EP2305370B1 - Homogeniser and homogenising device with such a homogeniser - Google Patents

Abstract

The homogenizer (1) has a shaft (12) displaced in rotation via a controllable drive. A stator (17) co-acts with a rotor (16). A shearing gap is formed between the rotor and the stator. The stator is axially displaced in reference to the rotor between a position, in which an axial section of the stator is arranged radially adjacent to the rotor under formation of the shearing gap, and another position so that no shearing gap exists between the rotor and the stator. The stator is arranged adjacent to the rotor in an axial direction in the latter position.

Description

The invention relates to a homogenizer for the homogenization or dispersion of flowable materials, with a rotatably mounted at least one rotor, and rotatable by means of a, in particular controllable, drive rotatable shaft and with a rotor cooperating with the stator, wherein between the rotor and the stator at least one shear gap is formed. The invention further relates to a homogenizer for homogenizing or dispersing flowable materials, with a particular equipped with a return container with at least one branching off of the container and leading into an inlet of a homogenizer of the aforementioned type branch line.

Such homogenizers are widely used for the homogenization or dispersion of flowable substances, such as liquid to more or less viscous substances or mixtures of substances, for example emulsions, dispersions, etc., for example in the chemical, pharmaceutical, cosmetic and food industries. It will be the homogenizers often operated together with a stirred tank, wherein the homogenizer in a outgoing from the container and optionally in this recirculating line, preferably at a level in the region of the lowest point of the container or below it, may be arranged, so that the homogenizer in addition to the agitator of the container contributes to a proper homogenization or dispersion of the product. The homogenizing effect is based primarily on the entry of shear forces on the flowable substances by rotation of the rotor, which cooperates with the counterpart stationary stator. The rotor may have one or more rotor blades, for example, in each case one arranged on both sides of the stator rotor blade, each defining a shearing gap between itself and the stator. In comparison with other types of homogenizers, such as high-pressure or ultrasonic homogenizers, generic homogenizers offer the advantage of a simpler and more cost-effective design and, in particular, a lower-wear operation.

In order to be able to set the homogenizing effect or, more precisely, the shear forces introduced into the flowable substances, the rotational speed of the rotor with respect to the stationary stator can be controllable, the shear effect increasing with increasing rotational speed of the rotor. At the same time the conveying effect of the homogenizer increases with increasing speed of its rotor, so that the conveying effect is coupled directly to the shearing action of the homogenizer. This is usually due to the fact that due to the relative movement between the rotor and stator in the shear gap formed between the rotor and the stator, a speed-dependent negative pressure is generated, which is to be processed Suction product and push through the gap radially outward. Processing of substances sensitive to shear forces is thus only possible to a certain extent, since a negative pressure sufficient for conveying the product through the shear gap formed between the rotor and the stator can only be achieved at a certain speed, which in turn has a certain minimum effect on the product Shearing forces conditionally. The same applies to the dispersion of sensitive to mechanical action solid particles, which are to be dispersed eg in a liquid or viscous medium and thus run the risk of being crushed in the shear gap.

The EP 1 395 354 B1 and DE 296 08 712 U1 describe a homogenizer in which the shear gap formed between the rotor and the stator is variable by axial displacement of the rotor. If at high speed of the rotor and consequent high conveying and heavy action latter are reduced, it can be increased in this way, the gap formed between the rotor and stator. However, even at maximum gap width of the rotor / stator system, the materials to be processed are still exposed to a not inconsiderable shearing action, and solid particles which are sensitive to mechanical action can not be dispersed in this way.

Moreover, it is known to provide instead of or in addition to a stator another, separately driven rotor, so that the shearing action of the homogenizer can be adjusted by individually adjusting the speed of both rotors with opposite or in the same direction rotation. However, such homogenizers require one relatively high design effort with two separate drives including the associated bearings and seals, which is associated with a relatively high cost. In particular, a processing of very shear-sensitive substances and / or sensitive to mechanical action solid particles is not possible in this case, especially - as already mentioned - the conveying effect here depends directly on the shearing effect. The DE 200 02 920 U1 . EP 1 825 907 A1 and EP 1 125 625 A1 describe such a homogenizer, which in addition to the rotor comprises a further, individually rotationally driven element, which may be formed by a further rotor or by a conveyor. Other known from the prior Tecknik devices are in the documents DE 20/2006 008 820 U . EP-A-0620039 . DE 1024923 and EP 2004315 disclosed.

The invention has the object of providing a homogenizer of the type mentioned in a simple and cost-effective way to the effect that its shearing effect can be limited to a minimum extent with continuous promotion, to him also an application for the processing of both very shear-sensitive substances as well to develop mechanical action of sensitive solid particles.

According to the invention this object is achieved in a homogenizer of the type mentioned and in a homogenizer equipped with such a homogenizer of the type mentioned in that the stator with respect to the rotor between at least a first position, in which at least an axial portion of the stator below Forming the shear gap is arranged radially adjacent to the rotor, and a second position in which the stator is arranged in the axial direction adjacent to the rotor, so that between the rotor and stator no shear gap is present, is axially displaceable.

The inventive design makes it possible in a structurally simple manner that the shearing effect can be lowered by a constant, at least by the rotation of the rotor effected flow through the homogenizer on a comparison with the prior art unequal lesser level up to virtually zero by the flowable product is passed past the rotor displaced from the stator, the rotor / stator system is thus "bypassed". For this purpose, the stator is displaced into its second position in which it is arranged axially next to the rotor and consequently the shearing gap formed between it and the rotor in the radial direction is no longer present. The flowable substances are now only by the centrifugal forces caused by the rotor, possibly supported by a conveyor (see below), conveyed through the homogenizer through which no or at most very low shear forces in the product or in the - for example from a liquid or viscous matrix with herein einispergierten, against mechanical stress sensitive solid particles formed product mixture are registered, but nevertheless provided for a certain, very gentle mixing / homogenizing effect. If, on the other hand, stronger shear forces are to be introduced into the product, then the stator is displaced into its at least one first position, in which it is arranged at least partially radially next to the rotor and forms a shear gap between itself and the rotor. The homogenizer according to the invention can therefore be, on the one hand, in a "shear mode", which is usual for generic homogenizers, in which the stator is in the first position, on the other hand operate in a conventional generic homogenizers so far not possible, pure "pump mode" in which the stator is in the second position and the flowable product is conveyed through the stator only. In addition, of course - if desired - the speed of the rotor, preferably independently of the respective position of the stator, be variable in order to change the shearing and / or conveying action of the homogenizer can.

In order to reliably prevent product shearing in the stator located in the second position, it may be advantageous if the stator in the second position with a certain axial distance, for example of at least 1 mm, preferably of at least 2 mm, in particular of at least 5 mm, is arranged by the rotor. In addition, it may be expedient if the stator abuts in the second position against a stop arranged on the side facing away from the rotor of the stator, in order to provide a structurally very simple way for a fixed predetermined second position of the stator, in which he product shear reliably prevented.

In an advantageous embodiment, it may be provided that the stator is arranged in at least a first position substantially over its entire axial extent radially adjacent to the rotor, for a - as I said, optionally additionally variable by the rotational speed of the rotor - shear of the product and thus to ensure the highest possible efficiency of the homogenizer in the "shear mode".

While it is basically sufficient for achieving the function of the homogenizer according to the invention, when the stator is displaceable exclusively between a (single) first position and the second position with respect to the rotor, it can of course also be provided that the stator is connected between a plurality of first positions, in which the stator is arranged in each case at least with an axial portion radially adjacent to the rotor, with respect to the rotor is displaceable. In the latter case, the shearing action, which is always present in the various first positions of the stator, can be further varied by increasing or decreasing the shearing gap formed between the rotor and the stator.

As already indicated, it is favorable in terms of design, if the rotor axially fixed and the stator is displaced in the axial direction, in principle, the rotor axially fixed and the stator can be arranged axially displaceable contrast.

In an advantageous development of the homogenizer according to the invention, provision can be made for a conveying device to be arranged upstream of the rotor / stator system formed by the rotor and the stator. By means of such a conveyor, in particular in the "pumping mode" (ie with the stator located in the second position) even at very low speed of the rotor and consequently very small, thereby caused centrifugal forces on the flowable materials at a very gentle mixture / homogenization, a sufficient flow rate of the product through the homogenizer. If, in particular, as mentioned above, an axially fixed stator and a counterpart in the second position displaceable rotor provided is, such a conveyor can also serve entirely for the required in the "pumping mode" capacity.

A particularly preferred embodiment provides that the homogenizer according to the invention is a so-called "external homogenizer" in which the rotor / stator system and optionally the conveyor are accommodated in a separate housing in which the shaft carrying the rotor is mounted ,

In this case, the housing preferably has at least one inlet arranged upstream of the rotor / stator system, which inlet can be connected in particular to a branch line of a container, in particular equipped with an agitator. In addition, the housing preferably has at least one outlet arranged downstream of the rotor / stator system, which outlet can be connected in particular to a return line of the container, in particular equipped with an agitator. The homogenizer is in this way part of a circulation line from the (stirring) container of a homogenizer and into it, in order to ensure a very effective mixing / homogenization of the products either in the "shear mode" and / or in the "pumping mode". Alternatively, it is of course also conceivable that - if the homogenizer is connected as part of a homogenizer to the (stirring) container - the homogenized product through its outlet, for. is also supplied to further processing steps or a bottling, instead of recirculating it in the (stirring) container.

The terms "upstream" and "downstream" in this context always refer to the intended conveying direction of the flowable substances through the homogenizer, ie from its inlet, optionally via the conveyor and the rotor / stator system to its outlet. The preferably present conveying device can be arranged otherwise upstream or downstream of the rotor, wherein it is also possible in principle to provide both an upstream and downstream of the rotor arranged conveyor.

The outlet of the homogenizer is expediently arranged radially with respect to the shaft carrying the rotor and in the axial region of the rotor / stator system, so that the mixed / homogenized product after passing through the rotor / stator system or - in the second Positioning stator - the rotor leaves the housing of the homogenizer radially. In order to ensure the highest possible conveying effect, it may be advantageous in this case if the rotor / stator system extends radially into the region of the inner wall of the housing.

If the homogenizer is equipped with a conveying device, it may, for example, have at least one conveying element that can be rotated coaxially with the shaft of the rotor, which may be designed, for example, in the form of a screw element of a screw conveyor and expediently extends around at least a part of the circumference of its axis of rotation. In order to ensure a satisfactory conveying effect even with gentle operation of the homogenizer in the "pumping mode" at low speed of the conveyor when the stator is in the second position, the conveying element preferably extends into the region of the inner wall of the housing, so that the flowable material at least not to a significant extent between the conveyor element and the inner wall of the housing can flow past the conveyor element. Of course, between the free end of the conveying element and the inner wall of the housing, a small gap, for example, be formed with a width of at most about 2 mm or at most about 1 mm, to ensure a low-wear operation of the conveyor. In addition, it may be for the purpose of pressure build-up advantageous if the conveyor (eg at least one conveying element) is disposed on a narrowing of the inner side portion of the housing, wherein the term "narrowing" on the conveying direction of the flowable substances through the homogenizer refers.

According to a development of the homogenizer according to the invention, a mixing device may further be provided, the arrangement of which may be selected upstream or downstream thereof or also between the rotor / stator system and / or on the conveyor. In this case, it is possible, in particular, to ensure, during the gentle operation of the homogenizer in the "pumping mode" with the stator in the second position, an increased but nevertheless very low shear homogenization / dispersion of the flowable substances due to the homogenizing effect of the additional mixing device. In addition, the mixer can of course also in the conventional operation of the homogenizer in the "shear mode" additional homogenization / dispersion or - if the mixing device is arranged upstream of the rotor - cause some pre-homogenization. In any case, such a configuration opens the homogenizer a practically suitable for any flowable materials use, they are relatively insensitive or highly sensitive to shear forces or against mechanical stress.

The mixing device may preferably have at least one or in particular a plurality of mixing vanes which can be set into rotation coaxially with the axis of rotation of the rotor and which advantageously extend (only) around part of the circumference of its axis of rotation. In addition, a plurality of mixing vanes may preferably be arranged with radial and / or axial distance from each other, so that a uniform, gentle mixing or homogenization of the product over the entire cross-section of the homogenizer is possible. In addition, the mixing blade (s) of the mixing device can be arranged obliquely with respect to its axis of rotation, as a result of which the mixing or homogenizing effect can be improved and optionally an additional conveying effect can be induced; The mixing blades can have, for example, an approximately propeller-like shape. Further, the mixing blade (s) may be perforated to provide a further improved mixing or homogenizing effect thereby allowing a (small) flow of material through the mixing blades. However, the mixing device can of course also have any differently configured mixing elements as an alternative or in addition to such mixing blades. By way of example only, in this context, for example at least partially in the radial direction extending mixing rods are mentioned, which may for example be fixed to the axis of rotation of the mixing device and optionally with stationary stationary on the inner wall of the housing of the homogenizer with axial offset thereto arranged stationary, for example, also rod-shaped elements can cooperate ,

In order to provide a structurally very simple and cost-effective design, the rotor and the conveyor and / or the mixing device can be set in rotation, in particular by means of one and the same, preferably controllable, drive, for example, sit on one and the same shaft, which passes through the homogenizer in the axial direction. If desired, in the case of the presence of a conveyor, the rotor may be decoupled from the drive in order to be able to convey the product, if necessary, with rotor at rest completely free of shear induced by the rotor through the homogenizer. The same can apply to the mixing device, provided that e.g. it is desirable to promote the flowable materials with a stationary rotor and stationary mixing device only by means of the conveyor through the homogenizer to mix them slowly and gently or homogenize.

Alternatively, on the one hand, the rotor, on the other hand, the conveyor and possibly also the mixing device, in the latter case preferably the conveyor together with the mixing device, of course, be driven independently.

The rotor and the stator may be substantially in the form of a cylinder jacket having circumferentially distributed radial openings exposed therein, with the shear gap formed between the rotor and the stator in a first position. The rotor may, of course, comprise one or more rotor blades, such as two rotor blades, one of which is disposed radially inward and radially outward of the stator, so that in a first rotor Position of the stator two shear gaps are formed, wherein the individual rotor blades may in turn be driven together or separately from each other or may be individually or jointly decoupled from a respective or common drive. In any case, the radial openings of the rotor may preferably have a different shape and / or size than the openings of the stator.

While the stator can basically also be displaced manually relative to the rotor, an advantageous embodiment provides that an actuator is provided for displacing the stator with respect to the rotor. For this purpose, virtually any known, designed in particular in the form of linear actuators actuators into consideration, such as hydraulically, pneumatically or hydropneumatically actuated piston / cylinder units, mechanically or equally fluidly actuated push rods, racks, screw thread, etc. The actuator can in each case preferably with rotating Rotor be actuated.

In a further advantageous embodiment can be provided that the actuator is fixed to a cover of the housing of the homogenizer frontally closing, the cover with the actuator in particular from the housing of the homogenizer and removable against a provided with an end inlet opening for the task of an additional substance component lid can be interchangeable. The latter embodiment opens up a further application to the homogenizer according to the invention, namely the dispersing of a further substance component via the additional inlet into the flowable substance, wherein the additional substance component is in particular powdery or particulate can be. As a result of the negative pressure caused by the rotating rotor, the additional substance component can be easily sucked in and dispersed into the substance, whereby lumping is avoided even in the case of very fine particulate matter components, because the substance components in the region of the homogenizer with very high turbulence, ie in the area of the rotor / stator system.

With a view to a simple and rapid conversion of the homogenizer as needed, the actuator can be removed in particular together with the stator axially displaceable thereon, wherein on the provided with a frontal inlet opening a stator can be fixed, of which in the mounting position of the lid at least an axial section to form the shear gap is arranged radially adjacent to the rotor, so that during assembly of the cover provided with the additional inlet, a stator is automatically arranged in a first position and consequently immediately act on the sucked further material component very high shear forces to a homogeneous Eindispergierung same, optionally with mechanical comminution to provide. If, on the other hand, a more gentle dispersion of dispersion is desired, for example in the case of material components which are sensitive to mechanical action, the cover can of course not be equipped with a stator, or the stator can in particular be fastened detachably to the cover provided with the additional inlet in order to be able to do so to be able to remove or put on. The latter can be done with respect to a simple and quick installation, preferably by means of a quick release, such as a latching connection.

Alternatively or additionally, it may of course also be provided that the housing, e.g. at the inlet opposite side of the rotor / stator system or on the side facing the same, at least one second inlet for the task of an additional substance component, wherein such a second outlet should be suitably closed by means of a shut-off. In this case, by adjusting the stator between its first and second position when opening the obturator on the occasion of a desired dispersing a further material component in turn for a high shear (with the located in a first position stator) or for a very low shear to practically zero (with the stator in the second position) are taken care of.

Fig. 1

eine perspektivische Ansicht einer Ausführungs- form eines erfindungsgemäßen Homogenisators in teilweise geschnittener Darstellung;

Fig. 2

einen Längsschnitt durch den Homogenisator gemäß Fig. 1;

Fig. 3

eine perspektivische Explosionsdarstellung des Rotor-/Statorsystems des Homogenisators gemäß Fig. 1 und 2 einschließlich seiner Förder- und Mischeinrichtung sowie des Stellantriebs seines Stators; und

Fig. 4

eine der Fig. 3 entsprechende Explosionsdarstel- lung des Homogenisators gemäß Fig. 1 bis 3, wobei ein den Stellantrieb tragender Gehäusedeckel ge- gen einen mit einer stirnseitigen Einlaßöffnung zur Aufgabe einer zusätzlichen Stoffkomponente versehenen Deckel ausgetauscht worden ist.

Further features and advantages of the invention will become apparent from the following description of an embodiment with reference to the drawings. Showing:

Fig. 1

a perspective view of an embodiment of a homogenizer according to the invention in a partially sectioned representation;

Fig. 2

a longitudinal section through the homogenizer according to Fig. 1 ;

Fig. 3

an exploded perspective view of the rotor / stator system of the homogenizer according to Fig. 1 and 2 including its conveying and mixing device and the actuator of its stator; and

Fig. 4

one of the Fig. 3 corresponding exploded view of the homogenizer according to Fig. 1 to 3 in which a housing cover carrying the actuator has been replaced by a cover provided with an end inlet opening for discharging an additional substance component.

In Fig. 1 an embodiment of a homogenizer 1 is reproduced, which has a substantially circular cylindrical housing 2, in which one below with reference to Fig. 2 to 4 rotor / stator system explained in more detail as well as a mixing and a conveying device with a conveying element designed in the manner of a screw conveyor are rotatably mounted on a shaft extending axially in the housing 2. At the in Fig. 1 left, upper end of the homogenizer 1 this is closed by a flange 3, on the side facing away from the homogenizer 1, a controllable drive motor (not shown) is mounted to the shaft of the rotor and the conveying and mixing device with the respective desired speed in rotation to be able to put. In the region of its end facing the flange 3, the housing 2 of the homogenizer 1 is provided with an inlet 4 for applying the flowable substances to be homogenized or dispersed. In addition, further inlets 4a may be provided to enforce additional substances to be mixed into the flowable substances and / or to connect measuring devices such as thermometers, barometers or the like or to make the housing 2 more accessible, for example for the purpose a cleaning, wherein the inlets 4a, for example by means of cover (not shown) are closed. In the axial region of the rotor has the Housing 2 a radially arranged outlet 5 for the mixed / homogenized product, which also here additional outlets 5a (see, in this regard, the sectional view of Fig. 2 , in the sectional plane of the main outlet 5 is not recognizable for the product) may be provided, which serve largely for the same purposes as the above-mentioned, optional additional inlets 4a and also by means of lid (not shown) can be closed.

The homogenizer 1 may for example be part of an in Fig. 1 Not shown homogenizing be, which comprises a stirred tank (also not shown), from which branches off a line opening into the inlet 4 of the homogenizer 1 line. In this case, the outlet 5 of the homogenizer either flows back into the stirred tank or feeds the finished homogenized product to further processing steps or to a filling.

As in particular from Fig. 2 and 3 it can be seen extending inside the housing 2 of the homogenizer 1 with the seated on the flange 3 drive (not shown), for example via a shaft coupling 11, connected shaft 12, which by means of a seal 13, such as a mechanical seal against the flange is sealed. On the one hand, for example, substantially helically formed conveying elements 26 of a conveying device 25 and, on the other hand, a rotor 16 arranged downstream thereof (see in particular FIG Fig. 3 ), which cooperates with a stationary, ie non-rotatably arranged stator 17. The conveyor 25 and the rotor 16 are thus in the present case together by means of the drive (not shown) in rotation displaceable, wherein the rotor 16 optionally decoupled from the drive can be, for example, by axial displacement of the shaft 12 in the direction of the flange 3 (arrow P of Fig. 3 ), so that the free end 12 a of the shaft 12 is disengaged from the rotor 16.

Again, in particular the Fig. 3 it can be seen, the rotor 16 comprises in the present embodiment, an outer rotor blade 16a and an inner rotor blade 16b, which are arranged coaxially with each other and driven in rotation by the shaft 12 together. Both rotor blades 16a, 16b are provided in axial directions with openings, which in particular are aligned with each other and ensure a more or less unobstructed axial passage of the product. The rotor blades 16a, 16b have substantially the shape of a cylinder jacket with openings, or slots, in particular of different size and shape, which are released in the circumferential direction. Thus, the openings or slots 22 of the outer rotor blade 16a are formed, for example, approximately rectangularly between the cylinder jacket defining, blade-like elements, while the openings 21 of the inner rotor blade 16b are formed for example by the cylinder jacket passing through slots. The stator 17 arranged radially in a first position between the outer 16a and the inner rotor blade 16b also has substantially the shape of a cylinder jacket and is also open in the axial direction. In the circumferential direction of the cylinder jacket distributed openings 23 of the stator 17 have, for example, a slot shape of smaller width than the openings / slots 21,22 of the rotor blades 16a, 16b. In the assembled state according to Fig. 2 engages the stator 17 in a first position in each case to form a radial shear gap between the rotor blades 16a, 16b of the rotor 16 to provide for homogenization or dispersion of the product due to the introduction of shear forces, wherein the stator 17 in at least a first position, for example substantially over its entire axial extent radially between the rotor blades 16a, 16b of the rotor 16 is arranged.

The conveying device 25 has, as already indicated above, approximately helical conveying elements 26, which extend around at least a portion of the circumference of its axis of rotation, ie the shaft 12, and from there to the area of the surrounding inner wall of the housing 2, leaving only one narrow gap of, for example, about 0.5 mm. The inner wall of the housing 2 narrows (viewed in the conveying direction) in the region of the conveying elements 26 for the purpose of a suitable pressure build-up in the homogenizer 1, wherein the free - Umfangssseitige- end of the conveying elements 26, for example, according to the taper of the inner wall of the housing 2 provided with a chamfer can be (cf. Fig. 2 ). In addition, the homogenizer 1 is equipped with a mixing device 15, which in the present embodiment, upstream of the conveyor 25, for example, between this and the rotor 16, is arranged, but also downstream thereof may be positioned (not shown). The mixing device 15 has in the drawing reproduced embodiment, a plurality of fixed to the shaft 12 mixing vanes 14, which are arranged slightly inclined with respect to their axis of rotation and thus configured substantially in the form of propellers and each only a part of the scope of their Extend axis in the form of the shaft 12, wherein they are arranged distributed in the circumferential direction thereof. In the embodiment shown, the mixing blades extend 14, for example, at an angle of about 30 ° to 60 ° around the circumference of the axis of rotation, wherein - also viewed in the circumferential direction - between the mixing vanes 14, an at least about the same size or larger contrast gap is provided. The mixing blades 14 may be provided with perforations, which additionally provide for a gentle mixing or homogenizing effect.

The stator 17 is, as already indicated, in the in Fig. 2 illustrated operating situation in a first position in which it is in each case radially adjacent to the rotor 16 - or more precisely: radially between the two rotor elements 16a, 16b - is arranged so that between the stator 17 and the two rotor elements in each case a shearing gap is formed downstream of the same the homogenized product leaves the housing 2 of the homogenizer 1 via the outlet 5. According to the invention, the stator 17, as in particular from Fig. 2 and 3 at least between this first position and a second, in Fig. 2 not shown position - here: linear in the direction of arrow V - with respect to the rotor 16 displaceable, in which the stator 17 in the axial direction next to (in Fig. 2 right) the rotor 16 is arranged so that between the blades 16a, 16b of the rotor 16 and the stator 17 no more shear gaps are present. In the present embodiment, an actuator 30 is provided for this purpose, which comprises, for example, several (here: three) fluidly, eg hydraulically actuated, piston / cylinder units 31 whose pistons are mounted on a carrier 32 (FIG. Fig. 2 ) of the actuator 30 are mounted and their cylinder with the in Fig. 2 right, the flange 3 facing away from the end 17a of the stator 17 are connected. If the pistons of the piston / cylinder units 31 are consequently subjected to pressurized fluid, the stator 17 is moved into its first, in Fig. 2 shown position in the direction of arrow V (in Fig. 2 to the left); If, on the other hand, the pistons of the piston / cylinder units 31 are evacuated, then the stator 17 is displaced to the right in the direction of the arrow V, until it abuts, for example, against a stop predetermined by the stop of the pistons in the cylinders, in which case it is preferably below a certain limit axial distance from the rotor 16 of, for example, a few millimeters is arranged. Because of the drive of the shaft 3 independent actuator 30, such a displacement of the stator 17 during the operation of the homogenizer 1, that is done with a rotating rotor 16.

As further in particular the Fig. 2 and 3 can be seen, the actuator 30 of the stator 17 is fixed in the embodiment shown on a front side of the housing 2 of the homogenizer 1 closing lid 33, which of a with a fluid connection 35 (FIG. Fig. 1 ) cap 34 (in Fig. 3 not shown) can be closed to accommodate the actuator 30 protected from external influences.

In order to open the homogenizer 1 another application, namely the Eindispergieren an additional component while reliably avoiding lumping and very fine particulate matter, in the present embodiment, the cover 33 with the actuator 30 of the housing 2 is removable and against a in the Fig. 4 reproduced cover 40 with a frontal inlet opening 41 for the task of such a substance component interchangeable. Otherwise corresponds to in Fig. 4 in exploded view homogenizer according to Fig. 1 to 3 , wherein identical parts are provided with the same reference numerals are. How out 3 and 4 can be seen in this context, the cover 33 with the actuator 30 together with the fixed to the piston / cylinder units 31 stator 17 and can be provided at the with the additional, at the inlet 4 opposite side of the rotor 16 arranged inlet opening 41 Lid 40 a corresponding stator 17b to be fixed, which in turn to form a shearing gap between itself and the blades 16a, 16b of the rotor 16 in the assembled state of the lid 40. If a gentle, preferably low-shear dispersion is desired, the cover 40 can of course also carry no stator, so that the substance component introduced via the inlet 41 is merely dispersed by the rotating rotor 16.

The homogenizer 1 according to Fig. 1 to 3 can operate essentially in two different operating modes, on the one hand in a "shear mode" according to conventional homogenizers with a rotor / stator system, on the other hand in a pure "pump mode" bypassing the or between the rotor 16 and stator 17 formed shear gap (s):

In "shear mode", the stator 17 is in the in Fig. 2 reproduced first position, in each of which a radial shear gap between the stator 17 and the rotor blades 16a, 16b is formed. The product to be homogenized enters via the inlet 4 in the housing 2 of the homogenizer 1, passes the mixing device 15 over the conveyor 25 to the rotor / stator 16, 17, wherein it under high shear between the rotor blades 16 a, 16 b and the shear column formed by the stator 17 passes through and leaves the homogenizer 1 through the outlet 5. Depending on the desired degree of shear, the rotational speed of the rotor / stator system 16, 17 are freely selected by means of the controllable drive. As far as only a single, the rotor 16, the conveyor 25 and the mixing device 15 common drive 4 is provided, as is the case in the present embodiment, the conveyor 25 rotates in the "shear mode" together with the rotor 16 and the mixing device 15, which ensures a certain pre-homogenization.

In "pump mode", the stator 17 is located in the Fig. 2 reproduced first position shifted so far to the right in the second position that it is arranged axially adjacent to the rotor 16 and consequently no radial shear gap between the stator 17 and the rotor blades 16a, 16b longer exists. The product to be homogenized in turn enters the housing 2 of the homogenizer 1 via the inlet 4, passes the mixing device 15 and via the conveyor 25 to the rotor blades 16a, 16b of the rotor 16, which radially displaces it while avoiding the passage of a shear gap penetrated outside, after which it leaves the homogenizer 1 through the outlet 5. The conveyor 25 is able to ensure a sufficient flow rate even at low speeds, while the mixing device 15, a very gentle homogenizing effect when passing the, provided here with the perforations, mixing blades 14 is ensured. As far as only a single, the rotor 16, the conveyor 25 and the mixing device 15 common drive 4 is provided, as is the case in the present embodiment, the rotor 16 rotates in the "pumping mode" together with the conveyor 25 and the mixing device 15 with but, if desired, can also be decoupled from the shaft 12.

Claims (18)

1. A homogeniser (1) for homogenising or dispersing fluid substances, having a shaft (12) which supports a rotor (16), the shaft (12) being rotatably supported and being rotably driven by means of a drive that is, in particular, controllable, and having a stator (17) that interacts with the rotor (16), wherein at least one shear gap is formed between the rotor (16) and the stator (17), characterised in that the stator (17) is axially displaceable in relation to the rotor (16) between at least one first position, in which at least one axial section of the rotor (17) is arranged radially adjacent to the rotor (16) with the formation of the shear gap, and a second position in which the stator (17) is arranged adjacent to the rotor (16) in the axial direction, so that a shear gap is no longer present between the rotor (16) and stator (17).
2. The homogeniser according to Claim 1, characterised in that the stator (17) is arranged in the second position with an axial distance from the rotor (16), wherein the stator (17), particularly in the second position, abuts against a stop arranged on the side of the stator (17) facing away from the rotor (16).
3. The homogeniser according to Claim 1 or 2, characterised in that the stator (17), in at least one first position, is arranged radially adjacent to the rotor (16) essentially along its entire axial extension.
4. The homogeniser according to any one of Claims 1 to 3, characterised in that

   - the stator (17) is displaceable exclusively between a first position and the second position in relation to the rotor (16); or in that

   - the stator (17) is also displaceable relative to the rotor (16) between a plurality of first positions in which the stator (17) is in each case arranged radially adjacent to the rotor (16) at least with an axial section.
5. The homogeniser according to any one of Claims 1 to 4, characterised in that the rotor (16) is arranged in axially fixed manner and the rotor (17) is displaceable in the axial direction.
6. The homogeniser according to any one of Claims 1 to 5, characterised in that a conveying device (25) is arranged before the rotor/stator system formed from rotor (16) and stator (17).
7. The homogeniser according to any one of Claims 1 to 6, characterised in that the rotor/stator system (16, 17) and, if necessary, the conveying device (25), are accommodated in a housing (2) in which is mounted the shaft (12) supporting the rotor (16), wherein the housing (2), in particular,

   - has at least one inlet (4) arranged upstream from the rotor/stator system (16, 17), which inlet is connectable, in particular, to a branch pipe of a tank equipped, in particular, with an agitator; and/or

   - has at least one outlet (5) arranged downstream from the rotor/stator system (16, 17), which outlet is connectable, in particular, to a return pipe of a tank equipped, in particular, with an agitator.
8. The homogeniser according to Claim 7, characterised in that the outlet (5) of the housing (2) is arranged radially relative to the shaft (12) supporting the rotor (16) and in the axial region of the rotor/stator system (16, 17).
9. The homogeniser according to any one of Claims 6 to 8, characterised in that the conveying device (25) has at least one conveying element (26) displaceable coaxially with the shaft (12) of the rotor (16), wherein the conveying device (25) is arranged, in particular, on a section of the housing (2) which reduces in width on the inside - viewed in the direction of conveying.
10. The homogeniser according to any one of Claims 1 to 9, characterised in that it also has a mixing device (15), wherein the mixing device (15) has, in particular, at least one or more mixing blades (14) displaceable rotatably and coaxially with the shaft (12) of the rotor (16).
11. The homogeniser according to any one of Claims 6 to 10, characterised in that

    - the rotor (16) and the conveying device (25) and/or the mixing device (15) are commonly rotatably displaceable, in particular by means of one and the same drive, wherein the rotor (16) and/or, if necessary, the mixing device (15) is/are, in particular, disconnectable from the drive; or in that

    - the rotor (16) on the one hand, the conveying device (25) on the other and, if necessary, the mixing device (15), are driven independently of each other.
12. The homogeniser according to any one of Claims 1 to 11, characterised in that the rotor (16) and the stator (17) have essentially the shape of a cylinder jacket with radial openings or slots (21, 22, 23) let into the jacket and arranged so that they are distributed in the circumferential direction, wherein the radial openings (21, 22) of the rotor (16) have, in particular, a different shape and/or size from the openings (23) of the rotor (17).
13. The homogeniser according to any one of Claims 1 to 12, characterised in that an actuator (30) is provided for displacing the stator (17) relative to the rotor (16), which actuator can be actuated, in particular, whilst the rotor (16) is rotating, wherein the actuator (30) is fastened, in particular, on a cover (33) sealing the housing (2) of the homogeniser (1) on the front side.
14. The homogeniser according to Claim 13, characterised in that the cover (33) with the actuator (30) can be removed from the housing (2) of the homogeniser (1) and can be replaced by a cover (40) provided with a front-side inlet opening (41) for feeding an additional substance component, wherein the actuator (30) can, in particular, be removed together with the stator (17) axially displaceable thereon.
15. The homogeniser according to Claim 14, characterised in that a stator (17b) is fixedly arranged on the cover (40) provided with a front-side inlet opening (41), of which, in the mounting position of the cover (40), at least one axial section is arranged with the formation of the shear gap radially adjacent to the rotor (16).
16. The homogeniser according to any one of Claims 7 to 15, characterised in that the housing (2) has at least one second inlet (4a, 41) for feeding an additional substance component, wherein the second inlet (4a, 41) is sealable, in particular, by means of a shutoff mechanism.
17. A homogenising device for homogenising or dispersing fluid substances, with a tank equipped, in particular, with an agitator and with at least one branch pipe branching from the tank and leading into an inlet (4) of a homogeniser (1), characterised by a homogeniser (1) according to any one of Claims 1 to 16.
18. The homogenising device according to Claim 17, characterised in that at least one outlet (5) of the homogeniser (1) opens into the tank by means of a return pipe.

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