120 in a substantially axial (e.g., horizontal direction). The axial feedstock inlet flow must then be redirected into a radial direction (e.g., a substantially perpendicular plane) to enter the refining gap 140 between the rotor plate 110 and the stator plate 120.
As the inlet feedstock flow enters the mechanical refiner, the feedstock 145 encounters a flinger plate 115 at a center portion of the rotating rotor plate 110. The rotating flinger plate 115 may use a small number of vanes (e.g., 4-6 vanes) to cause the horizontally flowing feedstock 145 to be redirected by centrifugal force through several individual openings into a plane substantially perpendicular to the horizontal feedstock inlet flow. The small number of vanes of the flinger plate 115 and the individual openings may can cause uneven distribution of the feedstock to the primary refining gap, resulting in uneven loads on the motor of the mechanical refiner.
Apparatuses and methods for providing a conical inlet transition zone for a mechanical refiner are provided.
According to various aspects there is provided conical inlet refiner elements for a mechanical refiner. In some aspects, the conical inlet refiner elements may include: a conical stator element disposed between a feedstock inlet to the mechanical refiner and primary refining plates of the mechanical refiner; a conical rotor element disposed between the feedstock inlet to the mechanical refiner and the primary refining plates, the conical rotor element configured to form an initial refining gap with the conical stator element. The conical stator element and the conical rotor element are configured to cause a radial change greater than zero but less than 90 degrees in a direction of an axial feedstock flow path through the initial refining gap at a feedstock inlet to a primary refining gap formed between the primary refining plates. The primary refining gap formed between the primary refining plates lies in a plane that is approximately perpendicular to the axial feedstock flow path.
According to various aspects there is provided a mechanical refiner. In some aspects, the mechanical refiner may include: conical inlet refiner elements including a conical stator element disposed between a feedstock inlet to the mechanical refiner and primary refining plates of the mechanical refiner; and a conical rotor element disposed between the feedstock inlet to the mechanical refiner and the primary refining plates, the conical rotor element configured to form an initial refining gap with the conical stator element. The conical stator element and the conical rotor element are configured to cause a radial change greater than zero but less than 90 degrees in a direction of an axial feedstock flow path through the initial refining gap at a feedstock inlet to a primary refining gap formed between the primary refining plates. The primary refining gap formed between the primary refining plates lies in a plane that is approximately perpendicular to the axial feedstock flow path.
According to various aspects there is provided a method for providing a conical inlet transition zone for a mechanical refiner. In some aspects, method may include: installing a conical stator element on a stator of the mechanical refiner between a feedstock inlet to the mechanical refiner and primary refining plates of the mechanical refiner; and installing a conical rotor element on a rotor of the mechanical refiner between the feedstock inlet to the mechanical refiner and the primary refining plates. The conical rotor element is configured to form an initial refining gap with the conical stator element. The conical stator element and the conical rotor element are configured to cause a radial change greater than zero but less than 90 degrees in a direction of an axial feedstock flow path through the initial refining gap of the pre-refining zone at a feedstock inlet to a primary refining gap formed between the primary refining plates. The primary refining gap formed between the primary refining plates lies in a plane that is approximately perpendicular to the axial feedstock flow path.
Aspects and features of the various embodiments will be more apparent by describing examples with reference to the accompanying drawings, in which:
While certain embodiments are described, these embodiments are presented by way of example only, and are not intended to limit the scope of protection. The apparatuses, methods, and systems described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions, and changes in the form of the example methods and systems described herein may be made without departing from the scope of protection.
Similar reference characters indicate corresponding parts throughout the several views unless otherwise stated. Although the drawings represent embodiments of various features and components according to the present disclosure, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate embodiments of the present disclosure, and such exemplifications are not to be construed as limiting the scope of the present disclosure.
Mechanical refiners for refining fibrous material may include two primary refiner elements: a rotating rotor plate and a stationary stator plate. Each of the rotor plate and the stator plate include refining surfaces between which a gap is formed into which the fibrous material, also referred to as feedstock, is fed to carry out the actual refining. The refining gap formed between the refining surfaces of the primary refiner elements (e.g., the rotor plate and the stator plate) may be referred to as a primary refining gap. The refining surface of each primary refiner element may be one integral structure or may consist of a plurality of refining surface segments arranged adjacent to one another forming the refining surface.
According to aspects of the present disclosure, a conical inlet refining zone, also referred to herein as a pre-refining zone or an initial refining zone, may be provided for a mechanical refiner. The initial refining zone can provide pre-refining of the feedstock before it enters the primary refining gap. Pre-refining by conical elements forming the initial refining zone can more evenly distribute the feedstock to the primary refining gap and even out the load on the motor of the mechanical refiner. The conical elements forming the initial refining zone can also provide a continuous (e.g., 360 degree) opening for better distribution of the feedstock by conveying the feedstock to the primary refining gap on a conical path.
Referring to
The conical rotor element 220 may include a conical rotor ring 222 and a set of rotor segments 225. The conical rotor ring 222 may be configured to mount the set of rotor segments 225 at a predetermined radial angle with respect to an axial feedstock flow path 145 into the mechanical refiner. Each rotor segment 225 may include a series of bars and grooves forming a refining area configured to provide the pre-refining action for the feedstock.
The conical stator element 230 may include a conical stator ring 232 and a set of stator segments 235. The conical stator ring 232 may be configured to mount the set of stator segments 235 at a predetermined radial angle with respect to an axial feedstock flow path 145 into the mechanical refiner. The predetermined radial angle of the conical stator ring 232 may be substantially the same as the predetermined radial angle of the conical rotor ring 222 or may be different than the predetermined radial angle of the conical rotor ring 222. Each stator segment 235 may include a series of bars and grooves forming a refining area configured to provide the pre-refining action for the feedstock.
A refining gap between the conical stator element 230 and the conical rotor element 220 in the conical pre-refining zone 210 may be determined based on the requirements of the main refining zone. For example, when a finer refined feedstock is required to be produced by the main refining zone, a narrower refining gap may be set for the conical pre-refining zone 210. Conversely, if only a coarser refined feedstock is required to be produced by the main refining zone, a wider refining gap may be set for the conical pre-refining zone 210.
The refining gap for the conical pre-refining zone 210 may be set by adjusting the position of the conical stator element 230 with respect to the primary stator refining plates. For example, shims may be used to adjust the position of the conical stator element 230. Other methods of adjusting the position of the conical stator element 230 may be used without departing from the scope of the present disclosure. Alternatively, the position of the conical rotor element 220 with respect to the conical stator element 230 may be adjusted. For example, shims may be used to adjust the position of the conical rotor element 220. Other methods of adjusting the position of the conical rotor element 220 may be used without departing from the scope of the present disclosure.
A conical rotor ring 350 may be coupled to the rotor 360, for example by fasteners or another method. A set of rotor segments 355 may be coupled to the conical rotor ring 350, for example by fasteners. The set of rotor segments 355 may be mounted on the conical rotor ring 350 at a predetermined angle forming a conical rotor element. The predetermined angle may be provided by the configuration of the conical rotor ring 350. The predetermined angle may be a radial angle greater than zero but less than 90 degrees with respect to a direction of axial feedstock flow path 145. In some implementations, the predetermined angle may be a radial angle in a range of 10 degrees to 20 degrees with respect to the direction of axial feedstock flow path 145.
In some implementations, a single conical rotor refining surface rather than a set of individual rotor segments may be mounted on the conical rotor ring to perform the pre-refining operation on the feedstock. In some implementations, a single conical rotor refining surface rather than a set of individual rotor segments may be mounted on the conical rotor ring to perform the pre-refining operation on the feedstock. In some implementations, the conical rotor ring and conical rotor refining surface may be formed as a single conical piece.
A conical stator ring 370 may be coupled to the stator 380, for example by fasteners or another method. A set of stator segments 375 may be coupled to the conical stator ring 370, for example by fasteners. The set of stator segments 375 may be mounted on the conical stator ring 370 at a predetermined angle forming a conical stator element. The predetermined angle may be provided by the configuration of the conical stator ring 370. The predetermined angle may be a radial angle greater than zero but less than 90 degrees with respect to a direction of an axial feedstock flow path 145. In some implementations, the predetermined angle may be a radial angle in a range of 10 degrees to 20 degrees with respect to the direction of axial feedstock flow path 145.
In some implementations, a single conical stator refining surface rather than a set of individual stator segments may be mounted on the conical stator ring to perform the pre-refining operation on the feedstock. In some implementations, the conical stator ring and conical stator refining surface may be formed as a single conical piece.
The set of rotor segments 355 and the set of stator segments 375 may form a conical refining surface of an initial refining zone 390. The initial refining zone 390 can provide pre-refining of the feedstock before it enters the primary refining gap 340. Pre-refining by the conically mounted set of rotor segments 355 and the conically mounted set of stator segments 375 forming the initial refining zone can more evenly distribute the feedstock 145 to the primary refining gap and result in more even loading of the motor of the mechanical refiner. A continuous (e.g., 360 degree) opening may be formed by the conical elements to provide better distribution of the feedstock 145 by conveying the feedstock from the conical refining surface of the pre-refining zone to the primary refining gap on a conical path.
As illustrated in
The rotor segments mounted on the conical rotor ring 520 and the stator segments 535 mounted on the conical stator ring 530 may form an initial refining gap 540 having the predetermined radial angle θ. The horizontal feedstock flow path 145 entering the initial refining gap 540 may be redirected by an amount equal to the predetermined radial angle θ in a radial direction towards the primary refining zone 550. The pre-refined feedstock exiting the initial refining gap 540 may be distributed in a continuous (e.g., substantially 360 degree) feed from the conical pre-refining zone into the primary refining zone 550.
At block 820, a conical rotor ring may be installed on the rotor. The conical rotor ring may be coupled to the rotor shaft of the mechanical refiner, for example, by mechanical fasteners such as bolts or by another method. The conical rotor ring is configured to provide the predetermined radial angle θ for mounting the set of rotor segments.
The predetermined angle θ may be a radial angle greater than zero but less than 90 degrees with respect to a direction of axial feedstock flow path in the axial direction of the rotor shaft of the mechanical refiner. In some implementations, the predetermined angle θ may be a radial angle in a range of 10 degrees to 20 degrees with respect to the direction of axial feedstock flow path. In some implementations, the predetermined angle θ may be a radial angle of approximately 15 degrees. Feedstock flowing in an axial (e.g., horizontal) direction may be redirected by an amount equal to the predetermined radial angle θ in a radial direction towards the primary refining gap.
At block 830, a set of rotor segments may be installed on the conical rotor ring. The set of rotor segments may be coupled to the conical rotor ring, for example by mechanical fasteners or by another method. The set of rotor segments may be mounted on the conical rotor ring at the predetermined angle thereby forming a conical rotor element. The predetermined angle may be provided by the configuration of the conical rotor ring. In some implementations, a single conical rotor refining surface rather than a set of individual rotor segments may be may be mounted on the conical rotor ring to perform the pre-refining operation on the feedstock. In some implementations, the conical rotor ring and conical rotor refining surface may be formed as a single conical piece.
A series of bars and grooves is formed on each rotor segment of the set of rotor segments or on the single conical rotor refining surface. The series of bars and grooves may be formed at an angle selected to ensure that the pre-refined feedstock exiting the conical pre-refining zone will be substantially uniformly distributed into the primary refining zone. In some implementations, the series of bars and grooves of each rotor segment or on the single conical rotor refining surface may be formed at an angle in a range of 45 degrees to 60 degrees with respect to the axial feedstock flow path. Other angles for the bars and grooves that enable pre-refining and distribution of the pre-refined feedstock may be used without departing from the scope of the present disclosure.
At block 840, a conical stator ring may be installed on the stator. The conical stator ring may be coupled to the stator of the mechanical refiner, for example, by mechanical fasteners such as bolts or by another method. The conical stator ring is configured to provide the predetermined radial angle θ for mounting the set of stator segments.
The predetermined angle θ may be a radial angle greater than zero but less than 90 degrees with respect to a direction of axial feedstock flow path in the axial direction of the rotor shaft of the mechanical refiner. In some implementations, the predetermined angle θ may be a radial angle in a range of 10 degrees to 20 degrees with respect to the direction of axial feedstock flow path. In some implementations, the predetermined angle θ may be a radial angle of approximately 15 degrees. Feedstock flowing in an axial (e.g., horizontal) direction may be redirected by an amount equal to the predetermined radial angle θ in a radial direction towards the primary refining gap.
At block 850, a set of stator segments may be installed on the conical stator ring. The set of stator segments may be coupled to the conical stator ring, for example by mechanical fasteners or by another method. The set of stator segments may be mounted on the conical stator ring at the predetermined angle thereby forming a conical stator element. The predetermined angle may be provided by the configuration of the conical stator ring. In some implementations, a single conical stator refining surface rather than a set of individual stator segments may be mounted on the conical stator ring to perform the pre-refining operation on the feedstock. In some implementations, the conical stator ring and conical stator refining surface may be formed as a single piece.
A series of bars and grooves is formed on each stator segment of the set of stator segments or on the single conical stator refining surface. The series of bars and grooves may be formed at an angle selected to ensure that the pre-refined feedstock exiting the conical pre-refining zone will be substantially uniformly distributed into the primary refining zone. In some implementations, the series of bars and grooves of each stator segment or on the single conical stator refining surface may be formed at an angle in a range of 45 degrees to 60 degrees with respect to the axial feedstock flow path. Other angles for the bars and grooves that enable pre-refining and distribution of the pre-refined feedstock may be used without departing from the scope of the present disclosure.
The specific operations illustrated in
According to aspects of the present disclosure, a conical inlet refining zone (e.g., a pre-refining zone or an initial refining zone) for a mechanical refiner is provided. The conical inlet refining zone can provide pre-refining of the feedstock before it enters the primary refining gap. Pre-refining the feedstock by the initial refining zone can more evenly distribute the feedstock in a continuous (e.g., 360 degree) conical path to the primary refining gap and even out the load on the motor of the mechanical refiner. The conical refining elements for the conical inlet refining zone may be installed during new buildup of a mechanical refiner or maybe retrofit to existing mechanical refiners. In addition, providing the conical inlet refining zone may enable the use of wider primary refining gap thereby extending the life of the primary refining plates.
The examples and embodiments described herein are for illustrative purposes only. Various modifications or changes in light thereof will be apparent to persons skilled in the art. These are to be included within the spirit and purview of this application, and the scope of the appended claims, which follow.
