Title of Invention | REFINING SURFACE AND A BLADE SEGMENT FOR A REFINER. |
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Abstract | A refining surface for a refiner intended for XXX l igooceliulose-conteining natureal The refiining surfes (1, 2) comprised firrt bars 113) contending from tbe inner circumtence of the circumfotence of the refining XXX (1.2) and between than finer grooves (1.3) The oppor surface (18) of the XXX bars (12) further compring first grooves (13) between which second grooves (15) there are second bars (14), which are narrower than the first bars (12). Furtherman, a blude segment for formating refer surfac blades of a refiner untended for defibrning XXX XXX material. |
Full Text | Refining surfacc and a blade segmem for a refiner BACKGROUND OF THE INVENTION [0001] The invention relates to a refining surface for a refiner in- landed tor defibrating lignocellulose-containtng material, the refiner comprising 5 at least two refining surfaces arranged coaxially relative to each other, at least one of which refining surfaces is arranged to rotate around a shaft, and be- tween which refining surfaces the material to be defibrated is fed, and which refining surface comprises first bars extending from the inner circumference of the refining surface to the outer circumterence of the refining surface and be- 10 tween them first grooves, and the upper surfaces of which first bars further comprise second grooves connecting said first grooves, and between which second grooves there are second bars. [0002] The invention further relates to a blade segment for a refiner intended for defibraling lignocellulose-containing material, the refiner compris- 15 ing at least two refining surfaces arranged coaxially relative to each other, at least one of which refining surfaces is arranged to rotate around a shaft, and between which refining surfaces the material to be defibrated is fed, and which blade segment can be arranged to form at least a part of at least one refining surface, and which blade segment comprises first bans extending from the in 20 ner circumference of the refining surface to the outer circumference of the re- fining surface and between them first grooves, and the upper surfaces of which first bars further comprise second grooves connecting said first grooves, and between which second grooves there are second bars, [0003] Disc and cone refiners used for treatment of fibrous material 25 are typically formed of two or possibly more refiner discs opposite to each other which are arranged to turn relative to each other so that at least one of said refiner discs is arranged to rotate around a shaft. In disc refiners the re- finer disc is disc-like and in cone refiners it is conical. In a refiner comprising two refiner discs, one of the refiner discs further comprises an opening through 30 which the material to be refined is fed into the refiner. The part of the refiner disc where said feed opening is located can be called a feed end. The refiner discs are positioned in such a way that they form a retiner gap between them, where llgnocellulose-containing material is defibrated. The distance between the refiner discs is longest on the feed side or at the feed point of the lignocel- 35 lulose-containing material i.e., in a disc refiner, in the middle of the discs, and WO 2005/032720 PCT/FI2004/000589 2 in a cone refiner, at the cone end having a smaller diameter, said gap being reduced towards the discharge point or discharge side of the material to be refined in order to gradually grind the material to be refined. [0004] The refining surfaces of refiner discs are typically formed of 5 protrusions. i.e. blada bars, extending from the inner circuinference of the re flhing surface to the outer circumference of the refining surface, and of grooves between the blade bars- Hereafter, blade bars are also called bsrs. The shape of these grooves end bars per se may vary in different ways. Thus, for exam ple, in the radial direction of the refiner disc the refining surface may be divided 10 into two or more circular parts, each circumference having bars and grooves whose number and density as well as their shape and direction may deviate from each other. Thus, the bars may be either continuous over the whole length of the refining surface radius or there may be a plurality of separate, successive bars in the radial direction. At the refiner rotor, the bars and the 15 direction thereof have a greater effect than at the stator because of the rotation of the rotor, whereby the fibrous material to be refined is subjected especially by the rotor bars to a refining force resultant which affects with a velocity de- termined on the basis of the radius and rotational speed of the refining surface. The bars of the stator form counter pairs or a counter surface for the rotor, re- 20 quired in refining, the blade bars crossing each other during refining like scis- sor blades. However, there is a small clearance between the rotor bars and stator bars of the refiner, and the fibrous material is mainly ground or refined between them. [0005] Refining surfaces of refiner discs can be formed directly onto 25 the surface of the refining discs for example by casting or by separate machin ing but usually a refining surface is formed of blade segments which are ar ranged next to each other on the refiner disc both in the radial and in the circu- lar direction of the refiner disc so that the refiner disc is provided with 3 uniform refining surface. Thus, each blade segment forms a part of the refining surface 30 of the refiner disc. [0006] In the case of a disc refiner, the inner circumference of the refining surface refers to the middle part of the refining surface and, in the case of a cone refiner, to the end of said cone with the smaller diameter. The outer circumference of the refinmg surface naturally refers, in the case of a disc re- 35 finer, to the outer part of the refining surface, i.e. the part where the circumfer- WO 2005/032720 PCT/FI2004/000589 4 surface of which is provided with small grooves at sparse intervals, which can slightly increase the flow capacity of the grooves between the bare and facili tate the discharge of steam produced during refining from between the refining surfaces- Said grooves on the upper surface of the blade bar also add to the 5 combined cutting length of the bars of the refining surface to some extent, but, in practice, the oblique structure of the upper surface of the blade bar hinders these small grooves from participating in the refining of the material before the blade bar has worn significantly, which means that one has not, nevertheless succeeded in substantially increasing the refining capacity of the refiner. 10 BRIEF DESCRIPTION OF THE INVENTION [0010] It Is an object of the present invention to provide a new refin- ing surface or blade solution for a refiner, enabling a higher refining capacity than previously. [0011] The refining surface of the invention is characterized in that 15 the second bars are narrower than the first bars. [0012] Furthermore. the blade segment of the invention is charao terized in that the second bars are narrower than the first bars. [0013] According to the essential idea of the invention, at least one refining surface of a refiner intended for defibrating lignocallulose-containing 20 material comprises first bars extending from the inner circumference of the re- fning surface to the outer circumference of the refining surface and between them first grooves, and the upper surfaces of the first bars further comprise second grooves connecting said first grooves, between which second grooves there are second bars, which are narrower than the first bars. According to an 25 embodiment of the invention, the average width of the first bar is 2.5- to 40-fold in respect of the average, combined width of the second bar and the second groove. According to another embodiment of the invention, the total area of the refining zones of the refining surface formed of the second bars and the sec- and grooves is 60 to 90%, preferably 70 to 80%, of the total area of the refining 30 surface. [0014] With the solution of the invention, a high cutting length can ba achieved on the refining surface. Since the first grooves have a volume that is clearly larger than previously, an optimal, steady feed of the fibrous material to be refined can be achieved over the entire area of the refining surface. The 35 refining surface of the solution can thus provide both the desJnsd capacity and WO 2005/032720 PCT/FI2004/000589 5 a good quality of the refined pulp. Unlike before, the same refining surface so- lution can also be applied to the refining of both long and short fibre. BRIEF DESCRIPTION OF THE FIGURES [0015] The invention will now be described in more detail in the af- 5 tached drawings. in which Figure 1 schematically shows a side view of a typical disc refiner in cross-section. Figure 2 schematically shows a side view of a typical cone refiner in cross-section 10 Figure 3 schematically shows a part of a refining surface of a disc refiner, seen in the direction of the refining surface, Figure 4 schematically shows a top view of a first bar of the refining surface according to Figure 3. Figure 5 schematically shows a cross-section of the bar according 15 to Figure 4 along line V-Vof Figure 4, Figure 6 schematically shows a second refining surface of the disc refiner, seen in the direction of the refining surface, Figure 7 schematically shows a third refining surface of the disc re- finer, seen in the direction of the refining surface, 20 Figure 8 schematically shows a part of a refining surface of the rotor of a cone refiner, seen in the direction of the refining surface. Figure 9 schematically shows a part of a refining surface of the sta- for of a cone refiner, seen in the direction of the refining surface, Figure 10 schematically shows a cross-section of the refining sur- 25 face according to Figure 8 along line C - C of Figure 8, Figure 11 schematically shows a cross-section of the refining sur- fice according to Figure 9 along line C — C of Figure 9, Figure 12 schematically shows a detail of the refining surface in crass-section, 30 Figure 13 schematically shows a part of a refining surface of a re- finer, seen in the directon of the refining surface, Figure 14 schematically shows a cross-section of the refining sur- face according to Figure 13. Figures 15a and 15b schematically show two embodiments of the 35 refining surfaces, seen in the direction of the refining surfaces, and WO 2005/032720 PCT/FI2004/000589 7 brous material to be refined and at the outer circumference of the refiner discs 3 and 5 there is the discharge side or discharge point for the refined fibrous material. [0019] Figure 2 shows schematically a side view of a typical cone 5 refiner in cross-section. The cone refiner comprises two conical refining sur- faces 1 and 2, which are positioned within each other coaxlally. In this em- bodiment, the first refining surface 1 is in a rotating conical refiner disc 3, i.e. a rotor, which is rotated by means of the shaft 4. The second refining surface 2 is in a fixed conical refiner disc 5. i.e. a stator. The refining surfaces 1 and 2 of 10 the refiner discs 3 and 5 may be either formed directly onto the discs or formed of separate blade segments in a manner known per se. Further. Figure 2 shows a loader 6 connected to affect the refiner disc 3 via the shaft 4 so that it can be pushed towards the refiner disc 5 to adjust the gap between them. The refiner disc 3 is rotated via the shaft 4 in a manner known per so by means of a 15 motor not shown for the sake of clarity. [0020] The lignocellulose-containing material to be defibrated is fed through an opening 7 in the middle of the second refining surface 2, i.e. from the end of the cone structure having the smaller diameter, into a conical gap between the refining surfaces 1 and 2. i.e. a conical refiner gap, where it is de- 20 fibrated and refined. The material that has been defibrated is discharged through a gap between the refiner discs 3 and 5 from the outer edgs of the refiner gap, i.e. from the end of tne cone structure with the larger diameter, into the refiner chamber 3. from which refiner chamber 8 it is further discharged along the discharge channel 9. At the opening 7 in the middle of the refining 25 surface 2 there is the feed point or feed side for the fibrous material to be re- fined and at the end of the refiner discs 3 and 5 having the larger diameter there is the discharge side or discharge point for the refined fibrous material [0021] Figure 3 shows a part of a refining surface of a disc re- timer intended for refining fibrous material with a high cancentrartion. The refin- 30 ing surface is provided with a pattern of first bars 12 and first grooves 13 be- tween them. Figure 4 shows an embodiment of tha bars 12 of the refining sur- face in Figure 3, and Figure 5 shows a section along line V - V of Figure 4. The first bars 12 have upper surfaces 18 and side surfaces 19 with edges 20. The pattern of bars 12 is divided into two refining surface zones 16, the inner 35 zone 16 and the outer zone 16, whereby the bars 12 and the grooves 13 in the inner zone 16 are mone sparsely distributed than in the outer zone 16. The WO 2005/032720 PCT/FI2004/000589 8 bars 12 in the inner zone 16 are intended for bringing about a first disintegra tion of the material and for advancing the material outward to the outer zone 16'. The bars 12 in the outer zone 16' are placed more closely to each other, which means that there are more oar edges for effecting the substantial work- 5 ing and refining of the material. The pattern of bars 12 can also comprise more zones, whereby the pattern is usually made denser from zone to zone in the radially outward direction. [0022] Figure 4 shows an embodiment where a plurality of smaller grooves or second -grooves 15 are placed along the bars 12, which 10 grooves are arranged slightly angular in relation to the longitudinal direction of the bars 12 and are open to both side surfaces of the bars 12. Due to the bars 12 provided with oblique, smaller second grooves 15 on the upper surfaces 18, the first bars 12 as well as the first grooves 13 between them can be made wider without that the working upper surface of the bars 12 loses its effectlve- 15 ness. By means of the wider first grooves 13. the steam and, respectively, liq- uid flow in the grooves 13 is facilitated and the disturbance of the working of the fibrous material is minimised. [0023] Figure 6 shows another embodiment of the bars 12. Unlike in Figure 4, the bars 12 are arc-shaped. The smaller second grooves 15 20 on the upper surface 18 of the bars 12, however, are always oblique in relation to the longitudinal direction of the bars 12. The seccmd grooves 15 therein should be suitably in the substantially radial direction. [0024] According to Figure 7, the smaller grooves 15 are an- gular in different directions, preferably in such a way that they cross each other 25 on the upper surface of the bare 12. Alternatively, they can be offset in the ion- gitudinal direction of the bars 12 so that they do not cross each other. These embodiments allow that the rotation direction of the refiner discs can be changed. [0025] Figure 8 shows schematically a blade segment 10 forming a 30 part of a refining surface 1 of the rotor of a cone refiner, seen in the direction of the refining surface 1. Figure 9 shows schematically a blade segment 11 form- ing a part of a refining surface 2 of the stator, seen in the direction of the refin- ing surface 2, The refining surfaces 1 and 2 comprise blade bars 12, i,e, bars 12. The bars 12 form first bars of the refining surfaces 1 and 2. Between the 35 bars 12 there are grooves 13 forming first grooves of the refining surfaces 1 and 2. The upper surface of the bars 12 is provided with a dense structure of WO 2005/032720 PCT/FI2004/000589 9 grooves, comprising grooves 15 and bars 14 between them. The bars 14 form second bars of the refining surfaces 1 and 2. The grooves 15 form second grooves of the refining surfaces 1 and 2. The bars 14 and grooves 15 of the refining surface 1 at the rotor are schematically shown in Figure 10, which llus- 5 trates a crass-section of the refining surface 1 along line C - C of Figure 8. The bars 14 and grooves 15 of the refining surface 2 of the stator are schematically shown in Figure 11 illustrating a cross-section of the refining surface 2 along line C- C of Figure 9. [0025) The refining surfaces according to Figures 3 to 11 ara char- 10 acterized in that the refining surfaces comprise first bars 12 and first grooves 13 between the first bars 12. Further, the upper surface 18 of the first bars 12 comprises second bars 14, between which there are second grooves 15. In their direction of travel, the second bars 14 are narrower than the first bars 12, end the second grooves 15 are also in their direction of travel narrower than 15 the first grooves 13, The upper surface of the first bars 12 is thus provided with a dense structure of grooves, i.e. a structure of microgrooves. for refining the llgnocellulose-containing material. The refining surfaces are formed in such a manner that the total area of the microgrooved refining zones formed of the upper surfaces of the bars 12 equals 60 to 90% of the total area of the refining 20 surfaces. The refining surfaces are preferably formed in such a manner that the total area of said microgmoved refining zones is 70 to 80% of the total area of the refining surfaces, [0027] The purpose of the microgrooved refining zones on the up- psr surface of the bars 12 is to refine said lignocellulose-containing fibrous ma- 25 terial. Between the refining surfaces 1 and 2 of the refiner there is a small cearanee, due to which the refining of said fibrous material takes place be- tween the refining surfaces 1 and 2. The purpose of the first grooves 13 is to transport fibrous material to be refined to the refining zones formed of the mi- crogrooved upper surfaces of the bars 12 and to transport the refined material 30 away from between the refining surfaces 1 and 2. In addition, the purpose of the first grooves 13 in high-consistency refining is to tnansport water vapour produced during refining away from between the refining surfaces 1 and 2. [0028] The refining surfaces 1 and 2 can be implemented in various aways. For instance, the first bars 12 and the first grooves 13 between them on 35 the refining surfaces can be farmed in a variety of ways in respect of their size and shape. The bars 12 can be. for instance, 15 to 80 mm. preferably 20 to 40 WO 2005/032720 PCT/FI2004/000589 10 mm, wide. The width of the grooves 13 between the bars 12 can be, for in- stance. 5 to 40 mm, preferably 10 to 30 mm, for example. Both the bars 12 and he grooves 13 can be formed in such a way that their width remains the same or changes according to the direction of travel of the bars or grooves. The 5 depth of the grooves 13 can be 10 to 40 mm. for example. The grooves 13 can be formed in such a way that the depth thereof remsvns the same or changes in the direction of travel of the grooves. It can be said that as the width and/or depth of the groove 13 changes, We cross-sectional area of the groove 13 or he volume of the groove 13 changes. Thus, the cross-sectional flow area of 10 the grooves 13 can vary between 0.5 and 16 cm2, [0029] As to the shape of the bars 12, they can either either di rectly in the radial direction of the refining surface from the shaft of the refining surface to the outer circumference of the refining surface or the bars 12 can be curved at a standard or a varying angle from the shaft of the refining surface to 15 the outer circumference of the refining surface, whereby the edges of the bars 12 can be curved uniformly or they may have steps. The shape of the bars 12 naturally determines the shape of the grooves 13 between the bars 12. Fur- ther, the bars 12 can be formed in such a way that they are pumping at the feed end of the fibrous material to be refined and retentive or non-pumping at 20 the discharge end of the refined fibrous material, which is why it is possible to compensate for a low pumping centrifugal force on the feed side and a high pumping centrifugal force, on the discharge side. An example of this is shown in Figure 23 wherein the first bars 12 are pumping at the feed end and non- pumping at the discharge end. in this example the second bars 12 are pump- 25 ing throughout the biade segment according to Figure 23. The attachment points of the blade segment are denoted with reference numeral 21. [0030] A pumping blade bar means that when the refiner rotor ro tates in the pumping direction, the blade bar produces for the mass particle both a circular vetocity component and a radial velocity component directed 30 away from the centre, whereby the mass particle tends to move away from between the refiner discs, A retentive blade bar, for its part, means that when the refiner rotor rotates in the retentive direction, the blade bar produces for the mass particle both a circular velocity component and a radial velocity compo- rent directed towards the centre, whereby the mass particle tends to remain 35 between the refiner discs. WO 2005/032720 PCT/FI2004/000589 11 [0031] The width of the second grooves formed on the upper sur face of the first bars 12 can be 1 to 3 mm, for instance. Also the width of the second bars 14 which remain between the second grooves 15 can be 1 to 3 mm, for example. The average width of the first bars 12 is thus about 2.5- to 5 40-fold in respect of the combined average width of the second bars 14 and the second grooves 15. The bars 14 and the grooves 15 may have s constant width in their direction of travel but said width of the bars 14 and the grooves 15 can also change in their direction of travel. Said second bars 14 and sec- ond grooves 15 are thus positioned as densely as possible on the upper sur- 10 face of the first bars 12 so that the cutting length of the refining zones of the refining surfaces 1 and 2 becomes as great as possible. [0032] The bars 14 and the grooves 15 can be formed on the upper surface of the bars 12 in such a manner that they forms an angle of about 5 to 30° to the radlus of the refining surface in one direction or another. The bars 15 14 can be formed such that with a specific radius, the angle of attack of the bars 14 on the opposing refining surfaces is constent over the antire area of the refining surface. The grooves 15 can be formed such mat they can be ol- ther pumping or retentive. When the grooves 15 are pumping, the pulp is taken more effectively towards the discharge, thus achieving a uniform refining re- 20 sult. If the grooves 15 are retentive, the refining result is not so uniform but, on the other hand, the residence time distribution of the fibrous material is greater. Thus, to achieve a uniform refining result, refining surfaces are used, the sec- ond grooves 15 of which are pumping. If it is more important to achieve a long reining treatment of fibrous material than a uniform refining result, refining sur- 25 faces are used, the grooves 15 of which are retentive. The grooves 15 can also be implemented in such a manner that the purpose thereof is not to affect the time the material to be refined remains between the refining surfaces. [0033] The second grooves 15 on the upper surface of the bars 12 can be, for instance, 3 to 5 mm deep. Thus, the first grooves 13 are at least 30 twice as deep as the second grooves 15. In practice, the greatest groove depth of the grooves 15 is determined by the thickness of the wear surface of the refining surfaces. The depth of the groove 15 can either be constant or vary in the direction of travel of the groove 15. The depth of the groove 15 can also vary in the width direction of the groove 15 so that, for instance, the groove 15 35 is deeper on the front side than on the back side, which produces a lifting force and the blade does not cut through the fibre matting nor break the fibres. The WO 2005/032720 PCT/FI2004/000589 12 front side refers to the front edge of the groove 15 and the back side to the back edge of the groove 15, when seen in the rotation direction of the refiner disc. This solution is shown schematically in Figure 12, which Illustrates a first bar 12 in cross-section. Such a solution can be advantageous when the aim is 5 to achieve a high load capacity for the postrefining of mechanical pulp or for short-fibred pulp. In the refining of long-fibred pulp, the grooves 15 can have an equal depth or they can even be deeper on the back side of the groove then on its front side. [0034] The refining surface according to the solution makes it pos- 10 sible trtat in the refining, a very small load on the bar can be used without irn- pairing the hydraulic capacity of the refiner. Usually when long-fibred pulp is lefined with short-fibre blades intended for refining short fibres, a sufficient hy- draulic capacity is not achieved and the Dlades of the refiner are blocked. On the refining surface according to the solution, grooves 13 with a clearly larger 15 volume than previously enable an optimal, constant feed of the fibrous material is be refined in the entire area of the refining surface. Due to the bars 14 and grooves 15 on the upper surface of the bars 12 and forming the refining zones of the refining surfaces 1 and 2 and providing a clearly denser structure of bars and grooves than the previously known solutions, a high cutting length can be 20 achieved on the refining surface. The refining surface of the solution can thus provide a desired capacity and a good quality of the refined pulp. In addition, unlike previously, the same refining surface solution can be applied to the re fining of both long and short fibre. Further, with a specific energy consumption which is 10 to 20% lower than before, the refining surface of the solution pro- 25 vides the same quality or strength change as previously. Furthermore, by using the same cutting length as before, the refiner can be used with a load that is 20% greater without any blade contact Also, a greater power can be used without decreasing the fibre length of short fibre, which means that short-fibre refining can be carried out by using fewer refiners. 30 [0035] Figures 19 to 22 show test run results achieved with both a conventional refining surface and the refining surface according to the solution. Figure 19 shows a situation in which long fibre is refined with the conventional refininig surface (broken line) and with the refining surface according to the so- lution (continuous line). The purpose was to increase the refining degree, i.e. 35 fineness of pulp from the value of CSF 700 ml to tte value ot CSF 300 ml. It appears from Figure 19 that, in the case of the conventional refining surface. WO 2005/032720 PCT/FI2004/000589 13 185 Kwhtton of energy was needed to increase said refining degree, whereas the energy demand in the case of the refining surface of the solution was only 140 kwh/ton which corresponds to an energy saving of 25%. Figure 20, in urn, shows that the bonding strength (Scott Bond) of pulp developed clearly 5 faster when the refining surface of the solution was used. In the case of the refining surface of the solution (continuous line), 120 kWh/ton of energy was needed to achieve the bonding strength of 400 J/m2, whereas the energy da- mand of the conventional refining surface was 150 kWh/ton. Thus, particularly when long fibre is refined, the refining surface of the solution provides consid- 10 arable energy savings in comparison with the conventional refining surface. [0036] Figure 21 shows a situation where short fibre is refined with the conventional refining surface (broken line) and with the refining surface according to the solution (continuous line). The purpose was to increase the tensile index of the fibre from the starting value of 41 kNm/g. On the basis, of 15 the test run, it was not reasonable to load the conventional refining surface more than 80 kWh/ton, because, after this, the tensile index started to become lower. In this case, the tensile index of a specimen made of the test run pulp was 67 kNm/g. At the same time as the tensile index started to become lower, me distance between the refining surfaces of the refiner became shorter, which 20 caused a risk of a harmful contact between the opposing refining surfaces. The refining surface of the solution did not have this problem, wherefore higher tensile indexes were achieved and the load capacity of the refiner was main- teined until the end and the test produced a tensile index of 73 kNm/g with a refining energy of 120 kWh/ton. 25 [0037] Figure 22 shows how the fibre length changes, in the case of the refining surface of the solution (continuous line) and in the case of the con- ventional refining surface (broken line). Although there was no essential differ- ence between the cutting lengths of the conventional refining surface and the refining surface of the solution, the conventional refining surface out fibre, 30 whereas the fibre length did not essentially decrease by using the refining sur- face of the solution. With an energy consumption of 120 kWh/ton in the refin- ing, the fibre length decreased from 0.87 mm to 0.78 mm when the refining surface of the solution was used, whereas in the case of the conventional refin- ing surface, the fibre length decreased to 0.66 mm and a contact occurred be- 35 tween the refining surfaces. Particularly in the refining of short fibre, the rerfin- ing surface of the solution provides, above all, toe advantage of a higher load WO 2005/032720 PCT/FI2004/000589 14 capacity of the refiner since, conventionally, if the refiner is loaded too much, the refining surfaces will have a harmful contact. Thus, more energy can be consumed par each mass ton, without decreasing the fibre length substantially or having a contact between the refiner surfaces. The refining surface of the 5 solution is thus particularly suitable tor fibres which are sensitive ta overload and to a refiner surface contact. Examples of such situations include postrefin- ng of mechanical pulp and short-fibred mechanical pulp and refining of chemi- cal pulp and recycled fibre pulp. [0038] Bars with a design presented above can be placed in any 10 zone on the refining surface, but preferably at least in the outer zone where the working and refining are most intensive and the distance between the oppos- ing refining surfaces is the shortest, ie. the refining gap is the smallest and possible steam development the greatest. During the working of fibrous mate- rial with the refining surfaces presented above, the upper surfaces of the bars 15 12 and the edges of the smaller second grooves will work on the material. The steem the development of which arises in the case of a higt concentration re- fining and the liquid flow that passes through the refining gap in the case of a low concentration refining are led away from the upper surfaces of the bars 12 and can pass out through the grooves 13 between the bars 12 so that the 20 working of the fibrous material is not disturbed, In this way, a high capacity can be achieved and the pulp quality maintained. By providing the refining surfaces with are-shaped first bars 12 with substantially radial, smaller second grooves 15 on the upper surface, an increased capacity can be obtained and, at the same time, a high pulp quality achieved so that the smaller second grooves 15 25 bring about an effective fibrillation of the fibrous material. [0039] Figure 13 shows schematically a part of a refining surface, seen in the director of the mining surface, and Figure 14 shows schematically the refining surface according to Figure 13 in cross-section in the longitudinal direction of the groove 13. In the refining surface according to Figures 13 and 30 14, the number of the second bars 14 increases from zone to zone from the feed side of the refinfng surface to the discharge side of the refining surface. Thus, seen from the feed end of the refiner, the first refining surface zone comprises the lowest number of second bars 14 and the last refining surface zone the highest number of second bars 14. This can be implemented, for in- 35 stance, so that in the first refining surface zone seen from the feed end. the with of the second grooves 15 between the second bars 14 corresponds to WO 2005/032720 PCT/FI2004/000589 15 the maximum value of the variation range of the groove width presented above, and in the last refining surface zone, the width of said grooves 16 cor- responds to the minimum value of the variation range of said groove width, The refining surface zones are denoted In Figure 13 with reference numeral 5 16. Of course, as seen from Figure 13, the second grooves 15 between the second bars 14 can also be essentially wider at the feed end than at the dis- change and. [0040] Figure 14 also shows how the depth of the sceond groove 15 changes so that the depth of the groove 15 at the end of each refining surface 10 zone is smaller than at the beginning of the next refining surface zone. Hence, the grooves 15 become lower step by step towards the discharge side. This leads to a half-dam, which physically hinders return flows of the refined mate- rial. The grooves 15 could also be implemented in such a way thai they be- come steadlly lower towards the discharge side. The depth of the second 15 gooves 15 on the upper surface of the first bars 12 and the depth of the first gooves 13 are dimensioned, for instance, so that the maximum values of the variation ranges of the groove depths mentioned above are used on the feed side and the minimum values of the variation range of said groove depths are used on the discharge side. 20 [0041] The embodiment according to Figures 13 and 14 is charac- terized in that the cross-sectional flow area of the refining surface remains the same or becomes smaller towards the discharge of the material to be refined, whereby the flow rate of the fibrous material to be refined remains the same or becomes higher towards the discharge. A stepwise denser structure of the re- 25 fining surface decreases the cross-sectional flow area, whereby the smaller cross-sectional flow area is compensated for by making the grooves deeper. On the other hand, as the number of grooves increases in the direction of the outer circumference of the refining surface, the bigger cross-sectional flow area is compensated for by lower grooves. This provides even flow of the re- 30 fined material and fibre treatment in which the return flows of the refined mate- rial can be minimised and the residence time distribution decreased so that all fibres are provided with as uniform treatment as possible. A uniform fibre treatment is advantageous in applications where a high strength and density of paper is required without decreasing the paper porosity. Also the smoothness 35 and quality of the paper surface improve as the number of unrefined fibres de- creases. In addition. it is easier to control the pressure rise between the refiner WO 2005/032720 PCT/FI2004/000589 16 discs, as a result of which the refiner runs more smoothly and does not have so much vibrations and has a no-load operation power that is about 20 to 30% smaller than before, [0042] Figures 15a and 15b show a part of a refining surface, seen 5 in the direction of the rafining surface, and Figures 16a and 16b show the refin- ing surface according to Figures 15a and 15b in cross-section. For the sake of clarity. In the embodiment according to Figures 15a, 15b. 16a and 16b, one or more foils 17 are provided on the refining surface 1 of the rotor plate 3 of the refiner. for example, by casting. The foil 17 fs placed onto the bottom of the 10 first groove 13. [0043] The foils 17 are placed onto the refining surface of the rotor slate 3 such that when the rotor rotates in the pumping direction, the foils 17 produce a lifting force. At the same time, a power is produced in the stator, restricting the pumping effect of the bars 12 and simultaneously causing an 15 effective mixing of the fibres and water, which prevents the refining surfaces from being blocked. In addition, due to the suction effect caused by the foils 17, the grooves of the refining surface of the stator are cleaned. When such a rotor provided with foils 17 rotates in the non-pumping direction, the foil 17 acts as a pumping part causing a push force, which intensifies the pumping effect 20 and improves the passing through of the fibre materials. The push force of the foil 17 causes a pressure pulse, which pushes the pulp through the refiner. Due to the solution, the refiner throughput difference between the pumping and non-pumping directions of the rotor becomes smaller. [0044] The foil can be continuous and be located on the blade sur- 25 face either radially or in a curved manner. A radial foil provides a stronger pulse than a curved one. The foil can also consist of bits. The foli bits can also be randomly placed on the refining surface. Typically, the foil has a length of 30 to 80 mm, preferably 50 to 60 mm, the length being defined in the trans- verse direction to the first groove. The depth of the foil can be, for instance, 30 about 20 mm, and the shortest distance of the foil from the counter surface is. or instance, 3 nrcm in the beginning. As the refining surfaces wear, the distance becomes shorter and the power of the suction pulse becomes higher. The fre- quency of the desired suction pulses can be controlled by changing the nurn- oer of foils on the refining surface. 35 [0045] Foils and a gradually denser structure of bars and grooves as well as either a stepwise or a regular change in the groove depth can natu- WO 2005/032720 PCT/FI2004/000589 17 rally also be utilised as such in other refining surface solutions than in the refin- ing surfaces provided with both the first bars 12 and first gloves 13 and the second bare 14 and second grooves 15. Thus, these features can be utilized, for example, in the refining surfaces according to Figures 1 and 3 of the US- 5 publication 4 676440 or in the refining surface according to Figure 17. Figure 17 shows schematically a refining surface, which only comprises second grooves 15 and second bars 14 arranged densely with respect to each other and which are known as microgrooves and micro bars. The refining surface of Figure 17 is a highly preferred solution, as a refining surface of the stator the 10 refining surface of the rotor being in accordance with the above description, The refining surface of Figure 17 can especialty be used as a counter surface or the refining surfaces shown in Figures 13 to 16. A counter surface can naturally also be any previously known refining surface solution. [0046] Figure 18 shows schematically a refining surface according 15 to the solution being used in a double disc (DD) refiner. In the middle of Figure 18 there are two rotor plates attached to each other on their backsides and one refiner stator plate on each side of the rotor plates. Refining surfaces of said rotor plates are normally mirror images of each other and so are the two Stator plates, i.e, if one of the two slots of the refiner function pumping then so 20 does the other one, too, by means of which the functioning of the two-slot re- finer of Figure 18 is ensured, i.e. the gaps between the plates of ihe slots can be kept under control. The two-slot refiner can be changed from pumping to non-pumping by changing both rotor plates and stator plates among each other. By doing so the refiner is changed from pumping to non-pumping with- 25 put changing the rotation direction of the refiner. The two-slot refiner can be changed from pumping to non-pumping also by changing the rotation direction of the rotor. Further one possibility to change from pumping to non-pumping is to change only the rotor plates among each other. The case demands that sta- for plate design differs adequately from rotor piates because also after the 30 change there have to be certain difference between blade bar angles of oppo- site refiner plates to avoid clashing of the plates. All the technical features pre- sented also in Figures 13 to 17 can naturally be used with double disc refiners. Similarly all the technical advantages of the refining surface according to the solution are naturally present also in double disc refiners. 35 [0047] The drawings and the related description are only intended for Illustrating the idea of the invention. In its details, the invention may vary WO 2005/032720 PCT/FI2004/000589 18 within the scope of the claims. The examples of the figures describe different embodimenls associated with refining surfaces of the stator amd rotor of either a disc refiner or a cone refiner, but it is naturally obvious that what is explained about the structure of the refining surfaces of the rotor and stator of a cone 5 refiner can also be applied, to this appropriate extent, to the structures of the refining surfaces of the stator and rotor of 3 disc refiner, and vies versa. PCT/FI 2004 /000589 19 CLAIMS (Amended on 3 May 2005) 1. A refining surface for 3 refiner intended for defibrating lignocellu- to se-cantaining material, the refiner comprising at least two refining surfaces (1 2) arranged coaxially relative to each other, at least ona of which refining 5 surfaces (1,2) is arranged to rotate around a shaft (4), and between which re- firifng surfaces (1, 2) the material to be defibrated is fed, and which refining surface (1,2) comprises first bars (12) extending from the inner circumference of the refining surface (1, 2) to the outer circumference of the refining surface (1 2) and between them first grooves (13). and the upper surfaces (18) of 10 which first bars (12) further comprise second grooves (15) connecting sald first grooves (13), and between which second grooves (15) there are second bars (14) characterized in that the second bars (14) are narrower than the first bars (12) and the 15 width of the second bars (14) is 1 to 3 mm. 2. A refining surface as claimed in dairn 1, characterized in that the average width of the first bar (12) is 2.5- to 40-fold in respect of the combined, average width of the second bar (14) and the second groove (15), 3. A refining surface as ciairmed in claim 1 or 2, character 20 ized in that the total area of the refining zones of the refining surface (1, 2) formed of the second bars (14) and the second grooves (15) is 60 to 90% of the total area of the refining surface (1,2). 4. A refining surface as daimed in claim 3, characterized in that the total area of the refining zones of ihe refining surface (1.2) formed of 25 the second bars (14) and the second grooves (15) is 70 to 80% of the total area of the refining surface (1,2). 5. A refining surface as claimed in any one of the preceding claims, characterized in that the width of the first bars (12) is 15 to 80 mm, the width of the first grooves (13) 5 to 40 mm and the depth of the first grooves 30 (13) 10 to 40 mm. 6. A refining surface as claimed in any one of the preceding claims, characterized in that the first bars (12) and/or the first grooves (13) have a varying width and/or the firat grooves (13) have a varying depth in the direction of travel of said bars (12) or grooves (13). WO 2005/032720 PCT/FI2004/000589 20 7. A refining surface as claimed in any one of the preceding claims, characterized in that the first grooves (13) are pumping on the feed side of the fibrous material to be refined and retentive on the discharge side of the refined material. 5 8.A refining surface as claimd in any one of the preceding claims, characterized in that the width of the second grooves (15) is 1 to 3 mm and the depth of the second grooves (15) 3 to 5 mm. 9. A refining surface as claimed in any one of the preceding claims, characterized in that the second bars (14) and/or the second grooves 10 (15) have a varying width andior the second grooves (15) have a varying depth in the direction of travel of said bars (14) or grooves (15), 10. A refining surface as claimed in any one of the preceding claims, characterized in that said second bars (14) and second grooves (15) airs arranged on the upper surface of the first bars (12) so that they form an 15 angle of 5 to 30° to the radius of the refining surface (1,2). 11. A refining surface as claimed in any one of the preceding claims, characterized in that the number of the second bars (14) of the refining surface zone (16) closest to the feed of the material to be refined is smaller than the number of the second bars (14) closest to the discharge of the refined 20 material, and that the width of the second grooves (15) between the second bars (14) of the zone of the refining surface (1.2) closest to the feed of the ma- terial to be refined is approximately in accordance with the upper limit of the variation range of the width of the grooves (15), and that the width of the sec- ond grooves (15) between the second bars (14) closest to the discharge of the 25 reined material is approximately in accordance with the lower limit of the varia tion range of the width of the grooves (15). 12. A refining surface as claimed in claim 11. characterized in that in the radial direction of the refining surface (1, 2), the depth of the sec- and groove (15) in each refining surface zone (16) of the refining surface (1. 2) 30 is greater at the beginning of the zone (16) than at the end of the zone (16). 13. A refining surface as claimed in claim 12, characterized in that on the bottom of the second groove (15) there is a step at the beginning of each zone (16) for hindering the material to be refined from flowing back- wards. 35 14, A refining surface as claimed in any one of the preceding claims, characterized in that the refining surface (1) is the refining surface (1) WO 2005/032720 PCT/FI2004/000589 21 of a rotor (3) of the refiner, being provided with at least one foll (17), which, when the rotor (3) rotates in the pumping direction, is arranged to produce a lifting force to intensify the mixing of fibres and water, and which foil (17), when the rotor (3) rotates to the non-pumping direction, is arranged to cause a push 5 force to intensify the pumping effect and the passing through of the fibrous ma- teirial. 15, A. refining surface as claimed in claim 14, characterized in that the foil (17) is arranged on the bottom of the first groove (13). 16. A refining surface as claimed in claim 14 OR 5, cnaracter- 10 lzed in that the length of the foil (17) is 30 to 80 mm. preferably 50 to 60 mm, In the transverse direction of the first groove (13). 17, A refining surface as claimed in any one of claims 1 to 16, characterized in that the first bars (12) extend substantially in the line- arly outward direction over the refining surface (1.2). 15 18. A refining surface as claimed in any one of claims 1 to 17, characterized in that the first bars (12) extend in an arc-shaped man- ner outward over the refining surface (1. 2). 19, A blade segment for a refiner intended for defibrating lignocellu- lose-containing material, the refiner comprising at least two refining surfaces 20 (1, 2) arranged coaxially relative to each other, at least one of which refining surfaces (1.2) is arranged to rotate around a shaft (4), and between which re- fining surfaces (1. 2) the material to be defibrated is fed, and which blade sag- ment can be arranged to form at least a part of at least one refining surface (1. 2) and which blade segment camprises first bars (12) extending from the inner 25 circumference of the refining surface (1, 2) to the outer circumference of the refining surface (1, 2) and between them first grooves (13). and the upper sur- faces (18) of which first bars (12) further comprise second grooves (15) con- necting said first grooves (13), and between which second grooves (15) there are second bars (14), 30 characterized in that the second bars (14) are narrower than the first bars (12) and the with of the second bars (14) is 1 to 3 mm. 20. A blade segment as claimed in claim 19, characterized in that the average width of the first bar (12) is 2.5- to 40-fold in respect of the 35 combined, average width of the second bar (14) and the second groove (15). WO 2005/032720 PCT/FI2004/000589 22 21. A blade segment as claimed in claim 19 or 20, character- ized in that the total area of the refining zones of the refining surface (1, 2) formed of the second bars (14) and the second grooves (15) is 60 to 90% of the total area of the refining surface (l,2). 5 22. A blade segment as claimed in claim 21, characterized in that the total area of the refining zones of the refining surface (1,2) formed of the second bars (14) and the second grooves (15) is 70 to 80% of the total area of the refining surface (1.2). 23. A blade segment as claimed in any one of claims 19 to 22, 10 characterized in that the width of the first bars (12) is 15 to 80 mm, the width of the first grooves (13) 5 to 40 mm and the depth of the first grooves (13) 10 to 40 mm. 24. A blade segment as claimed in any one of claims 19 to 23, characterized in that the first bars (12) and/or the first grooves (13) 15 have a varying width and/or the first grooves (,13) have a varying depth in the direction of travel of said bars (12) or grooves (13). 25. A blade segment as claimed in any one of claims 19 to 24, characterized in that the first grooves (13) are pumping on the feed side of the fibrous material to be refined and retentive on the discharge side of 20 the refined material 26. A blade segment as claimed in any one of claims 19 to 25 characterized in that the width of the second grooves (15) is 1 to 3 mm and the depth of the second grooves (15) 3 to 5 mm, 27. A blade segment as claimed in any one of claims 19 to 26, 25 characterized in that the second bars (14) and/or the second grooves (15) have a varying width and/or foe second grooves (15) have a varying depth in the direction of travel of said bars (14) or grooves (15). 28. A blade segment as claimed in any one of claims 19 to 27 characterized in that said second bars (14) and second grooves (15) 30 are arranged on the upper surface of the first bars (12) so that they form an angle of about 5 to 30° to the radius of the refining surface (1.2). A refining surface for a refiner intended for XXX l igooceliulose-conteining natureal The refiining surfes (1, 2) comprised firrt bars 113) contending from tbe inner circumtence of the circumfotence of the refining XXX (1.2) and between than finer grooves (1.3) The oppor surface (18) of the XXX bars (12) further compring first grooves (13) between which second grooves (15) there are second bars (14), which are narrower than the first bars (12). Furtherman, a blude segment for formating refer surfac blades of a refiner untended for defibrning XXX XXX material. |
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00480-kolnp-2006-description complete.pdf
00480-kolnp-2006-international publication.pdf
00480-kolnp-2006-international search report.pdf
00480-kolnp-2006-pct others.pdf
00480-kolnp-2006-pct request.pdf
00480-kolnp-2006-priority document.pdf
480-KOLNP-2006-AMANDED CLAIMS.pdf
480-KOLNP-2006-ASSIGNMENT.1.3.pdf
480-KOLNP-2006-CORRESPONDENCE.1.3.pdf
480-KOLNP-2006-CORRESPONDENCE.pdf
480-KOLNP-2006-DESCRIPTION (COMPLETE).pdf
480-KOLNP-2006-EXAMINATION REPORT REPLY RECIEVED.pdf
480-KOLNP-2006-EXAMINATION REPORT.1.3.pdf
480-KOLNP-2006-FORM 18.1.3.pdf
480-KOLNP-2006-GRANTED-ABSTRACT.pdf
480-KOLNP-2006-GRANTED-CLAIMS.pdf
480-KOLNP-2006-GRANTED-DESCRIPTION (COMPLETE).pdf
480-KOLNP-2006-GRANTED-DRAWINGS.pdf
480-KOLNP-2006-GRANTED-FORM 1.pdf
480-KOLNP-2006-GRANTED-FORM 2.pdf
480-KOLNP-2006-GRANTED-LETTER PATENT.pdf
480-KOLNP-2006-GRANTED-SPECIFICATION.pdf
480-KOLNP-2006-PETITION UNDER RULE 137.pdf
480-KOLNP-2006-REPLY TO EXAMINATION REPORT.1.3.pdf
Patent Number | 247919 | ||||||||||||||||||||||||
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Indian Patent Application Number | 480/KOLNP/2006 | ||||||||||||||||||||||||
PG Journal Number | 23/2011 | ||||||||||||||||||||||||
Publication Date | 10-Jun-2011 | ||||||||||||||||||||||||
Grant Date | 03-Jun-2011 | ||||||||||||||||||||||||
Date of Filing | 02-Mar-2006 | ||||||||||||||||||||||||
Name of Patentee | METSO PAPER, INC. | ||||||||||||||||||||||||
Applicant Address | FABIANINKATU 9 A, FI-00130, HELSINKI, FINLAND | ||||||||||||||||||||||||
Inventors:
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PCT International Classification Number | B02C 7/12 | ||||||||||||||||||||||||
PCT International Application Number | PCT/FI2004/000589 | ||||||||||||||||||||||||
PCT International Filing date | 2004-10-06 | ||||||||||||||||||||||||
PCT Conventions:
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