EP2125228B1 - Roller mill - Google Patents

Abstract

The invention relates to a roller mill comprising a mill housing, a milling track rotatably supported about a milling axis inside the mill housing, and at least one milling roller, which can be rotated about a milling roller axis and is in rolling engagement with the milling track. Furthermore, an oscillating arm is provided for the rotatable mounting of the milling roller, the arm having a tilt axis, which is disposed parallel to the milling roller axis and is supported outside the mill housing. In addition, the oscillating arm is in operative contact with a hydropneumatic spring system in order to adjust the contact pressure of the milling roller. The oscillating arm is supported outside the milling housing at a distance thereto such that the forces produced by the hydropneumatic spring system are transferred directly, or via pylons, into the mill foundation.

Description

The invention relates to a roller mill with a vertical mill axis.

Such mills are well known in practice and the literature in various embodiments. These roller or roller mills, also referred to as spring force or external power mills, can be used, for example, for comminuting cement raw materials, cement clinker, coal, ore materials and the like. In this case, provided within a mill housing a rotatably mounted around the mill axis Mahlring or Mahlteller with trained thereon grinding path and a plurality of distributed over the circumference of the grinding path and rolling on this grinding path grinding rollers or grinding rollers. During comminution work, the ground material fed in generally centrally to the grinding plate or grinding ring is comminuted on the grinding track between the grinding ring and the grinding rollers, whereby pressing elements ensure that a correspondingly large, generally adjustable grinding force is introduced in this area.

To achieve this, the grinding rollers of these known mill designs can be guided in different ways and employed against the grinding track. Thus, for example, each grinding roller with its roller axis can be mounted on a corresponding rocker arm, by means of which it is pressed mechanically or hydropneumatically by springs elastically against the grinding material bed formed on the grinding track. The rocker arms are generally located outside of the mill housing and have a rotational axis perpendicular to the roller axis. In other known mill designs, the grinding force is introduced by a pressure ring, which is under the action of a preloaded compression spring system and presses the grinding rollers against the grinding path or the befmdliche Mahlgutbett.

US 2005/0023390 A1 shows a vertical roller mill according to the preamble of claim 1.

From the DE 509 212 Furthermore, a roller mill with a rocker arm for rotatably supporting the grinding rollers is known, which has a tilting axis which is arranged parallel to the Mahlrollenachse. However, these mills have the Disadvantage that you can not realize the high forces required for large mills with high throughputs for an efficient grinding and the forces can not be changed easily for different operating conditions. The invention is therefore based on the object to further develop this type of roller mill, so that high forces for efficient grinding can be realized.

According to the invention, this object is solved by the features of claim 1.

The roller mill according to the invention essentially consists of a mill housing, a grinding track rotatably mounted within the mill housing about a mill axis and at least one grinding roller which is rotatable about a grinding roller axis and is in rolling contact with the grinding track. In addition, a rocker arm for rotatably supporting the grinding roller is provided, which has a tilting axis, which is arranged parallel to the Mahlrollenachse and which is mounted outside of the mill housing. Furthermore, at least one standing with the rocker arm in operative contact hydropneumatic spring system for adjusting the contact pressure of the grinding roller is provided.

Furthermore, a first and a spaced second bearing is provided for the storage of the rocker arm about the tilting axis, wherein the tilting axis is aligned parallel to the grinding roller axis and the ratio of the distance between the grinding roller and the first bearing to the distance between the two bearings 1: 0.5 to 1 : 2 is.

A hydropneumatic spring system can be used to produce substantially larger forces than the previously used mechanical spring systems, which enable efficient grinding, in particular in roller mills with high throughputs. In the previous roller mills of this type, the forces of the Anpresssystems and the bearing of the rocker arm on the mill housing were derived, which can lead to higher housing costs and vibration problems of the roller mill when the forces are increased.

It is therefore proposed to store the rocker arm with distance to the mill housing such that the forces resulting from the Anpresssystem be derived directly or via pylons in the mill foundation and in this way no reinforcements of the mill housing are required. The initiation of forces in the mill foundation allows good adjustability of the cylinder force via the associated storage system.

Further embodiments of the invention are the subject of the dependent claims.

The hydropneumatic suspension system may, for example, have a pull cylinder with a storage system or a pressure cylinder with a storage system.

According to one embodiment, the hydropneumatic spring system engages below the Mahlrollenachse on the rocker arm. In another embodiment, the grinding roller is supported at one end of the rocker arm, while the Anpresssystem comes into operative contact with the rocker arm at the other end and the rocker arm is mounted in a central region. In this case, the tilting axis of the oscillating lever can be arranged in the direction of rotation of the grinding path in front of or behind the grinding roller axis. It is also conceivable to move the tilting axis of the rocking lever up to the grinding roller axis upwards or downwards.

Further advantages and embodiments of the invention will be explained in more detail with reference to the description of some embodiments and the drawings.

Fig. 1a und 1b

eine schematische Seitenansicht und Draufsicht einer Rollenmühle gemäß einem ersten Ausführungsbeispiel,

Fig. 2a und 2b

eine schematische Seitenansicht und Draufsicht einer Rollenmühle gemäß einem zweiten Ausführungsbeispiel,

Fig. 3a und 3b

eine schematische Seitenansicht und Draufsicht einer Rollenmühle gemäß einem dritten Ausführungsbeispiel,

Fig. 4a und 4b

eine schematische Seitenansicht und Draufsicht einer Rollenmühle gemäß einem vierten Ausführungsbeispiel,

Fig. 5a und 5b

eine schematische Seitenansicht und Draufsicht einer Rollenmühle gemäß einem fünften Ausführungsbeispiel,

Fig. 6a und 6b

eine schematische Seitenansicht und Draufsicht einer Rollenmühle gemäß einem sechsten Ausführungsbeispiel,

Fig. 7a und 7b

eine schematische Seitenansicht und Draufsicht einer Rollenmühle gemäß einem siebten Ausführungsbeispiel,

Fig. 8

eine schematische Draufsicht einer Rollenmühle gemäß einem achten Ausführungsbeispiel,

Fig. 9

eine schematische Draufsicht einer Rollenmühle gemäß einem neunte Ausführungsbeispiel und

Fig. 10

eine schematische Darstellung der Schwinghebelgeometrie.

In the drawing show

Fig. 1a and 1b

a schematic side view and top view of a roller mill according to a first embodiment,

Fig. 2a and 2b

a schematic side view and top view of a roller mill according to a second embodiment,

Fig. 3a and 3b

a schematic side view and top view of a roller mill according to a third embodiment,

Fig. 4a and 4b

a schematic side view and top view of a roller mill according to a fourth embodiment,

Fig. 5a and 5b

a schematic side view and top view of a roller mill according to a fifth embodiment,

Fig. 6a and 6b

a schematic side view and top view of a roller mill according to a sixth embodiment,

Fig. 7a and 7b

a schematic side view and top view of a roller mill according to a seventh embodiment,

Fig. 8

FIG. 2 is a schematic plan view of a roller mill according to an eighth embodiment, FIG.

Fig. 9

a schematic plan view of a roller mill according to a ninth embodiment and

Fig. 10

a schematic representation of the rocker arm geometry.

In the Fig. 1a and 1b Roller mill shown essentially consists of a mill housing 1, a grinding track 3 rotatably mounted within the mill housing about a mill axis 2 and at least one grinding roller 4 which is rotatable about a Mahlrollenachse 5 and is in Abrolleingriff with the grinding track 3. Furthermore, at least one rocker arm 6 is provided for rotatably supporting the grinding roller 4, which has a tilting axis 7 which is arranged parallel to the grinding roller axis 5 and which is mounted outside of the mill housing 1.

With the rocker arm is a Anpresssystem for adjusting the contact pressure of the grinding roller 4 in operative contact. This pressure system is formed by a hydropneumatic spring system 8 and the rocker arm 6 is at a distance mounted to the mill housing 1 such that the forces resulting from the Anpresssystem be derived directly or via pylons 9, 10, in the mill foundation 11.

Usually, a plurality of grinding rollers, for example two, four or six grinding rollers, are provided in the roller mill. Each of the grinding rollers would then be equipped with its own rocker arm and associated hydropneumatic spring system 8. It would also be conceivable within the scope of the invention that, for example, two rollers are mounted on a rocker arm.

In the illustrated first embodiment, the tilting axis 7 is provided at one end of the rocker arm 6, while the hydropneumatic spring system 8, which has a pull cylinder with storage system, engages the other end of the rocker arm 6. The roller, however, is held in a central region of the rocker arm 6. The Mahlrollenachse 5 is passed through the mill housing 1 to the outside, with a suitable seal is provided. In the rocker arm storage is a two-fold rocker arm bearing with two rocker arms 6, 6a, but have a common tilt axis 7. The hydropneumatic spring system 8 can alternatively but at least expediently engage the oscillating lever 6, which is arranged closer to the grinding roller 4.

The rocker arm mounting is formed by a first and a second spaced bearings 12a, 12b. The bearings can optionally be designed as a rolling bearing and / or as a sliding bearing.

The bearing of the grinding roller 4 can take place via suitable rolling or plain bearings on the non-co-rotating Mahlrollenachse 5. But it is also conceivable that the grinding roller rotatably supported on the Mahlrollenachse 5 and the Mahlrollenachse 5 is rotatably mounted on the rocker arm 6.

Other embodiments will be explained with reference to the further figures, wherein the same reference numerals are used for the same components.

The roller mill according to the embodiment of Fig. 2a and 2 B differs from the first embodiment essentially only in that the hydropneumatic suspension system 8 engages below the Mahlrollenachse 5 on the rocking lever 6. Again, the hydropneumatic suspension system is designed as a pull cylinder. As a result, a direct power line is achieved, since only a small lever for grinding roller is present.

In the embodiment according to the Fig. 3a and 3b the grinding roller 4 is supported at one end of the rocker arm 6, while the hydropneumatic spring system 8 comes into operative contact with the rocker arm at the other end and the rocker arm 6 is mounted in a central region. In this embodiment, the hydropneumatic spring system 8 is designed as a pressure cylinder with a storage system. Printing cylinders are cheaper due to the simpler design than pull cylinder.

In the following, further exemplary embodiments are explained on the basis of very schematically held representations, which relate to different variants of the arrangement of tilting axis 7, grinding roller axis 5 and point of application of the hydropneumatic spring system 8.

In the embodiment according to the Fig. 4a and 4b the tilting axis 7 of the rocking lever is arranged in the direction of rotation 13 in front of the grinding roller axis 5. In the embodiment according to the Fig. 5a and 5b the conditions are reversed accordingly, so that the tilting axis 7 is arranged in the direction of rotation 13 of the grinding track 3 behind the Mahlrollenachse 5.

In addition to a substantially horizontal arrangement of the rocking lever 6 but also an oblique arrangement is conceivable, wherein the tilting axis 7 both above the Mahlrollenachse 5 (see Fig. 6a, 6b ) as well as below the grinding roller axis 5 (see Fig. 7a, 7b ) can be arranged. The hiring of the rocker arm 6 according to the embodiments 6a to 7b reduces the bearing forces in the region of the tilt axis.

While in the embodiments shown so far, the tilting axis 7 and the grinding roller axis 5 are aligned parallel to each other, the tilting axis 7 in the embodiment according to Fig. 8 opposite the grinding roller axis 5 (slightly) set. In this way, the kinematics of the grinding roller 4 can be improved.

Furthermore, it is possible to arrange the grinding roller axis 5 offset from the mill axis 3, as in the embodiment according to Fig. 9 is shown. In this way, if necessary, an improved grinding of the ground material can be achieved by additional friction.

In Fig. 10 the swinging geometry is shown schematically. By changing the leverage ratios and the different distances, different power ratios can be realized.

In the experiments underlying the invention has for the ratio of the distance L2 between the grinding roller 4 and the first bearing 12a to the distance L1 between the two bearings 12a, 12b, a range of 1: 0.5 to 1: 2, preferably 1: 0.7 to 1: 1, proved to be particularly advantageous. Furthermore, a suitable range of 1: 0.8 to 1: 2, preferably from 1: 0.9 to 1: 1.2, was determined for the ratio of the distance L3 between tilting axis 7 and grinding roller axis 5 to the distance L4 between tilting axis 7 and operative contact of the hydropneumatic spring system 8.

Through the use of the hydropneumatic spring system 8 highest grinding forces can be realized, which can be derived easily or directly through pylons 9, 10 in the mill foundation 11. The rocker arm 6 allows a parallel movement of the grinding roller 4 to the grinding path 3 and therefore does not lead to changed geometry ratios in a wear of the grinding rollers, also with this storage and selection of suitable leverage a force application is possible, which is less than or equal to the force generated at the grinding roller. By suitable geometric conditions, the forces on the two bearings 12a, 12b may even be smaller than the forces on the grinding roller. In addition, this type of Mahlrollenlagerung allows the resulting from the grinding tangential force increases the vertical force on the grinding roller.

Claims (14)

1. Roller mill having

   - a mill housing (1),

   - a mill path which is supported so as to be rotatable about a mill axis (2) inside the mill housing,

   - at least one mill roller (4) which can be rotated about a mill roller axis (5) and which is engaged with the mill path in terms of rolling action,

   - at least one pivot lever (6) which is for rotatably retaining the mill roller (4) and which has a pivot shaft (7) which is supported outside the mill housing,

   - and having at least one pressing system being formed by a hydropneumatic resilient system (8) which is in operational contact with the pivot lever in order to adjust the pressing pressure of the mill roller (4),

   characterised in that

   - the bearing of the pivot lever (6) has a first and a second spaced-apart bearing (12a,12b) with a common pivot axis (7),

   - the pivot axis (7) is arranged parallel with the mill roller axis (5),

   - the ratio of the distance (L2) between the mill roller (4) and the first bearing (12a) relative to the distance (L1) between the two bearings (12a, 12b) is from 1:0.5 to 1:2 and

   - the pivot lever (6) is supported with spacing from the mill housing (1) in such a manner that the forces which are produced by the pressing system are dissipated into the mill foundation directly or via pillars.
2. Roller mill according to claim 1, characterised in that the hydropneumatic resilient system (8) has at least one traction cylinder having a storage system.
3. Roller mill according to claim 1, characterised in that the hydropneumatic resilient system (8) engages with the pivot lever (6) below the mill roller axis.
4. Roller mill according to claim 1, characterised in that the hydropneumatic resilient system (8) has at least one pressure cylinder having a storage system.
5. Roller mill according to claim 1, characterised in that the mill roller (4) is retained at one end of the pivot lever (6) whilst the hydropneumatic resilient system (8) moves into operational contact with the pivot lever (6) at the other end and the pivot lever is supported in a central region.
6. Roller mill according to claim 1, characterised in that the pivot axis (7) of the pivot lever (6) is arranged upstream of the mill roller axis (5) in the direction of rotation (13) of the mill path (3).
7. Roller mill according to claim 1, characterised in that the pivot axis (7) of the pivot lever (6) is arranged downstream of the mill roller axis (5) in the direction of rotation (13) of the mill path (3).
8. Roller mill according to claim 1, characterised in that the pivot axis (7) of the pivot lever (6) is arranged so as to be displaced upwards relative to the mill roller axis (5).
9. Roller mill according to claim 1, characterised in that the pivot axis (7) of the pivot lever (6) is arranged so as to be displaced downwards relative to the mill roller axis (5).
10. Roller mill according to claim 1, characterised in that the pivot axis (7) of the pivot lever (6) is arranged so as to be inclined relative to the mill roller axis (5).
11. Roller mill according to claim 1, characterised in that the mill roller axis (5) is arranged so as to be displaced relative to the mill axis (2).
12. Roller mill according to claim 1, characterised in that the bearing (12) of the pivot lever (6) has roller bearings and/or sliding bearings.
13. Roller mill according to claim 1, characterised in that the ratio of the distance (L2) between the mill roller (4) and the first bearing (12a) relative to the distance (L1) between the two bearings (12a, 12b) is from 1:0.7 to 1:1.
14. Roller mill according to claim 1, characterised in that the ratio of the distance (L3) between the pivot axis (7) and the mill roller axis (5) relative to the distance (L4) between the pivot axis (7) and operational contact of the hydropneumatic resilient system (8) is from 1:0.8 to 1:2, preferably from 1:0.9 to 1:1.2.

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