EP3774054B1 - Grinding roller and roller press - Google Patents

Description

The invention relates to a grinding roller for a roller press and a roller press with two grinding rollers that form a roller gap.

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

The ground material is usually fed in via a feed chute arranged above the roll gap. Side walls of the feed chute can regularly extend at the front sides 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 ground material in order to keep it within the roll gap.

As an alternative to the integration of side guides for the material to be ground into a feed shaft arranged above the roll gap of a roller press, it can also be provided to provide one of the grinding rollers with a side wall at each of the two axial ends, which is firmly connected, specifically screwed, to a cylindrical roller body of this grinding roller and which projects beyond the outer surface of this roller body on the outside (cf. EP 2 653 230 A2 or EP 3 248 685 A2 ).

As the compaction progresses, the pressure exerted by the material to be ground 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 roller gap. In particular, the pressure exerted by the material to be ground results in considerable forces being exerted on the side guides, which, in conjunction with the movement of the material to be ground relative to the side guides and the usually highly abrasive properties of the material to be ground, cause considerable wear on the side guides. If the side guides are designed in accordance with the EP 2 653 230 A2 or the EP 3 248 685 A2 In addition, the forces exerted on the side guides or side walls have a high dynamic component, which causes a corresponding dynamic stress state in the screws used to connect the side walls to the roller body, which limits the service life of these screws or, in the case of a structurally predetermined service life of the screws, limits the dynamic load and thus the performance of the roller press. In the US 2014/0361108 A1 discloses a grinding roller with side walls attached to the roller body, wherein the side walls are screwed to the roller body.

The invention is based on the object of providing a roller press as described in EP 2 653 230 A2 or the EP 3 248 685 A2 It is known to achieve, in the simplest possible way, a relatively high level of performance with a relatively long service life for the fastening of the side walls which serve as lateral guides for the ground material.

This object is achieved 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 the subject matter of the further patent claims and/or emerge 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 outer surface) and at least one, preferably circular (ring)-shaped side wall arranged on a front side of the roller body and connected to the roller body in a rotationally fixed manner, which projects beyond the outer surface of the roller body (in particular completely). Furthermore, it is provided that the connection between the roller body and the side wall is effected by means of at least one screw connection, wherein the side wall in the In the unconnected state, i.e. when the screw connection provided for the connection has at least not yet been tightened with a defined target tightening torque, in a first section, in which preferably no screw connection is arranged, it 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 side wall and the end wall of the roller body. In contrast, in the connected state, i.e. when the screw connection provided for the connection is tightened with the defined target tightening torque, this gap is at least partially eliminated (i.e. the gap width is reduced), preferably completely, as a result of elastic deformation of the side wall. The grinding roller further comprises at least one further section, in which a gap is formed between the side wall and the end wall of the roller body even in the connected state.

Due to this design of the grinding roller, relatively high axial forces (i.e. forces that act on the side wall along the longitudinal or rotational axis of the grinding roller or the roller body), which result from a correspondingly high grinding performance 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 a particularly strong increase in the contact pressure within the first section can be achieved as a result of the elastic deformation of the side wall when the screw connection is tightened with the target tightening torque. If, on the other hand, the side surface were to rest against the front side of the roller body in the second section even 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 would prevent the side wall from lifting off during operation. (in this first section) from the front side of the roller body and thus ensures sufficient sealing or lateral guidance for the ground material.

Since such a sealing effect is particularly important in the area of the outer surface of the roller body, it can preferably be provided that the first section is located radially further outward 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 area formed between the side wall and the front side of the roller body, in which the side wall rests against the front wall of the roller body in the unconnected state, the third section being located radially further inside than the second section. This makes it possible to achieve an advantageous, defined elastic deformation of the side wall within the scope of the connection, which is brought about by tightening the screw connection(s). It can also preferably be provided that the first section and/or the second section and/or the third section, if present, is/are formed in a closed, circumferential manner, i.e. in a ring shape.

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 side wall and the end wall of the roller body even in the connected state. This further section, which can preferably also be designed to be annular or closed all the way around, 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 between the second section and the third section. In this way, an advantageous connection between the side wall and the roller body can be realized, which in particular is based on contact in the first section and the second section and, where applicable, that is to say, where applicable, in the third section.

The side wall of a grinding roller according to the invention can preferably be formed from a plurality of segments, i.e. from parts that each cover only a circumferential section of the front side of the roller body, with each segment being connected to the roller body by means of at least one screw connection and with the adjacent segments additionally being connected to one another in such a way that axial forces can be transmitted by means of this connection(s). Such segmentation advantageously enables individual segments or all segments and thus the entire side wall to be replaced without having to dismantle the entire grinding roller from the assembly in which it is integrated to form the roller press. The segments can in particular be lifted off in a simple manner from a roller shaft or roller axis that penetrates the grinding roller and thus both the roller body and the side wall(s). The connection between adjacent segments that transmits axial forces means that the side wall as a whole can support relatively high axial forces.

According to a preferred embodiment, the connections between adjacent segments can be provided in the form of at least one tongue-groove pairing integrated into adjacent contact surfaces of the segments. Such a tongue-groove pairing, in which a recess is made in at least one of the contact surfaces, into which a body (spring, in particular a feather key) serving as a transmission element engages, whereby the spring can be designed as a projection of the other contact surface or as a separate component, can be used to transmit very high (axial) forces in a structurally very simple manner. Furthermore, such a connection can also enable the adjacent segments to be loosened and attached without tools in order to dismantle or replace the crosswind or at least one segment thereof.

According to a preferred development of such a grinding roller according to the invention, it can also be provided that the spring of the spring-groove pairing is made of a material whose yield point is lower than the yield point of the material of at least that section of the segment or segments in which the groove of the spring-groove pairing is formed. As a result, particularly high (axial) forces can be transmitted safely by means of such a spring-groove pairing, because the pressure between the spring and the surfaces delimiting the groove and thus also the material stress in the groove radii can be limited, because the spring deforms elastically or possibly also plastically and can therefore lead to the most uniform possible pressure load between the contact surfaces of the spring and those of the associated groove.

As an alternative to a design of a grinding roller according to the invention with a segmented side wall, i.e. formed from several segments, it can also be provided that the side wall is unsegmented and possibly even formed in one piece. This makes it possible to avoid weak points that are formed in the area of the connection of adjacent contact surfaces of the segments. A disadvantage of such an unsegmented side wall, however, can be the increased assembly effort, in particular for replacing such a side wall.

According to a further preferred embodiment of a grinding roller according to the invention, it can be provided that the roller body has a base body and at least one wear body detachably connected thereto, wherein the wear body forms the second section of the front side of the roller body connected to the side wall. Such a wear body can be specifically exposed to the wear that occurs in particular in the area of the second section. Its detachable connection to the base body of the roller body enables a quick and cost-effective replacement. For adaptation of the wear body, it can also preferably be provided that it is made of a material that is particularly suitable for this wear function (e.g. highly wear-resistant sheet steel), so that if necessary, the base body (e.g. forged steel) and the wear body are made of different materials.

A roller press according to the invention comprises at least two grinding rollers which form or delimit a roller gap, at least one of which is designed as a grinding roller according to the invention. It can be provided that only one of these two grinding rollers is designed according to the invention, with side walls 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 side walls and protrude into the intermediate space laterally delimited by the side walls of the grinding roller according to the invention. Alternatively, it can also be provided that both of the grinding rollers are designed according to the invention, with a side wall 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 side walls and thus also the two side walls are arranged at the two different (axial) ends of the roller press or the grinding rollers.

Fig. 1:

eine erfindungsgemäße Mahlwalze in einer perspektivischen Ansicht;

Fig. 2:

die Mahlwalze in einer Seitenansicht;

Fig. 3:

die Mahlwalze in einem Längsschnitt entlang den in der Fig. 2 mit A - A gekennzeichneten Schnittflächen;

Fig. 4:

einen Schnitt durch eine Seitenwand der Mahlwalze entlang der in der Fig. 2 mit C - C gekennzeichneten Schnittebene;

Fig. 5:

in vergrößerter Darstellung den in der Fig. 3 mit Z gekennzeichneten Abschnitt der Mahlwalze im unverbundenen Zustand;

Fig. 6:

in vergrößerter Darstellung den in der Fig. 3 mit Z gekennzeichneten Abschnitt der Mahlwalze im verbundenen Zustand;

Fig. 7:

in vereinfachter Darstellung eine erfindungsgemäße Walzenpresse gemäß einer ersten Ausgestaltungsform in einer Seitenansicht;

Fig. 8:

die Walzenpresse gemäß der Fig. 7 in einer Aufsicht; und

Fig. 9:

in vereinfachter Darstellung eine erfindungsgemäße Walzenpresse gemäß einer zweiten Ausgestaltungsform in einer Aufsicht.

The invention is explained in more detail below using an embodiment example shown in the drawings. In the drawings:

Fig.1:

a grinding roller according to the invention in a perspective view;

Fig. 2:

the grinding roller in a side view;

Fig. 3:

the grinding roller in a longitudinal section along the Fig.2 cutting surfaces marked A - A;

Fig.4:

a section through a side wall of the grinding roller along the Fig.2 cutting plane marked C - C;

Fig.5:

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

Fig.6:

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

Fig.7:

in a simplified representation, a roller press according to the invention according to a first embodiment in a side view;

Fig.8:

the roller press according to the Fig.7 in a supervision; and

Fig. 9:

in a simplified representation of a roller press according to the invention according to a second embodiment in a plan view.

The Fig. 1 to 6 show an embodiment of a grinding roller 1 according to the invention, which can be used as part of a roller press 2 according to, for example, the Fig.7 and 8th 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 roller 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 according to the Fig. 1 to 5 and comprises a hollow cylindrical roller body 5 and two side walls 7, one of which is connected to one 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 side walls 7 of the first grinding roller 1.

During operation of the roller press 2, the grinding material (not shown) is poured via a feed chute (not shown) into the inlet gusset formed on the top between the grinding rollers 1, 3. By driving the grinding rollers 1, 3 in opposite directions in accordance with the Fig.7 The material to be ground is then gradually drawn into the roller gap 5 and thereby compacted and crushed according to the direction of rotation arrows shown. The side walls 7 of the first grinding roller 1 covering the roller gap 5 at the axial ends of the grinding rollers 1,3 prevent the ground material from escaping from the longitudinal axial ends of the roll gap 5. The crushed ground material emerging at the bottom can fall into a container arranged below the roll gap 5 (not shown) or onto a conveyor belt positioned there.

Each of the circular side walls 7 consists of a plurality of (circular ring) segments 8, each of which is connected to the roller body 6 via a plurality of 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 formed by a base 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 side wall 7 (see in particular Fig. 5 and 6 ). Each contact area formed between one of the side walls 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, ie when the screw connections 9 have not yet been tightened to a desired tightening torque, the side walls 7 in the respective first section 13 and the respective third section 15 already contact the associated end face of the roller body, while within the second section 14 a gap 18 with a gap width of, for example, approx. 0.4 mm is still formed (cf. Fig.5 ). In the connected state, when the screw connections 9 have been tightened to the specified tightening torque, the gap previously formed within the second section 14 is completely eliminated, so that the side walls also contact the corresponding end face of the roller body 6 in this section 14 (cf. 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 side walls 17, however, also in the connected state, contact the respective end faces of the roller body 6, which results in an overall advantageous contact between the side walls 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 side walls 7 are connected to one another 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 spring-groove pairing is primarily 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 runs radially with respect to the longitudinal or rotational axis 4 of the grinding roller 6, the grooves of adjacent contact surfaces overlapping and thereby forming a receiving space within which a (key) spring 19 is arranged (cf. Fig.4 ). Axial forces can be transmitted between adjacent segments 8 of the side surfaces 7 via this spring 19. At the same time, the spring-groove pairings do not prevent a segment 8 from being lifted off in the radial direction, which consequently enables easy dismantling and, if necessary, replacement of individual segments 8 or even the side walls 7 as a whole. In particular, this makes it possible for the side walls 7 not to have to be pulled off in the axial direction from a roller axis or roller shaft 20 of the grinding roller 1 for replacement. A cover plate 21 is used to cover the spring-groove pairing, which is screwed to the two adjacent segments 8 by means of two screw connections 22 (see in particular Fig.4 ).

As can be seen in particular from the Fig. 5 and 6 The roller body 6 of the grinding roller 1 comprises, in addition to the base body 11, two ring-shaped wear bodies 23, each of which is arranged at one of the two axial ends of the base body 11. The wear 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 lying between them. The wear bodies 23 are each connected to the associated side wall 7 and the associated screw connections 9 are connected to the base body 11 of the roller body 6 by the side wall 7 pressing the respective wear body 23 into a correspondingly formed recess in the base body 11. The threaded bolts 10 of the associated screw connections 9 each protrude through one of a corresponding number of through-openings in the wear body 23. The wear bodies 23 consist, for example, of highly wear-resistant sheet steel, while the base body of the roller body is made of forged steel. The side walls can in particular be made of sheet steel.

In sections located at the two axial ends, the base body 11 of the roller body 6 forms a plurality of receiving openings 24 open to the outer surface, which serve to receive wear protection bodies, for example made of a hard metal.

The side walls 7 are further 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.

The Fig.9 shows an alternative design for a roller press 2 according to the invention. In this, each of the grinding rollers 1 is provided with a (single) side wall 7 according to the invention, the design and connection of which with the respective roller bodies 6 corresponds to the side walls 7 of the grinding roller 1 according to the Fig. 1 to 6 can be provided. In order to achieve a covering of the roll gap 5 on both sides by means of the side walls 7, the individual side walls 7 are arranged at the different ends of the roller press 2 or the grinding rollers 1.

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.

Side wall

8th.

Segment of a side wall

9.

Screw connection

10.

Threaded bolt

11.

Base body of the roller body

12.

Mother

13.

first section of the contact area side wall and roller body

14.

second section of the contact area side wall and roller body

15.

third section of the contact area side wall and roller body

16.

first further section of the contact area side wall and roller body

17.

second further section of the contact area side wall and roller body

18.

gap

19.

Feather

20.

Roller shaft

21.

Connecting plate

22.

Screw connection

23.

Wear parts

24.

Receiving openings

25.

Wear protection layer

Claims (14)

1. Grinding roller (1) having a cylindrical roller body (6) and at least one side wall (7) which is arranged on an end side of the roller body (6) and non-rotationally fixed to the roller body (6), and which protrudes beyond the outer casing surface of the roller body (6) on the outside, wherein the connection between the roller body (6) and the side wall (7) is formed by means of at least one screw connection (9), wherein, in the unconnected state, the side wall (7) bears on the end wall of the roller body (6) in a first section (13) and, in a second section (14), a gap (18) which, in the connected state, is at least partly eliminated as a result of elastic deformation of the side wall (7), is formed between the side wall (7) and the end wall of the roller body (6),
   characterized in that at least one further section (16, 17) is provided, in which, even in the connected state, a gap is formed between the side wall (7) and the end wall of the roller body (6).
2. Grinding roller (1) according to claim 1, characterized in that the first section (13) is located radially further out than the second section (14).
3. Grinding roller (1) according to claim 1 or 2, characterized in that the screw connection (9) is arranged inside the second section (14).
4. Grinding roller (1) according to any one of the preceding claims, characterized by a third section (15) in which, in the unconnected state, the side wall (7) bears on the end wall of the roller body (6), wherein the third section (15) is located radially further inwards than the second section (14).
5. Grinding roller (1) according to any one of the preceding claims, characterized in that the first section (13) and/or the second section (14) and/or the third section (15) is/are circumferentially closed.
6. Grinding roller (1) according to any one of the preceding claims, characterized in that the side wall (7) is formed from a plurality of segments (8), wherein each segment (8) is connected to the roller body (6) by means of at least one screw connection (9), and wherein the mutually adjacent segments (8) are connected to one another in such a way that axial forces can be transmitted by means of said connection(s).
7. Grinding roller (1) according to claim 6, characterized in that a tongue and groove pair is integrated into mutually adjacent contact surfaces of the segments (8).
8. Grinding roller (1) according to claim 7, characterized in that the tongue (19) of the tongue and groove pair is made from a material for which the yield limit is lower than the yield limit of the material of that segment or those segments in which the groove of the tongue and groove pair is formed.
9. Grinding roller (1) according to any one of claims 1 to 5, characterized in that the side wall (7) is non-segmented.
10. Grinding roller (1) according to any one of the preceding claims, characterized in that the roller body (6) has a main body (11) and at least one wearing body (23) detachably connected thereto, wherein the wearing body (23) forms the second section (14) of the end side of the roller body (6) that is connected to the side wall (7).
11. Grinding roller (1) according to claim 10, characterized in that the main body (11) and the wearing body (23) are made from different materials.
12. Roller press (2) comprising two grinding rollers (1, 3) which form a roller gap (5), characterized in that at least one of the grinding rollers (1, 3) is formed according to any one of the preceding claims.
13. Roller press (2) according to claim 12, characterized in that both of the grinding rollers (1, 3) are formed according to any one of claims 1 to 11, wherein an appropriately connected side wall (7) is provided for each of the grinding rollers (1, 3) on one of the end sides of the associated roller body (6), and wherein the end sides of the two grinding rollers (1, 3) that are connected to the side walls (7) are arranged at different ends of the roller press (2).
14. Roller press (2) according to claim 12, characterized in that one of the grinding rollers (1) is formed according to any one of claims 1 to 11, wherein appropriately connected side walls (7) are provided on the two end sides of the associated roller body (6), and the other grinding roller (3) is formed without side walls (7).

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