EP1448303B1 - Tube grinder and method for comminuting lumpy grinding stock - Google Patents

Description

The invention relates to a tube mill and a method for crushing lumpy material.

Tube mills, in particular ball mills, are well known. They essentially consist of a first grinding chamber, at least one second grinding chamber and a co-rotating intermediate wall arranged between the grinding chambers. They are used for shredding different materials in various industrial sectors.

The material to be crushed is comminuted during the grinding process of the freely movable Mahlkörperschüttung inside the grinding chamber, being used as a grinding body both spherical and rod or rod-like body.

By using separate grinding chambers, the effective use of grinding media with different geometric design, in particular the use of different diameters in spherical grinding media, is possible. The individual grinding chambers can also have different Mahlkörperfüllungsgrade.

The intermediate walls in the tube mills serve the purpose of separating the grinding media filling of adjacent grinding chambers from one another and to transport the material being ground in a controlled manner from one to the other grinding chamber. For this purpose, a discharge device is usually arranged in the intermediate wall, through which the grist received via entry openings into the intermediate chamber is discharged via a discharge opening into the second grinding chamber.

To increase the efficiency of the tube mill, it is already known that from the first grinding chamber in the intermediate wall entering grinding material in coarse material and fine material to separate, wherein the fine material passes through a discharge opening into the second grinding chamber and the coarse material is thrown back via a discharge cone directly behind the partition into the first grinding chamber.

In the DE 378 026 a tube mill with center discharge is proposed in which both the material to be ground from the first grinding chamber and the material to be ground from the second grinding chamber passes into the intermediate wall and discharged from there together and fed to a viewing device. The coarse return of the sighting device is in turn divided into coarse material and fine material and forwarded to the first and second grinding chamber.

In the WO 00/12218 two separate tube mills are proposed, each with a grinding chamber, each having different inner diameter. The millbase of the first tube mill is fed to a separate classifier, wherein the coarse material is fed back to the first tube mill and the fines to the second tube mill.

From the BE-A-711 701 and the FR-A-1 478 292 tube mills are known according to the preamble of claim 1, each of which eject the fines from the intermediate wall, while the coarse material passes into the second grinding chamber.

The invention is based on the object to improve the efficiency of a tube mill and a method for crushing lumpy material to be ground.

According to the invention, this object is solved by the features of claims 1 and 10.

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

1. a. einer ersten Mahlkammer,
2. b. wenigstens einer zweiten Mahlkammer,
3. c. einer zwischen den Mahlkammern angeordneten, mitrotierenden Zwischenwand,
4. d. einer in der Zwischenwand angeordneten Trenneinrichtung zum Aufteilen des Mahlguts aus der ersten Mahlkammer in eine erste Mahlgutteilmenge und eine zweite Mahlgutteilmenge,
5. e. Mitteln zum direkten oder indirekten Zuführen wenigstens eines Teils der zweiten Mahlgutteilmenge zur zweiten Mahlkammer sowie
6. f. eine Einrichtung zum separaten Ausschleusen der ersten Mahlgutteilmenge aus der Rohrmühle.

The tube mill according to the invention consists essentially of

1. a. a first grinding chamber,
2. b. at least a second grinding chamber,
3. c. a co-rotating intermediate wall arranged between the grinding chambers,
4. d. a separation device arranged in the intermediate wall for dividing the ground material from the first grinding chamber into a first Mahlgutteilmenge and a second Mahlgutteilmenge,
5. e. Means for direct or indirect feeding at least a portion of the second Mahlgutteilmenge to the second grinding chamber and
6. f. a device for separate discharge of the first Mahlgutteilmenge from the tube mill.

In the inventive method for crushing lumpy material to be ground with a tube mill containing at least a first and a second grinding chamber and a co-rotating between the grinding chambers, mitrotierende intermediate wall, the comminuted in the first grinding chamber millbase is divided in an intermediate wall in a first and a second Mahlgutteilmenge, wherein at least a portion of the second Mahlgutteilmenge passes directly or indirectly into the second grinding chamber and at least the first Mahlgutteilmenge is discharged separately from the tube mill.

According to the invention the separating device is formed by a classifying device, so that the first Mahlgutteilmenge consists of coarse material and the second Mahlgutteilmenge consists of fine material. The classifier can be formed, for example, by a sieve or trench wall, a drum screen or Siebhubschaufeln. The discharged first Mahlgutteilmenge can be wholly or partially fed to the Mahlgutaufgabe the first grinding chamber or a Vormahlaggregat.

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

In the drawing show

Fig. 1a - Fig. 1c

schematic representations of a tube mill according to a first embodiment,

Fig. 2a - Fig. 2e

schematic representations of a tube mill according to a second embodiment,

Fig. 3a - Fig. 3b

schematic representations of a tube mill according to a third embodiment,

Fig. 4

schematic representations of a tube mill according to a fourth embodiment,

Fig. 5a - Fig. 5b

schematic representations of a tube mill according to a fifth embodiment,

Fig. 6 - Fig. 12

schematic representations of grinding plants with a tube mill according to the invention according to various variants.

In the Fig. 1a-1c The tube mill shown essentially consists of a first grinding chamber 1, a second grinding chamber 2 and a co-rotating intermediate wall 3 arranged between the grinding chambers. The material to be ground 4 passes through a material feed 5 into the first grinding chamber 1, in which it is rotated about a longitudinal center axis by rotation of the tube mill 6 comes to shredding. Usually both grinding chambers contain so-called grinding media, which are adapted in shape, size, quantity and material to the respective needs.

The first grinding chamber is usually separated from the intermediate wall 3 by a slot wall 3.4, which has openings 3.5, through which the ground material sufficiently comminuted in the first grinding chamber reaches a first intermediate wall region 3.1.

The intermediate wall 3 has, in addition to the first intermediate wall region 3.1, a second intermediate wall 3.3, wherein the two intermediate wall regions are separated from one another by a classifying device 3.2. The integrated classifying device 3.2 divides the material to be ground from the first grinding chamber into a coarse material 8 consisting of first Mahlgutteilmenge and a fine material consisting of 9 second Mahlgutteilmenge. The fine material 9 passes into the second intermediate wall region 3.3 and is there via suitable means, such as lifting elements, the second grinding chamber 2 fed. The coarse material 8 obtained within the classifying device 3.2 is discharged from the tube mill and can be returned to the grinding process at a suitable point (preferably at the grinding stock inlet 4).

In the following, the structure and operation of the intermediate wall 3 based on the Fig. 1b and 1c explained in more detail.

In the illustrated embodiment, the classifying device 3.2 is designed as a screen or diaphragm wall. The first partition wall area 3.1 is thereby bounded by the slot wall 3.4 and the classifying device 3.2 and the second partition wall area 3.3 by the classifying device 3.2 and the partition wall 3 separating from the second grinding chamber 2 end wall 3.6.

The fine material 9 coming from the first grinding chamber 1 via the opening 3.5 into the first intermediate wall region 3.1 passes unhindered via the classifying device 3.2 into the second intermediate wall region 3.3 and is discharged there via a discharge device (not illustrated in particular lifting blades) into the second grinding chamber 2.

The coarse material 8 introduced from the first grinding chamber 1 into the first intermediate wall area 3.1 remains in front of the classifying device 3.2, wherein the coarse material level gradually rises in the first intermediate wall area until it has reached a certain height, at which the coarse material 8 enters a discharge opening 3 within the classifying device 3.2 arranged discharge 3.8 arrived. About an outlet channel 3.9 the coarse material 8 is discharged through a discharge 3.11 from the tube mill.

Depending on the procedural requirements and requirements, the height of the level of the coarse material 8 can be adjusted in front of the classifying device 3.2 by varying the radial distance of the discharge opening 3.10 from the longitudinal central axis 6. The amount of coarse material 8 discharged can be adjusted by varying the size of the discharge opening 3.10.

In Fig. 2a-2e is a tube mill with an intermediate wall 10 according to a second embodiment.

The intermediate wall 10 is divided into at least one, preferably, but several Siebkammem, which are arranged like a segment around the longitudinal central axis 6. Each screen chamber is bounded by radial side walls 10.9, 10.10 and a part of the first grinding chamber 1 facing slot wall 10.4 and a part of the second grinding chamber 2 facing end wall 10.6. Fig. 2b shows a view of belonging to an intermediate wall chamber portion of the slot wall 10.4. Each intermediate wall chamber is subdivided into a first intermediate wall chamber 10. 1 and a second intermediate wall chamber 10. 3 by a sieve lifting vane 10. 2 designed as a sieve. The inlet openings 10.5 of the slot wall 10.4 are provided only in the region of the first partition wall chamber 10.1, so that the ground in the grinding chamber 1 regrind enters through the inlet openings 10.5 in the first partition chamber 10.1. As a result of the rotation of the tube mill, the material to be ground in the first intermediate wall chamber 10.1 is raised above the sieve lifting blades 10.2. The fine material 9 contained in the material to be ground passes through the sieve openings of Siebhubschaufeln 10.2 in the second partition wall portion 10.3 and is passed there via a Feingutabweisblech 10.11 in the second grinding chamber. The coarse material 8, however, runs over the Siebhubschaufeln 10.2 and is then promoted via a Grobgutabweisblech 10.12 in a shaft 10.7. About the mill rotation located in the shaft 10.7 Grobgut 8 is discharged from the tube mill.

The in the Fig. 3a and 3b variant shown shows an intermediate wall 11, in which the separating or classifying device is formed by a sieve drum 11.2, which divides the intermediate wall into an inner first intermediate wall region 11.1 and an outer second intermediate wall region 11.3.

The ground material passes through inlet openings in the slot wall 11.4 in the first intermediate wall region of the screen drum 11.2. On the way to Grobgutaustragskanal 11.5, which is arranged at the end of the sieve drum, the fine material 9 falls through the sieve drum in the second partition wall area 11.3. About conveyor plates 11.6, which are preferably designed as screw plates, the fines 9 is conveyed into the second grinding chamber 2. The coarse material 8 is collected in Grobgutaustragskanal 11.5 and discharged via a Grobgutaustragsschacht from the tube mill.

The embodiment according to Fig. 4 shows a tube mill with a first grinding chamber 1, a second grinding chamber 2 and arranged between two grinding chambers, mitrotierenden intermediate wall 3. In the intermediate wall, a classifying device is provided, for example, according to one of the in the Fig. 1-3 illustrated variants may be formed.

The inner diameter of the first grinding chamber 1 is smaller than the inner diameter of the following in the material flow direction grinding chamber 2. By such a step jump an optimized geometry can be generated, which takes into account the Mahlkörperfüllungsgrad, the Mahlkörperabmessungen, the type of ground material, etc..

While in all the variants shown so far, the fine material passes directly into the second grinding chamber via an end wall separating the intermediate wall from the second grinding chamber, according to the exemplary embodiment Fig. 5a and 5b provided a so-called center discharge. In such a tube mill, both the ground material from the first grinding chamber 1 and the ground material from the second passes Grinding chamber 2 in a co-rotating intermediate wall 13 arranged between the two grinding chambers. The intermediate wall 13 in turn contains a classifying device 13.2, which may be designed, for example, according to one of the variants indicated above. In the illustrated embodiment, it is formed by a sieve wall. The classifier 13.2 again separates the intermediate wall into a first intermediate wall region 13.1 and a second intermediate wall region 13.3.

The intermediate wall 13 is delimited to the first grinding chamber 1 via a slot wall 13.4 and the second grinding chamber 2 via a slot wall 13.6. The millbase from the first grinding chamber 1 passes through inlet openings 13.5 in the first partition wall area 13.1. The ground material from the second grinding chamber 2 passes through inlet openings 13.7 into the second intermediate wall region. The classifying device 13.2 designed as a screen wall allows the fine material to pass from the first intermediate wall region 13.1 into the second intermediate wall region 13.3.

The coarse material 8 from the first partition wall area 13.1 is discharged separately via first discharge means 13.8. The fine material 9 and the material to be ground 12 from the second grinding chamber 2 are discharged via second discharge means 13.9 from the tube mill. According to Fig. 5a For example, the material discharged from the second intermediate wall region 13.3 is preferably fed to a separator 16. The material is there divided into finished product 15 and classifier 14, wherein the classifier, preferably on a Mahlgutaufgabe 17 of the second grinding chamber 2, are returned to the grinding process again.

In the following, various grinding plants are described, each having a tube mill, which consist essentially of a first grinding chamber 1, a second grinding chamber 2, and arranged between the grinding chambers, co-rotating intermediate wall 30. In the intermediate wall, a separating device 32 for dividing the ground material from the first grinding chamber 1 in a first Mahlgutteilmenge 8 and a second Mahlgutteilmenge 9 is provided. Although the separating device is preferably designed as a classifying unit, can in this area only a quantitative distribution can be made. In this way, two or three streams of material can be led out separately from the tube mill, resulting in advantages for the procedural material management. In particular, the residence time in the two grinding chambers can be influenced and controlled and, if appropriate, used to optimize the working requirement.

The in the Fig. 6-12 shown tube mills can in particular according to one of Fig. 1-5 be described embodiments described.

In Fig. 6 a tube mill is operated in the closed grinding circuit with a classifier 40. The ground material of the first grinding chamber 1 enters the intermediate wall 30 and is divided there into a first Mahlgutteilmenge 8 and a second Mahlgutteilmenge 9. While the first Mahlgutteilmenge 8 is discharged from the tube mill, passes the second Mahlgutteilmenge 9 in the second grinding chamber 2. The discharged from the second grinding chamber 2 Good 18 is given to a classifier 40, which can be formed by a static or dynamic separator or classifier. The fine material of the classifying apparatus is discharged as finished product 19, while the coarse material 20 is transported via a material divider 41 partly or completely into the second grinding chamber 2 or into the first grinding chamber 1. In addition to the coarse material 20, which may be recirculated by the classifier 40, the first grinding chamber 1 is also supplied with the first millbase subset 8 and the fresh material 21.

In the Fig. 7 Milling plant shown differs from the previous embodiment in that the discharged from the intermediate wall first Mahlgutteilmenge 8 is fed to a classifier 50. The first Mahlgutteilmenge 8 is thus classified outside the tube mill, wherein the coarse material portion of the first grinding chamber 1 is abandoned. The fines of the classifying apparatus 50 can be fed via a material divider 51 completely or partly to the second grinding chamber 2 or the classifying apparatus 40.

In Fig. 8 The tube mill is operated in a closed grinding circuit with a classifier 40 and a Vorzerkleinerungsstufe. In contrast to the grinding plant according to Fig. 6 the fresh product 21 is fed to a grinding unit 60, which pre-shreds the Malgut. The entire or a part of the pre-shredded material is then the first grinding chamber 1 abandoned. A material divider 61 makes it possible to recirculate part of the pre-shredded material back to the grinding unit 60.

The discharged from the tube mill first Mahlgutteilmenge can be supplied via a splitter 52 completely or only part of the first grinding chamber 1 or the grinding unit 60.

Fig. 9 shows the variant according to Fig. 7 in conjunction with a grinding unit 60 according to Fig. 8 , The coarse material of the classifying apparatus 50 can thereby be given up completely or partly to the first grinding chamber 1 or the grinding unit 60.

The grinding plant according to Fig. 10 provides a pre-crushing stage with a milling unit 60 in conjunction with a classifier 62. The classifying apparatus can be designed as a static or dynamic classifier.

The discharged from the tube mill first Mahlgutteilmenge 8 can be supplied via a material divider 53 in part or completely the first grinding chamber 1, the classifying apparatus 62 or the classifying apparatus 40. The fines of the classifying apparatus 62 are supplied via a material divider 64 either completely or partly to the second grinding chamber 2 or the first grinding chamber 1. The coarse material of the classifying apparatus 62 passes via a material divider 63 either completely or partially into the first grinding chamber 1 and / or to the grinding unit 60, which is thus operated on the one hand with fresh material 21 and on the other with coarse material from the classifying apparatus 62. The coarse material of the grinding unit 60 then passes into the Classifying apparatus 62. There is also the possibility of giving up fresh goods 22, bypassing the pre-shredding, directly to the first painting chamber.

The grinding plants according to Fig. 11 and 12 use tube mills with a center discharge. In the embodiment according to Fig. 11 in turn, the first Mahlgutteilmenge 8 is discharged separately. The second Mahlgutteilmenge 9 is discharged together with the entering from the second grinding chamber 2 in the intermediate wall material to be ground 23 and the classifying machine 40 abandoned. The coarse material of the classifier 40 is partially or completely abandoned via a material divider 41 of the second grinding chamber 2. Another part can be returned to the first grinding chamber 1. The first Mahlgutteilmenge 8 is supplied via a material divider 53 partially or completely the first grinding chamber 1, the classifier 40 or the classifier 62.

The variant according to Fig. 12 differs from the grinding plant according to Fig. 11 in that the second millbase subset 9 and the millbase 23 entering the intermediate wall 2 are discharged separately from one another, so that three material streams, namely the first millbase subset 8, the second millbase subset 9 and the mill base 23, are discharged from the tube mill. The first Mahlgutteilmenge 8 is supplied as before a material divider 53. The material to be ground 23 from the second grinding chamber passes directly into the classifying apparatus 40 while the second Mahlgutteilmenge 9 via a material divider 54 partially or completely the second grinding chamber 2 and / or the classifying machine 40 is abandoned.

The above-mentioned variants of grinding plants are to be understood as exemplary only. However, they show that the discharged first Mahlgutteilmenge can be supplied in a variety of ways upstream or downstream equipment parts. This allows better grinding efficiency and material handling advantages, which can reduce specific workload.

Claims (18)

1. A tube mill comprising

   a. a first grinding chamber (1),

   b. at least one second grinding chamber (2),

   c. a jointly rotating partition (3) arranged between the grinding chambers,

   d. a classifier (3.2), arranged in the partition, for dividing the grinding material from the first grinding chamber into a first grinding-material quantity (8) and a second grinding-material quantity (9),

   e. means for supplying at least some of the second grinding-material quantity to the second grinding chamber,

   f. a device (3.8) for separately discharging the first grinding-material quantity from the tube mill,

   characterised in that the classifier (3.2) is formed so that the first grinding-material quantity consists of coarse material and the second grinding-material quantity consists of fine material.
2. A tube mill according to claim 1, characterised by means for supplying the discharged first grinding-material quantity to the grinding-material feeder (5) of the first grinding chamber.
3. A tube mill according to claim 1, characterised in that the means for supplying the second grinding-material quantity to the second grinding chamber (2) are arranged so that the second grinding-material quantity (9) passes into the second grinding chamber (2) via an end wall (3.6) separating the partition from the second grinding chamber.
4. A tube mill according to claim 1, characterised in that the partition has a first and a second partition region (3.1, 3.3), wherein the two partition regions are separated from one another by the separator (3.2), and the device for discharging the first grinding-material quantity from the tube mill communicates with the first partition region and the means for supplying the second grinding-material quantity to the second grinding chamber communicate with the second partition region.
5. A tube mill according to claim 1, characterised in that the inner diameter of the first grinding chamber (1) is smaller than the inner diameter of the second grinding chamber (2).
6. A tube mill according to claim 1, characterised in that the separator is formed by a screening or slotted wall (3.2).
7. A tube mill according to claim 1, characterised in that the separator is formed by a screening drum (11.2).
8. A tube mill according to claim 1, characterised in that the separator is formed by lifting vanes provided in the partition, wherein the lifting vanes are formed as screening lifting vanes (10.2).
9. A tube mill according to claim 1, characterised by means (13.7) for transferring the grinding material from the second grinding chamber (2) to the partition (13) and means (13.9) for discharging the material coming from the second grinding chamber and for discharging the second grinding-material quantity from the tube mill.
10. A method of comminuting lumpy grinding material in a tube mill, containing at least one first and one second grinding chamber (1, 2) and a jointly rotating partition (30) arranged between the grinding chambers, wherein the grinding material ground in the first grinding chamber is classified in the partition and divided into a first and a second grinding-material quantity (8, 9), wherein the one grinding-material quantity (8) consists of coarse material and the other (9) consists of fine material, and wherein at least some of the second grinding-material quantity (9) passes into the second grinding chamber (2) and at least the first grinding-material quantity (8) is discharged separately from the tube mill, characterised in that the first grinding-material quantity (8) is formed by the coarse material and the second grinding-material quantity (9) is formed by the fine material.
11. A method according to claim 10, characterised in that at least some of the discharged first grinding-material quantity (8) is fed back to the grinding-material feeder of the first grinding chamber (1).
12. A method according to claim 10, characterised in that one part of the discharged first grinding-material quantity (8) is fed back to the grinding-material feeder of the first grinding chamber (1) and the other part is fed back to a classifying apparatus (40) arranged outside the tube mill.
13. A method according to claim 10, characterised in that the discharged first grinding-material quantity (8) is fed back to a classifying apparatus (40, 62) arranged outside the tube mill.
14. A method according to claim 10, characterised in that the grinding material ground in the second grinding chamber (2) is fed to a classifying apparatus (40) arranged outside the tube mill, wherein the coarse material (20) accumulating therein is fed back to the second grinding chamber (2) and/or to the first grinding chamber (1).
15. A method according to claim 10, characterised in that the grinding material to be supplied to the tube mill is first fed to a precomminuting stage (60).
16. A method according to claim 10, characterised in that the grinding material to be supplied to the tube mill is first fed to a precomminuting stage and in that one part of the discharged first grinding-material quantity (8) is fed to the precomminuting stage again, while the other part is conveyed to the grinding-material feeder of the first grinding chamber.
17. A method according to claim 10, characterised in that the grinding material to be supplied to the tube mill is first fed to a precomminuting stage (60) and some of the precomminuted material is recirculated to the precomminuting stage.
18. A method according to claim 10, characterised in that the grinding material to be supplied to the tube mill is first fed to a precomminuting stage (60) and the precomminuted material is supplied to a classifying apparatus (62) arranged downstream, the coarse material from which is conducted to the first grinding chamber (1) and/or to the precomminuting stage (60) and the fine material from which passes to the second grinding chamber (2).

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