EP3405286B1 - Wear-resistant element for a comminuting device - Google Patents

Description

The invention relates to a grinding and / or crushing unit with a wear protection element for partial insertion into a recess on the surface of a wear surface of the grinding and / or crushing unit.

In the case of comminution devices, such as grinding rollers, which are used in particular in the comminution of material beds of, for example, hard ore, the surface of a wear surface, such as the grinding roller surface, is subject to high wear during operation of the comminution device. From the US 6 290 008 B1 a wear protection element for drill bits for rock drills with a coating of a polycrystalline diamond layer is known. The EP 2 940 169 A1 discloses a breaking tool for a crusher having a coating of a composite material. To counteract wear, it is, for example, from the DE 2006 010 042 A1 known to apply additional wear protection elements to the surface of the grinding roller. With a certain degree of wear, it is necessary to replace the wear protection elements of the grinding roller in order to guarantee efficient grinding. The replacement of the wear protection elements requires, for example, long downtimes of the roller mill and high maintenance costs.

It is therefore the object of the present invention to provide a grinding and / or crushing unit with a wear protection element which has high wear resistance in order to increase the maintenance intervals for replacing the wear protection elements.

This object is achieved by a grinding and / or crushing unit with the features of the independent device claim 1. Advantageous developments result from the dependent claims.

A wear protection element for partial insertion into a recess on the surface of a wear surface of a comminution device, in particular a grinding roller of a roller mill, comprises, according to a first aspect, particles of a highly wear-resistant material embedded in a matrix material. The particles show in particular a higher wear resistance than the matrix material in which they are embedded. The term embedded is to be understood as meaning that the highly wear-resistant particles are at least partially enclosed by the matrix material. The particles are preferably embedded in the matrix in such a way that an integral connection is formed between the matrix material and the particles. In particular, the particles have a size of 2 µm to 5 mm, preferably 5 µm to 2 mm.

The crushing device is, for example, a roller mill, a roller crusher, a cone crusher, a hammer mill or a vertical roller mill, the wear surface in particular the surface of a grinding roller, a crushing cone, the hammer tools and the surface of the grinding track, which is exposed to high wear during operation of the crushing device a hammer mill or the surface of the rollers and the grinding table of a vertical roller mill.

The wear protection element is, for example, cylindrical or has a square cross section. In particular, one end of the wear protection elements is designed in such a way that it can be fastened to the surface of the wear surface, in particular in a recess in the surface of the wear surface. In particular, the wear protection element is plate-shaped. This is particularly advantageous when such a wear protection element is used on, for example, a grinding track of a hammer mill or a vertical roller mill.

The wear resistance of the wear protection element is determined in particular by the distribution density of the particles within the matrix material. Particles embedded in a matrix material therefore enable simple production of wear protection elements of different wear resistance, the distribution density of the particles within the matrix material being varied for different wear protection elements so that wear protection elements that are exposed to greater wear, for example on the front edges of the grinding roller, have a higher distribution density Has particles.

The matrix material comprises tungsten carbide. Tungsten carbide has a high wear resistance and is very suitable as a matrix material for embedding highly wear-resistant particles, since the high wear resistance prevents the diamond particles from being washed out.

According to a further embodiment, the highly wear-resistant material of the particles comprises diamond, ceramic or titanium. The aforementioned materials have a very high wear resistance and, in particular embedded in a tungsten carbide matrix, increase the wear resistance and thus the service life of a wear protection element of a roller mill considerably.

According to a further embodiment, the particles of highly wear-resistant material are uniformly distributed in the matrix material or are concentrated within the matrix material at a selected position. In particular, the proportion of particles within the matrix material is a concentration of 20% to 80%, preferably 35% -65%. A uniform distribution of the particles within the matrix material offers the advantage of uniform wear of the wear protection element during operation of the comminution device, with an increased concentration of particles in a certain area within the matrix material offering the advantage of a local increase in the wear resistance of the wear protection element. In particular, this makes it possible to provide areas that are exposed to particularly heavy wear with a higher distribution density of the particles.

According to a further embodiment, the wear protection element has a core area and a jacket area at least partially surrounding the core area, the particles made of the highly wear-resistant material being arranged exclusively in the core area. The jacket area is preferably tubular so that the core area extends over the entire length of the wear protection element. The core area is preferably cylindrical, the end faces of the wear protection element having the jacket area and the core area.

To adapt the wear protection elements into a recess in the surface of the wear surface, it is often necessary to process the surfaces of the wear protection elements, for example by grinding. A jacket area in which no highly wear-resistant particles are arranged enables the wear protection element to be easily machined.

According to a further embodiment, the jacket area is formed from tungsten carbide or a steel alloy.

According to a further embodiment, the jacket area and the core area are materially connected to one another, in particular sintered. This increases the wear resistance and breaking strength of the wear protection element.

According to a further embodiment, the particles made of the highly wear-resistant material are arranged in the core area in such a way that the particle distribution density increases in the direction of the cladding area. This enables the particles to be concentrated in the edge area of the core area, with a smaller number or, for example, no particles being arranged in the inner area of the core area. This results in a cost reduction in the production costs of the wear protection elements, since the number of particles in the wear protection element is reduced overall.

According to a further embodiment, the wear protection element has a fastening area which can be connected to the recess in the surface of the wear surface and a wear area which protrudes at least partially from the surface of the wear surface. The fastening area is arranged in the position of the wear protection element arranged in the recess in the wear surface, in particular radially inward of the wear area, and is connected to the grinding roller. The fastening area is designed in particular in such a way that it does not protrude at all or only very slightly from the recess in the wear surface, so that the wear protection element can be replaced in the event of wear up to the length of the Fastening area is necessary. In particular, the particle distribution within the wear area increases in the direction of the surface of the wear area, in particular the surface of the wear protection element.

According to a further embodiment, only the wear area comprises the particles of highly wear-resistant material embedded in the matrix material. This enables a reduction in the production costs of the wear protection element, since the fastening area does not have any particles.

According to a further embodiment, the wear protection element has an end cutout, in particular a bore. The recess is preferably formed in the fastening area on the end face facing the wear surface of the shredding device. The recess has, for example, a round or a square cross section and is arranged coaxially to the wear protection element. The recess is arranged in the end face of the wear protection element, in particular the end face facing the wear surface. Such a recess enables material to be saved and thus a considerable reduction in the cost of the wear protection element.

According to a further embodiment, the fastening area comprises a material that has a lower wear resistance than the material of the wear area. This also results in a cost reduction for the wear protection element.

According to a further embodiment, the fastening area is sleeve-shaped and the wear area is arranged within the sleeve-shaped area of the fastening area. The sleeve-shaped design of the fastening area enables a particularly simple production of the fastening area. The wear area preferably has a particle distribution density which increases in the direction of the surface of the wear area, so that the greatest number of highly wear-resistant particles is arranged on the surface. In particular, the particle distribution density increases in the direction of the outer edge area of the wear protection element that protrudes from the wear surface.

According to a further embodiment, the fastening area and the wear area are materially connected to one another, in particular glued or soldered.

The fastening area comprises, for example, less than 45%, preferably less than 30%, most preferably less than 20% of the wear protection element.

The wear area extends, for example at the level of the wear protection element, at least partially beyond the fastening area.

According to a further embodiment, the fastening area of the wear protection element is materially connected to the wear surface of the comminution device, in particular welded, glued or soldered.

The advantages described with reference to the wear protection element also apply to a corresponding grinding and / or crushing unit with such a wear protection element.

Description of the drawings

• Fig. 1 zeigt eine schematische Darstellung einer Walzenmühle in einer Frontansicht gemäß einem Ausführungsbeispiel.
• Fig. 2 zeigt eine schematische Darstellung einer Mahlwalze der Walzenmühle gemäß Fig. 1.
• Fig. 3-15 zeigt schematische Darstellungen verschiedener Ausführungsbeispiele von Verschleißschutzelementen in einer Querschnittsansicht.

The invention is explained in more detail below on the basis of several exemplary embodiments with reference to the accompanying figures.

• Fig. 1 shows a schematic representation of a roller mill in a front view according to an embodiment.
• Fig. 2 shows a schematic representation of a grinding roller of the roller mill according to FIG Fig. 1 .
• Fig. 3-15 shows schematic representations of various exemplary embodiments of wear protection elements in a cross-sectional view.

In Fig. 1 a roller mill 10 is shown schematically. The roller mill 10 comprises two grinding rollers 12, 14, shown schematically as circles, which have the same diameter and are arranged next to one another. Between the grinding rollers 12, 14 there is a grinding gap which, for example, can be adjusted in size.

When the roller mill is in operation, the grinding rollers 12, 14 rotate in the opposite direction to one another in the direction of rotation shown by the arrows, with ground material running through the grinding gap in the direction of fall and being ground.

Fig. 2 shows an end region of a grinding roller 12, which has a roller base body 15 to which wear protection elements 16 are attached. The wear protection elements 16 are mounted in the outer periphery of the surface of the grinding roller. By way of example, the wear protection elements 16, which are spaced apart from one another and arranged next to one another, have Fig. 2 a circular cross-section. It is also conceivable that the wear protection elements 16 vary over the surface of the grinding roller in terms of size, number, cross-sectional shape and the arrangement relative to one another in order to compensate for local differences in wear during operation of the grinding roller 12, 14, for example.

Furthermore, the grinding roller 12 has wear protection corner elements 17 attached to its end, which for example have a rectangular cross section and are arranged in a row next to one another in such a way that they form a ring over the circumference of the grinding roller 12. There are also other cross-sectional shapes of the wear protection corner elements 17 conceivable, which are from the in Fig. 2 shown cross-sectional shape. An arrangement of the wear protection corner elements 17 at a distance from one another is also possible. In Fig. 2 only the left end of the grinding roller 12 is shown by way of example, the right end, not shown, advantageously being identical in structure.

Fig. 3 shows a wear protection element 16a, which is in a recess 32 in the roller base body 15 of a grinding roller 12, 14 according to Figs. 1 and 2 is arranged. The wear protection element has a fastening area 24 and a wear area 22, the fastening area being arranged in the recess 32 on the surface of the grinding roller 12, 14 and being connected to the basic roller body 15 of the grinding roller 12, 14. For example, the wear protection element 16a on the fastening area 24 is integrally connected to the recess in the surface of the roller base body 15 of the grinding roller 12, 14, in particular welded, soldered or glued or positively connected, in particular screwed or wedged. The wear area 22 of the wear protection element 16a is arranged at least partially outside the recess 32 in the roller base body 15, so that it protrudes from the roller base body 15 in the radial direction of the grinding roller (not shown). In the exemplary embodiment shown, the fastening area comprises approximately one third of the entire wear protection element 16a, the wear area approximately encompassing the other two thirds.

The wear protection element 16a has a matrix material 18 in which a plurality of particles 20 are arranged. The particles 20 are arranged distributed uniformly in the matrix material 18. The wear area 22 and the fastening area 24 have the same particle distribution in the matrix material. The particles 20 are in particular a highly wear-resistant material that includes, for example, diamond, ceramic or titanium. The matrix material 18 comprises, for example, tungsten carbide. The particles 20 are in particular materially connected to the matrix material 18, for example by sintering.

During operation of the roller mill, the wear protection elements 16a are exposed to a high level of wear, in particular the wear area 22 of the wear protection elements 16a protruding from the surface of the grinding roller 12, 14 wears. The highly wear-resistant particles 20 in the matrix material 18 considerably reduce the wear of the wear protection elements 16a, the number of particles 20, in particular the distribution density of the particles 20, in the matrix material 18 increasing the wear resistance of the wear protection element 16a.

Fig. 4 shows a further exemplary embodiment of a wear protection element 16, the roller base 15 with the recess 32 in which the wear protection element 16b is arranged not being shown. This in Fig. 4 The wear protection element 16b shown essentially corresponds to that in FIG Fig. 3 shown wear protection element 16a and has the reference Fig. 3 described fastening area 24 and the wear area 22, which corresponds to the Fig. 3 are arranged. In contrast to the Fig. 3 instructs the Fig. 4 a core area 28 and a jacket area 26 circumferentially surrounding the core area 28. The core area 28 extends in the longitudinal direction of the wear protection element 16b from one end of the wear protection element 16b to the other end of the wear protection element 16b. The jacket area 26 is essentially tubular and encloses the circumference of the core area 28. The particles 20 are in the exemplary embodiment from FIG Fig. 4 arranged exclusively in the core area 28 of the wear protection element 16b and evenly distributed within the core area 28. The jacket region 26 does not have any particles 20. The jacket region 26 comprises, for example, the matrix material 18 tungsten carbide or, for example, a steel alloy.

Fig. 5 shows a further embodiment of a wear protection element 16c, which is essentially the wear protection element 16b of Fig. 4 corresponds to the The difference is that wear protection element 16c does not have any particles 20 in fastening area 24. The particles 20 are arranged exclusively in the core area 28 of the wear area 22 of the wear protection element 16c. The particles 20 are arranged distributed in the core area 28 of the wear area 22 in such a way that the density of the particle distribution increases in the direction of the cladding area 26, so that the highest particle distribution density is arranged at the boundary area between the core area 28 and the cladding area 26. The particle distribution density also increases in the longitudinal direction of the wear protection element 16c, in particular outwards in the radial direction of the grinding roller.

Fig. 6 shows a wear protection element 16d, which is essentially the wear protection element 16a of Fig. 3 corresponds with the difference that the wear protection element 16d has a recess 30 in its fastening area 24. The recess 30 is attached to the end face in the fastening area 24 and is, for example, cylindrical or conical and extends over the entire fastening area and is particularly coaxial with the wear protection element 16d. The recess 30 is used, for example, to fasten the wear protection element 16d in the recess 32 in the roll surface. Furthermore, the recess results in a considerable saving in material.

Fig. 7 shows a wear protection element 16e, which is essentially the wear protection element 16d of Fig. 6 with the difference that the wear protection element 16e corresponds to a jacket region 26 and a core region 28 according to FIG Fig. 4 has, wherein the fastening area has no particles 20.

Fig. 8 shows a wear protection element 16f, which essentially corresponds to the wear protection element 16a of Fig. 3 The fastening area 24 is made of a different material than the wear area 22. The fastening area 24 is made, for example, of a softer, in particular less wear-resistant material than the wear area. For example, the fastening area comprises a steel. The fastening area 24 and the wear area 22 are in particular materially connected to one another, for example glued, welded or soldered. It is also conceivable that To design wear protection element 16f in the form of a plate, the fastening area and the wear area being in the form of a plate. A plate-shaped design of the wear protection element is particularly suitable when used for wear protection of a grinding track.

Fig. 9 shows a wear protection element 16g, which essentially corresponds to the wear protection element 16f of Fig. 8 corresponds, the fastening area 24 of the wear protection element 16g having an inwardly pointing curvature at the end facing the wear protection area 22. This curvature is used to position the wear area 22 on the fastening area 24.

Fig. 10 shows a wear protection element 16h, which is essentially the wear protection element 16f of Fig. 8 corresponds to, the wear area 22 having a core area 28 and a jacket area 26 surrounding the core area 28 according to FIG FIGS. 4 and 7 having.

Fig. 11 shows a wear protection element 16i, which is essentially the wear protection element 16f of Fig. 8 corresponds to, the wear area 22 having a core area 28 and a jacket area 26 surrounding the core area 28 according to FIG Fig. 5 having.

Fig. 12 shows a wear protection element 16j, which has an essentially sleeve-shaped fastening area 24, this extending over the entire length of the wear protection element 16j and the wear area 22 being arranged within the sleeve-shaped fastening area 24. The sleeve-shaped fastening area 24 is formed, for example, from a softer, less wear-resistant material than the wear area 22. The material of the wear area 22 corresponds to that with reference to FIG Fig. 3, 6 , 8 and 9 described material.

Fig. 13 shows a wear protection element 16k, which is essentially the wear protection element 16f of Fig. 8 corresponds, the area of the fastening area 24 of the wear protection element 16k facing the wear area 22 has a recess which interacts with a projection in the area of the wear protection area 22 facing the fastening area 24. Such a recess in the fastening area is used in particular to position the wear area on the fastening area, the wear area being centered relative to the fastening area 24. The recess is, for example, cylindrical and centered.

Fig. 14 shows a wear protection element 16l, which is essentially the wear protection element 16j of Fig. 12 corresponds, with a recess 30 according to FIG Figures 6 and 7 is arranged.

Fig. 15 shows a wear protection element 16m, which is essentially the wear protection element 16j of Fig. 12 corresponds, with the wear area 22 extending beyond the sleeve-shaped fastening area 24.

List of reference symbols

10

Roller mill

12th

Grinding roller

14th

Grinding roller

15th

Roller body

16

Wear protection element

17th

Wear protection corner element

18th

Matrix material

20th

Particles

22nd

Wear area

24

Attachment area

26th

Mantle area

28

Core area

30th

Recess

32

Recess

Claims (14)

1. Grinding and/or crushing assembly (10) having a wear-resistant element (16a-m), wherein the wear-resistant element (16a-m) is mounted at least partially in a recess (32) in the wear area of the grinding and/or crushing assembly (10), wherein
   the wear-resistant element (16) comprises particles (20) made of a highly wear-resistant material which are embedded in a matrix material (18),
   characterized in that the matrix material (18) comprises tungsten carbide.
2. Grinding and/or crushing assembly (10) according to Claim 1, wherein the highly wear-resistant material of the particles (20) comprises diamond, ceramic or titanium.
3. Grinding and/or crushing assembly (10) according to either of the preceding claims, wherein the particles (20) made of highly wear-resistant material are distributed uniformly in the matrix material (18) or are concentrated at a selected position within the matrix material (18).
4. Grinding and/or crushing assembly (10) according to one of the preceding claims, wherein the wear-resistant element (16a-m) comprises a core region (28) and a shell region (26) which at least partially surrounds the core region (28), wherein the particles (20) made of the highly wear-resistant material are arranged exclusively in the core region (28).
5. Grinding and/or crushing assembly (10) according to Claim 4, wherein the shell region (26) is formed from tungsten carbide or a steel alloy.
6. Grinding and/or crushing assembly (10) according to Claim 4 or 5, wherein the shell region (26) and the core region (28) are bonded, in particular sintered, to one another substance-to-substance.
7. Grinding and/or crushing assembly (10) according to one of Claims 4 - 6, wherein the particles (20) made of the highly wear-resistant material are arranged in the core region (28) in such a manner that the particle distribution density rises in the direction of the shell region (26).
8. Grinding and/or crushing assembly (10) according to one of the preceding claims, wherein the wear-resistant element (16) comprises a fastening region (24), which can be connected to the recess (32) in the surface of the wear area of the comminuting device, and a wear region (22), which protrudes at least partially out of the surface of the wear area of the grinding and/or crushing assembly (10).
9. Grinding and/or crushing assembly (10) according to Claim 8, wherein exclusively the wear region (22) comprises the particles (20) made of highly wear-resistant material which are embedded in the matrix material (18).
10. Grinding and/or crushing assembly (10) according to Claim 8 or 9, wherein the wear-resistant element comprises a cutout (30) on the end face, in particular a borehole.
11. Grinding and/or crushing assembly (10) according to one of Claims 8 - 10, wherein the fastening region (24) comprises a material which has a lower wear resistance than the material of the wear region (22).
12. Grinding and/or crushing assembly (10) according to one of Claims 8 - 11, wherein the fastening region (24) has a sleeve-shaped form and the wear region (22) is arranged within the sleeve-shaped region of the fastening region (24).
13. Grinding and/or crushing assembly (10) according to one of Claims 8 to 12, wherein the fastening region (24) and the wear region (22) are bonded, in particular adhesively bonded or soldered, to one another substance-to-substance.
14. Grinding and/or crushing assembly (10) according to one of the preceding claims, wherein the fastening region (24) of the wear-resistant element (16a-m) is bonded, in particular welded, adhesively bonded or soldered, to the wear area (12, 14) of the grinding and/or crushing assembly (10) substance-to-substance.

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