AU2015226232B2

AU2015226232B2 - Rolling press

Info

Publication number: AU2015226232B2
Application number: AU2015226232A
Authority: AU
Inventors: Silvio Lorenz; Dirk Schefer; Heinz Schroder
Original assignee: FLSmidth AS
Current assignee: FLSmidth AS
Priority date: 2014-03-06
Filing date: 2015-03-04
Publication date: 2019-03-21
Anticipated expiration: 2035-03-04
Also published as: DE102014102989A1; PE20161420A1; CL2016002233A1; WO2015132302A1; BR112016020647B1; AU2015226232A1; BR112016020647A2

Abstract

A rolling press comprises two rolls (1) forming a nip (3), and at least one side wall (4) delimiting the nip (3) in the direction of the longitudinal axes (2) of the rolls (1), and is characterized by a wear-resistant element (5) for the side wall (4) which is movable transversely to the longitudinal axes (2) of the rolls (1). A movement of the wear-resistant element (5) brings different sections thereof at least into the vicinity of the narrowest portion of the nip (3).

Description

The invention relates to a roller press having two rolls that form a roll nip, and at least one side wall that delimits the roll nip in the direction of the longitudinal axes of the rolls.

In a roller press, bulk material, called the applied material, is supplied from above, drawn into the roll nip formed between the rolls, and during this process is compacted and comminuted.

The applied material is supplied by way of an application shaft disposed above the roll nip. In this regard, side walls of the application shaft regularly project on the face sides of the rollers, all the way into the high-pressure zone in the narrowest part of the roll nip, and prevent the compacted rolled material from exiting there. These therefore also function as a face-side seal relative to the rollers.

In accordance with advancing compaction, the pressure that the rolled material exerts on the side walls of the application shaft in the direction of the longitudinal axes of the rollers increases, and is highest in the high-pressure region. In particular, because of the pressure exerted by the rolled material, the relative movement of the rolled material relative to the side walls, and the abrasive properties of the rolled material, significant wear of the side walls occurs there.

This increased wear is countered by equipping the side walls with hard, wear20 resistant materials. As a function of the operating conditions of the roller presses, particularly of the type and therefore the abrasiveness of the material to be rolled, and of the set width of the roll nip, such wear protection for the side walls must be replaced at defined time intervals. For this purpose, shut-down of the roller press is regularly required, and this means a loss of production.

In DE 100 12 696 B4, a roller press is described, in which the sections of the side walls adjacent to the roll nip are formed by the face sides of piston-shaped wearprotection elements. With advancing wear of the face sides of these wear-protection

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2015226232 19 Oct 2018 elements, these can be made to follow the direction of the rolls by way of an adjustment apparatus. In this way, it is supposed to be possible to clearly reduce the shut-down times of the roller press required for replacing the wear-protection elements as compared with those roller presses in which wear-protection elements are simply replaceably disposed on the insides of the side walls.

A disadvantage of the roller press known from DE 100 12 696 B4 is the significant design effort for integration and, in particular, for sealing the gap formed between the wear-protection elements and the side walls.

A similar roller press is furthermore known from DE 665 141. In this press, wear10 protection elements disposed in recesses of the side walls are also known, which elements are mounted so as to move in the direction of the face surfaces of the rolls. In this regard, it is provided to press the wear-protection elements against the face sides of the rolls by way of weights or under the force of springs, thereby achieving repositioning in the case of increasing wear of the wear-protection elements.

In this embodiment of a roller press, as well, sealing of the gap formed between the wear-protection elements and the rest of the side wall represents a problem. Furthermore, adaptation of the weight or spring load to changing operating conditions can become necessary in order to prevent the wear-protection elements from being lifted too far off the face sides of the rolls by the pressure in the roll nip or from lying against the rolls under overly great pressure.

Proceeding from this state of the art, the invention was based on the task of reducing shut-down times of a roller press, which occur in the case of conventional roller presses as the result of replacement of wear-protection elements, to the greatest possible extent, in simple manner, in terms of design.

The present invention provides a roller press having two rolls that form a roll nip, and at least one side wall that delimits the roll nip in the direction of the longitudinal axes of the rolls, a wear-protection element for the side wall is provided, according to the invention, which element can be displaced transverse, preferably perpendicular to

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2015226232 19 Oct 2018 the longitudinal axes of the rolls, thereby making it possible to position different sections of the wear-protection element at least adjacent to the narrowest part of the roll nip, by means of displacement.

A method according to the invention, for operation of such a roller press, provides 5 that the wear element is displaced as a function of its wear state, into at least the section adjacent to the roll nip, particularly the narrowest part of the roll nip.

Accordingly, the wear-protection element can be disposed with a section adjacent to the narrowest part of the roll nip until a wear limit has been reached. Thereupon, the wear-protection element can be displaced until a new section that has not yet reached the wear limit is disposed adjacent to the narrowest part of the roll nip. Such displacement of the wear-protection element can be carried out without shut-down of the system and thereby without any loss of production caused as a result. In particular, it can also be provided that multiple wear-protection elements are provided, which are used directly one after the other, so that a first wear-protection element, after its last section has reached the wear limit, is displaced out of the region adjacent to the narrowest part of the roll nip, and, at the same time or subsequently, a second wear-protection element is displaced in order to position it with a section adjacent to the narrowest part of the roll nip.

Displacement of the wear-protection element preferably takes place discontinuously and thereby at regular or irregular time intervals, by a defined distance, in each instance. However, (slow) continuous displacement of the wear-protection element is also possible.

The wear-protection element can particularly be a component separate from the side wall. In this regard, the wear-protection element can preferably be guided so as to move in a guide on the side of the side wall adjacent to the face sides of the rolls. As a result, simple integration of the wear-protection element into the side wall, in terms of design, can be achieved. Furthermore, sealing problems such as those that occur in the integration of wear-protection elements that are guided to move in the direction

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2015226232 19 Oct 2018 of the longitudinal axes of the rolls, as known from DE 100 12 696B4 or from DE 665 141, into openings of the side walls, can be prevented.

However, it is also possible to configure the wear-protection element as an integral part of the side wall, in which wall this element can be displaced in an opening, relative to the rest of the side wall. Likewise, it is possible to configure the entire side wall as a wear-protection element and to configure it, accordingly, so as to be displaceable in a direction transverse to the longitudinal axes of the rolls.

In order to ensure that the wear-protection element is not displaced by the rolled material that is moved relative to it, as long as the wear limit in the section adjacent to the narrowest part of the roll nip has not yet been reached, means for fixation of the wear-protection element in different positions relative to the rolls, as needed, can be provided in a preferred embodiment of the roller press according to the invention. These means for fixation can be configured in any desired manner, for example as passive means, such as shape-fit and/or force-fit mountings (e.g. a screw connection), for example.

Fundamentally, a “wear-protection element” is understood to be an element that is functionally provided for protecting the side wall in at least one section, against rapid wear caused by the rolled material and/or the rolls. In this regard, the wear-protection element should (but does not have to) consist, at least on the side adjacent to the roll nip, of a material that is more wear-resistant in comparison with a basic material from which the side wall is essentially made.

Of course, the wear-protection element can also consist entirely of such a relatively wear-resistant material. If applicable, however, configuration of the wear-protection element using a basic body that consists of a cost-advantageous material and a relatively wear-resistant wear-protection layer can prove to be more economically advantageous. In this regard, the wear-protection layer can be formed, for example, by wear-resistant weld cladding. Facing of the basic body with wear-resistant elements, such as hard-metal elements, for example, is also possible.

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The wear-protection element can also consist, on multiple sides, of a material that is more wear-resistant in comparison with the basic material of the side wall or of a basic body of the wear-protection element. This can make it possible to continue to use the wear-protection element after all the sections on the side adjacent to the roll nip have reached the wear limit, by turning it.

Furthermore preferably, it can be provided that the wear-protection element forms multiple wear-protection zones on the side adjacent to the roll nip, which zones differ with regard to their wear resistance. Thus, it can be provided, for example, that a central zone of the wear-protection element, which zone is disposed to cover the narrowest part of the roll nip, is formed from a particularly wear-resistant and therefore comparatively more expensive material, if applicable, while edge-side zones of the wear-protection element, which are not disposed to cover the narrowest part of the roll nip, are formed from a less wear-resistant and therefore more costadvantageous material, if applicable.

In a preferred embodiment of the roller press according to the invention, it can be provided that the wear-protection element extends from an application shaft, by way of which the applied material can be introduced into the roller press, in the direction of the narrowest part of the roll nip. This can allow simple introduction and/or handling of the wear-protection element by way of the application shaft.

The movement direction of the wear-protection element can preferably be aligned parallel to tangentials of the rolls in the narrowest part of the roll nip and, in particular, perpendicular to the plane defined by the (parallel) longitudinal axes of the rolls.

Furthermore preferably, it can be provided that the wear-protection element can be automatically displaced by drive means. This can allow convenient, particularly also automatic repositioning of the wear-protection elements. Such drive means can also perform the function of means for fixation of the wear-protection element in different positions relative to the rolls, as needed, in that in the inactive state, i.e. when they do

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2015226232 19 Oct 2018 not actively displace the wear-protection element, they prevent unwanted displacement of the wear-protection element.

Furthermore, a control unit can be provided for automatic repositioning, which unit is formed in the section adjacent to the roll nip and, in particular, the narrowest part of the roll nip, to control the drive means as a function of the wear state of the wearprotection element. In this regard, the wear state can be determined, particularly preferably, by means of a wear sensor. However, it is also possible to estimate the wear state, taking into consideration the operating parameters of the roller press, particularly the type of applied material used, the rotation speed of the rolls, and the width of the roll nip in the narrowest part. This can also be done automatically by means of the control unit.

In a further preferred embodiment of the roller press according to the invention, it can be provided that the wear-protection element covers the roll nip by at least 80 % in its widest part. In this way, the result can be achieved that the entire section of the side wall that is under great stress from the rolled material or applied material is protected by means of the wear-protection element.

The wear-protection element is preferably mounted exclusively (and particularly preferably, exclusively in the one direction) transverse to the longitudinal axes of the rollers, so as to move relative to them. This can be sufficient for implementation of the functionality according to an embodiment of the invention, and furthermore allows formation of a simple guide, in terms of design, for the wear-protection element.

In the following, the invention will be explained in greater detail using an exemplary embodiment shown in the drawings. In the drawings, the figures show, schematically, in each instance:

Fig. 1: a roller press according to an embodiment of the invention; and

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Fig. 2 to 5: different embodiments of a wear-protection element that can be used in the roller press according to Fig. 1.

The roller press shown in Fig. 1, with great simplification, comprises two rolls 1 that are aligned in such a manner that their longitudinal axes 2 run essentially parallel to one another. As a result, a roll nip 3 having a constant width is formed between the rolls 1, which nip forms the least roll nip width in the plane formed by the two longitudinal axes 2. This region represents the narrowest part of the roll nip 3.

For operation, the roller press can be aligned in such a manner that the plane formed by the two longitudinal axes 2 is aligned horizontally, if at all possible. During operation of the roller press, an applied material (not shown) is poured into the roll nip 3 by way of an application shaft. By means of driving the rolls 1 to rotate in opposite directions, in accordance with the direction-of-rotation arrows shown in Fig. 1, the applied material is then gradually drawn into the roll nip 3, and, during this process, is compacted and comminuted. The comminuted rolled material can then fall into a container (not shown) disposed below the roll nip 3, or onto a conveyor belt positioned there.

The application shaft is formed by four walls. In this regard, two side walls 4 are disposed on the longitudinal-side ends of the rolls 1. The side walls 4 are connected with one another on the edge side by means of two transverse walls (not shown), which run approximately parallel to the longitudinal axes 2 of the rolls 1. In Fig. 1, only the rear side wall 4, in the viewing direction, is shown.

During compaction, the rolled material is pressed against the side walls 4 with high pressure. In connection with the speed relative to the rolled material and the multiple strong abrasive properties of the rolled material, the side walls 4 are therefore subject to great wear, which is greatest in the region of the narrowest part of the roll nip 3, because the compaction is strongest there.

Each of the side walls 4 therefore has a wear-protection element 5 assigned to it, on the side facing the rolls 1, which element is disposed centered with reference to the

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2015226232 19 Oct 2018 two rolls 1. The wear-protection elements 5 are each mounted so as to move in a guide, not shown, of the related side wall 4, in a direction that is perpendicular to the longitudinal axes 2 of the rolls 1 and also perpendicular to the plane formed by the longitudinal axes 2. In the case of an approximately horizontal alignment of the plane formed by the longitudinal axes 2 of the rolls 1, provided for operation of the roller press, approximately vertical mobility of the wear-protection elements 5 therefore occurs.

The wear-protection elements 5 can each be automatically displaced by means of a drive apparatus, which can be provided, for example, in the form of an electric actuating motor having a drive pinion 7 that engages into a rack 6 formed by the related wear-protection element 5.

Displacement of the wear-protection elements 5 takes place as a function of the wear state of those sections of the wear-protection elements 5 that are currently situated adjacent to the narrowest part of the roll nip 3. If a wear limit has been reached for these sections of the wear-protection elements 5, these can be displaced by a defined distance by means of the drive apparatuses, thereby positioning new sections, which have not yet reached their wear limit, adjacent to the narrowest part of the roll nip 3. For this purpose, the wear state can be determined by means of a wear sensor 13, in each instance. Control of the drive apparatuses then takes place as a function of measurement signals of the wear sensors 13, by means of a control unit 12. Shutdown of the roller press is not required for displacement of the wear-protection elements 5.

Displacement of the wear-protection elements 5 preferably takes place from above downward (with reference to the direction of gravity). As a result, the wear25 protection elements 5, after they have reached the wear limit over their entire length, can be released from the related guides by means of a final displacement, and drop down from the roller press. Then they can be disposed of, turned for renewed use, or reconditioned. At the same time with release of the worn first wear-protection element 5, a second wear-protection element (not shown), which follows the first

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2015226232 19 Oct 2018 wear-protection element 5 directly in the displacement direction, is positioned adjacent to the narrowest part of the roll nip 3 with a first section. As a result, uninterrupted protection of the side walls 4 by means of wear-protection elements 5 is implemented.

Fig. 2 to 5 show different possibilities for forming the wear-protection elements 5, which are configured as bars having a rectangular cross-section.

In this regard, Fig. 2 shows a wear-protection element 5 in the form of a solid wearprotection body. This therefore consists entirely of a comparatively wear-resistant material, e.g. a hard metal.

In the case of the wear-protection elements 5 according to Fig. 3 and 4, in contrast, a basic body 8 is provided, which is provided on one side (cf. Fig. 3) or on two opposite sides (cf. Fig. 4) with a wear-protection layer 9 composed of a wearresistant material. The wear-protection element 5 with placement of a wearprotection layer 9 on both sides (cf. Fig. 4) is suitable for double use by means of turning, after the one side has been completely worn away.

Fig. 5 shows the possibility of configuring at least the side of a wear-protection element 5, which side faces the face sides of the rolls 1 and is configured to be wearresistant, with different wear-protection zones 10, 11. For example, it can be provided that a central wear-protection zone 10 (with reference to the transverse direction of the wear-protection element 5, which direction is aligned perpendicular to the displacement direction) is provided, which zone is characterized by greater wear resistance as compared with edge-side wear-protection zones 11. In this way, the circumstance is taken into account that, as is illustrated in Fig. 1, only a central section of the wear-protection element 5 (having the wear-protection zone 10) is directly exposed to the rolled material, in each instance, in the case of a greater width of the wear-protection elements 5 in comparison with the width of the roll nip 3 in its narrowest part. Over the full width, in contrast, the wear-protection elements 5 are acted on by the rolled material only with a correspondingly reduced pressure stress.

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Formation of a wear-protection element 5 with different wear-protection zones 10, is possible both in the case of its configuration as a solid wear-protection body according to Fig. 2 and in the case of a configuration having one or more wearprotection layers 9 on a basic body 8 according to Fig. 3 and 4.

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Reference Symbol List

1. roll

2. longitudinal axis of the roll

3. roll nip

4. side wall

5. wear-protection element

6. rack

7. drive pinion

8. basic body

9. wear-protection layer

10. wear-protection zone

11. wear-protection zone

12. control unit

13. wear sensor 15

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Claims

Claims

1. A roller press having two rolls that form a roll nip and at least one side wall that delimits the roll nip in the direction of the longitudinal axes of the rolls, wherein the side wall comprises a wear-protection element, which can be displaced

5 transverse to the longitudinal axes of the rolls, wherein different sections of the wear-protection element can be positioned at least adjacent to the narrowest part of the roll nip by means of displacement, and wherein the wear-protection element has different wear-protection zones, which differ with regard to their wear resistance.

10
2. The roller press according to claim 1, comprising means for fixation of the wearprotection element, as needed, in different positions relative to the rolls.
3. The roller press according to claim 1 or 2, wherein at least on a side adjacent to the roll nip, the wear-protection element comprises a material that is more wearresistant in comparison with the basic material of the side wall.

15
4. The roller press according to claim 3, wherein the wear-protection element comprises a material that is more wear-resistant in comparison with the basic material of the side wall, also on the side facing away from the roll nip.
5. The roller press according to any one of the preceding claims, wherein the wearprotection element has a basic body and a wear-protection layer.

20
6. The roller press according to any one of the preceding claims, wherein the wearprotection element is guided in a guide of the side wall.
7. The roller press according to any one of the preceding claims, wherein the wearprotection element extends from an application shaft of the roller press in the direction of the narrowest part of the roll nip.

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8. The roller press according to any one of the preceding claims, wherein the movement direction of the wear-protection element is aligned parallel to tangentials of the rolls in the narrowest part of the roll nip.
9. The roller press according to any one of the preceding claims, wherein the wear5 protection element can be automatically displaced by drive means.
10. The roller press according to claim 9, comprising a control unit for controlling the drive means as a function of the wear state of the wear-protection element in the section adjacent to the roll nip.
11. The roller press according to claim 10, comprising a wear sensor for determining

10 the wear state of the wear-protection element in the section adjacent to the roll nip.
12. The roller press according to any one of the preceding claims, wherein the wearprotection element delimits the roll nip laterally by at least 80 %.
13. The roller press according to any one of the preceding claims, wherein the wear15 protection element can be displaced exclusively in a direction transverse to the longitudinal axes of the rolls, relative to the latter.
14. The roller press according to any one of the preceding claims, wherein a central zone of the wear-protection element, which is disposed to cover the narrowest part of the roll nip, is formed from a material that is more wear-resistant than a

20 material, from which edge-side zones of the wear-protection element, which are not disposed to cover the narrowest part of the roll nip, are formed.
15. A method for operating a roller press according to any one of the preceding claims, wherein the wear-protection element is displaced as a function of its wear state at least in the section adjacent to the narrowest part of the roll nip.