GRINDING ROLL

Abstract

A grinding roll including a roll body having a cylindrical outer surface extending axially between a pair of opposite ends and a side groove formed at each end of the roll body. The side groove includes a support shoulder recessed from the cylindrical outer surface and/or from surfaces of the opposite ends of the roll body. The grinding roll includes an edge ring including a plurality of spaced receiving cavities and a plurality of wear members. Each wear member is received and retained in at least one of the receiving cavities of the edge ring. The wear members are positioned along the edge ring to define an edge of the grinding roll, and the edge ring is received within each side groove. The wear members are arranged to provide a wear protecting surface which is angled in relation to the cylindrical outer surface of the roll body. The angled wear protecting surface prevents excessive build-up of material on the grinding roll and reduces the need for maintenance.

Claims

1. A grinding roll comprising a roll body having a cylindrical outer surface extending axially between a pair of opposite ends; a side groove formed at each end of the roll body, the side groove including a support shoulder recessed from the cylindrical outer surface and/or from surfaces of the opposite ends of the roll body; an edge ring including a plurality of spaced receiving cavities; and a plurality of wear members each received and retained in at least one of the receiving cavities of the edge ring, wherein the wear members are positioned along the edge ring to define an edge of the grinding roll, wherein the edge ring is received within each side groove, wherein the plurality of wear members is arranged to provide a wear protecting surface which is angled in relation to the cylindrical outer surface of the roll body.

2. The grinding roll according to claim 1, wherein the edge ring is formed from a plurality of edge ring segments.

3. The grinding roll according to claim 1, wherein the side grooves are arranged to provide the support shoulders recessed from each of the opposite end surfaces of the roll body.

4. The grinding roll according to claim 1, wherein the side grooves are arranged to provide the support shoulders recessed from the cylindrical outer surface as well as from each opposite end surface of the roll body.

5. The grinding roll according to claim 1, wherein each of the wear members has an angled outer surface.

6. The grinding roll according to claim 5, wherein the angled outer surface of each of the wear members slopes downwards in a direction towards the end of the roll body.

7. The grinding roll according to claim 5, further comprising a flange ring arranged adjacent the edge ring and attached to an end surfaces of the roll body and/or to the edge ring, the flange ring having an outer edge that extends radially past the outer surface of the roll body.

8. The grinding roll according to claim 7, wherein the flange ring is formed from a plurality of flange ring sections positioned adjacent to each other.

9. The grinding roll according to claim 7, wherein the angled outer surface of each of the wear members partially protrudes with respect to the cylindrical outer surface of the grinding roll and slopes in a direction towards a center of the roll body.

10. The grinding roll according to claim 1, wherein the plurality of wear members is provided in a stepped configuration, each wear member having a first portion and at least a second portion, wherein the first portion is arranged to be aligned with and adjacent an end of the cylindrical outer surface, and the at least second portion is aligned with an end surface of the roll body and arranged radially inwards of the first portion.

11. The grinding roll according to claim 1, wherein the plurality of wear members is arranged in at least two rows on each edge ring, a first row being aligned with and adjacent an end of the cylindrical outer surface, and a second row being aligned with an end surface of the roll body and arranged radially inwards of the first row.

12. A grinding assembly for comminution of material, comprising generally parallel first and second grinding rolls arranged to rotate in opposite directions, towards each other, and separated by a gap, wherein each of the first and second grinding rolls comprises: a roll body having a cylindrical outer surface extending axially between a pair of opposite ends; a side groove formed at each end of the roll body, the side groove including a support shoulder recessed from the cylindrical outer surface and/or from surfaces of the opposite ends of the roll body; an edge ring including a plurality of spaced receiving cavities; and a plurality of wear members each wear member being received and retained in at least one of the receiving cavities of the edge ring, wherein the wear members are positioned along the edge ring to define an edge of the grinding roll, wherein the edge ring is received within each side groove, wherein the first grinding roll comprises a flange ring at each opposite end, said flanges each having an outer edge that extends radially past the cylindrical outer surface of the roll body, and wherein the plurality of wear members of each of the first and second grinding rolls is arranged to provide a wear protecting surface which is angled in relation to the cylindrical outer surface of the respective roll body.

13. The grinding assembly according to claim 12, wherein the plurality of wear members of the first grinding roll is arranged to provide an angled wear protection surface which partly protrudes beyond the cylindrical outer surface of the roll body and which slopes downwards in a direction towards a center of the roll body, and the plurality of wear members of the second grinding roll is arranged to provide an angled wear protection surface which does not protrude beyond the cylindrical outer surface of the roll body and which slopes radially downwards in a direction towards the end of the roll body.

14. The grinding assembly according to claim 12, wherein the plurality of wear members comprises the angled wear protection surface of the first and second grinding rolls.

15. The grinding assembly according to claim 12, wherein the plurality of wear members of the first grinding roll is aligned with the cylindrical outer surface of the roll body; and wherein the plurality of wear members of the second grinding roll is provided in a stepped configuration, wherein the plurality of wear members of the second grinding roll are arranged to provide a first portion and at least a second portion, wherein the first portion is arranged to be aligned with and adjacent an end of the cylindrical outer surface, and the at least second portion is aligned with an end surface of the roll body and arranged radially inwards of the first portion.

16. The grinding assembly according to claim 15, wherein the plurality of wear members of the second grinding roll is arranged in at least two rows on the edge rings, a first row being aligned with and adjacent an end of the cylindrical outer surface forming the first portion, and a second row being aligned with an end surface of the roll body and arranged radially inwards of the first row forming the second portion.

17. A grinding roll comprising a roll body having a cylindrical outer surface extending axially between a pair of opposite ends; a side groove formed at each end of the roll body, the side groove including a support shoulder recessed from the cylindrical outer surface and/or from surfaces of the opposite ends of the roll body; an edge ring including a plurality of spaced receiving cavities; and a plurality of wear members each received and retained in at least one of the receiving cavities of the edge ring, wherein the wear members are positioned along the edge ring to define an edge of the grinding roll, wherein the edge ring is received within each side groove, wherein the plurality of wear members is arranged in a stepped configuration, wherein the plurality of wear members are arranged to provide a first portion and at least a second portion, wherein the first portion is arranged to be aligned with and adjacent an end of the cylindrical outer surface, and the at least second portion is aligned with an end surface of the roll body and arranged radially inwards of the first portion.

18. A grinding roll according to claim 17, wherein the plurality of wear members is arranged in at least two rows on each edge ring, a first row being aligned with and adjacent an end of the cylindrical outer surface forming the first portion, and a second row being aligned with an end surface of the roll body and arranged radially inwards of the first row forming the second portion.

19. An edge ring segment arrangeable at a grinding roll along an edge thereof, the edge ring segment comprising: a plurality of spaced receiving cavities: and a plurality of wear members, each wear member being received and retained in at least one of the receiving cavities of the edge ring segment, wherein the wear members are positioned along the edge ring segment to define an edge of the grinding roll when arranged thereat, and wherein the plurality of wear members is arranged in a stepped configuration such that, when the edge ring segment is arranged at a grinding roll having a cylindrical outer surface extending between a pair of opposing ends, wherein a first portion of each wear member comprises a surface which is aligned with and adjacent an end of the cylindrical outer surface of the grinding roll and a second portion of each wear member protrudes axially from the first portion and is aligned with an end surface of the grinding roll, and is arranged radially inwards of the first portion.

20. The edge ring segment according to claim 19, wherein the plurality of wear members is arranged in at least two rows on the edge ring segment, such that, when the edge ring segment is arranged at a grinding roll having a cylindrical outer surface extending between a pair of opposing ends, a first row is aligned with and adjacent an end of the cylindrical outer surface of the grinding roll forming the first portion, and a second row is aligned with an end surface of the grinding roll and arranged radially inwards of the first row forming the second portion.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The disclosure will be described in more detail with reference to the appended schematic drawings, which show examples of embodiments of the disclosure.

[0035] FIG. 1 is a perspective view of a grinding assembly known in the art.

[0036] FIG. 2 is a section view of an end portion of a grinding assembly known in the art.

[0037] FIG. 3 is a section view of an end portion of a grinding roll and a grinding assembly in accordance with an embodiment of the present disclosure.

[0038] FIG. 4 is a magnified, partially exploded view of a grinding roll in accordance with an embodiment of the present disclosure.

[0039] FIG. 5 is a schematic perspective view of an edge ring segment in accordance with an embodiment of an aspect of the disclosure.

[0040] FIG. 6 is a schematic perspective view of an edge ring segment according to another embodiment of the disclosure.

[0041] FIGS. 7a-c are section views of an end portion of a grinding roll and a grinding assembly in accordance with an embodiment of the disclosure.

[0042] FIGS. 8a-b are section views of an end portion of a grinding roll and a grinding assembly in accordance with an embodiment of the disclosure.

[0043] FIG. 9 is a schematic perspective view of an edge ring segment according to another embodiment of the disclosure.

[0044] FIG. 10 is a perspective view of a grinding assembly in accordance with an embodiment of the disclosure.

DETAILED DESCRIPTION

[0045] The present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the disclosure are shown. The present disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and to fully convey the scope of the disclosure to the skilled addressee. Like reference characters refer to like elements throughout.

[0046] FIG. 1 shows a grinding assembly 1 known in the art for pressure comminution of material such as rock, ore, cement, clinker, and other hard materials. The grinding assembly 1 includes a pair of grinding rolls 2, 3 that are positioned adjacent to each other to define an infeed nip 4. During operation, the grinding rolls 2, 3 rotate toward each other according to the arrows such that material is drawn into the infeed nip 4. The grinding rolls 2, 3 are each respectively rotatable about a shaft 5. A mechanical source of pressure (not shown) bias the grinding rolls 2, 3 toward each other such that the source of pressure crushes the material passing through the infeed nip 4.

[0047] Each grinding roll 2, 3 comprises a roll body 6 having a cylindrical outer surface 7 which extends axially between two opposite ends 8. Each roll body 6 is rotatable about a longitudinal axis that passes through the center of the shaft 5. Each roll body 6 further comprises edge rings 9 arranged at each end of the grinding rolls 2, 3. Each edge ring 9 comprises a plurality of wear members 10 positioned along the respective edge ring to define an edge of the grinding roll 2, 3. Typically, and as shown in FIG. 1, the wear members provide a flat surface edge of the grinding rolls 2, 3. As shown in FIG. 1, one of the grinding rolls 3 further comprises a flange ring 11 having an outer edge that extends radially past the outer surface of the roll body of the grinding roll 3, and positioned axially outward of the roll body 6 of the grinding roll 2. As initially described, a problem with this type of grinding assemblies is that material tend to build up at the corner 12 (see FIG. 2) between the surface of the wear members and the inner surface of the flange. Such material build-up generates increased local loads in this area during operation, which may cause wear members 10 of the non-flanged grinding roll 2 or the flange 11 to be damaged or deformed. To avoid an excessive material build-up, scrapers are used at certain intervals to remove the built-up material in this corner 12.

[0048] The inventor has surprisingly found that by providing a wear protecting surface which is angled in relation to the cylindrical outer surface of the roll body, such excessive material build-up is, however, prevented. FIG. 3 shows an embodiment of an inventive grinding assembly accordingly. In this embodiment, the wear members 22, 23 of the grinding rolls 2, 3 has angled outer surfaces 22′, 23′. As shown, the wear member 22 of the non-flanged grinding roll 2 has an angled outer surface which slopes in a direction towards the end 8 of the roll body 6. More particularly, the angled outer surface 22′ slopes from an end of the wear member 22 which is adjacent and aligned with the cylindrical outer surface 7 downwards to a diagonally opposing end of the wear member 22 which is adjacent and aligned with the end 8 of the roll body 6, thus providing an angled surface extending there between.

[0049] On the other side of the infeed nip 4, the wear member 23 of the flanged roll 3 partially protrudes with respect to the cylindrical outer surface 7 of the grinding roll 3 and slopes in a direction towards the center of the roll body 6, providing an angled wear surface 23′. More particularly, the angled outer surface 23′ slopes from an end of the wear member 23 which is aligned with the end 8 of the roll body 6 and which is at a height radially outwards of the cylindrical outer surface 7 of the roll body 6 to a diagonally opposing end of the wear member 23 which is aligned with and adjacent the cylindrical outer surface 7. Thus, the two angled wear surfaces 22′, 23′ are inversely angled with respect to each other, providing an angled interface 13 there between.

[0050] FIG. 4 shows a portion of the grinding roll 2. As illustrated herein, the plurality of wear members 22 is positioned in an end-to-end configuration to define the edges of the grinding roll 2. In an alternative embodiment, the wear members interlock with each other to form the edge of the grinding roll 2. The wear members 23 of the grinding roll 3 may be provided in the same manner, i.e. in an end-to-end configuration or in an interlocking configuration to form the edge of the grinding roll 3.

[0051] FIG. 4 further shows that each wear member 22 includes an attachment section 20 that is received and retained within one of the receiving cavities 24 formed on the edge ring 9. Although the wear members 22 are each shown being received and retained in one of the receiving cavities 24 the wear members 22 may be configured to include multiple depending sections that would be received in adjacent receiving cavities 24 spaced along the edge ring 9. Thus, in one embodiment one wear member 22 may have multiple attachment sections 20 to be received in adjacent receiving cavities 24.

[0052] The edge ring 9, in turn, is received and retained within a side groove 25 formed at the transition between the outer cylindrical surface 7 and the end surface 8 of the roll body 6. The side groove 25 is defined by the support shoulder 18 and the inner wall 19. The inner wall comprises a plurality of bores 16 that each receive a threaded shaft of a connector 14, for fastening the edge ring 9 to the roll body 6. Correspondingly, the edge ring 9 comprises bores 17 for receiving a head portion of the connector 14. The connector 14 is generally recessed from the end surface of the grinding roll 2 providing a compact fastening means for the edge ring 9. The edge ring 9 of the grinding roll 3 may be arranged at the roll body 6 in the same manner. The recessed arrangement of the connector 14 allows positioning the flange ring 11 axially adjacent to the edge ring 9 of the grinding roll 3.

[0053] FIG. 4, as well as FIGS. 1-3, further shows that the cylindrical outer surface 7 of the grinding rolls 2, 3 are arranged with wear bodies in form of studs 15 arranged in receiving bores on the cylindrical outer surface 7. However, the cylindrical outer surface may also be arranged with other type of wear protection providing a smooth cylindrical outer surface.

[0054] With reference to FIG. 5, an edge ring segment 29 is shown. The edge ring segment 29 comprises bores 17 for receiving a fixing means, such as connector 14 of FIG. 4, to fasten the edge ring segment to a grinding roll. The edge ring segment 29 is shaped such that when arranging a plurality of edge ring segments 29 in an end-to-end configuration, an edge ring is provided. The edge ring segment 29 can therefore be referred to as having a radial extension r parallel with the radial extension of the grinding roll when mounted thereat, and a peripheral extension p. The edge ring segment 29 comprises a plurality of wear members 33 received and retained in spaced receiving cavities of the edge ring segment (not shown in FIG. 5). The wear members 33 are positioned along the edge ring segment 29 to define an edge of the grinding roll when arranged thereat. The wear members are here arranged in a stepped configuration. More particularly, the wear members 33 shown in FIG. 5 provide a first portion 34 and a second portion 35. The first portion 34 comprises a surface 36 providing a first step which forms an edge of the edge ring segment 29 extending along the peripheral extension p thereof. The second portion 35 comprises a surface 37 providing a second step which forms an edge arranged radially inwards of the first step and which extends in the peripheral extension p of the edge ring segment 29. The first and second portions 34, 35 are here made out of first and second rows 32, 31 of wear members 33. That is, the wear member 33 are arranged at the edge ring segment 29 in first and second rows 32, 31 arranged at different radial heights of the edge ring segment.

[0055] FIG. 6 illustrates another edge ring segment 39 comprising wear members 43 provided in a stepped configuration. Here, each wear member has an L-shape. The wear members 43 are arranged in an end-to-end configuration and provide a first and a second portion 44, 45. As for the embodiment shown in FIG. 5, the first portion 44 comprises a surface 46 providing a first step which forms an edge of the edge ring segment 29 extending along the peripheral extension p thereof. The second portion 45 comprises a surface 47 providing a second step which forms an edge arranged radially inwards of the first step and which extends in the peripheral extension p of the edge ring segment 29.

[0056] Referring now to FIGS. 7A-C, a grinding assembly comprising first and second grinding rolls 2, 3 wherein the first grinding roll 2 comprises edge ring segments as that shown in FIG. 5 is illustrated during its operation. In FIG. 7A, the grinding assembly is shown prior to operation. In this embodiment, the second roll 3 comprises the flange 11, arranged thereat as previously described. Furthermore, the edge ring 9 is arranged at the grinding roll 3 in a side groove 26 providing a support shoulder 18 recessed from the end surface of the roll body 6. The edge ring 9 of the second grinding roll 3 further comprises wear members 10 having a flat surface substantially aligned with the cylindrical outer surface 7 of the grinding roll 3. The first grinding roll 2 comprises an edge ring made up of a plurality of edge ring segments 29 of FIG. 5. The edge ring segments 29 are received in a side groove 25 as shown in FIG. 4, providing a support shoulder 18 recessed from the cylindrical outer surface 7 as well as from the end surface 8 of the roll body 6.

[0057] During operation, material build-up 50 will form in the corner between the flat surface of the wear members 10 and the inner surface of the flange 11 of the second grinding roll 3, as shown in FIG. 7B. During further operation, the stepped configuration of the wear members 33 of the first grinding roll 2 provides a pocket to hold material and build an autogenous layer 51 which copies the shape of the material build-up 50 on the second grinding roll 3. Due to the decreasing pressure between the grinding rolls 2, 3 towards the ends thereof, the shape of the material build-up or autogenous layer 50, 51 is generally triangular in cross-section. The autogenous layer protects the surface of the wear members 10 of the second grinding roll 3 and the surface 37 of the second portion 35 of the wear members 33 of the second grinding roll 3 from wear. The so formed autogenous layers 50, 51 thus provide angled wear protecting surfaces of the first and second grinding roll 2, 3.

[0058] Referring now to FIGS. 8A-B, a grinding assembly comprising first and second grinding rolls 2, 3 wherein the first grinding roll 2 comprises edge ring segments as that shown in FIG. 5 and FIGS. 7A-C is illustrated during its operation. In FIG. 8A, the grinding assembly is shown prior to operation. In this embodiment, the second roll 3 comprises the flange 11, arranged thereat as previously described. The first grinding roll 2 comprises an edge ring made up of a plurality of edge ring segments 29 as that shown in FIG. 5 and FIGS. 7A-C. The edge ring segments 29 are received in a side groove 25 as shown in FIG. 4, providing a support shoulder 18 recessed from the cylindrical outer surface 7 as well as from the end surface 8 of the roll body 6. Furthermore, the second grinding roll 3 also comprises an edge ring made up of a plurality of edge ring segments 29 as that shown in FIG. 5 and thus having the same structure as that of the first grinding roll 2.

[0059] During operation, material build-up 50 will form in the corner between the stepped configuration of the wear members 33 of the second grinding roll and the inner surface of the flange 11 of the second grinding roll 3, as shown in FIG. 7B. During further operation, the stepped configuration of the wear members 33 of the first grinding roll 2 provides a pocket to hold material and build an autogenous layer 51 which copies the shape of the material build-up 50 on the second grinding roll 3. Due to the decreasing pressure between the grinding rolls 2, 3 towards the ends thereof, the shape of the material build-up or autogenous layer 50, 51 is generally triangular in cross-section. The autogenous layer protects the surface of the wear members 33 of the first and second grinding rolls 2, 3 from wear. The so formed autogenous layers 50, 51 thus provide angled wear protecting surfaces of the first and second grinding roll 2, 3.

[0060] FIG. 9 illustrates another edge ring segment 39 comprising wear members 43 provided in a stepped configuration. Here, each wear member has an L-shape, similar to that of FIG. 6. It is clear that a design similar to that of FIG. 5 is also possible, having wear elements arranged in a stepped configuration. The wear members 43 are arranged in an end-to-end configuration and provide a first and a second portion 44, 45. Similar to the embodiment shown in FIG. 5, the first portion 44 comprises a surface 46 providing a first step which forms an edge of the edge ring segment 29 extending along the peripheral extension p thereof. The second portion 45 comprises a surface 47 providing a second step which forms an edge arranged radially inwards of the first step and which extends in the peripheral extension p of the edge ring segment 29. In addition, sloping elements 48 are arranged on the surface 47. The sloping elements are arranged with a distance between them, thus creating pockets therebetween. These pockets will during use be filled with material creating a stronger autogenous layer which is prevented from moving in a circumferential direction.

[0061] FIG. 10 discloses a grinding assembly 1 in which both grinding rolls 2, 3 are provided with edge ring segments comprising sloping elements 48 as described in FIG. 9. This design provides improved retention of material creating a strong autogenous layer protecting the grinding rolls and flanges 11. It is clear that such sloping elements can be provided on only one of the grinding rolls 2, 3 and be combined with any of the other edge ring designs as defined in FIGS. 3-8B.

[0062] The skilled person realizes that a number of modifications of the embodiments described herein are possible without departing from the scope of the disclosure, which is defined in the appended claims.