DE8333124U1 - Device for mixing and homogenizing preferably pasty mixtures - Google Patents

Description

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Patent Attorneys · European Patent Attorneys Bremen · Munich·

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M^*B**H«*^73.D.»»ii«~.l ' H««MeissnerDipl.-Ing. (until 1980)

Break Bolt · Dipping.

. _„,_ &igr; j__ . Dr. Eugen Popp · Dipl.-Ing., Dipl.-Wirtech.-Ing.·

uWK ^a ßf· Wolf E. Sejda · Dlph-Phy».·

Alwin ßerents GmbH ft Co. KG Dr.^al&pgr;v.Bu1ow.D^pUng^ _< Dlpl..w^ttsdl.·In&bgr;.· Henlelnstraße 19 office/ofpice bremen

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D-ttOÖ Bremen 1

Telephone: (0421) 342019 Teletext: PATMBIS BREMEN Telex: 24* UTmeibod

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BER-17-DE

17 November 1983/9119

Device for mixing and homogenizing preferably pasty mixtures

Description

1 The invention relates to a device for mixing and homogenizing preferably pasty mixtures according to the preamble of claim 1.

Devices of the type mentioned here are usually used to produce creams or ointments for the pharmaceutical or cosmetic industry, but also doughy masses for the food and chemical industries. The main aim here is to mix liquid substances of different viscosities or solid substances with one another as evenly as possible.

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Devices of the type mentioned at the beginning are particularly suitable for these purposes because, in conjunction with the homogenizer, they enable particularly intensive mixing of these substances which are difficult to mix. An absolutely homogeneous mixture is essential, particularly for creams or emulsions for pharmaceutical purposes. It must be possible to move all of the mixed material contained in the mixing container, i.e. reliably prevent the formation of ^" chemical nests" which tend to form on the walls of the mixing container and on the mixing elements. Finally, the aim is to empty the mixing container as residue-free as possible and to easily clean the entire mixing device without the need for laborious manual intervention.

Generic devices known for this purpose usually have a cylindrical mixing container with an upright longitudinal central axis. The homogenizer is usually mounted centrally under the bottom of the mixing container.

2ö. The drive of the mixing elements is from above , ie the drive is assigned to the lid of the mixing container. In such a known device, the lid is relatively heavy. It cannot usually be opened using a side hinge, but must be raised using complex devices so that the stirring tools do not hit the walls of the mixing container. Cleaning such a device must be carried out in two stages, namely by cleaning the raised agitator and the mixing container separately. To prevent this, it is already known to arrange the drive for the mixing elements in the middle of the bottom of the mixing container, but this requires an off-center outlet opening with a homogenizer. Complete emptying of the mixed material from the mixing container is then no longer possible, since the drive for the mixing element is already located at the lowest point of the mixing container bottom.

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Furthermore, known devices have a significant disadvantage in terms of mixing technology. This occurs particularly with highly viscous substances when the entire mixture contained in the mixing container rotates with the agitator elements. A mixing effect then practically no longer occurs because the mixture is no longer moved within itself, as intended.

but rotates as a whole in the mixing device. IO

In order to remedy this disadvantage, improved devices are known in which so-called flow breakers are fixed inside the mixing container. These prevent the entire mixing material from rotating by slowing it down and breaking it up according to the principle of a chicane. However, these flow breakers have several disadvantages. They require increased drive power for the agitator, create additional equipment expenditure and also have to be cleaned.

Instead of this flow breaker, agitator arms arranged off-center in the mixing tank are also known. However, these require a second, separate drive, since the wall scrapers that are to be moved along the inside of the agitator tank wall must in any case be driven centrally.

The invention is therefore based on the object of creating a device for mixing - while avoiding the disadvantages mentioned at the beginning - which creates a homogeneous mixture with high mixing performance, is easy to clean and has a mixing container that can be completely emptied and a lid of low weight.

To achieve this object, the device according to the invention has the characterizing features of claim 1.

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The inclined mixing container in conjunction with the horizontal level of the mixed material in it results in an uneven distribution of the mixed material mass in the mixing container in relation to the longitudinal center axis of the same. This effectively prevents the entire mixed material from rotating with the agitator elements. In this way, the upper parts of the agitator are constantly immersed in and out of the mixed material mass. Powdered mixed material components on the mixed material level are thus incorporated into the mixed material mass within a very short time. This also means that additives subsequently added to the mixing process are quickly mixed with the rest of the mixed material.

Due to the inclined arrangement of the mixing container, the agitator can be arranged centrally in the mixing container, with the axis of rotation lying in the longitudinal center axis of the mixing container. Despite such an arrangement of the mixer in the mixing container, due to its relative position

does not lead to rotation of the mixed material within the pre-20

direction.

According to a further proposal of the invention, the agitator can be driven from the bottom of the mixing container, with a drive arranged centrally under the bottom of the mixing container. Such an arrangement of the drive is particularly simple, whereby the entire agitator can be designed symmetrically in relation to the mixing container. According to the invention, the entire agitator with the agitator elements and the homogenizer are thus arranged on the bottom of the mixing container. The lid of the latter is thus completely free of weighty elements, for example drives. In this way, it can easily be opened sideways using one or more hinges. This can be done if necessary with mechanical aids, in particular a

hydraulic cylinder.

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The outlet opening for the mixed material is located next to the drive for the mixing tool, i.e. off-center, but at the lowest point of the mixing container in the bottom of the same. This is possible in this case because the incline of the mixing container means that its lowest point in the bottom is inevitably outside the center of the bottom. This arrangement ensures that the mixer is completely emptied, even though the drive for the stirring tool takes up the center of the bottom of the mixing container. 10

In a particularly advantageous embodiment of the invention, the homogenizer is arranged directly under the outlet opening of the mixing container. For this purpose, the homogenizer is directly connected to the bottom of the mixing container. This arrangement ensures that the mixed material is sucked directly into the homogenizer even when the full vacuum is maintained in the mixing container.

Alternatively, the homogenizer can also be arranged at a slight distance from the outlet opening under the bottom of the mixing container. There is then a short pipe socket between the outlet opening in the bottom and the homogenizer. The latter can also be designed as a pipe bend. The homogenizer can then be arranged inclined or upright under the mixing container of the mixer. This arrangement of the homogenizer can be advantageous for special purposes or mixing tasks of the device according to the invention, especially when a relatively thin mixture is to be processed.

In a particularly advantageous embodiment of the invention, the mixing container consists of a cylindrical middle part, the lower end of which has a curved bottom, in particular a clapper bottom. The latter has a curvature in the form of a spherical section for the most part.

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with a large radius, with the ends forming an arc-shaped transition to the lower front side of the cylinder shell. Such a bobbin base has an approximately elliptical cross-section. The lid of the niche container is preferably designed in the same way.

The advantage of such a mixing container base or lid is that the openings arranged in it - as long as they are not in the area of the transition radius to the middle part of the mixing container - necessarily have an almost cylindrical surface. The usually circular homogenizer or corresponding nozzles of pipes or the like can be easily attached to this.

Further features of the invention relate to the design of the agitator with the wall scrapers and the agitating tools.

Two embodiments of the invention are explained in more detail below with reference to the figures of the drawing.

Show it:

Fig. 1 is a vertical section through a device according to the first embodiment, and

Fig. 2 is a vertical section through a device according to the second embodiment.

The two embodiments of the device according to the invention shown here have a mixing container 10 with a cylindrical middle part 11. The middle part 11 is followed by a base, here designed as a curved clapper base 12. A top cover 13 of the mixing container 10 has a similar curvature. The latter closes the upper end face of the middle part 11.

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6-way mixing container 10 of the device is firmly connected to a frame 14 in such a way that the mixing container 10 is inclined relative to a vertical.

An agitator in the mixing container 10 is designed here as an anchor agitator IS with a likewise inclined rotation axis 16, which lies approximately in a longitudinal center axis 17 of the mixing container 10. The anchor agitator | IQ 15 is driven from the underside of the mixing container 10. For this purpose, the drive element 18 for the anchor agitator IS is arranged centrally under the clapper base 12.

Next to the drive element 18 there is an outlet opening Id in the lowest point of the clapper base 12. The outlet opening 19 is assigned a homogenizer 20, which in the embodiments presented here has the structure of a multi-ring rotor-stator system. The two embodiments of the device differ in the arrangement and position of the homogenizer 20 under the mixing container 10.

In Fig. 1, the homogenizer 20 is arranged directly under the clapper base 12 of the mixing container 10 and is connected to it. In this embodiment, the homogenizer 20 is therefore located directly in or under the side outlet opening 19 of the mixing container 10. On the underside of the homogenizer 20, an outlet nozzle 21 is arranged on the side, which leads - in a manner known per se - to a three-way valve 22. The latter is assigned both an outlet line 23 for emptying the mixing container and a circulation line 24, which leads to an inlet nozzle 25 arranged here on the side in the cover 13. The mixing material can be circulated in the device during the mixing process through the circulation line 24.

A drive motor 26 for the homogenizer 20 is centrally

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arranged underneath it. An electric motor can be used as the drive motor 26, for example. In this arrangement, a rotation axis 27 of the homogenizer 20 is vertical, i.e. the homogenizer 20 is arranged approximately horizontally underneath the mixing container 10.

In the second embodiment according to Fig. 2, however, the homogenizer 20 lies approximately upright with an approximately horizontal axis of rotation 28. The mounting of the homogenizer 20 with a drive motor not shown in Fig. 2 is carried out here by a separate stand 29.
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Due to the position and arrangement discussed above, in this embodiment the homogenizer 20 is not directly connected to the mixing container 10 or the clapper base 12 thereof. A pipe bend 30 is arranged between the outlet opening 19 of the mixing container 10 on the one hand and the homogenizer 20 on the other. The pipe bend 30 that continues the outlet opening 19 has a bend angle of approximately 90° here. To ensure that the mixed material flows to the homogenizer 20 with as little friction as possible, the pipe bend 30 is designed to be slightly funnel-shaped in such a way that it tapers towards the homogenizer 20*

Behind the homogenizer 20, a three-way valve (not shown in Fig. 2) with an outlet line (also not shown) and a circulation line 24 can also be arranged here.

Otherwise, both embodiments have an approximately identical structure. The same reference numbers designate the same parts of the device*

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The clapper base 12 has a curvature in the form of a spherical segment. The edges of the clapper base 12 are strongly rounded as a transition to the middle part 11 of the mixing container 10. In this way, the clapper base 12 has an approximately elliptical cross-section, which is clearly visible in the figures. The inclination of the mixing container 10 is selected here so that the deepest point of the clapper base 12 is on the edge of the spherical segment-like curvature of the same, i.e. shortly before the strongly rounded transition to the middle part 11 of the mixing container. As a result, the outlet opening 19 in the clapper base 12 has an approximately circular cross-section.

The lid 13 of the mixing container 10 has a similar shape. This is connected to the mixing container 10 or its frame 14 by a lateral hinge 31 with an approximately horizontal pivot axis 32. A pivotable hinge part 33 has a cantilever arm 34 that protrudes beyond the pivot axis 32. The latter is connected in an articulated manner to a piston 35 of a pressure medium element 36, for example a hydraulic cylinder, the cylinder 37 of which is in turn articulated to the frame 14 of the device. The lifting movement of the pressure medium element 36 means that the lid 13 of this embodiment can be opened and closed again in a simple manner.

A dividing line 38 between the middle part 11 and the eyelet 13 of the mixing container 10 runs here approximately at right angles to the longitudinal center axis 17 of the mixing container 10. The dividing line 38 is selected so that it ends at a slight distance from the radius outlet of the circumferential arc adjoining the edge of the spherical section of the lid 13. This creates a short cylindrical section on the lid 13, on which an external, circumferential sealing ring 39 is arranged. A corresponding

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A sealing ring 40 is arranged on the upper free part of the middle part 11 of the mixing container 10. The surfaces facing each other on the sealing ring 39 and on the sealing ring 40 are inclined, whereby a circumferential truncated cone-shaped sealing surface 41 is created on the dividing line 38. To support the sealing effect, a circumferential seal 42 is arranged in the (upper) sealing ring 39 on the cover 13.

Due to the placement of the drive shaft 18 for the anchor agitator 15 as well as the outlet opening 19 or the homogenizer 20 on the clapper bottom 12 of the mixing container 10, in this embodiment, the lid 13 only has.

an inlet nozzle 25 for the circulation line 24 coming from the homogenizer 20. In addition, one or more sight glasses and mixing material feed openings can be arranged on or in the cover 13. However, these do not significantly increase the weight of the cover 13.

The anchor agitator 15 consists in the present version

iring examples from a U-shaped agitator arm 43. Both wall scrapers 44 and agitator tools 45 are arranged on this. The shapeless profile of the agitator arm 43 corresponds approximately to the cross section of the mixing container 10. The two opposite legs 46 of the agitator arm 43 run parallel to the wall of the middle part ti of the mixing container at a slight distance. A web connecting the legs 46 of the agitator arm 43

3Q 47 is slightly angled at its two ends directed towards the legs 46, so that it also runs approximately parallel to the clapper base 12 of the niche container 10. In this embodiment, six wall scrapers 44 are arranged at a distance from one another between the agitator arm 43 and the skirt part 11 as well as the clapper base 12 of the mixing container 10. These are arranged asymmetrically on the agitator in relation to the inclined axis of rotation 16 of the anchor agitator 15.

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work arm 43; in each case on a "gap". This means that the part of the mixing container 10 not covered by the wall scrapers 44 of one half of the anchor agitator 15 is cleaned by the wall scrapers 44 on the opposite side. In this way, the formation of mixed material nests on the inner walls of the mixing container 10 is almost completely prevented.

With respect to the outlet opening 19 in the clapper base 12 of the mixing container 10, the two wall scrapers 44 arranged on the web 47 of the agitator arm 43 are designed in such a way that they each cover only half of the outlet opening 19. A jamming of the wall scrapers 44, which are cardanically mounted on the agitator arm 43, at the edges of the outlet opening 19 is thus prevented.

The fully cardanic mounting of the wall scrapers 44 on the agitator arm 43 is carried out by two bearing pins 49 per wall scraper 44 that are firmly connected to it. The bearing pins 49 in turn engage with ball heads and play in the plates 48 of the wall scrapers 44. They can therefore be freely pivoted in all directions to a limited extent. A leaf spring not shown in the figures serves to press the wall scrapers 44 onto the inner walls of the mixing container 10. Such a mounting of the wall scrapers 44 is shown, for example, in DE-OS 28 15 946. It is particularly suitable for curved mixing containers 10. If the design of the mixing containers 10 allows it, the wall scrapers 44 can of course also be mounted on the agitator arm 43 in a different way.

In this embodiment, three stirring tools 45 are attached to the side of the stirring unit 43" facing away from the wall scrapers 44, namely to the legs 46. The stirring tools 45 consist of approximately square plates 48 with two diagonally opposite holes 50.

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The plates 48 of the stirring tools 45 are connected to the

opposite legs 46 of the agitator arm 43 by approximately horizontally directed arms 51. The distribution of the three plates 48 of the agitator tools 45 on the agitator arm 43 is selected in this embodiment such that two agitator tools 45 are attached to one leg 46 at a distance from one another, while only one agitator tool 45 is located on the opposite leg 46. In terms of height, in relation to the axis of rotation 16, the individual agitator tool is arranged approximately between the two opposite agitator tools 45.

The plates 48 of the stirring tools 45 can - as here - be rotated around the longitudinal axis of their arms 51, and indeed also to different degrees or in different directions, so that the three plates 48 do not lie in a common plane. In contrast, the plates 48 can alternatively also lie in a common, upright plane (drawing plane in the

Representation in Fig. 1 and 2). 20

With such a design of the anchor agitator 15 in conjunction with the inclined mixing container 10, a particularly intensive mixing of the mixture is possible, even through a vertical mixing movement. Due to the distribution of the stirring tools 45 along the axis of rotation 16 of the anchor agitator 15, even the smallest batches of mixture can be mixed effectively with the device, since the mixture is above the discharge opening 19

collects in the inclined mixing container 10. In this respect 30

Due to the design of the device according to the invention, it is not necessary for the mixing material level 52 to have the height shown in Fig. 1. Rather, a sufficient mixing result can also be achieved if the mixing material level 52 only has the height shown in Fig. 2.

set height is reached, which however does not have to be the minimum height.

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The drive element 18 arranged centrally under the clapper base 12 of the mixing container consists here of a combination of several units that allow a continuous change in the rotation frequency of the anchor agitator 15. For this purpose, in this embodiment, a hub 53 arranged centrally on the web of the agitator arm 43 is mounted with an axle stub 54 in a bearing 55 connected to the clapper base 12. At the same time, the bearing 55 serves to seal the axle stub 54 from the clapper base 12. A worm drive 56 is arranged below the bearing 55. In the embodiment of Fig. 1, this is driven by a continuously variable, adjustable control drive 57, for example an SEW drive, to which an electric motor not visible in this figure is assigned.

Alternatively, as shown in Fig. 2, the worm drive 56 can be driven directly by an electric motor 58. In this case, the drive frequency of the anchor agitator 15 is adjusted either in steps by a pole-changing motor or continuously by a thyristor-controlled AC motor or by a DC motor.

The present embodiments show a mixing container 10 with a double wall in the lower area for heating or cooling the mixture contained therein. In addition, the mixing container 10 can be surrounded by an insulating jacket 59 shown in dash-dotted lines in the figures.

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The frame 14, on which the mixing container 10 is held at an angle, consists in this embodiment of three feet 60, which are firmly connected to the mixing container 10 in the area of the g ₅ double jacket. The feet 60 can have height-adjustable base plates 61 at their lower ends directed towards the ground. The latter enable, to a certain extent,

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Frame a change in the inclination of the device, in particular for the purpose of adjustment

I Meissner & Bolte

I Patent Attorneys

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Animal of:

Alwin ßerents GmbH & Co. KG Henleinstr. 19

2805 Stuhr-1

Bremen, 17 November 1983/9119 List of reference symbols

10 Niche container 36 Pressure medium organ 11 Middle part 37 cylinder 12 Bobbin bottom 38 parting line 13 Lid 39 Sealing ring 14 frame 40 Sealing ring IS Anchor agitator 41 Sealing surface 16 Rotation axis 42 poetry 17 Longitudinal center axis 43 Agitator arm 18 Drive unit 44 Wall scraper 19 Outlet opening 45 Stirring tool 20 Homogenizer 46 leg 21 Outlet nozzle 47 web 22 Three-way valve 48 plate 23 Outlet line 49 Bearing journal 24 Circulation line 50 drilling 25 Inlet nozzle 51 poor 26 Drive motor 52 Mixture level 27 Rotation axis 53 hub 28 Rotation axis 54 Stub axle 29 Stand 55 camp 30 Pipe bend 56 Worm drive 31 hinge 57 Rege!trieb 32 Swivel axis 58 Electric motor 33 Hinge part/pivoting 59 Insulating jacket 34 cantilever 60 Foot 35 Pistons 61 Stand plate

Claims (1)

Expectations 10 1. Device for mixing and homogenizing preferably pasty mixtures, with a mixing container fixedly mounted on a frame, which has an agitator arranged inside and an outlet opening for the mixture, to which a homogenizer is assigned, characterized in that the mixing container (10) is arranged in the frame (14) inclined with respect to its longitudinal center axis (17) with an outlet opening (19) located at the lowest point of the mixing container (10). -2- 2. Device according to claim 1, characterized in that the tube (anchor agitator 15) with the axis of rotation lying in the longitudinal center axis (17) of the mixing container (10) (16) is arranged therein.
5 3. Device according to claim 1 and 2, characterized in that the agitator (anchor agitator 15) can be driven from a bottom side of the mixing container (10). 4. Device according to one or more of the claims 1 to 3, characterized in that a drive element (18) of the agitator (anchor agitator 15) is arranged centrally under a bottom (clapper bottom 12) of the mixing container (10). 5. Device according to claim 1 and one or more of the further claims, characterized in that the outlet opening (19) is arranged next to the drive element (18) of the agitator (anchor agitator 15) at the lowest point in the bottom (clapper bottom 12) of the mixing container (10) is. 6. Device according to claim 1 and one or more of the further claims, characterized in that the homogenizer (20) is located directly below the outlet opening (19) is arranged on the bottom (clapper bottom 12) of the mixing container (10). 7. Device according to claim 1 and one or more of the further claims, characterized in that the homogenizer (20) is arranged approximately upright under the bottom (clapper bottom 12) of the mixing container (10) with a pipe bend (30) for connecting the outlet opening (19) in the bottom (clapper bottom 12) of the mixing container (10) with the homogenizer (20).
36 I««· It(It. I 1 · I I t « « t III ·« Iff III V * It -3- 8. Device according to claim 7 and one or more of the further claims, characterized in that the pipe bend (30) gradually tapers towards the homogenizer (20). 9. Device according to claim 1 and one or more of the further claims, characterized in that the agitator is designed as an anchor agitator (IS). io. Device according to claim 9 and one or more of the further claims, characterized in that the anchor agitator (IS) has a U-shaped agitator arm (43) which runs parallel to the walls of the mixing container (10) at a distance. 16 11. Device according to claim 9 and one or more of the further claims, characterized in that on the side of the agitator arm (43) directed towards the walls of the mixing container (10) wall scrapers (44) are arranged, in particular are mounted fully cardanically. 12. Device according to claim 11 and one or more of the further claims, characterized in that the wall scrapers (44) are arranged at a distance from one another on the agitator arm (43), wherein, with respect to two halves of the agitator arm formed by the axis of rotation (16) of the agitator arm, the free spaces of one half of the agitator arm (43) formed by a pair of wall scrapers (44) are assigned to wall scrapers (44) on the opposite half of the agitator arm (43) for almost completely scraping all walls of the mixing container (10). 13. Device according to claim 9 and one or more of the further claims, characterized in that stirring tools (45) are arranged on the mutually directed (inner) sides of (upright) legs (46>) of the U-shaped stirring arm (43). -4- 14. Device according to claim 13 and one or more of the further claims, characterized in that the stirring tools (45) are arranged asymmetrically and in different numbers on the two legs (46) of the stirring arm (43). 15« Device according to claim 13 and one or more of the further claims, characterized in that the stirring tools (45) are designed as plates (48) which are held on horizontal arms (51) at a distance from the stirring arm (43) and are inclined with respect to an upright central plane of the mixing container (10) for moving the mixed material in several, approximately horizontal and vertical directions. 16. Device according to claim 15 and one or more of the further claims, characterized in that the plates (48) of the stirring tools (45) have at least have one, in particular two holes (50). 20 17. Device according to claim 1 and one or more of the further claims, characterized in that the mixing container (10) has a cylindrical central part (11) with a curved clapper base (12) of approximately elliptical cross-section. 18. Device according to claim 16 and one or more of the further claims, characterized in that the clapper base (12) is curved in such a way that ^ä0 forms an approximately circular outlet opening (19). 19. Device according to claim 1 and one or more of the further claims, characterized in that a lid (13) of the mixing container (10) can be opened by means of at least one lateral hinge (31), preferably by a separate drive, for example a pressure medium element (36). Meissner & Bolte Patent Attorneys