EP2363200B1 - Colloidal mixer and method, in particular for preparing building materials - Google Patents

Description

The invention relates to a colloidal mixer, in particular for the treatment of building materials, according to the preamble of claim 1. Such a colloidal mixer is formed with a mixing trough in which a premixing device and a dispersing device are arranged, and drive means for actuating the premixing device and the dispersing device. The invention further relates to a process for colloidal preparation.

For the preparation of low to high viscosity mixtures of liquid substances on the one hand and pulp-like or fine-grained substances on the other hand, various stirring and mixing machines are known. There are, for example, blade, paddle and worm stirrers with and without baffles known in which the stirring tools can be arranged radially, eccentrically, horizontally or vertically. In general, each of these known mixer is more or less specifically designed to produce a disperse system with a certain viscosity of predetermined liquid and solid starting materials.

If, however, the starting materials and / or their physical properties change, or if the composition of the mixture and / or its viscosity changes, a sufficient quality of mixing may no longer be ensured with the known stirring and mixing machines under certain circumstances. In the construction and building materials industry, however, it often happens that suspensions and dispersions of different composition and thus also a variety of rheological properties must be prepared. According to the prior art may then be required several differently designed mixer.

Against this background describes the DE 103 54 888 B4 a colloidal mixer, which should cover different viscosity ranges due to its construction. The mixing process within this known mixer takes place in two different process zones with different tasks and effects. In the premixing zone, the solids are roughly stirred into the liquid phase, and in the subsequent dispersing zone, a colloidal digestion of the solids and the finest distribution of the solids in the liquid takes place.

According to the DE 103 54 888 B4 it is provided that the mixing tools mounted in the premixing zone are rotationally connected to the dispersing tools mounted in the dispersing zone and that they are driven by a common drive unit. This has the advantage that a one-sided storage and thus a particularly simply constructed colloidal mixer is possible, which at the same time allows a secure torque transmission between the premixing device and the dispersing device. For example, after the DE 103 54 888 B4 the storage of the premixing device and the dispersing device on the bottom side of the mixing trough done.

US 5,549,384 A describes a colloidal mixer with a mixing trough in which a mixing tool and a dispersing tool are horizontally juxtaposed. Their axes of rotation are offset horizontally. Also at US 2006/0097093 A1 For example, a colloidal mixer comprises a mixing tool and a dispersing tool with mutually offset axes of rotation. Furthermore, also disclosed SU 1079460 A a colloidal mixer with two rotating devices whose axes of rotation are offset from each other.

Further colloidal mixers are described in DE 102 04 921 C1 . GB 2 124 096 A ,, DE 20 2009 001937 U1 . FR 1 386 227 A . FR 2 929 535 A1 , DE 21 29 549 A1 . DE 10 2008 060588 A1 . US Pat. No. 6,866,411 B1 and GB 2 355 415 A , in which DE 102 04 921 C1 and US Pat. No. 6,866,499 B1 jewäls a Kolloidalmischer according to the preamble of claim 1 reveal. The object of the invention is to provide a colloidal mixer and a method in which a particularly good mixing quality can be obtained in a particularly large range of applications.

The object is achieved by a colloidal mixer having the features of claim 1 and by a method having the features of claim 12. Preferred embodiments are given in the dependent claims.

The colloidal mixer according to the invention comprises that the premixing device and the dispersing device are rotationally coupled, and that two separate drives are arranged for independently driving premixing device and dispersing device, one drive being provided for the premixing device and a second drive for the dispersing device.

A basic idea of the invention can be seen in the prior art coupling of the mixing tools to the dispersing tools canceled and provided for each of the premixing and the dispersing a separate drive. Accordingly, according to the invention, the drive means on two separate drives. This makes it possible to provide a speed difference between the premixer and the disperser.

Among other things, the invention is based on the observation that the mixers known from the prior art with premixing device coupled to the dispersing device may reach their limits in certain mixtures, in particular in the mixing of solids-rich suspensions of high density from solids having a very low bulk density , Because of the coupling with the dispersing tools, the mixing tools of the premixing zone run at the same speed as the dispersing tools in such a mixer. However, the speed of the dispersing tools must be sufficiently high to allow the colloidal digestion of the solids. This high speed, the state of the art due to the coupling also in the premixing zone However, under certain circumstances, in the premixing zone, undesirable effects may now result, which prevent further solids of low bulk density from being stirred into a suspension of significantly higher density.

This problem can be met with the inventive arrangement. For the invention makes it possible, for example, to operate the dispersing device at a high speed, which enables the colloidal digestion to simultaneously operate the premixing device at comparatively low speed, so that it is still possible to stir in solids of low bulk density. Thus, according to the invention, mixtures of substances can be effectively processed which may not be accessible to prior art mixers. In particular, the mixer according to the invention can be used for the colloidal preparation of low to high viscosity suspensions and / or dispersions.

According to the invention, the premixing device has at least one mixing tool and the dispersing device has at least one dispersing tool, wherein the at least one mixing tool is rotationally actuated by the first drive, and the at least one dispersing tool is driven by the second drive. Thus, the mixing tools in the pre-mixing zone may operate separately from the dispersing tools in the dispersing zone. The rotation of the mixing tool and the dispersing tool takes place around a common axis of rotation, which may be arranged in particular at least approximately vertically and / or in the mixer center. Thus, the premixer and the disperser are designed for coaxial rotation of mixing tools and dispersing tools. According to a preferred development, the premixing device can have two mixing tools, which allows a particularly thorough mixing.

In particular, it can be provided according to the invention that the solids are coarsely stirred into the liquid phase in the premixing zone, and that in the subsequent dispersing zone a colloidal digestion of the solids and the ultrafine distribution of the solids in the liquid takes place.

The drives can have, for example, electric or hydraulic motors. The power transmission from the motors to the tools is expediently carried out via suitable drive shafts, it also being possible to provide suitable transmissions between the motors and the tools. The drive of the premixing and / or the dispersing device is thus possible either with fixed or variable speed and both hydraulically and by electric motor. The torque transmission can take place either directly via a shaft / hub connection from the respective motor shaft to the premixing device or to the dispersing device and in particular to the respective rotors. Alternatively, it can be provided that the premixing device and / or the dispersing device is in each case designed with its own shaft with bearing and seal, and the torque is transmitted by means of a clutch or belt or chain drive from the respective drive motor to the respective shaft.

The premixing device is arranged above the dispersing device. In this case, gravity may assist the transport of the medium from the premixer into the disperser.

For example, it can be provided that the drive of the premixing device takes place from above, and the drive of the dispersing device from below. Accordingly, it can be advantageous that the drive for the dispersing device is arranged at least partially below the dispersing device, and / or that the drive for the premixing device is arranged at least partially above the premixing device. As a result, a structurally particularly simple design receive. In particular, the drive for the premix device can be placed on a lid of the mixer. The drive for the dispersing device can also be located at least partially next to the mixing trough, as a result of which a particularly compact arrangement is obtained.

It can also be provided to drive both the mixing tool of the premixing device and the dispersing tool of the dispersing device from below. The drive for the premixing device has a hollow shaft, through which a drive shaft of the drive for the dispersing device is performed. Accordingly, the drive shaft for the mixing tool is designed as a hollow shaft, through the center of which the shaft is guided for driving the dispersing tool. As a result, a particularly compact design is given.

It is particularly preferred that the drive for the premixing device is set up for continuous operation or for intermittent operation of the premixing device, preferably in both directions of rotation. Accordingly, the rotor and / or the at least one mixing tool of the premixing device can be operated continuously or intermittently and in particular in both directions of rotation. This allows a particularly good mixing of a wide range of materials.

Expediently, the premixing device has a mixing rotor. According to the invention, this mixing rotor is operated in rotation by the drive for the premixing device, in particular by a rotation axis extending in the mixer center and / or at least approximately vertically. Suitably, the at least one mixing tool is arranged on the mixing rotor.

A further preferred embodiment of the invention consists in that at least one helical mixing tool, preferably two helical mixing tools, are arranged on the mixing rotor. Accordingly, the mixing tool is formed helically. The at least one helical mixing tool can be wound, for example in the form of a right-hand screw. Depending on the direction of rotation, a helical mixing tool can assist the circulation and redeployment of the suspension in the mixing trough or assist in emptying the mixer.

In particular, it may be provided that the at least one helical mixing tool sweeps over a circulation angle between 90 ° and 180 °. Accordingly, the helix covers in the plan view in the direction of the helix axis, which coincides expediently with the axis of rotation of the mixing rotor, an angle between 90 ° and 180 °.

According to the invention it is advantageous if the helical mixing tool follows the inner contour of the mixing trough at a small distance. This can result in a cleaning effect, are stripped in the attachment of solids on the trough inner wall and made available to the mixing process. In particular, a small distance can be understood as meaning that the radial distance of the mixing tool from the inner contour of the mixing trough, relative to the axis of rotation of the mixing tool, is less than 10 mm, in particular less than 5 mm. According to the invention, therefore, the mixing tool can follow the inner contour arcuately at a small distance. The inner contour of the mixing trough may expediently be cylindrical at least in some areas, in particular in the premixing zone, that is to say in the region of the premixing device. As a result, a structurally particularly simple mixer is obtained.

In particular, in order to assist the mixing process in the premixing device, it may be advantageous for the premixing device to have a stirrer mounted rotatably in a stirrer arm. In this case, the stirrer may preferably be mounted eccentrically to the mixer center and / or to the rotor axis of rotation. Due to its rotatable storage in the agitator arm, the stirrer can make its own turn around itself, which particularly supports the mixing process.

As far as a stirrer is provided, it is particularly advantageous that the Rührwerksarm is rotatably connected to the mixing rotor of the premixing device. In this case, the stirrer can not only perform its own rotation about itself, but it is also rotated together with the mixing rotor to the axis of rotation of the mixing rotor usually located in the mixer center, which still supports the effect of the rotor.

Furthermore, it is advantageous that means for actively rotating the stirrer are provided around itself. These means for actively rotating the stirrer may be, for example a further motor, for example an electric or hydraulic motor.

Preferably, it can be provided that the means for actively rotating the stirrer have a traction mechanism drive, wherein the traction means, on the one hand, wraps around the stirrer and, on the other hand, a deflecting wheel arranged non-rotatably on the mixing trough. Such a traction mechanism drive causes the rotation of the Rührwerksarms together with the rotor around the rotor axis of rotation also causes an internal rotation of the stirrer around itself. The deflector wheel non-rotatably mounted on the mixing trough can be mounted, for example, on the mixer lid. In particular, the traction mechanism can be designed as a chain drive, wherein the traction means is then formed as a chain.

A further advantageous embodiment of the invention consists in that the stirrer has at least one replaceable stirring tool. Accordingly, the stirrer is formed with a changing device for different, adapted to the particular application stirring.

Expediently, the rotor of the premixing device has a rotor shaft on which radially projecting arms are arranged. On these arms, on the one hand, the mixing tools and on the other the bearing of the stirrer can be attached.

The invention also relates to a process for the colloidal preparation of a mixture, in which the mixture is introduced into a colloidal mixer according to the invention and is processed to a dispersion.

Fig. 1

ein erstes Ausführungsbeispiel eines Mischers mit separaten Antrieben für Vormischeinrichtung und Dispergiereinrichtung; und

Fig. 2

ein weiteres Ausführungsbeispiel eines Mischers, bei dem ein zusätzlicher Rührer vorgesehen ist.

Hereinafter, embodiments, which are not part of the invention, explained in more detail, which are shown schematically in the accompanying figures. In the figures show:

Fig. 1

a first embodiment of a mixer with separate drives for premixing and dispersing; and

Fig. 2

a further embodiment of a mixer, in which an additional stirrer is provided.

A first embodiment of a mixer is shown in side view in FIG Fig. 1 shown. The mixer shown has a mixing trough 10, in which a premixing zone 11 and below a dispersing zone 12 are formed. In the premixing zone 11, a premixing device 20 is provided for mixing solid, and in the dispersing zone 12 a dispersing device 30 for colloidal digestion.

Both in the premixing zone 11 and in the dispersing zone 12, the mixing trough 10 is approximately cylindrical on both the inside and the outside, with a larger diameter of the mixing trough 10 being present in the upper premixing zone 11 than in the lower dispersing zone 12 On its upper side, the mixing trough 10 has a mixer lid 18, in which feed openings 19 are formed for feeding the starting materials to be mixed. In the dispersing zone 12, the mixing trough 10 on the shell side has an outlet opening 16 for discharging the thoroughly mixed product, to which a discharge hose is arranged in the illustrated embodiment.

The premixing device 20 has a mixing rotor 21 with two mixing tools 23, 23 ', which is mounted rotatably about a rotation axis 80 on the mixing trough 10. In particular, the storage is given at the top of the mixing trough 10 and / or on the mixer cover 18. The mixing rotor 21 has a rotor shaft 24 extending vertically and coaxially to the axis of rotation 80. From this rotor shaft 24 are in the radial direction arms 25 out, on which in turn the mixing tools 23, 23 'are arranged. The two mixing tools 23 and 23 'are helical and follow at a small distance from the inner contour of the premixing zone 11 of the mixing trough 10. They are arranged in an arc and cover in the illustrated embodiment, viewed from above, an angle of about 180 °.

The mixing tools 23, 23 'may for example be wound in the form of a right-hand screw. Runs then the mixing rotor 21 seen from above in a clockwise direction, support shape and rotation of the mixing tools 23, 23 'the circulation and redeployment of the suspension in the mixing trough 10. A reversal of rotation on the rotor causes in this case support the emptying of the mixer, since then the helical mixing tools 23, 23 'have a conveying action in the direction of the dispersing zone 12 and the outlet opening 16 attached here. At the in Fig. 1 illustrated embodiment, however, a left-hand screw of the mixing tools 23, 23 'given, so that the functionality with respect to the direction of rotation is inverse.

The dispersing device 30 has a dispersing rotor 31 with dispersing tools 33. The dispersing tools 33 are designed in the form of plates which extend perpendicularly and radially to the axis of rotation 80. The dispersing rotor 31 is also rotatably mounted about the axis of rotation 80, wherein the storage of the dispersing rotor 31 is provided on the underside of the mixing trough 10.

For the rotary actuation of the mixing rotor 21 of the premixing device 20, a first drive 40 is provided, which is arranged above the mixing trough 10. For the rotary driving of the dispersing rotor 31 of the dispersing device 30, a second drive 50 is provided, which extends partially below the mixing trough 10, and partially laterally next to the mixing trough 10. Since thus the premixing device 20 and the dispersing device 30 have separate drives 40 and 50, the mixing rotor 21 and the dispersing rotor 31 can be operated at different speeds.

The first drive 40 has a first motor 41, which is arranged above the mixing trough 10 in the extension of the rotation axis 80. In the Fig. 1 The drive shaft of the motor 41, not shown for the sake of clarity, runs coaxially with the axis of rotation 80 from the motor 41 to the mixing rotor 21, wherein the mixing rotor 21 is mounted on the front end of the drive shaft of the motor 41. The drive shaft of the first motor 41 is surrounded by a protective tube 49 which extends between the mixing trough 10, namely its mixer cover 18, and the motor 41, and which carries the motor 41. The motor 41 is thus, preferably via the protective tube 49, mounted on the mixer cover 18.

The second drive 50 for the dispersing device 30 has a second motor 51. The drive shaft 52 of the motor 51 is offset from the axis of rotation 80 of the dispersing rotor 31. This offset is made possible by a traction drive 54, which transmits the torque from the motor 51 to the offset dispersing rotor 31. In the illustrated embodiment, the traction mechanism 54 is formed as a belt drive. The traction mechanism drive 54 allows the second motor 51 laterally offset next to provide the mixing trough 10, which allows a particularly space-saving design.

The first drive 40 and / or the second drive 50, in particular their motors 41 and 51, are preferably designed such that the premixing device 20 or the dispersing device 30 can be operated in both directions of rotation.

Another embodiment of a mixer is shown in FIG Fig. 2 shown. The embodiment of Fig. 2 differs from the embodiment of Fig. 1 essentially in that according to Fig. 2 the premixer 20 has an additional stirrer 60. The remaining elements of the embodiment of the Fig. 2 are essentially identical to the embodiment of the Fig. 1 trained so that these elements will not be discussed again in detail at this point.

In the embodiment of Fig. 2 For example, the agitator 60 is shown together with the helical mixing tools 23, 23 '. In principle, however, the stirrer 60 can be used in mixers which do not have helical mixing tools 23, 23 ', just as helical mixing tools 23, 23' can also be realized without stirrer 60.

The stirrer 60 is arranged eccentrically to the mixer center and to the rotation axis 80. It is mounted on a Rührwerksarm 26 which is rotatably connected to the rotor shaft 24 of the mixing rotor 21 and extending from the rotor shaft 24 radially outward. Since the agitator arm 26 and consequently also the agitator 60 are thus connected in a rotationally fixed manner to the mixing rotor 21, the first drive 40 also causes the agitator arm 26 and the agitator 60 to rotate. During this rotation, the agitator 60 rotates around the axis of rotation 80. The agitator 60 can be equipped with different agitating tools 61 adapted to the respective application, wherein a U-shaped agitating tool 61 is provided in the illustrated embodiment.

In principle, it may be sufficient to provide the agitator 60 without active drive, that is to say the agitating tool 61 is freely rotatable about itself. For the rotation of the agitator arm 26 with the stirrer 60 about the axis of rotation 80 may already be sufficient for a correspondingly formed stirrer 60 to a Rotation of the stirring tool 61 to induce itself. This rotation about itself can effectively assist in the incorporation of additional solids in highly viscous suspensions.

This effect can be enhanced by an active drive of the agitator 60, in which means are provided for actively rotating the agitator 60 around itself. These means for actively rotating the agitator 60 around itself may comprise, for example, a stand-alone motor. In the illustrated embodiment, however, the active drive is formed by a traction mechanism, which is a particularly simple design.

The traction mechanism drive has a first deflection wheel 68 which is non-rotatably arranged on the mixing trough 10, namely its mixer cover 18, and a second deflection wheel 69, which is non-rotatably connected to the stirrer 60, in particular to the stirring tool 61. The two deflection wheels 68, 69 are both looped by a traction means 67, so that rotation of the mixing rotor 21 and thus of the agitator arm 26 about the axis of rotation 80 causes the agitating tool 61 to rotate about itself.

The said traction mechanism drive is formed in the illustrated embodiment as a chain drive, that is, in the two deflecting wheels 68, 69 are sprockets and the traction means 67 to a chain. For example, the first guide wheel 68, which is arranged on the mixing trough 10, be designed as a large wheel, and the second guide wheel 68 as a small wheel, so that a speed ratio is given to the agitator 60 out. The speed of the stirrer 60 in relation to the speed of the mixing rotor 21 can be influenced by the choice of the translation of the traction mechanism.

Claims (12)

1. Colloidal mixer, in particular for preparing building materials, with

   - a mixing trough (10), in which a premixing means (20) and a dispersion means (30) are arranged, and

   - drive means (40, 50) for actuating the premixing means (20) and the dispersion means (30),

   - wherein the premixing means (20) has a mixing tool (23) and the dispersion means (30) has a dispersion tool (33),

   - wherein the mixing tool (23) and the dispersion tool (33) are driven about a common axis of rotation (80),

   - wherein in the mixing trough (10) the premixing means (20) is arranged in a premixing zone (11) and the dispersion means (30) in a dispersion zone (12) formed below the premixing zone (11),

   - wherein the premixing zone (11) and the dispersion zone (12) of the mixing trough (10) are of approximately cylindrical design both on the internal and external side, wherein the premixing zone (11) has a greater diameter than the dispersion zone (12) lying underneath, and

   - wherein in the dispersion zone (12) the mixing trough (10) has on the casing side an outlet opening (16) for discharging the mixed product,

   - wherein the premixing means (20) and the dispersion means (30) are rotationally decoupled,

   - wherein for an independent driving of premixing means (20) and dispersion means (30) two separate drives (40, 50) are arranged, wherein one drive (40) is provided for the premixing means (20) for driving the mixing tool (23) in a rotating manner and a second drive (50) is provided for the dispersion means (30) for driving the dispersion tool (33) in a rotating manner,

   characterized in that

   - the drive (40) for the premixing means (20) has a hollow shaft, through which a drive shaft of the drive (50) for the dispersion means (30) is guided.
2. Colloidal mixer according to claim 1,
   characterized in that
   the drive (50) for the dispersion means (30) is arranged at least partially below the dispersion means (30) and
   in that the drive (40) for the premixing means (20) is arranged at least partially above the premixing means (20).
3. Colloidal mixer according to any one of the preceding claims,
   characterized in that
   the drive (40) for the premixing means (20) is adapted for a continuous operation or for an intermittent operation of the premixing means (20), preferably in both directions of rotation.
4. Colloidal mixer according to any one of the preceding claims,
   characterized in that
   the premixing means (20) has a mixing rotor (21), on which at least one helical mixing tool (23), preferably two helical mixing tools are arranged.
5. Colloidal mixer according to claim 4,
   characterized in that
   the at least one helical mixing tool (23) moves through an angle of rotation between 90° and 180°.
6. Colloidal mixer according to claim 4 or 5,
   characterized in that
   the helical mixing tool (23) follows the inner contour of the mixing trough (10) at a short distance.
7. Colloidal mixer according to any one of the preceding claims,
   characterized in that
   the premixing means (20) has an agitator (60) supported in a rotatable manner in an agitator arm (26).
8. Colloidal mixer according to claim 7,
   characterized in that
   the agitator arm (26) is connected in a torque-proof manner to the mixing rotor (21) of the premixing means (20).
9. Colloidal mixer according to claim 7 or 8,
   characterized in that
   means for actively rotating the agitator (60) about itself are provided.
10. Colloidal mixer according to claim 9,
    characterized in that
    the means for actively rotating the agitator (60) have a traction-means drive, in particular a chain drive, wherein the traction means (67) wraps on the one hand around the agitator (60) and on the other hand around a deflection wheel (68) arranged in a torque-proof manner on the mixing trough (10).
11. Colloidal mixer according to any one of claims 7 to 10,
    characterized in that
    the agitator (60) has at least one exchangeable agitating tool (61).
12. Method for the colloidal preparation of a mixture, in particular for preparing building materials, with a colloidal mixer according to any one of claims 1 to 11,
    wherein the mixing tool (23) is driven independently of the dispersion tool (33) about the common axis of rotation (80) and
    the mixed product is discharged through the outlet opening (16) located on the casing side in the mixing trough (10) in the dispersion zone (12).

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