阅读说明：本技术 精磨机 (Fine grinding machine ) 是由 R·穆诺兹 于 2020-10-09 设计创作，主要内容包括：一种用于精磨含木质纤维素的纤维材料的精磨机。精磨机包括至少两个大致相对定位的精磨元件,每个精磨元件包括至少一个精磨表面,精磨表面具有刀齿和刀槽。两个对置的精磨元件的精磨表面面向彼此并且在两者之间形成接收待精磨的纤维材料的精磨室。精磨机还包括至少两个进料通道,用于将至少一种待精磨的纤维材料组分送入精磨机；至少两个精磨区,在精磨区之间存在至少一个不同的精磨表面特征,每个精磨区用于精磨至少一种纤维材料组分的一种纤维材料组分；以及至少一个排出通道,用于从精磨机排出至少一种精磨材料流体。(A refiner for refining fibrous material containing lignocellulose. The refiner comprises at least two refining elements positioned substantially opposite each other, each refining element comprising at least one refining surface with blade teeth and blade grooves. The refining surfaces of two opposite refining elements face each other and form between them a refining chamber which receives the fibrous material to be refined. The refiner further comprises at least two feed channels for feeding at least one component of fibrous material to be refined into the refiner; at least two refining zones between which there is at least one different refining surface characteristic, each refining zone for refining one fibrous material component of the at least one fibrous material component; and at least one discharge channel for discharging at least one refining material fluid from the refiner.)

1. A refiner (1, 2, 3, 4) for refining lignocellulose-containing fibrous material, the refiner (1, 2, 3, 4) comprising:

at least two substantially oppositely positioned refining elements (6, 6a, 6b, 9), each of which comprises at least one refining surface (8, 8a, 8b, 11a, 11b) with a blade tooth (25, 27) and a blade groove (26, 28), the refining surfaces (8, 8a, 8b, 11a, 11b) of two substantially oppositely positioned refining elements (6, 6a, 6b, 9) facing each other and forming between them a refining chamber (15, 15a, 15b) receiving fibrous material to be refined;

at least two feed channels (19a, 19b) for feeding at least one fibrous material component (FM1, FM2) to be refined into the refiner (1, 2, 3, 4);

at least two refining zones (21a, 21b) having at least one different refining surface characteristic between the refining zones (21a, 21b), each refining zone (21a, 21b) being intended for refining one fibrous material component (FM1, FM2) of the at least one fibrous material component (FM1, FM 2); and

-discharge channels (23a, 23b) corresponding to the refining zones (21a, 21b) for discharging the fibrous material component (FM1, FM2) refined in the refining zones (21a, 21b) as a divided fluid from the refiner (1, 2, 3, 4).

2. Refiner according to claim 1, characterized in that the refiner (1, 2, 3, 4) comprises:

a first feed channel (19a) for feeding a first fibrous material component (FM1) into the refiner (1, 2, 3, 4);

-a second feed channel (19b) for feeding a second fibrous material component (FM2) into the refiner (1, 2, 3, 4); and

a first refining zone (21a) for refining the first fibrous material component (FM1), and a second refining zone (21b) for refining the second fibrous material component (FM 2).

3. The refiner of claim 2, wherein the refiner (1, 2, 3) comprises a fixed refiner element (6) and a rotatable refiner element (9), the rotatable refiner element (9) being inside the fixed refiner element (6) and substantially opposite the fixed refiner element (6) such that a refiner chamber (15) is formed between the opposite refining surfaces (8, 11) of the refiner elements (6, 9), and wherein the refiner (1, 2, 3), the refiner element (6, 9) and the refiner chamber (15) have an axial direction (a) and a first end (Ea) and a second end (Eb) opposite the first end (Ea) in the axial direction (a), and

in the axial direction (a) of the refining chamber (15), at a first end (Ea) of the refining chamber (15a) there is a first refining zone (21a) extending towards a second end (Eb) of the refining chamber (15) for refining a first fraction of fibrous material (FM1), and at a second end (Eb) of the refining chamber (15) there is a second refining zone (21b) extending towards the first end (Ea) of the refining chamber (15) for refining a second fraction of fibrous material (FM2), the second refining zone (21b) having at least one different refining surface characteristic relative to the first refining zone (21 a).

4. Refiner according to claim 3,

said first feed channel (19a) being arranged to feed said first fibrous material component (FM1) through a first end (Ea) of said refining chamber (15) into said first refining zone (21a),

the second feed channel (19b) being arranged to feed the second fibrous material component (FM2) through the second end (Eb) of the refining chamber (15) into the second refining zone (21b), and

the fixed refining element (6) comprises at least one opening (16a, 16b) in each refining zone (21a, 21b), which allows the fibrous material (FM1, FM2) refined in the respective refining zone (20a, 20b) to be discharged from the refining chamber (15) through the respective at least one opening (16a, 16 b).

5. Refiner according to claim 3,

the first feed channel (19a) being arranged to feed the first fibrous material component (FM1) through the first end (Ea) of the rotatable refining element (9) into the inner volume of the rotatable refining element (9),

the second feed channel (19b) is arranged to feed the second fibrous material component (FM2) through the second end (Eb) of the rotatable refining element (9) into the inner volume of the rotatable refining element (9), and

the rotatable refining element (9) comprises at least one opening (17a, 17b) in each refining zone (21a, 21b) allowing a fibrous material component (FM1, FM2) to be refined in the respective refining zone (21a, 21b) to be supplied through the respective at least one opening (17a, 17b) into the refining chamber (15) at the respective refining zone (21a, 21b), and

the fixed refining element (6) comprises at least one opening (16a, 16b) in each refining zone (21a, 21b), which allows the fraction of fibrous material (FM1, FM2) refined in the respective refining zone (21a, 21b) to be discharged from the refining chamber (15) at the respective refining zone (21a, 21b) through the respective at least one opening (16, 16 b).

6. A refiner as claimed in claim 2, characterized in that the refiner comprises: a first fixed refining element and a rotatable refining element (9) within and generally opposite the first fixed refining element such that a first refining chamber (15a) is formed between the opposing refining surfaces of the first fixed refining element and the rotatable refining element (9), the first refining chamber (15a) forming a first refining zone (21 a); and a second fixed refining element within the rotatable refining element (9) and substantially opposite the rotatable refining element (9) such that a second refining chamber (15b) is formed between the rotatable refining element (9) and the opposite refining surfaces of the second fixed refining element, the second refining chamber (15b) forming a second refining zone (21b), wherein at least one refining surface characteristic at the second refining zone (21b) is different from a corresponding at least one refining surface characteristic at the first refining zone (21a), wherein,

the refiner, the refining element and the refining chamber have an axial direction (A) and a first end (Ea) in the axial direction (A) and a second end (Eb) opposite to the first end (Eb), and

the first feed channel (19a) is arranged to feed the first fibrous material component (FM1) into the first refining chamber (15a) through at least one end (Ea, Eb) of the first refining chamber (15a), and

the second feed channel (19b) is arranged to feed the second fibrous material component (FM2) into the second refining chamber (15b) through at least one end (Ea, Eb) of the second refining chamber (15 b).

7. A refiner according to any one of the preceding claims, characterized in that the refiner is a conical refiner (1, 2) having a conical refining element (6, 9) with a first end (Ea) of smaller diameter and a second end (Eb) of larger diameter.

8. A refiner according to claim 1 or 2, characterized in that the refiner (4) comprises:

a first fixed disc refining element (6a) and a rotatable disc refining element (9) located immediately adjacent to the first fixed refining element (6a) and substantially opposite the first fixed refining element (6a) such that a first refining zone (21a) is formed between the opposing refining surfaces (8a, 11a) of the first fixed refining element (6a) and the rotatable refining element (9), the first refining zone (21a) forming a first refining chamber (15a),

a second disc-type fixed refining element (6b) immediately adjacent to the rotatable refining element (9) on the opposite side of the rotatable refining element (9) from the first fixed refining element (6a), the second fixed refining element (6b) being substantially opposite the rotatable refining element (9) such that a second refining zone (21b) is formed between the opposite refining surfaces (8b, 11b) of the rotatable refining element (9) and the second fixed refining element (6b), the second refining zone forming a second refining chamber (15b), wherein at least one refining surface characteristic at the second refining zone (21b) is different from a corresponding at least one refining surface characteristic at the first refining zone (21a), wherein,

the first feed channel (19a) is arranged to feed a first fibrous material component (FM1) into the first refining chamber (15a), and the second feed channel (19b) is arranged to feed a second fibrous material component (FM2) into the second refining chamber (15 b).

9. A refiner according to any of claims 2-8, characterized in that the refiner (1, 2, 3, 4) comprises:

a first discharge channel (23a) for discharging a first fibrous material component (FM1) refined in the first refining zone (21a) from the refiner (1, 2, 3, 4),

-a second discharge channel (23b) for discharging a second fibrous material fraction (FM2) refined in the second refining zone (21b) from the refiner (1, 2, 3, 4).

10. A refiner as claimed in any one of the preceding claims, characterized in that the refining surface feature is one of the following: tooth width, pocket width, tooth angle, tooth height, pocket depth, shape of the opening, and size of the opening.

11. A method for refining lignocellulose-containing fibrous material using a refiner (1, 2, 3, 4), which refiner (1, 2, 3, 4) comprises at least two substantially oppositely positioned refining elements (6, 6a, 6b, 9), the method comprising:

-feeding at least two flows of at least one fibrous material component (FM1, FM2) to be refined into the refiner (1, 2, 3, 4);

subjecting the at least two flows of the at least one fibrous material component (FM1, FM2) to different refining effects in the refiner (1, 2, 3, 4); and

the streams of fibrous material components subjected to different refining effects are discharged from the refiner (1, 2, 3, 4) as separate streams.

12. A method according to claim 11, wherein the refiner (1, 2, 3, 4) comprises a fixed refiner element (6) and a rotatable refiner element (9), the rotatable refiner element (9) being inside the fixed refiner element (6) and substantially opposite the fixed refiner element (6) so that a refiner chamber (15) is formed between the opposite refining surfaces (8, 11) of the refiner elements (6, 9), wherein the refiner (1, 2, 3), the refiner element (6, 9) and the refiner chamber (15) have an axial direction (a) and a first end (Ea) and a second end (Eb) opposite the first end (Ea) in the axial direction (a), and

in the axial direction (A) of the refining chamber (15), at a first end (Ea) of the refining chamber (15) there is a first refining zone (21a) extending towards a second end (Eb) of the refining chamber (15) for refining a first fibrous material fraction (FM1), and at a second end (Eb) of the refining chamber (15) there is a second refining zone (21b) extending towards the first end (Ea) of the refining chamber (15) for refining a second fibrous material fraction (FM2), the second refining zone (21b) having at least one refining surface characteristic different with respect to the first refining zone (21a), whereby

Feeding a first fibrous material component (FM1) to be refined into said first refining zone (21a),

feeding a second fibrous material component (FM2) to be refined into said second refining zone (21b),

the first fibrous material component (FM1) refined in the first refining zone (21a) is discharged from the refining chamber (15) at the first refining zone (21a) through at least one opening (16a) in the fixed refining element (6) arranged at the first refining zone (21a), and

the second fibrous material fraction (FM2) refined in the second refining zone (21b) is discharged from the refining chamber (15) at the second refining zone (21b) through at least one opening (16b) in the fixed refining element (6) arranged at the second refining zone (21 b).

13. The method of claim 12, wherein,

feeding the first fibrous material component (FM1) to be refined into the inner volume of the rotatable refining element (9) through the first end (Ea) of the rotatable refining element (9) and into the refining chamber (15) through at least one opening (17a) in the rotatable refining element (6) arranged at the first refining zone (21a),

-feeding the second fibrous material component (FM2) to be refined into the inner volume of the rotatable refining element (9) through the second end (Eb) of the rotatable refining element (9), and into the refining chamber (15) through at least one opening (17b) in the rotatable refining element (9) arranged at the second refining zone (21 b).

14. The method according to claim 12 or 13, wherein the quality of the second fiber material component (FM2) is different from the quality of the first fiber material component (FM 1).

Technical Field

The present invention relates to a refiner and a method for refining lignocellulose-containing fibrous material.

Background

During the manufacture of paper or board, one or more lignocellulose-containing wood-based fiber material components of different qualities may be mixed to produce a paper or board web. Due to the need to obtain a combination of qualities in the final product, such as a specific tensile strength with a specific grammage, it is necessary to mix fiber material components of different qualities. The fibre material components of different quality may comprise, for example, virgin hardwood and softwood based fibre pulp and different recycled fibre materials, such as long and short fibre pulp made from OCC (old corrugated containers).

Typically, the mixed pulp is formed by mixing at least two sets of differing quality fibrous material components from separate tanks, each particular tank being adapted to retain a particular quality of a single fibrous material component. However, the single fiber material may also comprise different qualities, such as OCC comprising both a long fiber component and a short fiber component. When considering refining of the fibrous material before feeding the refined fibrous material to the storage tank, each group of different fibrous material components is refined using a specially designed refiner having refining surface characteristics optimized for that particular fibrous material component. This means that each group of refined fibrous material components has a higher quality, but the number of refiners increases as the number of different fibrous material components to be mixed increases.

The number of refiners may be reduced by first mixing at least two sets of fibrous material components of different quality with each other or with fibrous material having a larger distribution of fiber lengths, such as OCC, and then refining the fibrous material slurry with a single refiner. In this case, however, the refining surface characteristics of the refiner are a compromise based on the refining requirements of the fibrous material component forming the pulp. Thus, the quality of the refined mixed pulp is not necessarily as high as the quality of the above-mentioned pulp formed by mixing at least two separately refined fibrous material components.

Disclosure of Invention

It is an object of the invention to provide a refiner and a method for refining lignocellulose-containing fibrous material.

The idea of the invention is to simultaneously refine at least two flows of at least one fibrous material component with a single refiner in different refining zones in a single refiner, the refining surface characteristics of the different refining zones being specifically designed in view of the fibrous material component to be refined in the refining zone and in view of the intended refining effect to which the fibrous material component is subjected in the refining zone. Thus, at least two flows of fibrous material may be fed to the refiner, which may be of the same fibrous material component or of different fibrous material components of different quality.

An advantage of the invention is that a single refiner can simultaneously refine at least one fibrous material component such that the at least one fibrous material component is subjected to different refining effects, whereby the fibrous material components subjected to different refining effects can be directed, for example, to different layers in the paper or board web to be manufactured or to different processes. Such refiners are particularly suitable for applications where the amount or volume of different fibrous material components required for the production of paper or board is moderate.

According to the present application, a refiner for refining lignocellulose-containing fibrous material, the refiner comprising: at least two substantially oppositely positioned refining elements, each of which comprises at least one refining surface having blade teeth and blade grooves, the refining surfaces of the two substantially oppositely positioned refining elements facing each other and forming a refining chamber therebetween for receiving fibrous material to be refined; at least two feed channels for feeding at least one fibrous material component to be refined into the refiner; at least two refining zones having at least one different refining surface characteristic therebetween, each refining zone for refining one of the at least one fibrous material components; and a discharge channel, corresponding to the refining zone, for discharging the fibrous material component refined in the refining zone as a separate fluid from the refiner.

In an embodiment, further comprising a first feed channel for feeding a first fibrous material component into the refiner; a second feed channel for feeding a second fibrous material component into the refiner; and a first refining zone for refining the first fibrous material component and a second refining zone for refining the second fibrous material component.

In one embodiment, the refiner comprises a stationary refining element and a rotatable refining element, the rotatable refining element being within and generally opposite the fixed refining element such that a refining chamber is formed between the opposing refining surfaces of the refining element, and wherein the refiner, the refining element and the refining chamber have an axial direction and a first end in the axial direction and a second end opposite the first end, and in the axial direction of the refining chamber, at a first end of the refining chamber, a first refining zone extending towards a second end of the refining chamber for refining a first fibrous material component, and a second refining zone at the second end of the refining chamber extending towards the first end of the refining chamber, for refining a second fibrous material component, said second refining zone having at least one different refining surface characteristic relative to said first refining zone.

In one embodiment, the first feed channel is arranged to feed the first fibrous material component into the first refining zone through a first end of the refining chamber, the second feed channel is arranged to feed the second fibrous material component into the second refining zone through a second end of the refining chamber, and the stationary refining element comprises at least one opening in each refining zone allowing fibrous material refined in the respective refining zone to exit the refining chamber through the respective at least one opening.

In one embodiment, the first feed channel is arranged to feed the first fibrous material component into the inner volume of the rotatable refiner element through the first end of the rotatable refiner element, the second feed channel being arranged to feed the second fibrous material component through the second end of the rotatable refining element into the inner volume of the rotatable refining element, and the rotatable refining element comprising at least one opening in each refining zone, which allows a fibrous material component to be refined in the corresponding refining zone to be supplied through a corresponding at least one opening into the refining chamber at the corresponding refining zone, and the stationary refining element comprises at least one opening in each refining zone, which allows the refined fibrous material component in the respective refining zone to be discharged from the refining chamber at the respective refining zone through the respective at least one opening.

In one embodiment, the refiner comprises: a first fixed refiner element and a rotatable refiner element within and generally opposite the first fixed refiner element such that a first refining chamber is formed between the opposed refining surfaces of the first fixed refiner element and the rotatable refiner element, the first refining chamber forming a first refining zone; and a second fixed refining element within and generally opposite the rotatable refining element such that a second refining chamber is formed between the opposing refining surfaces of the rotatable refining element and the second fixed refining element, the second refining chamber forming a second refining zone, wherein at least one refining surface feature at the second refining zone is different from a corresponding at least one refining surface feature at the first refining zone, wherein the refiner, the refining element, and the refining chamber have an axial direction and a first end in the axial direction and a second end opposite the first end, and

the first feed channel is arranged to feed the first fibrous material component into the first refining chamber through at least one end of the first refining chamber, and the second feed channel is arranged to feed the second fibrous material component into the second refining chamber through at least one end of the second refining chamber.

In one embodiment the refiner is a conical refiner having a conical refining element with a first end having a smaller diameter and a second end having a larger diameter.

In one embodiment, the refiner comprises: a first fixed disc refiner element and a rotatable disc refiner element proximate to and generally opposite the first fixed refiner element such that a first refining zone is formed between the opposed refining surfaces of the first fixed refiner element and the rotatable refiner element, the first refining zone forming a first refining chamber, a second disc fixed refiner element proximate to the rotatable refiner element on a side of the rotatable refiner element opposite the first fixed refiner element, the second fixed refiner element generally opposite the rotatable refiner element such that a second refining zone is formed between the opposed refining surfaces of the rotatable refiner element and the second fixed refiner element, the second refining zone forming a second refining chamber, wherein at least one refining surface feature at the second refining zone corresponds to a corresponding refining surface feature at the first refining zone At least one refining surface is characterized differently, wherein the first feed channel is arranged to feed a first fibrous material component into the first refining chamber and the second feed channel is arranged to feed a second fibrous material component into the second refining chamber.

In one embodiment, the refiner comprises: a first discharge channel for discharging a first fibrous material component refined in the first refining zone from the refiner and a second discharge channel for discharging a second fibrous material component refined in the second refining zone from the refiner.

In one embodiment, the refining surface feature is one of: tooth width, pocket width, tooth angle, tooth height, pocket depth, shape of the opening, and size of the opening.

According to the present application, a method for refining lignocellulose-containing fibrous material using a refiner comprising at least two substantially oppositely positioned refining elements, the method comprising: feeding at least two flows of at least one fibrous material component to be refined into the refiner; subjecting the at least two flows of the at least one fibrous material component to different refining effects in the refiner; and discharging the flow of fibrous material components subjected to different refining effects from the refiner as separate flows.

In one embodiment, wherein the refiner comprises a fixed refining element and a rotatable refining element inside and substantially opposite the fixed refining element such that a refining chamber is formed between the opposed refining surfaces of the refining element, wherein the refiner, the refining element and the refining chamber have an axial direction and a first end in the axial direction and a second end opposite the first end, and in the axial direction of the refining chamber at the first end of the refining chamber a first refining zone extending towards the second end of the refining chamber for refining a first fibrous material component and at the second end of the refining chamber a second refining zone extending towards the first end of the refining chamber for refining a second fibrous material component, the second refining zone having at least one refining surface characteristic different with respect to the first refining zone, whereby a first fibrous material component to be refined is fed into the first refining zone, a second fibrous material component to be refined is fed into the second refining zone, the first fibrous material component refined in the first refining zone is discharged from the refining chamber at the first refining zone through at least one opening in the fixed refining element arranged at the first refining zone, and the second fibrous material component refined in the second refining zone is discharged from the refining chamber at the second refining zone through at least one opening in the fixed refining element arranged at the second refining zone.

In one embodiment, the first fibrous material component to be refined is fed into the inner volume of the rotatable refining element through a first end of the rotatable refining element and into the refining chamber through at least one opening in the rotatable refining element arranged at the first refining zone, and the second fibrous material component to be refined is fed into the inner volume of the rotatable refining element through a second end of the rotatable refining element and into the refining chamber through at least one opening in the rotatable refining element arranged at the second refining zone.

In one embodiment, wherein the quality of the second fibrous material component is different from the quality of the first fibrous material component.

Drawings

The invention will be described in more detail hereinafter by means of preferred embodiments with reference to the accompanying drawings, in which,

figure 1 shows schematically a side view of a cone refiner partly in section;

figure 2 schematically shows a top view of a blade element suitable for use in the cone refiner of figure 1;

figure 3 shows schematically a side view, partly in section, of another cone refiner;

figure 4 shows schematically a side view of a cylindrical refiner with a partly sectional view; and

figure 5 shows schematically a side view, partly in section, of a disc refiner.

For the sake of clarity, the figures show some embodiments of the invention in a simplified manner. In the drawings, like numbering represents like elements.

Detailed Description

Figure 1 shows a very schematic side view, partly in cross-section, of a cone refiner 1 for refining lignocellulose-containing wood-based fibre material. The refiner 1 has a first end Ea with a smaller diameter and a second end Eb with a larger diameter.

The refiner 1 comprises a fixed refining element 6, i.e. a stator 6, the stator 6 having a first end facing the first end Ea of the refiner 1 and a second end facing the second end Eb of the refiner 1, whereby for the sake of clarity the reference Ea is also used to denote the first end of the stator 6 and the reference Eb is also used to denote the second end of the stator 6. The stator 6 is supported on the frame structure 5 of the refiner 1.

The stator 6 comprises a plurality of stator blade elements 7, the stator blade elements 7 having refining surfaces 8, the refining surfaces 8 of each stator blade element 7 contributing to provide a complete refining surface of the stator 6. The stator blade element 7 has a first end facing the first end Ea of the refiner 1 and a second end facing the second end Eb of the refiner 1, so for the sake of clarity the reference Ea is also used to denote the first end of the stator blade element 7 and the reference Eb is also used to denote the second end of the stator blade element 7.

According to an embodiment of the stator 6, it may comprise only one blade element 7 in the shape of a cone and the blade element 7 extends over the entire circumference of the stator 6, so that the refining surface 8 of this single blade element provides a complete and uniform refining surface of the stator 6. According to another embodiment of the stator 6, it may comprise at least two segmented blade elements, i.e. blade segments arranged adjacent to each other, whereby the refining surfaces 8 of the initially separate segmented blade elements together provide a complete and uniform refining surface of the stator 6. Thus, when referring to the stator 6 of the refiner 1, the term "blade element" may refer to a single blade element providing the complete refining surface of the stator 6, or a blade segment providing only a part of the complete refining surface of the stator 6. For the sake of clarity, the refining surface 8 of the single blade element 7 of the stator 6 and the complete refining surface 8 of the stator 6 may be denoted below with the same reference numeral 8. The refining surface 8 in the stator 6 is normally provided with blade teeth and blade grooves between them, after which some embodiments of blade teeth and blade grooves are shown in figure 2.

The refiner 1 further comprises a rotatable refining element 9, i.e. a rotor 9, the rotor 9 having a first end facing the first end Ea of the refiner 1 and a second end facing the second end Eb of the refiner 1, whereby for the sake of clarity the reference Ea is also used to indicate the first end of the rotor 9 and the reference Eb is also used to indicate the second end of the rotor 9.

The rotor 9 comprises a plurality of rotor blade elements 10, the rotor blade elements 10 having refining surfaces 11, the refining surface 11 of each rotor blade element 10 contributing to provide a complete refining surface 11 of the rotor 9. The rotor blade element 10 has a first end facing the first end Ea of the refiner 1 and a second end facing the second end Eb of the refiner 1, so for the sake of clarity the reference Ea is also used to denote the first end of the rotor blade element 10 and the reference Eb is also used to denote the second end of the rotor blade element 10.

According to one embodiment of the rotor 9, it may comprise only one conical blade element 10 extending over the entire circumference of the rotor 9, so that the single blade element provides the complete and uniform refining surface 11 of the rotor 9. According to another embodiment of the rotor 9, it may comprise at least two segmented blade elements, i.e. blade segments arranged adjacent to each other, whereby the refining surfaces 11 of the initially separate segmented blade elements together provide a complete and uniform refining surface of the rotor 9. Thus, when referring to the rotor 9 of the refiner 1, the term "blade element" may also refer to a single blade element providing the complete refining surface of the rotor 9, or a blade segment providing only a part of the complete refining surface of the rotor 9. For the sake of clarity, the same reference numeral 11 may be used below to designate the refining surface 11 for a single blade element 9 of the rotor 9 as well as the complete refining surface 11 of the rotor 9. The refining surface 11 in the rotor 9 is normally also provided with blade teeth and blade grooves between them, as shown later in figure 2.

The rotor 9 comprises a hub 12, at least one rotor blade element 10 being supported against the hub 12. In fig. 1 and in the following fig. 3 and 4, the hub 12 is highly simplified. The hub 12 of the rotor 9 is connected to a shaft 13. The shaft 13 is connected to a highly schematically depicted motor 14, which motor 14 is arranged to rotate the shaft 13 and, via the shaft 13, the rotor 9, for example, in the direction of rotation indicated by arrow RD.

For the sake of clarity, the refiner 1 may also comprise loading means, not shown in fig. 1, which may be connected to the shaft 13 for moving the rotor 9 back and forth, as schematically indicated by the arrow AD, for adjusting the distance between the stator 6 and the rotor 9, i.e. the size of the refining chamber 15 or blade gap 15 formed between the stator 6 and the rotor 9 or in the blade elements 7, 10. The refining chamber 15 thus forms a volume in which the fibrous material is refined. The dimensions of the refining chamber 15 in relation to the other parts of the refiner are exaggerated throughout the figures. The refining chamber 15 has a first end facing the first end Ea of the refiner 1 and a second end facing the second end Eb of the refiner 1, so for the sake of clarity the reference Ea is also used to denote the first end of the refining chamber 15 and the reference Eb is also used to denote the second end of the refining chamber 15.

The stator blade element 7 further comprises openings 16a, 16b through the stator blade element 7 and the rotor blade element 10 comprises openings 17a, 17b through the rotor blade element 10, whereby the openings 16a, 16b, 17a, 17b extend through the entire thickness of the stator blade element 7 and the rotor blade element 10. In the axial direction of the refiner 1 (and thus in the axial direction of both the stator blade element 7 and the rotor blade element 10, which axial direction is schematically indicated by arrow a in fig. 1), the openings 16a, 16b in the stator blade element 7 are in substantially the same axial position as the openings 17a, 17b in the rotor blade element 10 when the blade elements 7, 10 are facing each other. Alternatively, the axial position of the openings 16a, 16b in the stator blade element 7 and the axial position of the openings 17a, 17b in the rotor blade element 10 may be at least partially different.

Referring back to the embodiment of fig. 1, the refiner 1 comprises a first feed aggregate portion (feed aggregate)18a at the first end Ea of the refiner 1 and a first feed channel 19a connected to the first feed aggregate portion 18a, through which first feed aggregate portion 18a and first feed channel 19a first fibrous material component, schematically indicated by arrow FM1, is fed into a first feed chamber 20a provided by the inner volume of the rotor 9 on the side of the first end Ea of the rotor 9. The first inlet chamber 19a extends from the first end Ea of the rotor 9 towards the second end Eb of the rotor 9, but does not reach the second end Eb of the rotor 9.

The refiner 1 further comprises a second feed aggregate portion 18b at the first end Ea of the refiner 1 and a second feed channel 19b connected to the second feed aggregate portion 18b, through which second feed aggregate portion 18b and second feed channel 19b a second fibrous material component, schematically indicated by arrow FM2, is fed into a second feed chamber 20b, which second feed chamber 20b is provided by the inner volume of the rotor 9 on the side of the second end Eb of the rotor 9. The second inlet chamber 19b extends from the second end Eb of the rotor 9 towards the first end Ea of the rotor 9, but does not reach the first end Ea of the rotor 9.

Furthermore, in the embodiment of fig. 1, the refining surfaces 8, 11 in the stator 6 and the rotor 9 are designed or constructed in the axial direction a of the refiner 1 such that there are two different refining zones in the refining chamber 15, of which there is at least one different refining surface characteristic in the axial direction a of the refiner 1, namely a first refining zone 21a on the side of the first end Ea of the refiner 1 and indicated by the arrow 21a and a second refining zone 21b on the side of the second end Eb of the refiner 1 and indicated by the arrow 21 b. In the axial direction a of the refiner 1 the first refining zone 21a is substantially in a position corresponding to the first inlet chamber 20a of the refiner 1 and the second refining zone 21b is substantially in a position corresponding to the second inlet chamber 20b of the refiner 1. As briefly mentioned above, at least one refining surface characteristic at the first refining zone 21a is chosen such that it differs from the corresponding refining surface characteristic at the second refining zone 21 b. This normally means that the refining surface characteristics of the stator and rotor blade elements 7, 10 at the first refining zone 21a are designed in view of the refining effect of the first fibrous material component FM1 intended to be refined in the first refining zone 21a, and the refining surface characteristics of the stator and rotor blade elements 7, 10 at the second refining zone 21b are designed in view of the refining effect of the second fibrous material component FM2 intended to be refined in the second refining zone 21 b.

The refiner 1 of figure 1 operates as follows.

The first fibrous material component FM1 flows from the first inlet chamber 20a through the first openings 17a in the first refining zone 21a into the refining chamber 15, whereby the first fibrous material component FM1 is refined in the refining chamber 15 substantially in the first refining zone 21 a. Thus, in the first refining zone 21a, the first opening 17a connects the first inlet chamber 20a with the refining chamber 15. In the first refining zone 21a the first fibrous material component FM1 is subjected to a refining effect in the refining chamber 15 provided by the corresponding refining surface areas of the stator and rotor blade elements 7, 10. In the first refining zone 21a, the first fibrous material component FM1 refined in the refining chamber 15 is discharged from the refining chamber 15 through the first opening 16a to the discharge chamber 22 at the back of the stator blade element 7. Thus, in the first refining zone 21a, the first opening 16a connects the refining chamber 15 with the discharge chamber 22. In the first refining zone 21a, the first fibrous material component FM1 flows into the refining chamber 15 and the refined first fibrous material component FM1 flows out of the refining chamber 15, as schematically indicated by arrow FM 1.

The second fibrous material component FM2 flows from the second inlet chamber 20b through the second openings 17b in the second refining zone 21b into the refining chamber 15, whereby the second fibrous material component FM2 is refined in the refining chamber 15 substantially in the second refining zone 21 b. Thus, in the second refining zone 21b, the second opening 17b connects the second inlet chamber 20a with the refining chamber 15. In the second refining zone 21b the second fibrous material component FM2 is subjected to a refining effect in the refining chamber 15 provided by the corresponding refining surface areas of the stator and rotor blade elements 7, 10. In the second refining zone 21b, the second fibrous material component FM2 refined in the refining chamber 15 is discharged from the refining chamber 15 to the discharge chamber 22 through the second opening 16 b. Thus, in the second refining zone 21b, the second opening 16b connects the refining chamber 15 with the discharge chamber 22. In the second refining zone 21b, the second fibrous material component FM2 flows into the refining chamber 15 and the refined second fibrous material component FM2 flows out of the refining chamber 15, as schematically indicated by arrow FM 2.

In the discharge chamber 22, the refined first fibrous material component FM1 and the refined second fibrous material component FM2 are combined, whereby they are at least partially mixed with each other. As schematically indicated by the arrows denoted by reference numeral FM1+ FM2, the combined flow of refined first fibrous material component FM1 and refined second fibrous material component FM2 is discharged from the refiner 1 through a discharge channel 23 connected to a discharge chamber 22 and further through a discharge and collection portion 24 connected to the discharge channel 23. The combined flow of refined first fibrous material component FM1 and refined second fibrous material component FM2 is thus supplied as one flow to the subsequent treatment.

Thus, in the refiner 1, there are two refining zones 21a, 21b, so that the first refining zone 21a is designed specifically for refining the first fibrous material component FM1 and the second refining zone 21b is designed specifically for refining the second fibrous material component FM 2. Thus, the characteristics of the specific refining zones 21a, 21b are provided by the specific design of the refining surfaces 8, 11 of the stator and rotor blade segments 7, 10, which contributes to providing the refining zones 21a, 21 b. This has the advantage that a single refiner can be used to simultaneously refine two separate flows of fibrous material components having at least one different quality characteristic, thereby optimizing a specific portion of the refining surfaces 8, 11 of the stator and rotor blade segments 7, 10 for refining a specific fibrous material component. In other words, in case at least one refining surface feature of the first refining zone 21a differs from the corresponding refining surface feature of the second refining zone 21b, a single refiner may be provided for refining both sets of fibrous material fluid simultaneously.

According to one embodiment, the first fibre material component FM1 and the second fibre material component FM2 are the same fibre material, i.e. have the same quality. In this case, different portions of the same fibrous material may be subjected to different refining effects at different refining zones 21a, 21 b.

According to another embodiment, the second fibre material component FM2 and the first fibre material component FM1 are of different quality. When it is defined that the qualities of the second fiber material component FM2 and the first fiber material component FM1 are different, it means that at least one of the raw material, the particle size, the fiber length, the freeness, the residual lignin content and some other characteristics of the second fiber material component FM2 are different from the corresponding characteristics of the first fiber material component FM 1. The hub 12 in the rotor 9 is configured such that the first fibre material component FM1 in the first inlet chamber 20a and the second fibre material component FM2 in the second inlet chamber 20b do not mix with each other in the rotor 9.

According to another embodiment, the second fibrous material component FM2 may be the first fibrous material component FM1 that has been refined in the first refining zone 21a and discharged from the first refining zone 21 a. According to this embodiment, the refiner is capable of providing a secondary refining of the first fibrous material component FM 1.

Figure 2 schematically shows a top view of a blade element suitable for use in the stator 6 of the refiner 1 of figure 1. Figure 2 shows a single segmented blade element 7 for providing a part of the complete refining surface 8 of the stator 6. Figure 2 is only intended to illustrate possible different refining surface characteristics between the first and second refining zones 21a, 21 b. For clarity, only the segmented blade elements 7 for the stator 6 are disclosed in fig. 2, but the same design principles apply to the corresponding blade elements 10 in the rotor 9 to provide corresponding parts for the stator blade elements 7.

The blade element 7 of figure 2 comprises a first end Ea facing the first end Ea of the stator 6 and a second end Eb facing the second end Eb of the stator 6, and a refining surface 8. The blade element 7 further comprises two different refining surface areas, namely a first refining surface area 8a on the side of the first end Ea and a second refining surface area 8b on the side of the second end Eb. The first refining surface area 8a is intended to provide the refining surface 8 of the stator 6 in the first refining zone 21a of the refiner 1 and the second refining surface area 8b is intended to provide the refining surface 8 of the stator 6 in the second refining zone 21b of the refiner 1. A virtual dividing line between the first refining surface zone 8a and the second refining surface zone 8b is shown in figures 1, 2, 3 and 4, where the dashed line is indicated by reference sign DL. The axial direction a of the blade segment 7 is indicated by a dash-dot line in fig. 2.

The first refining surface zone 8a of the blade element 7 comprises first blade teeth 25 and first blade grooves 26 between the first blade teeth 25, and first openings 16a extending through the blade element 7. The first blade tooth 25 has a blade tooth width W₂₅And a tooth angle alpha relative to the axial direction A₂₅And the first blade groove 26 has a blade groove width W₂₆. The first opening 16a has a diameter D_16aIs circular. The second refining surface zone 8b of the blade element 7 comprises second blade teeth 27 and second blade grooves 28 between the second blade teeth 27, and second openings 16b extending through the blade element 7. The second cutter tooth 27 has a cutter tooth width W₂₇And a tooth angle alpha relative to the axial direction A₂₇And the second sipe 28 has a sipe width W₂₈. The second opening 16b has a maximum diameter D_16bIs oval-shaped. As can be seen in the schematic example of fig. 2, the tooth width, the blade groove width, the tooth angle and the shape and size of the openings on the first refining surface zone 8a may differ from the tooth width, the blade groove width, the blade tooth angle and the shape and size of the openings on the second refining surface zone 8 b. The shape of the opening may be, for example, circular, oval, triangular or any polygonal shape. The size of the openings can vary widely from a minimum of the length of the optical fibers to a maximum of even half the length of the element. The openings in the element may be similar to holes or perforations in the intermediate portion between the side edges of the element, or may be similar to notches or cutouts in the side edges of the element.

The tooth width, the groove width, the tooth angle and the shape and size of the openings are refining surface characteristics that vary when the refining surface characteristics are optimized for refining a particular fibrous material composition having particular quality characteristics. When optimizing the surface characteristics, the pitch of the refining surface (i.e. the common width of a single blade tooth and a single blade groove adjacent to the blade tooth), the blade tooth height and the blade groove depth are further characteristics that can be varied. When there is at least one different refining surface characteristic between the refining zones 21a, 21b, this means that at least one of these characteristics at one refining zone 21a, 21b differs from the corresponding characteristic at the other refining zone 21a, 21 b.

According to one embodiment, first fibrous material component FM1 may include virgin hardwood fibrous pulp and second fibrous material component FM2 may include virgin softwood fibrous pulp. In this case, the first blade tooth width W is on the first refining surface area 8a of the blade element 7, i.e. on the first refining zone 21a of the refiner 1₂₅May be, for example, between 1mm and 3mm, and the first slot width W₂₆May for example be between 1mm and 2 mm. On the second refining surface area 8b of the blade element 7, i.e. on the second refining zone 21b of the refiner 1, the second blade tooth width W₂₇May be, for example, between 3mm and 6mm, and the second sipe width W₂₈May for example be between 2mm and 5 mm.

In the refining zone, the angle of the blade teeth is set such that the blade teeth promote the flow of the fibrous material to be refined in the refining zone. In other words, a blade tooth arranged at such an angle will provide a so-called pumping effect on the fibrous material to be refined at the refining zone. Such a cutter tooth angle may be, for example, between 10 degrees and 30 degrees. On the other hand, the intersection angle, i.e. the angle between the cutter teeth in the rotor blade element and the cutter teeth in the stator blade element, may be chosen to be between 10 and 60 degrees, typically between 20 and 40 degrees.

In addition to the refining surface features listed above, the number of teeth and blade gap between stator and rotor may also be different for different refining zones. In any case, the blade gap is less than 1mm in size.

Furthermore, the area of the individual refining zones in the blade element may vary between 10% and 90% with respect to the entire refining surface area of the blade element, the remaining part of the entire refining surface area of the blade element being reserved for at least one other refining zone in the blade element. This provides the possibility of producing different kinds of pulp. For example, when refining hardwood fiber pulp in one refining zone and softwood fiber pulp in another refining zone simultaneously, the area of the refining zone used for refining hardwood fiber pulp may be, for example, between 70% and 80%, and the area of the refining zone used for refining softwood fiber pulp may be between 20% and 30%.

According to another embodiment, at least one of the refining zones 21a, 21b may be designed with a very dense blade tooth-and-groove structure, such as a configuration comprising a pitch of at most 3mm, whereby the cutting edge length provided by the blade teeth of the stator and rotor blade elements 7, 10 in the refiner 1 is very large. This, together with a suitably chosen arrangement of openings in the stator and rotor blade elements 7, 10, achieves the effect that the degree of refining of the fibrous material to be refined is very high, even so high that at least a part of the refined material has the particle size characteristics of nanofibrillar cellulose (nanofibrillar cellulose). The term "nanofibrillar cellulose" refers herein to a collection of cellulose microfibrils or microfibril bundles isolated from a vegetal, especially lignocellulosic material. A synonym for nanofibrillar cellulose (NFC) is e.g. nanofibrillated cellulose, nanocellulose, microfibril cellulose, cellulose nanofibril, nanoscale cellulose, microfibrillated cellulose (MFC) or cellulose microfibril. Depending on the degree of refining, the particle size of the isolated cellulose microfibrils or microfibril bundles is a few nanometers (nm) or micrometers (μm). The average length of the isolated cellulose microfibrils or microfibril bundles may, for example, be 0.2 to 200 μm and the average diameter may, for example, be 2 to 1000 nm. The pitch of the blade elements and the total opening area of the openings in the blade elements may be selected in combination such that the common cutting edge length of the blade teeth in the refiner is even at least 50km per revolution of the rotor 7.

Furthermore, different process parameters are used in the different refining zones 21a, 21 b. The process parameters may include, for example, flow rate, pressure or differential pressure, concentration, pH, and temperature.

The blade element of fig. 2 may also comprise a baffle arrangement between the refining surface zones 8a, 8b, e.g. substantially on the virtual dividing line DL, which prevents the first fibrous material component FM1 to be refined and the second fibrous material component FM2 to be refined in the refining chamber 15 from mixing with each other in the boundary area of the refining zones 21a, 21b, if there is a tendency for such mixing during operation of the refiner and such mixing is undesirable.

The blade element of figure 2 is intended to cover the total length of the stator 6 in the axial direction a of the refiner 1, but the blade element of figure 2 may also consist of two different parts, one of which comprises the first refining surface area 8a and the other of which comprises the second refining surface area 8 b.

Figure 3 shows schematically a side view, partly in cross-section, of another cone refiner 2, which cone refiner 2 can be used for refining lignocellulose-containing wood-based fibre material. Corresponding to the cone refiner 1 of the embodiment of figure 1, the cone refiner 2 of the embodiment of figure 3 comprises a first refining zone 21a on the side of the first end Ea of the refiner 2 and a second refining zone 21b on the side of the second end Eb of the refiner 2. The main differences between the refiner 1 of figure 1 and the refiner 2 of figure 3 are: the refiner 2 comprises a solid rotor blade element 10, i.e. the solid rotor blade element 10 of the refiner 2 does not comprise any openings extending through the blade element 10. The refiner 2 of figure 3 therefore does not comprise any feeding chambers 20a, 20b at the first end Ea of the refiner 2, but only a first feed aggregate portion 18a and a first feed channel 19a at the first end Ea of the refiner 2 and a second feed aggregate portion 18b and a second feed channel 19b at the second end Eb of the refiner 2. The first fibrous material component FM1 is fed into the refining chamber 15 and the first refining zone 21a therein through the first feed channel 19a and the first end Ea of the refining chamber 15. The second fibrous material component FM2 is fed into the refining chamber 15 and the second refining zone 21b therein through the second feed channel 19b and the second end Eb of the refining chamber 15. Otherwise, the construction and operation of the refiner 2 of fig. 3 and the refining surface characteristics may be the same as those disclosed above.

Figure 4 is a very schematic side view, partly in cross-section, of a cylindrical refiner 3, which cylindrical refiner 3 can be used for refining lignocellulose-containing wood-based fibre material. The basic structure and operation of the cylindrical refiner 3 of figure 4 is substantially the same as the above described basic structure and operation of the cone refiner 1 of figure 1, the main difference being the cylindrical form or shape of the stator 6 and the rotor 9 instead of the conical shape. Due to this difference between the form or shape of the stator 6 and the rotor 9, the size of the refining chamber 15 in the cylindrical refiner 3 is adjusted by adjusting the stator diameter, as schematically indicated by the arrow AD in figure 4. The structure and operation of the cylindrical refiner 3 of figure 4 is self-evident from figures 1 and 2 and the above description.

In the refiners 1, 3 of fig. 1, 4, there are two different refining zones 21a, 21b in the axial direction a of the refiner. As shown in fig. 1 and 4, the number of different refining zones in the axial direction a of the refiner 1, 3 can be increased by increasing the number of feed channels for separating the flow of the component of the fibrous material.

Figure 5 shows schematically a side view, partly in cross-section, of a disc refiner 4. The refiner 4 of fig. 5 comprises a first fixed disc refiner element 6a, i.e. a first stator 6a, which first stator 6a has a stator blade element 7a and a refining surface 8 a. The refiner 4 further comprises a rotatable disc refiner element 9, i.e. a rotor 9, the rotor 9 being in close proximity to the first fixed refiner element 6a, the rotor 9 having a first rotor blade element 10a and a refining surface 11a therein. The first rotor blade element 10a and the refining surface 11a therein are directed towards the first stator 6a so that a first refining chamber 15a is formed between the opposing refining surfaces 8a, 11a of the first stator 6a and the rotor 9.

The refiner 4 of fig. 5 further comprises a second fixed disc refining element 6b, i.e. a second stator 6b, which second stator 6b has a stator blade element 7b and a refining surface 8 b. The second stator 6b is arranged immediately adjacent to the rotor 9 on the opposite side of the rotor 9 from the first stator 6a, so that the refining surfaces 8b of the stator blade elements 7b in the second stator 6b are directed towards the rotor 9. The rotor 9 has a second rotor blade element 10b and a refining surface 11b therein. The second rotor blade element 10b and the refining surface 11b therein are directed towards the second stator 6b so that a second refining chamber 15b is formed between the opposing refining surfaces 8b, 11b of the first stator 6b and the rotor 9.

In the disc refiner 4 the refining elements 6a, 6b, 9 and the refining surfaces 6a, 6b, 11a, 11b extend in a radial direction R of the refiner 4, which is substantially perpendicular to the axial direction a of the refiner 4. Correspondingly, a first refining chamber 15a between the first stator 6a and the rotor 9 and a second refining chamber 15b between the second stator 6b and the rotor 9 extend in the radial direction R of the refiner 4. In the radial direction R of the refiner 4, at the opposite ends of the refining elements 6a, 6b, 9 and the refining chambers 15a, 15b, the stators 6a, 6b and the rotor 9 and the refining chambers 15a, 15b have an inner edge IE or inner periphery IE and an outer edge OE or outer periphery OE, respectively.

Furthermore, in the refiner 4 of fig. 5, there is a first feed aggregate portion 18a and a first feed channel 19a, arranged to feed a first fibrous material component FM1 into the first refining chamber 15a through an inner edge IE of the first refining chamber 15 a. Furthermore, there is a second feed plenum 18b and a second feed channel 19b arranged to feed a second fibrous material component FM2 into the second refining chamber 15b through the inner edge IE of the second refining chamber 15 b. The quality of the second fibrous material component FM2 may be different from the quality of the first fibrous material component FM1, or it may be the same fibrous material component. The refining surface characteristics of the refining surface 8a of the first stator 6a and the first refining surface 11a of the rotor 9 are selected according to the refining requirements of the first fibrous material component FM1, forming a first refining chamber 15a between the refining surface 8a and the first refining surface 11a, whereby the first refining chamber 15a provides a first refining zone 21a of the refiner 4. The refining surface characteristics of the refining surface 8b of the second stator 6b and the refining surface 11b of the rotor 9 are selected according to the refining requirements of the second fibrous material component FM2, forming a second refining chamber 15b between the refining surface 8b and the second refining surface 11b, whereby the second refining chamber 15b provides a second refining zone 21b of the refiner 4. Due to the different refining requirements of the different quality fibre material components FM1, FM2, at least one refining surface characteristic in the first refining chamber 15a differs from the corresponding refining surface characteristic in the second refining chamber 15 b.

Furthermore, in the refiner 4 of fig. 5, there are two separate discharge chambers 22a, 22 b. The first discharge chamber 22a is intended to receive the first fibrous material component FM1 refined in the first refining chamber 15a, as schematically indicated by arrow FM 1. The second discharge chamber 22b is intended to receive the second fibrous material component FM2 refined in the second refining chamber 15b, as schematically indicated by arrow FM 2. The refined first fibrous material component FM1 is discharged from the first discharge chamber 22a through the first discharge channel 23a and the first discharge plenum 24 a. The refined second fibrous material component FM2 is discharged from the second discharge chamber 22b through the second discharge channel 23b and the second discharge plenum 24 b. Thus, the refined first fibrous material component FM1 and the refined second fibrous material component FM2 are supplied to the subsequent treatment as separate fluids.

In the refiner of fig. 5, there are two discharge channels 23a, 23b corresponding to the refining zones 21a, 21b for discharging from the refiner the fibrous material components that have been subjected to different refining effects in different refining zones 21a, 21b as separate fluids. Usually, the number of discharge channels is the same as the number of refining zones, i.e. one discharge channel per refining zone, but it is not excluded that a refining zone has a higher number of discharge channels. Such refiners are particularly suitable for pulp manufacturing applications where a suitable volume of different fiber material components is to be produced, allowing the use of different fiber material components with a suitable number of refiners, which still have a refining effect optimized for the specific fiber material component.

In the refiner 4 of figure 5, instead of separate discharge chambers 22a, 22b, separate discharge channels 23a, 23b and separate discharge-aggregate parts 24a, 24b, it is also possible to use one common discharge chamber 22, one common discharge channel 23 and one common discharge-aggregate part 24. Correspondingly, in the refiners 1, 3, 4 of fig. 1, 3 and 4, instead of one common discharge chamber 22, one common discharge channel 23 and one common discharge aggregate portion 24, separate discharge chambers 22a, 22b, separate discharge channels 23a, 23b and separate discharge aggregate portions 24a, 24b may also be used.

The refiner 4 of figure 5 is a double disc refiner comprising two stators and a rotor between the two stators, whereby two different refining chambers 15a, 15b are provided in the refiner. A similar form of construction can also be used for cone refiners and cylindrical refiners, whereby there are two conical or cylindrical stators and a conical or cylindrical rotor between them, in order to provide two different refining chambers 15a, 15b, each providing a respective refining zone 21a, 21b with at least one different refining surface feature therein. Such refiners thus comprise a first fixed refining element and a rotatable refining element within and substantially opposite the first fixed refining element such that a first refining chamber is formed between the opposing refining surfaces of the first fixed refining element and the rotatable refining element, the first refining chamber forming a first refining zone; and a second fixed refining element within and substantially opposite the rotatable refining element such that a second refining chamber is formed between the opposing refining surfaces of the rotatable refining element and the second fixed refining element, the second refining chamber forming a second refining zone, and wherein at least one refining surface characteristic at the second refining zone is different from a corresponding at least one refining surface characteristic at the first refining zone. In such a conical or cylindrical refiner, the first feed channel may be arranged to feed the first fibrous material component into the first refining chamber through at least one end of the first refining chamber, and the second feed channel may be arranged to feed the second fibrous material component into the second refining chamber through at least one end of the second refining chamber. The number of different refiner chambers in such a conical and cylindrical refiner and the disc refiner of figure 5 can be further increased by increasing the number of stators and rotors in the refiner.

It is obvious to a person skilled in the art that with the advancement of technology, the inventive concept may be implemented in various ways. The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.