EP2871000B1 - Wear protection assembly for an agitator mill - Google Patents

Description

The invention relates to a wear protection arrangement for an agitator mill, in particular an agitator ball mill with an agitator comprising a module body and an agitator for an agitator ball mill.

Agitator ball mills are used for comminuting and homogenizing solid particles, in which auxiliary grinding bodies, which for example consist of steel or wear-resistant ceramic materials, are moved intensively by means of an agitator. The solid particles are crushed by impact, pressure, shear and friction. The auxiliary grinding bodies in a grinding container are activated by the agitator, which can be equipped with agitators such as rods or discs.

The auxiliary grinding bodies used lead to wear, in particular of the grinding container and the agitator. In the past, it was therefore proposed to equip the container wall with wear protection elements, which can be replaced if necessary. For example, is in the laid-open specification DE 10 2011 051 041 A1 discloses an agitator ball mill in which an attachable to the container inner wall wear protection element is arranged with the help of a fastening system, wherein the fastening system consists of a fastening pin and a fastening recess, which are arranged on the container inner wall and / or the back of the wear protection element that the wear protection element by a Movement of the wear protection element in one direction on the container wall can be fastened by inserting the fastening pin into the fastening recess.

The agitator is subject to particularly high wear, since it also serves to activate the auxiliary grinding bodies, so that the agitator must be replaced after a certain operating time of the agitator ball mill, which is associated with considerable expense. In order to reduce costs, it is known from the prior art, for example, to attach the agitator bodies of the agitator to an agitator shaft in an exchangeable manner. So it is in the pamphlet DE 20 2008 006 745 U1 discloses a grinding disk which has an annular body and a plurality of cams, the cams being releasably connected to the annular body. The cams are preferably made of ceramic and can be screwed to the ring body. Advantageously, the agitator bodies should be able to be easily renewed without having to dismantle the ring body by simply detaching individual worn cams from the ring body and replacing them with new cams.

In the DE 199 19 486 A1 A perforated disk agitator for an agitator ball mill is disclosed, which has a modular structure, a module consisting of a two-part sleeve and a stirring body designed as a stirring disk, which is inclined at a predetermined angle to the sleeve axis and is pushed onto the sleeve. The agitator disk has a central plug-on hole for this purpose. Several identical modules are pushed onto the sleeve and clamped axially. DD 272 805 A1 discloses a wear protection arrangement for an agitator mill according to the preamble of claim 1.

However, it would be desirable to provide an agitator ball mill with a wear protection arrangement which not only counteracts the wear of the agitator bodies, but also prevents other components of the agitator coming into contact with the ground material to be processed and the auxiliary grinding bodies from excessive wear and at the same time also effectively protects the contact points between the individual modules, the support and fastening means from the ingress of ground material and auxiliary grinding bodies. The known solutions of the type mentioned above are only inadequately suitable for such wear protection.

The invention is therefore based on the object of specifying a wear protection arrangement of the type mentioned at the outset, with which an effective wear protection of the entire modular agitator is made possible.

The object is achieved according to the invention by a wear protection arrangement according to claim 1.

The invention is based on the idea that the fastening means for the module body of the agitator should be protected against excessive wear as they are usually in direct contact with the material to be ground and the auxiliary grinding bodies. Furthermore, the penetration of ground material and auxiliary grinding bodies into the contact spaces of the modular agitator should be prevented, as otherwise wear and tear can occur in these areas and the dismantling of the agitator or the replacement of agitators is made more difficult.

This is achieved in that a sealant is preferably assigned to each contact area of the agitator. The module bodies are axial by means of the clamping device braced, wherein the clamping device can consist of a comparatively wear-prone material, since it is protected by a cover made of preferably wear-resistant material. Furthermore, the module bodies can be designed wholly or partially as agitator bodies and arranged in the circumference of the agitator so that they protrude into the grinding chamber. To clamp the module body, the agitator shaft is provided with a grinding disk on at least one end section. The grinding disk is preferably formed from a wear-resistant material, in particular a ceramic grinding disk.

To simplify the assembly or disassembly of the grinding disk, it can also consist of several parts which are detachably connected to the agitator shaft. The disk segments should be designed and arranged on the agitator shaft in such a way that a transition area to an adjacent disk segment lies outside a fastening area of the disk segment and agitator shaft. Thus, in particular, a sealant is not required between the individual disk segments, since the transition area is not in contact with a part of the agitator shaft which should be protected from wear.

Each disk segment is preferably designed as a stirring body or at least one disk segment has stirring bodies. This makes it possible, in the event of wear or, for example, damage during assembly or disassembly of the agitator shaft, to replace only individual disk segments instead of the entire grinding disk, which represents a considerable saving in costs.

The individual disk segments are preferably formed according to dividing lines which run from the center of the disk radially outward but not through the fastening area to be sealed and which define the transition area. This gives the disc segments in Transition area has a conical shape, as a result of which the stability of the agitator shaft compared to a agitator shaft with a one-piece grinding disk is not changed or is only negligibly disadvantageous.

Another advantage of the divided grinding disc is that differences in the dimensions of the individual module bodies can be better compensated for. In particular, any positional tolerances of the disk segments on the agitator shaft in the fastening area can be compensated for. In addition, this ensures an effective seal in the fastening area.

The module bodies are preferably arranged on a support frame of the agitator and spacer bodies are introduced between the agitator bodies. For this purpose, the support frame has receiving parts for the module and spacer bodies. In the case of a divided embodiment of the grinding disk, the number of disk segments preferably corresponds to the number of receiving parts. However, it is also conceivable that more than one receiving part is assigned to a disk segment. The sealing means in the area of the contact points preferably act close to the ground material in order to also prevent contamination and wear in the edge areas of the intermediate spaces as far as possible.

The clamping device further preferably comprises a clamping body and at least one fastening means assigned to it. The clamping body can be formed from a different material than that of the grinding disk. The clamping body is advantageously made of a metallic material such as steel. The clamping of the module body thus takes place via this clamping body, which has a relatively high elasticity and low brittleness compared to the grinding disk. The forces acting on the grinding disc during clamping are advantageously distributed over a surface and thus prevent, for example, cracking through the fastening means.

The clamping device is preferably releasably attached to the agitator. When the agitator is dismantled, for example to replace individual module bodies, the clamping device is not destroyed and can be reused. Fasteners are proposed with which a screw connection can be established.

The clamping device and / or the protective body are particularly preferably designed in the form of a ring. The distribution of forces when the module bodies are braced onto the grinding disk is thus evenly carried out, so that the risk of failure of the agitator ball mill, for example due to the formation of cracks or destruction of the module body, can be further reduced. The protection of the entire clamping body is made possible by a likewise annular design of the protective body.

In a preferred development, the clamping device has a shape that corresponds to the protective body. As a result, the clamping device is effectively enclosed by the protective body. The protective body is preferably designed as a U-profile so that the clamping device can be received by the protective body.

In order to achieve a seal between the module bodies, the clamping device and the protective body, it is proposed to use sealing elements serving as sealing means. This creates a detachable contact area that is protected from the ingress of ground material and auxiliary grinding bodies, the sealing means being reusable.

The sealing elements are preferably sealing rings, as a result of which advantageous, uninterrupted sealing surfaces are formed and can be sealed both radially and axially. For example, the receiving parts of the agitator frame for the module body can be guided through the sealing rings. As a result, the receiving part can also be sealed. In order to further improve the seal, at least two sealing elements are preferably assigned to each module body and the clamping device.

According to a preferred development, the module body, the protective body and / or the clamping device have a recess that receives the sealing element. It is thereby achieved that, on the one hand, the sealing effect is improved due to the enlarged sealing surface and, on the other hand, the sealing element always runs along a predetermined sealing line of an area to be sealed.

The advantages achieved with the invention are, in particular, that the entire agitator is sealed off from the material to be ground and the auxiliary grinding bodies. In particular, contact of the agitator frame and the clamping device with the mixture of ground material and auxiliary grinding bodies can be effectively prevented, so that these components are protected from destruction. Even with a grinding process using relatively small auxiliary grinding bodies, these cannot penetrate into the spaces or gaps in the agitator and cause damage.

Fig. 1

schematisch eine aus dem Stand der Technik bekannte Rührwerkskugelmühle,

Fig. 2

schematisch ein Modulkörper, eine Klemmeinrichtung und ein Schutzkörper enthaltendes Rührwerk für eine Rührwerkskugelmühle,

Fig. 3

einen vergrößert dargestellten Endabschnitt des Rührwerks mit Befestigungsmittel für einen Klemmkörper der Klemmeinrichtung,

Fig. 4

einen vergrößert dargestellten Endabschnitt des Rührwerks mit Befestigungsmittel für den Schutzkörper,

Fig. 5

schematisch eine aus Scheibensegmenten gebildete Mahlscheibe mit Ausnehmungen für Aufnahmeteile im Befestigungsbereich.

Embodiments of the present invention are explained by way of example with reference to the attached drawings. Show in it:

Fig. 1

schematically an agitator ball mill known from the prior art,

Fig. 2

schematically a module body, a clamping device and an agitator containing a protective body for an agitator ball mill,

Fig. 3

an enlarged end section of the agitator with fastening means for a clamping body of the clamping device,

Fig. 4

an enlarged end section of the agitator with fastening means for the protective body,

Fig. 5

schematically a grinding disk formed from disk segments with recesses for receiving parts in the fastening area.

The same parts are provided with the same reference symbols in all figures.

Fig. 1 shows schematically the structure of a known agitator ball mill 2 with a separating device 4. The agitator ball mill 2 shown comprises a grinding container 6 which is provided with a grinding material inlet 8 and a grinding material outlet 10. An agitator designed as an agitator shaft 12 is arranged centrally in the grinding container 6. The agitator shaft 12 is provided with pin-like agitator bodies 14 which protrude into a grinding chamber 16. The separating device 4 is arranged within the agitator shaft 12. When the mill 2 is in operation, the medium to be ground is supplied via the grinding material inlet 8 and transported in the direction of the grinding material outlet 10. In the grinding chamber 16, between the agitator shaft 12 and the grinding container 6, there are auxiliary grinding bodies (not shown). The mixture of ground material and auxiliary grinding body is separated with the aid of the separating device 4 in the end region of the mill 2, so that only the ground material is separated Grist outlet 10 passes, whereas the auxiliary grinding bodies are transported back into the grinding chamber 16 via a recess 18 in the agitator shaft 12.

One across from the Fig. 1 The modular agitator shaft 12 according to the invention, shown enlarged, is shown in FIG Fig. 2 shown. A frame for receiving the module bodies 20 is mounted on a base body 24 of the agitator shaft 12 via a holding plate 22. Axially extending receiving parts 26 for the module bodies 20 are arranged on the holding plate 22, distributed over the circumference. The module bodies 20 are alternately pushed onto the receiving parts 26 as stirring bodies 14 and spacer bodies 28. Finally, the agitator shaft 12 is provided with a module body designed as a grinding disk 30, the module bodies 20 being clamped together with the aid of a clamping device 32, formed by a clamping body designed as a clamping ring 34 and a screw connection 36a as fastening means.

The module body 20 consists of a wear-resistant ceramic material. The clamping ring 34 is designed as a metallic ring. The arrangement and dimensions of the receiving parts 26 and the module body 20 are selected such that, as in analogy in FIG Fig. 1 shown, axially extending recesses 18 arise through which the grinding material and auxiliary grinding bodies can flow during a grinding process. In the agitator ball mill 2, this end section of the agitator shaft 12 encloses the separating device 4 in a cage-like manner.

In order to also protect the clamping ring 34 from wear, it is completely enclosed on its outside by a protective body in the form of a U-shaped protective ring 38. The protective ring 38 is fastened to the clamping ring 34 by means of screw connections 36b and for this purpose has the front face in the circumference distributed recesses 40 on. The recesses 40 are closed by a wear-resistant cover 42.

Sealing rings 44, which are pushed onto the receiving parts 26, are arranged as sealing means between the module bodies 20. Even if ground material or auxiliary grinding bodies should penetrate through a defective seal or a defective module body, further axial penetration is prevented due to the sealing rings 44 arranged in modules, and the agitator shaft 12 is protected from wear. In each case a further sealing ring (not shown here) with a larger diameter can be arranged between them near the grinding chamber 16 for additional sealing of the module bodies 20.

To accommodate the sealing rings 44, the module bodies 20 and the clamping ring 34 have recesses 46 that correspond to the embodiment and cross-sectional shape of the sealing rings 44. In the in Fig. 2 In the embodiment shown, recesses 46 running in a ring shape for the sealing rings 44 are introduced on both sides of the stirring body 14 and spacer body 28. The clamping ring 34 also has recesses 46, namely for sealing against the grinding disk 30 and towards the inner surfaces of the U-shaped protective ring 38. In the area of the fastening means 36b for the protective ring 38, around the fastening means 36b, there are annular recesses 46 in the clamping ring 34 introduced.

Figs. 3 and 4 show an enlarged end section of the agitator shaft 12, the section in FIG Fig. 3 the type of fastening of the clamping ring 34 to the receiving part 26 for the module body 20 and Fig. 4 that of the protective ring 38 on the clamping ring 34 is intended to illustrate. The clamping ring 34 is detachably connected to the receiving part 26 with the aid of a cylinder head screw 48 and an axially extending threaded hole in the receiving part 26.

The protective ring 38 is also releasably fastened in the clamping ring 34 by means of a cylinder head screw 48 and a threaded hole. To protect the screw head countersunk in the recess 40, which is open towards the grinding chamber 16, the recess 40 is provided with the closure arrangement 42 made of wear-resistant material, which also serves as a seal.

A grinding disk 30 formed from disk segments 50 with corresponding recesses 52 for receiving parts in the fastening area 54 is shown in FIG Fig. 5 shown. For simple assembly or disassembly of the grinding disk 30, it consists of several parts which can be detachably connected to the agitator shaft. The disk segments 50 are designed in such a way that a transition area 56 to an adjacent disk segment 50 lies outside the fastening area 54.

Each disk segment 50 is designed as a stirring body. The individual disk segments 50 are formed in accordance with the dividing lines 58, which run radially outward from the center of the disk 30 but not through the fastening area 54 and define the transition area 56 of adjacent disk segments 50. As a result, the disk segments 50 have a conical shape in the transition region 56.

The number of disk segments 50 corresponds to the number of receiving parts (not shown here), since each disk segment 50 is provided with a recess 52 for a receiving part of the agitator shaft.

The wear protection arrangement is specifically designed to protect the entire agitator shaft 12. The sealing according to the invention of the parts of the agitator shaft 12 relevant to the modular design effectively prevents the material to be ground or auxiliary grinding bodies from wearing out the agitator shaft 12 and thus the The operational safety of the mill 2 is endangered. In addition, module bodies 20, in particular, can be easily exchanged, since they can be easily detached and assembled because of the protected receiving areas of the agitator shaft 12 and protected areas between the module bodies 2.

List of reference symbols

02

Agitator ball mill

04

Separator

06

Grinding container

08

Regrind inlet

10

Regrind outlet

12th

Agitator shaft

14th

Agitator

16

Grinding room

18th

Stirrer shaft recess

20th

Module body

22nd

Retaining plate

24

Base body

26th

Receiving part

28

Spacer body

30th

Grinding disc

32

Clamping device

34

Clamping ring

36a, b

Screw connection

38

Guard ring

40

Protective ring recesses

42

Locking arrangement

44

Sealing rings

46

Recesses for sealing rings

48

Cylinderhead screw

50

Disc segment

52

Recess for receiving part

54

Attachment area

56

Transition area

58

parting line

Claims (11)

1. A wear protection assembly for an agitator mill, in particular an agitator ball mill (2) with an agitator (12) comprising module bodies (20), which agitator is provided at at least one end portion on the face side with a module body (20) forming a grinding disk (30), and the module bodies (20) are arranged in an axially clamped manner by means of a clamping means (32), characterized in that, for a wear protection, the clamping means (32) is provided with a protective body (38) as cover, and sealing means (44) are assigned to the module bodies (20), the clamping means (32), and the protective body (38).
2. The wear protection assembly according to claim 1, wherein the clamping means (32) comprises a clamping body (34) and at least one fastening element (48).
3. The wear protection assembly according to claim 1 or 2, in the case of which the clamping means (32) is releasably fastened to the agitator (12).
4. The wear protection assembly according to claim 1 to 3, wherein the clamping means (32) and/or the protective body (38) are formed annularly.
5. The wear protection assembly according to claim 1 to 4, in the case of which the clamping means (32) has a shape that corresponds to the protective body (38).
6. The wear protection assembly according to claim 1 to 5, wherein the sealing means are formed as sealing elements (44) .
7. The wear protection assembly according to claim 6, wherein the sealing element is formed as sealing ring (44).
8. The wear protection assembly according to claim 6 or 7, wherein at least two sealing elements (44) are assigned to each module body (20) and the clamping means (32).
9. The wear protection assembly according to claim 6 to 8, wherein the module bodies (20), the protective body (38) and/or the clamping means (32) have a recess (46) accommodating the sealing element (44).
10. The wear protection assembly according to claim 1 to 9 with an annular protective body (38) formed as U-profile.
11. An agitator (12) for an agitator ball mill (2) with a wear protection assembly according to claim 1 to 10.

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