EP2285476B1 - Rotor/stator system and process for producing dispersions - Google Patents

Description

The invention relates to a rotor-stator system and to a method for producing and / or treating dispersions. The invention relates to the preparation and / or treatment of dispersions in general and of emulsions in particular.

The term "dispersion" is understood to mean a multiphase system which comprises at least components which are substantially insoluble in one another. In particular, dispersions comprise emulsions in which a liquid in the form of drops is distributed in another liquid. The phase which forms the drops is called a disperse phase or inner phase. The phase in which the drops are distributed is referred to as continuous phase or outer phase.

Dispersions further include suspensions in which solid particles are dispersed in a liquid continuous phase. In addition, material systems which have both solid and liquid phases in dispersed form also belong to dispersions. For example, a solid could be dispersed in a first liquid, which suspension forms the disperse phase of an emulsion. Also in the continuous phase of emulsions, solids can be distributed. One speaks in this connection of suspoemulsions.

If two liquids which are essentially insoluble in one another are mixed with one another so that each of the two phases is accessible, the corresponding substance system is referred to as a mixture. A mixture can be diluted by adding both one and the other phase. In contrast, in an emulsion, the disperse phase is not accessible from the outside; An emulsion can only be diluted by adding the continuous phase. In the preparation of an emulsion, a mixture may occur as an intermediate.

In the following, the term "component" refers in particular to a phase of a dispersion. But a component can also be part of a phase. For example, a phase can be formed from a plurality of, in particular, soluble components.

When preparing dispersions, in particular when preparing emulsions, it is important for obtaining an end product with the desired properties in terms of the size distribution of the disperse phase, the flow behavior and the stability of the product against thermal and mechanical stress as well as temporal changes that the necessary steps of the Introduction of the inner phase in the outer phase for preparing a pre-mix, the fine dispersion and the stabilization of the product obtained process-defined and performed reliably. From the kitchen one knows the appropriate process by the production of a Mayonnaise. The oil phase is slowly stirred into the water phase. The result is first a coarse emulsion with low viscosity as a pre-mix. By further rapid stirring, the emulsion becomes finer and the viscosity increases. Industrially dispersions in particular emulsions by various Processes made. Which process is selected depends on the nature of the dispersion and on the fineness of the disperse phase with which a stable dispersion over the required period of time can be obtained. A stable dispersion is understood as meaning a substance system whose article size distribution of the disperse phase and / or its flow behavior, in particular its viscosity, does not substantially change over a given period of time.

For the industrial production of dispersions, containers with an agitator, for example a doctor blade stirrer or a stirrer turbine, are frequently used for relatively coarse dispersions. For finer dispersions, two-stage processes are used, in which a pre-mix is first prepared in a vessel with stirrer, followed by a passage through a rotor-stator dispersing machine. This can be for example a Koloidmühle. Particularly fine dispersions can be achieved by dispersing in a high-pressure homogenizer as an additional process step.

To prepare a fine dispersion with a rotor-stator system from a pre-mix, which was prepared in a container with agitator, it is generally assumed that a dispersion having a very broad particle size distribution. As an example, consider an emulsion having a droplet size distribution between 30 and 500 microns. With a conventional rotor-stator system (see. FIG. 11 , see description below) are the drops of the pre-mix, which in the case of an emulsion is also referred to as crude emulsion is crushed until an average droplet size is reached, the specific energy input of the rotor-stator system (Energy density) corresponds. In order to achieve a relatively narrow droplet size distribution with droplet diameters between 5 and 10 microns and below, several passes through the rotor-stator system are usually required. Often 5 to 10 runs are needed. This means on the one hand a high stress of the product and on the other hand a high heat input and thus an inefficient utilization of the energy used.

To speed up the process described above, some dispersing machine manufacturers have begun to deliver the inner phase via feeds such as pipes or bores directly in front of the rotor teeth or on the rotor teeth of a rotor-stator system. Such rotor-stator systems are in WO 00/01474 and US 5,590,961 described. The inner phase comes locally very limited and thus in a relatively massive beam in the rotor-stator system and its dispersion. This results in the first pass through the rotor-stator system, an emulsion which has a broad droplet size distribution, since the inner phase can not be sufficiently finely incorporated into the outer phase, since it lacks in exchange in the locally very limited area of contact. In addition, the emulsion is highly exposed to coalescence, since small volumes of small droplets are formed on a narrow volume, but they can not be removed and stabilized quickly enough to coalesce again. Even a related streaking can be observed. The coalescence and streaking increase as the addition volume of the inner phase increases. In this way, small amounts of the inner phase can be introduced into the outer phase. Significant problems, however, exist when larger amounts of internal phase have to be introduced.

The difficulties are mainly due to the fact that it is not possible to produce a homogeneous crude emulsion or a homogeneous pre-mix with a definable particle size distribution of the outer and inner phase before the phases reach the zones of high shear forces of the rotor-stator system.

In WO 01/56687 ( PCT / EP00 / 117700 ) describes a rotor-stator system whose rotor has a premixing chamber. The premix chamber opens into several small chambers located on the rotor circumference. All chambers act together as a premixing chamber in the rotor, which is located in the dispersion chamber and rotates during operation of the rotor-stator system. However, due to the geometry of the rotor and resulting volume available as premixing chamber, the amount of internal phase which can be introduced into the external phase is very limited. The positioning of the premixing chamber in the rotor, and thus in the moving part of the rotor-stator system, makes the production of dispersions having complex compositions and different components, which in some cases should be simultaneously incorporated into an existing master, extremely complicated, if not impossible.

U.S. 5,590,961 discloses a rotor-stator system according to the preamble of claim 1.

The invention is therefore based on the object to provide a structurally simple way to be able to produce stable dispersions in a rotor-stator system even with a single pass. It is a further object of the invention to provide a way to react flexibly to changing requirements with regard to the composition of the dispersion to be produced with a rotor-stator system. In addition, it is an object of the invention to provide a rotor-stator system, which a variety possible generate energetic vortex in turbulent flow, to crush particles of the disperse phase of a dispersion efficiently.

These objects are achieved in a surprisingly simple manner, with a rotor-stator system according to claim 1.

The invention provides a rotor-stator system for preparing and / or treating dispersions according to claim 1.

In one development of the invention, the rotor-stator system has at least two premixing chambers, each of which has an inlet for feeding a component of the dispersion from outside the stator into the relevant premixing chamber. Thus, either another component can be supplied via each premixing chamber. Or a large amount of a component may be supplied in divided form over several premix chambers. In any case, the Increased efficiency of the mixing process compared to a supply of the components directly into the dispersion.

According to a further advantageous embodiment, the premixing chamber bulges into the stator from the transition to the dispersion region. The domed shape allows easy and reliable cleaning of the premixing chamber. In addition, the formation of dead spaces is avoided, which can have a negative effect on the mixing effect in the premixing chamber.

The invention also provides that the premixing chamber at the transition to the dispersing region may have the form of a strip-shaped section of a circle segment, wherein the section has, in particular, a circumferentially continuous curve. Also by this design corners are avoided, which accommodates, among other things, the easy cleanability.

The invention also offers the advantage of being able to adapt the flow guidance of the dispersion in the dispersing region to the respective process requirements with the position of the premixing chambers. In a further development of the invention it is provided that the transition of the premixing chamber to the dispersing at a radial distance from the longitudinal axis of the stator, which corresponds to the axis of rotation of the rotor corresponding to the stator is mounted, that the premixing above a dispersing tool, in particular a ring gear of the Rotor is positioned when the stator is combined with the corresponding rotor to the rotor-stator system. The Vormischkammern can thus be mounted over the sprocket of a rotor with a sprocket.

A premixing chamber may be mounted over the inner sprocket, over the outer sprocket, or over multiple sprockets, in a multi-sprocket rotor. Accordingly, the transition of the premixing chamber to the dispersing region is positioned at a radial distance from the longitudinal axis of the stator corresponding to the axis of rotation of the rotor corresponding to the stator such that the premixing chamber is positioned at least above the internal dispersing tool, in particular the inner sprocket of a multi-dispersing rotor is when the stator is combined with the corresponding rotor to the rotor-stator system.

In an advantageous development, the invention further provides a rotor-stator system having Vormischkammern which are positioned at different radial distances to the longitudinal axis of the stator. In this way, for example, a stator is provided for use with a rotor having at least one inner and one outer ring gear, wherein at least one premixing chamber is positioned over the inner ring gear of the rotor and at least one further premixing chamber is positioned over the outer ring gear of the rotor, when the stator is used together with the rotor.

If premixing chambers are provided both above the inner and outer sprockets of the rotor, in a single pass through the rotor-stator system, relatively high viscosity media can be externally added and media of relatively low viscosity can be externally added. This offers advantages, for example, when dispersing low-viscosity media such as perfume or preservatives on the one hand and during dispersion of higher viscosity fluids and / or larger resulting drop sizes, on the other hand.

The fluids added via the premixing chambers closer to the center axis are generally dispersed to smaller droplets with the same parameters, in particular with the same flow behavior of the fluids, than the fluids added via further outermost premixing chambers, since the path through the dispersing chamber is for them continues. As a result, the internally introduced fluids are exposed longer to the dispersing effect of the rotor-stator system.

In order to be able to further influence the flow at the transition between the premixing chamber and the dispersion chamber, a transition piece is arranged according to the invention between the premixing chamber and the dispersing region. During operation of the rotor-stator system, fluid is injected from the premixing chamber into the dispersing chamber and ejected from the dispersing chamber into the premixing chamber. In the following, the transition piece is also referred to as an injector or ejector. Depending on the application, the transition piece may partially or completely fill the transition between the premixing chamber and the dispersing region.

In accordance with the advantageous geometry of the premixing chamber, the transition piece in one embodiment of the invention has the form of a strip-shaped section of a circular segment. The transition piece can then have a curved peripheral line so that it is exactly adapted to the shape of the premixing chamber at its transition to the dispersion chamber.

For a particularly good mixing of the liquid at the transition between the premixing chamber and the dispersion chamber is further provided that the transition piece is designed according to the invention in the manner of a perforated plate and having one or more circular and / or polygonal openings and / or a slot or more slots as holes , Preferably, a plurality of slots each extending substantially transverse to the main extension direction of the transition piece.

The flow conditions in the vicinity of the transition piece can also be influenced by the direction of orientation of the holes in the transition piece. The invention provides in a further embodiment that the holes each extend through the transition piece along a hole axis which forms an angle with the perpendicular to the transition piece, in particular an angle in the range between about 10 ° and about 80 °, preferably in the range between about 30 ° and about 60 ° and most preferably an angle of about 45 °.

In addition, the holes through the transition piece may have a tapered shape from one to the other side of the transition piece to enhance the injector or ejector action. In particular, the invention provides that the holes are delimited by a lateral surface having a first partial region and at least one further partial region, wherein at least one partial region runs along a sectional surface which encloses an angle with the perpendicular to the transition piece, in particular an angle in the region between about 10 ° and about 80 °, preferably in the range between about 30 ° and about 60 ° and most preferably an angle of about 45 °.

In order to enable in a simple manner a flexible adaptation of the rotor-stator system to different dispersing tasks, it is further provided to form the stator in two parts. The stator then comprises a stator head and a stator body, wherein the at least one premixing chamber is arranged in the stator head and the stator body comprises a dispersing tool of the stator, in particular at least one ring gear.

In this way, for example, a stator for retrofitting existing rotor-stator systems can be created. Such a stator comprises a plurality of stator heads, which differ in number and / or geometry of the premixing chambers and can be mounted on a stator fuselage to form a stator with exchangeable stator head.

A particularly simple design is realized by the premixing chamber is formed as a cavity in the stator head such that a transition piece can be mounted as a conclusion of the cavity on the stator head.

The apparatus component which contains the premixing chamber includes is in the assembled state an integral part of the housing.

The invention further relates to a process for preparing and / or treating dispersions under Use of a rotor-stator system according to claim 7.

With the method according to the invention, it becomes possible to add at least one phase or one component of a dispersion in the small volume of a premixing chamber in relation to the dispersion space. Thus, a pre-mix of the components is fed to the dispersion, wherein already the components of the pre-mix are homogeneously distributed.

According to the invention, advantageously, the throughput of the components and the rotational speed of the rotor can be adjusted and / or regulated and / or controlled, that the Residence time in a pre-mixing chamber ranges between about 0.005 seconds and about 0.02 seconds. The formation of the pre-mix within this short period of time and its further transport into the dispersion space counteract the coalescence of the disperse phase fluid elements formed in the premixing chamber.

According to an advantageous development of the method, a stator is used with at least one further premixing chamber and in step a) at least one further phase of the dispersion is provided in at least one further feed tank, which communicates with the further premixing chamber. In step c), the further phase of the dispersion is fed into the further premixing chamber of the rotor-stator system, so that during operation of the rotor-stator system, the first phase passes through the dispersing space and optionally through the transition piece in the premixing chambers and in contacting the respective premixing chamber with the second or further phase, wherein a mixture and / or a dispersion of the phases is formed, and wherein the second or at least one further phase and / or the mixture and / or the dispersion formed in a premixing chamber from at least two phases is conveyed through the respective premixing chamber and optionally through the respective transition piece in the dispersion.

By metering in via a plurality of spatially separate premix chambers, a parallel operation of the premix chambers becomes possible. In addition, the individual components can each be separately subjected to a premix before they are fed to the dispersion. The equalization of the mixing process of all components of the dispersion by dividing the admixing of the Components via premix chambers improve the mixing process according to the invention over known processes.

In one embodiment of the method, steps b), c) and d) are carried out simultaneously. So the process can be operated continuously.

In order to introduce the larger amount of disperse phase into the smaller amount of continuous phase, in particular for the production of dispersions with a high disperse phase fraction of more than 50% by volume, the process according to the invention offers the advantage of supplying the disperse phase as first in step b) Phase and supplying the continuous phase or a component of the continuous phase of the dispersion as fed in step c) second phase and undergoing a phase inversion in the preparation of the dispersion by the dispersion on the one hand due to the mixing action and the crushing effect of the rotor-stator system and on the other in addition to be able to produce particularly homogeneous dispersions by the rearrangement of the fluid elements in the inversion of the phases, even if the disperse phase fraction is high.

Compared to dispersions prepared without phase inversion, these dispersions have a narrower particle size distribution. These advantages are particularly valuable in the preparation of dispersions with a high disperse phase content, since there due to the high density of particles, especially drops (in emulsions) of the disperse phase, the risk of coalescence is large. Coalescence destroys the mixture or comminution of the disperse phase. The advantages However, the phase inversion can also be used in dispersions with a lower disperse phase fraction.

Fig. 1

das Rotor-Stator-System gemäß einer ersten Ausführungsform der Erfindung in eingebautem Zustand in eine Dispergiermaschine im Querschnitt,

Fig. 2

einen Ausschnitt aus einer Fotografie eines Statorkopfes, wobei der Ausschnitt eine Vormischkammer zeigt,

Fig. 3

eine Fotografie eines Übergangsstücks, wobei das Übergangsstück auf einer Unterlage liegt, welche die Geometrie eines Rotorzahns veranschaulicht,

Fig. 4

eine Fotografie eines Übergangsstücks wobei das Übergangsstück auf einer Unterlage liegt, welche die Geometrie eines Rotorzahns veranschaulicht,

Fig. 5

eine Fotografie eines Statorkopfes mit einer Vormischkammer, an deren Übergang zum Dispergierbereich im komplett montierten Zustand des Statorkopfes ein Übergangsstück eingeschweißt ist,

Fig. 6

verschiedene Gestaltungen von Übergangsstücken , nämlich in

Fig. 6a

eine Aufsicht auf ein Übergangsstück mit schematisch angedeuteten Geometrien für die Anordnung von Schlitzen B10) und A10), in

Fig. 6b

Ausschnitte aus Querschnitten durch Übergangsstücke gemäß weiteren Ausführungsformen der Erfindung, zu welchen als Verständnishilfe jeweils ein Ausbruch aus einem Rotorzahn dargestellt ist, mit unterschiedlichen Gestaltungen der Löcher im Übergangsstück A11, B11, C11, A12 und B12, und in

Fig. 6c

eine Aufsicht auf den Übergang zwischen Vormischkammern und dem Dispergierraum des Rotor-Stator-Systems, für welchen oben schematisch Zähne des inneren Rotorkranzes angedeutet sind. Dargestellt sind Geometrien A15, B15, C15 und D15 für Größe der Vormischkammer und Gestaltung von Übergangsstücken (A15, B15), wie sie miteinander kombiniert oder alternativ eingesetzt werden können. Zur Orientierung ist in Fig. 6c rechts unten ein schematischer Schnitt durch eine Vormischkammer eingezeichnet.

Fig. 7

eine schematische Darstellung der Passage von zu behandelndem Fluid bei der Herstellung von Dispersionen mit Vormischkammer und Dispergierraum im Querschnitt,

Fig. 8

eine Fotografie der Seitenansicht eines Stators,

Fig. 9

Zahnkränze für einen Stator in Querschnitt und Aufsicht,

Fig. 10

Fotografie eines Stators mit zwei Vormischkammern und zwei Zahnkränzen sowie eines Rotors mit einem inneren und einem äußeren Zahnkranz, wobei der Rotor und der Stator ein Rotor-Stator-System gemäß einer Ausführungsform der Erfindung bilden,

Fig. 11

eine Fotografie eines Stators mit zwei Zahnkränzen (rechts) und eines Rotors mit mehreren schräg angeordneten Zähnen (links) eines herkömmlichen Rotor-Stator-Systems,

Fig. 12

einen Rotor (vergleiche Fig. 10 unten) in Querschnitt und Aufsicht (linke Seite in Fig. 12) mit einer vergrößerten Detaildarstellung eines Rotorzahns im Querschnitt (rechts oben in Fig. 12),

Fig. 13

einen Rotor (vergleiche Fig. 10 unten) in Querschnitt und Aufsicht (linke Seite in Fig. 13) mit einer vergrößerten Detaildarstellung eines Rotorzahns im Querschnitt (rechts oben in Fig. 13),

Fig. 14

einen Rotor (vergleiche Fig. 10 unten) in Querschnitt und Aufsicht (linke Seite in Fig. 14) mit einer vergrößerten Detaildarstellung eines Rotorzahns im Querschnitt (rechts oben in Fig. 14),

Fig. 15

einen Rotor (vergleiche Fig. 10 unten) in Querschnitt und Aufsicht (linke Seite in Fig. 15) mit einer vergrößerten Detaildarstellung eines Rotorzahns im Querschnitt (rechts oben in Fig. 15),

Fig. 16

einen Rotor (vergleiche Fig. 10 unten) in Querschnitt und Aufsicht (linke Seite in Fig. 16) mit einer vergrößerten Detaildarstellung eines Rotorzahns im Querschnitt (rechts oben in Fig. 16),

Fig. 17

Schnittdarstellungen weiterer Formen für Rotorzähne

Fig. 18

eine schematische Darstellung zur Illustration einer Modellvorstellung der Passage einer Emulsion durch den Dispergierraum eines Rotor-Stator-Systems,

Fig. 19

eine schematische Darstellung einer Modellvorstellung zum Herstellen einer Emulsion während des Durchlaufs durch ein erfindungsgemäßes Rotor-Stator-System,

Fig. 20

eine schematische Darstellung einer Modellvorstellung zur Bäcker-Transformation,

Fig. 21

eine schematische Darstellung einer Modellvorstellung zum Tropfenaufbruch unter der sogenannten Bäker-Transformation während eines einmaligen Durchlaufs durch ein erfindungsgemäßes Rotor-Stator-System,

Fig. 22

eine schematische Darstellung einer Vormischkammer gemäß einer weiteren Ausführungsform der Erfindung, welche in ein Pumpengehäuse eingeschweißt werden kann,

Fig. 23

eine schematische Darstellung einer Vorderansicht einer Pumpe mit Pumpengehäuse, in welcher eine Vormischkammer angeordnet ist (vgl. Fig. 22).

The invention will be explained in more detail below with reference to the accompanying drawings with reference to embodiments. The same components are provided with the same reference numerals in all drawings. Show it:

Fig. 1

the rotor-stator system according to a first embodiment of the invention in the installed state in a dispersing machine in cross-section,

Fig. 2

a section of a photograph of a stator head, wherein the section shows a premixing chamber,

Fig. 3

a photograph of a transition piece, wherein the transition piece lies on a base, which illustrates the geometry of a rotor tooth,

Fig. 4

a photograph of a transition piece with the transition piece lying on a base which illustrates the geometry of a rotor tooth,

Fig. 5

a photograph of a stator head with a premixing chamber, at the transition to the dispersion area in the completely assembled state of the stator head, a transition piece is welded,

Fig. 6

various designs of transition pieces, namely in

Fig. 6a

a plan view of a transition piece with schematically indicated geometries for the arrangement of slots B10) and A10), in

Fig. 6b

Excerpts from cross sections through transition pieces according to further embodiments of the invention, to which an outbreak from a rotor tooth is shown as an aid to understanding, with different configurations of the holes in the transition piece A11, B11, C11, A12 and B12, and in

Fig. 6c

a plan view of the transition between premixing chambers and the dispersing space of the rotor-stator system, for which above schematically teeth of the inner rotor rim are indicated. Illustrated are geometries A15, B15, C15 and D15 for size of the premix chamber and design of transition pieces (A15, B15) as they may be combined together or alternatively employed. For orientation is in Fig. 6c at the bottom right a schematic section through a premixing chamber drawn.

Fig. 7

a schematic representation of the passage of fluid to be treated in the preparation of dispersions with premixing and dispersing in cross-section,

Fig. 8

a photograph of the side view of a stator,

Fig. 9

Sprockets for a stator in cross-section and supervision,

Fig. 10

Photograph of a stator with two premix chambers and two sprockets and a rotor with an inner and an outer sprocket, wherein the rotor and the stator form a rotor-stator system according to an embodiment of the invention,

Fig. 11

a photograph of a stator with two sprockets (right) and a rotor with a plurality of obliquely arranged teeth (left) of a conventional rotor-stator system,

Fig. 12

a rotor (see Fig. 10 below) in cross section and top view (left side in Fig. 12 ) with an enlarged detail of a rotor tooth in cross section (top right in Fig. 12 )

Fig. 13

a rotor (see Fig. 10 below) in cross section and top view (left side in Fig. 13 ) with an enlarged detail of a rotor tooth in cross section (top right in Fig. 13 )

Fig. 14

a rotor (see Fig. 10 below) in cross section and top view (left side in Fig. 14 ) with an enlarged detail of a rotor tooth in cross section (top right in Fig. 14 )

Fig. 15

a rotor (see Fig. 10 below) in cross section and top view (left side in Fig. 15 ) with an enlarged detail of a rotor tooth in cross section (top right in Fig. 15 )

Fig. 16

a rotor (see Fig. 10 below) in Cross section and supervision (left side in Fig. 16 ) with an enlarged detail of a rotor tooth in cross section (top right in Fig. 16 )

Fig. 17

Sectional views of other forms for rotor teeth

Fig. 18

a schematic representation for illustrating a model of the passage of an emulsion through the dispersing space of a rotor-stator system,

Fig. 19

a schematic representation of a model for preparing an emulsion during the passage through a rotor-stator system according to the invention,

Fig. 20

a schematic representation of a model presentation on the baker's transformation,

Fig. 21

2 is a schematic representation of a model idea for droplet breakup under the so-called Bäker transformation during a single pass through a rotor-stator system according to the invention;

Fig. 22

1 is a schematic representation of a premixing chamber according to a further embodiment of the invention, which can be welded into a pump housing,

Fig. 23

a schematic representation of a front view of a pump with pump housing, in which a premixing chamber is arranged (see. Fig. 22 ).

FIG. 1 shows an overall view of a dispersing machine with a rotor-stator system according to the invention. In a first storage tank 101, a first phase of a dispersion to be prepared can be submitted. Through the inlet 8, this phase can get into the dispersion of the rotor-stator system, which of the rotor 4 and the stator 1 is formed. Through feeds 25, a further phase of the dispersion in Vormischkammern 2, which are located in the head 11 of the stator, are supplied. In FIG. 1 a rotor-stator system with two premix chambers is shown. By means of the inlets 25, half of the second phase to be supplied in total can be introduced either into each of the two premixing chambers 2, or different components can be introduced into the dispersion to be prepared simultaneously via a respective inlet 25 and a premixing chamber 2.

The rotor 4 can be driven by a motor 116 via the drive shaft 115. The teeth of the rotor 4 then rotate adjacent to the teeth of the stator and under the transition between the premixing chambers 2 and the dispersing space of the rotor-stator system. During operation of the rotor-stator system, the dispersion is exposed to shear stresses in the dispersing chamber as well as in the premixing chambers and at the transition between the premixing chambers and the dispersing chamber. Furthermore, at least partially turbulent flow conditions are generated. During the passage of the premixing chamber, the transition between the premixing chamber and the dispersion chamber and the dispersion chamber itself, the disperse phase of the dispersion is comminuted.

The dispersing space is surrounded on the outside by an annular channel 112, which is delimited by the housing 113 of the dispersing machine. From the annular channel 112, the dispersion can be withdrawn through an outlet 9 from the dispersion.

Gaskets 117 and 118 designed as a mechanical seal, that is as a rotating mechanical seal, or as a static seal, that is, for example, as an O-ring can separate the dispersion from the other driven or moving components of the dispersing machine.

In FIG. 2 is a view from below from the dispersing seen in a premixing chamber 2 to see. The premixing chamber 2 is formed as a cavity in the interior of the stator head 11. The premixing chamber 2 has a curved circumferential line 28. The premixing chamber 2 is formed curved into the interior of the stator head 11. That is, the shape of the premixing chamber 2 is designed such that substantially no corners and edges are present. This allows a particularly simple and reliable cleaning of the premixing chamber.

In FIG. 2 Furthermore, the inlet 25 can be seen, through which a second phase can be fed into the premixing chamber. The first phase may enter through the premixing chamber through the transition of the premixing chamber to the dispersing space (not shown) delimited by the circumferential line 28. At the transition between premixing chamber 2 and dispersing space of the rotor-stator system is in the in FIG. 2 shown representation no transition piece mounted.

In the Figures 3 and 4 embodiments of transition pieces are shown, which can be installed between the premixing chamber and the dispersion. In the simplest case, such transition pieces are welded as a closure of the premixing chamber towards the dispersion in the stator head. Depending on the dispersing task, the geometry of such transition pieces can be specifically selected in terms of width, shape and position relative to the rotor teeth in order to enable an optimum dispersion process.

In FIG. 3 is a transition piece with slot-shaped holes shown. α ₆ is the angle by which the front surface of a rotor tooth lying in the direction of rotation is inclined backwards relative to the radial (cf. FIG. 12 ). An arrangement of slots as in FIG. 3 shown substantially parallel to the front of a rotor tooth ensures a good penetration depth of the injected through the transition piece in the premixing fluid from the dispersion. Compared with other arrangements (see FIG. 4 ) are achieved in the premixing while flow conditions with relatively little turbulence.

This in FIG. 4 illustrated transition piece has slot-shaped openings 31, which compared to the main extension direction 32 of the transition piece 3 compared with the embodiment in FIG. 3 are inclined in the other direction. As a result, the slots 31 also extend inclined to the front side 53 of the rotor tooth 5, which is inclined by the angle α6 relative to the radial. This arrangement brings a good penetration depth of the dispersion chamber from the mixing chamber 3 into the premixing chamber 2 and from the premixing chamber into the dispersion chamber ejected fluid.

At the same time compared to the flow conditions, which with a transition piece as in FIG. 3 shown, generates flow conditions with relatively strong turbulence, since at the passage of the leading edge of the rotor tooth fluid in at least two injector slots 31 is conveyed simultaneously. As a result, different opening cross sections of the slots 31 per unit time happens, resulting in a pulsating flow in the transition piece 3 adjacent areas.

The number, dimensions and shape of the openings 31 can be selected flexibly depending on the dispersing task. With differently shaped transition pieces then a stator head according to the invention can be easily adapted to different dispersing tasks. For example, the width of the webs 39 between the slots 31 in the similar range as the width of the slots 31 measured in the main extension direction 32 of the transition piece 3 can be selected.

In FIG. 5 is a stator head 11, as seen from the side of the dispersing space of the rotor-stator system shown. In the illustrated embodiment, the stator head 11 has a premixing chamber 2. The premixing chamber 2 is bounded by a transition piece 3 at its transition to the dispersion space. The transition piece completely fills the opening of the premixing chamber 2 towards the dispersion space. The outer contour of the transition piece 3 substantially coincides with the curved peripheral line 28 of the transition of the premixing chamber 2 to the dispersion chamber. In the FIG. 5 embodiment shown is not identical to in FIG. 1 illustrated variant of the invention, because there is shown an embodiment with two Vormischkammern.

The premix chambers can be defined in number, geometry of the injectors / ejectors, their size and their location according to the process requirements. For example, for a dispersing machine having a nominal power of 30 kW, four premix chambers may be placed above the inner rotor rim at a volume for a premixing chamber of about 24 cm ³ .

The invention thus makes it possible to make an adaptation according to the respective dispersing task on the product by means of the particles placed outside the dispersing space and without moving parts, that is to say statically acting premixing chambers. In particular, several components can be processed simultaneously but spatially separated. For example, depending on the recipe, several premix chambers can be installed above each rotor ring via a replaceable stator head. Thus, in particular for the continuous dispersion of various raw materials, the extent of the shearing and / or stretching forces which are to act on the respective raw material can be varied. If very large quantities of raw materials are to be introduced, the same raw material can be added in smaller single-volume streams via several premixing chambers.

The raw materials or components of the dispersion are introduced through the premixing chambers via pumps. At the enemas 25 corresponding lines are created. Through these lines can from corresponding storage containers 102 (see FIG. 1 ) are introduced, for example via metering pumps, gear pumps or similar conveyors, the components of the dispersion in the premixing chambers.

The proportion of the phase or phases which are fed to the dispersion chamber via the premixing chambers, depends on the setting of the pumps used and can usually be preselected via a frequency converter, for example in combination with a flow meter.

Also, the size of the premixing chambers themselves and thus the contact volume between the phases, which in the Premixing can be brought into contact with each other, can be varied to adapt the geometry of the stator head to different dispersing tasks. By changing the stator head containing the premixing chambers, the number, location and size of the premixing chambers and the injectors / ejectors and their arrangement can be adapted quickly to the respective process requirements.

The number of premixing chambers is chosen depending on the number of raw materials or components which are to be introduced simultaneously or with a time offset. The size of the premixing chambers and / or the geometry of the holes in the transition piece can be chosen in accordance with the particle size distribution which is to be achieved by the treatment in the premixing chamber and when passing through the transition piece.

The coordination of these parameters to the respective dispersing task is important for the preparation of stable dispersions. By this vote, for example, can be prevented in the production of emulsions that high concentrations of freshly formed droplets of disperse phase occur in those areas in which the flow conditions do not remove the drops sufficiently quickly from each other, so that the drops coalesce after their formation again.

The domed design of the premix chamber (cf. FIG. 2 ) allows on the one hand a very good mixing of the phases and on the other hand an easy cleaning of the premixing chamber. This is achieved by dispensing with sharp corners and edges to which product could adhere or which could lead to the formation of dead spaces. As a result, the substantially complete drainage of the rinse water is facilitated.

In addition to the possibilities of variation offered by the premixing chambers themselves, the design of the transition pieces can additionally influence the flow conditions which occur during operation of the rotor-stator system. In FIG. 6 are shown for the transition pieces various embodiments.

In FIG. 6 a is shown a plan view of a transition piece, in which, for example, two different geometries for the formation of the inlet / outlet ports 31 is shown. The geometry A10 corresponds to that in FIG. 4 shown embodiment of the transition piece. The geometry B10 corresponds to that in FIG. 3 illustrated geometry of the transition piece.

In addition to the alignment of the holes or slots 31 in relation to the main extension direction 32 of the transition piece 3 and the design of the holes in their passage through the thickness of the transition piece plays perpendicular to the in FIG. 6a represented level of the transition piece a role. For the influence on the flow conditions in the vicinity of the transition piece.

In FIG. 6b different channel shapes are shown for the holes in transition pieces. A11 is currently showing through holes. This form is in the in the Figures 3 and 4 realized transition pieces realized. The penetration depth (penetration depth) of fluid from the dispersion chamber into the premixing chamber is relatively large with this geometry A11.

The holes 31 in the transition piece 3 are bounded by a lateral surface 35. According to the embodiments B11 and C11, the holes are slanted through the transition piece drilled. The hole axis 33 is inclined relative to the perpendicular to the transition piece. The inclination is in the range up to about 45 °. According to embodiments A12 and B12, the lateral surface of the holes has different regions 36, 37. A first subregion of the lateral surface 36 extends inclined relative to the perpendicular to the transition piece 3. A second region 37 of the lateral surface extends parallel to the perpendicular to the transition piece 3.

Due to the hole axis inclined with respect to the perpendicular to the transition piece, geometries B11 and C11 have a lower penetration depth. However, this ensures an increased turbulence of the fluid in the vicinity of the transition piece.

With geometry A12, a large volume of fluid can be pumped into the premixing chamber. Due to the narrowing of the holes in the direction of the premixing chamber, an injector effect is simultaneously achieved, which leads to high turbulences in the premixing chamber. The geometry B12, however, leads to a lower penetration depth. In general, if the inflow through the inlets 25 into the premixing chambers 2 is large, a large penetration into the premixing chamber should be achieved with the liquid supplied via the inlet 8 into the dispersing chamber and from there into the premixing chamber 2.

In FIG. 7 is a section through a transition piece in a schematic representation of the fluid movement during operation of the rotor-stator system shown. It can be seen the webs 39 of the transition piece, which is arranged at the transition between the premixing chamber 2 and the dispersing chamber, which consists between the stator 1 and the rotor 4.

The rotor 4 carries rotor teeth 5. Rotate the Rotozähne 5 under the transition piece 3 away, arise areas with an overpressure in front of the rotor tooth, so that liquid is conveyed from the dispersing through the channels 31 in the premixing chamber 2. While the liquid is conveyed along the rotor tooth in the direction of the transition piece or the premixing chamber, the passage of the rotor tooth, whose geometry is described in more detail below, can lead to the formation of jet streams and negative pressures. "Jet stream" refers to the meteorological term "jet-oriented flow" in which the flow velocity is significantly higher than in the vicinity of the jet stream.

In the FIG. 7 The schematic representation illustrated illustrates a simplified model concept, which does not claim to fully reflect the actual prevailing flow conditions.

In FIG. 8 a stator is shown in external view. The stator head 11 has an inlet bore 25, which allows the inlet to a premixing chamber 2 inside the stator. The stator head 11 is provided with a ring gear 123. The stator has a quick release 109, with which it to the container 101 (see FIG. FIG. 1 ) can be mounted. To the bore 25 may be an inlet pipe with valve, as in FIG. 1 represented, mounted. The stator has stator teeth, which run parallel to its longitudinal axis (vertical in the picture).

In FIG. 9 a stator core 12 of a stator with two sprockets is shown. Parallel to the longitudinal axis 14 of the stator fuselage run an inner ring gear 124 and outer sprocket 123. The teeth of the inner sprocket are about half as long as the teeth of the outer sprocket. The Statorrumpf has through holes through which it can be fixed by means of screws on the stator head.

In FIG. 10 An embodiment of the rotor status system according to the invention is shown. Above, the stator 1 is shown. The stator 1 has an inner and an outer toothed rim 123, 124. In the center region of the stator 1 is the inlet 15, through which, following the inlet 8 fluid from the master container 101 (see FIG. 1 ) can get into the dispersing area. Inside the stator 1, two premixing chambers 2 are arranged, at the transition 27 to the dispersion region transition pieces 3 are arranged with slots.

The stator 1, together with a rotor, forms a rotor-stator system according to the invention. As seen in the radial direction from the axis of rotation of the rotor, there is a gap between the rotor and the stator. The width of this gap is about 0.1 mm to about 1.5 mm. The gap width is adapted to the dispersion task.

If premixing chambers are provided both above the inner and outer sprockets of the rotor in order to externally add relatively high viscosity media and relatively low viscosity media in a single pass through the rotor-stator system, the gap width can be, for example, 0 , 35 mm, when added via pre-mixing chambers equidistant from the center axis, should be increased to 0.8 mm to obtain larger droplets.

Such a rotor of the rotor-stator system according to the invention, for example, as in FIG. 10 be designed below. This rotor 4 has a carrier plate 42 which carries an inner ring gear 424 and an outer ring gear 423. The teeth 5 have a concave form in plan view. It should be emphasized that the operation of the premixing chambers according to the invention is not limited to such a specific tooth geometry. Rather, the invention of a stator with internal premixing chambers can work with all tooth geometries or rotors which can build up a pressure in the direction of the premixing chamber from the dispersing chamber.

For comparison is FIG. 11 a rotor and a stator of a conventional rotor-stator system shown. Based on the invention, one can clearly see the differences in the design of the stator (on the right in FIG FIG. 11 ), which has no premixing chambers, as well as this rotor (left in FIG. 11 ), which has substantially more teeth, but which do not form sprockets and have different orientations to a radial from the axis of rotation of the rotor.

In the FIGS. 12 to 16 For various embodiments, the geometry of the rotor and in particular of the rotor teeth 5 is shown. The rotor 4 has a carrier disk 42 with a through hole coaxial with the axis of rotation 14 of the rotor. This through-hole serves to connect the rotor 4 to the drive shaft 115 for connection to the motor 116 (see FIG FIG. 1 ). The carrier disk 42 of the rotor 4 carries rotor teeth 5.

The external dimensions of the rotor and the height of the rotor teeth are selected in accordance with the rated power of the motor and thus of the rotor-stator system. The following table gives an exemplary overview of suitable combinations of the mentioned parameters. Outer diameter of the rotor in mm Rated power of the motor in kW Height of the rotor teeth in mm 50 2.2 8 to 10 75 5.5 10 to 12 100 11 12 to 18 150 22 18 to 24 175 30 to 45 24 to 32 285 55 to 75 24 to 40

Rotor-stator systems can be designed in one or more stages, as an example, a two-stage dispersing machine is shown here. It is a rotor-stator system with two sprockets of the rotor, an inner and an outer sprocket. The inner sprocket 424 has 4 rotor teeth. The outer sprocket 423 has eight rotor teeth. This ratio of 1 to 2 is chosen to ensure continuous internal pressure build-up in the machine. Another ratio, for example 1 to 3, brings such success.

The rotor teeth of the inner ring gear 424 have a width, measured in the radial direction from the rotation axis 14, which is approximately twice as large as the width of the rotor teeth of the outer ring gear 423 (see FIG. 12 top left).

A rotor tooth 5 has an inner side 51 facing the center axis 14 of the rotor 4 and an outer side 52 facing the outer edge of the carrier disk 42. In the direction of rotation of the rotor 4 in front is the front 53 of the rotor. In the direction of rotation of the rotor in the back is the back 54 of the rotor tooth. On the side facing away from the support plate 42 side, a rotor tooth is closed by the top 55 of the rotor tooth. The rotor teeth of the inner ring gear have seen a distance d ₁ from the center axis 14 of the rotor, which is smaller than the distance d _{2 of} the rotor teeth of the outer ring gear 423th

The front side 53 of a rotor tooth 5 is inclined relative to a radially extending from the axis of rotation 14 of the rotor 4 from the reference line 57 by an angle α ₆ relative to the direction of rotation of the rotor to the rear. In the exemplary embodiments shown, the rear side 54 of the rotor tooth is oriented essentially perpendicular to the carrier disk 42. However, the back of the rotor tooth can also have any other orientations. In operation of the rotor-stator system causes the inclination of the front of the rotor tooth by the angle α _6, a radial acceleration of the product in the treatment in the dispersion.

The front side 53 has a region 56, which is inclined relative to the perpendicular to the support plate 42 of the rotor 4 by an angle α ₄ to the rear. Due to the offset of the region 56 of the front side 53 by the angle α ₄ , a pressure component is imparted to the fluid in the dispersion chamber in the operating state of the rotor-stator system, which promotes the fluid in the direction of the stator head and in particular into the premixing chambers. In addition, the degree of turbulence of the flow is increased by the inclination of the region 56 of the front side of the rotor tooth through the angle α ₄ when passing through the stator teeth, which are essentially parallelepipedal and parallel to the axis of rotation 14.

While preferably the region 56 of the front side, which is inclined backwards by the angle α ₄ , is arranged in the lower region of the front side, that is to say the carrier disk 42, the rotor tooth 5 is arranged in the Figures 12 . 13 . 14 and 16 shown embodiments on its front side 53 on an upper portion 58 which is inclined with respect to a parallel to the main extension direction of the support plate 42 extending reference line 45 downward in the direction of rotation of the rotor 4 by an angle α ₅ . Due to the inclination of this upper region 58 of the front side 53 of the rotor tooth 5 by the angle α ₅ , the pressure component of the fluid, which is produced by the inclination α _{4 of} the region 56 of the front side of the rotor tooth 5 and away from the carrier disk 42, is increased. This contributes to the formation of jet streams at the corresponding regions in the vicinity of the region 58 of the rotor tooth 5 in the dispersion space during operation of the rotor-stator system.

According to the model presentation, the jet stream is particularly pronounced where the rotor teeth pass through regions of the stator head which do not pass into a premixing chamber. Due to the multi-part design of the front side 53 with the inclined by the angle α ₄ and α ₅ areas 56 and 58, an additional dispersing edge is provided on the rotor tooth. Due to the additional dispersing edge, the dispersion efficiency compared to a rotor tooth with only one edge on the Transition of the front in the top of the rotor tooth increases.

Between the upper side facing away from the support side 42 of the upper rear side 54 of the rotor tooth 5 and the upper boundary of the upper portion 58 of the front 53 of the rotor tooth extends the top 55 of the rotor tooth. According to the in the Figures 12 . 13 . 15 and 16 In the exemplary embodiments shown, the upper side 55 is removed from its front beginning in the direction of rotation of the rotor at the upper end of the region 58 towards its rear end at the transition to the rear side 54 of the rotor tooth. In the detail drawing top right in FIG. 12 a correspondingly curved extending contour of the top 55 of the rotor tooth 5 is shown, as it can be prepared for example by milling. The depth of the cutout considered with respect to line 45 is a measure of how much fluid can be drawn from the premixing chamber into the dispersing space as the rotor tooth 5 passes the transition from the premixing chamber into the dispersing space during operation of the rotor-stator system , Instead of the longitudinal cut arcuate cutout (see FIG. 12 ), for example, a simple bevel (see Figures 13 . 15 and 16 ) to get voted.

With regard to the design of the rotor tooth, there are various possibilities for influencing the flow conditions in the dispersion space during operation of the rotor-stator system by the shaping, and in particular the preconditions for an increased degree of turbulence in comparison to conventional designs (see FIG. 11 ) to accomplish. All in the FIGS. 12 to 17 Examples shown meet these requirements and offer by the recognizable in longitudinal section bevels on Rotor tooth at least one additional dispersing edge compared to substantially cuboid rotor teeth by the rotor teeth have a serrated surface.

The rotor teeth are designed by the construction described above so that both a radial conveying direction is formed by the dispersing, which is in particular realized by the angle α ₆ , as well as an axial pressure component on the stator out, so here from the dispersing into the premixing chamber, which is realized in particular by the angle α ₄ . If a rotor tooth passes the transition between the premixing chamber and the dispersion chamber, an overpressure and a negative pressure are generated very rapidly, for example in the region of milliseconds, at each rotor tooth, which is passed on to the fluid in the premixing chamber, as a result of which strong turbulences of the two Phases emerge into each other. By lowering the top surface 55 of the rotor tooth with respect to the reference line 45, a negative pressure is generated so that fluid is simultaneously drawn from the premixing chamber into the dispersing space.

In FIG. 7 the model concept for the fluid movement described above is shown schematically. The comminution effect of the rotor-stator system can be adjusted by the choice of geometry, in particular by the choice of the angle α _{4 of} the rotor tooth, in coordination with the peripheral speed of the rotor tooth and the throughput through the dispersing machine. The angle α ₄ and peripheral speed of the rotor teeth mainly determine the volume of fluid, which is conveyed from the dispersion into the premixing chambers. The larger α ₄ at the same Circumferential speed is, the larger this volume.

The volume of the second component or further components metered in via the premixing chambers depends mainly on the selected settings of the pumps in the inlet 25. For example, a combination of these pumps with a frequency converter, the desired pump setting can be specified. By positioning a flow meter in the inlet 25, the volume flow supplied to the dispersion space can be displayed via the inlet 25.

In FIG. 17 Further variants for the geometry of the rotor tooth 5 are shown. The rotor tooth 5 shown in FIG. 17 a has a front side with a lower region running vertically with respect to the main expansion direction of the carrier disk 42 and with an upper region inclined towards the rear with respect to the direction of rotation of the rotor with the rotor tooth 5. The upper side of the rotor tooth runs parallel to the main expansion direction of the carrier disk. In Figure 17b, the top surface 55 of the rotor tooth 5 has been chamfered as compared to the design shown in Figure 17a. The embodiment of the rotor tooth illustrated in FIG. 17 c has an inclined front side 53, an upper side 55 running parallel to the main extension direction of the carrier disk, and a rear side 54 which is inclined towards the front side 53. By such an inclination of the back 54, the collection effect, which is described above for a lowered upper side 55 of the rotor tooth, can be enhanced.

In FIG. 18 is a model concept for the effect of different designs of rotor teeth on the flow conditions in the vicinity of the operation of the Rotor-stator system shown. In the illustration of the stator 1, an area was selected which has no premixing chambers in order to draw attention to the flow conditions in the vicinity of the rotor tooth.

Figure 14a shows a rotor tooth with a flat cutout on the top side. Such a design is typically used for small to moderate amounts of addition to the components of the dispersion to be made via the inlet 25 via the premixing chamber. Low to medium addition levels correspond to a proportion of the respective component in the finished dispersion of about 5 vol .-% to about 30 vol .-%.

The rotor tooth 5 shown in FIG. 18a also shows a smooth transition from the carrier disk 42 of the rotor to the rotor tooth in the lower region of its front side 53. By such a flowing design at the origin of the front side of the rotor tooth from the carrier disk, dead zones for the fluid in the dispersion chamber are reduced. FIG. 18b shows a rotor tooth according to a further embodiment with a very deep indentation of the upper side 55 of the rotor tooth in comparison to the rotor tooth shown in FIG. 18a. Such a design may be used for medium to large addition levels of the components of the dispersion fed via the inlet 25 through the premixing chambers into the dispersion space. Average to large addition levels of the corresponding component mean a proportion of this component in the range between more than about 30% by volume and about 80% by volume of the dispersion to be prepared.

With the in FIG. 18 from the stator 1 to the rotor extending vertical dashed lines are the stator teeth indicated. Where a rotor tooth passes such a straight stator tooth, microturbulences, which occur in FIG. 18 with turbulence I are designated. Compared to the jet stream flows designated turbulence II, the areas in which microturbulences are generated have many high-energy small vortices in the fluid of the dispersion space.

FIG. 19 illustrates a model concept of making an emulsion in a rotor-stator system. On the left is the area marked 2, which shows an emulsion when passing through the dispersing chamber 7. Subsequent to the treatment in the dispersion space, further stabilization of the droplets of the emulsion can take place when the outlet 9 flows through.

After the first contact of the two phases of the emulsion in the premixing chamber (beginning at the far left in FIG. 19 ), the two phases are mixed and droplets of the disperse phase are formed in the continuous phase. In the illustrated example of the emulsion, the disperse phase is a lipophilic phase and the continuous phase is an aqueous phase. Emulsifier molecules are dissolved in the continuous phase. These are presented in the continuous phase in an amount such that at least at the beginning of the process partially form micelles of emulsifier molecules.

As soon as an interface between the lipophilic and aqueous fluids is provided by the contact of the disperse phase with the continuous phase, the emulsifier molecules begin to accumulate at this interface. When passing through the premixing the first large drops of disperse phase further crushed. Emulsifier molecules increasingly accumulate at the interface between the disperse and continuous phases. The comminution of the droplets and the stabilization of the interface by emulsifier molecules continue as they pass through the dispersion chamber 7. Also during the passage of the dispersion leaving the dispersing chamber 7 through the outlet 9, the process of stabilizing the droplets formed by emulsifier molecules can be continued.

To further reduce the size of the initially large droplets of the disperse phase, in particular when passing through the premixing chamber, a more detailed model concept was also developed. Accordingly, the deformatin and the onset of the drops are at least partially involving baker's transformation (see, for example Joseph Maria Henri Janssen: Dynamics of Liquid-Liquid Mixing, Chapter 2, Thesis 1993, University of Eindhoven, NL, ISBN 90-386-0402-5 ).

The model for the deformation of fluid elements by the Baker transformation is in FIG. 20 shown schematically. The baker's transformation was named after the dough kneading process. A dough is pulled twice the length and then folded so that the two ends are on top of each other. This procedure is repeated until good mixing has occurred. Two particles, which were originally close together, are far apart after a short time.

The representation for the model concept for the deformation of fluid elements starts from a considered fluid element in surrounding medium (Figure 20A ). This fluid element is stretched by stretching ( Figure 20B ), in which its height and width decreases accordingly. Then the fluid element is folded ( Figure 20C ). After folding, stretching and wrinkles continue ( FIGS. 20D to 20F ), wherein the fluid of the considered element and the surrounding medium are mixed together. Through this baker's transformation, stretching and folding through the alternating sequence leads to an exponential progress of mixing.

In FIG. 21 the mixing of the continuous and the disperse phase to form droplets in the premixing chamber is again illustrated, in comparison to the illustration in FIG FIG. 19 taking into account the baker's transformation. This causes streaks to bubbles of the droplets forming disperse phase, which are then broken when passing through the first and second ring gear of the rotor 5 in the dispersing 7 to smaller droplets. The peripheral speed, and thus in particular the shear rate, increases continuously as the fluid from the premixing chamber passes over the inner rotor rim and the outer rotor rim until the maximum is reached, thereby promoting the controlled dripping of droplets. Then follows a turbulent stabilization in the outlet channel and the circulation line.

This intensive mixing of the disperse and continuous phases in the premixing chamber is promoted by cooperation with the rotors when the outer phase is forced through the axial component of the flow direction at the rotor teeth into the premixing chamber in the manner of an injector. The resulting jet cuts the disperse phase to streaks, which are folded by the sudden reversal of direction (negative pressure). The principle can be understood as the kneading of a pizza dough, wherein the outer phase is embedded in the streak. The key to pulling and folding the fluid elements lies in the sudden alternation of positive and negative pressure at each opening of the premixing chamber made possible by the invention.

One purpose of the premixing chamber is to minimize irregular droplet formation prior to high energy dispersion in the dispersing space. A fine, homogeneous crude emulsion or raw dispersion prevents over-concentration of droplets (clustering) and guarantees a fine, homogeneous emulsion or dispersion after the high-energy zone, especially in one pass (inline). In contrast, an over-concentration of droplets involves the risk of a phase reversal.

Another purpose of the premixing chamber is to achieve the dispersing operation in one pass without the emulsifier settling completely around the droplets before or during dispersing. Thus, a discontinuous breakup of the droplets is achieved while the emulsifier film is not yet complete. This results in higher droplet breakup efficiency and smaller droplets, and is particularly important in fabric systems with high viscosity differences between disperse and continuous phases.

The premixing chamber described above can be used not only in stators for rotor-stator systems of dispersing machines, but also in pumps, agitators and similar apparatus in which a plurality of at least partially liquid components are to be mixed together. In FIG. 22 is a schematic sketch a premixing chamber, which can be welded into a pump housing. The premixing chamber is made, for example, from a solid stainless steel piece and corresponds in geometry to the example in relation to FIG. 2 given description.

The premix chamber is mounted on the pressure generating side of the apparatus. Due to the overpressure of the moving part, that is, for example, the rotor or the stirrer or the moving pump component, the pumped component of the dispersion is forced into the premixing chamber. The change of overpressure and negative pressure as a result of the movement of the dispersing element or the moving pump part, presses or sucks the increasingly homogenized premix from the premixing chamber.

In the case of very high-viscosity products, after passing through a pump equipped with a premixing chamber, a post-mixing can be carried out. For this example, static mixers or Rührwerktanks and similar arrangements can be used.

The supply of components into the premixing chambers is effected by feed pipes corresponding to the inlets 25 in FIG FIG. 1 , By pumps such as positive displacement pumps, the raw materials are fed into the premixing chambers.

In FIG. 23 is a front view of a pump equipped with a premixing pump shown in the pump housing. The pump has an inlet 8 for a fluid and a further inlet 81 for a further fluid, by which this is supplied into the premixing chamber 2. Through an outlet 9, the mixture of fluids is withdrawn from the pump. The premixing chamber is shown in FIG FIG. 23 to the left of the pump outlet 9. The Direction of rotation of the moving pump component is counterclockwise in the plane of the drawing. The pump wheels can be designed as standard pump wheels such as those of centrifugal pumps and take over the function of the rotor in the above description of the rotor-stator systems.

example 1

A dispersing machine with a rotor and a stator has a rated power of 30 kW. The rotor has an outer diameter of about 175 mm. The stator has four premix chambers, which are arranged above the inner of the two rotor crowns of the rotor. The premix chambers each have a length of about 10 cm, measured along the main extension direction of the premix chambers. Perpendicular to the main extension direction, they are about 1.2 cm wide. They have an average depth of about 2 cm, measured from the transition region of the premixing chamber into the dispersing chamber, into the interior of the stator. Each chamber has a volume of about 24 cm ³ _.

It is believed that this volume is washed out by any rotor tooth passing through the premix chamber during operation of the rotor-stator system. This means a throughput of 288,000 cm ³ / min or 0.288 m ³ / min or 17.3 m ³ / h for each pre-mixing chamber at 3000 revolutions / minute and four teeth on the inner rotor ring.

At a concentration ratio of the fed via the premixing chambers (in an emulsion, for example, internal) phase to that in the dispersion Thus, 7 m ³ / h of internal phase per premixing chamber can be processed in this way (40% by volume on the example of an emulsion). This results in four premix chambers a possible volume to be introduced of 28 m ³ in each hour. Thus, the dispersing machine is far superior to conventional apparatus.

Example 2

For the dilution of substances with water, wherein a transition state is passed, in which a dispersion-like system of the substance and water is present, there are further advantages. An example of such substances are detergent-active substances (WAS) such as AE3S 70%, LES 70% and similar substances. These raw materials must be diluted in one pass through the machine used for dilution to a volume fraction of less than 30% in water, otherwise a hexagonal phase can occur, which may have a viscosity which is higher by a factor of 10 than the viscosity of the original raw material.

Conventional machines often have the problem that the substance to be diluted can not be sufficiently brought into contact with water, so that local over-concentration occurs in areas where the two phases are brought together. These local excess concentrations lead to the dilution of washing-active substances with water to so-called fish eyes (hexagonal phase), which are difficult to re-open in the further course. The capacities of conventional dispersing machines for diluting washing-active substances are thus extremely low. By the premixing chamber, however, can the particular requirements of the dilution of detergent substances with water are taken into account and the desired capacity can be flexibly adapted.

Highly concentrated washing-active substances with a content of 70% by volume of the substance dissolved in water (WHAT 70%) such as AE3S, LES or similar, are delivered in a standard container of about 23,000 kg. The unloading time is about 60 to 90 minutes and is limited by the pipe connections of the containers and the high viscosity of the product. The WAS is stored in storage tanks and then continuously diluted to a concentration of 25% by volume of wash-active substance in water. For production, the detergent substance diluted in this way is stored in other storage tanks.

Traditional continuous dilution systems are expensive. To keep the costs within limits, the size is adjusted to the needs. When changing the applications, the user is thus limited by the existing dilution system.

By contrast, a system with premixing chambers is able to dilute the quantity of washing-active substance to be supplied for dilution directly from the container in which the substance is delivered, in a continuous process. If required, a batch process can also be used, for which purpose a correspondingly smaller machine with premixing chambers is used. For example, with a dispersing machine, 455 kg / min of water may be supplied to the stator under the control of a flow meter, so that this volume of water passes into the dispersing space.

Through the feeds to Vormischkammern 255 kg / min detergent substance are pumped. In one run, the detergent-active substance is then diluted to a volume fraction of 25%. For this application, the commercially available dispersing machine of the applicant LEXA-MIX LM30, with a nominal power of 30 kW can be used. The processing of such high amounts of raw material, both in continuous and in batch process is not possible with conventional dispersing machines, which allow a throughput of 25-80 kg / min of substance to be dispersed.

Furthermore, there is the advantage of being able to significantly reduce the investment costs. The acquisition cost of a typical continuous plant for diluting washing-active substances in 2008 will cost about 180,000, - EUR. The mentioned LEXA-MIX dispersing machine, on the other hand, has a purchase cost of only 50.000, - EUR in the year 2008.

Example 3

Another application is the continuous production of emulsions with a large internal phase fraction, so-called HIP emulsions (high internal phase emulsion), such as mayonnaise. In the example considered, 10,000 kg / h of mayonnaise with a water phase of 20% by volume and an oil phase of 80% by volume are produced. The oil phase forms the disperse phase of an oil-in-water emulsion. Water phase and oil phase are the machine in the correct proportion controlled via flow meter via the feeds to the premixing chamber (oil phase) and fed through the stator in the dispersion (water phase).

If a large amount of oil is to be incorporated into a relatively small amount of water, a large interface between the two phases must be created. The continuous production of such a large interface combined with a desired homogeneous distribution of the oil droplets in the water phase is made possible by the pre-mixing chamber dispersing machine. If necessary, a second dispersing machine, which is connected in series with a first, can be used to continuously introduce further additives, such as lemon juice, into the emulsion prepared in the first dispersing machine.

In particular, the dispersing machine can be designed such that it circulates a larger volume, for example three to five times the actual production volume, in a bypass in order to achieve optimum homogeneity of the product.

All piping of the dispersing machine can be made coolable. However, cooling is usually not necessary because heat generation is limited by the large throughputs and low residence times for most products.

Example 4

When introducing larger water droplets as drops with low viscosity in a much firmer make-up based on silicone, the droplets of the water phase should have a mean diameter of about 100 microns (microns), so that when applying the make-up the moisture Water phase is perceived as a feeling of freshness. However, the silicone base of the make-up means that with increasing shear, the make-up always receives a higher viscosity (shear-thickening). As a result, smaller and smaller droplets of water would be created as you spread your make-up. This is not wanted.

By using a dispersing machine with premixing chambers, at average peripheral speeds ranging from about 10 m / s to about 20 m / s, the silicone base material can be conveyed via a transition piece of the form B10 (cf. FIG. 6a ) are conveyed into the premixing chamber. The water phase supplied via the premixing chamber is distributed in droplet form in the silicone base mass and then gently dispersed. Uniform distribution and size of the water droplets in the matrix can be achieved by a suitable choice of the dispersing machine supplied volume flows of the speed of the rotor and shape of the transition piece already with one pass.

It will be apparent to those skilled in the art that the invention is not limited to the embodiments described above, but rather can be varied in many ways. In particular, the features of the individual embodiments can also be combined or replaced with each other.

LIST OF REFERENCE NUMBERS

1

stator

11

stator head

123

outer ring gear of the stator

124

inner ring gear of the stator

12

Statorrumpf

14

Longitudinal axis of the stator = axis of rotation of the rotor = center axis of the rotor

15

Inlet, feed from a feed tank into the dispersion area

17

Dispersion area of the stator

2

premix

25

Inlet, inlet into the premixing chamber

27

Transition of the premixing chamber to the dispersion area

28

Circumferential line of the transition of the premixing chamber to the dispersion area

3

Transition piece, ejector, injector

31

Openings, slots, holes in the transition piece

32

Main expansion direction of the transition piece

33

hole axis

34

Vertical to the transition piece

35

Lateral surface of the opening in the transition piece

36

first portion of the lateral surface

37

further subregion of the lateral surface

38

section

39

web

4

rotor

423

outer ring gear of the rotor

424

inner sprocket of the rotor

42

Carrier disk of the rotor

45

Parallel to the main expansion surface of the carrier disk

5

rotor tooth

51

Inside of the rotor tooth

52

Outside of the rotor tooth

53

Front of the rotor tooth

54

Rear of the rotor tooth

55

Top of rotor tooth

56

Area of the front, which is inclined backwards

57

reference line

58

upper area of the front

59

lower area of the front

6

Rotor-stator system

7

dispersion chamber

8th

Inlet for a fluid in a dispersing machine or a pump

81

Inlet for another fluid in a dispersing machine or a pump

82

Inlet for another fluid in a dispersing machine or a pump

9

Outlet of a fluid from a dispersing machine or a pump

10

dispersing

101

first storage tank

102

second storage tank

109

Quick release for changing the stator head

112

Annular channel, gap between the extreme toothed ring of the stator and the housing of the dispersing machine

113

casing

115

Drive shaft for the rotor

116

engine

117

Seal, mechanical seal

118

Seal, O-ring, static seal

Claims (9)

1. Rotor-stator system (6) for the production and/or treatment of dispersions having a stator (1)
   with a dispersion zone (17), which, with a rotor (4) corresponding with the stator (1) defines a dispersion compartment (7) of the rotor-stator systems (6), and
   with an inlet (15) for feeding a first component of a dispersion into the dispersion zone (17)
   wherein the inside of the stator accommodates at least one premixing chamber (2) outside the dispersion zone (17), which opens into the dispersion zone (17),
   the stator (1) having at lease one inlet (25) for feeding another component of the dispersion from outside the stator (1) into the premixing chamber (2), and
   the stator (1) being designed so that during operation of the stator, components of the dispersion enter the premixing chamber (2) from the dispersion zone (17) and from the inlet (25), are mixed in said premixing chamber (2), and exit from the premixing chamber (2) into the dispersion zone (17)
   characterized in that
   a transition piece (3) is arranged between the premixing chamber (2) and the dispersion zone (17) which is designed like a perforated plate, and provides one or a plurality of circular and/or polygonous openings, and/or a slot or a plurality of slots as holes (31).
2. Rotor-stator-system (6) according to claim 1,
   characterized in that
   the stator (1) has at least two premixing chambers (2), each providing one inlet (25) for feeding a component of the dispersion from outside the stator (1) into the relevant premixing chamber (2),
   and/or that
   the premixing chamber (2) curves into the stator (1) from the transition to the dispersion zone (17),
   and/or that
   the premixing chamber (2) has the shape of a strip-like section of a circle segment at the transition to the dispersion zone (17), this section, in particular, having a continuously curved circumferential line (28),
   and/or that
   the transition of the premixing chamber (2) to the dispersion zone (17) is positioned at such a radial distance from the longitudinal axis (14) of the stator, which is identical with the axis of rotation of the rotor (4) corresponding with the stator (1), that the premixing chamber (2) is positioned above a dispersion tool, in particular a tooth ring (423, 424) of the rotor, when the stator (1) is combined with the corresponding rotor (4) to form the rotor-stator system (6),
   and/or that
   the transition of the premixing chamber (2) to the dispersion zone (17) is positioned at such a radial distance from the longitudinal axis (14) of the stator (1) which is identical with the axis of rotation of the rotor (4) corresponding with the stator (1), that the premixing chamber (2) is positioned at least above the inner dispersion tool, in particular the inner tooth ring (424), of a rotor with more than one dispersion tools, when the stator (1) is combined with the corresponding rotor (4) to form the rotor-stator system (6).
3. Rotor-stator-system (6) according to claim 1 or 2,
   characterized in that
   the stator (1) has at least two premixing chambers (2) that are positioned at different radial distances from the longitudinal axis (14) of the stator.
4. Rotor-stator-system (6) according to any of the claims 1 to 3,
   characterized in that
   the transition piece (3) takes up part of, or the complete area of the transition between the premixing chamber (2) and the dispersion zone (17),
   and/or that
   the transition piece (3) has the shape of a strip-like section of a circle segment.
5. Rotor-stator-system (6) according to any of the preceding claims, characterized in that
   the transition piece (3) comprises a slot or a plurality of slots as holes (31) with
   several slots being essentially arranged at right angles with the main direction of expansion (32) of the transition piece (3),
   or that
   the transition piece (3) comprises several slots as holes (31) with several slots preferably being essentially arranged at right angles with the main direction of expansion (32) of the transition piece (3), and with the holes (31) passing through the transition piece (3) are arranged along a hole axis (33), which together with the line perpendicular to the transition piece (3) forms and angle,
   in particular an angle within the range between about 10° and about 80°, preferably within the range between about 30° and about 60°, and especially preferably an angle of about 45°,
   and/or that
   the transition piece (3) comprises several slots as holes (31) with several slots preferably being essentially arranged at right angles with the main direction of expansion (32) of the transition piece (3),
   and with the holes (31) passing through the transition piece (3) are arranged along a hole axis (33), which together with the line perpendicular to the transition piece (3) forms and angle,
   in particular an angle within the range between about 10° and about 80°, preferably within the range between about 30° and about 60°, and especially preferably an angle of about 45°,
   and/or that
   the holes (31) through the transition piece (3) are delimited by a lateral area (35) with a first partial area (36) and at least one additional partial area (37),
   at least one partial area (36, 37) running along an intersecting plane which together with the line perpendicular to the transition piece (3) forms an angle,
   in particular an angle within the range between about 10° and about 80°, preferably within the range between about 30° and about 60°, and especially preferably an angle of about 45°,
   and/or that
   at least one premixing chamber (2) is designed in the stator (1) in particular in the stator head (11), such that a transition piece (3) can be fitted to the stator head so that it delimits said cavity.
6. Rotor-stator-system according to one of the claims 1 to 5, characterized in that
   the stator (1) is of the two-part type and comprises a stator head (11) and a stator body (12), at least one premixing chamber (2) being accommodated in the stator head (11), and
   the stator body (12) comprising a dispersion tool of the stator, in particular at least one tooth ring (123, 124)
   and/or
   several stator heads (11), which differ in the number and/or geometry of the premixing chambers (2), can be mounted on a stator body (12) in order to form a stator (1) with replaceable stator head.
7. Method for the production and/or treatment of dispersions, using a rotor-stator system (6) according to any of the claims 1 to 6, with the following steps

   a) provision of a first phase of the dispersion in a first receiving tank (101), which communicates with the dispersion compartment (7), and
   provision of at least one second phase of the dispersion in at least one second receiving tank (102), which communicates with a premixing chamber (2) wherein a translation piece (3) is arranged between the premixing chamber (2) and the dispersion zone (17) which is designed like a perforated plate, and provides one or a plurality of circular and/or polygonous openings, and/or a slot or a plurality of slots as holes (31),

   b) feeding the first phase of the dispersion into the dispersion compartment (7),

   c) feeding the second phase of the dispersion into the premixing chamber (2),

   d) driving the rotor (4),

   so that, with the rotor-stator system (6) in operation,
   the first phase passes the dispersion compartment (7) and enters the premixing chamber (2), thus getting into contact with the second phase, and thus forming a mixture and/or a dispersion from the first and the second phase, and
   the second phase and/or the mixture formed from the first and the second phase and/or the dispersion formed in the premixing chamber (2) from the first and the second phase, is conveyed through the premixing chamber into the dispersion compartment (7).
8. Method according to claim 7,
   characterized in that
   a stator (1) is used with at least one additional premixing chamber (2), and
   in step a) at least one additional phase of the dispersion is made available in at least one additional receiving tank, which communicates with the additional premixing chamber (2),
   the additional phase of the dispersion being fed, in step c) into the additional premixing chamber (2) of the rotor-stator system (6),
   so that, with the rotor-stator system in operation,
   the first phase passes the dispersion compartment (7) and enters the premixing chambers (2), thus getting into contact with the second phase or additional phase in the respective premixing chamber (2), and thus forming a mixture and/or a dispersion from the phases, and
   the second phase or at least one additional phase and/or the mixture and/or the dispersion formed in a premixing chamber (2) from at least two phases is conveyed through the respective premixing chamber (2) into the dispersion compartment (7).
9. Method according to one of the claims 7 or 8,
   characterized in that
   steps b), c) and d) are performed simultaneously,
   and/or that
   the process is performed as a continuous process,
   and/or
   in which the first phase added in step b) will form the disperse phase of the dispersion and the second phase added in step c) will form the continuous phase or an element of the continuous phase of the dispersion, and
   phase inversion occurs in the production of the dispersion and/or that
   the retention time in a premixing chamber (2) is within a range of between about 0.005 seconds and about 0.02 seconds.

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