FI3774054T3 - Grinding roller and roller press - Google Patents

Claims (25)

1 19716347.0 GRINDING ROLLER AND ROLLER PRESS The invention relates to a grinding roller for a roller press and a roller press with two grinding rollers forming a roll gap.

In a roller press, a bulk material, the so-called feed or grinding material, is fed from above, drawn into the roll gap formed between the grinding rollers and compacted and crushed in the process.

The grinding material is usually fed in through a loading chute arranged above the roll gap.

Sidewalls of the loading chute can regularly protrude at the ends of the grinding rollers into the high-pressure zone in the roll gap in order to prevent the compacted rolled material from escaping at the axial ends of the grinding rollers or the roll gap.

These therefore also act as side guides for the grinding material to keep it within the roll gap.

As an alternative to integrating side guides for the grinding material into a loading chute arranged above the roll gap of a roller press, it is also possible to provide one of the grinding rollers at each of the two axial ends with a sidewall which is firmly connected, specifically bolted, to a cylindrical roller body of this grinding roller and which projects beyond the outer surface of this roller body on the outside (see EP 2 653 230 A2 or EP 3 248 685 A2). As compaction progresses, the pressure that the grinding material exerts on the side guides of a roller press in the direction of the longitudinal or rotational axes of the grinding rollers increases and is highest in the high-pressure area within the roll gap.

In particular, the pressure exerted by the rolling stock exerts considerable forces on the side guides, which, in conjunction with the movement of the grinding material relative to the side guides and the usually highly abrasive properties of the grinding material, cause considerable wear to the side guides.

In a design of the side guides according to the roller presses disclosed in EP 2 653 230 A2 or EP 3 248 685 A2, the forces exerted on the side guides or sidewalls have a high dynamic component, which causes a corresponding dynamic stress state in the screws used to connect the sidewalls to the rolling body, which limits the service life of these screws or, if the service life of the screws is predetermined by the design, limits the dynamic load and thus the performance of the roller press.

US 2014/0361108 A1 discloses a grinding roller with sidewalls attached to the roller body, the sidewalls being bolted to the roller body.

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The invention is based on the task of achieving, in a roller press as known from

EP 2 653 230 A2 or EP 3 248 685 A2, a relatively high performance with a relatively long service life of the fastening of the sidewalls serving as side guides for the grinding material in the simplest possible way.

This problem is solved by means of a grinding roller according to patent claim 1 and a roller press according to patent claim 13. Advantageous embodiments of the grinding roller according to the invention and the roller press according to the invention are objects of the further patent claims and/or result from the following description of the invention.

According to the invention, a grinding roller is provided for a roller press, in particular for a high-pressure or material bed roller press, which has a cylindrical roller body (the term cylindrical refers to the shape of the lateral surface) and at least one sidewall which is arranged on an end face of the roller body is connected to the roller body in a rotationally fixed manner and is preferably circular (annular) in shape and projects beyond the outer lateral surface of the roller body (in particular completely) on the outside.

In addition, it is provided that the connection between the roller body and the sidewall is effected by means of at least one screw connection, such that the sidewall in the unconnected state, i.e. when the screw connection provided for the connection has at least not yet been tightened with a defined nominal tightening torque, in a first section,

in which preferably no screw connection is arranged, rests against the end wall of the roller body and in a second section, in which preferably the screw connection is arranged, a gap is formed between the sidewall and the end wall of the roller body.

In contrast, this gap is at least partially (i.e. the gap width is reduced), preferably completely, eliminated in the connected state, i.e. when the screw connection provided for the connection is tightened with the defined target tightening torque, as a result of elastic deformation of the sidewall.

The grinding roller also comprises at least one further section in which a gap is formed between the sidewall and the end wall of the roller body, even when connected.

Due to this design of the grinding roller, relatively high axial forces (i.e. forces acting on the sidewall along the longitudinal or rotational axis of the grinding roller or the roller body), which result from a correspondingly high grinding capacity of a roller press comprising at least one grinding roller (according to the invention), can be compensated with a relatively low tightening torque for the screw connection(s), because as a result of the elastic deformation of the sidewall when tightening the screw connection with the

3 19716347.0 nominal tightening torque, a particularly strong increase in the contact pressure within the first section can be achieved. If, on the other hand, the side surface was already in contact with the end face of the roller body in the second section in the unconnected state, the subsequent formation of the connection by tightening the screw connection would primarily affect the contact pressure within the second section, which would require a particularly high tightening torque in order to ensure a sufficiently high contact pressure in the first section as well, which prevents the sidewall (in this first section) from lifting off the end face of the roller body during operation and thus ensures a sufficient sealing effect or side guide effect for the grinding material. Since such a sealing effect is particularly important in the area of the outer surface of the roller body, it is preferable for the first section to be located radially further outwards than the second section. According to a preferred embodiment of a grinding roller according to the invention, a third section can also be provided in the contact region formed between the sidewall and the end face of the roller body, in which the sidewall bears against the end wall of the roller body in the unconnected state, the third section being located radially further inwards than the second section. This allows an advantageous, defined elastic deformation of the sidewall to be realized as part of the connection, which is brought about by tightening the screw connection(s). In addition, it may preferably be provided that the first section and/or the second section and/or the third section, if present, is/are of closed circumferential design, i.e. annular. According to a further preferred embodiment of a grinding roller according to the invention, it can also be provided that at least one further section is provided in which a gap is formed between the sidewall and the end wall of the roller body even in the connected state. This further section, which can preferably also be annular or have a closed circumferential design, can preferably be arranged between the first section and the second section or between the second section and the third section. Particularly preferably, at least two such further sections can be provided, one of which is arranged between the first section and the second section and another of which is arranged between the second section and the third section. In this way, an advantageous connection between the sidewall and the roller body can be realized, which can in particular be limited to a contact in the first section and the second section and possibly,

i.e. if present, in the third section.

4 19716347.0 The sidewall of a grinding roller according to the invention can preferably be formed from a plurality of segments, i.e. parts which each cover only a circumferential section of the end face of the roller body, such that each segment is connected to the roller body by means of at least one screw connection and such that the adjoining segments are additionally connected to one anather in such a way that axial forces can be transmitted by means of this connection(s). Such segmentation makes it advantageously possible to replace individual segments or even all segments and thus the entire sidewall without having to dismantle the entire grinding roller from the assembly in which it is integrated to form the roller press.

In particular, the segments can be easily lifted off a roller shaft or roller axle that passes through the grinding roller and thus through both the roller body and the sidewall(s). Due to the axial forces transmitted between adjacent segments, relatively high axial forces can be supported by the sidewall as a whole.

According to a preferred embodiment, the connections of adjacent segments can be provided in the form of at least one tongue and groove pair integrated into adjacent contact surfaces of the segments.

Such a tongue and groove pair, in which a recess is made in at least one of the contact surfaces, into which a body serving as a transmission element (a tongue, in particular a parallel tongue) engages, whereby the tongue can be designed as a projection of the respective other contact surface or as a separate component, allows very high (axial) forces to be transmitted in a structurally very simple manner.

In addition, such a connection can also enable the adjacent segments to be detached and attached without tools with the aim of dismantling or replacing the sidewall or at least one segment thereof.

According to a preferred further development of such a grinding roller according to the invention, it can also be provided that the tongue of the tongue and groove pair is formed from a material whose yield limit is lower than the yield limit of the material of at least that section of the segment or segments in which the groove of the tongue and groove pair is formed.

As a result, particularly high (axial) forces can be safely transmitted by means of such a tongue and groove pair, because the pressure between the tongue and the surfaces delimiting the groove and thus also the material stress in the groove radii can be limited, because the tongue deforms elastically or possibly also plastically and can thus lead to a pressure load between the contact surfaces of the tongue and those of the associated groove that is as uniform as possible.

19716347.0 As an alternative to an embodiment of a grinding roller according to the invention with a segmented sidewall, i.e. formed from several segments, it can also be provided that the sidewall is unsegmented and possibly even formed in one piece. This avoids weak points that are formed in the area of the connection of adjacent contact surfaces of the 5 segments. However, the disadvantage of such an unsegmented side panel can be the increased assembly effort, especially for replacing such a side panel. According to a further preferred embodiment of a grinding roller according to the invention, it may be provided that the roller body has a main body and at least one wearing body detachably connected thereto, such that the wearing body forms the second section of the end face of the roller body connected to the sidewall. Such a wearing body can be specifically exposed to the wear that occurs in particular in the area of the second section. Its detachable connection to the main body of the roller body enables quick and cost-effective replacement. To adapt the wearing body, it is also preferable for it to be made of a material that is particularly suitable for this wearing function (e.g. highly wear-resistant sheet steel), so that the main body (e.g. forged steel) and the wearing body are made of different materials if necessary. A grinding press according to the invention comprises at least two grinding rollers which form or delimit a roll gap, at least one of which is designed as a grinding roller according to the invention. It may be provided that only one of these two grinding rollers is designed in accordance with the invention, with sidewalls being provided on the two end faces of the roller body of this grinding roller in accordance with the invention. The other grinding roller can then be designed without sidewalls and project into the space bounded laterally by the sidewalls of the grinding roller according to the invention. Alternatively, it may also be provided that both of the grinding rollers are designed in accordance with the invention, with a sidewall being provided for each of the grinding rollers on one of the end faces of the associated roller body in accordance with the invention. The end faces of the two grinding rollers connected to the sidewalls and thus also the two sidewalls are arranged at the two different (axial) ends of the roller press or the grinding rollers. The invention is explained in more detail below with reference to an example embodiment shown in the drawings. In the drawings is shown:

Fig. 1: a grinding roller according to the invention in a perspective view;

Fig. 2: the grinding roller in a side view;

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Fig. 3: the grinding roller in a longitudinal section along the cut surfaces marked A - Ain Fig. 2;

Fig. 4: a section through a sidewall of the grinding roller along the sectional plane marked C- Cin Fig. 2;

Fig. 5: the section of the grinding roller marked Z in Fig. 3 in the unconnected state in an enlarged view;

Fig. 6: the section of the grinding roller marked Z in Fig. 3 in the connected state in an enlarged view;

Fig. 7: a roller press according to a first embodiment of the invention in a simplified side view;

Fig. 8: the roller press shown in Fig. 7 in a top view; and

Fig. 9: a roller press according to a second embodiment of the invention in a simplified view. Figs. 1 to 6 show an embodiment of a grinding roller 1 according to the invention, which is provided as a component of a roller press 2 according to, for example, Figs. 7 and 8. This roller press 2 comprises two grinding rollers 1, 3, which are aligned in such a way that their longitudinal axes 4 run as parallel to each other as possible. As a result, a roll gap 5 with a constant width is formed between the grinding rollers 1, which is located in the plane formed by the two longitudinal axes 4. A first (1) of the grinding rollers 1, 3 is designed as shown in Figs. 1 to 5 and comprises a hollow cylindrical roller body 5 and two sidewalls 7, one of which is connected to each of the end walls of the roller body 6 located at the axial ends. The second grinding roller 3 does not comprise such end walls 7, the distance between the grinding rollers 1, 3 being selected such that a roller body 6 of the second grinding roller 3 is arranged partially within the intermediate space laterally delimited by the two sidewalls 7 of the first grinding roller 1. During operation of the roller press 2, grinding material {not shown) is poured through, for example, a loading chute (not shown) into the inlet gusset formed at the top between the grinding rollers 1, 3. A counter-rotating drive of the grinding rollers 1, 3 in accordance with the direction of rotation arrows shown in Fig. 7 then gradually draws the grinding material into the roll gap 5, thereby compacting and crushing it. The sidewalls 7 of the first grinding roller 1, which cover the roll gap 5 at the axial ends of the grinding rollers 1, 3, prevent grinding material from escaping from the longitudinal axial ends of

7 19716347.0 the roll gap 5. The grinding material exiting at the bottom can fall into a container (not shown) located below the roll gap 5 or onto a conveyor belt positioned there.

Each of the circular ring-shaped sidewalls 7 consists of a plurality of (circular ring) segments 8, each of which is connected to the roller body 6 through several screw connections 9. The screw connections 9 each consist of a threaded bolt 10, which is screwed with an external thread into an associated internal thread, which is formed by a main body 11 of the roller body 6, and a nut 12, which is screwed onto the threaded bolt 10 on the side facing away from the roller body 6 and rests against the adjacent side of the sidewall 7 (see in particular Figs. 5 and 6). Each contact area, which is formed between one of the sidewalls 7 and the adjacent end face of the roller body 6, is divided into a first section 13, a second section 14, a third section 15 and two further sections 16, 17, each of which has a circular ring shape.

In the still unconnected state, i.e. when the screw connections 9 are not yet each tightened to a set tightening torque, the sidewalls 7 in the respective first section 13 and the respective third section 15 already contact the corresponding end face of the roller body, while a gap 18 with a gap width of, for example, approx. 0.4 mm is still formed within the second section 14 (see Fig. 5). In the connected state, when the screw connections 9 have therefore each been tightened to the target tightening torque, the gap previously formed within the second section 14 is completely eliminated, so that the sidewalls also contact the corresponding end face of the roller body 6 in this section 14 (see Fig. 6). In the two further sections 16, 17, of which a first (16) is located between the first section 13 and the second section 14 and the second (17) between the second section 14 and the third section 15, the sidewalls 17, on the other hand, do not contact the respective end faces of the roller body 6 even in the connected state, which results in an overall advantageous contact between the sidewalls 7 and the respective associated end faces of the roller body 6, namely exclusively in the three spaced-apart, annular sections 13, 14 and 15.

The individual segments 8 of the sidewalls 7 are connected to each other in such a way that these connections can transmit axial forces, i.e. forces that act along the longitudinal or rotational axis 4 of the grinding roller 1. For this purpose, a primary tongue and groove pair is provided in each separation area of adjacent segments 8. In each of the contact surfaces of the segments that form such a separation area, a groove is formed that extends radially with respect to the longitudinal or rotational axis 4 of the grinding roller 6, whereby the grooves of adjacent contact surfaces overlap and thereby form a

8 19716347.0 receiving space within which a (feather) tongue 19 is arranged (see Fig. 4). Axial forces can be transmitted between adjacent segments 8 of the side surfaces 7 through this tongue 19. At the same time, the tongue and groove pairs do not prevent a segment 8 from being lifted off in a radial direction, which means that individual segments 8 or the sidewalls 7 as a whole can be easily removed and, if necessary, replaced. In particular, this means that the sidewalls 7 do not have to be removed from a roller axis or roller shaft 20 of the grinding roller 1 in the axial direction for replacement. A cover plate 21, which is screwed to the two adjacent segments 8 by means of two screw connections 22, serves to cover the tongue and groove pair (see in particular Fig. 4). As can be seen in particular from Figs. 5 and 6, the roller body 6 of the grinding roller 1 comprises, in addition to the main body 11, two annular wearing bodies 23, each of which is arranged at one of the two axial ends of the main body 11. The wearing bodies 23 each form the area of the respective end face of the roller body 6 arranged within the first section 13, the second section 14 and the further section 16 located between them. The wearing bodies 23 are each connected to the main body 11 of the roller body 6 through the associated sidewall 7 and the associated screw connections 9, in that the sidewall 7 presses the respective wearing body 23 into a correspondingly formed recess in the main body 11. The threaded bolts 10 of the associated screw connections 9 each protrude through one of a corresponding number of through-holes in the wearing body 23. The wearing bodies 23 are made of highly wear-resistant sheet steel, for example, while the main body of the roller body is made of forged steel. The sidewalls may be made of sheet steel in particular. In sections located at the two axial ends, the main body 11 of the roller body 6 forms a large number of receiving openings 24 open towards the lateral surface, which serve to receive wear protection bodies, for example made of a hard metal. The sidewalls 7 are also provided with a wear protection layer 25 on the side facing the roller body 6 and in the section projecting beyond the roller body 6 on the outside.

Fig. 9 shows an alternative configuration for a roller press 2 according to the invention. In accordance with the invention, each of the grinding rollers 1 is provided with a (single) sidewall 7, the design and connection of which to the respective roller bodies 6 can be provided in accordance with the sidewalls 7 of the grinding roller 1 as shown in Figs. 1to 6. In order to cover both sides of the roll gap 5 with the sidewalls 7, the individual sidewalls 7 are arranged at the different ends of the roller press 2 or the grinding rollers 1.

9 19716347.0 List of reference symbols

1. Grinding roller

2. Roller press

3. Grinding roller

4, Longitudinal axis of a grinding roller

5. Roll gap

6. Roller body

7. Sidewall

8. Segment of a sidewall

9. Screw connection

10. Threaded bolt

11. Main body of the roller body

12. Nut

13. First section of the contact area sidewall and roller body

14. Second section of the contact area sidewall and roller body

15. Third section of the contact area sidewall and roller body

16. First further section of the contact area sidewall and roller body

17. Secondfurther section of the contact area sidewall and roller body

18. Gap

19. Tongue

20. Roller shaft

21. Connecting plate

22. Screw connection

23. Wearing body

24. Receptacle openings

25. Wear protection layer