Preliminary size reduction device for a ball mill or agitator ball mill and ball mill with a preliminary size reduction device

Abstract

A preliminary size reduction device for a ball mill or agitator ball mill and a ball mill with a preliminary size reduction device, wherein the preliminary size reduction device is disposed between a grinding stock inlet of the ball mill or agitator ball mill and a grinding chamber and includes a first size reduction mechanism constituted stationary and a second, rotationally mobile size reduction mechanism, between which a size reduction gap is formed. The first size reduction mechanism constituted stationary is a size reduction ring disposed in the grinding container.

Claims

1. A preliminary size reduction device for a ball mill or agitator ball mill comprising, a first size reduction means being stationary, a second size reduction means being rotationally mobile, a size reduction gap between the first size reduction means and second size reduction means, wherein the preliminary size reduction device is positionable between a grinding stock inlet of the ball mill or agitator ball mill and a grinding chamber, wherein the first size reduction means is a size reduction ring disposable in a grinding container, wherein the first size reduction means comprises an inner toothing system, wherein the second size reduction means comprises a first sub-region and a second sub-region, wherein the second sub-region guides grinding stock in the direction of the first sub-region, wherein the first sub-region of the second size reduction means comprises a first outer toothing system, and wherein the first sub-region of the second size reduction means is constituted as a cylindrical region; wherein the first size reduction means and the second size reduction means are configured in such a way that the outer toothing system of the first sub-region of the second size reduction means engages into the inner toothing system of the first size reduction means, thereby forming the size reduction gap.

2. The preliminary size reduction device according to claim 1, wherein the second size reduction means in the second sub-region comprises a second outer toothing system with second outer teeth, wherein the second outer teeth have a second tooth height and width, which is greater than a first tooth height and width of first outer teeth of the first outer toothing system in the first sub-region of the second size reduction means, and wherein the second outer toothing system guides the grinding stock.

3. The preliminary size reduction device according to claim 2, wherein the tooth width of the second outer teeth increases from a free end of the second sub-region in the direction of the adjacent first sub-region.

4. The preliminary size reduction device according to claim 2 further comprising, a first side and a second side delimiting an outer surface of the second outer teeth have a curved course, wherein the first side has a more marked curvature than the second side.

5. The preliminary size reduction device according to claim 2, wherein the first outer toothing system of the first sub-region of the second size reduction means is continued over outer surfaces of the second outer toothing system of the second sub-region of the second size reduction means.

6. The preliminary size reduction device according to claim 2, wherein the second sub-region of the second size reduction means is constituted in the form of a truncated cone with a truncated cone bottom face and a truncated cone top face, and wherein the first sub-region of the second size reduction means has a cylindrical bottom face, wherein the truncated cone bottom face and the cylindrical bottom face are the same size and wherein the cylindrical region with a cylindrical bottom face lies adjacent to the truncated cone bottom face of the truncated cone region.

7. The preliminary size reduction device according to claim 6, wherein the tooth width of the second outer teeth increases from the truncated cone top face of the truncated cone region in the direction of the cylindrical region.

8. The preliminary size reduction device according to claim 6, wherein the outer toothing system of the cylindrical region of the second size reduction means is continued over the outer surface of the second outer toothing system of the truncated cone region of the second size reduction means.

9. An agitator ball mill comprising: a preliminary size reduction device between a grinding stock inlet of the agitator ball mill and a grinding chamber, wherein the preliminary size reduction device comprises a first size reduction means constituted stationary and a second, rotationally mobile size reduction means, between which a size reduction gap is formed, wherein the first size reduction means constituted stationary is a size reduction ring disposed in the grinding chamber, wherein the first size reduction means constituted stationary comprises an inner toothing system and that the second size reduction means comprises a first sub-region and a second sub-region, wherein the second sub-region comprises guiding structures for grinding stock, by means of which the grinding stock can be guided in the direction of the first sub-region, and wherein at least the first sub-region of the second size reduction means comprises a first outer toothing system, wherein the first sub-region of the second size reduction means is constituted as a cylindrical region, and wherein the first size reduction means and the second size reduction means are disposed in such a way that the outer toothing system of the first sub-region of the second size reduction means engages into the inner toothing system of the first size reduction means, thereby forming the size reduction gap.

10. The ball mill, in particular the agitator ball mill, according to claim 9, wherein the second size reduction means in the second sub-region comprises a second outer toothing system with second outer teeth, wherein the second outer teeth have a second tooth height and width, which is greater than a first tooth height and width of first outer teeth in the first sub-region of the second size reduction means and wherein the second outer toothing system are the guiding structures for the grinding stock.

11. The preliminary size reduction device according to claim 3 further comprising, a first side and a second side delimiting an outer surface of the outer teeth have a curved course, wherein the first side has a more marked curvature.

12. The preliminary size reduction device according to claim 6, wherein the second outer toothing system is in the region of an outer lateral surface between the truncated cone top face and the truncated cone bottom face.

13. A preliminary size reduction device for a ball mill or agitator ball mill comprising; a stationary size reduction ring disposable in a grinding container having an inner toothing system; a second size reduction means being rotationally mobile having a first sub-region having a cylindrical shape with an outer toothing system and a second sub-region; wherein the second sub-region guides grinding stock in the direction of the first sub-region; wherein the inner toothing system of the size reduction ring and the outer toothing system of the first sub-region of the second size reduction means engage to form a size reduction gap; and wherein the preliminary size reduction device is positionable between a grinding stock inlet of the ball mill or agitator ball mill and a grinding chamber.

14. The preliminary size reduction device according to claim 6, wherein the tooth height of the second outer teeth diminishes in the direction of the cylindrical region.

15. The preliminary size reduction device according to claim 2, wherein the tooth height of the second outer teeth diminishes in the direction of the adjacent first sub-region.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Examples of embodiment of the invention and its advantages are explained below in greater detail with the aid of the appended figures. The size ratios of the individual elements with respect to one another in the figures do not always correspond to the actual size ratios, since some forms are represented simplified and other forms are represented enlarged in relation to other elements for the sake of better illustration.

(2) FIG. 1 shows a diagrammatic view of an agitator ball mill with a vertically disposed grinding container and agitator according to the prior art.

(3) FIG. 2 shows a diagrammatic view of an agitator ball mill with a horizontally disposed grinding container and agitator according to the prior art.

(4) FIGS. 3A-3D show various views of a first size reduction means of a preliminary size reduction device according to the invention.

(5) FIGS. 4A-4E show various views of a second size reduction means of a preliminary size reduction device according to the invention.

(6) FIG. 5 shows a detail of the toothing system between the first size reduction means and the second size reduction means.

(7) FIG. 6 shows a cross-section through a preliminary size reduction means according to the invention.

(8) Identical reference numbers are used for identical or identically acting elements of the invention. Furthermore, for the sake of a clearer view, only reference numbers are represented in the individual figures that are required for the description of the respective figure. The represented embodiments only represent examples as to how the device according to the invention or the method according to the invention can be constituted and do not represent a conclusive limitation.

DETAILED DESCRIPTION

(9) FIG. 1 shows a diagrammatic view of an agitator ball mill 1a with a vertically disposed grinding container 2 and an agitator 3 according to the prior art. Agitator ball mill 1a comprises and upper grinding stock inlet 4 and a lower grinding stock outlet 5, to which a separating device 6 is assigned. Separating device 6 holds back the grinding bodies (not represented) in grinding container 2. Agitator ball mill 1a further comprises a preliminary size reduction device 7 connected to agitator shaft 3* of agitator 3. Said preliminary size reduction device comprises a crushing cone 8, which is disposed rotationally fixed on agitator shaft 3*, and a crushing ring 9 fixed to grinding container 2. The grinding stock is introduced into crushing gap S between crushing cone 8 and crushing ring 9 and thereby undergoes preliminary size reduction, before it falls into grinding container 2, in which it is worked further by agitator 3 and the grinding bodies. The ground product is then removed via grinding stock outlet 5 from agitator ball mill 1a.

(10) FIG. 2 shows a diagrammatic view of a further agitator ball mill 1b with a horizontally disposed grinding container 2 and an agitator 3 according to the prior art. Agitator ball mill 1b comprises an upper grinding stock inlet 4 and a grinding stock outlet 5 disposed centrally on the opposite side of grinding container 2, a separating device 6 being assigned to said grinding stock outlet. Separating device 6 holds back grinding bodies M in grinding container 2. Agitator ball mill 1b also comprises a preliminary size reduction device 7 connected to agitator shaft 3*. Said preliminary size reduction device comprises a crushing cone 8, which is disposed rotationally fixed on agitator shaft 3* of agitator 3, and a crushing ring 9 fixed to grinding container 2. The grinding stock is introduced into crushing gap S between crushing cone 8 and crushing ring 9 and thereby undergoes preliminary size reduction before it passes into grinding container 2, in which it is worked further by agitator 3 and grinding bodies M. The ground product is then removed via grinding stock outlet 5 from agitator ball mill 1. Preliminary size reduction device 7 comprises a gap protection to grinding chamber 2R, said gap protection preventing grinding bodies M from being able to flow back and get into preliminary size reduction device 7.

(11) A preliminary size reduction device 7 according to the invention (see in particular FIG. 6) comprises a first size reduction means 20 constituted stationary (see FIGS. 3) and a second, rotationally mobile size reduction means 30 (see FIGS. 4), between which a size reduction gap S is formed. In particular, first size reduction means 20 is constituted as a so-called size reduction ring 21 and second size reduction means 30 is constituted as a so-called elongated truncated cone 31. The preliminary size reduction device is disposed inside the mill between grinding stock inlet 4 and grinding chamber 2R (see also FIGS. 1, 2 and 6), in such a way that second size reduction means 30 on the side facing towards grinding chamber 2R engages at least partially into first size reduction means 20, thereby forming size reduction gap S, so that the grinding stock has to pass through size reduction gap S when it enters into grinding chamber 2R, whereby it undergoes preliminary size reduction.

(12) FIGS. 3 show various views of a first size reduction means 20 of a preliminary size reduction device according to the invention, in particular FIG. 3B represents a cross-section along intersecting line A-A according to FIG. 3A. First size reduction means 20 is constituted in particular as size reduction ring 21. Inner circumferential surface 24 of size reduction ring 21 comprises a so-called inner toothing system comprising inner teeth 26.

(13) FIG. 3C shows a perspective view of first size reduction means 20 constituted as a size reduction ring 21 and FIG. 3D shows a detail from FIG. 3A. In particular, the inner toothing system in inner circumferential surface 24 can clearly be seen here with fine inner teeth 26.

(14) FIGS. 4 show various views of a second size reduction means 30 of a preliminary size reduction device according to the invention, in particular FIG. 4C represents a cross-section along intersecting line A-A according to FIG. 4B. FIG. 4D shows a detail from FIG. 4C. FIG. 4E shows a plan view of second size reduction means 30 onto a top face DF.

(15) Second size reduction means 30 comprises a region constituted as truncated cone 35 and a cylindrical region 34. The region constituted as truncated cone 35 has a bottom face GF, a top face DF and an outer lateral surface AF35. Cylindrical region 34 comprises a cylindrical bottom face ZF with the same cross-section or the same diameter as bottom face GF of truncated cone 35 and an outer lateral surface AF34.

(16) Second size reduction means 30 comprises, at least in sections, first outer teeth 36. Furthermore, second size reduction means 30 comprises, at least in sections, second outer teeth 37. In particular, second size reduction means 30 comprises a first cylindrical region 34, with first teeth 36 having a first material thickness and/or material height and a second truncated cone-like region 35 with first teeth 36 and second teeth 37 having a second material thickness and/or material height and wherein the first material thickness and/or material height is smaller than the second material thickness and/or material height. In particular, the first material thickness and/or material height of fine outer teeth 36 of second size reduction means 30 correspond at least for the most part to the material thickness and/or material height of inner teeth 26 of size reduction ring 21 (see also FIGS. 3).

(17) So-called coarse teeth 37 of second size reduction means 30 are constituted much thicker in the entrance region of preliminary size reduction device 7 than fine teeth 36 of second size reduction means 30 and/or fine inner teeth 26 of first size reduction means 20 or size reduction ring 21. Second coarse teeth 37 in second region 35 of second size reduction means 30 also have a tapering tooth shape. In particular, the tooth shape tapers in the direction of the free end region of second size reduction means 30 facing away from size reduction ring 21 or in the direction of a top face DF of the second region of second size reduction means 30 constituted as truncated cone 35.

(18) According to a preferred embodiment, fine teeth 36 extend over the outer lateral surfaces of coarse outer teeth 37. Coarse particles of the grinding stock can be better picked up and undergo preliminary size reduction as a result of coarser second outer teeth 37 of second size reduction means 30. The overall preliminary size reduction device is constituted and disposed between grinding stock inlet 4 and grinding chamber 2R in such a way (see also FIGS. 2 and 6) that as far as possible no dead space is formed, in order to prevent the jamming of coarse particles and/or impurities due to the grinding stock.

(19) According to an optional embodiment of the invention, the sides delimiting the outer lateral surface of coarse outer teeth 37 have a curved course. In particular, one of the two sides has a more marked curvature, as a result of which the widening of outer teeth 37 in the direction of adjacent cylindrical sub-region 34 is formed.

(20) FIG. 5 shows a detail of the toothing system between first size reduction means 20 and second size reduction means 30, in particular fine inner teeth 26 of size reduction ring 21 and fine outer teeth 36 of cylindrical region 34 of second size reduction means 30. Fine inner teeth 26 and fine outer teeth 36 for the most part engage into one another, thereby forming a size reduction gap S. Size reduction gap S defines a minimum distance between fine inner teeth 26 of size reduction ring 21 and fine outer teeth 36 of cylindrical region 34 of second size reduction means 30, so that the grinding stock entering via size reduction gap S into grinding chamber 2R (see FIGS. 1, 2 and 6) undergoes preliminary size reduction. The combination of a fine toothing system 26, 36 and a coarse toothing system 37, in particular in combination with a tapering tooth shape of coarse toothing system 37, leads to an improved entrance behaviour in the case of coarse product constituents, in particular when the grinding stock comprises product constituents of differing size. In addition, a greater tooth depth is formed on the inlet side by coarse toothing system 37. With the preliminary size reduction device according to the invention, therefore, a better pumping effect and/or turbulence is achieved, which prevents the product from sticking in inlet region 10 (see FIGS. 2 and 6).

(21) The invention has been described by reference to a preferred embodiment. A person skilled in the art can however imagine that modifications or changes to the invention can be made without thereby departing from the scope of protection of the following claims.