SE537048C2

SE537048C2 - Apparatus for producing fibrous pulp of lignocellulosic material

Info

Publication number: SE537048C2
Application number: SE1250207A
Authority: SE
Inventors: Rjan Ahlgren
Original assignee: Valmet Oy
Priority date: 2012-03-05
Filing date: 2012-03-05
Publication date: 2014-12-16
Also published as: EP2823098A1; CN104145059B; SE1250207A1; EP2823098A4; CN104145059A; EP2823098B1; WO2013133750A1

Abstract

ABSTRACT The invention is related to an apparatus for manufacturing fibre pulp fromIignocellulose-containing material, comprising a housing (2) enclosing tworefining disks (3, 4) having opposing refining elements (6, 7), which refiningelements (6, 7) between themselves form at least one refining gap (8), in whichrefining gap (8) the Iingocellulose-containing material is arranged to bedisintegrated into fibre pulp, wherein at least one refining disk (4) is arrangedon a rotary shaft (5) and is rotary in a direction of rotation (R) and having a rearside (11) away from the refining gap (8), so that a space (10) is createdbetween the rear side (1 1) of the rotary refining disk (4) and the housing (2),which rear side (11) is provided with a centre (14), a circumference (17) and atleast one wing member (12, 12a, 12b, 12c) arranged to prevent pulp fromsticking on the rear side (11). According to the invention, the rotary refiningdisk (4) has at least one thought radial line (13) on its rear side (11)extendingfrom the centre (14) to the circumference (17) and in that at least one wingmember (12, 12a, 12b, 12c) is attached to the rear side (11) at an (d, oi1, d2,oi3) from the at least one thought radial line (13) and towards the direction of rotation (R).

Description

APPARATUS FOR MANUFACTURING FIBRE PULP FROMLIGNOCELLULOSE-CONTAINING MATERIAL TECHNICAL FIELDThe invention is related to an apparatus for manufacturing fibre pulp from Iignocellulose-containing material, according to the preamble of claim 1.BACKGROUND A disk refiner or grinder comprises a housing enclosing two opposed refiningdisks, at least one of which is rotary. The refining disks each have refiningelements, between which a refining gap is formed for disintegratinglignocellulose-containing material, such as chips from soft- or hardwood,bamboo, straw, bagasse or similar into fibre pulp. The pulp leaves the refinervia a space on the rear side of the rotary refining disk. A problem is that thepulp sticks to said rear side of the rotary refining disk and to the housing andalso create forces to the bearings which may destroy them. Build ups of burntfibre bindles or particles may later come loose and create problems furtherdown the line in other processing steps. A common problem is e.g. spots on board. lt is known to have straight wing elements aligned along thought radial lines onthe rear side of the rotary refining disks to prevent pulp to stick to the rear sideand/or the housing. A problem with them is that they are not efficient enough.

Further, they have a tendency to create turbulence, which creates wear.SUMMARY An object of the invention is to solve the problems with an invention as in claim1.

By placing the wing members in a positive angle from a thought radial line andtowards a direction of rotation, a better cleaning and less wear of the rear side of the rotary refining disk is obtained. Further, energy can be saved since the direction of the transportation of the particles will be more directed towards the circumference of the refining disk, where an outlet preferably is located. _ Other advantages may be obtained by the different embodiments in the dependent claims.BRIEF DESCRIPTION OF THE DRAWINGS The invention, together with further objects and advantages thereof, may bestbe understood by reference to the following description and appended drawings, in which: Fig. 1 is a schematic cross-sectional view illustrating an apparatus according to an exemplifying embodiment of the invention.

Fig. 2 is a schematic front view illustrating the apparatus in Fig. 1 according to an exemplifying embodiment of the invention.

Fig. 3 is a schematic front view illustrating the apparatus in Fig. 1 according to another exemplifying embodiment of the invention.

Figs. 4a-e are schematic views illustrating the apparatus in Fig. 1 according to further exemplifying embodiments of the invention.DETAILED DESCRIPTION ln Fig. 1 and 2 a refiner 1 according to the invention is disclosed, which is anexample of an apparatus 1 for manufacturing fibre pulp from lignocellulose-containing material. The refiner1 comprises a housing 2 enclosing a stationaryrefining disk 3, also called stator, and a rotary refining disk 4, also called rotor.The stationary refining disk 3 may be connected to the housing 2. The rotaryrefining disk 4 is driven by a motor (not shown) through a rotary shaft 5 andpreferably rotates with 1500-2300 rpm. lt is also possible to have two rotatingrefining disks 3, 4. The refining disks 3, 4 are provided on their surfaces facing towards each other with refining elements 6, 7, which between themselves define a refining gap 8, which preferably is 0.1-2 mm.

The stationary refining disk 3 has an inlet 9, through which material to berefined is fed into the gap 8. lt is preferable to preheat the material with e.g.steam before feeding into the refiner 1 and to refine under pressure in therefiner 1. lt is also possible to have chemical treatment of the material before feeding into the refiner 1. ln the gap 8, the material is preferably first crushed into thin sticks, which bythe centrifugal force are fed outwards to a grinding zone, where the fibres areuncovered and worked so that they become soft and so that the surfaces of the fibres get a good binding capability.

A space 10 is provided between the housing 2 and a rear side 11 of the rotaryrefining disk 4. The material processed in the refiner1 is collected in the space 10 and leaves the refiner 1 through an outlet 18.

The rear side 11 of the rotary refining disk 4 is provided with a centre 14 and acircumference 17. At least one thought radial line 13 extends at least from the centre 14 to the circumference 17.

To prevent the processed material from sticking to the rear side 11 ofthe rotaryrefining disk 4 and to the housing 2, the rear side 11 is also provided with atleast one wing member 12. The wing members 12 can be part of the rotaryrefining disk 4 by e.g. making larger or smaller cutouts in the rear side 11between where the wings members 12 are going to be. However, the wingmembers 12 are preferable separate from, but attached to the rotary refinerdisk 4, because then the wing member 12 can easily be replaced when wornand may also be made from a different material than the rotary refining disk 4,preferably harder. Harder material is often more expensive and since the wingmember 12 is a wear part, then the area of the wing members 12 is preferablysmaller than the area between the wing members 12. Further, the manufacture of the refiner 1 is simplified if the wing members 12 are separate from the rotary refiner disk 4, instead of having to make cutouts in the rotary refiningdisk 12. lnstead of placing all the wing members 12 straight radially aligned, at leastone wing member 12 is at a positive angle d, d1, d2, d3 larger than zero, e.g.around 45°, from a thought radial line 13, towards the direction of rotation R.Different wing members may be at an angle d, d1, d2, d3 to different thoughtradial lines 13. The wing members 12 are preferably placed in a pattern thatpoints in a direction opposite to the direction of rotation R. A pattern is definedas one set of wing members 12 that are arranged between the rotary shaft 5and the circumference 17. A pattern may then be repeated symmetricallyaround the rotary shaft 5.Since the wing members 12 are at an angle d, d1, d2,d3 with a thought radial line 13, the wing members 12 work better than if theyhad been placed straight radially aligned, since the material is thrown out moreefficiently from the centre 14 of the rotary refining disk 4. This gives bettercleaning and less wear. Further, energy can be saved since the direction ofthetransportation of the material will be more directed towards the circumference 17 of the rotary refining disk 4, where the outlet 18 preferably is located. ln Fig. 2, all wing members 12 are at the same angle d from the thought radiallines 13. However, preferably, as in Fig. 3, the wing members 12c furtherfromthe centre 14 of the rotary refining disk 4 are arranged at a smaller angle d3(which in this case may be as small as 0°), than the wing members 12b, 12acloser to the centre 14 of the rotary refining disk 4, which wing members 12b,12a are placed at increasingly larger angles d2, d1. This is because therotation speed of the material is lower closer to the centre 14 and thus a larger angle is preferred.

Small, straight, separate wing members 12, 12a, 12b, 12c as in Fig. 2 and 3are most economical, since they are cheapest to manufacture and you onlyneed to replace the wing members 12, 12a, 12b, 12c that are most worn and therefore not necessarily all at the same time. A stronger attachment may, however, be gained if the wing members 12 are provided with a collar 15,which fits in a corresponding notch 16 in the rear side of the rotary refining disk4. ln Fig. 4a-c is shown schematically other alternatives of wing members 12where the wing members 12 go more or less the whole way from the rotaryshaft 5 to the periphery 17 of the rotary refining disk 4. The wing members 12may be straight or curved and may have equal or varying width. There may beone wing member 12 going all the way from the rotary shaft 5 to the periphery17 of the rotary refining disk 4 as in Fig. 4a and 4b. Or else there may be anumber of separate wing members 12 arranged from the rotary shaft 5 to theperiphery 17, either spaced apart as in Fig. 2, 3, 4d and 4e or overlapping as inFig. 4c. For stability the wing members 23 are preferably arranged symmetricalwith respect to the rotary shaft 5. The figures show 2-4 patterns, but more are possible.

The invention is of course not restricted to the shown embodiments, but may be varied within the scope of the claims.

Claims

1. Apparatus for manufacturing fibre pulp from Iignocellulose-containing material, comprising a housing (2) enclosing two refining disks (3, 4)having opposing refining elements (6, 7), which refining elements (6, 7)between themselves form at least one refining gap (8), in which refining gap (8)the Iingocellulose-containing material is arranged to be disintegrated into fibrepulp, wherein at least one refining disk (4) is arranged on a rotary shaft (5) andis rotary in a direction of rotation (R) and having a rear side (1 1 ) away from therefining gap (8), so that a space (10) is created between the rear side (11) ofthe rotary refining disk (4) and the housing (2), which rear side (11) is providedwith a centre (14), a circumference (17) and at least one wing member (12,12a, 12b, 12c) arranged to prevent pulp from sticking on the rear side (11),characterised in that the rotary refining disk (4) has at least one thoughtradial line (13) on its rear side (11) extending from the centre (14) to thecircumference (17) and in that at least one wing member(12, 12a, 12b, 12c) isattached to the rear side (11) at a positive angle (d, d1, d2, oi3) from the at least one thought radial line (13) and towards the direction of rotation (R).

2. Apparatus according to claim 1, characterised in that the at least one wing member (12, 12a, 12b, 12c) is integrated into the rotary refining disk (4)-

3. Apparatus according to claim 1, characterised in that the at leastone wing member (12, 12a, 12b, 12c) is separated from and attached to the rotary refining disk (4).

4. Apparatus according to any of the claims 1-3, characterised in thata wing member (12a, 12b) further from the centre (1 4) of the rotary refining disk(4) is at a smaller angle (oi1, 0:2) from the at least one thought radial line (13)than a wing member (12b, 12c) closer to the centre (14) of the rotary refiningdisk (4).

5. Apparatus according to any of the claims 1-3, characterised in thatall wing members (12, 12a, 12b, 12c) are at the same angle (oi, oi1, oi2, oi3) from the at least one thought radial line (13).

6. Apparatus according to any of the claims 1-5, characterised in thatthe at least one wing member (12, 12a, 12b, 12c) is of a harder material than the rotary refining disk (4).

7. Apparatus according to any of the claims 1-6, characterised in thatthe at least one wing member (12, 12a, 12b, 12c) is provided almost all the way from the rotary shaft (5) to the circumference (1 7) of the rotary refining disk (4).

8. Apparatus according to any of the claims 1-6, characterised in thatmore than one separate wing member (12, 12a, 12b, 12c) are providedbetween the rotary shaft (5) and the circumference (17) of the rotary refiningdisk (4).

9. Apparatus according to any of the claims 1-8, characterised in thatthe rotary refining disk (4) is provided with notches (16) and in that the wingmembers (12, 12a, 12b, 12c) are provided with collars (15) fitting in thenotches (16).

10. Apparatus according to any of the claims 1-9, characterised in thata pattern is defined as one set of wing members (12) that are arrangedbetween the rotary shaft (5) and the circumference (17), which pattern is repeated symmetrically around the rotary shaft (5).