WO2016082812A1 - Method for regulating the delivery capacity of a rotor of a separating device of a stirred ball mill, and stirred ball mill for comminuting material to be ground - Google Patents

Abstract

The invention relates to a method for regulating the output of a rotor of a separating device of a stirred ball mill for comminuting material to be ground with the aid of grinding balls. The stirred ball mill has a preferably cylindrical, horizontally arranged grinding vessel, at least one stirring unit which is driven by means of a drive, a material inlet, and a fine material outlet. At least the fine material outlet is assigned a separating device with a rotor for retaining the grinding balls. The material to be ground is pumped by means of an external pump via the material inlet into the stirred ball mill. According to the invention, the internal volume of the grinding chamber near the separating device and/or the flow cross section near the separating device can be adjusted on the basis of the throughput of material to be ground through the stirred ball mill, that is to say, in particular, according to a pumping speed of the external pump. The invention further relates to a stirred ball mill.

Description

 METHOD FOR REGULATING THE CONVEYING PERFORMANCE OF A ROTOR OF A DISCONNECTING DEVICE OF AN EMPTYING BALL MILL AND EMBODIMENT BALL MILLING FOR DISINTERIZATION OF MEAL

The present invention relates to a method for regulating the

Delivery rate of a rotor of a separating device of a stirred ball mill and a stirred ball mill for comminuting ground material according to the features of the preambles of claims 1 and 10.

State of the art

The present invention relates to a stirred ball mill with separating or classifying device. Such agitator ball mills are known for example from the prior art and are used for coarse, fine and fine crushing or homogenization of ground material. They consist of a grinding chamber in which regrind is comminuted by grinding media. In general, the grinding chamber by a horizontally mounted approximately circular cylindrical

Grinder container built. The mills are usually filled through an opening in one of the end walls. The discharge depends on the design and takes place, for example, through slots in the grinding space wall at the end of the mill, the grinding bodies being retained by a separating device. This separator is also referred to as a classifier. Classification is understood to mean the separation of a dispersed solid mixture into fractions, preferably according to the criteria

Particle size or particle density. In the present case, this relates to the separation into grinding media and sufficiently finely ground product or regrind. Since in this case the geometric particle size is the separation criterion, the classification is carried out, for example, by means of sieves or sieve-like separating devices. The result is at least two fractions, which differ in that the minimum limit of one fraction is at the same time the upper limit of the other fraction.

Agitator ball mills are usually made of a vertically or horizontally arranged, usually approximately cylindrical grinding container, which is filled to 70 - 90% with grinding media. The grinding container is in agitator ball mills in usually stationary, not rotating. An agitator with suitable

Stirring elements ensures the intensive movement of the grinding media together with the material to be ground. The grinding media consist for example of steel or wear-resistant ceramic materials. The millbase, for example a millbase suspension, is pumped continuously through the grinding chamber. This will be the suspended

Solids crushed or dispersed by impact and shear forces between the grinding media. At the discharge of the mill, the separation of regrind and grinding media by means of a suitable separator.

The object of the invention is to provide methods and a stirred ball mill in which the wear of the separating device or classifying device can be reduced by contact with the grinding bodies and / or which can be set optimally for the respective product and / or the respectively desired throughput quantity.

The above object is achieved by a method and agitator ball mill having the features in independent claims 1 and 10. Further advantageous embodiments are characterized by the subclaims

described.

The invention relates to a method for regulating and / or optimizing the

Delivery rate of a rotor of a separator of a stirred ball mill. Such a stirred ball mill is used for the comminution of ground material by means of grinding media in a preferably cylindrically shaped, horizontally arranged grinding container. The grinding container is assigned at least one drive for driving an agitator within the grinding container. The at least one

Drive shaft of the agitator is preferably mounted outside the grinding chamber and sealed by a mechanical seal in an end wall of the horizontal grinding container against this. In stirred ball mills with two driven agitators, the two drive shafts of the two drives, which are preferably independent of one another, are mounted, for example, in the opposite end walls of the horizontal grinding container. The agitator ball mill comprises a material inlet and a

Fine-material outlet for ready-milled product. About the fines outlet is carried out during operation of the agitator ball mill finished comminuted millbase, while the grinding media by means of a separator or

Classifier be retained in the grinding chamber. The agitator ball mill can furthermore have a coarse material outlet. The coarse material outlet is preferably closed during operation of the stirred ball mill. He can for

Emptying the grinding chamber can be opened so that the interior of the grinding container can be cleaned, for example, in the context of a product change. The regrind is by means of an external pump via the material inlet in the

Agitator ball mill pumped.

According to one embodiment of the invention, the material inlet in agitator ball mills with a driven agitator is preferably designed as a central opening in the second end wall, which lies opposite the first end wall with the bearing of the drive shaft. The fine material outlet is often formed in the region of the bearing of the drive shaft on the first end wall. the

Fines outlet is assigned a separator or classifier with rotor for separating and retaining the grinding media in the grinding chamber. The coarse material outlet is preferably arranged in a region of the cylindrical jacket surface of the grinding stock container.

According to one embodiment of the invention, the material inlet in agitator ball mills with two driven agitators is preferably arranged in a central, upper region of the cylindrical jacket surface of the grinding stock container. The fine material outlet is generally formed in the region of the bearing of a drive shaft and the coarse material outlet is formed in the region of the bearing of the other drive shaft mounted in the opposite end wall. The respective material outlet for fines and coarse material in each case has a separate separating device, each with a separate drive. The separator or classifier serves to retain the grinding media in the grinding chamber during the discharge of ground product from the grinding chamber. At this

Embodiment of a stirred ball mill with two driven agitators can when using drive shafts with different geometry and Speed be used the opportunity to separate by means of agitator ball mill two fractions, in particular a finer and a coarser product, the grinding media usually remain in the grinding chamber.

The invention aims, in particular, at the internal circulation of the product and grinding aid bodies, in particular in the area of the rotor of the grinding chamber

 Separator, adjust and adjust. According to the invention, the internal volume of the grinding chamber in the region of the separating device and / or the flow cross section within the grinding chamber in the region of the separating device is determined by the throughput of ground material by the agitator ball mill and / or by other physical parameters of ground material and / or

 Agitator ball mill set. In particular, the setting is made in

Dependence on the pumping speed of the external pump for the regrind.

The adjustment preferably takes place by means of an adjusting device arranged inside the grinding container, which comprises at least one volume-variable and / or position-variable element.

According to a preferred embodiment, the adjusting device comprises an elastic element whose volume is adjustable. In particular, the volume of space occupied by the elastic element can be adjusted by filling with a fluid and / or by emptying. According to one

According to an embodiment of the invention, the elastic element has an internal cavity which can be filled with a suitable fluid in order to change the volume of space occupied by the elastic element. When filling the inner cavity with fluid, the elastic element expands and thus has an increased volume. The elastic element thus occupies more space within the grinding chamber, whereby the internal volume of the grinding chamber for the

Grist is reduced. If, however, fluid is removed from the inner cavity of the elastic element, the elastic element decreases accordingly. For adjusting the size of the elastic element, preferably incompressible media are used, for example water or suitable oils. By changing the of the elastic element

occupied volume of the interior volume of the grinding chamber changes in Area of the separator and / or it changes the flow cross-section within the grinding chamber in the region of the separator

According to an alternative embodiment, the adjusting device comprises a position-variable element which is displaceably mounted relative to the separating device 5. The distance between the position variable element and the

 Separator can be adjusted, by approximating the

 position variable element to the separator the internal volume of the

 Mahlraums in the region of the separating device and / or the flow cross section within the grinding chamber in the region of the separating device is reduced. In accordance with one embodiment of the invention, the adjustment of the

 Internal volume of the grinding chamber and / or the adjustment of the flow cross-section within the grinding chamber in the region of the separator due to a

 Pressure difference between the fines outlet and the material inlet of the

 Stirred ball mill. For example, it may be provided that on the

5 fine material outlet and the material inlet in each case a pressure sensor is mounted and that the agitator ball mill comprises a control unit. The pressure sensors are coupled to the control unit. The pressure sensors determine the pressure at the respective measuring point and transmit these values to the control unit. This calculates the current pressure difference between the fine material outlet and the material inlet of the agitator ball mill, compares the determined value with a previously known setpoint value and, on the basis of the determined difference between the actual value and the setpoint value, controls the setting device and thus the correct one

 Adjusting the internal volume of the grinding chamber in the region of the separating device and / or the correct setting of the flow cross section within the grinding chamber in the region of the separating device.

According to an alternative embodiment, the adjustment of the adjusting device takes place due to the power consumption of the agitator ball mill. In particular, the change in the power consumption of the agitator ball mill is measured when the flow rate is changed, and then the adjustment of the o adjustment device is regulated and controlled. From the value of the power consumption of the agitator ball mill can be in particular concluded whether the grinding media are in the separation area or not. For example, at a Increasing the flow rate measured an increase in power consumption, the internal volume of the grinding chamber in the region of the separator and / or the flow cross-section within the grinding chamber in the region of the separator is increased, for example by fluid is removed from the inner cavity of the elastic member or by the distance between the position variable element and the separator is increased.

According to a further embodiment of the invention, the rotor of the separator produces a directed away from the drive shaft of the agitator

Product stream. This product stream is divided outside the rotor in a first directed to a drive-side end wall of the grinding container partial flow, the so-called short-circuit current, and a second, at least one

Stirrer of the agitator directed partial flow, the so-called reflux flow, on. By means of the adjustment, the quantitative distribution of

Product flow in the first partial flow or second partial flow can be adjusted specifically and adapted to the pumping speed of the external pump. That is, depending on the generated by the external pump

Material flow can be adjusted, whether that generated by the rotor

Product flow is directed to a greater or lesser extent in the direction of the stirring disc or in the direction of the drive-side end wall. The core of the invention is therefore an adjusting device for adjusting the internal circulation of an agitating ball mill. The adjusting device is preferably arranged on a non-rotating component in the region of the separating device at the material outlet of the stirred ball mill.

The functional component of the adjusting device is a variable element in the region of the respective separating device, which via the differential pressure between the

Fine material outlet and the material inlet of the agitator ball mill or the

Power consumption of the agitator ball mill is regulated. The change in the variable element leads to changes in the distance between rotating and stationary parts of the agitator ball mill and thus leads to changes in flow cross sections and / or the mill internal product flows. In order to be able to adapt the adjusting device to the throughput in the agitating ball mill, pressure is applied to it in one embodiment or pressure is reduced. The greatest internal product throughput is possible when the pressure on the device is near zero and the device is at its maximum

Flow cross section within the grinding chamber releases. In an embodiment with an elastic element which rests almost completely against the container wall, at a lower throughput in the agitator ball mill, the

Adjustment device from the rear, so from the container side, pressurized. This increases the elastic element and thus reduces the cross section of the agitator ball mill in the region of the separating device, in particular the space or distance between the grinding container and the separating device is reduced.

With the aid of the adjustment device and with the aid of the described method, the delivery rate and flows around the separation device, in particular in the outlet region of the agitator ball mill, can be adjusted and adjusted. Thus, the residence time spectrum of the product in the grinding chamber can be varied without changing the pump throughput. Thus, the wear of the separator can be reduced. In particular, thus a size of a

Agitator ball mill can be used optimally for different throughput quantities.

figure description

In the following, embodiments of the invention and their advantages with reference to the accompanying figures will be explained in more detail. The proportions of the individual elements to one another in the figures do not always correspond to the actual size ratios, since some shapes are simplified and other shapes are shown enlarged in relation to other elements for better illustration.

Figure 1 shows a cross section through a first embodiment of a ball mill with a driven agitator according to the prior art.

Figures 2 to 4 each show a cross section through different

Embodiments of a ball mill according to the invention. For identical or equivalent elements of the invention, identical reference numerals are used. Furthermore, for the sake of clarity, only reference symbols are shown in the individual figures, which are required for the description of the respective figure. The illustrated embodiments are only examples of how the device according to the invention can be designed and do not represent a final limitation.

Figure 1 shows a cross section through a first embodiment of a ball mill 1 with a rubbed by a drive 3 agitator 5 according to the prior art. In particular, this is a

Agitator ball mill 2 with a horizontally arranged cylindrical grinding container 7. Via a drive 3 and an associated drive shaft 4, the agitator 5, which comprises four stirrer discs 5 ^* in the illustrated embodiment, set in rotation and thus provides within the grinding chamber 8 for the intensive movement of the grinding media together with the regrind. The drive shaft 4 is over a

Sealed mechanical seal 6 and stored outside in a first end wall 15a of the horizontal grinding container 7.

In the opposite second end wall 15b, a central opening is formed as a material inlet 13, via which the material to be comminuted and / or the grinding media are introduced into the grinding chamber 8. The discharge of the ground product takes place in the example shown via a fine material outlet 11 in the first

End wall 15a. The grinding media are through a separator 10th

or classifier 10 ^* retained. The fine material flows radially through holes in a sieve of the separator 10. The sieve is attached to the end wall 15a that effluent product only through the sieve openings the

Grinding chamber 8 can leave.

Between a drive-side first stirring disc 5 * of the agitator 5 and the drive-side first end wall 15a, a rotor 50 is arranged. This comprises in particular a rotor disk 52 with openings 53 for the material to be comminuted and the grinding media. At the outer edge of the rotor disk 52 so-called rotor fingers 55 are arranged, which extend in the direction of the drive-side first end wall

15a extend. The rotor fingers 55 are arranged in particular uniformly spaced from one another. The rotor fingers 55 are at their drive end over a rotor ring 57 connected to each other. The rotor 50 thus forms a cage open on the drive side about the axis of the drive shaft 4.

The material to be comminuted is pumped by means of an external pump via the material inlet 13 in the flow direction FA in a volume flow VA in the grinding chamber 8 of the grinding container 7. In particular, it passes through openings 60 in the stirrer discs 5 ^* and the openings 53 of the rotor disk 52 in the space between the rotor cage and sieve of the separator 10. Upon rotation of the drive shaft 4, the rotor 50 acts as a pump and builds a directed outward into the grinding chamber 8 Product stream of material to be comminuted or at least partially comminuted in the flow direction FB. The rotor 50 sucks the product stream close to the drive shaft 4. The grinding media have a higher density than the material to be comminuted. For this reason, owing to the centrifugal forces within the agitator ball mill 2, there are no or only a small number of grinding bodies on the drive shaft 4. Thus, the product flow generated by the rotor 50 consists at least largely only of material to be comminuted or at least partially comminuted.

The product flow constructed by the rotor 50 in particular has a higher volume flow VB than the material flow via the material inlet 13. The product stream is divided outside the rotor cage into a partial flow Fe in the direction of the stirring disc 5 * and into a partial flow FD in the direction of the drive-side first end wall 15a , This partial flow FD flows around the rotor ring and the crushed material leaves the agitator ball mill 2 via the sieve of the

Separator 10 at the fine material outlet 1 1. The directed in the direction of the stirring disk 5 ^* partial flow Fe counteracts the external pump and thus the material flow in the flow direction FA. By the partial flow Fe are at the

Behälterinnenwandung the grinding container 7 located Mahlkörper entrained in the direction of the stirring disk 5 ^* .

In a rotor 50 having a constant geometry and a constant speed, the return flow rate of the product flow is defined. The throughput of the agitator ball mill 2 is by changing the

Pump speed of the external pump adjusted. It shifts within the agitator ball mill 2, the point at which the forces of the external pump (flow direction FA) and the return force in the flow direction Fe cancel each other out.

Furthermore, it is indicated in FIG. 1 that the inner lateral surface of the

Grist container 7 to protect against wear with wear protection elements 1 2 is equipped. The agitator ball mill 2 with only one drive 3 thus has a material inlet 13, an outlet for fines 11 and a classifier 10 *.

Figures 2 to 4 each show a cross section through different

Embodiments of a ball mill 20 according to the invention. These are in each case agitator ball mills 22 with a drive 3 analogous to FIG. 1. The components of the ball mills 20 known from the prior art are the same

Reference numerals as used in the description of Figure 1. For the description of these components, reference is hereby made to the description of FIG.

The setting device 30 is used to adjust the return capacity of the rotor 50. The adjustment device 30 is in the region of the separating device 10, 14 (see FIG. 1) at the material outlet 11 of the stirred ball mill 2 preferably arranged on a non-rotating component.

FIGS. 2 to 4 show by way of example the arrangement of FIG

Adjusting devices 30 in a stirred ball mill 22 with a drive 3. The adjusting device 30 comprises a variable element 32 in the region of the respective separating device 10. This is, for example, an elastic element 33 which is variable in volume. For example, the volume of space of the elastic element 33 can be increased by inflation or filling with a suitable fluid. By discharging fluid, the occupied by the elastic member 33 space volume is reduced again.

Alternatively, as a variable element 32, a so-called displacement body can be used, which can be displaced, whereby the internal volume of the grinding chamber 8 or the flow cross-section within the

Mahlraums 8 in the region of the separator 10 increases or decreases. Within the grinding container 7, there is a pressure difference between the fine material outlet 11 and the material inlet 13. The pressure at the fine material outlet 1 1 and the material inlet 13 is determined in each case via suitable sensors 40-13, 40-1 1. The measured data for the pressure are transmitted to a control unit (not shown). This calculates the differential pressure Δρ and then controls depending on the current flow VA a setting means 42, for adjusting the variable element 32. The change to the variable element 32, ie

either the change of the occupied by the elastic element

Volume volume or changing the position of the displacer lead to changes in the distance between rotating and stationary parts of the

 Agitator ball mill 22. This causes a change in the flow cross sections within the grinding chamber and thus a change in the internal mill

Product streams.

In order to be able to adapt the adjusting device 30 to the throughput in the agitating ball mill 22, in each case pressure is applied to these embodiments shown in FIGS. 2 to 4 by the adjusting means 42 or pressure is reduced so that the volume of the adjusting device 30 changes accordingly , The greatest internal product throughput is possible when the pressure on the adjuster 30 is nearly zero and the adjuster 30 releases the maximum flow area within the mill space.

With the adjusting device 30 according to Figure 2, the distance between the rotor ring 57 and the drive-side first end wall 15a of the grinding container 7 can be changed. If the gap between the rotor ring 57 and the drive-side first end wall 15a approaches zero, the so-called short-circuit current in the direction of flow FD is canceled out and the whole conveyed through the rotor 50

 Product flow has only the flow direction Fe in the direction of the stirring discs 5 *.

FIG. 3 shows an embodiment with an elastic element 33 which bears almost completely against the container wall of the grinding container 7. With the adjusting device 30 according to FIG. 3, the distance between the rotor disk 52 and the grinding container inner wall can be changed. Does the gap between the

Rotor disc 52 and Mahlbehälterinnenwandung to zero, so is the

Material flow in the direction Fe in the direction of the stirring disc 5 * repealed and the Entire product flow delivered by the rotor 50 has only the flow direction FD in the direction of the drive-side first end wall 15a. Thus, none occurs

Recovery of material in the direction of the grinding discs. This is the case in particular when the volume flow VA generated by the external pump corresponds to the speed of the product volume flow VB generated by the rotor 50 (see FIG. 1).

If the throughput in the agitator ball mill 22 is now lower, the adjusting device 30 is adjusted by the adjusting means 42 from the rear, ie from the

Container side, pressurized and thus reduces the cross section of the grinding chamber 8 in the region of the separator 10. In particular, the space between the grinding container 7 and the separator 10 is reduced. For example, it may be provided that the adjusting device 30 consists of individual segments and that it is provided to selectively apply the pressure in each case in individual segments, so as to achieve a very targeted adjustment of the flow cross-section in defined areas of the grinding chamber 8.

With the aid of the adjusting device 30, the return capacity of the rotor 30 of the separating device 10 in the outlet region of the agitator ball mill 22 can be adjusted. In particular, it can be adjusted whether more of the product flow pumped by the rotor 50 is pumped back in the direction of the stirring disk 5 ^* or in the direction of the drive-side first end wall 15a. This allows a particularly advantageous distribution of the grinding media in the grinding chamber 8. The grinding media in particular must be widely distributed around the stirring disk 5 ^* to a good

To achieve grinding of the product to be shredded. This can do that

Dwell time spectrum of the product in the grinding chamber 8 without changing the

Pump throughput can be varied. Furthermore, with the aid of the adjusting means 42 and the adjusting device 30, the discharge amount of fine and / or coarse material can be adjusted. Thus, a size of a stirred ball mill 22 can be optimally used for different throughputs of regrind.

By adjusting the residence time spectrum of the product in the grinding chamber 8, the contact time between regrind or grinding media and

Separator 10, 14 optimized, in particular minimized. shorter Contact times cause less wear and thus increase the

Life of the separators 10, 14th

The invention has been described with reference to a preferred embodiment. However, it will be apparent to those skilled in the art that modifications or changes may be made to the invention without departing from the scope of the following claims.

LIST OF REFERENCE NUMBERS

1 ball mill

 2 agitator ball mill

 3 drive

 4 drive shaft

 5 agitator

5 ^* stirring disc

 6 slide ring direction

 7 grinding containers

 8 grinding room

 10 separating device

 10 * classifier

 11 fine-material outlet

 12 wear protection

 13 material inlet

 14 separating device

 15 front wall

 20 ball mill

 22 agitator ball mill

 30 adjustment device

 32 variable element

 33 elastic element

40 pressure sensor 2 Adjusting means0 Rotor2 Rotor disk3 Opening5 Rotor finger7 Rotor ring0 Opening

F flow direction v volume flow

Claims

claims Method for regulating the delivery rate of a rotor (50) of a  Separating device (10) of a stirred ball mill (20, 22) for comminuting material to be ground with the aid of grinding media, the agitator ball mill (20, 22) a preferably cylindrical trained, horizontally arranged grinding container (7), at least one by means of a drive (3) driven agitator (5), a material inlet (13) and a fine material outlet (11), wherein at least the fine material outlet (11) is associated with a separating device (10, 14) with a rotor (50) for retaining the grinding media, wherein the material to be ground by means of an external Pump is pumped via the material inlet (13) in the agitator ball mill (20, 22), characterized in that the internal volume of the grinding chamber (8) in the region of at least one separating device (10, 14) and / or that a flow cross-section within the grinding chamber ( 8) in the region of the separating device (10, 14) of  Agitator ball mill (22) is adjusted in response to a pumping speed of the external pump. A method according to claim 1, wherein the adjustment of the internal volume of the grinding chamber (8) in the region of the at least one separating device (10, 14) and / or the adjustment of the flow cross section within the grinding chamber (8) in the region of the separating device (10, 14) by means of a Adjustment device (30) takes place, which comprises at least one volume-variable and / or position-variable element (32). 3. The method of claim 2, wherein the adjusting device (30) comprises an elastic element (33) whose volume is adjustable. 4. The method of claim 2, wherein the volume of space by filling an inner cavity of the elastic member (33) with a fluid and / or by emptying the inner cavity of the elastic member (33) is adjustable, wherein by filling of the fluid by the elastic Elementes (33) increases occupied volume and thus the internal volume of the grinding chamber (8) in the region of the separating device (10, 14) and / or the flow cross-section within the grinding chamber (8) in the region of the separating device (10, 14) is reduced. 5. The method of claim 2, wherein the adjusting device (30) a  variable position member, which is slidably mounted relative to the separating device, and wherein the distance between the  position variable element and the separating device (10, 14) is adjustable, wherein by approaching the position variable element to the  Separating device (10, 14), the internal volume of the grinding chamber (8) in the region of the separating device (10, 14) and / or the flow cross-section within the grinding chamber (8) in the region of the separating device (10, 14) is reduced. 6. The method according to any one of the preceding claims, wherein the adjustment of the internal volume of the grinding chamber (8) in the region of the separating device (10, 14) and / or the adjustment of the flow cross-section within the grinding chamber (8) in the region of the separating device (10, 14) due to a pressure difference (Δρ) between the fine material outlet (1 1) and the  Material inlet (13) of the agitator ball mill (20, 22) takes place. 7. The method of claim 6, wherein the pressure difference (Δρ) is determined by sensors and wherein the adjustment of the internal volume of the grinding chamber (8) in the region of the separating device (10, 14) and / or the setting of the  Flow cross section within the grinding chamber (8) in the region of Separating device (10, 14) is controlled by a control unit. Method according to one of claims 1 to 4, wherein the adjustment of the internal volume of the grinding chamber (8) in the region of the separating device (10, 14) and / or the adjustment of the flow cross section within the Mahlraums (8) in the region of the separating device (10, 14) is calculated on the basis of the change in power consumption of the agitator ball mill (20, 22) when changing the flow rate. Method according to one of claims 2 to 8, wherein the rotor (50) of the separating device (10, 14) generates a product flow (FB) directed away from a drive shaft (4) of the agitator (5), wherein the product flow (FB) in a first partial flow (FD) directed to a drive-side end wall (15a) of the grinding container (7) and a second partial flow (Fe) directed to at least one stirring disc (5 *) of the agitator, wherein the quantitative distribution of the partial flow is determined by means of the adjusting device (30) Product flow (FB) in the first partial flow (FD) and second partial flow (Fe) specifically adjusted and adapted to the pumping speed of the external pump. Agitator ball mill (20, 22) for comminuting ground material with the aid of grinding bodies, with a preferably cylindrically shaped, horizontally arranged grinding container (7), with at least one by means of a drive (3) driven agitator (5), wherein the at least one drive shaft (4 ) of the agitator (5) is movably mounted in an end wall (15) of the grinding container (7), the agitator ball mill (20, 22) having a material inlet (13) and a fine material outlet (11), at least the Fine material outlet (11) is associated with a separator (10, 14) with a rotor (50) for retaining the grinding media, wherein the agitator ball mill (20, 22) an external pump for pumping in ground material over the Material inlet (13), characterized in that the Agitator ball mill (20, 22) comprises an adjusting device (30), by means of which the internal volume of the grinding chamber (8) and / or a Flow cross section within the grinding chamber (8) in the region of Separating device (10, 14) is adjustable. Agitator ball mill (20, 22) according to claim 10, wherein the Adjusting device in the region of a separating device (10, 14) on a material outlet (9 ^* , 11) on a non-rotating component of Agitator ball mill (20, 22) is arranged. Agitator ball mill (20, 22) according to claim 10 or 11, wherein the Adjustment device (30) comprises at least one volume-variable and / or position-variable element (32). Agitator ball mill (20, 22) according to claim 12, wherein the Adjustment device (30) comprises an elastic element (33) with an inner cavity, wherein the volume of the elastic element (33) is adjustable by filling the inner cavity with a fluid and / or by at least partially emptying the cavity at least partially filled with a fluid , Agitator ball mill (20, 22) according to claim 10 or 11, wherein the An adjusting device (30) a position variable element (32) which is arranged displaceably relative to the separating device, and wherein the distance between the position variable element (32) and the separating device (10, 14) is adjustable. Agitator ball mill (20, 22) according to any one of claims 10 to 14, wherein the fine material outlet (11) and the material inlet () each having a pressure sensor (40) is associated and wherein the agitator ball mill comprises a control unit.