EP3108957A1 - Mixing machine and inliner for same - Google Patents

Abstract

A mixing machine (1) comprises a mixing head (3) equipped with one or more elements for connecting the same to a container containing a mix for forming a mixing container containing the mixing mix, which mixing head (3) pivotally mounted relative to a frame (2) such in that the mixing container formed from the mixing head (3) and the container is pivotable for carrying out the mixing process. In the mixing head (3) at least one rotationally driven mixing tool is arranged, whose drive shaft (23) passes through the wall of the mixing head (3). The mixing head (3) is double-walled, wherein the inner wall (8) of the double-walled construction is perforated, through which perforations as Fluidwegsamkeit of the inner wall (8) enclosed space with that between the inner wall (8) and the outer wall (9) provided Wall space (10) is connected. The wall space (10) is connected to a for adjusting the pressure in the wall space (10) provided Druckeinstelleinrichtung. A flexible inliner (15) is arranged in the mixing head (3) for lining its inner surface provided by the inner wall (8), which inliner (15) acts on the inner wall (8) of the vacuum provided by the wall gap (10) Mixing head can be fixed Furthermore, an inliner for a mixing head of such a mixing machine is described.

Description

The invention relates to a mixing machine, comprising a mixing head, equipped with one or more elements for connecting it to a container containing a mix for forming a mixture containing closed mixing container, which mixing head is pivotally mounted relative to a frame such that the mixing head and container formed mixing container for performing the mixing process is pivotable, in which mixing head at least one rotationally driven mixing tool is arranged, whose drive shaft passes through the wall of the mixing head. Furthermore, the invention relates to an inliner, preferably for such a mixing head.

Such mixing machines are industrial mixers which are used for mixing, in particular, bulk material, typically powdered bulk material, such as is required for producing plastic granulate mixtures or else in the paint industry. These mixing machines have a comparison with a frame pivotally mounted mixing head, which also serves to seal a container containing the mix, which is connected to the mixing head for the purpose of mixing therein. After the container has been connected to the mixing head, a closed mixing container is formed from the mixing head and the container containing the mix. For the purpose of connecting the container to the mixing head, the mixing head has one or more connecting elements, for example a peripheral flange. Due to the fact that in these mixing machines a container containing the mix is connected to the mixing head, these mixers are also addressed as a container mixer. The container is also addressed as a mixed container. The mixing head itself is pivotally arranged relative to the machine frame of the mixing machine, so that the mixing with respect to the mixing head in an overhead position, in which the mixing head at the bottom and the mixing container connected thereto are located at the top. In this position, the lower-side discharge opening of the mixing container is facing upwards.

This overhead position is required for the mix to come in contact with the at least one mixing tool carried by the mixhead. The rotationally driven mixing tool is used to generate a Mischgutstromes within the closed mixing chamber. The duration of the mixing process determines the degree of mixing. Such an industrial mixer is for example off EP 0 225 495 A2 known.

With such mixing machines, the mix is mixed batchwise in the mixing container formed from each mixing container and mixing head. If the material composition of the mixed material is different between a first batch and a subsequent batch, the mixing head must be cleaned. This comprises cleaning the inner wall of the mixing head and the mixing tool or tools arranged therein. For this purpose, the mixing tools can and are removed from the mixing head.

In mixing machines of this type is sometimes observed that in the mixing head, especially in the area around the mixing tool or mixtures accumulate, which can adhere to the mix also at the bottom of the mixing machine. These material accumulations are already formed at the beginning of the mixing process, with the result that this material is decoupled from the further mixing process. This may occur in mixing heads having a slow rotating, typically soil clearing first tool and one or more faster rotating mixing tools such as these DE 20 2014 101 787 U1 or off DE 20 2009 001 937 U1 are known. With these mixing heads mixing of mix without significant heat input is possible. Since in mixing machines with such mixing heads the mixing is done in an overhead arrangement with underlying mixing tools falls when swinging back of the mixing head in the starting position after completion of the mixing process for decoupling the mixing container this not sufficiently mixed material on the underlying mixed mixture according to the intended. Even if the amount of this receding, not sufficiently mixed mixed material in relation to the amount of the intended mixed Mix is ultimately not appreciable, this sometimes falls on his compared to the intended mixed mixed different color. Moreover, it is undesirable if even small proportions of mixed material are not mixed properly. A disadvantage may also be, if such, not sufficiently mixed material adheres in the mixing head and remains in this as unmixed or not sufficiently mixed material accumulation.

Based on this discussed prior art, the invention is therefore the object of developing a mixing machine of the type mentioned in such a way that mixed with this can be mixed as intended while avoiding the above-outlined problematic mixture.

This object is achieved according to the invention by an aforementioned, generic mixing machine, wherein the mixing head is double-walled, wherein the inner wall of the double-walled formation is perforated, through which perforations as Fluidwegsamkeit the enclosed wall of the inner wall space provided between the inner wall and the outer wall wall space and the wall space is connected to a pressure adjusting means provided for adjusting the pressure in the wall gap, and wherein in the mixing head is arranged a flexible inliner for lining its inner surface provided by the inner wall, which inliner is pressurized by a negative pressure applied in the wall space can be fixed on the inner wall of the mixing head.

In this mixing machine, the mixing head is double-walled. It is provided that the inner wall is perforated to connect the interior of the mixing head by means of perforations forming the perforations as Fluidwegsamkeit with the located between the inner wall and the outer wall wall space. In the mixing head, a flexible inliner is used, which covers the surface of the inner wall facing towards the space enclosed by the mixing head and thereby also closes the perforations. The wall space is connected to a pressure adjusting device, via which the wall gap with a different from the ambient pressure Pressure can be applied. The wall gap is thus acted upon by the pressure adjusting device with negative pressure or with overpressure. The pressure adjusting device therefore has means for providing a negative pressure in the wall gap or also an overpressure. To provide a negative pressure can serve a vacuum pump. To provide an overpressure, a pressure pump. Both can also be achieved by a piston-cylinder arrangement or by connecting the wall gap to a hydraulic expansion tank.

If the inliner is inserted in the mixing head, which is necessary for the use of the mixing head for mixing a mixed material, the wall gap is subjected to a negative pressure, for example 0.3 to 0.5 bar below the ambient pressure. By this measure, the inliner is sucked to the inside of the inner wall and is fixed by this measure. The mixing process is carried out with a mixing container connected to this mixing head, as known from the prior art. In order to avoid that after completion of the mixing process unmixed mix falls on the rest, intended mixed material, at least once the mixing head with the mixing container connected thereto is swung back from its over-head mixing position to its original position, in which starting position the mixing head located above the mixing container. Material adhering to the inliner can fall away from it during this backward pivoting process and in this way becomes involved in the further mixing process. If the mixture is not or not sufficiently mixed, when the mixing head has been swung back to its starting position, adhere to the liner or should be such fear, the wall gap is subjected to a certain pressure, so that it dissolves from the region of the bottom of the mixing head and deformed in this direction similar to a process of milling. As a result of the deformation of the inliner, the adhesive bond of mixed material particles adhering to the inliner is released so that they then fall back into the mix below. After the wall space has been repressurized to re-aspirate the inliner, the mixing container is swung back into the mixing position and the Mixing process continued. If mixing material is to be decoupled from the mixing process by the further mixing process, this is no longer a mixture that is unmixed, but mixed material already mixed, by which the mixed batch, if it falls back there, is not impaired. This process can be repeated one or more times during the mixing process. For this reason, the inliner is flexible.

In a preferred embodiment, the inliner is made of an elastic or a rubber-elastic polymer, wherein the inside is preferably equipped with a adhesion-minimizing coating and / or equipped with such a surface structuring.

The inliner has a sufficient dimensional stability that this does not coincide when applying an overpressure in the wall space, but is solved only from the inside of the inner wall of the mixing head. Such pressurization may be limited to certain areas of the wall space and thus to certain areas of the liner. In such a case you will divide the wall gap into individual segments. This dimensional stability of an inliner can be achieved, for example, with a PTFE-coated rubber film having a material thickness of 2 to 3 mm.

In a further development, it is provided that the inliner carries at its edge facing the mixing container a flange projecting outwards in the radial direction. This flange also serves as a seal in the interface between the mixing head and a mixing container. This flange is then fixed in the said interface by the counter-flange of the mixing container pressed against pressure. If pressure is applied to the wall gap in such an embodiment, only the bottom of the inner wall will typically become detached due to the dimensional stability of the inliner. This area is also the one where material buildup, if any, is to be expected.

In a further development it is provided that a connection extension is formed on this flange of the inliner, for fixing the inliner the mixing head without a mixing container is connected thereto, engages in a circumferential groove of the wall space final ring body. The engagement of this connection extension in the circumferential groove of the mixing head is frictional or positive. In the former case, the connection extension engages in the manner of a piping edge in the groove. In a positive connection, the form-fitting groove is executed undercut and the connection extension has a thickened end portion, which is preferably designed as a hollow chamber profile in order to be inserted into the groove can.

Fig. 1:

eine schematisierte perspektivische Ansicht einer Mischmaschine mit einem an den Mischkopf derselben angeschlossenen, ein Mischgut enthaltenden Mischbehälter in Mischstellung,

Fig. 2:

einen schematisierten Querschnitt durch den Mischkopf der Mischmaschine der Figur 1, dargestellt ohne Mischwerkzeuge, mit einem darin eingesetzten Inliner,

Fig. 3:

eine vergrößerte Detaildarstellung des in Figur 2 gekennzeichneten Ausschnittes des Mischkopfes,

Fig. 4:

eine perspektivische Inneneinsicht in den Mischkopf ohne eingesetzten Inliner,

Fig. 5:

eine perspektivische Darstellung des in den Mischkopf der Mischmaschine der Figur 1 eingesetzten Inliners und

Fig. 6:

einen vergrößerten und detaillierterer Ausschnitt aus dem Boden des Mischkopfes im Bereich seiner Durchbrechung zum Durchführen einer Antriebswelle für ein Mischwerkzeug.

The invention is described below with reference to an embodiment with reference to the accompanying figures. Show it:

Fig. 1:

1 is a schematic perspective view of a mixing machine with a mixing container containing a mixing material connected to the mixing head thereof in the mixing position,

Fig. 2:

a schematic cross section through the mixing head of the mixing machine of FIG. 1 , shown without mixing tools, with an inliner inserted therein,

3:

an enlarged detail of the in FIG. 2 marked section of the mixing head,

4:

an inside perspective view into the mixing head without inserted inliner,

Fig. 5:

a perspective view of the mixing head of the mixing machine of FIG. 1 used inliners and

Fig. 6:

an enlarged and more detailed section of the bottom of the mixing head in the region of its opening for performing a drive shaft for a mixing tool.

A mixing machine 1 for industrial purposes has a machine frame 2, on which a mixing head 3 is pivotally mounted. The pivot axis of the mixing head 3 is denoted by the reference symbol S in FIG. 1 indicated. About a drive 4, the mixing head 3 is pivotable about its pivot axis S at least 180 °. In the illustrated embodiment, the pivotability of the mixing head 3 serves the purpose that in its opposite to the representation in FIG. 1 rotated by 180 ° position a mixing container 5 as a mixture containing container moved up to the mixing head 3 and can be connected to this, then the mixing container 5 and mixing head 3 formed unit - the actual mixing container - in the FIG. 1 shown position of the mixing head 3 to pivot. In this position, the mixing head 3 of the mixing machine 1 is at the bottom so that the mix contained in the mixing container 5 falls on the arranged in the mixing head 3 tools. This position represents the mixing position of the mixing head 3 of the mixing machine 1.

The mixing head 3 of the illustrated embodiment has two tools, which are each driven by an electric motor 6, 7 in the illustrated embodiments.

In the embodiment shown in the figures, the mixing head 5 is designed with its mixing tools, as in EP 2 460 581 A1 described mixing head according to the embodiment of FIGS. 1 to 3 , In this respect, this explicit reference to EP 2 460 581 A1 the relevant descriptions of the mixing head described therein made the subject of these statements and the description of the mixing head 3 of the illustrated embodiment.

FIG. 2 shows the mixing head 3 of the mixing machine 1 in a stand-alone view and without the mixing tools arranged therein including the drive shafts driving the tools. The mixing head 3 has a double-walled construction and comprises an inner wall 8 and an outer wall 9 enclosing the inner wall 8 while leaving a distance. In the exemplary embodiment illustrated, the outer wall 9 surrounds the inner wall in the manner of a box. Between the inner wall 8 and the outer wall 9 is a wall gap 10. The wall gap 10 is sealed from the outside environment. For this purpose serves a in FIG. 2 shown annular body 11, through which the inner wall 8 is connected to the lower end of the outer wall 9. Of the Annular body 11 also forms a connecting flange as an abutment against which the connecting flange of the mixing container 5 is pressed to form a mixing container 3 formed from the mixing head 3 and the mixing container with its connecting flange. The wall gap 10 serves in the mixing head 3 as a collector for a fluid, typically ambient air. The wall gap 10 can be acted upon by a negative pressure or an overpressure. For this purpose, the wall gap 10 is connected via a connection 12 and an attached connecting line to a pressure adjusting device in a manner not shown. With this, the pressure prevailing in the wall gap 10 pressure is adjustable.

Compared with the wall gap 10 sealed openings 13, 14 are used to perform the drive shafts of the mixing tools, not shown in the figure. In the mixing head 3 of the mixing machine 1, a rotationally driven soil-clearing tool is arranged through the opening 13, while the opening 14 of the drive shaft serves a more rapidly rotating and responsible for the actual mixing mixing tool.

The space enclosed by the inner wall 10 forms, together with the cavity of a mixing container connected to the mixing head 3, the mixing cavity. The inside of the inner wall 8 is lined with a flexible inliner 15. The arrangement of the inliner 15 on the inner wall 8 is in the enlarged view of FIG. 3 recognizable.

The inner wall 8 is perforated and carries in the manner of a grid distributed over its entire surface openings 16, with which the wall gap 10 is connected to the enclosed by the inner wall 8 cavity (see also FIG. 4 ). The inliner 15 of the illustrated embodiment is made of a rubber material in the manner of a film and carries on its in the enclosed by the inner wall 8 side facing a adhesion-minimizing coating, which is designed in the illustrated embodiment as a PTFE coating. The inliner 15 typically has a hardness Shore A between 50 and 70 and thus has a material elasticity that corresponds approximately to that of a vehicle tire. This means that the inliner 15 a has certain material elasticity. The inliner 15 carries at its end associated with the ring body 11 a circumferential flange 17 which projects in the radial direction. On the flange 17, a connection extension 18 is formed in the manner of a Paspelrandes, which engages in a circumferential groove 19 of the annular body 11. In the illustrated embodiment, the groove 19 is formed by a shoulder in the ring body 11 and the outside of the inner wall 8. The pioneering from the contact side of the annular body 11 connecting extension 18 is held frictionally in the groove 19. This ensures that the inliner 15 in the in the FIGS. 2 and 3 shown position remains, even if no mixing container is connected to the mixing head 3. The inliner 15 has a corresponding dimensional stability that he his in the FIGS. 2 and 3 shown shape without additional measures and does not fall into the enclosed by the inner wall 8 cavity, even if in the wall gap 10 no negative pressure is applied.

For complete fixation of the inliner 15 on the inner wall 8 of the wall gap 10 is subjected to a certain negative pressure, for example 0.3-0.5 bar below ambient pressure. Due to the sealing of the wall gap 10 relative to the environment, the inliner 15 is sucked to the inside of the inner wall 8 by this measure. This ensures that the inliner 15 also remains in a fitting operation in its intended position on the inside of the inner wall 8 fitting. The inliner 15 or the side pointing into the cavity is sufficiently abrasion-resistant for the mix to be mixed with the mixing head 3.

FIG. 5 shows the inliner 15, whose geometry is adapted to the geometry of the inside of the inner wall 8. In those places where the drive shafts or other means, such as sensors engage in the enclosed by the inner wall 8 cavity, the inliner 15 has corresponding openings.

FIG. 6 shows an enlarged sectional view of the region of the opening 13 for passing the drive shaft for a mixing tool through the bottom of the mixing head 3 and the inliner 15 disposed therein. The relevant opening of the inliner is through ring body 20th bordered, which is formed on the remaining components of the inliner 15. For stiffening, the ring body 20 may have a steel insert. The ring body 20 is designed to engage in a recess 21 of the bottom of the mixing head 3. In the opening 13 of the mixing head 3, a sealing bush 22 is inserted. This serves to seal the drive shaft 23, sitting on the free end of a mixing tool. Several shaft seals are held inside the sealing sleeve 22. The sealing bush 22 itself has a radially outwardly projecting flange 24, which is fastened by a plurality of screws 25 at the bottom of the mixing head 3. The arranged on the interior of the mixing head 3 side of the sealing bush 22 flange 24 has on its radial outer side a shoulder 26 which engages over a complementary shoulder of the annular body 20 of the inliner 15. By this grip of the flange 24 with its projection formed by the shoulder 26 of the annular body 20 is connected to the mounted sealing bush at the bottom of the mixing head 3.

The through-holes 13, 14 sweeping drive shafts are compared to the openings 13, 14 sealed by a gap seal by these are flushed with gas, from the outside inwards. As a result, the internal pressure in the mixing container is slowly increased during the mixing process, so that the fixation of the inliner on the inside of the inner wall 8 is additionally supported by this measure.

In order to obtain at the end of the mixing process no or insufficiently mixed material deposits in the interior of the mixing head 3, the mixing head 3 is pivoted to its normal position after a first mixing phase, so that the mixing head 3 is again at the top. To support a drop of not or insufficiently mixed material deposits within the mixing head 3, so that they fall back into the mix, the wall gap 10 is subjected to a certain overpressure against the pressure in the mixing container, for example 0.3 - 0.5 bar. This causes the inliner 15 to lift off the inside of the inner wall 8, thus being deformed due to its flexibility. This walk-like deformation dissolves Mischgutablagerungen adhering thereto and fall back into the mix contained in the mixing container. Subsequently, the mixing process is continued. Incorporated into the mix, previously not sufficiently mixed material is mixed in the progress of the mixing process. If repeated material deposits should be observed, these are then no longer mixed mix.

An advantage of using an inliner, as set forth in the preceding embodiment, moreover, is that this can easily be equipped with adhesion-minimizing coatings, at least in a much simpler manner than a steel surface.

To clean the mixing head 3, the inliner 15 can basically remain in the mixing head 3. Against the background that for the cleaning of the mixing head 3 as a rule the mixing tools are removed from the mixing head 3, it makes sense in the cleaning of the mixing head to replace the inliner 15. If it is to be expected that a batch of mixed material having the same material composition is to be mixed again, such an inliner 15 removed from the mixing head 3 need not be cleaned. If a Mischgutarge is mixed again, which corresponds to that which has been mixed with the inliner 15, you can use this uncleaned in the mixing head 3. This not only reduces the time required for a cleaning of the mixing head 3, but also associated costs and reduces the use of cleaning fluid or reduces the amount of cleaning fluid to be disposed of.

Although in the described embodiment, the inliner 15 is made of a material resistant to abrasion with respect to the mixed material to be mixed, the claimed concept can also be used to introduce an abrasion in the mix. The inliner is then made of such a material or has an existing of such a material, pointing into the mixing cavity coating.

The invention has been described with reference to an embodiment. Without departing from the scope of the applicable claims, numerous other ways for the skilled person to implement the invention.

LIST OF REFERENCE NUMBERS

1

mixer

2

machine frame

3

mixing head

4

Rotary actuator

5

mixed container

6

electric motor

7

electric motor

8th

inner wall

9

outer wall

10

Wall space

11

ring body

12

connection

13

perforation

14

perforation

15

inline

16

perforation

17

flange

18

Connecting projection

19

groove

20

ring body

21

deepening

22

packing sleeve

23

drive shaft

24

flange

25

screw

26

paragraph

S

swivel axis

Claims (13)

A mixing machine, comprising a mixing head (3) equipped with one or more elements for connecting it to a container containing a mixture for forming a closed mixing container containing the mixture, which mixing head (3) is pivotally mounted relative to a frame (2) such that in which mixing head (3) at least one rotationally driven mixing tool is arranged, whose drive shaft (23) passes through the wall of the mixing head (3), characterized in that the Mixing head (3) is double-walled, wherein the inner wall (8) of the double-walled formation is perforated through which perforations as Fluidwegsamkeit of the inner wall (8) enclosed space with the between the inner wall (8) and the outer wall (9) provided wall space (10) is connected, and the wall space (10) to one m is set to adjust the pressure in the wall space (10) provided Druckeinstelleinrichtung, and that in the mixing head (3) a flexible inliner (15) for lining its by the inner wall (8) provided inner surface is arranged, which inliner (15) through one in the wall space (10) adjacent negative pressure on the inner wall (8) of the mixing head is fixable Mixing machine according to claim 1, characterized in that the inliner (15) carries at its end pointing away from the bottom of the mixing head (3) a circumferential flange (17) projecting outwards in the radial direction. Mixer according to claim 2, characterized in that the flange (17), a peripheral connecting projection (18) is formed of the liner (15) in a circumferential groove (19) of the inter-wall space (10) closing the annular body (11) engages, wherein the flange (17) of the inliner (15) also serves as a seal between the mixing head (3) and a mixing container connected thereto. Mixing machine according to one of claims 1 to 3, characterized in that the inliner (15) by an annular body (20) edged opening in the region of its bottom for performing a mixing tool carrying drive shaft (23) by means of a clamping ring on the ground of the mixing head (3) is held. Mixer according to claim 4, characterized in that the clamping ring for holding the annular body (20) of the liner (15) of the radially outwardly projecting flange (24) of the bottom of the mixing head (3) through cross-sealing socket (22). Mixing machine according to one of claims 1 to 5, characterized in that the wall gap (10) can be acted upon by the pressure adjusting device with overpressure. Mixing machine according to one of claims 1 to 6, characterized in that the inliner (15) is made of an elastic or a rubber-elastic polymer. Mixing machine according to claim 7, characterized in that the inner wall of the inliner (15) is equipped with a adhesion-minimizing coating and / or is equipped with such a surface structuring. Inliner for a mixing head of a mixing machine, which mixing head (3) is equipped with one or more elements for connecting it to a container containing a mixture for forming a mixing container containing closed mixing container, in particular for use in a mixing machine according to one of claims 1 to 6 , characterized in that the inliner (15) has a size and shape to completely cover the inner surface of the mixing head (3) and the inliner (15) at its from the bottom of the mixing head (3) facing away from a circumferential, in radial direction outwardly projecting flange (17) carries. Inliner according to claim 9, characterized in that on the flange (17) of the inliner (15) a connection extension (18) is formed, designed to be in a circumferential groove (19) of an inner wall (8) of the mixing head (3). to engage connected ring body (11). Inliner according to claim 9 or 10, characterized in that it has a by an annular body (20) enclosed bottom opening for the purpose of cutting through a drive shaft (23) for a mixing tool. Inliner according to one of claims 9 to 11, characterized in that the inliner (15) is made of an elastic or a rubber-elastic polymer. Inliner according to claim 12, characterized in that the inner wall of the inliner (15) is equipped with an adhesion-minimizing coating and / or is equipped with such a surface structuring.

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