EP2001581B1 - Homogenizer - Google Patents

Abstract

The invention relates to a homogenizer (11, 11', 11'') for the production of free-flowing products, for example, emulsions, suspensions or similar products, comprising a rotor (13, 13', 13'') with rotor blades (20, 21, 22) and driven by a motor (27) and a stator (14, 14', 14'') with flow elements (23, 24) which may be rotated. According to the invention, the design of conventional homogenizers with rotating stators may be simplified by provision of a coupling device (34, 35, 36, 39, 46) for the selective coupling or decoupling of the stator (14, 14', 14'') to or from the rotor (13, 13', 13''), wherein in a coupled state the stator (14, 14', 14'') is driven by the rotor (13, 13', 13'').

Description

The invention relates to a homogenizer for the production of flowable products, for example. Emulsions, suspensions or similar products, with a rotor blades having and drivable by a motor rotor and a flow elements having rotatable stator.

Such homogenizers are conventionally mounted under containers to mix and homogenize the contents of the container. Such a homogenizer has in addition to the rotor drivable by a motor and a circular annular stator whose flow elements are arranged at least partially between two - each arranged along concentric circular lines - groups of rotor blades.

In operation of the homogenizer, i. with a rotating rotor, the product flows from inside to outside, similar to a centrifugal pump. It occurs through openings provided between the flow elements of the stator. In such a passage, the product is subjected to shearing forces and turbulence. This leads to a good mixing of the product and thus to a homogeneous end product. With the aid of such a homogenizer, a large number of flowable products, such as e.g. Emulsions and suspensions.

However, under certain conditions, such shear and turbulence effects on the product are undesirable. Namely, they reduce product throughput through the homogenizer, especially as the viscosity of the product increases, and slow down the production process during the process Pumping the product in the container located above the homogenizer or during the discharge of the product from the container.

In special applications, the homogenizer can also be used as a cleaning pump. When cleaning, it is mainly on a high throughput of the washing liquid. Therefore, a reduction of the throughput, due to the flow resistance of the stator, is disadvantageous even in such a cleaning process.

In order to improve the pumping action of a homogenizer, additional devices are known in which additional conveying elements in the form of pumping blades are mounted behind the stator. It is conventionally also provided a special tooth geometry in which, depending on the direction of rotation of the rotor, a larger passage cross-section for the medium flowing through the stator can be realized as in the opposite direction of rotation. In this opposite direction of rotation - due to the geometry - the passage of the product considerably more difficult.

In these known homogenizers, however, the differential speed between the rotating rotor and the stationary stator causes a more or less high shear, depending on the speed of the rotor.

An example of such a homogenizer can be found in DE 37 15 331 C2 , Another example of such a homogenizer can be found in EP-A-0307318 ,

A disadvantage of such known homogenizers is that a promotion of the product without shearing is not possible. This can cause unwanted effects, especially in the case of sensitive products, in which, for example, the acting shear forces cause changes in the structure of the product.

Out DE 200 02 920 U1 Another homogenizer is known in which the homogenization effect can be influenced and the shearing action and the pumping action should be adaptable to the respective requirements. For this purpose, the stator of this homogenizer is also a rotatable element, and therefore rotatable Stator formed. However, the rotatable stator is driven independently of the rotor. For such an independent drive of rotor and stator, however, two drive motors are necessary. However, such drive motors are complicated and expensive. In addition, two drive motors require essentially twice the maintenance. In addition, the probability of failure of the homogenizer and thus the probability of a plant shutdown doubles. In addition, two drive motors also lead to an increased space requirement, which often leads under a container to a very narrow and therefore only consuming to maintain and clean construction.

The invention is therefore based on the problem of providing a simplified homogenizer which eliminates the aforementioned disadvantages of known homogenizers.

The invention solves this problem by means of a homogenizer of the type mentioned, which further comprises a coupling device for selectively coupling or decoupling the stator with and from the rotor, wherein in a coupled state, the stator is driven by the rotor.

In connection with the present invention, the term "stator" is not to be understood as meaning that the stator is permanently fixed. Rather, the stator can be operated in a fixed or in a rotating mode. That the stator is - as well as the rotor - rotatable.

Thanks to the invention, only one drive motor for the homogenizer, namely only needed for the rotor. In the coupled state in which the stator also rotates, however, no second drive motor is used to drive the stator. Rather, the drive of the stator is done by the rotor. For this purpose, the coupling device couples the stator to the rotor. The coupling device advantageously creates a mechanical connection between a drive shaft of the rotor and the stator, so that the stator is carried along by the rotor and driven with it.

Advantageously, rotate in the coupled state of the rotor and the stator in the same direction, so that the shearing action between the rotor and stator is reduced. If the stator and the rotor rotate at the same speed, the shearing effect is even canceled.

Preferably, the stator is fixed in a decoupled state of the rotor and stator. The stator is therefore designed lockable by means of a locking device. Advantageously, the locking device is designed as a clamping device or brake.

Advantageously, the coupling device has a mechanical or electromechanical coupling with which the rotor and the stator are mechanically connectable. In the coupled state, the rotor and the stator are preferably connected rigidly to each other. The coupling may be formed either mechanically or electromechanically. Advantageously, the coupling is formed electromagnetically switchable. For example. can be actuated by energizing an electromagnet, the clutch, in particular closed or opened, are.

Preferably, the clutch is designed to be automatically switching or externally switched. An automatically switching clutch can automatically establish the coupled state in the presence of certain operating conditions. In contrast, an externally connected clutch couples or decouples rotor and stator as a function of an external switching request. This switching request can be supplied to the homogenizer either by an operator or by a control device.

In a preferred embodiment, the clutch on driver and cam. This means that a particularly simple coupling between the rotor and stator can be achieved.

In a further preferred embodiment, the coupling device is designed such that in a first direction of rotation of the rotor, the rotor is coupled to the stator such that the rotor entrains the stator, and that in a second, opposite to the first direction of rotation, the rotor and the stator are decoupled from each other.

In this embodiment, in the first direction of rotation of the rotor, the stator rotates with, i. the stator is driven by the rotor. In contrast, the rotor and the stator are decoupled from each other in the second direction of rotation. In particular, then the stator is locked or determined.

In the decoupled state, the homogenizer can be operated in its original mode of operation in which shearing effects on the product are exerted on the product by a differential speed between fixed stator and rotating rotor. In the opposite direction of rotation of the rotor, however, the stator is taken from the coupled rotor and rotated. The mechanical coupling device thereby causes the speed of the stator is in a fixed unchangeable relationship to the speed of the rotor, for example. Rotate the rotor and stator in the same direction at the same speed, so that no shear forces are exerted on the product.

However, the original mode of operation of the fixed stator and rotary rotor homogenizer may be in the opposite direction of rotation, i. be performed in the second direction of rotation to introduce shear energy and turbulence in the product. In one direction of rotation coupled rotor and stator thus the homogenizer can be used in the pumping operation, while it is used in the opposite direction of rotation in the original Homogenisierbetrieb. Thus, it is not necessary to resort to additional facilities such as circulating or cleaning pumps in pumping.

In a further particular embodiment, the coupling device is designed as an overrunning clutch. An overrunning clutch is particularly suitable easy way to rotate the stator with the rotor. The principle of such overrunning clutches is used, for example, in bicycles. By reversing the direction of rotation, either the stator is taken away or decoupled from the rotor. In the case of coupling or entrainment of the stator by the rotor, the stator and rotor rotate at the same speed. Advantageously, there is no differential speed between rotor and stator. Thus, no shear is exerted on the product as it passes through the homogenizer. Further, in this mode of operation, the resistances to the passage of the product through the homogenizer are reduced. In addition, the turbulence is reduced to the product. This is advantageous because it thus receives a higher pumping action, ie conveying effect of the homogenizer.

In a further preferred embodiment, the coupling device to a transmission which is designed such that in the coupled state of the rotor and stator is a fixed speed ratio of the rotational speed of the rotor to the rotational speed of the stator. However, the transmission is only effective in the coupled state, i. especially only in the o.g. first direction of rotation of the rotor, in which the rotor rotates the stator.

In this embodiment, the stator may rotate in the coupled state at a higher or lower speed than the rotor. The speed is specified by the gearbox.

In a further preferred embodiment, the coupling device is designed such that in the coupled state, the rotor and the stator are rotatable in the same or opposite direction of rotation. In the case of the same direction of rotation there is no or only a slight difference in speed between rotor and stator, while in the case of opposite direction of rotation a particularly high differential speed between rotor and stator is achieved. Thus, increased shear forces could be registered on the product. An advantage of this embodiment is that in the opposite direction of rotation, ie in mating mode or overtaking, between the rotor and stator despite increased differential speed and shearing no second drive unit is necessary. This leads to a cost-effective and space-saving design.

The coupling device is designed such that it either allows either a concurrent or opposite operation of the rotor and stator. In this case, appropriate switching devices are provided on the homogenizer.

In an alternative embodiment, however, the homogenizer allows either only an opposite operation of rotor and stator or only a concurrent operation of rotor and stator.

Fig. 1

einen unterhalb eines Behälters angeordneten erfindungsgemäßen Homogenisator zum Homogenisieren eines Produkts im Umlauf;

Fig. 2

einen unterhalb eines Behälters angeordneten erfindungsgemäßen Homogenisator zum Homogenisieren eines Produkts im Behälter;

Fig. 3

ein erstes Ausführungsbeispiel mit einer mechanischen Kupplung eines erfindungsgemäßen Homogenisators in einer seitlichen Schnittansicht sowie in einer Schnittansicht von oben;

Fig. 4

ein erstes Ausführungsbeispiel mit einer Freilaufkupplung eines erfindungsgemäßen Homogenisators in einer seitlichen Schnittansicht und

Fig. 5

ein erstes Ausführungsbeispiel mit einem Getriebe und einer elektromechanischen Kupplung eines erfindungsgemäßen Homogenisators in einer seitlichen Schnittansicht.

Further advantageous embodiments will become apparent from the dependent claims and from the closer explained with reference to the accompanying drawings embodiments. In the drawing show:

Fig. 1

a homogenizer according to the invention arranged below a container for homogenizing a product in circulation;

Fig. 2

a homogenizer according to the invention arranged below a container for homogenizing a product in the container;

Fig. 3

a first embodiment with a mechanical coupling of a homogenizer according to the invention in a lateral sectional view and in a sectional view from above;

Fig. 4

a first embodiment with a one-way clutch of a homogenizer according to the invention in a lateral sectional view and

Fig. 5

a first embodiment with a gear and an electromechanical coupling of a homogenizer according to the invention in a lateral sectional view.

Fig. 1 shows a arranged below a container 10 homogenizer 11 with a drive shaft 12 connected to a rotor 13 and a rotatable stator 14th

In the container 10 is a product to be mixed and finely processed, which is homogenized by means of the homogenizer 11 and circulated. The product passes through an opening 15 from the container 10 into the homogenizer 11 and is transported in the homogenizer radially or obliquely from the inside to the outside. The product is then conveyed out of the homogenizer 11 via a circulation line 16 and either back into the container 10 or drained via a valve 17.

Fig. 2 shows another embodiment of the attachment of a homogenizer 11 to a container 10 '. The homogenizer corresponds in its construction to the in Fig. 1 However, in addition to the centrally arranged opening 14, the container 10 'has further radially outer openings 18, through which the product is conveyed by the homogenizer 11 back into the container 10'. In this embodiment, an internal homogenization of the container contents is made possible, ie the product is returned directly from the output of the homogenizer back into the container.

However, the invention is not limited to the attachment of a homogenizer to a container. Rather, according to the invention, a homogenizer can also be installed in or on a pipeline or elsewhere in a processing process.

Fig. 3 shows the in the Fig. 1 and 2 only shown schematically homogenizer 11 in detail. The upper part of Fig. 3 shows the homogenizer 11 in a side sectional view, while the lower part of Fig. 3 shows the homogenizer 11 in a horizontal sectional view.

Such a homogenizer 11 is also referred to as Zahnkranzdispergiermaschine. The rotor 13 has a disk-like base element 19 on which a group of rotor blades 20 are arranged along a circular line. Along a further circular line, which is arranged concentrically to the aforementioned circular line, there is another group of rotor blades 21. Finally, a third group of rotor blades 22 is located along another concentrically arranged circular line.

Between each pair of groups of rotor blades is a group of flow elements between the group of rotor blades 20 and the group of rotor blades 21 a group of flow elements 23. Furthermore, there is another group between the group of rotor blades 21 and the group of rotor blades 22 Both the group of flow elements 23 and the group of flow elements 24 are each arranged along a circular line arranged concentrically to the above-mentioned circular lines.

Although the present embodiment has been illustrated with three groups of rotor blades 20, 21, 22 and two groups of flow elements 23, 24 of the stator 14. However, in other embodiments, other numbers of groups of rotor blades or flow elements are also provided. In the simplest case, a homogenizer has only one group of rotor blades, which are arranged along only one circular line, and only one group of flow elements of the stator, which are likewise provided only along a circular line arranged concentrically to the aforementioned circular line.

The flow elements 23, 24 are arranged on a further base element 25 of the stator 14.

The rotor 13 is connected via a drive shaft 26 to a drive motor 27. A flowable product passes through an opening 28 in the homogenizer 11 and a discharge device 29 from the homogenizer 11 out.

The stator 14 is formed as a rotatable stator. It is therefore mounted on a housing 31 of the homogenizer 11 by means of a bearing 30, in particular a ball bearing.

Between the stator 14 and the rotor 13 is another bearing 32, in particular ball bearings, which allows a relative rotational movement between the rotor 13 and the stator 14.

The stator 14 has a shaft 33, which is designed as a hollow shaft and through which the drive shaft 26 of the rotor 13 passes. This shaft 33 can be coupled via cams 34 and an axially displaceable driver 35 or a shift sleeve with cams 36 provided on the drive shaft 26.

Im in Fig. 3 shown state rotor 13 and stator 14 are not coupled together, but decoupled. However, if the driver 35 is brought into an upper switching position, a coupling of rotor 13 and stator 14 takes place.

The driver 35 is moved either manually or by means of an adjusting device axially to produce the coupled or the decoupled state.

In a non-illustrated embodiment, a locking device for selectively detecting the status 14 is also provided. By means of the locking device, the stator 14 can be locked or released, to then be operated as a rotating stator 14 can. The locking device may be formed in particular as a brake or clamping device.

As shown by the arrows 37, 38, the drive shaft 26 of the rotor 13 can be rotated in both directions of rotation.

Fig. 4 shows a further embodiment of a homogenizer 11 'according to the invention. The homogenizer 11 'largely corresponds to the in Fig. 3 Homogenizer 11. The same reference numerals are therefore used for the same parts. Furthermore, only the differences are compared Fig. 3 explained, with unexplained elements accordingly Fig. 3 are formed.

This in Fig. 4 shown embodiment uses as a coupling device between the rotor 13 'and the stator 14' an overrunning clutch 39. This overrunning clutch 39 causes, in a first rotational direction according to the reference numeral 37 of the rotor 13 ', the drive shaft 26' of the rotor 13 'with the drive shaft 33' the rotatable stator 14 'is coupled. That is, the rotor 13 'and the stator 14' rotate both in the same direction of rotation 37th

In the opposite direction of rotation according to reference numeral 38, however, the rotor 13 'is decoupled from the stator 14', wherein the stator 14 'is stationary.

The drive shaft 26 'of the rotor 13' is supported by means of a further bearing 40, in particular ball bearing, against the housing 31 'of the homogenizer 11'. The shaft 33 'of the rotor 13' is connected via the one-way clutch 39 to the shaft 26 'of the rotor 13' in the manner described above.

Fig. 5 shows a further embodiment of a homogenizer 11 "In this embodiment, the coupling device for coupling rotor 13" and stator 14 "has a gear 41. The shaft 33" of the stator 14 "has a toothed ring or gear-shaped section 42. This portion 42 is engaged with a first gear 43 of the gear 41, which in turn is rotationally connected via a shaft 44 to a second gear 45. This second gear 45 is in communication with an electromechanical clutch 46. This electromechanical clutch 46 has an electromagnet In the engaged state, the gear 45 is connected to the drive shaft 26 "of the rotor 13." By actuating the electromagnet is a torsionally rigid, in particular positive or frictional connection between the drive shaft 26 "and the gear 45 and thus also with the stator 14" created.

By means of the gear 41, a fixed speed ratio between the rotational speed of the rotor 13 "and the stator 14" can be predetermined. The transmission 41 may also have a plurality of shift stages with a plurality of fixed predefined speed ratios. In addition, the gear 41 can also cause a reversal of rotation, so that, for example, the rotor 13 "rotates in the direction of rotation 37, while the stator 14" rotates in the direction of rotation 38. By this measure, the differential speed between rotor 13 "and stator 14" can be significantly increased to exert increased shear forces on the product.

Overall, the invention provides a homogenizer with a rotor and a rotatable stator, in which the rotatable stator can be optionally coupled to the rotor, so that the rotation of the stator is dependent on the rotation of the rotor. In this way, the pumping action of a homogenizer can be significantly improved without additional drive motors. It only requires a coupling device for coupling the stator and rotor.

Claims (10)

1. A homogeniser for the production of free-flowing products, for example, emulsions, suspensions or similar products, comprising a rotor (13, 13', 13") having rotor blades (18, 19, 20) and drivable by means of a motor (27), and a rotatable stator (14, 14', 14") having flow elements (23, 24)
   characterised by
   a coupling device (34, 35, 36; 39; 46) for the selective coupling or decoupling of the stator (14, 14', 14") with or from the rotor (13, 13', 13") in such a manner that in a coupled state, the stator (14, 14', 14") can be driven by the rotor (13, 13', 13").
2. The homogeniser according to claim 1,
   characterised in that
   in a decoupled state of rotor (13, 13', 13") and stator (14, 14', 14"), the stator (14, 14', 14") is fixed, in particular locked.
3. The homogeniser according to claim 1 or 2
   characterised in that
   the coupling device (34, 35, 36; 39; 46) comprises a mechanical (34, 35; 39) or electromechanical (46) coupling by which means the rotor (13, 13', 13") and the stator (14, 14', 14") can be connected mechanically.
4. The homogeniser according to claim 3,
   characterised in that
   the coupling (34, 35, 36; 39; 46) is configured to be electromagnetically switchable.
5. The homogeniser according to claim 3 or 4,
   characterised in that
   the coupling (34, 35, 36; 39; 46) is configured to be independently switching or externally switched.
6. The homogeniser according to claim 5,
   characterised in that
   the coupling comprises entrainers (35) and cams (34).
7. The homogeniser according to any one of the preceding claims,
   characterised in that
   the coupling device (34, 35, 36; 39; 46) is configured in such a manner that in a first direction of rotation (37) of the rotor (13, 13', 13"), the rotor (13, 13', 13") is coupled to the stator (14, 14', 14") in such a manner that the rotor (13, 13', 13") entrains the stator (14, 14', 14") and that in a second direction of rotation (38) opposite to the first direction of rotation (37), the rotor (13, 13', 13") and the stator (14, 14', 14") are decoupled from one another.
8. The homogeniser according to any one of the preceding claims,
   characterised in that
   the coupling device is an overrunning clutch (39).
9. The homogeniser according to any one of the preceding claims,
   characterised in that
   the coupling device has a transmission (41) which is configured in such a manner that in the coupled state of rotor (13") and stator (14") a fixed rotational speed ratio of the rotational speed of the rotor (13") to the rotational speed of the stator (14") exists.
10. The homogeniser according to any one of the preceding claims,
    characterised in that
    the coupling device is configured in such a manner that in the coupled state, the rotor (13") and the stator (14") are rotatable in the same or opposite direction of rotation.

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