EP2676725B1 - Method and device for mixing, in particular for dispersion - Google Patents

Description

The present invention relates to an apparatus and a method for mixing, in particular dispersing.

In practice, for example in the paint industry, a predetermined amount of liquid is often premixed with a predetermined amount of a powdery solid, usually pigment. Such mixtures are then further ground and dispersed in stirred mills, if necessary. Exemplary industrial applications are the production of paint and varnish or the like.

In the present case, mixing is understood as meaning the combination of substances or streams in such a way that the composition is as uniform as possible. In the context of the invention, the mixing is used in particular for the preparation of dispersions, ie dispersing. In this case, a dispersion is understood as meaning a heterogeneous mixture of at least two substances which do not dissolve or hardly dissolve into one another or chemically combine with one another. In the process of dispersing, a substance (disperse phase) is dispersed as finely as possible in another substance (dispersion medium or continuous phase), if appropriate using grinding aid bodies; In stirred mills, for example, spherical grinding aids are frequently used. The present invention relates in particular to (the preparation of) suspensions - ie dispersions in which a liquid forms the continuous phase and a solid forms the disperse phase. In addition to the uniform distribution of the disperse phase in the continuous phase, the dispersion also means the wetting of the material to be dispersed with the dispersing agent and the comminution of the substance to be dispersed (and, if appropriate, the subsequent stabilization). Comminution may typically be the dissolution of agglomerates into primary particles. However, aggregates or associates (if an assembly by van der Waals forces or stronger chemical bonding types is effected) can, however, be comminuted when dispersed in primary particles. While the dissolution of agglomerates can also be achieved in devices without grinding auxiliary bodies, such as in a disperser or dissolver, devices for comminuting aggregates or crystals are used needed with Mahlhilfskörpern, such as a stirred mill with spherical Mahlhilfskörpern. By aggregates in the broader sense, larger crystalline or amorphous structures can be understood here. In the case of comminution of aggregates, crystalline or amorphous structures is spoken of real comminution.

Generic devices for mixing two substances, in particular a liquid and a solid such as a powder, usually have a housing and a rotor rotating therein. By means of at least one supply line, the substances are introduced into the housing. During operation of the device, the substances are mixed by means of the rotor and then discharged from the housing.

An apparatus for dispersing and an associated method are in US 6,029,853 described. The dispersing apparatus comprises a dispersing chamber, at least one stirring disk, an inlet through which the liquid with the material to be treated and the dispersion medium are sucked by the rotation of the stirring disk, an outlet, and a separator. The separating device is arranged at the outlet. By means of the separator, the Mahlhilfskörper be separated from the dispersion. In addition, the separator may discharge the dispersion through the outlet, retaining the grinding aids as described.

A device for homogenizing and / or dispersing a flowable material is in DE 200 09 105 U1 shown. The device comprises a stator and a rotor driven in rotation about an axis, the stator and the rotor having shearing and / or conveying elements. Furthermore, the device has a shear area, where the shear and / or conveying elements run past each other during the rotation of the motor. In addition, the device has at least one supply line. The supply line opens directly into the shear area.

It is disadvantageous that an effective comminution of agglomerates in the known devices takes place only to a small or insufficient extent.

From the documents DE 29613245 U1 and US 3311310 A Mills are known which have two process areas for regrind. In the first area, a dispersion is performed by a rotor. In the second area there is a discharge rotor.

From the documents CH 355770 in that a device according to the preamble of claim 1 is disclosed, and GB 722820 Grinding devices are known which achieve a comminution and mixing by means of shearing and / or fragmentation of particles. For this purpose, the devices have teeth.

Out WO 2007/104297 A2 a device for ore processing is known with which the mineral product first dry pre-crushed and then wetted with liquid and pre-ground. At the end of this comminution process, it is proposed to pass the product through an annular gap whose gap width is between 50 nm and 3 mm; this annular gap serves as a comminution device, in which the suspension reaches a greater fineness. The use of Mahlhilfskörpern such as. Spheres is not taught. In a downstream, separate processing stage ("final stage") then the desired final fineness can be achieved. In addition, the known devices are not optimized with regard to discharging the prepared mixture from the device. Likewise, depending on the substances to be processed for sucking in these substances, it is necessary to use auxiliary means such as upstream pumps or the like to assist them.

It is therefore the object of the present invention to avoid the aforementioned disadvantages of the prior art; In particular, an apparatus and a method for mixing are to be provided, whereby an effective mixing, in particular dispersion, as well as an improved discharge while still possible compact construction is possible.

The above object is achieved by a device and a method according to the independent claims. Further advantageous embodiments will become apparent from the dependent claims, the following description and the figures.

The device according to the invention comprises: a housing which has at least one, preferably two inlets and at least one outlet, a separating device which is arranged in the housing and with which the housing can be subdivided into a first process area and a second process area, and a rotor unit which is rotatably disposed in the housing, wherein the first process area comprises a first portion of the rotor unit, so that during operation of the device mixing of supplied by the at least one inlet materials by means of the first portion of the rotor unit in the first process area is feasible, and the second process area is disposed downstream of the first process area after the separation device and includes a second portion of the rotor unit, wherein the second portion of the rotor unit comprises an ejection means. The separator comprises static and / or dynamic gaps. The rotor assembly includes a rotor disk which extends through elements of the separator and forms a dynamic gap therewith. The second process area and the second section are designed in such a way that dispersion can be achieved and in the first process area grinding bodies, in particular spherical grinding bodies, are arranged.

The device according to the invention can be used, for example, for the production of paints, in particular car paints, printing inks, emulsion paints, emulsions, ceramic dispersions or the like. Furthermore, the device according to the invention can be used as a premixing or predispersing unit, wherein the mixture produced by means of the device according to the invention can subsequently be fed to an agitating mill in order to achieve an even greater fineness of the dispersion. By using the device according to the invention as a premixing or predispersing unit, smaller grinding auxiliary bodies (typically spherical) can be used in a downstream agitator mill compared to the prior art, which leads to a more effective operation of the downstream stirred mill.

At least two substances can be fed to the device via the at least one inlet. For example, this is a solid, such as a powder, as well as a liquid. Alternatively, each substance may be supplied to the device via a separate inlet, with each material being supplied to the first process area. If only one inlet is present, the device is charged with a prescriptive premix of the substances to be mixed. Preferably, two inlets are present; This makes it possible to charge the device with separate streams of dispersant and disperse phase.

Preferably, the device according to the invention is used for processing or producing mixtures with low to medium viscosity. The dynamic viscosity of the mixtures is between about 0.1 and about 20,000 mPas, measured at the appropriate operating conditions of the device according to the invention for the respective product to be produced. Suitable operating conditions may be between -10 ° C and 110 ° C, preferably between room temperature and 60 ° C.

During operation of the device, at least one substance, preferably one or more solids, is sucked in automatically on account of the rotor unit rotating inside the housing. The use of forced conveyors for solids is therefore not necessary. Compared to the known devices, in the device according to the invention, due to the ejection means arranged on the second section of the rotor unit, an advantageous suction effect, which in particular also controls the peripheral speed of the rotor unit, is achieved, which improves the discharge of the mixture from the device, which will be explained in detail later. In addition, a liquid can also be sucked in automatically by means of the device according to the invention.

As described above, during operation of the device, the at least two substances pass through the at least one inlet into the first process area of the device. In the first process area, the at least two substances are mixed by means of the first section of the rotating rotor unit. This first section of the rotor unit preferably comprises a stirring disk known per se, which is designed in this way is that it can entrain particles not only due to adhesion, but in particular also due to positive effects (for example, in the stirring disc penetrating channels).

Centrifugal forces generated by the rotation of the first section of the rotor unit flow the mixture of substances as well as the subsequent material flows from the first process area in the direction of the separation device; This is further supported by a negative pressure generated in the second process area by the ejection means, as will be explained below.

The separator may have static gaps, dynamic gaps, and combinations thereof. Static columns are understood to mean those which are not formed by at least partial limitation by the rotor. By contrast, dynamic gaps are understood to mean those which are formed between the rotor and static elements of the device. It is understood that a separator may have both static and dynamic gaps. A respective gap width of the static and dynamic column does not have to be identical in this case.

Elements of a static separator may be fixedly connected to the housing or to the rotor unit in the first section. Suitable elements of the separating device can extend perpendicularly from the respective surface of the housing into the interior and thus have two opposite axial ends.

The separator also has the task of a separation point for coarse contaminants, which may be contained in the solid, for example. These may be coarse particulate contaminants. By means of the separation device, at least such impurities are retained.

The gap width of the separator should not be greater than the distance of the ejector from the housing, starting from the smallest distance. In this way, damage to the ejection means can be effectively prevented. Furthermore, various embodiments can be implemented to carry out this task, some of which will be explained by way of example in the further course.

When elements of the separator are attached to the housing with a first end, a gap is formed between the second end of the separator opposite the first end of this element of the separator and the first portion of the rotor unit (eg, the stirring disk). The first section of the rotor unit preferably extends at least partially into the separating device in this case. The gap thus formed is referred to as a dynamic gap, as explained above. Thus, at least one planned gap or gap is formed in the radial direction between the separating device and the first section of the rotor unit. Furthermore, the first section of the rotor unit can have a bead, so that a gap is likewise formed in the axial direction between the first section of the rotor unit and the separating device.

Alternatively, elements of the separator may be attached to the first portion of the rotor assembly. In this case, the dynamic gap is formed between the element of the separating device rotating during operation of the device and the housing.

In a preferred embodiment, the separation device itself has gaps. These are referred to below as the static column. The gap width of the static column corresponds to the gap width of the dynamic gap or gap. The gap width of the separating device can be designed such that particles with a diameter of less than 4 mm, less than 3 mm, or less than 2 mm, or less than 0.25 mm can pass through the separating device when used as intended. Advantageously, coarser particles, in particular foreign bodies, are thus retained, which prevents destruction of the device according to the invention. This is due to the fact that no particles with a diameter greater than the distance between the ejector and the housing can pass through the separator.

After the mixture has passed the separator, it enters the second process area. In the second process area is the second section of the rotor unit, which has the ejection means. By the rotation of the ejection means, a pressure difference is generated, which has been found in the context of the invention to be advantageous.

Furthermore, the ejection means supports a discharge of the mixture formed in the first process area through the outlet. The ejection means preferably comprises a plurality of blades, paddles or the like for this purpose. The ejection means extend in the housing such that only a small distance is formed between the housing and the ejection means. The lower limit of a reasonable distance between ejector and housing (or other static parts) is due to the manufacturing tolerance of the device on the one hand and, on the other hand, by the urgent need for the ejector to move freely past static parts; Under these conditions, the distance can be chosen as small as possible. The distance is typically between 20 mm and 0.25 mm, or between 15 mm and 0.25 mm, or between 5 mm and 0.25 mm. It was found that such selected distances between the ejection means and the housing caused an additional dispersing effect between the ejection means and the housing. This further improves the quality of the produced mixture.

After leaving the device through the outlet, the mixture can either be re-supplied to the inventive device or it can be supplied for further processing, for example, a stirred mill.

An advantage of the inventive device is due to the separation device, as discussed above, the integrated filter function against foreign substances and the advantageous in the context of the invention suction effect. By mixing the substances in the device according to the invention, it is likewise possible to produce a premix, which is easier to process in subsequent work steps than in the prior art; For example, smaller balls can be used in downstream agitator mills. Depending on the application, however, it may also be possible to completely dispense with downstream devices.

According to the invention, the rotor unit comprises a rotor disk which extends through elements of the separator and forms a dynamic gap with them. The second portion of the rotor unit is thus located radially farther from the Rotor axis as the first portion of the rotor unit. This construction is relatively flat and easy to implement. Thus, this construction is also inexpensive.

Alternatively, the first portion and the second portion of the rotor unit are arranged adjacent to the rotor axis. In particular, the first and the second section of the rotor unit can thus be arranged one above the other with respect to a drive shaft of the rotor unit. In this embodiment, the separator may be disposed adjacent to the drive shaft at the first portion of the rotor assembly, which reduces the load on the separator during operation of the apparatus as compared to the embodiment described above. This will also be explained in detail later with reference to the drawings.

In a further preferred embodiment spherical Mahlhilfskörper are arranged in the first process area. In the present context, the term auxiliary grinding body in the context of the present invention comprises any freely movable, physically acting on the solid agent, in particular causing a mixing, (intensive) dispersion and / or a real comminution of aggregates, crystalline and amorphous structures. The Mahlhilfskörper arranged in the first process area are referred to as a Mahlhilfskörperfüllung. The Mahlhilfskörperfüllung usually has before the first use of Mahlhilfskörper in the apparatus according to the invention as uniform a diameter of Mahlhilfskörper with small deviations. The auxiliary grinding bodies have in particular a diameter, for example in the range of 0.5 to 8 mm, or 1 to 3 mm, or 0.7 to 2 mm. Thus, a Mahlhilfskörperfüllung includes Mahlhilfskörper example with a diameter of 8 mm. Another Mahlhilfskörperfüllung may Mahlhilfskörper having an exemplary diameter of 1 mm.

In the embodiment in which auxiliary grinding bodies are used, the separating device furthermore serves to retain these auxiliary grinding bodies in the first process area. Accordingly, the gap width of the separation device, both with regard to the dynamic gap and the possibly existing static gaps, must be adjusted accordingly. The gap width therefore preferably corresponds to a maximum of the holding selected size ranges.

In order to intensify the dispersion of the solid and to support the loosening of the grinding aid in the first process area mixing tools are provided in an equally preferred embodiment in the first process area. These may be provided on the first section of the rotor unit, on the housing or on both. By way of example, the mixing tools are pins that extend perpendicularly into the first process area from the housing and / or the surface of the first section of the rotor unit. In this way, accumulation of the Mahlhilfskörper is prevented on the separator.

The mixing method according to the invention is carried out in a device according to the invention and comprises the following steps: introducing at least two substances, in particular a solid and a liquid, into the housing of the device, then mixing the at least two substances in the first process region by means of the first section of the rotating rotor unit and passing the mixture through the separation device into the downstream second process area, then dispersing the mixture in the second process area, in particular between the ejection means and a wall of the housing or other static elements, and then discharging the mixture from the second process area by means of the second section Rotor unit arranged ejector. The mixture is dispersed in the first process area by means of grinding auxiliary bodies, in particular spherical Mahlhilfskörpen, preferably intensively dispersed, wherein the dynamic and / or the static column of the separator are less than or equal to half the diameter of Mahlhilfskörper.

In the first process area, predispersion takes place. In the second process area, the dispersion is further refined and homogenized by the ejection agent. Before the first process area, a premix stage can be arranged, as will be illustrated below on the basis of exemplary embodiments.

The mixing method according to the invention has the advantages already discussed above with reference to the device. Therefore, reference is made to the illustrations of the advantages of the invention as well as the mode of operation of the embodiments.

In a preferred embodiment, before discharging the mixture, the mixing method comprises the further step of: dispersing the mixture in the second process area, in particular between the ejection means and the housing. If the distance between the ejection means and the housing chosen low enough, as described above, then it can lead to an intensification of the dispersion in this area.

In an equally preferred embodiment, the mixing method has the further step of: (intensive) dispersing the mixture in the first process area by means of spherical auxiliary bodies in particular, wherein the gaps of the separating device are preferably less than or equal to half the diameter of the auxiliary grinding bodies.

Likewise, it is preferred that the device has mixing tools in the first process area on the housing and / or on the first section of the rotor unit. With regard to the resulting advantages, reference is likewise made to the associated explanations of the device according to the invention.

• Fig. 1 eine Schnittansicht einer ersten Ausführungsform der erfindungsgemässen Vorrichtung,
• Fig. 2 eine Draufsicht auf die erste Ausführungsform der erfindungsgemässen Vorrichtung in geöffnetem Zustand,
• Fig. 3 eine Schnittansicht einer zweiten Ausführungsform der erfindungsgemässen Vorrichtung,
• Fig. 4 eine Schnittansicht einer dritten Ausführungsform der erfindungsgemässen Vorrichtung,
• Fig. 5 eine Schnittansicht einer vierten Ausführungsform der erfindungsgemässen Vorrichtung,
• Fig. 6 eine Schnittansicht einer fünften Ausführungsform der erfindungsgemässen Vorrichtung
• Fig. 7 eine Schnittansicht einer sechsten Ausführungsform der erfindungsgemässen Vorrichtung und
• Fig. 8 einen schematischen Verfahrensablauf des erfindungsgemässen Mischverfahrens.

Further advantages of the present invention will become apparent from the detailed description with reference to the figures. In the figures, like reference numerals designate like elements. Show it:

• Fig. 1 a sectional view of a first embodiment of the inventive device,
• Fig. 2 a top view of the first embodiment of the inventive device in the open state,
• Fig. 3 a sectional view of a second embodiment of the inventive device,
• Fig. 4 a sectional view of a third embodiment of the inventive device,
• Fig. 5 a sectional view of a fourth embodiment of the inventive device,
• Fig. 6 a sectional view of a fifth embodiment of the inventive device
• Fig. 7 a sectional view of a sixth embodiment of the inventive device and
• Fig. 8 a schematic process flow of the inventive mixing method.

The device according to the invention can be used in particular for mixing a solid, such as a powder, with a liquid. For example, a paint, in particular a car paint, can be produced by means of the device. Preferably, the apparatus is used to prepare mixtures that are low to medium viscosity.

Referring to the Fig. 1 and 2 the inventive device 1 is shown in a first embodiment in the sectional view and in plan view. In the following, the device 1 will be described during operation. In this case, a rotor unit of the device 1 rotates according to Fig. 2 clockwise.

The device 1 has a housing 10. The housing 10 includes a fluid inlet and a solids inlet. The supply of the liquid and the solid can be effected via corresponding lines 20, 22.

The solid may be a powder 30 held in a container 32. The liquid is for example water, oil or solvent, which is supplied in the direction of arrow A of the device 1 or is sucked by this. The suction effect of the device 1 will be explained later in detail, so that it will not be discussed further at this point.

In the housing 10 is a separation device 40, which divides the housing 10 into a first process area 12 and a downstream second process area 14. Furthermore, in the housing 10, the rotor unit 50 is arranged, which is driven via an associated drive shaft 52. The rotor unit 50 has a first section 54, which is arranged in the first process area 12, and a second section 56, which is arranged in the second process area 14.

The first portion 54 of the rotor unit 50 has a plurality of openings 58. Through the openings 58, the supplied powder 30 can be distributed together with the liquid in the entire first process area 12. Mixing of powder 30 and liquid is effected due to the rotation of the rotor assembly 50 and the openings 58 present in the first section.

During operation of the device 1, the mixture generated in the first process area 12 flows radially outwards in the direction of the separation device 40 due to the rotation of the rotor unit 50. In the present example, the separation device 40 extends perpendicularly from the bottom or cover of the housing 10 in the direction of the surface of the first section 54 of the rotor unit 50. The separation device 40 has static gaps and at least one dynamic gap. The static gaps are formed in the separator 40 itself. For example, the separator may consist of a skeleton having corresponding static gaps. The dynamic gap (s) are formed between the first portion 54 of the rotor unit 50 and the separator 40. Only a plan gap is shown. In addition, however, the first portion 54 of the rotor unit 50 may have a bead so that an axial dynamic gap is also formed between the separator 40 and the first portion 54 of the rotor unit 50. For example, both the dynamic column and the static column are less than or equal to 4 mm. In this way, effectively contained in the powder, coarse particulate foreign body can be retained become. This is, as will be explained later, particularly advantageous, since thus damage to the second portion 56 of the rotor unit 50 can be avoided.

During operation of the device, the mixture produced in the first process region 14 flows through the separating device 40 into the second process region 14.

At the second portion 56 of the rotor unit 50, an ejection means is arranged. The ejection means may be a plurality of blades 60. By means of the blades 60, a pressure difference is generated in the device 1, whereby at least the powder 30 can be sucked in automatically by the device during operation. Compared to the known devices, the device 1 according to the invention has a greater suction effect due to the ejection means. In this way, no forced conveyor are required to supply the solid of the device 1.

Furthermore, the blades 60 have a distance to the housing 10 of less than 2 mm in both the radial and in the axial direction. In this way, in addition to the mixing in the first process area 12, a dispersing between the blades 46 and the housing 10 in the second process area 14 can be realized. In addition, the blades 60 support a discharge of the mixture from the outlet 70 of the housing 10 in the direction of arrow B. The blades 60 may, in addition to the in Fig. 2 also show a curved shape, which leads to a fluidically improved behavior of the device 1.

For example, the mixture exiting the device 1 through the outlet 70 may be supplied again to the first process area 12. Alternatively, the mixture can be further processed in a subsequent work step.

Fig. 3 shows a second embodiment of the inventive device 3. In contrast to the first embodiment, which in the Fig. 1 and 2 is shown, the device 3 additionally Mahlhilfskörper 80 in the first process area 12. In addition, 50 mixing tools 82 are arranged on the first portion 54 of the rotor unit.

By means of the grinding aid bodies 80 and the mixing tools 82, in addition to a mixing of powder 30 and liquid in the first process area 12, an (intensive) dispersion up to the real comminution of aggregates, crystalline or amorphous structures can be realized. The mixing tools 82 furthermore ensure that the auxiliary grinding bodies 80 do not collect on the separating device 40 but remain in motion. Preferably, the housing 10 also has mixing tools.

The size of Mahlhilfskörper depends in particular on the substances to be processed. Usually, however, the grinding auxiliary bodies have a diameter of less than or equal to 8 mm, preferably less than or equal to 3 mm and particularly preferably less than or equal to 1 mm. In order for the separating device 40 to effectively retain the grinding aid bodies 80 in the first process area 12 in these cases, the gap width in these cases must not be greater than half the diameter of the auxiliary grinding bodies 80 used. This applies both to the dynamic gap and to any static gaps that may be present ,

Now referring to Fig. 4 a third embodiment of the inventive device 5 is shown. In this embodiment, it is a horizontal device 5, with respect to the drive shaft 52. In contrast, the embodiments of the Fig. 1 to 3 a vertical device 1, 3 represents.

Referring again to Fig. 4 For example, the basic operation of the device 5 is identical to the operation described above for the other embodiments. A difference from the embodiment according to Fig. 3 lies only in the horizontal arrangement instead of in Fig. 3 shown vertical arrangement. Furthermore, the device 5 according to Fig. 4 a supply hopper 90 for storing solid, which is supplied to the device in the direction of arrow C. The presentation hopper 90 can be shut off with a slide 92. Likewise, the liquid line 20 has a slider 94.

In addition, liquid can be supplied via a bypass line 98 to the first process area 12 on the housing side opposite the solids inlet. The one end of the bypass line 98 is arranged for this purpose on the first process area 12, while the second end of the bypass line 98 is disposed on the liquid line 20 upstream of the spool 94. The bypass line 98 also has a slide 96.

The liquid is supplied to the first process area from a liquid container 100. Likewise, the mixture from the outlet 70 is supplied to the liquid container 100. The liquid container 100 has a stirring tool 102 for stirring the liquid.

By means of the third embodiment of the device 5, the mixture can thus flow several times through the device 5, whereby the quality of the mixture to be produced can be improved and the dispersity can be set more accurately.

A fourth embodiment of the device 7 according to the invention is shown in FIG FIG. 5 shown. In this case, a metering element 34 is arranged in the solids line 22 adjacent to the feed hopper 90. The metering element 34 is, for example, a rotary valve. By means of the metering element 34, the supply of solids in the first process area 12 can be controlled in more detail.

Likewise, the device 7 on the rotor unit on a Vormischabschnitt 62. The premixing section 62 is axially spaced and disposed upstream of the first 54 and second sections 56 of the rotor assembly and is located in a premixing region 16 of the housing 10. Here, a distance of the premixing section 62 to the housing 10 is greater compared to the spacing of the first 54 and second sections During operation of the device 7, the premixing section 62 serves for pre-mixing of powder and liquid in the premixing region 16. In terms of flow, powder and liquid thus first move from the respective inlet into the premixing region 16. There, by means of the premixing section 62 Rotor unit 52 is a pre-mixing instead. From the premixing region 16, the premix flows via a separating element 42 into the first process region 14. The separating element serves in particular for retaining grinding auxiliary bodies 80. A gap width, both dynamic and static, or an opening size is therefore preferably at or below 4 mm. To this is also on the comments on the gap width in the Separator 40 referenced. With regard to the further material flow, reference is made to the above remarks in order to avoid unnecessary repetitions.

FIG. 6 shows a fifth embodiment of the device 9. Here, the first 12 and the second process area 14 are arranged axially spaced from each other. Accordingly, the first portion 54 and the second portion 56 of the rotor unit are arranged axially spaced apart. Furthermore, the second section 56 of the rotor unit openings 58. These openings are arranged distributed between the blades 60 and the drive shaft 52 of the rotor unit. The general operation of the device 9 is identical to that of the Fig. 1 to 4 described operation. For this reason, no further statements are made, but refer to the above statements.

In a sixth embodiment according to Fig. 7 the first 12 and the second process area 14 are arranged axially one above the other, as already in the exemplary embodiment Fig. 6 , Furthermore, an intermediate wall 18 is arranged in the housing between the first 12 and the second process area 14. The separator 40 is disposed on the first portion 54 of the rotor unit adjacent the drive shaft 52. Between the separator 40 and the intermediate wall 18 thus the dynamic gap is formed. The dynamic gap may be a plan gap.

The sixth embodiment is particularly advantageous, since the separation device 40 does not have to retain the auxiliary grinding bodies in the mass, as in the other embodiments. In particular, in the present embodiment, the auxiliary grinding bodies 80 are transported outwardly away from the separating device 40 as a result of the centrifugal forces acting on the auxiliary grinding bodies 80.

FIG. 8 shows the sequence of a mixing method according to the invention. The mixing method according to the invention uses the device according to the invention. In a first step I, at least two substances, in particular a solid and a liquid, are introduced into the first process area 12 of the device 1, 3, 5, 7, 9, 110.

Subsequently, in step II, the at least two substances are mixed in the first process area 12 by means of the first section 54 of the rotating rotor unit 50. If the device 1, 3, 5, 7, 9, 110 also has auxiliary grinding bodies 80 in the first process area 12, then this takes place additionally (intensively) dispersing the mixture in the first process area 12 by means of the preferably spherical grinding auxiliary bodies. As already explained in the case of the different embodiments of the device 1, 3, 5, 7, 9, 110, in this case the gaps of the separating device 40 are less than or equal to half the diameter of the auxiliary grinding bodies 80.

Subsequently, the mixture thus produced flows through the separator 40 into the downstream second process area 14 (step III). In step IV, the mixture is dispersed in the second process area 14, in particular between the ejection means and the housing 10.

Subsequently, the discharge of the mixture in step V takes place from the second process area 14 by means of the ejection means arranged on the second section 56 of the rotor unit.

Claims (13)

1. Device (1; 3; 5; 7; 9; 110) for mixing, in particular dispersing, comprising

   a) a housing (10), which has at least one, preferably two, inlets and at least one outlet (70),

   b) a separating device (40), which is arranged in the housing (10) and which can be used to divide the housing (10) into a first process region (12) and a second process region (14), wherein the separating device (40) comprises static and/or dynamic gaps, and also

   c) a rotor unit (50), which is arranged rotatably in the housing (10), wherein

   d) the first process region (12) has a first portion (54) of the rotor unit (50), such that, during operation of the device (1; 3; 5; 7; 9; 110), mixing, in particular dispersing, of materials fed through the at least one, preferably the two, inlets can be carried out by means of the first portion (54) of the rotor unit (50) in the first process region (12), and

   e) the second process region (14) is arranged downstream of the first process region (12), after the separating device (40), and comprises a second portion (56) of the rotor unit (50), and

   f) the rotor unit comprises a rotor disc, which extends through elements of the separating device and forms a dynamic gap therewith, and

   g) the second portion (56) of the rotor unit (50) comprises an ejection means,

   h) wherein the second process region (14) and the second portion (56) are formed in such a manner that dispersion can be achieved, characterized in that

   i) auxiliary grinding bodies (80), in particular spherical auxiliary grinding bodies, are arranged in the first process region (12).
2. Device (1; 3; 5; 7; 9; 110) according to Claim 1, wherein the ejection means is formed on the second portion (56) of the rotor unit (50) in such a manner that, during intended operation, it sweeps past static elements of the device, in particular the housing (10), at a distance of less than 20 mm, preferably less than 15 mm, particularly preferably less than 5 mm.
3. Device (1; 3; 5; 7; 9; 110) according to either of the preceding claims, wherein the rotor unit (50) has a substantially circular cross section perpendicular to the axis of rotation and extends through the separating device (40), or the first portion (54) and the second portion (56) of the rotor unit (50) are spaced apart axially from one another.
4. Device (1; 3; 5; 7; 9; 110) according to one of the preceding claims, wherein a suction effect can be generated at the at least one inlet by means of the ejection means during operation of the device (1; 3; 5; 7; 9; 110).
5. Device (1; 3; 5; 7; 9; 110) according to one of the preceding claims, wherein the ejection means comprises a plurality of blades (60) or paddles.
6. Device (1; 3; 5; 7; 9; 110) according to one of the preceding claims, wherein

   - elements of the separating device (40) are fastened on the housing (10), as a result of which a dynamic gap is formed between these elements of the separating device (40) and the rotor unit (50), in particular the first portion (54) of the rotor unit (50);

   - or elements of the separating device (40) are fastened on the rotor unit (50), in particular on the first portion (54) of the rotor unit (50), as a result of which a dynamic gap is formed between these elements of the separating device (40) and the housing (10).
7. Device (1; 3; 5; 7; 9; 110) according to one of the preceding claims, wherein the separating device (40) has a plurality of static gaps formed in the separating device (40).
8. Device (1; 3; 5; 7; 9; 110) according to either of Claims 6 and 7, wherein the dynamic gap and/or the static gaps are smaller than or equal to 4 mm, preferably smaller than or equal to 3 mm, particularly preferably smaller than or equal to 2 mm.
9. Device (1; 3; 5; 7; 9; 110) according to Claim 1, wherein the dynamic gap and/or the static gaps are smaller than or equal to half the diameter of the auxiliary grinding bodies (80).
10. Device (1; 3; 5; 7; 9; 110) according to one of the preceding claims, wherein the first portion (54) of the rotor unit (50) and/or the housing (10) has mixing tools (82) in the first process region (12).
11. Device (1; 3; 5; 7; 9; 110) according to one of the preceding claims, wherein at least one solid, in particular a powder, and a liquid can be fed to the device (1; 3; 5; 7; 9; 110) for mixing.
12. Method for mixing, in particular dispersing, comprising the following steps using a device (1; 3; 5; 7; 9; 110) according to one of Claims 1 to 11:

    a) introducing (I) at least two materials, in particular a solid and a liquid, into the housing (10) of the device (1; 3; 5; 7; 9; 110), thereafter

    b) mixing (II) the at least two materials in the first process region (12) by means of the first portion (54) of the rotating rotor unit (50), and

    c) guiding (III) the mixture through the separating device (40) into the downstream, second process region (14),

    d) dispersing (IV) the mixture in the second process region (14), in particular between the ejection means and a wall of the housing (10) or other static elements, and subsequently

    e) discharging (V) the mixture out of the second process region (14) by means of the ejection means arranged on the second portion (56) of the rotor unit (50), wherein,

    in step b), the mixture is dispersed, preferably intensively dispersed, in the first process region (12) by means of auxiliary grinding bodies (80), in particular spherical auxiliary grinding bodies, wherein the dynamic gap and/or the static gaps of the separating device (40) are smaller than or equal to half the diameter of the auxiliary grinding bodies (80).
13. Mixing method according to Claim 12, wherein the device (1; 3; 5; 7; 9; 110) has mixing tools (82) in the first process region (12) on the housing (10) and/or on the first portion (54) of the rotor unit (50).

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