Refiner

Abstract

To provide a novel refiner and method for refining a lignocellulose-containing fibrous material.SOLUTION: A refiner (1) for refining a lignocellulose-containing fibrous material includes at least two refining elements (6) positioned practically opposite to each other, each of which includes at least one refining surface (8, 11) having a blade bar and a blade groove. The refining surfaces of the two opposed refining elements face each other and form a refining chamber (15) between them that houses the fibrous material to be refined. The refiner further includes at least two feed channels (19a, 19b), at least two refining zones (21a, 21b), and a discharge channel (23).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a refiner and method for refining lignocellulose-containing fibrous material. [Background technology]

[0002] In the manufacture of paper and board, one or more lignocellulosic wood-based fibre material fractions of different qualities may be mixed to produce a paper or paperboard web. The mixing of fibre material fractions of different qualities is done due to the need to obtain a combination of different types of properties in the final product, for example a certain tensile strength with a certain grammage. The different quality fibre material fractions may include different recycled fibre materials, for example virgin hardwood and softwood based fibre pulps, and long and short fibre pulps from Old Corrugated Container (OCC).

[0003] Generally, mixed pulp is produced by mixing at least two fiber material fractions of different qualities from separate storage tanks, with each specific storage tank being reserved for a single fiber material fraction of a specific quality. However, a single fiber material may also contain different qualities, such as OCC, which contains both long and short fiber fractions. Considering that the refining of the fiber material is performed before feeding the fiber material to be refined into the storage tank, each different fiber material fraction is refined in a refiner specially designed to have refining surface characteristics optimized for that specific fiber material fraction. This means that each refined fiber material fraction has a high quality, but the number of refiners increases according to the number of different fiber material fractions to be mixed.

[0004] The number of refiners may be reduced by first blending at least two fibrous material fractions of different quality together or by having one fibrous material with a large fiber length distribution, such as OCC, and then refining the fibrous material pulp in a single refiner. However, in this case, the refining surface characteristics of the refiner are a compromise based on the refining needs of the fibrous material fractions forming the pulp. Therefore, the quality of the pulp blended after refining is not necessarily as high as the quality of the pulp formed by blending at least two separately refined fibrous material fractions as disclosed above. Summary of the Invention [Problem to be solved by the invention]

[0005] It is an object of the present invention to provide a novel refiner and method for refining lignocellulose-containing fibrous material. [Means for solving the problem]

[0006] The invention is characterized by the features of the independent claims.

[0007] The idea of ​​the present invention is to use a single refiner to simultaneously refine at least two streams of at least one fiber material fraction in different refining zones in a single refiner, the refining surface characteristics of the different refining zones being specially designed taking into account the fiber material fraction to be refined in the refining zone as well as taking into account the intended refining effect to which the fiber material fraction is to be exposed in the refining zone. Thus, it is possible to feed at least two streams of fiber material into the refiner, the two streams being one and the same fiber material fraction or different fiber material fractions of different qualities.

[0008] An advantage of the present invention is that it is possible with a single refiner to simultaneously refine at least one fibrous material fraction with different refining effects to be exposed to the at least one fibrous material fraction, whereby the fibrous material portions subjected to different refining effects may be directed, for example, to different layers of a paper or substrate web to be produced or to different processes. Refiners of this kind are particularly useful in applications where the amount or volume of fibrous material fraction required for the production of paper or paperboard is modest.

[0009] Some embodiments of the invention are disclosed in the dependent claims.

[0010] The present invention will now be described in more detail by way of preferred embodiments with reference to the accompanying drawings. [Brief description of the drawings]

[0011] [Figure 1] 1 shows a schematic cross-sectional side view of a conical refiner. [Diagram 2] 2 shows a schematic plan view of a blade element applicable for use in the conical refiner of FIG. 1; [Diagram 3] 2 shows a schematic cross-sectional side view of another conical refiner; [Figure 4] 1 shows a schematic cross-sectional side view of a conical refiner. [Diagram 5] 1 shows a side view of a disc refiner in cross section, diagrammatically. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] For clarity, the drawings illustrate some embodiments of the invention in a simplified manner, and like reference numbers identify like elements in the figures.

[0013] 1 is a highly schematic, partially cross-sectional side view of a conical refiner 1 that may be used to refine lignocellulose-containing wood-based fiber material. Refiner 1 has a first end Ea of smaller diameter and a second end Eb of larger diameter.

[0014] Refiner 1 includes a stationary refining element 6, i.e., stator 6, having a first end facing toward a first end Ea of refiner 1 and a second end facing toward a second end Eb of refiner 1, and therefore, for the sake of clarity, reference sign Ea is also used to denote the first end of stator 6 and reference sign Eb is also used to denote the second end of stator 6. Stator 6 is supported on a frame structure 5 of refiner 1.

[0015] The stator 6 includes a number of stator blade elements 7 having a refining surface 8, the refining surface 8 of each stator blade element 7 contributing to provide a complete refining surface of the stator 6. The stator blade elements 7 have a first end facing towards a first end Ea of the refiner 1 and a second end facing towards a second end Eb of the refiner 1, and therefore, for 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.

[0016] According to one embodiment of the stator 6, the stator 6 may include only one blade element 7 of conical shape extending over the entire circumference of the stator 6, such that the refining surface 8 of the single blade element provides a completely uniform refining surface of the stator 6. According to another embodiment of the stator 6, the stator 6 may include at least two segmented blade elements, i.e. blade segments, arranged adjacent to each other, whereby the refining surfaces 8 of the originally separate segmented blade elements together provide a completely uniform refining surface of the stator 6. Thus, the term blade element, when referring to the stator 6 of the refiner 1, may refer to a single blade element providing the complete refining surface of the stator 6, or it may refer to a blade segment providing only a part of the complete refining surface of the stator 6. For the sake of clarity, the same reference number 8 may be used below to refer to both the refining surface 8 of a single blade element 7 for the stator 6 and the complete refining surface 8 of the stator 6. The refining surface 8 of the stator 6 typically comprises blade bars and blade grooves between the blade bars, an embodiment with several blade bars and blade grooves being shown later in FIG.

[0017] The refiner 1 further includes a rotatable refining element 9, i.e., rotor 9, having a first end facing toward the first end Ea of the refiner 1 and a second end facing toward the second end Eb of the refiner 1, and therefore, for the sake of clarity, the reference symbol Ea is also used to indicate the first end of the rotor 9 and the reference symbol Eb is also used to indicate the second end of the rotor 9.

[0018] The rotor 9 includes a number of rotor blade elements 10 having a refining surface 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 elements 10 have a first end facing towards a first end Ea of the refiner 1 and a second end facing towards a second end Eb of the refiner 1; therefore, for clarity, the reference sign Ea is also used to denote the first end of the rotor blade element 10 and the reference sign Eb is also used to denote the second end of the rotor blade element 10.

[0019] According to one embodiment of the rotor 9, the rotor 9 may include only one blade element 10 of conical shape extending over the entire circumference of the rotor 9, such that the single blade element provides a completely uniform refining surface 11 of the rotor 9. According to another embodiment of the rotor 9, the rotor 9 may include at least two segmented blade elements, i.e. blade segments, arranged adjacent to each other, whereby the refining surfaces 11 of the originally separate segmented blade elements together provide a completely uniform refining surface of the rotor 9. Thus, the term blade element, when referring to the rotor 9 of the refiner 1, refers to a single blade element providing the complete refining surface of the rotor 9, or to a blade segment providing only a part of the complete refining surface of the rotor 9. For clarity, the same reference number 11 may be used below to indicate the refining surface 11 of a single blade element 9 of the rotor 9 and the complete refining surface 11 of the rotor 9. The refining surface 11 of the rotor 9 typically comprises blade bars and blade grooves between the blade bars, as shown later in FIG. 2.

[0020] The rotor 9 comprises a hub 12 on which at least one rotor blade element 10 is supported. The hub 12 is shown in a highly simplified manner in Figure 1 and subsequently in Figures 3 and 4. The hub 12 of the rotor 9 is connected to a shaft 13. The shaft 13 is connected to a motor 14, depicted very diagrammatically, which is arranged to rotate the shaft 13, and thereby the rotor 9, for example in a rotational direction indicated by the arrow RD.

[0021] The refiner 1 may comprise a loading device, not shown in FIG. 1 for clarity, which may be connected to a shaft 13 for moving the rotor 9 back and forth, as shown diagrammatically by the arrow AD, in order to adjust the distance between the stator 6 and the rotor 9, i.e. to adjust the size of the refining chamber 15 or blade gap 15 formed between the stator 6 and the rotor 9 or blade elements 7, 10. The refining chamber 15 thus forms a volume in which the fibrous material is refined. The size of the refining chamber 15 relative to the other components of the refiner is exaggerated in all figures. The refining chamber 15 has a first end facing towards the first end Ea of the refiner 1 and a second end facing towards the second end Eb of the refiner 1, therefore, for 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.

[0022] The stator blade element 7 further includes openings 16a, 16b extending therethrough, and the rotor blade element 10 includes openings 17a, 17b extending therethrough, such that 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, as indicated diagrammatically by arrow A in FIG. 1, the openings 16a, 16b in the stator blade element 7 are at substantially the same axial position as the openings 17a, 17b in the rotor blade element 10 when the blade elements 7, 10 are opposed to each other. Alternatively, the openings 16a, 16b in the stator blade element 7 can be at least partially at a different axial position relative to the axial position of the openings 17a, 17b in the rotor blade element 10.

[0023] 1 , refiner 1 includes, at a first end Ea of refiner 1, a first feed aggregate 18a and a first feed channel 19a connected to first feed aggregate 18a, through which a first fiber material fraction, indicated generally by arrow FM1, is fed to a first feed chamber 20a provided by an internal volume of rotor 9 on the side of first end Ea of rotor 9. First feed chamber 19a extends from first end Ea of rotor 9 towards, but not to, second end Eb of rotor 9.

[0024] The refiner 1 further comprises, at the first end Ea of the refiner 1, a second feed assembly 18b and a second feed channel 19b connected to the second feed assembly 18b, through which a second fibrous material fraction, indicated generally by the arrow FM2, is fed to a second feed chamber 20b provided by an internal volume of the rotor 9 on the side of the second end Eb of the rotor 9. The second feed chamber 19b extends from the second end Eb of the rotor 9 towards the first end Ea of the rotor 9, but does not extend all the way to the first end Ea of the rotor 9.

[0025] Furthermore, in the embodiment of FIG. 1, the refining surfaces 8, 11 in the stator 6 and the rotor 9 are designed or configured in the axial direction A of the refiner 1 such that in the refining chamber 15 there are two different refining zones with at least one different refining surface characteristic in the axial direction A of the refiner 1, namely a first refining zone 21a indicated by the arrow 21a at the side of the first end Ea of the refiner 1 and a second refining zone 21b indicated by the arrow 21b at the side of the second end Eb of the refiner 1. In the axial direction A of the refiner 1, the first refining zone 21a is substantially present at a location corresponding to the first feed chamber 20a of the refiner 1, and the second refining zone 21b is substantially present at a location corresponding to the second feed chamber 21b of the refiner 1. As briefly alluded to above, at least one refining surface characteristic in the first refining zone 21a is selected to be different from the respective refining surface characteristic in the second refining zone 21b. Generally, this means that the refining surface properties of the stator and rotor blade elements 7, 10 in the first refining zone 21a are designed from the perspective of the refining effect intended to be achieved according to a first fiber material fraction FM1 to be refined in the first refining zone 21a, and the refining surface properties of the stator and rotor blade elements 7, 10 in the second refining zone 21b are designed from the perspective of the refining effect intended to be achieved according to a second fiber material fraction FM2 to be refined in the second refining zone 21b.

[0026] The operation of refiner 1 of FIG. 1 is as follows.

[0027] The first fiber material fraction FM1 flows from the first feed chamber 20a through the first opening 17a of the first refining zone 21a into the refining chamber 15, whereby the first fiber material fraction FM1 is substantially refined in the refining chamber 15 of the first refining zone 21a. The first opening 16a thus connects the first feed chamber 20a to the refining chamber 15 in the first refining zone 21a. In the refining chamber 15 in the first refining zone 21a, the first fiber material fraction FM1 is subjected to a refining effect provided by the refining surface areas of the stator and rotor blade elements 7, 10, respectively. The first fiber material fraction FM1 refined in the refining chamber 15 in the first refining zone 21a is discharged from the refining chamber 15 through the first opening 16a into the discharge chamber 22 behind the stator blade element 7. Thus, the first opening 16a connects the refining chamber 15 in the first refining zone 21a to the discharge chamber 22. The flow of the first fiber material fraction FM1 into the refining chamber 15 in the first refining zone 21a and the flow of the refined first fiber material fraction FM1 out of the refining chamber 15 are also indicated diagrammatically by arrows FM1.

[0028] The second fiber material fraction FM2 flows from the second feed chamber 20b into the refining chamber 15 through the second opening 17b of the second refining zone 21b, whereby the second fiber material fraction FM2 is substantially refined in the refining chamber 15 in the second refining zone 21b. The second opening 17b thus connects the second feed chamber 20a to the refining chamber 15 in the second refining zone 21b. The second fiber material fraction FM2 is subjected to a refining effect provided by the refining surface areas of the stator and rotor blade elements 7, 10 in the refining chamber 15 in the second refining zone 21b. The second fiber material fraction FM2 refined in the refining chamber 15 in the second refining zone 21b is discharged from the refining chamber 15 to the discharge chamber 22 through the second opening 16b. Thus, the second opening 16b connects the refining chamber 15 in the second refining zone 21b to the discharge chamber 22. The flow of the second fiber material fraction FM2 into the refining chamber 15 and the flow of the refined first fiber material fraction FM2 from the refining chamber 15 in the second refining zone 21b are also indicated diagrammatically by arrows FM2.

[0029] In the discharge chamber 22, the refined first fiber material fraction FM1 and the refined second fiber material fraction FM2 are combined, whereby they are at least partially mixed with each other. The combined stream of the refined first fiber material fraction FM1 and the refined second fiber material fraction FM2 is discharged from the refiner 1 through a discharge channel 23 connected to the discharge chamber 22 and through a discharge assembly 24 connected to the discharge channel 23, as shown diagrammatically by the arrows designated with the reference sign FM1+FM2. The combined stream of the refined first fiber material fraction FM1 and the refined second fiber material fraction FM2 is thus fed as one stream to further processing.

[0030] Thus, in the refiner 1 there are two refining zones 21a, 21b, such that the first refining zone 21a is specially designed to refine the first fiber material fraction FM1 and the second refining zone 21b is specially designed to refine the second fiber material fraction FM2. The properties of the particular refining zones 21a, 21b are thus provided by a special design of the refining surfaces 8, 11 of the stator and rotor blade segments 7, 10, which contribute to providing the refining zones 21a, 21b. The advantage of this is that a single refiner may be used to simultaneously refine two separate fiber material fractions having at least one different qualitative property, whereby a particular part of the refining surfaces 8, 11 of the stator and rotor blade segments 7, 10 is optimized for refining a particular fiber material fraction. In other words, it is possible to provide a single refiner that optimally refines two streams of fibrous material simultaneously by using a first refining zone 21a having at least one different refining surface characteristic for each refining surface characteristic in the second refining zone 21b.

[0031] According to an embodiment, the first fiber material fraction FM1 and the second fiber material fraction FM2 have one and the same fiber material, i.e. the same quality, where different parts of the same fiber material may be subjected to different refining effects in the different refining zones 21a, 21b.

[0032] According to another embodiment, the second fiber material fraction FM2 is qualitatively different from the first fiber material fraction FM1. By the definition that the second fiber material fraction FM2 is qualitatively different from the first fiber material fraction FM1, it is meant that at least one of the raw material, particle size, fiber length, freeness, residual lignin content, and any other properties of the second fiber material fraction FM2 is different from the respective properties of the first fiber material fraction FM1. The hub 12 in the rotor 9 is configured such that the first fiber material fraction FM1 in the first feed chamber 20a and the second fiber material fraction FM2 in the second feed chamber 20b do not mix with each other in the rotor 9.

[0033] According to a further embodiment, the second fibrous material fraction FM2 may be the first fibrous material fraction FM1 refined in the first refining zone 21a and discharged from the first refining zone 21a. According to this embodiment, the refiner may provide a two-stage refining for the first fibrous material fraction FM1.

[0034] FIG. 2 shows, in schematic form, a plan view of a blade element applicable for use in the stator 6 of the refiner 1 of FIG. 1. FIG. 2 shows a single segmental blade element 7 intended to provide a portion of the complete refining surface 8 of the stator 6. FIG. 2 is intended only to illustrate possible different refining surface characteristics between the first refining zone 21a and the second refining zone 21b. For clarity, only the segmental blade element 7 for the stator 6 is disclosed in FIG. 2, but the same design principles apply to the respective blade elements 10 of the rotor 9 that provide the counterparts of the stator blade element 7.

[0035] The blade element 7 of FIG. 2 comprises a first end Ea facing towards the first end Ea of the stator 6, a second end Eb facing towards 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 area 8 of the stator 6 in the second refining zone 21b of the refiner 1. An imaginary dividing line between the first refining surface area 8a and the second refining surface area 8b is shown in FIGS. 1, 2, 3 and 4 by means of a dashed line, denoted by the reference DL. The axial direction A of the blade segment 7 is indicated by a dot-and-dash line in FIG.

[0036] The first refining surface 8a of the blade element 7 includes a first blade bar 25 and a first blade groove 26 therebetween, as well as a first opening 16a extending through the blade element 7. The first blade bar 25 has a width W 25と , the angle α of the blade bar relative to the axial direction A 25 and the first blade groove 26 has a blade groove width W 26 The first opening 16a has a diameter of D 16a The second refining surface area 8b of the blade element 7 includes a second blade bar 27 and a second blade groove 28 therebetween, as well as a second opening 16b extending through the blade element 7. The second blade bar 27 has a blade bar width W 27 and the angle α of the blade bar with respect to the axial direction A. 27 and the second blade groove 28 has a blade groove width W 28 The second opening 16b has a diameter of D 16b In the schematic example of FIG. 2, it can be seen that the width of the blade bar, the width of the blade groove, the angle of the blade bar, and the shape and size of the openings in the first refining surface area 8a may differ from the width of the blade bar, the width of the blade groove, the angle of the blade bar, and the shape and size of the openings in the second refining surface area 8b. The shape of the openings may be, for example, circular, elliptical, triangular, or any polygonal shape. The size of the openings may vary greatly from the minimum of the length of the fiber to the maximum half of the length of the element. The openings in the elements may be like holes or perforations located in the middle part between the side edges of the element, but they may also be like recesses or notches in the side edges of the element.

[0037] The width of the blade bar, the width of the blade groove, the angle of the blade bar, and the shape and size of the opening are some refining surface properties that may be different when the refining surface properties are optimized for refining a specific fiber material fraction having specific qualitative properties. The pitch of the refining surface, i.e. the common width of a single blade bar and a single blade groove adjacent to the blade bar, the height of the blade bar, and the depth of the blade groove, may be further properties that may be different when the refining surface properties are optimized. When it is described above that the refining zones 21a, 21b have at least one different refining surface property with respect to each other, it means that at least one of those properties in one refining zone 21a, 21b is different from the corresponding property in the other refining zone 21a, 21b.

[0038] According to an embodiment, the first fibrous material fraction FM1 may comprise undeveloped hardwood fiber pulp, and the second fibrous material fraction FM2 may comprise undeveloped softwood fiber pulp. In that case, in the first refining area 8a of the blade element 7, i.e. in the first refining zone 21a of the refiner 1, the width W 25 can be, for example, between 1 mm and 3 mm, and the width W of the first blade groove 26 can be, for example, between 1 mm and 2 mm. In the second refining surface area 8b of the blade element 7, i.e. in the second refining zone 21b of the refiner 1, the width W 27 can be, for example, between 3 mm and 6 mm, and the width W of the second blade groove 28 can be, for example, 2 mm to 5 mm.

[0039] The blade bars in the refining zone are angled such that they promote the flow of the fibrous material to be refined in the refining zone. In other words, the blade bars set at such an angle provide a so-called pumping effect on the fibrous material to be refined in the refining zone. The angle of such blade bars may be, for example, between 10 and 30 degrees. On the other hand, the crossing angle, i.e. the angle between the blade bars of the rotor blade element and the blade bars of the stator blade element, may be selected to be between 10 and 60 degrees, typically between 20 and 40 degrees.

[0040] In addition to the abovementioned refining surface characteristics, the number of blade bars, as well as the blade gap between the stator and rotor, may also differ in the different refining zones. In all cases, the size of the blade gap is less than 1 mm.

[0041] Furthermore, the area of ​​a single refining zone in a blade element relative to the total refining surface area of ​​the blade element may vary between 10% and 90%, and the remainder of the refining surface area of ​​the blade element is intended to be reserved for at least one other refining zone in the blade element. This provides the possibility of producing different types of pulp. For example, when simultaneously refining hardwood fiber pulp in one refining zone and softwood fiber pulp in another refining zone, the area of ​​the refining zone intended to refine hardwood fiber pulp is, for example, between 70% and 80%, and the area of ​​the refining zone intended to refine softwood fiber pulp is, respectively, between 20% and 30%.

[0042] According to a further embodiment, at least one of the refining zones 21a, 21b may be designed with a very dense blade bar-blade groove-configuration, such as a configuration with a pitch of at most 3 mm, whereby the length of the cutting edge provided by the blade bars of the stator and rotor blade elements 7, 10 in the refiner 1 is very high. This, in common with a suitably selected opening configuration in the stator and rotor blade elements 7, 10, may have the effect that the degree of comminution of the fibrous material to be refined is very high, so high that at least a part of the material to be refined has the particle size characteristic of nanofibrillar cellulose. In this specification, the term "nanofibrillar cellulose" refers to a collection of separate cellulose microfibrils or microfibril bundles originating from plant-based fibrous materials, in particular wood fibrous materials. Synonyms of nanofibrillar cellulose (NFC) are, for example, nanofibrillated cellulose, nanocellulose, microfibril cellulose, cellulose nanofibers, nanoscale cellulose, microfibrillated cellulose (MFC) or cellulose microfibrils. Depending on the degree of comminution, the particle size of the individual cellulose microfibrils or microfibril bundles is a few nanometers (nm) or a few micrometers (μm). The average length of the individual cellulose microfibrils or microfibril bundles may be, for example, 0.2 to 200 μm and the average diameter may be, for example, 2 to 1000 nm. The pitch of the blade elements and the total open area of ​​the openings of the blade elements may be selected in combination such that the length of the common cutting edge of the blade bars in the refiner is even at least 50 km per revolution of the rotor 7.

[0043] Additionally, there may be different process parameters utilized in the different refining zones 21a, 21b. The process parameters may include, for example, flow rate, pressure or pressure differential, consistency, pH value, and temperature.

[0044] The blade element of Figure 2 may include a dam arrangement between the refining surface areas 8a, 8b, for example substantially at the imaginary dividing line DL, which prevents the first fibrous material fraction FM1 to be refined and the second fibrous material fraction FM2 to be refined from mixing with each other in the chamber 15 in the boundary region of the refining zones 21a, 21b, if there is any tendency for mixing as follows during operation of the refiner and mixing is undesirable.

[0045] Although the blade element of FIG. 2 is intended to cover the entire length of the stator 6 in the axial direction A of the refiner 1, the blade element of FIG. 2 can also be constructed from two different pieces, one including a first refining surface area 8a and the other including a second refining surface area 8b.

[0046] Figure 3 shows a schematic side view, partially in section, of another conical refiner 2, which may be used for refining wood fiber material containing lignocellulose. Corresponding to the conical refiner 1 of the embodiment of Figure 1, the conical refiner 2 of the embodiment of Figure 3 comprises a first refining zone 21a at a first end Ea of the refiner 2 and a second refining zone 21b at a second end Eb of the refiner 2. The main difference between the refiner 1 of Figure 1 and the refiner 2 of Figure 3 is that the refiner 2 comprises a solid rotor blade element 10, i.e., the rotor blade element 10 of the refiner 2 does not comprise any openings extending through the blade element 10. As a result, the refiner 2 of Fig. 3 does not include any feed chambers 20a, 20b, but only includes a first feed assembly 18a and a first feed channel 19a at a first end Ea of the refiner 2, and a second feed assembly 18b and a second feed channel 19b at a second end Eb of the refiner 2. The first fibrous material fraction FM1 is intended to be fed through the first feed channel 19a and the first end Ea of the refining chamber 15 to the refining chamber 15 and a first refining zone 21a therein. The second fibrous material fraction FM2 is intended to be fed through the second feed chamber 19b and the second end Eb of the refining chamber 15 to the refining chamber 15 and a second refining zone 21b therein. Otherwise, the structure and operation of the refiner 2 of Fig. 3 and the characteristics of the refining surface may be similar to those disclosed above.

[0047] FIG. 4 is a highly schematic side view, partially in section, of a cylindrical refiner 3 that may be utilized to refine wood fiber material containing lignocellulose. The basic structure and operation of the cylindrical refiner 3 of FIG. 4 is substantially similar to that of the conical refiner 1 of FIG. 1 above, with the main difference being the cylindrical, instead of conical, form or shape of the stator 6 and rotor 9. Because of this difference between the form or shape of the stator 6 and rotor 9, the size of the refining chamber 15 is adjusted in the cylindrical refiner 3 by adjusting the stator diameter, as shown diagrammatically by arrows AD in FIG. 4. The structure and operation of the cylindrical refiner 3 of FIG. 4 is self-explanatory in view of the diagrams of FIGS. 1 and 2 and the above description.

[0048] Refiners 1 and 3 of Figures 1 and 4 have two different refining zones 21a, 21b in the refiner's axial direction A. As in Figures 1 and 4, the number of different refining zones in the axial direction A of refiners 1 and 3 may be increased by increasing the number of feed channels for the flow of the separate fibrous material fractions.

[0049] FIG. 5 shows a schematic side view of a disc refiner 4, partly in section. The refiner 4 of FIG. 5 includes a first stationary disc-shaped refining element 6a, i.e. a first stator 6a, having a stator blade element 7a and a refining surface 8a thereon. The refiner 4 further includes a rotatable disc-shaped refining element 9, i.e. a rotor 9, next to the first stationary refining element 6a, the rotor 9 having a first rotor blade element 10a and a refining surface 11a thereon. The first rotor blade element 10a and the refining surface 11a thereon are oriented towards the first stator 6a such that a first refining chamber 15a is formed between the opposing refining surfaces 8a, 11a of the first stator 6a and the rotor 9.

[0050] The refiner 4 of FIG. 5 further includes a second stationary disk-shaped refining element 6b, i.e. a second stator 6b having a stator blade element 7b and a refining surface 8b therein. The second stator 6b is disposed next to the rotor 9 on the opposite side of the rotor 9 to the first stator 6a, such that the refining surface 8a of the stator blade element 7b in the second stator 6b is oriented 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 oriented towards the second stator 6b such that a second refining chamber 15b is formed between the opposing refining surfaces 8b, 11b of the second stator 6b and the rotor 9.

[0051] In the disc-shaped 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, the stators 6a, 6b and the rotor 9, as well as the refining chambers 15a, 15b, have an inner edge IE or inner circumference IE and an outer edge OE or outer circumference OE at the opposite ends of the refining elements 6a, 6b, 9 and the refining chambers 15a, 15b, respectively.

[0052] 5 further includes a first feed assembly 18a and a first feed channel 19a arranged to feed a first fiber material fraction FM1 into the first refining chamber 15a through the inner edge IE of the first refining chamber 15a. Further includes a second feed assembly 18b and a second feed chamber 19b arranged to feed a second fiber material fraction FM2 into the second refining chamber 15b through the inner edge IE of the second refining chamber 15b. The second fiber material fraction FM2 may be qualitatively different from the first fiber material fraction FM1 or they may be one and the same fiber material fraction. The refining surface characteristics of the refining surface 8a of the first stator 6a and the first refining surface 11b of the rotor 9, which form a first refining chamber 15a therebetween, are selected according to the refining needs of the first fiber material fraction FM1, 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 second refining surface 9b of the rotor 9, which form a second refining chamber 15b therebetween, are selected according to the refining needs of the second fiber material fraction FM2, whereby the second refining chamber 15b provides a second refining zone 21b of the refiner 4. Due to the different refining needs of the qualitatively different fiber material fractions FM1, FM2, at least one refining surface characteristic in the first refining chamber 15a is different from the respective refining surface characteristic in the second refining chamber 15b.

[0053] Furthermore, the refiner 4 of FIG. 5 has two separate discharge chambers 22a, 22b. The first discharge chamber 22a is intended to receive the first fiber material fraction FM1 refined in the first refining chamber 15a, as also shown diagrammatically with the arrow FM1. The second discharge chamber 22b is intended to receive the second fiber material fraction FM2 refined in the second refining chamber 15b, as also shown diagrammatically with the arrow FM2. The refined first fiber material fraction FM1 is discharged from the first discharge channel 22a through the first discharge channel 23a and the first discharge assembly 24a. The refined second fiber material fraction FM2 is discharged from the second discharge channel 22b through the second discharge channel 23b and the second discharge assembly 24b. Thus, the refined first fibre material fraction FM1 and the refined second fibre material fraction FM2 are fed as separate streams to further processing.

[0054] Thus, in the refiner of FIG. 5, there are discharge channels 23a, 23b for the refining zones 21a, 21b to discharge the fibrous material fractions that have undergone different refining effects in the different refining zones 21a, 21b as separate streams from the refiner. Typically, the number of discharge channels is the same as the number of refining zones, i.e., one discharge channel for each refining zone. However, a higher number of discharge channels in any refining zone is not excluded. This type of refiner is particularly useful in pulp manufacturing applications where a moderate amount of different fibrous material fractions is to be produced, allowing the use of different fibrous material fractions in a moderate number of refiners, but still with an optimized refining effect that a particular fibrous material fraction has undergone.

[0055] In refiner 4 of Figure 5, instead of separate discharge chambers 22a, 22b, separate discharge chambers 23a, 23b, and separate discharge assemblies 24a, 24b, one common discharge chamber 22, one common discharge channel 23, and one common discharge assembly 24 can be utilized. Correspondingly, in refiners 1, 2, 3 of Figures 1, 3, and 4, instead of one common discharge chamber 22, one common discharge channel 23, and one common discharge assembly 24, separate discharge chambers 22a, 22b, separate discharge channels 23a, 23b, and separate discharge assemblies 24a, 24b can also be utilized.

[0056] The refiner 4 of Figure 5 is a dual disc refiner including two stators and a rotor therebetween, thereby providing two different refining chambers 15a, 15b within the refiner. A similar type of construction may be utilized in conical and cylindrical refiners, whereby there are two conical or cylindrical stators and a conical or cylindrical rotor therebetween to provide two different refining chambers 15a, 15b, each refining chamber providing a respective refining zone 21a, 21b having at least one different refining surface characteristic. Thus, this type of refiner includes a first stationary refining element, a rotatable refining element within the first stationary refining element and substantially opposite the first stationary refining element, such that a first refining chamber forming a first refining zone is formed between the opposing refining surfaces of the first stationary refining element and the rotatable refining element, and a second stationary refining element within the rotatable refining element and substantially opposite the rotatable refining element, such that a second refining chamber forming a second refining zone is formed between the rotatable refining element and the second stationary refining element, and at least one refining surface characteristic in the second refining zone is different from at least one respective refining surface characteristic in the first refining zone. In this type of conical or cylindrical refiner, the first feed chamber may be configured to feed a first fraction of fibrous material into the first refining chamber through at least one end of the first refining chamber, and the second feed chamber may be configured to feed a second fraction of fibrous material into the second refining chamber through at least one end of the second refining chamber. The number of different refiner chambers in this type of conical and cylindrical refiner, as well as in the type of disc refiner of Figure 5, may be further increased by increasing the number of stators and rotors in the refiner.

[0057] It is obvious to a person skilled in the art that as technology advances, the inventive concept may be implemented in various ways. The invention and its embodiments are not limited to the above examples but may vary within the scope of the claims.

Claims

1. 1. A refiner for refining fibrous material containing lignocellulose, comprising: at least two substantially oppositely positioned refining elements, each of the refining elements including at least one refining surface having a blade bar and a blade groove, the refining surfaces of the two substantially oppositely positioned refining elements facing each other and forming a refining chamber therebetween for receiving a fibrous material to be refined; at least two feed channels for feeding at least one fraction of fibrous material to be refined into the refiner; at least two refining zones, each of which is intended to refine one fiber material fraction of the at least one fiber material fraction, having at least one different refining surface characteristic between the refining zones; a discharge channel to the refining zone for discharging a fraction of the fibrous material refined in the refining zone from the refiner as a separate stream; the refiner is a conical refiner comprising a conical refining element having a first end with a smaller diameter and a second end with a larger diameter; Refiner.

2. The refiner is a first feed channel for feeding a first fraction of fibrous material into the refiner; a second feed channel for feeding a second fraction of fibrous material into the refiner; a first refining zone for refining the first fiber material fraction and a second refining zone for refining the second fiber material fraction, The refiner of claim 1 .

3. The refiner includes a stationary refining element and a rotatable refining element within the stationary refining element and substantially opposing the stationary refining element such that a refining chamber is formed between opposing refining surfaces of the stationary refining element and the rotatable refining element, the refiner, the refining element, and the refining chamber having an axial direction, a first end, and a second end opposite the first end in the axial direction; In the axial direction of the refining chamber, there is a first refining zone at the first end of the refining chamber for refining a first fiber material fraction and extending toward the second end of the refining chamber, and a second refining zone at the second end of the refining chamber for refining a second fiber material fraction and extending toward the first end of the refining chamber, the second refining zone having at least one different refining surface characteristic with respect to the first refining zone. The refiner of claim 2.

4. the first feed channel is configured to feed the first fraction of fiber material through the first end of the refining chamber into the first refining zone; the second feed channel is configured to feed the second fraction of fiber material through the second end of the refining chamber into the second refining zone; The stationary refining element includes at least one opening in each refining zone, allowing the fibrous material being refined in each of the refining zones to be discharged from the refining chamber through the respective at least one opening. The refiner of claim 3.

5. the first feed channel is configured to feed the first fraction of fibrous material into an interior volume of the rotatable refining element through the first end of the rotatable refining element; the second feed channel is configured to feed the second fraction of fibrous material into an interior volume of the rotatable refining element through the second end of the rotatable refining element; the rotatable element includes at least one opening in each refining zone, allowing the fiber material fraction to be refined in the respective refining zone to be fed into the refining chamber in the respective refining zone through the respective at least one opening; The stationary refining element includes at least one opening in each refining zone, allowing the fiber material fraction to be refined in the respective refining zone to be discharged from the refining chamber in the respective refining zone through the respective at least one opening. The refiner of claim 3.

6. The refiner includes a first stationary refining element, a rotatable refining element within the first stationary refining element and substantially opposing the first stationary refining element such that a first refining chamber forming a first refining zone is formed between opposing refining surfaces of the first stationary refining element and the rotatable refining element, and a second stationary refining element within the rotatable refining element and substantially opposing the rotatable refining element such that a second refining chamber forming a second refining zone is formed between opposing refining surfaces of the rotatable refining element and the second stationary refining element, wherein at least one refining surface characteristic in the second refining zone is different from the respective at least one refining surface characteristic in the first refining zone, The refiner, the refining element, and the refining chamber have an axial direction, a first end, and a second end opposite the first end in the axial direction; the first feed channel is configured to feed the first fiber material fraction into the first refining chamber through at least one end of the first refining chamber; the second feed channel is configured to feed the second fiber material fraction into the second refining chamber through at least one end of the second refining chamber; The refiner of claim 2.

7. The refiner is a first stationary disk-shaped refining element; and a rotatable disk-shaped refining element adjacent to and substantially facing the first stationary disk-shaped refining element such that a first refining chamber defining a first refining zone is formed between opposing refining surfaces of the first stationary disk-shaped refining element and the rotatable refining element; a second, disk-shaped, stationary refining element adjacent to the rotatable refining element on an opposite side of the rotatable refining element relative to the first stationary refining element, the second stationary refining element substantially opposing the rotatable refining element such that a second refining chamber defining a second refining zone is formed between opposing refining surfaces of the rotatable refining element and the second stationary refining element; At least one refining surface characteristic in the second refining zone is different from the respective at least one refining surface characteristic in the first refining zone; the first feed channel is configured to feed the first fraction of fiber material into the first refining chamber, and the second feed channel is configured to feed the second fraction of fiber material into the second refining chamber. The refiner of claim 2.

8. The refiner is a first discharge channel for discharging the first fraction of fibrous material refined in the first refining zone from the refiner; a second discharge channel for discharging the second fraction of fibrous material refined in the second refining zone from the refiner. The refiner of claim 2.

9. The refined surface characteristics include the width of the blade bar and the width of the blade groove.

3. The refiner of claim 2, comprising at least one of a blade bar angle, a blade bar height, a blade groove depth, an opening shape, and an opening size.

10. 1. A method for refining fibrous material containing lignocellulose using a refiner including at least two substantially oppositely positioned refining elements, comprising: feeding at least two streams of at least one fibrous material fraction to be refined into said refiner; exposing the at least two streams of the at least one fibrous material fraction to different refining effects in the refiner; and discharging the streams of fractions of fibrous material exposed to different refining effects from the refiner as separate streams; the refiner is a conical refiner comprising a conical refining element having a first end with a smaller diameter and a second end with a larger diameter; method.

11. The refiner includes a stationary refining element and a rotatable refining element within the stationary refining element and substantially opposing the stationary refining element such that a refining chamber is formed between opposing refining surfaces of the stationary refining element and the rotatable refining element, the refiner, the refining element, and the refining chamber having an axial direction, a first end, and a second end opposite the first end in the axial direction; In the axial direction of the refining chamber, there is a first refining zone at the first end of the refining chamber for refining a first fiber material fraction and extending toward the second end of the refining chamber, and a second refining zone at the second end of the refining chamber for refining a second fiber material fraction and extending toward the first end of the refining chamber, the second refining zone having at least one different refining surface characteristic with respect to the first refining zone, whereby A first fiber material fraction to be refined is fed into said first refining zone; A second fiber material fraction to be refined is fed into said second refining zone; The first fiber material fraction refined in the first refining zone is discharged from the refining chamber in the first refining zone through at least one opening disposed in the stationary refining element in the first refining zone; The second fiber material fraction refined in the second refining zone is discharged from the refining chamber in the second refining zone through at least one opening disposed in the stationary refining element in the second refining zone. The method of claim 10.

12. The first fiber material fraction to be refined is fed into an interior volume of the rotatable refining element through the first end of the rotatable refining element and into the refining chamber at the first refining zone through at least one opening disposed in the rotatable refining element at the first refining zone; the second fiber material fraction to be refined is fed into an interior volume of the rotatable refining element through the second end of the rotatable refining element and into the refining chamber at the second refining zone through at least one opening disposed in the rotatable refining element at the second refining zone; The method of claim 11.

13. 13. The method of claim 11 or 12, wherein the second fiber material fraction is qualitatively different from the first fiber material fraction.

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