EP2092975B1 - Mixing device with a mixing bowl fixed to a mix container - Google Patents

Abstract

The device has a mixing bowl (1) attached to an inner wall of a mixing tank. A rotor (8) with rotor arms (10) is rotated around an axis (9) that is aligned to an interior of the mixing tank in the bowl. The arms coat a radially defined area that includes a whole depth (6) of the bowl. A knife pulverizing a mixture is arranged in an axially parallel running, radially inner-lying area of the bowl. The arms are engaged with radially extending cutting blades. The arms comb with stator teeth protruding radially from a mixing bowl wall. A supply opening (25) is arranged at the mixing bowl wall.

Description

The invention relates to a mixing device with a mixing container in which a mixing tool is gebart, which sweeps over the wall of the mixing container, wherein on the said wall outside an open to the interior of the mixing container, a depth having mixing pot is mounted, in which a rotor with rotor arms, the having a Mischgut auswerfende effect to rotate a directed towards the interior of the mixing container axis without the rotor arms approached from the mixing pot.

The mixing container for such a mixing device may preferably be a substantially horizontally oriented mixing trough. However, a corresponding mixing container can also be aligned substantially vertically with its center axis.

In the mixing container can be installed pneumatically operated mixer or known mixing tools plowshare mixer, paddle mixer, screw conveyor, conical screw mixer, either with a central screw or with on the container wall by a rotating arm along guided screw, which rotates around itself, etc.

The mixing device described herein may be used to mix products together or to increase the mixing intensity, or to achieve a comminution value. In this case, the mixing device described works like a conventional mill. This is understood in the context of the present invention as interchangeable.

Thus, such a mixing device can also be used to prevent the formation of too large particles in mixing, drying or reaction processes or to produce emulsions or dispersions as well as for the dissolution of solids in liquids etc.

In such mixing devices, it is from the DE 1 184 325 discloses a device according to the preamble of claim 1 disclosed to flare a mixing pot outside of the mixing vessel wall. In this case, a plurality of knife rings arranged essentially parallel to one another rotate in this known mixing pot about an axis directed towards the interior of the mixing container. The knife ring closest to the mixing container is intended to have a gradient sucking up the mix present in the mixing container, while the knife ring, which is arranged at the end of the mixing pot which faces away from the mixing container, has a tendency to eject the mix from the mixing pot. In between a third ring of knives should be provided, which has no slope.

In practical use, these known mixing bowls with knurled rings have not been successful: The produced by the individual kneading inflating and ejecting effects ultimately cancel each other, so that neither within these known mixing pots a sufficient material exchange is still taken to a considerable extent mix from the mixing container and is processed in the mixing pot. The desired improvement in the mixing effect of appropriately designed mixing devices does not arise.

It was therefore about to move appropriate attached to the wall of mixing vessels mixing rotors inside the mixing vessels, as for example in the EP 0 740 953 is disclosed. However, such mixing rotors installed in the interior of a mixing container have the disadvantage that the container wall of the mixing container in the region of such mixing rotors can not be swept by the mixing tools of the mixing apparatus. This can lead to product deposits. These non-swept areas also have disadvantages in the emptying, especially of horizontal mixing devices, as there are considerable residual amounts of products can lag behind, which can cause problems with a follow-up batch.

The drive shafts of such rotors placed in the interior of a mixing container are heavily strained for bending by product portions which are passed past them and in some cases compressed by the mixing tools of the mixing apparatus. The drive shafts must therefore be designed for a corresponding bending stress, so that they are thicker than in a pure torsional load. This in turn leads to an enlargement of not painted by mixing tools areas of Mischbehälterwandung.

So that the drive shafts are not too large, the corresponding rotors can not be chosen arbitrarily large. It is therefore used in larger mixing devices instead of a large rotor or a few large rotors many smaller rotors. But this also leads to an increased number of engines, many expensive seals for the implementation of drive shafts through the mixing tank wall and also to a high installation costs associated with it.

In addition, such misplaced in the interior of a mixing vessel rotors in unfavorable constellations, in which foreign bodies enter a mixing device, collide with these and the mixing tools, which can lead to the destruction of the rotors.

In all these aspects, it makes sense to accommodate the rotors in a mixing pot mounted outside the wall of the mixing vessel.

However, it raises the task of overcoming the above-described disadvantages of the known device with a mixing pot fixed on the outside of the wall of a mixing container so that a desired improvement of the mixing process is achieved with a mixing pot arranged outside this way.

This object is achieved in that the rotor arms of a rotor arranged in the mixing pot with respect to the rotational direction of the rotor are inclined backwards and sweep only a radially limited, but substantially the entire depth of the mixing pot comprehensive range.

The invention is based on the finding that in the from the DE 1 184 325 Known device the knife rings over the entire clear width of the mixing pot Mischgut in the mixing pot hineinfördert or have conveyed out of this at the bottom of the mixing pot again.

In contrast, in the development of the device according to the invention, a mixed material flow directed into the interior of the mixing container is produced only in an annular region of the clear width of the mixing pot. This flow bridges the entire depth of the mixing pot. At the same time a suction of mixing material to the bottom of the mixing pot is generated by the annular flow in the opposite direction in the not swept by the rotor arms areas. Thus, a continuous exchange of mix is achieved in the mixing pot.

In a particularly preferred embodiment, the swept over by the rotor arms annular region can be found radially outwardly in the mixing pot. Thus, due to the radially inner or central region, mixed material reaches the bottom of the mixing pot, where it meets the rotating rotor arms and is pressed outwards by the centrifugal force, and then again in the radially outer annular regions of the mixing pot to be guided or pressed to the interior of the mixing container. This builds on a particularly reliable way a continuously functioning flow that leads mix from the mixing tank through the mixing pot back into the mixing vessel.

It is within the scope of the invention to direct the mix in the axially parallel, radially inward region of the mixing pot already on a knife comminuting the mix, which can be arranged there. This knife can, in order to support the axis-parallel central flow, also be designed to be absorbent.

It is further within the scope of the invention if the rotor arms arranged downstream of these knives are then provided exclusively for producing a radially outer ejection flow for the mix.

But it is also possible to occupy these rotor arms themselves with corresponding cutting blades, which then extend substantially radially. In such embodiments can be dispensed with a knife arranged in the radially inner region. The shredding function of this knife is taken over by the cutting blades.

The cutting blades can be mounted both radially inward and radially outward on the rotor arms.

It is also within the scope of the invention to mount the cutting blades on different rotor arms of the same rotor inside or outside.

In another embodiment of the invention, in which the mix is to be subjected to sheared shear and thus crushing, the rotor arms mesh to form Mahlspalten with radially projecting from the mixing pot wall stator teeth. By means of the shear which occurs, a high energy can be introduced into the mix, as a result of which special desired properties can be achieved in the finished mix.

Again, it is possible from a design point of view, in addition to rotor arms, which have only one ejection effect, provide separate rotor arms, which form corresponding Mahlspalte with protruding from the mixing pot wall stator teeth. As a result, mix can be alternately promoted, sheared, promoted, etc.

In order to be able to add fluids to powder or pasteusem material, the mixing bowls provided are particularly suitable since they can be provided with a corresponding feed opening for the liquid addition. Thus, an intensive mixing of the liquid is ensured with mix within the mixing pot. Preferably, such a feed opening be arranged the wall of the mixing pot, since in particular in rotor / stator designs in zones of high shear, a particularly intensive mixing of liquid can be achieved.

In a further preferred embodiment of the invention, however, a corresponding mixing pot can also be provided with a closable discharge opening for the mixing device. This discharge opening can be relatively easily realized in such a mixing pot constructively, for example, on the wall of the mixing pot. It is easily possible with a device according to the invention to rotate the drive motor for a rotor in a direction opposite to the usual directions of work in the mixing pot in order to promote Mischgut from the mixing container.

Figur 1

einen Schnitt durch einen Mischtopf mit einem Rotor, dessen Rotor- arme mit Statorzähnen kämmen als Prinzipdarstellung;

Figur 2

einen Schnitt durch einen Mischtopf mit einem um 90° gedrehten Rotor gemäß Figur 1 als Prinzipdarstellung;

Figur 3

eine Schnittansicht durch einen Rotorarm gemäß der Linie III/III in Figur 1;

Figur 4

eine Schnittansicht durch einen Rotorarm gemäß der Linie IV/IV in Figur 2;

Figur 5

eine Aufsicht auf einen Mischtopf gemäß den Figuren 1 und 2 mit Rotorarmen, die mit Statorzähnen kämmen;

Figur 6

einen Schnitt durch einen Mischtopf mit im radial innenliegenden Bereich angeordnetem Messer als Prinzipdarstellung;

Figur 7

eine Schnittansicht durch einen Rotorarm gemäß der Linie VII/VII in Figur 6;

Figur 8

eine Aufsicht auf einen Mischtopf gemäß Figur 6;

Figur 9

eine Darstellung eines Rotors mit innenliegenden Schneidflügeln an den Rotorarmen;

Figur 10

eine Darstellung eines Rotors mit innen- und außenliegenden Schneidflügeln an den Rotorarmen;

Figur 11

eine Darstellung eines weiteren Rotors mit einzelnen an Rotorarmen außenliegenden Schneidflügeln;

Figur 12

eine Außenansicht eines Mischbehälters mit mehreren außen daran angebrachten Mischtöpfen;

Figur 13

eine Axialansicht eines Mischbehälters gemäß Figur 12;

Figur 14

eine Einzelansicht eines Mischtopfes gemäß der Einzelheit XIV in Figur 13.

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

FIG. 1

a section through a mixing pot with a rotor whose rotor arms with stator teeth mesh as a schematic diagram;

FIG. 2

a section through a mixing pot with a 90 ° rotated rotor according to FIG. 1 as a schematic diagram;

FIG. 3

a sectional view through a rotor arm along the line III / III in FIG. 1 ;

FIG. 4

a sectional view through a rotor arm according to the line IV / IV in FIG. 2 ;

FIG. 5

a view of a mixing pot according to the Figures 1 and 2 with rotor arms that mesh with stator teeth;

FIG. 6

a section through a mixing pot with arranged in the radially inner region knife as a schematic representation;

FIG. 7

a sectional view through a rotor arm according to the line VII / VII in FIG. 6 ;

FIG. 8

a view of a mixing pot according to FIG. 6 ;

FIG. 9

a representation of a rotor with internal cutting blades on the rotor arms;

FIG. 10

a representation of a rotor with inner and outer cutting blades on the rotor arms;

FIG. 11

a representation of another rotor with individual on rotor arms outer cutting blades;

FIG. 12

an external view of a mixing container with a plurality of mixing pots attached to the outside;

FIG. 13

an axial view of a mixing container according to FIG. 12 ;

FIG. 14

a single view of a mixing pot according to the detail XIV in FIG. 13 ,

In FIG. 1 recognizes the sectional view through a mixing pot 1 as a schematic diagram. This mixing pot is attached via a flange 2 to the container wall 3 of a mixing container.

The flange 2 of the mixing pot 1 is attached to a flange collar 5, via which the interior of the mixing pot 1 opens to the interior of the mixing container. The height of the mixing pot 1 and the height of the flange collar 5 total of the depth 6 of the mixing pot.

By circulating on the container wall channels 4, the mixing pot 1 can be heated or cooled and thus the mixture in the mixing pot 1 heat supplied or withdrawn.

At the bottom of the mixing pot 1, a shaft 7 is provided which carries a rotor 8 at its end located within the mixing pot 1 end. About the shaft 7, the rotor 8 can be rotated about the axis 9, which is directed to the interior of the mixing container.

The rotor 8 carries at its radially outer ends rotor arms 10, which have in the axial extent substantially a length corresponding to the depth 6 of the mixing pot. The mixing vessel facing ends of the rotor arms 10 are within the mixing pot 1. During a rotation of the rotor arms 10 so they can not collide with a mixing tool that touches within the mixing container on the container wall 3.

It is essential that the swept radial range of the rotor arms is limited radially, so that when rotating the rotor arms 10, an annular portion of the substantially circular clear cross-sectional area 11 of the mixing pot 1 is swept over, in FIG. 5 easy to recognize.

In the FIG. 3 shows that the rotor arms 10 are inclined relative to the rotational direction 12 of the rotor 8 to the rear, so that in the mixing pot 1 befindliches mix is conveyed by the rotor 10 in the axial direction from the mixing pot 1 into the interior of the mixing vessel. This axial promotion is supported by further rotor arms 13, which, as in the FIG. 2 represented, are also present on the rotor 8.

The rotor arms 13 have with respect to the rotational direction 12 a slope, as shown in the FIG. 4 is shown.

Both the rotor arms 10 and the rotor arms 13 mesh with stator teeth 14 which project radially inward on the wall of the mixing pot 1 in the radial direction. Between these stator teeth 14 and the rotor arms 10 and 13, respectively, narrow grinding gaps 15 are formed, which lead to a high shear of mixing material in the mixing pot.

As a result of the rotation of the rotor 8 in the direction of rotation 12, mixed material is conveyed out of the mixing pot into the interior of the mixing container via the rotor arms 10 and 13 in an annular, radially outer region. At the same time, mixing material is thereby sucked out of the mixing container along the axis 9, which then strikes the end of the shaft 7 and is then guided radially outwards by the rotor 8 via centrifugal forces, so that it then returns via the rotor arms 10 and 13 in the axial direction can be promoted into the interior of the mixing container.

In the embodiment described so far, the mix is crushed by the rotor arms 10 and 13 in connection with the stator teeth 14 through the grinding gaps 15.

In the area of these stator teeth 14, a liquid supply 25 is also provided. Through this liquid can be introduced in the region of highest shear in the mix and distributed in this.

In addition to the described design with rotor and stator on the mixing pot wall, which are used for an intensive mixture of mix, which is ejected from the mixing pot, it is also possible, the mixture at its axial entry into the mixing pot via a radially on the inner region to guide limited knife ring 16, as in the FIGS. 6 and 8 is shown.

Also in this embodiment, the rotor 8 at its radial ends rotor arms 17 which sweep over a radially outer annular region which extends over the entire depth 6 of the mixing pot 1. Like in the FIG. 7 It can be seen, these rotor arms 17 have an inclination relative to the rotational direction 12, so that they cause the axial conveyance of the mixed material from the mixing pot 1, which simultaneously causes the intake of mixed material in the radially inner region, which then passed over the knife ring 16 and thereby mixed and / or crushed.

In the FIGS. 9 to 11 rotors 8 are shown having at their radially outer ends rotor arms 18 which are occupied with extending radially cutting blades 19. It is in the FIG. 9 to recognize that there exist all existing cutting blades of the rotor arms 18 radially inwardly, while in the FIG. 10 is shown that the cutting blades 19 are mounted on the different rotor arms 18 alternatively radially inward or radially outward. In the FIG. 11 one recognizes further a rotor 8, in which the cutting blades 19 are only partially provided on the rotor arms 18 present there. The other rotor arms are mainly used for axial ejection of mix.

The rotor arms 18 themselves are again made in a length so that they extend in their rotation substantially over the entire depth of the mixing pot, in which they are used without protruding from the mixing pot. One recognizes in the FIGS. 9 to 11 also in each case that the rotor arms 18 have a tendency over which they then have over the entire depth of a mixing pot an axial conveying action on the moving material from them. This is crushed by the passing through cutting blades, mixed etc.

But it is also within the scope of the invention, if individual rotor arms have a tendency for the described axial promotion and other rotor arms are occupied with blades. Here, a separation of promotion and mixers is achieved.

In the same way, in an embodiment according to the Figures 1 - 5 individual rotor arms mesh with stator teeth, while other rotor arms only effect the axial conveyance of mixed material.

It should also be mentioned at this point that a mixing pot not only can have the substantially cylindrical shape shown in the accompanying drawings, but that also a conical shape can be used. This is depending on procedural requirement to form the mixing container opening or closing.

In the FIG. 12 one recognizes a mixing container 20 in the side view. The present case is a substantially horizontally lying mixing trough. At this mixing container corresponding mixing pots 1 are provided over the circumference at any axial points, in which case only one drive motor 21 is shown by several of the rotors present in these mixing pots. These drive motors are flanged in a known manner to the mixing pots 1, where they are connected to the shafts 7.

In the FIG. 13 recognizes the mixing container 20 in axial view, wherein in this mixing container, a mixing tool, not shown, rotates in the direction of the arrow 22.

At a thought in the FIG. 13 On the mixing container placed dial, which is arranged at 12:00 clock top, the mixing pots are preferred arranged in the range between 3:00 and 11:00 clock, since in this area the mix contained in the mixing container 20 is moved by the mixing tool and thus there is particularly good in the mixing pots to withdraw and back into the interior of the mixing pot.

In the FIG. 14 It is also shown that the wall 23 of the mixing pot 1 is provided with a closable discharge opening 24 for the mixing container 20.

When this discharge opening 24 is opened, the rotor located within the mixing pot 1 is preferably moved counter to its usual direction of rotation 12 via the shaft 7. Thus, the mix is conveyed out of the interior of the mixing container 20 and simultaneously transported via the centrifugal force of the rotor 8 to the discharge opening 24. One thus has a particularly good opportunity to empty the mixing container quickly.

Claims (9)

1. Mixing device with a mixing container (20) into which a mixing tool is incorporated that sweeps along the wall (3) of the mixing container (20) where on said wall (3) a mixing pot (1) featuring a depth (6) is mounted and which is open towards the inside of the mixing container (20) in which rotates, around an axis (9) oriented towards the interior of the mixing container (20), a rotor (8) with rotor arms (10, 17, 18) which have an effect of turning out the mixture, with the rotor arms (10, 17, 18) not extending outside of the mixing pot (1),
   characterized in that the rotary arms (10, 17, 18) are inclined backwards relative to the rotational direction (12) of the rotor (8) and sweep over a radially confined area essentially covering the entire depth (6) of the mixing pot (1).
2. Mixing device according to Claim 1,
   characterized in that the area swept by the rotary arms (10, 17, 18) is located radially outside in the mixing pot (1).
3. Mixing device according to Claim 1,
   characterized in that within an area parallel to the axis and radially inside of the mixing pot (1) a blade (16) is located which minces the mixture.
4. Mixing device according to Claim 1,
   characterized in that radially extending cutting blades are positioned on the rotor arms (18).
5. Mixing device according to Claim 1,
   characterized in that the rotor arms (10) are combing, while forming grinding apertures with stator teeth (14) protruding radially from the mixing pot wall.
6. Mixing device according to one or several of the preceding claims,
   characterized in that, in addition to rotor arms which are inclined backwards relative to the rotational direction of the rotor and which have an ejecting effect, separate rotor arms are provided which comb with stator teeth protruding from the mixing pot wall while forming grinding apertures.
7. Mixing device according to Claim 1,
   characterized in that the mixing pot (1) features at least one feed opening (25) for adding a liquid.
8. Mixing device according to Claim 7,
   characterized in that the feed opening(s) (25) is (are) located on the wall of the mixing pot.
9. Mixing device according to Claim 1,
   characterized in that a lockable drain opening (24) is located on a wall of the mixing pot (1).

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