Refining element, a support structure for the refining elements and a conical refiner

Abstract

The object of the invention is a replaceable refining element (52, 62, 72, 82), a support structure (31, 41) for the refining elements (52, 62, 72, 82) and a conical refiner for preparation of paper pulp. The conical refiner comprises a stator and a rotor constituted by a series of replaceable refining elements (52, 62, 72, 82), the stator and / or the rotor comprising a support structure (31, 41) mounted to the rotor and / or the stator to which support structure (31, 41) the refining elements (52, 62, 72, 82) are mounted. The support structure (31, 41) comprises a support element (34, 44) having regular polygonal conical support surface (35, 45) for the replaceable refining elements (52, 62, 72, 82). The refining element (52, 62, 72, 82) for a conical refiner's rotor and / or stator comprises a planar mounting surface.

Description

[0001] REFINING ELEMENT , A SUPPORT STRUCTURE FOR THE REFINING

[0002] ELEMENTS AND A CONICAL REFINER

[0003] The object of the present invention is a refining element , a support structure for the refining elements and a conical refiner .

[0004] Disc or conical refiners are used for refining pulp or the like for example for the use of the pulp and paper industry . Conical refiners are generally constructed of at least two refining cones ( stator and rotor) , one inside the other, having refining surfaces facing each other . The material to be refined is treated in a gap defined between the two refining cones rotating relative to each other . The material moves in the grooves formed between bars located on the conical refining surfaces , providing a transport function and a mechanism for material stapling at the bar crossings . The refiners can comprise replaceable refining segments or the refining surface may be a part of the cone itself . The replaceable refining elements are mounted to the concave or convex mounting surface of the support structure of the conical refiner and the underlying support structure is mounted to the body parts of the conical refiner, i . e . , the body of the rotor and that of the stator . Generally, the refining cones are comprising refining elements , support structure and mounting means and some of the mentioned parts can be integrated together in one piece structure . With mounting means the refining cones are mounted either to the body of the stator or to the rotating shaft , or to other rotating part , of the rotor body . The replaceable refining elements are used because the refining surfaces of the conical refiner wear during the use . The mounting surface of the conical refiner' s support structure for the replaceable refining elements are either concave or convex (a stator or a rotor) .

[0005] An exemplary prior art solution is presented in document EP2063019B1 , which describes a method for making the refining elements for a conical refiner . The refining elements are formed from a flat metal sheet , in a first step, by machining the required curved surface to a narrow metal sheet section having a shape of a truncated sector . Also, the grooves (or bars ) are formed to these parts in a second step of machining . The refining elements are mounted to supporting rings having a curved mounting surface towards the refining elements , which on their part have grooves machined to their mounting surfaces , the grooves matching the curvature of the supporting rings . The refining elements are directly mounted to the supporting rings . The refining elements are narrow and are welded together to provide the refining surface with required strength and stability since the refining elements are supported only by their contact to the supporting rings . It is repeated many times in the document that this kind of refining elements cannot be manufactured by casting processes .

[0006] The present invention produces a cast replaceable refining element for a conical refiner which refining element uses less material than the prior art cast refining elements and is therefore much lighter than the prior art solutions . This saving of the material resources leads to significant cost savings in the production of refining elements . The production of the replaceable refining elements according to the invention is also more efficient than the production of prior art refining elements and therefore the production costs , such as energy and material , of the refining elements according to the invention are also lower . The refining elements are made by casting which enables unlimited design without any additional steps in the manufacture of the refining elements as was the case in mentioned prior art document EP2063019B1 . The refining elements according to the invention need only two production steps , i . e . casting the element and finishing the mounting and the refining surfaces by machining . The manufacturing process of the refining element according to the invention is therefore much faster and more cost efficient . The casting process can use any modern casting technology . The flat mounting surfaces of the refining elements can be machined for several pieces at a time .

[0007] Some other prior art refining elements have concave / convex mounting surfaces facing the refiner' s body parts and use therefore unnecessary amount of raw material and, additionally, the elements are difficult to manufacture to the required mounting surface ( convex or concave) tolerances .

[0008] An object of the present invention is to eliminate drawbacks of the prior art : 1 ) by producing by casting a costefficient replaceable refining element comprising a flat mounting surface facing the support structure of a conical refiner, 2 ) by providing a support structure for the refining elements and 3 ) by providing a conical refiner comprising the refining elements and the support structure . The refining elements according to the invention may be used in any prior art conical refiner after the support structure of the conical refiner is replaced with the support structure of the invention . The support structure of the invention comprises curved mounting surface facing the body part of the refiner and a regular polygonal mounting surface facing the refining elements , the regular polygonal mounting surface providing a flat mounting surface for each refining element . The polygonal mounting surface of the support structure covers at least parts of the support structure surface facing the refining elements , which parts are positioned advantageously against the longitudinal / axial edges of the refining element and against the mounting points of the refining element . The mounting surfaces facing the body parts of the conical refiner are similar to that in the prior art conical design and therefore the new support structure may be easily assembled directly to a prior art conical refiner .

[0009] Another aim of the present invention is to produce a replaceable refining element which is easier to manufacture . This is achieved with modern casting processes and with a flat mounting surface of the refining element . Casting process also enables easier production of wider, in circumferential direction, refining elements than machining .

[0010] Yet another aim of the present invention is to produce a support structure for replaceable refining elements the support structure comprising a regular polygonal truncated pyramid-shaped support surface for the replaceable refining elements .

[0011] Yet another aim of the invention is to produce a conical refiner comprising the replaceable refining elements and the support structure of the invention .

[0012] The present invention relates to a replaceable refining element for a conical refiner and a conical refiner comprising a new support structure where the replaceable refining elements of the invention are mounted . The new support structure and replaceable refining elements can be used both in the stator and in the rotor of the conical refiner .

[0013] In the following, the invention will be described in more detail by the aid of some preferred embodiments with reference to the simplified and diagrammatic drawings attached, wherein

[0014] Fig . 1 presents a simplified and partial view of a prior art support structure of the outer refining cone,

[0015] Fig . 2 presents a simplified and partial view of a prior art support structure of the inner refining cone ,

[0016] Fig . 3 presents a simplified and partial view of a support structure of the outer cone according to the invention,

[0017] Fig . 4 presents a simplified and partial view of a support structure of the inner cone according to the invention,

[0018] Fig . 5 presents one advantageous embodiment of a refining element for the outer cone ,

[0019] Fig . 6 presents one advantageous embodiment of a refining element for the inner cone ,

[0020] Fig . 7 presents one advantageous embodiment of the lightened refining element for the outer cone ,

[0021] Fig . 8 presents one advantageous embodiment of the lightened refining element for the inner cone ,

[0022] Fig . 9 presents one advantageous embodiment of the lightened support structure for the outer cone ,

[0023] Fig . 10 presents one advantageous embodiment of the lightened support structure for the inner cone , and

[0024] Fig . 11 presents a simplified cross-section of the support structure together with the refining element .

[0025] Fig . 1 presents a simplified and partial view of a prior art support structure 1 of the outer refining cone of a conical refiner . A replaceable refining element 2 is mounted to the support structure 1 . The support structure 1 has curved ( convex) mounting means 3 and 4 facing the body of the stator . The mounting means 3 and 4 have been presented in a very simplified way and the structure / shape of the mounting means can vary as in any used prior art support structure . The support structure 1 has curved (concave) mounting surface 5 for the refining elements 2 . The refining elements 2 are forming uniform concave refining surface 6 for the outer cone of the conical refiner . The refining elements 2 are mounted directly to the support structure ' s concave inner surface 5 . This means that the refining elements 2 have even thickness throughout each refining element . The convex mounting surface of the prior art refining elements 2 are difficult and slow to manufacture to the required tolerances .

[0026] Fig . 2 presents a simplified and partial view of a prior art support structure 11 of the inner cone of a conical refiner . A refining element 12 is mounted to the support structure 11 . The support structure 11 comprises mounting means 13 and 14 for fastening the inner cone to the body of the rotor, i . e . to the shaft of the refiner . The mounting means 13 and 14 are presented in a very simplified way and the structure / shape can vary as in any used prior art support structure . The support structure 11 has also curved (convex) mounting surface 15 for the refining elements 12 . The refining elements 12 are forming uniform convex refining surface 16 for the inner cone of the conical refiner . The refining elements 12 are mounted directly to the support structure' s convex outer surface 15 . This means that the refining elements 12 have even thickness throughout each refining element . The concave mounting surface of the prior art refining elements 12 are difficult and slow to manufacture to the required tolerances .

[0027] Fig . 3 presents a simplified and partial view of the support structure 31 according to the invention which support structure is mounted to the body of the stator . The support structure 31 comprises mounting means 32 and 33 which mounting means are connecting the support structure to the body of the stator . The mounting means 32 and 33 of the support structure 31 for mounting the support structure to the body of the stator are similar to any prior art mounting means of the prior art support structure that the new support structure is replacing .

[0028] The support structure 31 of the invention has a support element 34 for the replaceable refining elements which support element is connected to the mounting means 32 and 33 . The support element 34 has a regular polygonal support surface 35 for the replaceable refining elements on the face opposite to the face connected to the mounting means 32 . The mounting means 32 can have either regular polygonal or curved / concave mounting surface 36 for the support element 34 . In Fig . 3 the mounting surface 36 is a regular polygonal surface . I f the mounting means 32 has a curved / concave mounting surface 36 for the support element 34 , the support element has a curved / convex mounting surface facing the mounting means 32 and a regular polygonal surface 35 against the replaceable refining elements . The mounting means 33 , which are situated at the smaller end of the truncated cone in this embodiment , are advantageously connected to the end rim of the regular polygonal support element 34 . Also support structures which have two supporting / mounting rings are known in the prior art (EP2063019B1 ) . The support element 34 is then mounted directly to the rings .

[0029] The support surface 35 of the support element 34 for the refining elements is formed of a regular polygonal truncated pyramid . When the mounting surface 35 for each refining element is planar the manufacturing of the refining elements is easy, and the manufacturing costs are reduced . The support surface 35 of the support element 34 can be a uniform truncated polygonal pyramid surface, or the support element can include several holes for material saving purposes . The support element 34 produces support advantageously at least partly to the longitudinal / axial edges of the refining elements and for attaching points for the mounting of the refining elements . One advantageous embodiment of the lightened support element of the support structure is presented in Fig . 9. The support structure 34 can be manufactured also in other configurations . A feature essential to the working of the invention is the use of prior art mounting surfaces of the mounting means 32 and 33 to mount the support structure 31 to the body of the stator . An equally essential feature is the use of a regular polygonal mounting surface 35 facing the replaceable refining elements . Another advantageous embodiment of the support element 34 is presented in Fig . 10 .

[0030] Fig . 4 presents a simplified and partial view of the support structure 41 ( for the inner refining cone ) which is to be mounted to the conical refiner . The support structure 41 comprises mounting means 42 and 43 which mounting means are connecting the support structure to the inner structures , including the shaft , of the rotor of the conical refiner and a support element 44 . The support element 44 is connected to the mounting means 42 and 43 , and has a regular polygonal surface 45 on the face opposite to the mounting means for the replaceable refining elements . The mounting means 42 and 43 can have either regular polygonal or curved / convex mounting surfaces 46 and 47 for the communication with the support element 44 . In Fig . 4 the mounting surfaces 46 and 47 are regular polygonal surfaces . If the mounting means 42 and 43 have curved / convex mounting surfaces 46 and 47 for the communication with the support element 44 , the support element has a curved / concave mounting surface facing the mounting means 42 and 43 , and a regular polygonal surface 45 against the replaceable refining elements .

[0031] The mounting surfaces of the mounting means 42 and 43 of the support structure 41 for the mounting of the support structure to the rotor of the conical refiner are similar to any prior art mounting means of the prior art support structures . The support surface 45 of the support element 44 for the replaceable refining elements is formed of a regular polygonal pyramid mounting surface . When the mounting surface for each refining element is planar the manufacturing of the refining elements is easy, and the manufacturing costs are reduced . The support surface 45 of the support element 41 can be a uniform and solid truncated polygonal pyramid surface , or the support element can include several holes for material saving purposes . The support element 41 produces support advantageously at least partly for the edges of the refining elements and for attaching points for the mounting of the refining elements . One advantageous embodiment of the lightened support element of the support structure is presented in Fig . 10 . The support structure 41 can be manufactured also in other configurations . The features essential to the working of the invention are the prior art mounting surfaces of the mounting means 42 and 43 to mount the support structure 41 to the body of the rotor of the refiner and the novel and inventive use of a regular polygonal mounting surface 45 facing the replaceable refining elements . Another advantageous embodiment of the support element 44 is presented in Fig . 10 . The support surface of the support structure for replaceable refining elements is formed of a regular polygonal truncated pyramidshaped mounting surface .

[0032] To the support structures of Fig . 3 and Fig . 4 can be mounted 1-3 rows of refining element in the direction of the rotating axis of the conical refiner . The number of the rows depends on the si ze of the conical refiner . The support structure can be constructed with individual support element sectors combined together to form the regular polygonal truncated pyramid-shaped surface for the refining elements . Another embodiment is to construct the regular polygonal truncated pyramid-shaped surface for the refining elements by bending a single flat metal sheet into the desired form. Also, the support surface can be formed with two or more bended metal sheets combined together .

[0033] Fig . 5 presents one advantageous embodiment of the replaceable refining element 52 . The Fig . 5 is a simplified cross-sectional view of the refining element 52 for the outer cone of the conical refiner . The refining element 52 comprises a first surface 53 , which is the refining surface and a second surface 54 opposite to the first surface, which second surface is the mounting surface . This refining element 52 of Fig . 5 is mounted to the outer cone' s support structure 31 presented in Fig . 3 . The first surface 53 of the refining element 52 is concave , and the first surfaces of the refining elements assembled circumferentially side by side to each other are forming a uniform curved / circular refining surface for the outer refining cone . In other words , the cross-section of the refining surface of each refining element 52 is arcuate ( a part of an arc of the circle of the refining surface ) . The second surface 54 of the refining element 52 is planar . Planar mounting surface is much easier to manufacture than concave mounting surface of the prior art refining element . The mounting of the refining element 52 to the support structure is done by bolts , alien bolt s , hex screws , or by some other equivalent mounting means . The mounting points are advantageously situated to the corners , or longitudinal / axial edge areas of the refining element 52 where the material thickness is greater than in the circumferential middle of the refining element . The positions of the mounting points can be seen in Fig . 10 . The mounting of the refining element 52 to precise position can be ensured by using one or more centering pins and / or centering holes in the refining element . Also , some other centering methods and means can be used, such as step form, separate wedge , taper pin or conical bolts / screws .

[0034] Fig . 6 presents one advantageous embodiment of the refining element 62 . Fig . 6 is a simplified cross-sectional view of the refining element 62 for the inner cone of the conical refiner (the rotor) . The refining element 62 comprises a first surface 63 , which is the refining surface and a second surface 64 opposite to the first surface , which second surface is the mounting surface . This refining element 62 of Fig . 6 is mounted to the inner cone support structure 41 presented in Fig . 4 . The first surface 63 of the refining element 62 is convex, and the first surfaces of the refining elements assembled circumferentially side by side to each other are forming a uniform curved / circular refining surface for the inner refining cone . In other words , the cross-section of the refining surface of each refining element 62 is arcuate ( a part of an arc of the circle of the refining surface ) . The second surface 64 of the refining element 62 is planar . Planar mounting surface is much easier to manufacture than convex mounting surface of the prior art refining element . The mounting of the refining element 62 to the support structure is done for instance by bolts or by any other equivalent mounting means . The mounting points are advantageously situated to , in the circumferential direction, the center of the refining element 62 where the material thickness is greater than in the corners or longitudinal / axial edge areas of the refining element . The positions of the mounting points can be seen Fig . 9 . The mounting of the refining element 62 to precise position can be ensured by using one or more centering pins and / or centering holes in the refining element . Fig . 7 presents another advantageous embodiment of the refining element 72 . The Fig . 7 is a simplified cross- sectional view of the refining element 72 for the outer cone of the conical refiner . The refining element 72 comprises a first surface 73 , which is the refining surface and a second surface 74 opposite to the first surface, which second surface is the mounting surface . This refining element 72 of Fig . 7 is mounted to the outer cone' s support structure 31 presented in Fig . 3 . The first surface 73 of the refining element 72 is concave , and the first surfaces of the refining elements assembled circumferentially side by side to each other are forming a uniform curved / circular refining surface for the outer refining cone . The second surface 74 , i . e . the mounting surface , of the refining element 72 is at least partly planar . Planar sections of the mounting surface are positioned for example to the longitudinal / axial edges of the refining element 72 and to the mounting points of the refining element . When the first surface 73 of the refining element 72 is concave the mounting points are advantageously situated near the longitudinal / axial edges / corners of the refining element since the material thickness is greater there . The refining element 72 has also advantageously planar mounting section in the circumferential middle of the refining element since the material thickness is there thin and the refining element needs support to maintain its shape . When the second surface 74 is only partly planar, having lightening cavities 75 , the refining element can be made with even smaller amount of raw material .

[0035] Fig . 8 presents another advantageous embodiment of the refining element . Fig . 8 is a simplified cross-sectional view of the refining element 82 for the inner cone of the conical refiner (the rotor) . The refining element 82 comprises a first surface 83 , which is the refining surface and a second surface 84 opposite to the first surface , which second surface is the mounting surface . This refining element 82 of Fig . 8 is mounted to the inner cones support structure 41 presented in Fig . 4 . The first surface 83 of the refining element 82 is convex, and the first surfaces of the refining elements are forming a uniform curved / circular refining surface for the inner refining cone . The second surface 84 of the refining element 82 is at least partly planar . Planar sections of the mounting surface are positioned for example to the longitudinal / axial edges of the refining element 82 and to the mounting points of the refining element . When the refining surface of the refining element is convex the mounting points are advantageously situated to the circumferentially middle section of the refining element 82 since the material thickness is greater in the middle . When the second surface 84 is only partly planar, having lightening cavities 85 , the refining element 82 can be made with even smaller amount of raw material .

[0036] The refining elements 72 and 82 of Fig . 7 and Fig . 8 have the total mounting surface area (the area in contact with the support element 34 and 44 ) of the mounting surface smaller than the outline area (the area which the whole refining element covers ) of the refining element .

[0037] When mounted onto the support structure 31 and / or 41 the refining elements 52 , 62 , 72 and 82 are arranged to form a uniform circular conical refining surface for both the rotor and the stator . Also , when mounted onto the support structure 31 and / or 41 the refining elements 52 , 62 , 72 and 82 form a regular polygonal truncated pyramid-like mounting surface for both the rotor and the stator .

[0038] Figs . 9 and 10 are presenting one flat section of the lightened support element 94 of the support structure . Fig . 9 is the support element 94 for the refining element having convex refining surface since the mounting points 95 of the replaceable refining element are situated to the circumferential middle of the flat support surface . The support element 94 comprises holes 96 , which holes are designed to lighten the support structure . Holes 96 in Fig . 9 are polygonal .

[0039] Fig . 10 is the support element 104 for the refining element having concave refining surface since the mounting points 105 of the replaceable refining element are situated to the corners of the flat support surface . The support element 104 comprises holes 106 , which holes are designed to lighten the support structure . Holes 106 in Fig . 10 are circular .

[0040] The holes 96 and 106 of Figs . 9 and 10 have polygonal or circular shapes , but the shapes are not limited to those, and they can vary to any preferred shape .

[0041] Fig . 11 presents a simplified cross-section of the support structure 44 together with the refining element 82 for the inner refining cone . The refining element 82 is mounted to the support structure 44 with bolts (not shown) in accordance with the line 111 . Cavities 85 for lightening of the refining element 82 are formed between the support structure 44 and the refining element . The refining surface 112 is formed to the refining element with bars 113 and grooves 114 . The refining element 44 is resting on the support element 44 at least partly at the longitudinal / axial edges 115 of the refining element and at the mounting point 116 of the refining element . The refining element 82 can be supported also at other points / areas of the refining element .

[0042] The support element 34 , 44 , 94 or 104 of the inner and / or outer cone can be shorter ( in the direction of the refiner' s axis ) than the refining elements 52 , 62 , 72 or 82 and therefore the support cannot be provided to the end rim or rims of the refining elements . The refining elements 52 , 62 , 72 or 82 are supported by the support element 34 , 44 , 94 or 104 at least partly at the longitudinal / axial edges of the refining elements and at the mounting points of the refining elements . The refining elements 52 , 62 , 72 or 82 are also supported at the mounting points of the refining elements , especially when the mounting points are in the circumferential middle of the refining element , shown by line 111 .

[0043] The support structures 31 and 41 of Fig . 3 and Fig . 4 can also be mounted to the refining cones having non replaceable refining surface . This modification enables in the future to just mount new refining elements to the conical refiner .

[0044] It is obvious to the person skilled in the art that the invention is not limited solely to the examples described above , but that it may be varied within the scope of the claims presented below .

Claims

CLAIMS1. A support structure (31, 41) mounted with mounting means (32, 33, 42, 43) to a body of a rotor and / or a body of the stator of a conical refiner to which support structure (31, 41) replaceable refining elements (52, 62, 72, 82) are mounted, characterized in that the support structure (31, 41) comprises support element (34, 44) forming a truncated regular polygonal pyramid-shaped support surface (35, 45) for the replaceable refining elements (52, 62, 72, 82) .

2. The support structure (31, 41) according to claim 1, characterized in that the mounting means (32, 42, 43) of the support structure (31, 41) comprises regular polygonal mounting surfaces (36, 46, 47) for the support element (34, 44) .

3. The support structure (31, 41) according to claim 1 or 2, characterized in that the mounting means (32, 42, 43) of the support structure (31, 41) comprises curved mounting surfaces (36, 46, 47) for the support element (34, 44) .

4. The support structure (31, 41) according to any one of claims 1-3, characterized in that the support element (34, 44) of the support structure (31, 41) comprises holes (96, 106) for lightening the support structure (31, 41) .

5. The support structure (31, 41) according to any one of claims 1-4, characterized in that each support element (34, 44) comprises one or more centering means for the assembly of the refining element (52, 62, 72, 82) to the support structure (31, 41) of the rotor and / or stator.

6. The support structure (31, 41) according to claim 5, characterized in that the centering means are centering pins or holes, a step form, a separate wedge, a taper pin or conical bolts / screws .

7. A refining element (52, 62, 72, 82) for a conical refiner's rotor and / or stator, the refining element (52, 62, 72, 82) comprising a first surface (53, 63, 73, 83) and a second surface (54, 64, 74, 84) where the first surface (53, 63, 73, 83) is a refining surface and the second surface (54, 64, 74, 84) comprises a mounting surface, characterized in that the mounting surface of each refining element (52, 62, 72, 82) is planar and when mounted onto the support structure (31, 41) the refining elements (52, 62, 72, 82) are arranged to form a regular polygonal truncated pyramidshaped mounting surface for both the rotor and the stator.

8. The refining element (52, 62, 72, 82) according to claim7, characterized in that the total surface area of the mounting surface is smaller than the outline area of the refining element (52, 62, 72, 82) .

9. The refining element (52, 62, 72, 82) according to claim 7 or 8, characterized in that the refining element (52, 62, 72, 82) comprises cavities (75, 85) at the second surface (74, 84) for lightening the refining element (52, 62, 72, 82) .

10. The refining element (52, 62, 72, 82) according to any one of claims 7-9, characterized in that each refining element (52, 62, 72, 82) comprises one or more centeringmeans for the assembly to the support structure (31, 41) of the rotor and / or stator.

11. The refining element (52, 62, 72, 82) according to claim 10, characterized in that centering means are centering pins or holes, a step form, a separate wedge, a taper pin or conical bolts / screws .

12. A conical refiner for preparation of paper pulp, the conical refiner comprising a conical stator and a conical rotor constituted by a series of replaceable refining elements (52, 62, 72, 82) having first surfaces (53, 63, 73, 83) as refining surfaces, the stator and / or the rotor comprising a support structure (31, 41) mounted with mounting means (32, 33, 42, 43) to the rotor and / or the stator to which support structure (31, 41) the refining elements (52, 62, 72, 82) are mounted, characterized in that the conical refiner comprises the support structure (31, 41) according to claim 1.

13. The conical refiner according to claim 12, characterized in that the conical refiner comprises the refining elements (52, 62, 72, 82) according to claim 7.

14. The conical refiner according to claim 13, characterized in that when mounted onto the support structure (31, 41) the refining elements (52, 62, 72, 82) are arranged to form a uniform circular conical refining surface for both the rotor and the stator.

15. The conical refiner according to claim 13 or 14, characterized in that when mounted onto the mounting means (32, 33, 42, 43) the support structure (31, 41) is arrangedto form a regular polygonal truncated pyramid-shaped mounting surface for the refining elements (52, 62, 72,82) .

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