EP3702023B1 - Inclined mixer - Google Patents

Description

The present invention relates to an inclined mixer which is used, for example, to mix building materials, in particular for the production of cement emulsions, foam concrete, color mixes and styrofoam concrete. Said mixer is preferably used for the production of high-quality concrete materials such as self-compacting concretes, ultra-high-strength concretes, mineral cast and all other types of concrete. Such a mixer has an inclined mixing container and can be used, for example, in concrete and chemical plants, but also in the food and feed industries. Such a mixer is preferably designed as a single-shaft mixer.

For building materials in particular, it is important to be able to produce materials with properties that are as homogeneous as possible in order to avoid local differences in concentration, inhomogeneities and clumping, which can lead to poor concrete quality. This in turn could lead to defects and damage to structures.

Furthermore, for economic reasons it is important that the time in which a concrete mix is mixed is kept as short as possible so that it can be used quickly on the construction site. Furthermore, the lowest possible energy consumption is also advantageous.

Various mixers are known in the prior art which can be used, among other things, for mixing building materials.

From the document DE 36 04 333 A1 a single-shaft compulsory mixer is known in which the mixing container can be tilted depending on the mixing task. By changing the inclination and / or changing the speed, an adaptation to different mixing processes can be realized very economically. For particularly difficult mixes with a constant axle position, bottom emptying in conjunction with a reversal of the direction of rotation is provided.

document DE 11 82 036 B discloses a mixer with two shafts that rotate in opposite directions of rotation. Blades are attached to both shafts.

The prior art is from the document DE 3604333 A1 a single-shaft compulsory mixer is known, which is inclined by about 45 degrees from the horizontal during the mixing process. This mixer can be tilted further or in two directions for emptying, so that all the material to be mixed can flow out of the mixer and can thus be removed by gravity. Various mixing tools are disclosed for this mixer, for example a screw-shaped mixing tool and mixer blades. In this mixer, the actual mixing is only disclosed in one direction, but the direction of rotation of the mixing tool can also be reversed for emptying the mixing container. This prior art mixer is suitable for a variety of solids.

It is therefore the object of the present invention to provide a mixing apparatus with improved mixing intensity and improved mixing properties and cleaning properties, which can be built as simply and inexpensively as possible, and in which the mixing time can be kept as short as possible.

This object is achieved by a mixer according to claim 1 and by a method according to claim 8 and a use according to claims 9, 10.

Further advantageous refinements of the invention are the subject matter of the dependent claims.

The invention includes a mixer with a mixing container which is inclined with respect to the horizontal. The angle of inclination is preferably 10 ° to 80 °, preferably 15 ° to 70 °, more preferably 30 ° to 60 °.

Furthermore, the drive that drives the mixing tool can be operated in two opposite directions, so that it is possible to switch between two directions of rotation of the mixing mechanism. This mixer is also preferably designed as a single-shaft mixer. Such a configuration of the mixer enables shorter mixing times for all types of concrete compared to the prior art, but at the same time the achievement of homogeneous mixtures. This is achieved in particular by the fact that the entire material to be mixed is in motion during the mixing process, since it is pressed by gravitational forces to the lowest point of the mixing container, where it is moved periodically by a mixing tool. By changing the direction of rotation, the entire material is moved more often and the mixing effect is additionally reinforced, since the material is conveyed to the lower wall in one direction of rotation, but is conveyed back to the actual mixing devices in the other direction of rotation, among other things by scrapers . Thus, the cross transport of the mixed material takes place due to the inclined position of the mixing container and the opposing operation of the mixing tool. This allows cement to be saved, for example due to the improved opening. In the manufacture of prefabricated parts, in which color is added to cement, the color is opened up considerably better than in prior art mixers. In addition, even with media with a large difference in density (for example Styrofoam balls in concrete), a significantly faster and better mixing is possible. A real mixing effect is achieved in both directions of rotation.

The mixing tool comprises a centrally arranged axis and at least one mixing device attached to it, which is preferably also provided with branches. At the end of the mixing device, a scraper is arranged, which is adapted to rest with one side on the inside of the jacket of the mixing container and to brush it in one direction of rotation. This scraper also has the function of a mixing tool. The direction of extension of the scrapers is rotated around the direction of the central shaft by an angle which is 10 ° to 80 °, more preferably 15 ° to 70 ° and even more preferably 30 ° to 60 °. This allows a particularly advantageous mixing and scraping action of the scrapers, since the scrapers can convey or move mixed material in the direction in which the central shaft extends. The transverse transport of the mix is thus significantly improved.

More preferably, a mixing device can additionally have a lance which is retractable through an opening into the interior of the mixing container. Such a lance is connected at one end to a vibration motor and at the other end can be in contact with the mixing tool in order to transmit the vibrations of the vibration motor to this, which allows better cleaning. Especially in the case of mixing tools with a large surface, which is the case according to the invention due to branches and scrapers, this is very advantageous for cleaning.

Furthermore, in one embodiment, in particular on the lower area, for example the base plate of the mixing container, nozzles can be provided through which a fluid, for example air, can be introduced. This allows better mixing through stronger turbulence of the material to be mixed. Furthermore, such nozzles allow an improved and faster cleaning of the mixer after use.

The mixing apparatus preferably also has a frequency converter which is connected to the drive of the mixing tool and controls its power consumption.

If the mixing container is fully loaded with material and the mixing tool is to change the direction of rotation, the force that the drive must apply to start mixing in the changed direction is very high for a short time. The frequency converter prevents the drive from consuming too much power when it starts up. This relieves the load on the drive and therefore has a longer service life. This means that even difficult start-up conditions can be operated without strong overcurrent peaks. Without a frequency converter it would not be possible to change the direction of rotation of the mixing tool when the mixing container is full, or the drive would have to be very large in order to obtain the required power - the power consumption would also increase drastically. Furthermore, without the frequency converter, rapid wear and tear of the drive's gearbox would have to be expected.

The frequency converter also ensures that the actual torque of the drive can be regulated between the lowest possible torque (i.e. zero) and the highest possible torque of the drive, which is particularly advantageous when changing the direction of rotation and thus the mixing direction. Targeted control of the drive torque is therefore possible.

Using a frequency converter also has the advantage that electricity can be saved. Such a frequency converter is also officially subsidized by the state.

In a further embodiment, one or more agitators can also be provided in the mixing apparatus. These whirlers are additional structures on the mixer, which contain a drive, a whirling shaft and at least one whirling tool.

A swirler is arranged on the mixer in such a way that it does not touch the central shaft or the mixing tools and cannot interfere with them.

A whirler is particularly advantageous when the material is very difficult to mix.

Such a vortex can increase the mixing effect of the mixing apparatus by creating a cross flow.

In addition, better mixing of the material to be mixed can be achieved, lumps in the material to be mixed can be destroyed and the material breakdown can be improved.

This further embodiment can have at least one, preferably several additional vortices.

Fig. 1

zeigt eine Querschnittansicht eines Mischapparats gemäß einer ersten Ausführungsform der vorliegenden Erfindung.

Fig. 2

zeigt eine Schnittansicht A-A aus Fig. 1.

Fig. 3

zeigt eine weitere Schnittansicht entlang der Linie B-B aus Fig. 1.

Fig. 4

zeigt einen Mischapparat gemäß der ersten Ausführungsform der vorliegenden Erfindung, wobei hier allerdings ein Teil des Mantels weggelassen ist, so dass das Innere des Mischbehälters sichtbar ist, insbesondere das Mischwerkzeug.

Fig. 5

zeigt eine Ansicht von schräg unten auf den Mischbehälter der ersten Ausführungsform.

Fig. 6

zeigt eine isometrische Ansicht einer weiteren Ausführungsform des Mischapparats, welche ferner einen Wirbler aufweist.

Fig. 7

zeigt eine Querschnittansicht des Mischapparats der weiteren Ausführungsform wie in Fig. 6 dargestellt, wobei hier zwei Wirbler vorgesehen sind.

In the following, preferred exemplary embodiments are explained in more detail with reference to the accompanying drawings.

Fig. 1

Fig. 13 is a cross-sectional view of a mixing apparatus according to a first embodiment of the present invention.

Fig. 2

shows a sectional view AA from Fig. 1 .

Fig. 3

FIG. 11 shows a further sectional view along the line BB from FIG Fig. 1 .

Fig. 4

shows a mixing apparatus according to the first embodiment of the present invention, but here a part of the jacket is omitted so that the interior of the mixing container is visible, in particular the mixing tool.

Fig. 5

shows a view obliquely from below of the mixing container of the first embodiment.

Fig. 6

Figure 12 shows an isometric view of another embodiment of the mixing apparatus which further includes a swirler.

Fig. 7

FIG. 13 shows a cross-sectional view of the mixing apparatus of the further embodiment as in FIG Fig. 6 shown, with two vortices being provided here.

the end Fig. 1 it can be seen that in the mixing apparatus 1 according to the present embodiment, the cylindrical mixing container 2 is inclined at an angle α to the horizontal. In the present embodiment, this angle α is approximately 45 °. In this embodiment, the mixing container 2 has both a casing 2a and a base plate 2b. A mixing tool 3 is provided in the middle of the mixing container. This mixing tool 3 has a central shaft 3 a, to which mixing devices 3 b are attached via connecting devices 3 d and which extend from the central shaft 3 a in the direction of the casing 2 a of the mixing container 2. The mixing devices 3b are branched, and a plurality of branches 3c are arranged on the mixing devices 3b. A scraper 5 is arranged at the end of the mixing devices 3b, one side of which rests against the inner wall of the casing 2a of the mixing container 2. The mixing tool 3 a is driven by a drive 4 which is mounted outside the mixing container 2 and which is connected to a frequency converter 12.

Furthermore, an opening 6a (not shown here) is provided in the jacket 2a of the mixing container 2, which opening is provided with a closure means 6a. A lance 7, which is adapted to be able to be advanced up to the central shaft 3a and to be in contact with it, can be inserted through this opening. At the other end of the lance 7, i.e. outside of the mixing container 2, a vibration motor 8 is attached to the lance, which can transmit vibrations to the lance 7 and thus also to the mixing tool 3, so that it can be used after the The mixer is easier to clean. Furthermore, a lower scraper 11 is provided at the lower end of the middle shaft 3a, which sweeps over the bottom plate 2b from the inside in order to clean it if necessary.

Fig. 2 FIG. 11 shows a sectional view along the line AA from FIG Fig. 1 . Here, so to speak, a glimpse into the interior of the mixing container 2 is possible. the end Fig. 2 it becomes clear that a plurality of mixing devices 3b are arranged on the central shaft 3a in this embodiment, two of these mixing devices 3b enclosing an angle β here. It can also be seen that a scraper 5 is arranged at the end of each of the mixing devices 3b and rests against the inner wall of the jacket 2a.

Fig. 3 FIG. 13 shows a cross-sectional view along the line BB in FIG Fig. 1 . Here it becomes particularly clear how the scrapers 5 are arranged on the mixing devices 3b. The direction of extension of the scrapers 5 is rotated around the direction of the central shaft 3a by an angle γ. This angle γ is approx. 45 ° here. It can also be seen from this view that nozzles 9 are arranged on the bottom 2b of the mixing container 2. These are used to introduce a fluid, for example air, to improve the mixing effect and for cleaning purposes.

Fig. 4 shows a view similar to that in Fig. 1 except that a part of the casing 2a is not shown here, so that, so to speak, a view into the interior of the mixing container 2 is possible. The drive 4, the frequency converter 12, the base plate 2b, the lance 7 and the vibration motor 8 are the same as in FIG Fig. 1 . However, the exact arrangement of the mixer 3 becomes clear here: Several mixing devices 3b are arranged on the central shaft 3a, on which the branches 3c and the scrapers 5 are in turn arranged. Here, too, it is again made clear that the scraper 5 is not arranged parallel to the central shaft 3a, but rotated relative to it (by the angle γ). This results in the following effects: When operating in the forward direction (V), the scrapers 5 move the material to be mixed towards the ground and thereby press it to the lowest point of the mixing container 2. This further enhances the mixing effect, as the material is first pressed downwards Secondly, however, it is also conveyed back through the scraper 5 in the direction of the central shaft 3a and thus to the mixing devices 3b and branches 3c. The downward pressure in the mix depends on the angle γ (see Fig. 4 ) away, around which the scrapers 5 are rotated relative to the central shaft 3a. When operating in the reverse direction (R), the material to be mixed is conveyed obliquely upwards and the inner wall of the container jacket 2a is stripped off so that any parts of the material to be mixed which may adhere to it are conveyed back into the interior of the mixing container 2. The frequency converter 12 also allows a simple and energy-saving change in the direction of rotation.

Fig. 5 Fig. 13 shows a mixing apparatus of the present embodiment from below. The arrangement of the outlet opening 10 in the base plate 2b of the mixing container 2 is particularly evident here. The arrangement of the nozzles 9 in the base plate 2b of the mixing container 2 is also clear here.

By selecting special angles α, β and γ, the mixing device can be adapted to a particular mixing task, ie the mixing container 2 can be inclined at a very specific angle α around the horizontal, the mixing devices 3b can be arranged at a specific angle β from one another, and the angle γ by which the scrapers 5 are rotated about the direction of the central shaft 3a can also vary.

The angle β between two mixing devices 3b can, for example, preferably be 10 ° to 180 °, more preferably 40 ° to 90 °, even more preferably 45 ° to 60 °.

Fig. 6 Figure 3 shows an isometric view of another embodiment of the present invention. The mixing apparatus 1 also has a vortex 13 on the jacket 2a, of which the drive 13a and the vortex shaft 13b are shown here. This agitator 13 is preferably arranged vertically on the lateral surface 2a and protrudes into the mixing container 2, the agitator 13 being arranged at those points at which no mixing tool 3 is provided on the centrally arranged shaft (3a). The swirler 13 is fixed here on the jacket 2a. In Fig. 6 the drive 4, the frequency converter 12, the casing 2a and the base plate 2b are the same as in the first embodiment.

In Fig. 7 Figure 3 shows a cross-sectional view of the further embodiment of the mixing apparatus according to the present invention. Here two vortexes are arranged in the mixing apparatus 1, each with a drive 13a and a vortex shaft 13b, the vortex tools 13c also being shown here. These are flat and plate-like and are attached to the vortex shaft 13b. Furthermore, these whirling tools 13c are arranged in such a way that they are at a distance from the centrally arranged shaft 3a.

Furthermore, the two drives 13a are each connected to a vortex frequency converter 13d so that these vortexes can also be driven in both directions and can have the same advantages as the drive 4 for the entire mixer (not shown here).

FURTHER EMBODIMENTS

It is not absolutely necessary for the mixing container 2 to have a cylindrical shape. Rather, conical or frustoconical shapes can also be possible here. The number of mixing devices 3b which is attached to an inner shaft 3a can also vary depending on the mixing task.

Furthermore, a plurality of different mixing devices 3b can be attached to the inner shaft 3a.

Furthermore, the angles γ on the scrapers 5 on the individual mixing devices 3b can be different, so they do not have to be the same on each of the individual mixing devices 3b. Furthermore, different types of branches 3c can be present in a plurality of mixing devices 3b. These can extend from the mixing devices 3b in all spatial directions.

A method for mixing a material to be mixed in a mixing apparatus 1 according to the present invention will be described below. Here, the mixing container 2 is first charged with the components to be mixed. The mixing tool 3 is then rotated in one direction. After a certain period of time, the direction of rotation of the mixing tool 3 is changed. In one direction, the material is pressed into the lower wall and additionally conveyed with the scraper 5 back in the direction of the inner shaft 3a, while in the other operating direction mainly the wipers 5 fulfill the function of cleaning the inside of the container 2. The scrapers 5 thus also perform the function of a mixer blade in addition to the scraping effect.

After changing direction, the mix is conveyed in the opposite direction. Depending on the mix, the direction of rotation of the mixing tool 3 is changed several times per mixing process.

A fluid, preferably air, is preferably also blown in through the at least one nozzle 9 during one or more of the above-mentioned operating phases

When the mixing process is complete, the rotation of the mixing tool is stopped.

For cleaning and draining, the procedure is expanded to include the following steps:
The outlet opening 10 is opened so that the mixed material can flow out of the mixing container 2. By moving in two different directions, the lower scraper 11 can free the entire inner part of the base plate 2b from the material to be mixed and convey it through the outlet opening 12 from the mixing container until the mixing container 2 is empty. Optionally, the lance 7 can then be moved into the mixing container 2 until one end of the lance 7 is in contact with the mixing tool 3, for example with the central shaft 3a.

The vibration motor is then switched on so that the mixing tool 3 is freed from the material to be mixed.

After all the mixed material has run out of the mixing container 2, water can be introduced into the mixing container 2 through the at least one nozzle 9 in order to clean it further.

The present invention concerns a mixer 1 which is used, for example, for mixing concrete materials. Here, the mixing container 2 is inclined with respect to the horizontal and the drive 4, which drives the mixing tool 3, can be operated in two opposite directions. This serves to improve the mixing properties and to shorten the mixing time.

Claims (10)

1. Mixing apparatus (1), comprising:

   a mixing container (2) comprising a shell (2a) and a bottom plate (2b),

   a mixing tool (3) which is rotatably provided in the mixing container (2),

   a drive (4) which drives the mixing tool (3),

   wherein the mixing container (2) is inclined with respect to the horizontal,

   and wherein the drive (4) which drives the mixing tool (3) is adapted to be operated in two opposite directions for mixing, wherein the mixing apparatus (1) is designed as a single-shaft mixer,

   wherein the mixing tool (3) comprises a shaft (3a) centrally arranged in the mixing container (2), as well as at least one mixing device (3b) attached thereto, which extends from the centrally arranged shaft (3a) towards the shell (2a) of the mixing container (2), wherein at the end of the mixing device (3b) facing away from the centrally arranged shaft (3a) a scraper (5) is arranged, which is adapted to abut with one side against the inside of the shell (2a) of the mixing container (2),

   wherein the scraper (5) is twisted by an angle (γ) of 10°-80° with respect to the direction of extension of the inner shaft (3a).
2. Mixing apparatus (1) according to claim 1, wherein the angle of inclination of the mixing container (2) to the horizontal is adjustable in a range of 30° to 80°, preferably 15° to 70°, further preferably 30° to 60°.
3. Mixing apparatus (1) according to any one of the preceding claims,
   wherein the mixing device (3b) has branches (3c).
4. Mixing apparatus (1) according to claim 3,
   wherein the scraper (5) is twisted with respect to the direction of extension of the inner shaft (3a) by an angle (γ) which is 15°-70°, further preferably 30° to 60°.
5. Mixing apparatus (1) according to claim 3 or 4, wherein a plurality of mixing devices (3b) are arranged on the centrally arranged shaft (3a) via fastening devices (3d), wherein the angle (β) enclosed by two of the plurality of mixing devices (3b) is variable in an adjustment mode but fixable in a mixing mode.
6. Mixing apparatus (1) according to any one of the preceding claims, wherein an outlet opening (10) is provided on the bottom plate (2b) of the mixing container (2), wherein the outlet opening (10) is preferably closable by a closing means (10).
7. mixing apparatus (1) according to any one of the preceding claims, further comprising a frequency converter (12) connected to and supplying power to the drive (4).
8. Method of mixing a plurality of components with a mixing apparatus (1) according to any one of the preceding claims, comprising the steps of:

   - Filling the mixing container (2) with the components to be mixed,

   - Rotation of the mixing tool (3) in one direction,

   - Changing the direction of rotation of the mixing tool (3),

   - Stop the rotation of the mixing tool (3).
9. Use of a mixing apparatus (1) according to any one of claims 1 - 7 for the production of concrete.
10. Use of a mixing apparatus (1) according to any one of claims 1 - 7 for the production of cement emulsions, foamed concrete, colour mixtures and polystyrene concrete as well as high-quality concrete materials such as self-compacting concretes, ultra-high-strength concretes and mineral casting.

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