Patent Application
20220410166
The present disclosure relates to a grinding roll and a grinding assembly for comminution of materials comprising the grinding roll.
When comminuting or crushing materials, such that rock, ore, cement clinker or other hard materials, using grinding assemblies or the like is well known in the art. The grinding assembly may have two grinding rolls for the pressure comminution of materials. Preferably, the two grinding rolls are arranged generally parallel and configured to rotate opposite directions, towards each other, wherein the two grinding rolls are separated by a gap. The material to be comminuted is fed by gravity or choke-fed into the gap. One type of grinding assembly is called high pressure grinding rollers or high pressure roller crusher. Sometimes, this type of grinding assembly uses a crushing technique called interparticle crushing. Here, the material to be comminuted or crushed is crushed not only by the crushing surface of the rolls, but also by particles in the material to be comminuted or crushed, hence the name interparticle crushing. However, a problem that may occur when feeding the material into the gap is to keep the material between the grinding roll(s) and to direct the material into the gap.
In an attempt to meet this problem, European Patent EP2756886B1 suggests introducing flanges on one of the two grinding rolls.
Such flanges are exposed to a lot of wear from the material to be crushed, but the flanges are also exposed to pressure exerted by the material.
Further, flanges may be exposed to different amount of wear on different parts of the flange.
Even further, such flanges may, in case of skewing, interfere with the edges of the opposite grinding roll and cause damage to both the flanges as well as the edges of the opposite grinding roll.
Thus, the conventional grinding rolls arranged with flanges are associated with several drawbacks. There is thus a need in the art for an improved flange.
An object of the disclosure is to provide for an increased life of the flange during operation of a grinding assembly.
Another object of the disclosure is to provide for an improved flange design compared to conventional flanges known in the art.
Another object of the disclosure is to provide for a more stable grinding roll during skewing events, wherein the grinding roll comprises at least one flange.
According to a first aspect of the disclosure, these and other objects are achieved, in full or at least in part, by a grinding roll comprising:
a roll body having a cylindrical outer surface extending axially between a first end and a second end of the roll body;
a flange attached to at least one of the first and second end of the roll body;
the flange having an outer edge that extends radially past the cylindrical outer surface of the roll body;
the flange having a first surface and a second surface, the first surface forming a perpendicular continuing surface with the cylindrical outer surface of the roll body, and the second surface forms a continuation of the at least one of the first and second end of the roll body; and
the flange comprises wear protection liner elements on the first surface.
According to the disclosure liner elements on the first surface comprises at least one radially lower part adjacent the cylindrical outer surface, and at least one radially upper part adjacent the outer edge of the flange,
wherein the at least one radially lower part comprises a first type of wear protection liner elements and the at least one radially upper part comprises a second type of wear protection liner elements, and wherein an average covering area of the second type of wear protection liner elements is larger than that of the first type of wear protection liner elements.
By the term “attached” is here meant that the flange is fastened or mounted to, or in close proximity to, the at least one of the first and second end of the roll body in order to be kept in place. The flange is attached to the at least one of the first and second end of the roll body by means of a bolt and nut arrangement or screws. However, it should be noted that adhesives, welding, Velcro, magnets, or other, similar means may be used as well. In this way, it is possible to remove or replace the flange in an easy way. According to one non-limiting example, the flange may be attached to the roll body in one piece, wherein the flange is in one piece. According to another non-limiting example, the flange may be divided into a plurality of segments, wherein each segment may be attached to the roll body. The flange may be divided into the plurality of segments in order to facilitate manufacturing and mounting of the same. Preferably, the plurality of segments may be attached to each other by stitch plates, sometimes also called fish plate or joint plates, or the like.
By the term “first surface” is here meant a surface facing inwardly over the cylindrical outer surface of the roll body and forming a perpendicular continuing surface with the cylindrical outer surface.
By the term “second surface” is here meant the surface of the flange facing exterior or outwardly of the roller body forming a continuing surface with the at least one of the first and second end of the roll body.
When the flange is attached to the at least one of the first and second end of the roll body, the first surface is exposed to a lot of wear from the material during operation, while the second surface is not. Thus, it is the first surface that should be improved such that the lifetime of the flange may be increased. Therefore, by introducing wear protection liner elements on the first surface of the flange, it is possible to provide for a more durable flange such that the lifetime of the flange is increased.
The disclosed grinding roll may be advantageous as it allows for the wear protection liner elements to vary over the first surface of the flange, wherein the radially lower part comprises the first type of wear protection liner elements and the radially upper part comprises the second type of wear protection liner elements. This is advantageous because the radially lower and the radially upper part of the first surface of the flange usually are exposed to different wear. By introducing the first and second types of wear protection liner elements, wherein an average covering area of the second type of wear protection liner elements is larger than that of the first type of wear protection liner elements, provides for that it is possible to tailor the respective type of wear protection liner elements based on the wear on the flange. Although the average covering area of the second type of wear protection liner elements is larger than that of the first type of wear protection liner element, it should be noted that a covering area of individual elements of the second type of wear protection liner elements may be smaller than a covering area of individual element of the first type of wear protection liner element and vice versa. Preferably, the first type of wear protection liner elements should be fabricated with high strength “ductile” material to resist high load. Preferably, the second type of wear protection liner elements uses a wear resistant material such that tungsten carbide or ceramics. With the present disclosure, a more durable flange and hence, the lifetime of the flange may be improved.
According to an embodiment, the covering area of each of the second type of wear protection liner elements is larger than that of each of the first type of wear protection liner elements.
According to an embodiment, the first type of wear protection liner elements is arranged as a mosaic pattern on the at least one radially lower part of the flange.
An advantage with this embodiment is that efficient use of the first type of wear protection liner elements is provided. Thus, in the at least one radially lower part of the flange, there are little or no material movements in relation to the first surface of the flange during operation and hence, the lower part is not exposed to excessive abrasive wear based on the material movements. All material in the lower part of the flange may be exposed to crushing forces and the material is moving with the flange and hence, creates little or no abrasive wear on the flange. As there is little or no abrasive wear on the flange in this radially lower part of the flange, there is no need for a wear protection liner element with full covering of the flange. On the other hand, this area may be subjected to large axial forces, which may cause the first type of wear protection liner elements to crack should each wear protection liner elements have a large covering area. Thus, this first type of wear protection liner elements is preferably arranged in a mosaic pattern. The wear protection liner elements may have a hexagonal shape and may be arranged such that they do not cover the entire surface of this area.
According to an embodiment, the first type of wear protection liner elements comprises studs arranged in recesses provided in the at least one radially lower part of the flange.
An advantage with this embodiment is that the studs may be removable or replaceable when worn out. Again, as discussed in previous embodiment, the low or no abrasive wear in this area allows for not fully covering wear protection. Instead the axial forces are more troublesome in this area. Studs having a small wear protection liner area facing the axial forces of the material to be grinded and having an axial extension within the flange will handle these axial forces well in this at least one radially lower part of the flange. Such studs are easy to manufacture. Hence, this embodiment may provide for an increased lifetime of the flange.
According to an embodiment, the second type of wear protection liner elements comprises tile plates removably arranged in a close pattern along at least one radially upper part adjacent the outer edge of the flange.
An advantage with this embodiment is that the lifetime of the flange is further improved.
A further advantage with this embodiment, and especially with the tile plates, is that this material is hard, but brittle, which is preferred features for the second type of wear protection liner elements. Thus, in the at least one radially upper part adjacent the outer edge of the flange, the flange is exposed to a lot of abrasive wear but low axial load, therefore it is preferably that the wear protection liner elements in this radially upper part of the flange is harder and each wear protection liner elements covering larger area.
By the disclosed design, where the tile plates are arranged in a close pattern facilitates provision of an improved protection against abrasive wear. Thus, when the tile plates are arranged in the close pattern, the flange is protected against wear to a greater extend compared to e.g. when the first type of wear protection liner elements being arranged as a mosaic pattern as discussed above. Usually, the at least one radially upper part is exposed to a lot of wear from e.g. material movements. Therefore, by this arrangement, the lifetime of the flange may be further improved.
In addition, by the term “removably arranged” is here meant that the tile plates may be removed and replaced in an easy way when they are worn out. Thus, instead of replacing the flange, it is possible to replace the tile plates instead. Preferably, the tile plates are arranged on the at least one radially upper part adjacent the outer edge of the flange by using a nut and bolt arrangement or screws, but adhesive or other similar means may also be used.
According to an embodiment, an elastic shim is arranged between the second type of wear protection liner elements and the flange.
An advantage with this embodiment is that the impact on the flange during skewing events may be reduced. Thus, introducing the elastic shim between the second type of wear protection liner elements and the flange will reduce the impact on the flange and an edge on the opposite roller body during skewing events that may occur during operation of the grinding roll in a grinding assembly. A further advantage with this embodiment is that a stable grinding roll during operation, and especially during skewing events, may be achieved. Preferably, the elastic shim is arranged between the second type of wear protection liner elements and the flange by using a nut and bolt arrangement or screws. However, other fastening or mounting arrangements may be possible as well.
According to an embodiment, the elastic shim comprises a spring assembly arranged between the second type of wear protection liner elements and the flange. The spring assembly may be attached between the second type of wear protection liner elements and the flange by installing the spring assembly from a second surface of the flange, through the flange, towards the second type of wear protection liner elements arranged on the first surface of the flange.
According to an embodiment, the elastic shim comprises a rubber mat, or a spring assembly.
According to an embodiment, the grinding roll having a flange attached to each of the first and second end of the roll body.
According to a second aspect of the disclosure, these and other objects are also achieved, in full or at least in part, by a grinding assembly for comminution of material, comprising two generally parallel grinding rolls arranged to rotate in opposite direction, towards each other, and separated by a gap, wherein the grinding assembly comprises at least one grinding rolls as disclosed with respect to the first aspect.
According to an embodiment, the grinding assembly comprises two grinding rolls, wherein each grinding roll having a flange attached to one of the first and second end of the roll body. Preferably, when the grinding rolls are arranged to rotate in opposite direction, towards each other, the flange on respective grinding roll should be positioned on opposite sides of the respective grinding roll.
According to another embodiment, the grinding assembly comprises two grinding rolls, wherein one of the two grinding rolls having two flanges attached to the first and second end of the roll body, and the other one having no flanges.
It should be noted that these embodiments are only examples and other arranged within the present disclosure is possible as well.
According to a third aspect of the disclosure, these and other objects are also achieved, in full or at least in part, by a flange ring segment arrangeable at a grinding roll along an edge thereof, the flange ring segment comprising a first surface and a second surface, the first surface forming a perpendicular continuing surface with a cylindrical outer surface of a grinding roll when arranged thereat, and the second surface forming a continuation of the an end of the grinding roll when arranged thereat; and the flange ring segment comprising wear protection liner elements on the first surface.
According to the disclosure the first surface comprising at least one radially lower part adjacent the cylindrical outer surface of the grinding roll when arranged thereat and at least one radially upper part adjacent an outer edge of the flange ring segment, wherein the at least one radially lower part comprises a first type of wear protection liner elements and the at least one radially upper part comprises a second type of wear protection liner elements, and wherein an average covering area of the second type of wear protection liner elements is larger than that of the first type of wear protection liner elements.
According to an embodiment, the first type of wear protection liner elements is arranged as a mosaic pattern on the at least one radially lower part of the flange ring segment.
According to an embodiment, the first type of wear protection liner elements comprises studs arranged in recesses provided in the at least one radially lower part of the flange ring segment.
According to an embodiment, the second type of wear protection liner elements comprises tile plates removably arranged in a close pattern along at least one radially upper part adjacent the outer edge of the flange ring segment.
According to an embodiment, an elastic shim is arranged between the second type of wear protection liner elements and the flange ring segment.
According to an embodiment, the elastic shim comprises a rubber mat or a spring assembly.
Other objectives, features, and advantages of the present disclosure will appear from the following detailed disclosure, from the attached claims, as well as from the drawings. It is noted that the disclosure relates to all possible combinations of features.
Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to “a/an/the [element, device, component, means, step, etc.]” are to be interpreted openly as referring to at least one instance of the element, device, component, means, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.
As used herein, the term “comprising”, and variations of that term are not intended to exclude other additives, components, integers, or steps.
The disclosure will be described in more detail with reference to the appended schematic drawings, which show an example of a presently preferred embodiment of the disclosure.
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.
The roll body 102 comprises a flange 112. The flange 112 is attached to the first end 108 of the roll body 102. The flange 112 has an outer edge 114. The outer edge 114 of the flange 112 extends radially past the cylindrical outer surface 104 of the roll body 102. The flange 112 may be attached to the roll body by bolt arrangement 210, see e.g.
The flange 112 has a first surface 116 forming a perpendicular continuing surface with the cylindrical outer surface 104 of the roll body 102. The flange 112 has a second surface 208 forming a continuation of the at least one of the first and the second end 108, 110 of the roll body 102 (see
The roll body 102 comprises a series of receiving bores that extends radially into the roll body 102 from the cylindrical outer surface 104. Each of the receiving bores receives a stud 126. Each of the studs 126 is formed from a material that is more durable than the roll body 102. The studs 126 may be replaced when worn to extend the life of the grinding roll 100. Preferably, the top end of the stud 126 extends past the cylindrical outer surface 104 such that material contacting the grinding roll 100 is first engaged by the top end of the stud 126. The crushed material forms a bed of material between the studs 126 to also enhance the durability of the cylindrical outer surface 104.
The roll body 102 comprises a plurality of edge wear protection bodies 128. The plurality of edge wear protection bodies 128 are arranged along the circumference of the roll body 102. The plurality of edge wear protection bodies 128 extends from the first end 108 or the second end 110 of the roll body 102 to the series of receiving bores.
The plurality of edge wear protection bodies 128 may preferably be arranged on an edge ring or edge segments 140 forming an edge ring.
However, it should be noted that the roll body 102 may be arranged without the series of the receiving bores and/or the edge wear protection bodies 128 such that the cylindrical outer surface 104 of the roll body 102 is smooth without any studs 126 and/or edge wear protection bodies 128.
The roll body 102 further comprises holes 132. The holes 132 may be configured to receive a bolt, screw, or the like in order to attach the flange 112 to the roll body 102. Preferably, there are holes 132 arranged along the periphery of the first end 108 and/or second end 110 of the roll body 102 in order to attach the flange 112 in a simple and secure way. Preferably, the holes 132 are pre-drilled holes in order to attach the flange 112 in an easy way.
In a similar way the roll body 102 may comprise an additional circle of holes configured to receive a bolt 142, screw or the like in order to attach the edge segments 140 or edge ring with edge wear protection bodies 128.
With reference to
A first straight line A has been drawn from the center of the first grinding roll 202 to the center of the second grinding roll 204.
A second straight line B has been drawn from the center of the first grinding roll 202 to and through a first point on the first grinding roll 202, at which first point an active engagement between the second grinding roll 204 and the material to be crushed is started. The angle formed between the first straight line A and the second straight line B is defined as a nip angle α.
A third straight line C has been drawn from the center of the first grinding roll 202 to and through a second point on the first grinding roll 204, at which second point an active crushing of the material between the first and second grinding rolls 202, 204 starts during operation of the grinding assembly 500.
The distance between the first point and the second point, as seen along the cylindrical outer surface 104 of the second grinding roll 204, defines a pre-compressed section 506 during operation of the grinding assembly 500. In the pre-compressed section 506, the outer edge 114 of the flange 112 attached to the first grinding roll 202 extends sufficient radially past the cylindrical outer surface 104 of the first grinding roll 202 to extend across the gap between the first and the second grinding rolls 202, 204 to a point on the second grinding roll 204, at which point the active engagement between the second grinding roll 204 and the material 502 to be crushed starts. In the pre-compressed section 506, the flanges 112 are configured to keep the material 502 between the grinding rolls 202, 204 such that the material 502 may be moved into a crushing section 508 between the grinding rolls 202, 204. In the pre-compressed section 506, there may be a lot of material movements when the material 502 forms the compact bed of material without any voids therein. Those movements may create a lot of abrasive wear on the at least one radially upper part 120 of the first surface 116 of the flanges 112. However, the axial load on the at least one radially upper part 120 of the first surface 116 of the flanges 112 is low in the pre-compressed section 506.
The distance between the second point and the first straight line, as seen along the cylindrical outer surface 104 of the second grinding roll 204, defines a crushing section 508 during the operation of the grinding assembly 500. In the crushing section 508, the at least one radially lower part 118 of the first surface 116 of the flanges 112 extends sufficient radially across the gap, and the at least one radially upper part 120 of the flange 112 are aligned with a peripheral outer section of the first and/or second end 108, 110 of the second grinding roll 204. In the crushing section 508, there is no voids in the material 502. As a consequence, there is no material movements in the crushing section 508 in relation to the at least one radially lower part 118 of the first surface 116 of the flanges 112 and hence, low or no abrasive wear on the at least one radially lower part 118 of the first surface 116 of the flanges 112. All material 502 present in this section is exposed to crushing forces.
A different between the pre-compressed section 506 and the crushing section 508 is that the material 502 in the pre-compression section moves in relation to the flanges 112, while the material 502 in the crushing section 508 moves with the at least one flange 112. On the other hand, the material 502 in the crushing section 508 do exert a significant axial force on the flanges 112.
Thus, in the pre-compressed section 506, the at least one radially upper part 120 and the at least one radially lower part 118 extends across the gap, wherein the at least one radially upper part 120 is exposed to a lot of abrasive wear due to the material movements in this section during operation of the grinding assembly 500. In the crushing section 508, the at least one radially lower part 118 extends across the gap, wherein the at least one radially lower part 118 is exposed to less or no abrasive wear but to a significant axial force during operation of the grinding assembly 500.
As the at least one radially lower part 118 and the at least one radially upper part 120 may be exposed to different type of wear, e.g. abrasive wear from the moving material and wear in form of axial forces, these should be covered with different wear protection liner elements in order to provide for an increased life of the flange 112.
Referring back to
Referring back to
Further to what have been discussed above, a second surface 208 of the flange 112 is illustrated. The flanges 112 are arranged with nut and bolt arrangement 210 for attaching the flange 112 to the roll body 102. It should be noted that other attaching arrangement may be used as well.
With reference to
As best illustrated in
Each flange segment 130 further comprises a section 304 arranged to be aligned with the first 108 and/or second end 110 of the roll body 102. This section comprises holes 302. The holes 302 may be aligned with corresponding holes in the roll body 102, which holes are arranged along the periphery of the first 108 and/or the second end 110 of the roll body 102. In this way the flange 112 may be attached in a simple and secure way. These holes 302 may be configured to receive a bolt, screw, or the like in order to attach the flange 112 to the roll body 102. Preferably, the holes 302 are pre-drilled holes in order to attach the flange 112 in an easy way. Obviously, other fastening means than bolting are conceivable.
Further to what have been discussed above,
With reference to
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.
For instance, the at least one radially upper and lower parts of the first surface of the flange may be of any suitable size and shape depending on the material to be comminution and on the type of grinding assembly that is used. The arrangement of the elastic shim may also vary depending on the grinding assembly.
