EP1924346B1 - Mixing element for the inversion and mixture of flowing materials in a flow channel, as well as kit and mixer comprising such mixing elements - Google Patents

Abstract

A mixing element (1) inverts and mixes materials flowing in a channel. It has an axially symmetrical base body (1a) with a longitudinal axis (A), an outward-facing surface (1k) and an endface (1m) There are several guide elements (1b) attached at the facing surface by a foot surface to the base body. They have inner (1d) and outer surfaces. Several guide elements are fitted successively circumferentially round the axis.

Description

The invention relates to a mixing element according to the preamble of claim 1. The invention further relates to a kit with mixing elements according to the preamble of claim 11. The invention further relates to a mixer according to the preamble of claim 14.

The documents EP 0063729 and WO 99/00180 disclose a device for inverting and mixing fluids in a tube with at least one mixing element. The mixing element consists of guide surfaces, which are configured such that fluid elements flowing in the center of the pipe are transported to the outside, and fluid elements flowing outward to be transported inward, which is also referred to as a flow inversion or a short inversion. This inversion allows intensive mixing over the entire pipe cross-section, and also improves, if necessary, the heat transfer from a heated or cooled pipe wall and the flowing fluid. The device with mixing elements disclosed in said documents has the disadvantages that it allows only an inverting mixing, and that the mixing elements are made very vulnerable, so that they are easily damaged can be. Particularly disadvantageous is the fact that a long-term reliable operation for a mixer with a plurality of successively arranged mixing elements is not guaranteed, especially if high pressure drops result from the fluid to be mixed in the axial direction.

It is an object of the present invention to propose more advantageous mixing elements, a more advantageous mixer and a more advantageous mixing method.

This object is achieved with a mixing element having the features according to claim 1. The dependent claims 2 to 10 concerning further, advantageously designed mixing elements. The object is further achieved with a kit with mixing elements having the features of claim 11. The dependent claims 12 to 13 relate to further advantageous kits. The object is further achieved with a mixer having the features of claim 14. The subclaims 15 to 19 relate to further, advantageous mixers, in particular dynamic mixer.

The object is achieved in particular with a mixing element for inverting and mixing flowing substances in a flow channel, comprising an axially symmetric base body with a longitudinal axis, wherein the base body has a surface facing outwards with respect to the longitudinal axis and an end face at each end of the longitudinal axis, and comprising a plurality of baffles, which on the surface over a Base surface are fixedly connected to the base body, wherein the guide elements extend obliquely to the longitudinal axis, so that each guide element with respect to the longitudinal axis inwardly facing guide surface and with respect to the longitudinal axis outwardly facing guide surface, and wherein a plurality of guide elements in the circumferential direction of the longitudinal axis successively following are arranged. Depending on the direction of inclination of the guide elements with respect to the longitudinal axis of the flowing material from the outer wall is directed radially inwardly towards the longitudinal axis, or from the inside radially to the outer wall, and thereby mixed the material or the fluid flow in the radial direction. A further mixing takes place behind each web by the resulting between the inflow and outflow of each guide element pressure difference, which leads to vortex formation in the turbulent flow case and in the laminar flow case to a cross flow along the back or the downstream side of the guide element.

The end faces of the mixing elements are configured such that at least two mixing elements in the direction of the longitudinal axis can be arranged in succession such that they touch each other on the end face. Advantageously, the mixing elements on connecting means to mutually connect two mixing elements, and to keep advantageously in a defined, mutual position.

In an advantageous embodiment, the mixing elements have adjacently arranged guide elements in the circumferential direction, which alternately extend at an acute and an obtuse angle to the longitudinal axis, with two circumferentially adjacent guide elements spaced in the direction of the longitudinal axis Foot surfaces have. Between these foot surfaces results in a transverse opening, which causes a transverse flow in the circumferential direction to the longitudinal axis, so that the fluid flowing at least at this point has a cross flow, which generates a further mixing effect. This inventive mixing element thus has at least two different mixing effects, a mixing in the circumferential direction to the longitudinal axis, and, due to the inclined running mixing elements, a mixing in the radial direction to the longitudinal axis.

The mixing elements can be produced in a variety of geometric embodiments, and differently configured, for example, in terms of diameter, number of guide elements, width of the guide elements, or pitch angle of the guide elements. With a kit comprising a plurality of mixing elements designed in this way and comprising a flow channel or a plurality of differently configured flow channels, a large number of different mixers with a wide variety of mixing properties can be assembled. This allows a flexible assembling of mixers, which, depending on the fluid used and the desired mixing behavior, can be assembled differently and thereby optimally adapted to the mixing task to be solved. Under fluid or flowing substances here are liquids, gases or free-flowing solids, as well as single- or multiphase mixtures liquid with the same or strong different viscosities, gaseous and / or solid constituents understood.

In an advantageous embodiment, a plurality of mixing elements on a common carrier, arranged.

It can be distinguished between a static and a dynamic mixer. The static mixer comprises mixing elements which are fixedly and immovably arranged in the mixer. The dynamic mixer comprises mixing elements which are movably arranged in the mixer. In an advantageous embodiment, the mixing elements are mounted within a dynamic mixer about a common axis, in particular rotatable about the longitudinal axis. This rotation causes an additional stretching of the fluid in the circumferential direction or in the direction of rotation of the longitudinal axis.

Fig. 1a

eine Ansicht der Vorderseite eines Mischelementes aus Blickrichtung B;

Fig. 1b

einen Längsschnitt durch das Mischelement gemäss Fig. 1a entlang der Schnittlinie A-A;

Fig. 1c

eine Ansicht der Rückseite des Mischelementes aus Blickrichtung C;

Fig. 1d

eine perspektivische Ansicht der Rückseite;

Fig. 1e

eine perspektivische Ansicht der Vorderseite;

Fig. 2a

eine Ansicht der Vorderseite eines weiteren Mischelementes mit Verstärkungsring auf der Aussenseite;

Fig. 2b

einen Schnitt durch das in Fig. 2a dargestellte Mischelemente entlang der Schnittlinie D-D;

Fig. 3a

eine perspektivische Ansicht eines weiteren Mischelementes;

Fig. 3b

eine Ansicht der Vorderseite des Mischelementes gemäss Fig. 3a;

Fig. 3c

eine Seitenansicht des Mischelementes gemäss Fig. 3a;

Fig. 3d

einen Schnitt durch das in Fig. 3a dargestellte Mischelement entlang der Schnittlinie E-E;

Fig. 3e

eine Draufsicht auf die Oberfläche des Mischelementes gemäss Fig. 3a;

Fig. 4a

eine perspektivische Ansicht eines weiteren Mischelementes;

Fig. 4b

eine Seitenansicht des Mischelementes gemäss Fig. 4a;

Fig. 4c

einen Längsschnitt durch das Mischelement gemäss Fig. 4a entlang der Schnittlinie F-F;

Fig. 5

einen Schnitt durch ein weiteres Ausführungsbeispiel eines Mischelementes;

Fig. 6a

eine perspektivische Ansicht eines Lagerteil bzw. eines Dehnelementes;

Fig. 6b

eine Seitenansicht des Lagerteils bzw. Dehnelementes;

Fig. 6c

einen Längsschnitt durch das Lagerteil bzw. Dehnelementes gemäss Fig. 6b entlang der Schnittlinie G-G;

Fig. 7

einen Längsschnitt durch einen dynamischen Mischer;

Fig. 8

einen Längsschnitt durch ein weiteres Ausführungsbeispiel eines dynamischen Mischers;

Fig. 9

einen Längsschnitt durch ein weiteres Ausführungsbeispiel eines Mischers;

Fig. 10 bis 13

je einen Querschnitt durch den Mischer gemäss Fig. 9 entlang der Schnittlinie H-H mit Ausführungsbeispielen von Mischelementen;

Fig. 14a bis 14c

je einen Abschnitt eines Längsschnittes durch einen dynamischen Mischer mit drehbarem Mischelement und statischem Lager- bzw. Dehnelement;

Fig. 15a bis 15e

je einen Abschnitt eines Längsschnittes durch einen dynamischen Mischer mit drehbarem Mischelement und feststehenden Dehnelementen;

Fig. 16a

eine Ansicht der Vorderseite eines weiteren Mischelementes;

Fig. 16b

eine Seitenansicht des Mischelementes gemäss Fig. 16a;

Fig. 16c

eine Ansicht der Vorderseite eines Mischers umfassend eine Mehrzahl der in Figur 16a dargestellten Mischelemente;

Fig. 17

eine Ansicht der Vorderseite eines weiteren Mischelementes;

Fig. 18

eine Anordnung von Mischelementen in einem rechteckigen Strömungskanal;

Fig. 19a bis 19c

Querschnitte durch unterschiedliche Leitelemente.

The invention will be described below in more detail with reference to several embodiments, which represent only a selection of a plurality of possible embodiments. Show it:

Fig. 1a

a view of the front of a mixing element from the direction B;

Fig. 1b

a longitudinal section through the mixing element according to Fig. 1a along the section line AA;

Fig. 1c

a view of the back of the mixing element from the direction of view C;

Fig. 1d

a perspective view of the back;

Fig. 1e

a perspective view of the front;

Fig. 2a

a view of the front of another mixing element with reinforcing ring on the outside;

Fig. 2b

a cut through the in Fig. 2a illustrated mixing elements along the section line DD;

Fig. 3a

a perspective view of another mixing element;

Fig. 3b

a view of the front of the mixing element according to Fig. 3a ;

Fig. 3c

a side view of the mixing element according to Fig. 3a ;

Fig. 3d

a cut through the in Fig. 3a illustrated mixing element along the section line EE;

Fig. 3e

a plan view of the surface of the mixing element according to Fig. 3a ;

Fig. 4a

a perspective view of another mixing element;

Fig. 4b

a side view of the mixing element according to Fig. 4a ;

Fig. 4c

a longitudinal section through the mixing element according to Fig. 4a along the section line FF;

Fig. 5

a section through another embodiment of a mixing element;

Fig. 6a

a perspective view of a bearing part or an expansion element;

Fig. 6b

a side view of the bearing part or expansion element;

Fig. 6c

a longitudinal section through the bearing part or expansion element according to Fig. 6b along the section line GG;

Fig. 7

a longitudinal section through a dynamic mixer;

Fig. 8

a longitudinal section through another embodiment of a dynamic mixer;

Fig. 9

a longitudinal section through a further embodiment of a mixer;

Fig. 10 to 13

depending on a cross section through the mixer according to Fig. 9 along the section line HH with embodiments of mixing elements;

Fig. 14a to 14c

each a portion of a longitudinal section through a dynamic mixer with rotatable mixing element and static bearing or expansion element;

Fig. 15a to 15e

each a portion of a longitudinal section through a dynamic mixer with rotatable mixing element and fixed expansion elements;

Fig. 16a

a view of the front of another mixing element;

Fig. 16b

a side view of the mixing element according to Fig. 16a ;

Fig. 16c

a front view of a mixer comprising a plurality of in FIG. 16a illustrated mixing elements;

Fig. 17

a view of the front of another mixing element;

Fig. 18

an arrangement of mixing elements in a rectangular flow channel;

Fig. 19a to 19c

Cross sections through different guide elements.

Fig. 1a shows a view of the front of a mixing element 1, as in FIG. 1b represented, viewing direction B. The mixing element 1 consists of a respect to an axis A axisymmetric base body 1a, which in the illustrated embodiment is cylindrical and thus rotationally symmetrical. In the circumferential direction A1 to the axis A nine guide elements 1b are arranged evenly spaced and firmly connected to the base 1a. The distance between two guide elements 1b is the angle γ, and the width of a guide element 1b is one Angle β, wherein the angle β is half the angle γ. The main body 1a has a flat, perpendicular to the axis A extending end face 1m, wherein above three connecting means 1n are arranged, of which the left and right arranged connecting means 1n are designed as a cylindrical bore, and the middle connecting element 1n as a cylindrical protruding part. At the rear end face 1m are below three dashed lines connecting means In arranged.

FIG. 1b shows a longitudinal section through the mixing element 1 along the section line AA, which, as in FIG. 1a shown, also through the cylindrical bore 1n runs. On the surface A 1 facing outwards with respect to the axis A, the guide elements 1 b extending obliquely to the axis A are arranged in the upward direction. The guide elements 1b extend with respect to the axis A at an angle α. The guide elements 1b thus have a guide surface 1d facing inwards with respect to the axis A and a guide surface 1c pointing outwards relative to the axis A. In addition, on the two opposite end faces 1m, the connecting means In are shown, wherein on the left both the protruding cylindrical connecting means 1n and the cylindrical bore 1n are visible.

Figure 1c shows a view of the back of the mixing element 1, as in FIG. 1b shown, viewing direction C. Figure 1d shows a perspective view of the back of the mixing element 1, and Figure 1e a perspective view of the front of the mixing element 1. It is again the cylindrical base body 1a shown, with the axis A, and arranged on the surface 1k of the base body 1a in the circumferential direction A1 spaced Guide elements 1b. On both end faces 1m, the connecting means In can be seen. Several mixing elements 1 can be arranged successively in the axial direction A with abutting end faces 1m, such that the connecting means In interlock, so that the mutual position of the individual mixing elements 1 in the circumferential direction A1 is defined.

FIG. 2a shows a view of the back of another embodiment of a mixing element 1. In contrast to the in FIG. 1a shown mixing element 1 has the in FIG. 2a illustrated mixing element 1 an annular support structure 1o, which is fixedly connected to the outer ends of the guide elements 1b. FIG. 2b shows a longitudinal section through the mixing element 1 according FIG. 2a along the section line DD. The guide element 1b has with respect to the axis A an inclined α at an angle course, wherein the ends of the guide element 1b open either in the main body 1a or in the support structure 1o. At the two opposite end faces 1m connecting means are arranged In. An advantage of in the FIGS. 2a and 2b shown mixing elements 1 can be seen in the fact that a plurality of such mixing elements 1 in the direction of the axis A lying side by side and can be arranged touching each other, so that a tubular mixer is formed, wherein the support structure 1o forms the outer boundary. The support structure 1o could have ring-shaped sealing means on its end faces 1m, so that two mixing elements 1 arranged adjacently in the direction of the axis A are sealed radially to the axis A in the region of the support structure 10.

The mixing elements 1 can also be installed without special sealing in a flow channel, for example a pipe, wherein between the inner wall of the flow channel and the outer diameter of the mixing element 1 is preferably only a small gap. This in FIGS. 2a and 2b illustrated mixing element has the advantage that each individual guide element 1b is connected at both ends with a support structure, namely in each case both with the base body 1a and with the annular support structure 1o. This arrangement thus has the property that the forces acting on the guide element 1b during mixing forces are distributed to two discharge points, inside the base 1a and the outside of the support structure 1o. As a result, the individual guide elements 1b can be loaded higher without any deformation or even destruction occurring. Such arranged guide elements 1b can thus withstand greater forces acting, both axially in the direction of the longitudinal axis A and radially to this. Thus, a larger pressure drop of the fluid in the axial direction is possible without there being a risk of destruction for the guide elements 1b. Such arranged guide elements 1 b can also be configured with reduced wall thickness, which either reduces the resulting pressure drop at a constant fluid throughput, or allows a higher fluid throughput at the same pressure drop.

FIG. 3a shows a perspective view of another embodiment of a mixing element 1. On the cylindrical base body 1a with axis A in turn in the circumferential direction 1a, a plurality of guide elements 1b are arranged, wherein in the circumferential direction A1 adjacent guide elements 1b alternately at an acute and an obtuse angle go to the axis A. The guide elements 1b in turn have with respect to the axis A outwardly facing guide surfaces 1c and with respect to the axis A inwardly facing guide surfaces 1d. The guide elements 1b also have an outer edge 1i. In the illustrated embodiment, the general flow direction S of the fluid in the direction of the axis A, so that designated 1c and 1d surfaces of the guide elements 1b are assigned to the upstream side, whereas the other, non-visible surface of these guide elements 1b are assigned to the downstream side. The assignment to inflow side and outflow side of course depends on the flow direction S.

FIG. 3e shows a plan view of a development of the surface 1k, wherein the guide elements 1b are cut in the region of the foot surfaces 11. The foot surfaces 11 of guide elements 1 b arranged adjacent in the circumferential direction A1 are arranged at a distance in the direction of the axis A, so that a transverse opening 1e extending transversely to the axis A is formed between adjacently arranged guide elements 1b. The guide element 1b arranged at the top also has a triangular flow divider 1f projecting counter to the flow direction S, so that the guide element 1b is flowed around on both sides by the fluid flowing in the direction S, which, with respect to the axis A, effects thorough mixing of the fluid in its circumferential direction ,

FIG. 3b shows a view of the front of the in FIG. 3a 1. The guide elements 1b have side edges running radially to the axis A, wherein each guide element 1b has an angular width β of 30 °, so that these side edges appear to lie next to one another in this view. The in this View of an inwardly directed guide surface 1d having guide elements 1b also have the visible flow parts 1f on. The other guide elements 1b, which in the illustrated view have no flow divider 1f, have an outwardly oriented guide surface 1c. In the circumferential direction A1 adjacent guide elements 1b have, as in FIGS. 3a and 3e represented, in the direction of the axis A spaced feet 11, so that between two adjacent guide elements 1b, the transverse opening 1e results.

Figure 3c shows a side view of the mixing element 1 according FIG. 3a , The total length L2 of the mixing element 1 is several times longer than the total length L1 of the part provided with baffles 1b. The mixing element 1 has an outer diameter D2. The main body 1a has an outer diameter D1.

3d figure shows a longitudinal section through the in Figure 3c illustrated mixing element 1 along the section line EE. In this exemplary embodiment, adjacently arranged guide elements 1b are firmly connected to one another via a web at the contact point 1h, so that a transverse opening 1e defined by the two adjacent guide elements 1b and the surface 1k of the main body 1a forms between the surface 1k and the contact point 1h. Two adjacent guide elements 1b could also touch each other only at the contact point 1h without mutually fixed connection. The guide elements 1b could also be made narrower in the circumferential direction A1, so that adjacent guide elements 1b do not touch, but at the point with the smallest mutual distance form a point 1h.

FIG. 4a shows a further mixing element 1, which, in contrast to the embodiment according to FIG. 3a , Has a hollow cylindrical body 1a. The inner surface of the hollow cylindrical base body 1a could also have a toothing, for example a groove lq arranged on the inner surface, which allows the mixing element 1 to be firmly connected, for example, to a stationary or driven shaft with external toothing. Preferably, a plurality of mixing elements 1 are successively arranged on such a shaft in the longitudinal direction, wherein their mutual position, in particular of adjacent mixing elements, can be determined exactly. Such a shaft equipped with mixing elements 1 can be used for example as a worm shaft of an extruder. FIG. 4b shows a side view of the in FIG. 4a shown mixing element 1, and Figure 4c shows a longitudinal section through the mixing element 1 along the cutting plane FF.

FIG. 5 shows a longitudinal section along the sectional plane FF by a further embodiment of a mixing element 1. By an appropriate choice of inner and outer diameter D1, D2 and the lengths L1, L2, the inclination angle α between axis A and direction of the guide element 1b as required in a Range between 10 ° and 85 ° be selected.

FIG. 6a shows a perspective view of a bearing part or expansion part 2 consisting of a hollow cylindrical bearing 2a, and a plurality of extending in the radial direction support arms 2b, the cross-sectional shape may be arbitrary, and which may act as expansion elements at the same time. FIG. 6b shows a front view of the bearing part or expander 2, and FIG. 6c a section along the Section plane GG. The bearing part 2 can be fixedly arranged in a flow channel 5a, and preferably serve as a bearing for a rotatable shaft. However, the part 2 can also be firmly connected to a rotatable shaft, so that this part 2 is rotatably disposed within the flow channel 5a, and by this rotation causes a stretching of the fluid in the circumferential direction to the axis A, which is why this part is also referred to as a stretch part 2 , The course of the axis A corresponds to the course of the rotatable shaft.

FIG. 7 shows a longitudinal section of a dynamic mixer 5, comprising a cylindrical flow channel 5a, a plurality of spaced apart in the direction of the axis A and with the flow channel 5a via fastening means 2c connected bearing parts 2, in which a plurality of in the direction of the axis A juxtaposed mixing elements 1 are rotatably mounted at bearings 1p. The mixing elements 1 are mutually fixedly connected to one another via connection means 1n which are visible in the light, and thus form an assembled mixing element 3. The assembled mixing element 3 comprises on both sides a conical cover 3a, between which the individual mixing elements 1 are clamped. The assembled mixing element 3 also comprises on one side a projecting, rotatable shaft 4, which can be set in rotation from the outside. Two inlets 6a, 6b are supplied to the mixer 5, so that the fluid flowing through these inlets 6a, 6b flows through the mixer 5 and is then supplied to the outlet 6c. In FIG. 7 only the upper part of the assembled mixing element 3 is shown in section. The rotating mixing elements 1 in particular cause a rotation of the fluid in the circumferential direction to the axis A, wherein the bearing parts 2 are fixed, and thus on the rotating fluid exert a stretching action in the circumferential direction.

The in FIG. 7 shown mixer is particularly suitable as a so-called dynamic inline mixer, especially for fluids with different viscosities, from gaseous to highly viscous fluids. The mixer is suitable, for example, for mixing reactive resin / hardener systems, for mixing components of polyurethane systems, for food preparation, for dispersing liquids with strong differences in viscosity, such as additives in plastic melts, or for dispersing gases in liquids.

FIG. 8 shows in a longitudinal section a further embodiment of a dynamic mixer 5, wherein, in contrast to the embodiment according to FIG. 7 , the bearing parts 2 also as mixing elements 1, for example as in FIG. 4a are shown, are configured, these mixing elements 1 are connected via fastening means 2c fixed to the outer wall of the mixer 5, and wherein the assembled mixing element 3 is rotatably mounted in these fixedly arranged mixing elements 1.

FIG. 9 shows in a longitudinal section a static mixer 5 with a tubular flow channel 5a, in the interior of an assembled mixing element 3 is fixedly arranged. The mixing element 3 is fixedly connected to the outer wall or the flow channel 5a via fastening means, not shown, 2c. An advantage of the mixing elements 1 according to the invention lies in the fact that they can be assembled in a very wide variety of ways, wherein preferably also spacer elements 7 can be used, for example, which are cylindrical in shape and have the same connection points in as the mixing elements 1. Such mixing elements 1 are particularly suitable for use as a kit in order to produce mixers 5 with differently configured, assembled mixing elements 3. FIG. 9 shows on the basis of several arrangement examples, how a mixing element 3 can be assembled by different combination of mixing elements 1 and possibly using spacers 7.

The FIGS. 10 to 13 show the section 5b from a view in the direction of the cutting plane HH. Depending on the configuration of the mixing elements 1 arranged within the section 5b on the left and on the right, different cross-sections result. In FIG. 10 For example, each mixing element 6 has guide elements 1 b which have an angular width β of 30 ° each, with adjacent guide elements 1 b being offset by 30 ° in the circumferential direction A1. The two mixing elements 1 are arranged offset in the circumferential direction A1, that the guide elements 1b, similar to in FIG. 3b are arranged shown. In section 5b, a spacer element 7 is arranged between the mixing elements 1. The mixing elements 1 could also, as shown in section 5c, without the use of a spacer element 7 mutually adjoining the end faces 1m be arranged, the guide elements 1b of a mixing element 1 come to lie in the interstices of the other mixing element 1, if the main body 1a, as shown, are designed according to short. The mixing element 1 arranged in section 5c could also be made in one piece, as in FIG FIG. 3a represented, be configured.

The guide elements 1b could also have parallel side ends, as in the section according to FIG. 11 is shown, in this embodiment, all the guide elements 1b of both mixing elements 1 in the circumferential direction A1 have the same width.

Differently designed mixing elements 1 can be combined in any way in section 5b. On average according to FIG. 12 this is a mixing element 1 as in FIG. 10 illustrated configured, whereas the other mixing element 1 as in FIG. 11 is shown configured so that their arrangement in section 5b according to FIG. 12 shown sectional view shows.

Two mixing elements 1, in particular two identical mixing elements 1, could also be arranged mutually offset in the circumferential direction A1, as in the sectional view according to FIG FIG. 13 is shown in which the in FIG. 10 shown two mixing elements 1 are mutually rotated in the direction A1, for example, such that the left in section 5b shown mixing element 1 with vanes 9 retains its position, whereas the mixing element 1 shown in section 5b right with guide element 8 is rotated in the direction A1, so that from the perspective of the sectional plane HH, a part of the guide element 8 comes to lie behind the guide element 9.

Figure 14a shows in a longitudinal section a mixer 5 with a cylindrical flow channel 5a wherein two mixing elements 1 are arranged on the rotatable shaft 4, and the rotatable shaft 4 is rotatably supported via a bearing part 2 or expansion part 2. The bearing part 2 or expansion part 2, with the aid of a fastening means 2 c, for example a screw, fixed to the Flow channel 5a connected. However, the support arms 2b of the bearing part 2 can also be pressed against the inner surface of the flow channel 5a and held so firmly. In the longitudinal sections according to the Figures 14b and 14c the bearing parts 2 are designed as mixing elements 1, for example as in Figure 4a or 4c shown. These bearing parts 2 or 2 stretched parts are connected via fastening means 2c fixed to the flow channel 5a.

The FIGS. 15a to 15e show longitudinal sections of mixers 5 with rotatably mounted mixing elements 1. Die FIGS. 15a to 15d show in the interior of the flow channel 5a projecting expansion elements 10, which are configured, for example, cylindrical or rhombic. The expansion elements 10 may be configured in various ways, for example, as in FIG. 15e illustrated, also in such a way that the expansion element 10 has an outer circumferential ring on which inwardly projecting guide elements 10a are arranged. The guide elements 10a could, as in FIG. 15e shown, crossed.

FIG. 16a shows the back of another embodiment of a mixing element 1 with respect to an axis A axisymmetric base body 1a and projecting guide elements. FIG. 16b shows in a side view from direction I the in FIG. 16a illustrated mixing element. 1

FIG. 17 shows the back of another mixing elements 1 with hexagonal base 1a and three protruding guide elements 1b.

FIG. 18 shows a cross section through a mixer 5 with rectangular flow channel 5a. In the flow channel 5a three mixing elements 1 are arranged parallel and next to each other. Behind the visible mixing elements 1, a plurality of further mixing elements 1 could be arranged perpendicular to the plane of representation.

The FIGS. 19a to 19c show cross sections through guide elements 1b. The guide elements 1b can be configured with a wide variety of cross-sectional shapes.

The illustrated mixing elements 1 and mixer 5 are suitable for mixing, homogenizing and dispersing a variety of fluids, in particular for melt homogenization in injection molding or extrusion. The mixing elements 1 and mixer 5 are thus also suitable for use as mixing parts on screws of extruders, e.g. for the processing of plastics or food, or for injection molding machines. The mixing elements 1 and mixer 5 could also be installed in the backstops of injection molding machines and complement the function of this machine part by the mixing function. The mixers 5 according to the invention can also be used when the fluid to be mixed is subject to greater alternating loads, since larger forces can be transmitted to one another between the individual mixing elements 1, via their end faces 1m.

The pressure drop across a mixing element 1 can in particular also be influenced by the angle of inclination α of the guide element 1b. In order to obtain a lower pressure drop, the inclination angle α is chosen to be smaller. Accordingly a larger inclination angle α leads to a larger pressure drop. The pressure drop can also be influenced by an appropriate choice of the length of the mixing element 1 in the axial direction A or by an appropriate choice of the shape of the guide elements 1 b or a corresponding width β of the guide elements 1 b.

The mixing elements 1 can be made of a wide variety of materials, such as metal or plastic. They can be produced or assembled by means of suitable casting processes, of solid material by means of chip removal processes, by means of electro-erosion or laser cutting processes, by reshaping or by assembly from individual shaped parts which are produced by welding, soldering, gluing, gearing or other suitable joining processes.
Due to the modular design of the mixers of individual mixing elements, these can be easily disassembled if necessary, eg for cleaning or for inspection.

Depending on its configuration, the mixer according to the invention allows a static or, in the case of the use of movable, rotatable parts, a dynamic mixing. In static mixing, the mixing process is carried out by continuously dividing the fluid stream into substreams which are rearranged and reassembled. The rearrangement can take place, essentially, radially to the axis A or in the circumferential direction to the axis A. A distributive mixing process. There are limits to this mixing process, for example in the case of dispersing tasks, in which the necessary energy input increases sharply when fine dispersions are to be produced. For such applications, it is more advantageous to use a mixing method use, which is based on the principle of stretching a fluid flow, which allows a much better mixing with less energy. The example in the FIGS. 7 and 8th described dynamic mixer combines the two mixing principles splitting (and stretching in an ideal way.

In an advantageous method for mixing a flowing substance in a flow channel having a longitudinal axis A, the flowing substance is distributed with a static mixing element with respect to the longitudinal axis A both in the radial direction and in the circumferential direction, and the flowing substance with a dynamic mixing element 2, which is rotated about the longitudinal axis A, stretched in the circumferential direction. In a further advantageous method step, the dynamic mixing element will distribute the flowing substance with respect to the longitudinal axis (A) at least in one of the two directions: radial direction and circumferential direction.

Depending on the degree of difficulty of the mixing task and the demands on the degree of homogeneity of the mixture to be achieved, between 1 to 100 mixing elements arranged one behind the other are required, possibly even more.

Claims (19)

1. A mixing element (1) for the inversion and mixing of flowing materials in a flow channel including a base body (1a) having a longitudinal axis (A) and including a plurality of guiding elements (1b) which are fixedly connected to the base body (1a), wherein the guiding elements (1b) extend obliquely to the longitudinal axis (A) so that each guiding element (1b) has an inwardly facing guiding surface (1d) with respect to the longitudinal axis (A) and an outwardly facing guiding surface (1c) with respect to the longitudinal axis (A) and wherein a plurality of guiding elements (1b) are arranged following one another in the peripheral direction (A1) of the longitudinal axis (A), characterized in that the base body (1a) is of axially symmetrical design, extends in the direction of the longitudinal axis (A) and ends at both sides with an end face (1m) extending perpendicular to the longitudinal axis (A); in that the base body (1a) has a surface (1k) facing outwardly with respect to the longitudinal axis (A); and in that the guiding elements (1b) are fixedly connected to the surface (1k) via a foot area (11); and in that the base body (1a) has a length in the direction of the longitudinal axis (A) such that at least two mixing elements can be arranged following one another in the direction of extent of the longitudinal axis (A) such that they contact one another at their end faces (1m).
2. A mixing element in accordance with claim 1, characterized in that the guiding elements (1b) are uniformly spaced in the peripheral direction (A1) and in that the intermediate space between two guiding elements (1b) corresponds at least to the width of a guiding element in the peripheral direction (A1).
3. A mixing element in accordance with one of the preceding claims, characterized in that the end faces (1m) have connecting means (1n) in order to connect mixing elements (1) arranged adjacent to one another in the direction of the longitudinal axis (A).
4. A mixing element in accordance with claim 3, characterized in that the connection means (1n) have a plurality of engagement positions spaced apart in the peripheral direction (A1).
5. A mixing element in accordance with one of the preceding claims, characterized in that the guiding elements (1b) have two lateral ends which extend radially to the longitudinal axis (A).
6. A mixing element in accordance with one of the claims 1 to 4, characterized in that the guiding elements (1b) have two lateral ends which extend in parallel.
7. A mixing element in accordance with one of the preceding claims, characterized in that the outer ends of the guiding elements (1b) are connected to a common support structure (10) .
8. A mixing element in accordance with one of the preceding claims, characterized in that adjacent guiding elements (1b) in the peripheral direction (A1) alternatingly extend at an acute angle and at an obtuse angle to the longitudinal axis (A), with in each case two adjacent guiding elements (1b) in the peripheral direction (A1) having foot areas (11) which are spaced apart in the direction of the longitudinal axis (A).
9. A mixing element in accordance with claim 8, characterized in that in each case two adjacent guiding elements (1b) in the peripheral direction (A1) form a contact point (1h) above the surface (1k) of the base body (1a) so that a transverse opening (1e) bounded by the two adjacent guiding elements (1b) and the surface (1k) of the base body (1a) is formed between the surface (1k) and the point of contact (1h), with an even multiple of guiding elements (1b) being arranged in the peripheral direction (A1).
10. A mixing element in accordance with one of the preceding claims, characterized in that the base body (1a) is of cylindrical shape.
11. A set of components comprising a plurality of mixing elements (1) in accordance with one of the preceding claims.
12. A set of components in accordance with claim 11, including spacer elements (7) which have an axially symmetric base body (1a) with end faces (1m) but no guiding elements (1b), with the spacer elements (7) being intended to be arranged between mixing elements (1).
13. A set of components in accordance with one of the claims 11 or 12, including mixing elements (1) and/or spacer elements (7) which form a circular support point (1p) in cross-section.
14. A mixer (5) including a flow passage (5a) and also mixing elements (1) in accordance with one of the claims 1 to 10 or including a flow passage (5a) and a set of components in accordance with one of the claims 11 or 13.
15. A mixer (5) including a flow passage (5a) and also a plurality of mixing elements (1) in accordance with one of the claims 1 to 10 arranged therein on a common carrier.
16. A mixer in accordance with claim 15, characterized in that the mixing elements (1) are rotatably mounted about the longitudinal axis (A).
17. A mixer in accordance with claim 16, characterized in that the support parts (2) fixedly connected to the flow passage (5a) and having mixing elements (1) form a rotary bearing.
18. A mixer in accordance with claim 17, characterized in that the bearing parts (2) have a plurality of support arms (2b) extending in the radial direction which are fixedly connected to the flow passage (5a) or in that the bearing parts (2) are fixedly connected to the common carrier and jointly form an extension element (2) together with the support arms (2b).
19. A mixer in accordance with claim 17, characterized in that the bearing parts (2) are formed as mixing elements (1) having a plurality of guiding elements (1b) arranged distributed in the peripheral direction (A1).

Images