Agitator mill having special drivers

Abstract

The invention relates to an agitator mill (1), in particular in the form of a full-volume disc mill, having a grinding container (2) and an agitator shaft (3) which rotates therein about a horizontal axis (6) and supports a plurality of grinding discs (4) which are connected to this shaft for conjoint rotation and are spaced apart from one another in the direction of the horizontal axis (6), the grinding discs (4) each having slots or openings, characterised in that, in the region between two grinding discs (4), the agitator mill (1) has drivers which rotate synchronously with the grinding discs (4) during grinding and which impart a movement component in the radially outwards direction to at least some of the grinding bodies coming into contact with these discs, by directly moving these grinding bodies as they rotate, preferably in the radial direction.

Description

[0001] AGITATOR MILL WITH SPECIAL CARRIERS

[0002] The invention relates to an agitator mill with drivers according to the preamble of claim 1.

[0003] TECHNICAL BACKGROUND

[0004] The basic principle of a stirred mill will first be explained using Fig. 1.

[0005] Fig. 1 schematically shows an agitator mill 1 with a horizontal agitator shaft 3. The grinding media located in the grinding vessel 2, which are usually made of steel or ceramic balls, have been omitted.

[0006] During operation of the agitator mill 1, the material to be ground is pumped via the inlet 101 of the agitator mill 1 into or through the grinding chamber 14 enclosed by the grinding container 2. In the case of wet grinding, the material to be ground is a suspension or dispersion of a liquid, usually in the form of water, and solids. In other cases, such a agitator mill 1 can also be used for dry grinding. It can then be designed, for example, as an agitator mill with a vertical shaft through which the material to be ground is carried by a gaseous fluid, usually in a downdraft.

[0007] In its broadest aspect, the present invention relates to both types of agitator mills. Its use is particularly preferred for agitator mills with a horizontal agitator shaft 3.

[0008] A rotational movement of the agitator shaft 3 about the agitator shaft axis 6 sets the grinding elements, which are connected to the agitator shaft 3 in a rotationally fixed manner and are frequently also designed and referred to as grinding discs 4, in rotation. Likewise possible, also within the scope of the invention to be described shortly, is the design of the grinding elements in the form of individual pins. However, the use of grinding discs is preferred within the scope of the invention, which is why only "grinding discs" are referred to below, and only such grinding discs are shown as grinding elements. To generate the rotational movement, the agitator shaft 3 can be driven by an electric motor, for example, via a belt drive. The drive of the agitator mill 1 is usually located in a housing adjacent to the grinding container 2. The drive and the housing are not shown in Fig. 1 for the sake of clarity.

[0009] Due to the rotation of the grinding discs 4, the grinding media located in the grinding chamber 14, which are located near the grinding discs 4, are carried along in the circumferential direction of the grinding container 2. In the central region between each two grinding discs 4, the moving grinding media flow back towards the agitator shaft 3 as soon as they have reached the apex region. This creates a circulating movement of the grinding media between each two grinding elements or grinding discs 4. This circulating movement is illustrated schematically in Fig. 1 by means of two dashed arrows (dash-two-dot line) as an example for the free space between the first and second grinding discs 4 (seen from the inlet 101 and only in the upper area of ​​the sectional view of the agitator mill 1).

[0010] The movement of the grinding media causes collisions and rolling over between the solids in the grinding material suspension pumped through the grinding container 2 and the grinding media. These collisions and rolling over lead to the splintering of fine particles from the solids in the grinding material suspension, so that the solids arriving at the outlet 102 of the agitator mill 1 are ultimately significantly smaller than the solids fed in at the inlet 101.

[0011] To ensure that grinding media are not discharged from the grinding chamber 14, a sieve 103 is usually mounted in front of the outlet 102 and / or supported by the outlet 102. A basket 104 enclosing this sieve 103 is mounted around it. The basket serves to prevent the grinding media, which tend to be pushed toward the sieve by the pressure of the feed pump, from exerting undesirable grinding media pressure on the sieve.

[0012] Such agitator mills, and in particular full-space disc mills, as shown in Fig. 1, are characterized by the fact that voluminous free spaces are formed between the immediately adjacent grinding discs 4, which – as mentioned – are essentially filled with grinding media. Such a full-space disc mill exists in particular when grinding discs are used as grinding elements and when the inner diameter D B of the grinding container 2 is equal to or greater than 2.5 times the diameter D W the agitator shaft 3. As diameter D W is understood here as the outer diameter of the agitator shaft 3 in the area between two adjacent grinding discs 4.

[0013] Due to the corresponding packing density, the grinding media essentially remain in their area between two grinding discs 4, even if gaps or openings are encountered which, by their nature, would allow a grinding media to pass from one area between two grinding discs 4 to an adjacent area between two grinding discs 4. A fluid is pumped through the spaces between the grinding media from the inlet 101 of the agitator mill 1 to its outlet 102. A feed pump is used for this purpose. The feed pump flow of this fluid carries the material to be ground through the agitator mill 1.

[0014] The grinding media are driven along by the friction on the grinding discs 4 when rotating along the agitator shaft 1 and the grinding discs 4 connected to it. As mentioned, they therefore rotate in the circumferential direction. In doing so, they roll against each other, on the grinding container 2 and on the grinding discs 4. It is primarily the impulse effect of the grinding media moving towards each other and then colliding with each other, and the aforementioned grinding effect, that creates the

[0015] The material to be ground is crushed, i.e. ground.

[0016] PROBLEM STATEMENT

[0017] The problem that arises time and again is that the grinding bodies do not move dynamically enough in the free space between the two adjacent grinding disks 4 or do not move sufficiently strongly in the radial vicinity of the agitator shaft 3, in which the feed pump attempts to form a cross-flow, and / or the circulating movement of the grinding bodies does not reach close enough to the radial vicinity of the agitator shaft 3.

[0018] This then results in the fluid coming from the feed pump, which carries the material to be ground, traversing one free space between two adjacent grinding discs 4 after the other via the shortest possible path, instead of first circulating gradually for a while in each free space between two grinding discs 4. This then results in a so-called "shot-through" phenomenon. During a shot-through, the material to be ground does not have sufficiently intensive contact with the grinding media. It is therefore only inadequately ground. The schematic movement of the material to be ground during such a "shot-through" phenomenon is again schematically illustrated in Fig. 1 by means of a curved arrow, illustrating the movement from the inlet 101 across the free space between the first and second grinding discs 4 (seen from the inlet 101 and only in the upper area of ​​the sectional view of the agitator mill 1).

[0019] The problem of through-shot is particularly precarious in full-space disc mills, since in such agitator mills the high free space between two adjacent grinding discs 4 tends to a particular extent not to generate sufficient grinding media movement.

[0020] THE UNDERLYING TASK

[0021] In light of the above, the task is to create a stirred mill with further improved grinding efficiency.

[0022] THE INVENTIVE SOLUTION

[0023] According to the invention, this problem is solved with the features of the first main claim.

[0024] For this purpose, an agitator mill, in particular in the form of a full-space disc mill, is proposed, comprising a grinding container and an agitator shaft rotating therein around a horizontal axis. The agitator shaft carries several grinding discs connected to it in a rotationally fixed manner and spaced apart from one another in the direction of the horizontal axis, wherein the grinding discs each have slots or openings. As already explained at the beginning, such a full-space disc mill exists in any case when grinding discs are used as grinding elements and when the inner diameter D B of the grinding container is equal to or greater than 2.5 times the diameter D W of the agitator shaft. Diameter D W Here, the outer diameter of the agitator shaft in the area between two adjacent grinding discs is understood.

[0025] The agitator mill according to the invention is characterized in that it has drivers in the area between two directly adjacent grinding discs, which rotate synchronously with the grinding discs during grinding. In addition, these drivers impart a movement component in a predominantly or substantially radially outward direction to at least some of the grinding bodies that come into contact with them by directly displacing these grinding bodies as they rotate, preferably in a predominantly or substantially radial direction. Thus, the locally caused movement vector of a grinding body after collision with the driver has a movement component in a radially outward direction that accounts for at least 60%, preferably at least 75%, of the entire movement vector. However, it should be explicitly pointed out again that this does not apply to every grinding body after a collision with the driver, but only to at least some of them.The number of grinding media that actually collide with the carrier depends on many factors, such as the design of the carrier, the conveying speed, the size of the grinding media, the material being ground, etc. In general, a pulse is preferentially transmitted to the respective grinding media, which causes the respective grinding media to in turn transmit a pulse to at least one grinding media that comes into contact with the respective grinding media. This grinding media then also transmits a pulse to the grinding media that collide with it. This creates a pulse chain of grinding media, the origin of which lies in the pulse transmission from the carrier to the grinding media that come into contact with the carrier.

[0026] This resulting movement component for at least some of the grinding media, primarily in the radially outward direction, leads to improved circulation of the grinding media. Furthermore, the grinding media in the vicinity of the agitator shaft are also activated, bringing the described circulating movement of the grinding media closer to the rotating surface of the agitator shaft.

[0027] In general, this increases the effective grinding space used for grinding and / or increases the grinding effect on the material to be ground. Furthermore, the number of passes is reduced, as increased movement of the grinding media throughout the entire grinding space radially outside the agitator shaft is ensured, resulting in improved entrainment of the material to be ground.

[0028] PREFERRED TRAINING

[0029] There are a number of possibilities for configuring the invention to further improve its effectiveness or usability. A particularly preferred embodiment consists in a driver having at least one section with a non-circular surface profile—relative to the horizontal axis of the agitator shaft—which forms a pulse generator through which the grinding media are displaced as the driver rotates. This "non-circular surface profile" is preferably achieved by providing a plurality of flattened portions on the driver. These are preferably designed to at least partially flatten an otherwise round cross-section in the region of its circumference. It should be noted here that a driver can also be designed such that, at least in some sections, so many flattened portions are applied over the circumference of a driver that the respective cross-sections no longer have any rounded areas at all.These flattened surfaces are preferably designed as flat surfaces and can also be configured so that they run parallel to the longitudinal axis of the driver and thus to the agitator shaft axis, or even have a certain angle of incidence relative to the longitudinal axis of the driver. The flattened surfaces of a bushing thus effectively act as pulse generators and are subject to only reduced inherent wear. It should also be noted in general that not every section with a "non-circular surface profile" must also function as a pulse generator.

[0030] Furthermore, it is particularly preferred that the drivers are bushings that overlap the agitator shaft in the free area between the grinding discs, or are formed integrally by the agitator shaft in this area, or are an integral component that projects from the front of at least one grinding disc, with a single bushing in the sense of one of the aforementioned alternatives preferably being located between two immediately adjacent grinding discs. This ensures that the drivers can be attached to their intended position between the grinding discs in a simple manner (easy to install and without great manufacturing effort). The preferred embodiment of the driver is preferably in the form of an external bushing that encloses the agitator shaft at least in the area between two adjacent grinding discs.Since this embodiment is clearly the preferred one, we will only refer to drivers in the form of a bushing in the following, which is why we will only use the term "bush". However, it should be emphasized that drivers in other embodiments can also have such design features, which are mentioned below. However, since the bushing shape is clearly the preferred embodiment, it will be referred to below as a "bush" for the sake of simplicity as "drivers, preferably in the form of a bushing".

[0031] A further preferred embodiment consists in that bushings each have the initial shape of a body with a polygonal cross-section, preferably with a square cross-section, which has at least in sections a waist between its end faces, the cross-section of which has a smaller circumference than the polygonal cross-section of the initial shape.

[0032] On the one hand, this has manufacturing advantages, as it is preferred that the bushings represent polygonal bodies that are partially turned. Furthermore, the aforementioned "non-circular surface contours" or flattenings on the bushings can be easily provided. For example, an area from the respective end face of the bushing up to a designated circumferential reduction can be retained without machining the bushing, which then, due to its "angular", polygonal basic shape, already integrally forms various pulse generators. The aforementioned waist is also provided on the bushing so that the grinding media can reach closer to the original agitator shaft. This further enlarges the grinding chamber and - as described at the beginning - a desired circulating movement of the grinding media can develop over a large area up to the vicinity of the agitator shaft surface.

[0033] Furthermore, this waist offers various advantages, especially in combination with the flattened areas mentioned above. The flattened surfaces that extend beyond the waist into the larger-diameter edge areas have a special scooping effect.

[0034] Furthermore, it is particularly preferred if the cross-section of the waist is at least predominantly circular, preferably with a diameter that remains constant over the length of the waist. This is easier to manufacture and, since the agitator shaft preferably also has a circular cross-section, it can be ensured that the grinding media can be brought equally close to the agitator shaft surface over the entire circumference of the bushing. In addition, the design of the waist has a decisive influence on the flow behavior of the grinding media. For example, in a circular design, the waist leads to almost no impulse effect radially outwards. This means that there are no significant counter-movements to the desired grinding media movement towards the shaft axis and the gyratory movement of the grinding media in the middle between two grinding disks towards the bushing is not slowed down.This allows the grinding media to flow unhindered even into the area near the shaft, and prevents any media-free space from forming near the shaft. This generally results in fewer shot-throughs.

[0035] Furthermore, it is particularly preferred if the transitions between the respective end faces and / or end face sections and the waist are chamfered, preferably conical or spherical. This encourages the grinding media circulating in the area between the grinding discs to flow toward the shaft axis, i.e., for example, to move more strongly toward the center between two grinding discs during their downward movement, which intensifies the circulating of the grinding media in the free area between two grinding discs.

[0036] A "front section" is present when - as already mentioned - the initial cross-section of the front side is retained in sections up to a certain circumferential reduction towards the center of the bushing.

[0037] A further preferred embodiment consists in the waist of the bushings being bordered by a surface opposite the pulse generators, which is curved in such a way that it does not form a pulse generator even when the bushing rotates. Thus, the ratio of the area of ​​the waist to the area of ​​the pulse generator can be used to adjust the "shovel effect" of the bushing, i.e., the intensity of the pulse generator formed by this bushing, or how strongly it displaces the grinding media.

[0038] Furthermore, it is particularly preferred that the bushings have inclined surfaces in the region of their waist, preferably in the transition area between the waist and the end face and / or between the waist and the end face section, which are designed in such a way that the grinding media are forced to move predominantly or substantially in the circumferential direction of the agitator shaft, precisely through the rotation of the bushings. Thus, the grinding media, coming from the center between two grinding discs, are deflected toward the grinding disc near the shaft and then moved radially outward by the inclined surfaces toward the grinding disc wall in order to support the "friction conveyance" of the grinding disc wall and to accelerate the grinding media there. The grinding media are thereby increasingly caused to orbit in the area of ​​the free space between two immediately adjacent grinding discs and / or to rotate around themselves, which in each case increases the grinding effect.

[0039] Furthermore, it is particularly preferred if the waist of the bushings is free, i.e., completely free or essentially free, of impulse generators. This allows for a controlled influence on the "blade effect" of the bushings. Even if the respective waist is cut by the flattened portions, the impulse-generating effect of the section in the waist area is negligibly small compared to the impulse generators.

[0040] A further preferred embodiment consists in the fact that the pulse generators are arranged predominantly or even completely, namely absolutely completely or essentially completely, in the vicinity of the grinding disc faces. Preferably, said vicinity is less than or equal to 1 / 4 of the distance between two immediately adjacent grinding discs—measured in the direction of the horizontal axis of the agitator shaft. This achieves a preferential circulating movement of the grinding media.

[0041] Furthermore, it is particularly preferred if the grinding discs have at least one, preferably several, openings through which the grinding media can pass from one space between two grinding discs into the adjacent space between two grinding discs. An opening can be a window with borders on all sides or a slot extending inward from the largest outer radius. These openings allow the material to be ground to pass from the inlet to the outlet of the agitator mill.

[0042] A further preferred embodiment consists in the provision of baffles arranged between the grinding discs, which extend from the inner surface of the grinding vessel into the free space between two grinding discs, preferably directly above the waist of the bushings, ideally in the region of their center. These baffles are usually pins, which are ideally arranged in a line one behind the other in the circumferential direction, so that they do not, or only minimally, slow down the rotation of the grinding media in the circumferential direction.

[0043] Furthermore, it is possible for the baffles to be arranged asymmetrically—preferably in the circumferential direction—i.e., in the space between two immediately adjacent grinding discs, they are located closer to one grinding disc than to the other. Otherwise, the above applies. Generally, the baffles and their described arrangement, depending on the shape of the bushing, lead to preferential flow of the grinding media in the area between two adjacent grinding discs. Thus, the baffles cause a "loosening" of the ball pack formed by the grinding media. This "ball pack" tends to condense against the container wall due to the centrifugal force of the rotating agitator shaft. Such a dense ball pack moves only slowly and thus offers little collision energy for grinding. The baffles loosen the ball pack accordingly, and this loosening further accelerates the centrifugal motion of the grinding media.

[0044] LIST OF FIGURES

[0045] Fig. 1 shows a state-of-the-art agitator mill in a sectional side view, schematically showing the grinding media flow (arrows with a two-dotted line) and the flow of the material to be ground (curved arrow with a solid line).

[0046] Fig. 2 shows, analogous to Fig. 1, a stirred mill according to the invention in a sectional side view with a first embodiment of the bushings and resulting grinding media flow (arrows with dashed two-dot line).

[0047] Fig. 3 shows, analogously to Fig. 2, a stirred mill according to the invention in a sectional side view with a second embodiment of the bushings and resulting grinding media flow (arrows with dashed two-dot line).

[0048] Fig. 4 shows the second embodiment of a socket according to the invention from Fig. 3 in a three-dimensional view.

[0049] Fig. 5a shows a third embodiment of a socket according to the invention in side view and Fig. 5b shows the three-dimensional view of this embodiment.

[0050] Fig. 6a shows a fourth embodiment of a socket according to the invention in a three-dimensional view, Fig. 6b shows this embodiment in a front view, and Fig. 6c shows this embodiment in a side view. Fig. 7a shows a fifth embodiment of a socket according to the invention in a three-dimensional view, Fig. 7b shows this embodiment in a front view, and Fig. 7c shows this embodiment in a side view.

[0051] Fig. 8a shows a sixth embodiment of a socket according to the invention in a three-dimensional view, Fig. 8b shows this embodiment in a front view and Fig. 8c shows this embodiment in a side view.

[0052] PREFERRED EMBODIMENTS

[0053] First, Fig. 1 shows the state of the art, which was already described in more detail in the "Technical Background" section. For this reason, Fig. 1 will not be explained in more detail here. However, it should be pointed out again that with an agitator mill 1 designed in this way, the desired mixing of the grinding media in the area between two adjacent grinding disks 4 does not occur. Although the grinding media perform a desired circulating movement (see arrows with dashed two-dot lines), this circulating movement is not dynamic enough and does not reach into the vicinity of the agitator shaft 3, which is why "shoot-throughs" occur primarily in this area.This means that the material to be ground does not remain long enough in the area between two adjacent grinding discs 4 and does not or only partially complete the circulating movement, thus not experiencing the desired grinding effect before it "shoots through" openings in the grinding disc 4 directly into the adjacent area between two grinding discs 4. For simplification, the respective space between two adjacent grinding discs 4 is hereinafter referred to simply as the "grinding chamber," whereby these "grinding chambers" are thus part of the entire grinding chamber 14.

[0054] Analogous to Fig. 1, Fig. 2 now shows an agitator mill 1 according to the invention with carriers configured according to the invention. Here, too, the grinding media and the material to be ground, as well as the driving parts of the agitator mill 1, have been omitted for clarity.

[0055] Here and in the other figures, the drivers are designed as bushings 8, which enclose the agitator shaft 3 at least between two adjacent grinding discs 4 and are preferably pushed onto shoulders of the agitator shaft. The agitator shaft 3 is thus preferably completely enclosed by the bushings 8 in these areas. In this and all other figures, the drivers are shown in the form of bushings 8, which, for simplicity, are referred to simply as "bushes" below. The exact design of these bushings 8 will be discussed in more detail later.

[0056] In Fig. 2, the arrangement of the bushings 8 between the grinding discs 4 and the formation of the grinding chamber radially outside the bushings 8 can be seen. Furthermore, the circulating movement of the grinding media (arrows with a dashed two-dot line) is shown schematically in a grinding chamber, again by way of example. This is significantly more dynamic (not shown) than the circulating movement in Fig. 1, but above all, this circulating movement runs closer to the surface of the bushing 8 – compared to the equivalent agitator shaft surface in Fig. 1.

[0057] In particular, together with the flow breakers 12, which are designed as radially inwardly projecting projections and are preferably in the form of pins that are periodically attached to the inner wall of the grinding container 2, a desired, dynamic circulation movement of the grinding bodies is formed.

[0058] This results in fewer shots through the grinding material, as the material to be ground remains in the respective grinding chamber longer and is more likely to be entrained by this circulation. This allows for an additional grinding effect on the material to be ground. This is indicated schematically by the material flow (three curved, solid arrows leading from inlet 101 into the respective grinding chamber).

[0059] This desired circulating movement is achieved primarily by imparting a radially outward motion component to the grinding media that collide with the pulse generators 7 of the bushing 8, by directly displacing these grinding media during their rotation, preferably in a radial direction. These pulse generators 7 and the individual sections of the bushings 8 will be discussed in more detail later.

[0060] Analogous to Fig. 2, Fig. 3 shows the same view of a stirred mill 1, but with a second embodiment of the bushings 8. Everything here is analogous to the stirred mill 1 in Fig. 2. The circulating movement of the grinding media is again represented here by arrows with dashed two-dot lines. Furthermore, it can be seen here that the grinding media are forced over the waist 9 or the transitions 13 adjoining the waist 9 toward the pulse generators 7. Figure 3 also shows flow arrows of the material to be ground, which has a tendency to "shoot through" close to the wave, i.e., to skip a grinding chamber in an unground or undesirably finely ground state. Here, it is clear that certain parts of the material to be ground are mixed into the gyratory movement of the grinding media, but also that various shot-throughs occur, which are to be prevented.

[0061] This embodiment of the bushings 8 from Fig. 3 is shown again three-dimensionally in Fig. 4. Here, the structure of such a bushing can be seen. Firstly, the starting body or base body of the bushing 8 preferably has a polygonal cross-section. In the example in Fig. 4, this can be viewed as an octagon or rather as a square with bevelled corners. Such a bushing 8 also has a central through-bore for pulling the bushing 8 onto the agitator shaft 3. The bushing 8 then has two end faces 10. Starting from this respective end face 10 towards the center of the bushing 8, the initial basic shape is initially retained for a few millimeters, whereby an end face section 11 is formed. From the respective end face section 11 towards the center, a transition region 13 is formed, which is spherical in this case.This transition area 13 then merges into the waist 9 in the central area of ​​the bushing 8, which has at least partially a circular cross-section.

[0062] The circumference of the respective cross sections decreases continuously from the front side section 11 to the waist 9.

[0063] This second embodiment of the bushing 8 from Fig. 4 also has a connecting web 16 on each of the four sides, which connect the end faces 10 to each other and bridge the waist 9.

[0064] The resulting pulse generators 7 are shown hatched in Fig. 4 for clarity. As mentioned, these pulse generators 7 are primarily responsible for the radially outward-acting pulse on the grinding media, while the grinding media are guided from the waist 9 via the transition region 13 preferentially to these pulse generators 7 and / or the grinding discs 4.

[0065] Thus, it is generally preferred that the locally caused movement vector of a grinding body after collision with the pulse generators 7 has a movement component in the radially outward direction which accounts for at least 60%, preferably at least 75%, of the total movement vector.

[0066] And after a collision with the waist 9, the movement vector of a grinding body caused in each case has a movement component in the axial direction which accounts for at least 60%, preferably at least 75%, of the total movement vector.

[0067] The fact that the waist 9 preferably does not have to be bridged by connecting webs 16 at all is shown by a further embodiment of the bushing 8, which is depicted in Fig. 5a and Fig. 5b. Here, too, the bushing 8 has a polygonal base body, which in this case represents a hexagon. This basic shape is also retained for a few millimeters from the respective end face 10 until it transitions into the waist 9 via the transition area 13. The waist 9 has a circular cross-section. The pulse generators 7 of the bushing 8 are again shown hatched. Fig. 5a also shows the bushing axis 15, which, when manufactured and assembled as intended, preferably essentially coincides with the axis of rotation of the agitator shaft 3.

[0068] To facilitate the assembly of the bushing 8 onto the agitator shaft 3 and to provide anti-rotation protection against the agitator shaft, the bushing 8 preferably also has a plurality of grooves 17 in the base of the central through-bore, extending over the entire length of the bushing 8. For this purpose, the agitator shaft 3 must, of course, have complementary thickened portions that can engage in these grooves 17.

[0069] Another almost identical embodiment of the bushing 8 is shown in Figs. 6a to 6c. However, compared to the previous embodiment, this has a starting body with a purely square initial shape.

[0070] That the pulse generators 7 can be formed not only by continuing the original shape becomes clear from another embodiment of the bushing 8, which is shown in Figs. 7a to 7c. Here, the pulse generators 7 (again hatched) represent flattened areas that are parallel to the bushing axis 15. The original starting shape of the bushing 8 represents a square bushing that was turned down by a curved waist 9.

[0071] The waist 9 itself can also be only a few millimeters wide or even represent only the connection between the transition areas 13, which touch in the center of the bushing 8. An embodiment configured in this way is shown in Figs. 8a to 8c.

[0072] 1 agitator mill

[0073] 2 grinding containers

[0074] 3 agitator shaft

[0075] 4 grinding disc

[0076] 5 not awarded

[0077] 6 horizontal axis or agitator shaft axis

[0078] 7 pulse generators

[0079] 8 socket

[0080] 9 Waist

[0081] 10 Front side of the socket

[0082] 11 Front section of the socket

[0083] 12 baffles

[0084] 13 Transition or transition area

[0085] 14 Grinding chamber

[0086] 15 Bushing axis

[0087] 16 connecting bridge

[0088] 17 grooves

[0089] 101 Entrance

[0090] 102 Outlet

[0091] 103 Sieve

[0092] 104 Basket D B Inner diameter of grinding container D W Diameter of agitator shaft

Claims

PROTECTION CLAIMS 1. Agitator mill (1), in particular in the form of a full-space disc mill, with a grinding container (2), an agitator shaft (3) rotating therein about a horizontal axis (6), which carries a plurality of grinding discs (4) connected to it in a rotationally fixed manner and spaced from one another in the direction of the horizontal axis (6), wherein the grinding discs (4) each have slots or openings, characterized in that the agitator mill (1) has drivers in the region between two grinding discs (4) which rotate synchronously with the grinding discs (4) during grinding and which impart a movement component in a radially outward direction to at least some of the grinding bodies coming into contact with them by directly displacing these grinding bodies during their rotation, preferably in a radial direction.

2. Agitator mill (1) according to claim 1, characterized in that a driver has at least one section with a non-circular surface profile - with respect to the horizontal axis (6) of the agitator shaft (3), which forms a pulse generator (7) by which the grinding bodies are displaced during rotation of the driver.

3. Agitator mill (1) according to claim 1 or 2, characterized in that the driver bushes (8) are formed which overlap the agitator shaft (3) in the free area between the grinding discs (4), or are formed integrally by the agitator shaft (3) in this area or are an integral component projecting from the end face of at least one grinding disc (4), wherein between two immediately adjacent grinding discs (4) preferably in each case one single bushing (8). Agitator mill (1) according to one of the preceding claims, characterized in that bushings (8) each have the initial shape of a body with a polygonal cross-section, which between its end faces (10) has at least in sections a waist (9) whose cross-section has a smaller circumference than the polygonal cross-section of the initial shape. Agitator mill (1) according to claim 4, characterized in that the cross-section of the waist (9) at least predominantly represents a circle, preferably with a constant diameter over the length of the waist (9). Agitator mill (1) according to one of the preceding claims, characterized in that the transitions (13) between the respective end faces (10) and / or end face sections (11) and the waist (9) are bevelled, preferably conical or spherical.Agitator mill (1) according to one of the preceding claims, characterized in that the waist (9) of the bushings (8) is bordered by a surface opposite the pulse generators (7) which is curved in such a way that it does not form a pulse generator (7) even when the bushing (8) rotates. Agitator mill (1) according to one of the preceding claims, characterized in that the bushings (8) have inclined surfaces in the region of their waist (9), preferably in the transition region (13) between the waist (9) and the end face (10) and / or between the waist (9) and the end face section (11), which are designed in such a way that the grinding bodies are guided by them into an inclined position precisely by the rotation of the bushings (8). A movement running in the circumferential direction of the agitator shaft (3) is forced upon it and in the process is preferably also pushed into the region of the middle between two immediately adjacent grinding discs (4). Agitator mill (1) according to one of the preceding claims, characterized in that the bushings (8) are tapered such that the length of their waist (9) is at least 45% of the distance between two immediately adjacent grinding discs (4), in each case measured in a direction parallel to the horizontal axis (6) of the agitator shaft (3). Agitator mill (1) according to one of the preceding claims, characterized in that at least 45% of the bushing surface facing the grinding chamber (14) is free of pulse generators (7). Agitator mill (1) according to one of the preceding claims, characterized in that the waist of the bushings (8) is free of pulse generators (7).Agitator mill (1) according to one of the preceding claims, characterized in that the pulse generators (7) are arranged predominantly or even entirely in the vicinity of the grinding disc end faces; preferably, said vicinity is less than or equal to 1 / 4 of the distance between two immediately adjacent grinding discs (4) - measured in the direction of the horizontal axis (6) of the agitator shaft (3). Agitator mill (1) according to one of the preceding claims, characterized in that the grinding discs (4) have at least one, preferably several, openings through which the grinding bodies are guided from an intermediate space between. two grinding discs (4) can reach the adjacent space between two grinding discs (4).

14. Agitator mill (1) according to one of the preceding claims, characterized in that flow breakers (12) are arranged between the grinding discs (4), which project from the inner surface of the grinding container into the free area between two grinding discs (4), preferably directly above the waist of the bushings (8), ideally in the area of ​​their center.

15. Agitator mill (1) according to one of the preceding claims, characterized in that the flow breakers (12) are preferably arranged asymmetrically in the circumferential direction, ie in the space between two immediately adjacent grinding discs (4) they are located closer to one grinding disc (4) than to the other grinding disc (4).

16. Driver, preferably in the form of a bushing (8), which is arranged in the area between two adjacent grinding discs (4), characterized in that this driver rotates synchronously with the grinding discs (4) during grinding and imparts a movement component in a radially outward direction to at least some of the grinding bodies coming into contact with them by directly displacing these grinding bodies during their rotation, preferably in the radial direction.

17. Driver, preferably in the form of a bushing (8), according to the immediately preceding claim, characterized in that the driver is designed according to at least one feature of claims 2 to 15 relating to the driver and / or the bushing (8).

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