EP2825315B1 - Roller for a roller press - Google Patents

Description

The invention relates to a press roll for a roll press, in particular for the comminution of highly abrasive substances, with a roll body which (for the wear protection in the edge regions) on one or both roll edges a plurality of circumferentially spaced and spaced apart in the tangential direction or circumferential direction pocket-like recesses, which are each formed laterally and open at the top, wherein in the individual pocket-like recesses only one hard body is used as an exchangeable edge protection element.

A roll press usually has two press rolls. The roll press is used in particular to comminution and in particular high-pressure crushing of coarse mineral feed materials such. As ores, cement clinker, slag, kimberlite, coal or ceramic base materials. Such a roller press is also referred to as a good bed roller mill. However, the invention also includes roller presses for the compaction or briquetting of material.

In the processing and in particular comminution of brittle, granular material with such a roller press high forces occur and the roll surfaces are heavily stressed, so that the wear protection of the roll surfaces in practice is of particular importance. Thus, it is known in practice to use for the wear protection of the roll surface cylindrical carbide pins or stud bolts, which are "hedgehog-like" stored in corresponding blind holes of the roller body and together with the pressed-in regrind an autogenous wear protection layer (see. EP 0 516 952 A1 ). In the area of the roll edges, however, such a wear protection is usually unsatisfactory, since the risk of Breaking the pins in the edge areas is large. For this reason, special measures have already been proposed for edge protection and for wear protection in the edge regions of the roll.

So is out of the EP 0 516 952 A1 a generic press roll known in which not only cylindrical hard metal pins are introduced for wear protection in the roll body, but in which pocket-like recesses are provided on the roll edges, which are each formed laterally and openly above, in which pocket-like recesses plate-shaped, wear-resistant material pieces embedded are. The distance between these edge protection elements along the circumferential direction of the roller corresponds approximately to the distance between the stud bolts embedded in the other roller areas. Press rollers with wear protection elements in the edge areas are also available in DE 10 2007 007 276 A1 and DE 20 2010 013 735 U1 disclosed. The achieved in this way wear protection in the edge areas, however, is unsatisfactory.

For this reason, alternative edge protection concepts have been proposed in which replaceable edge protection elements are used in lateral and open top, circumferential annular shoulders.

That's how it describes EP 1 502 650 B1 a press roll with arranged on the roll edges, circumferential recesses in the form of annular shoulders, wherein in each of these recesses a plurality of wear protection elements are arranged in the circumferential direction one behind the other. In this way, the wear protection elements made of hard metal form a quasi-closed ring, which should offer a high wear protection. The wear protection elements can be attached by gluing, stapling or soldering directly in the circumferential ring shoulders. In general, the wear protection elements are mounted in the circumferential recesses close together, so that also no autogenous wear protection between the elements is formed.

The same applies to one from the EP 1 684 907 B1 Known press roll or grinding roller for the crushing granular material, in which for the edge protection a plurality of hard bodies are arranged on the roll end edges in a circumferential annular shoulder of the roll shell, said hard bodies protrude both axially from the end face and radially from the surface of the roll shell.

An alternative wear protection concept is used in the EP 0 659 108 B1 described. The wear layer of the press roll has substantially planar zones of a highly wear-resistant material, the z. B. tiles or tiles can be formed. The spaces between the highly wear-resistant zones are filled with a material of other wear resistance. The tiles or tiles can z. B. made of a metal matrix composite material by hot isostatic pressing. These prefabricated hard bodies are then permanently attached to the base body together with the interspace material by hot isostatic pressing.

Starting from the above-described prior art, the invention, the technical problem underlying a press roll for a roller press to create, which is characterized by a particularly resistant, yet replaceable wear protection on the roll edges.

To solve this problem, the invention teaches in a generic pressure roller of the type described above with individual pocket-like recesses at the roll edges, that the length of the pocket-like recesses and the length of the edge protection elements used in the circumferential direction in the region of the outer upper edges of the edge protection elements is more than five times the distance between two immediately adjacent recesses in the region of the outer upper edges of the edge protection elements.

The invention is initially based on the recognition that it is fundamentally advantageous to equip the press roll on the roll edges with exchangeable and consequently detachable edge protection elements. Detachable means within the scope of the invention that these edge protection elements can be removed from the recesses without destruction for the purpose of replacement. In this respect, in addition to screw and positive connections and connections detected by gluing or soldering, as this z. B. can be solved by heating again. The releasable edge protection elements according to the invention, however, are now not arranged in circumferential grooves or annular shoulders, but in individual pocket-like recesses, wherein in each individual pocket-like recess in each case only a hard body is used as an exchangeable edge protection element releasably. Compared with the known solutions with circumferential annular shoulders, the solution according to the invention has the advantage that the individual edge protection elements, despite the very high pressing forces do not touch and therefore also do not abut each other or can be pressed against each other. Damage to the individual edge protection elements is thus avoided, and in particular damage due to breakage, which in principle is to be feared with brittle hard materials. The arrangement of the edge protection elements in individual, locally limited pockets moreover has the advantage that the edge protection elements are not only supported on a step-like shoulder on the underside and on the inside, but also laterally. Because the design of the roll edge with individual, locally limited pockets has the consequence that the individual recesses are delimited from each other by "dividers", so that the edge protection elements are supported tangentially by these dividers. The high pressure forces that occur can be well diverted into the body. Finally, the solution according to the invention over the known arrangements with circumferential annular shoulders has the advantage that can form an autogenous wear protection in the region of the partitions and thus in the area between the individual pockets and edge protection elements, which protects the edges of the wear protection elements used to a particular extent. Thus, the autogenous wear protection can build up not only in the remaining roller areas, but also in the edge area and between the individual edge protection elements. This has the consequence that a auskolkender wear in these zones is avoided. In the known solutions with circumferential annular shoulders, there is the problem that scumming, in particular in the region of the joints of the individual segments, can lead to the material being pressed into the resulting depressions. As a result, bending is applied to the elements, which can then lead to fracture of the brittle elements, in particular with edge protection elements made of hard metal.

The pocket-like recesses are - as described - each side and top open. Laterally open means in the context of the invention based on the roller frontally open, that is open on the side facing away from the roll center in the axial direction. Open at the top means within the scope of the invention open on the side facing away from the roll axis in the radial direction. In detail, it will be discussed in the figure description.

Although the present invention - in departure from the known concepts with circumferential annular shoulders - is used with individual laterally and upwardly open pockets, the press roll according to the invention is characterized by a reliable edge protection over the entire peripheral region of the press roll out. Because the (tangential) length of the pocket-like recesses and thus the length of the edge protection elements used in the circumferential direction is (significantly) greater than the (tangential) distance between two immediately adjacent recesses and consequently significantly greater than the thickness of the arranged between the recesses separating webs. According to the invention, the length of the recesses and the length of the edge protection elements is more than five times, preferably more than ten times the distance between the individual pockets. The relatively small distance between the recesses compared with the length of the recesses also has the advantage that an autogenous wear protection can form perfectly even in the edge region. Nevertheless, the dividers between the recesses provide sufficient stability to achieve the advantages already described. For this purpose, the invention proposes in a preferred embodiment that the (tangential) distance between two immediately adjacent recesses is more than 3 mm, preferably more than 4 mm.

The edge protection elements arranged in the individual pockets can have geometrically very different shapes. Edge protection elements are preferably used, which are square, for example rectangular in plan view of the roll surface. It is within the scope of the invention that the edge protection elements in a side view of the roller angular, z. B. are rectangular, so that the edge protection elements z. B. may have the shape of a cuboid. Alternatively, however, edge protection elements of other geometry are also covered by the invention, which may also have a non-cornered shape, particularly in plan view.

Particularly preferred edge protection elements are used, whose shape differs from that of a cuboid. Thus, the invention preferably proposes that the side recesses in the side view at least partially curved wall surfaces and have the edge protection elements at least partially adapted to the curved wall surface, curved outer contour. Thus, the (partially) curved wall surface of the recess and the (partially) curved outer contour in cross-section circular arc or alternatively also be formed parabolic in cross section. In any case, the already described lateral support of the edge protection elements and thus the derivation of the compressive forces in the body can thereby optimize. Incidentally, such pockets with curved wall or floor areas can be particularly easy to introduce into the body, z. B. by milling.

The advantages of the invention can be achieved with edge protection elements made of various materials. Thus, it is within the scope of the invention that the edge protection elements used detachably in the pocket-like recesses made of hard metal or hard metal similar materials, eg. As cermets exist. However, edge protection elements of metal matrix composite material (MMC) may preferably be used within the scope of the invention. These edge protection elements made of MMC have the advantage over tungsten carbides that they can be designed less brittle by suitable choice of matrix materials, the proportion of which is much higher in comparison to carbide in MMC, and thus are less sensitive to bending. By the selected composition of the material, moreover, it is also possible to "adjust" the wear. In practice, there has hitherto been the problem that the pressure in the region of the roll edges is generally lower than in the region of the roll center. As a result, the edge protection elements wear out more slowly, causing the rollers to roll in the center of the roll become "thinner" or receive a "concave" geometry. In extreme cases, this can go so far that the material in the center of the roller does not undergo sufficient comminution. These disadvantages can be z. B. by the use of suitable edge protection elements made of metal matrix composite materials with tailored to the particular application wear characteristics and rates. Metal matrix composite means a material in which hard particles are bound into a continuous metallic matrix, wherein the hard particles are arranged by the continuous metallic matrix separated from each other within the composite material. Such edge protection elements made of a metal matrix composite material are preferably produced by sintering and / or hot isostatic pressing. In the finished material, the non-metallic hard particles are distributed and each surrounded by the metallic material of the metal matrix. Among the hard metals, the metal matrix composite materials therefore differ, inter alia, by the relatively low proportion of hard particles. Incidentally, the hard particles of the metal matrix composite materials are significantly larger than the hard particles of hard metals. Preferably, in the context of the invention, a metal matrix composite material is used in which hard particles of a size of more than 20 microns, z. B. more than 40 microns (preferably more than 60 microns) and a volume fraction of less than 50% (preferably less than 40%) are used, which are embedded (discontinuously) in a (contiguous) metallic matrix. In each case, the volume fractions in the (pressed) hard body are meant.

Basically, it is within the scope of the invention that the edge protection elements are designed as substantially homogeneous solid body, z. As carbide, cermet or MMC. In an alternative, preferred embodiment, however, the edge protection elements may have a composite structure and in each case a carrier element with one or arranged thereon Wear layer, wherein the carrier element consists of a ductile material with lower hardness than the wear layer. This embodiment has the advantage that the carrier element made of a good material to be processed, for. As steel, can be made, which in particular allows optimal attachment of the edge protection element on the roll body. The wear layer itself then forms the wear protection. The wear layer of the edge protection element can, for. B. hard metal or a carbide-like material, eg. As cermet, or - as already described - from a metal matrix composite material (MMC). This wear layer is firmly connected in the course of the production of the edge protection elements with the carrier element, for. B. by sintering and / or hot isostatic pressing (HIP).

The applied to the carrier element wear layer can cover the entire surface of the support element and thus form the entire surface of the edge protection element. Alternatively, however, the wear layer may cover only a portion of the support element. So there is z. B. the ability to incorporate a recess in the support element, in which the wear layer is then integrated in the sense of a wear insert.

The edge protection elements are inventively releasably attached to the roller body, so that the edge protection elements are basically interchangeable. Such attachment succeeds z. B. by a screw. For this purpose, the edge protection elements suitable openings, z. B. holes, through which corresponding fasteners, z. As screws, can be introduced into the roll body. Such a configuration is particularly suitable when the edge protection element is a carrier element made of a ductile material, for. B. steel. Alternatively, it is also within the scope of the invention, the edge protection elements by gluing or soldering (releasably) in the pockets to attach. Alternatively or additionally, in addition, a positive connection of the edge protection elements in the pockets can be realized, namely z. B. by a "dovetail connection". For this purpose, the edge protection elements can be equipped with (for example dovetail-like) form-fitting webs which engage positively in corresponding negative forms in the pockets.

The separating webs arranged between the individual recesses or pockets can have a constant thickness in the axial direction. Optionally, however, this thickness can also vary over the width of the recess. Thus, the thickness of the separating web can increase or decrease from the roll edge in the direction of the roll center.

In order to further optimize the fastening of the edge protection elements in the pockets and / or the introduction of the pressing forces into the roll body, the recesses and the edge protection elements can each have a cross-section widening at least in the direction of the roll center. Consequently, the cross-section can widen or extend in regions from the direction of the roll end side in the direction of the roll center, so that the (inner) surface of the edge protection elements, which in each case faces the center of the roll in the axial direction, is larger than the (outer) surface facing the roller end face. The contour of the recesses or pockets is carried out according to "negative". In this way, the edge protection element itself are positively connected at their outer contours with the roller, so that they are secured in the course of assembly against falling out.

The invention relates not only to the described press roll itself, but in a preferred development also a roll press with two such press rolls.

Incidentally, the press roll may be formed as a solid roll, that is, the roll body is formed as a solid body. Alternatively, the roller body can also have a (cylindrical) base body and a bandage arranged thereon, so that the wear protection is then mounted on / on this bandage.

The pocket-like recesses can in the body, ie in the solid body or in the bandage, z. B. be machined by machining to form the partitions.

Fig. 1

eine perspektivische Ansicht auf eine erfindungsgemäße Press-walze in einer ersten Ausführungsform (Ausschnitt),

Fig. 2

den Gegenstand nach Fig. 1 in einer abgewandelten zweiten Ausführungsform,

Fig. 3

den Gegenstand nach Fig. 1 in einer abgewandelten dritten Ausführungsform und

Fig. 4

einen Querschnitt durch eine abgewandelte Ausführungsform der Erfindung,

Fig. 5

eine weitere Option der Erfindung.

In the following the invention will be explained in more detail with reference to drawings showing merely exemplary embodiments. Show it

Fig. 1

a perspective view of a press roller according to the invention in a first embodiment (detail),

Fig. 2

the object after Fig. 1 in a modified second embodiment,

Fig. 3

the object after Fig. 1 in a modified third embodiment and

Fig. 4

a cross section through a modified embodiment of the invention,

Fig. 5

another option of the invention.

In the figures, in each case a press roll 1 for a roll press, in particular for the high-pressure crushing of brittle, mineral feed material is shown. The roller press usually consists of two press rollers 1, of which in the figures, however, only one is shown in the cutout. Such a press roller 1 can - as shown in the figures - be formed as a solid roller, wherein the roller body 2 is then formed as a solid body. Alternatively, however, the roller body can also have a base body and a bandage surrounding it. This is not shown in the figures.

In any case, such a press roller is equipped with a suitable wear protection, which can be configured in various ways. The illustrations in the figures are limited to the wear protection measures in the region of the (frontal) roll edges.

For wear protection in the area of the roll edges, the roll body 2 has at one or both roll edges a multiplicity of pocket-like recesses 3 distributed over the circumference and spaced apart in the circumferential direction or tangential direction T. The individual pocket-like recesses 3 are separated from one another in the circumferential direction T by separating webs 4. The recesses are open both laterally and above. In each pocket-like recesses 3, a single hard body is used as an exchangeable edge protection element 5 releasably. The figures show the press roll 1 while in a partially assembled state, that is, some recesses 3 are shown for better understanding without inserted edge protection element.

In Fig. 1 Incidentally, the circumferential direction or the tangential direction T, the axial direction A and the radial direction R are shown. As already explained, the individual pocket-like recesses 3 are each open both laterally and upwardly. Open at the side, therefore, means open on the face side, ie on the side facing away from the roll center in the axial direction A. Open top means on the side facing away from the roll axis in the radial direction R side.

In the embodiment according to the invention is thus dispensed with the known circumferential annular shoulders on the roll edges. Rather, individual pocket-like recesses and consequently receiving pockets 3 are proposed, in each of which only a single edge protection element 5 is inserted. The length L of the pocket-like recesses and also the length I of the edge protection elements 5 used according to the invention is more than five times greater than the distance a between two immediately adjacent recesses 3. The lengths L, I and the distance a refer to the circumferential direction T of the roller , in the area of the outer, upper edges of the edge protection elements. The distance a between the individual pockets 3 thus corresponds to the thickness of the webs 4 arranged between the recesses 3 and consequently also between the edge protection elements 5, which are part of the roller body 2. The pocket-like recesses 3 are consequently in the roll body 2 z. B. introduced by machining.

The inventive design with individual pockets 3 causes the individual edge protection elements 5, which are designed as hard body, not abutting and despite the large forces occurring can not be pressed against each other, so that damage to the edge protection elements can be avoided. Furthermore, the pressure forces that occur can be introduced into the roller body 2 without any problem by means of this embodiment. This applies in particular for the embodiment shown in the figures, in which the lateral recesses 3 in the side view have a curved wall portion or bottom portion 3a and the edge protection elements 5 have a curved outer contour 5a, wherein the curved outer contour 5a is adapted to the curved wall portion 3a. In the embodiment of the Fig. 1 to 3 Both the curved wall portion 3a and the curved outer contour 5a are each (partially) cylindrical.

Fig. 1 shows a first embodiment in which the edge protection elements 5 "homogeneous" are made of one and the same material. It can be z. B. hard body of hard metal or hard metal-like materials (eg., Cermets) act. Alternatively, the hard bodies may also be made of a metal matrix composite. In the in Fig. 1 illustrated embodiment, the edge protection elements or hard body 5 in the recesses without screws, z. B. attached by gluing or soldering.

Fig. 2 shows in an alternative embodiment, edge protection elements 5, each having a support member 5b and a wear layer 5c arranged thereon as a composite structure. The carrier element 5b consists of a ductile material, for. Steel. Thus, the carrier element 5b serves primarily to fasten the edge protection element 5 in the recess 3, while the wear layer 5c determines the edge protection properties or wear properties. For this purpose, the wear layer 5c z. B. of a hard metal or a hard metal-like material (eg., Cermet) or preferably also consist of a metal matrix composite material. In this case, it is advantageous to fasten the wear layer to the carrier element 5b by sintering and / or hot isostatic pressing. In the context of manufacturing, consequently, the individual edge protection elements 5 are prefabricated with carrier element 5b and wear layer 5c and then mounted in the recesses 3.

Fig. 2 shows an embodiment in which the edge protection elements 5 are fastened by means of screws to the roller body 2. The edge protection elements 5 therefore have suitable perforations 6 or bores through which the screws can be introduced into the roller body 2. In the illustrated embodiment according to Fig. 2 these holes 6 are arranged for the screws in the region of the support elements 5 and consequently in the region of the ductile material.

Fig. 3 shows an alternative embodiment in which the edge protection elements 5 are positively secured to the roll body 2, by means of a dovetail construction. For this purpose, the edge protection elements 5 each have a mounting web 7 and in the roller body 2 are each arranged in the radial direction of grooves 8 in the region of the individual recesses 3, wherein both the mounting webs and the grooves 8 can be designed dovetailed. Despite this positive connection, it may be appropriate to attach the edge protection elements 5 additionally by gluing or soldering in the recesses 3.

Optional is in Fig. 3 illustrated that these elements 5 may be formed as a composite component with a wear layer 5c and a support member 5b, said wear layer 5c forms a wear insert 5c, which is introduced into a prepared recess of the support member 5b.

The edge protection elements 5 shown in the figures are rectangular in a plan view of the roller. In a side view of the end face of the roller edge protection elements 5 in the embodiment, however - as described - partially rounded. The invention basically also includes embodiments in which the edge protection elements in a side view on the front page polygonal, z. B. rectangular, are formed, so that then z. B. also cuboid edge protection elements can be realized. This is not shown in the figures.

It is also within the scope of the invention to provide the edge protection elements alternatively or additionally on the top with a curved contour, so that in particular an adaptation to the radius of curvature of the roller takes place. This option is not shown.

Incidentally, it is within the scope of the invention, as described, that the recesses 3 and the edge protection elements 5 have a cross-section widening at least in regions in the direction of the roller center. These options are exemplary in the Fig. 4 and 5 shown. Fig. 4 shows an embodiment in which the lower wall portion 3a in an axial section from the roll edge towards the roll center drops, so that an oblique lower edge is formed. The same applies to the corresponding, lower outer contour 5a of the edge protection element 5. This embodiment has the effect that the edge protection elements are securely pressed into the recesses by the pressing forces occurring. Such an embodiment can be realized in the edge protection elements in various forms, eg. B. also in those in the Fig. 1 to 3 illustrated edge protection elements. This applies equally to the in Fig. 5 shown option. Here too, the recesses 3 and the edge protection elements 5 have a cross-section widening at least in regions in the direction of the roller center, this being in Fig. 5 refers to the lateral wall areas or the lateral outer contour. The the Fig. 4 Underlying considerations can therefore be Fig. 5 be provided in the lateral areas of the recesses, these possibilities can also be combined with each other.

Claims (15)

1. A press roll (1) for a roller press, in particular for comminuting highly abrasive materials, comprising a roll body (2) which has a plurality of pocket-like recesses (3) which are distributed over the circumference and are spaced from one another in the circumferential direction (T) on one or both roll edges, which recesses are each configured to be open at the side and at the top,
   wherein in each case only one hard body is inserted as a replaceable edge protection element (5) into the individual pocket-like recesses (3), characterized in that the length (L) of the pocket-like recesses (3) and the length (1) of the inserted edge protection elements (5) in the circumferential direction (T) in the region of the outer upper edges of the edge protection elements (5) is more than five times the spacing (a) between two immediately adjacent recesses (3) in the region of the outer upper edges of the edge protection elements.
2. The press roll (1) according to claim 1, characterized in that the length (L) of the recesses (3) and the length (1) of the edge protection elements (5) is more than ten times the spacing (a).
3. The press roll (1) according to claim 1 or 2, characterized in that the spacing (a) between two directly adjacent recesses (3) is more than 3 mm, preferably more than 4 mm.
4. The press roll (1) according to one of claims 1 to 3, characterized in that the edge protection elements (5) are configured to be angular, for example rectangular when viewed radially onto the roll.
5. The press roll (1) according to one of claims 1 to 4, characterized in that the lateral recesses (3) have curved wall surfaces (3a) in side view, at least in some areas, and the edge protection elements (5) have a curved outer contour (5a) that is adapted to the curved wall surface (3a) at least in some areas.
6. The press roll (1) according to claim 5, characterized in that the curved wall surface (3a) of the recesses (3) and/or the curved outer contour (5a) of the edge protection elements (5) are configured to be arcuate or parabolic or hyperbolic.
7. The press roll (1) according to one of claims 1 to 6, characterized in that each of the edge protection elements (5) has a support element (5b) with a wear layer (5c) arranged thereon, wherein the support element consists of a ductile material of lower hardness than the wear layer (5c).
8. The press roll (1) according to one of claims 1 to 7, characterized in that the edge protection elements (5) or the wear layer (5c) thereof are made of hard metal or a hard metal-like material (Cermet) or a metal matrix composite (MMC).
9. The press roll (1) according to claim 7 or 8, characterized in that the support elements (5b) consist of steel.
10. The press roll (1) according to one of claims 7 to 9, characterized in that the wear layer (5c) is attached onto or on the support element (5b) by sintering and/or hot isostatic pressing (HIP).
11. The press roll (1) according to one of claims 1 to 10, characterized in that the edge protection elements (5) or the support elements (5b) thereof are removably attached to the roll body (2) by screwing, gluing or soldering.
12. The press roll (1) according to one of claims 1 to 11, characterized in that the edge protection elements (5) are removably attached to the roll body (2) by a form-fitting connection, for example by a dovetail connection.
13. The press roll (1) according to one of claims 1 to 12, characterized in that the spacing (a) between two tangentially adjacent recesses (3) decreases or increases from the roll edge in the direction of the roll centre.
14. The press roll (1) according to one of claims 1 to 13, characterized in that the recesses (3) and the edge protection elements (5) each have a cross-section which widens in the direction of the roll centre, at least in some areas.
15. A roller press having two press rolls according to one of claims 1 to 14.

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