Static mixer

Abstract

A mixing element for a static mixer for installation into a tubular mixer housing has a longitudinal axis along which a plurality of installation bodies are arranged behind one another.

Claims

1. A mixing element for a static mixer configured to be installed into a tubular mixer housing, comprising: a plurality of installation bodies arranged in series along a longitudinal axis of the mixing element including a first installation body having a first wall element extending in a direction of the longitudinal axis, a first side wall and a second side wall arranged opposite the first side wall, a deflection element arranged adjacent to the first wall element, the deflection element having a deflection surface extending in a transverse direction to the first wall element at both sides of the wall element, the deflection surface having a first opening at a side facing the first side wall of the first wall element, a second wall element and a third wall element arranged adjacent to the first opening, the second and third wall elements extending in the direction of the longitudinal axis, each of the second and third wall elements having an inner wall and an outer wall extending substantially in the direction of the longitudinal axis, each of the inner walls and outer walls including an angle between 20 and 160 with one of the first and second side walls of the first wall element, the first opening of the deflection surface being arranged between the inner walls of the second and third wall elements, a second opening arranged outside one of the outer walls of one of the second and third wall elements, the second opening being disposed on the deflection surface at a side facing the second side wall of the first wall element, a first wall element of a second installation body adjoining the second and third wall elements, the first installation body being connected to the second installation body via a common bar element; and at least two separation elements connected to the bar element, the separation elements being located next to one another with respect to the longitudinal axis of the mixing element, and being formed as a projection extending only partially circumferentially around an inner wall of the mixer housing, each separation element of the separation elements defining a plane that is substantially perpendicular to the bar element.

2. The mixing element in accordance with claim 1, wherein each of the separation elements is formed as one of a strip and a rib having an angle, at least partly, of more than 45 with respect to the longitudinal axis of the mixer.

3. The mixing element in accordance with claim 1, wherein each of the separation elements is one of a strip and a rib.

4. The mixing element in accordance with claim 1, wherein a free cross-sectional area of the mixer housing is reduced by 5 to 12.5% by the separation elements.

5. The mixing element in accordance with claim 1, wherein a wall thickness of each of the separation element differs by a maximum of 10% of a mean wall thickness of one of the wall elements and the deflection elements.

6. The mixing element in accordance with claim 5, further comprising the plurality of separation elements are arranged along the longitudinal axis of the mixing element such that a distance between adjacent pairs of separation elements is not equal to a distance between subsequent pairs of adjacent separation elements.

7. The mixing element in accordance with claim 1, wherein each of the separation elements is one of a strip and a rib extending at least partly at an inner wall of the bar element.

8. The mixing element in accordance with claim 7, wherein the deflection element is one of a plurality of deflection elements, the bar element is one of a plurality of bar elements, and each of the separation elements is a strip extending from a respective bar element to a respective deflection element.

9. The mixing element in accordance with claim 1, wherein each of the separation elements has an arm projecting into the mixer space.

10. The mixing element in accordance with claim 8, wherein each of the separation elements is connected to the respective bar element and to the respective deflection element.

11. The mixing element in accordance with claim 8, wherein a first bar element and a second bar element of the plurality of bar elements are connected to one another via one of the separation elements.

12. The mixing element in accordance with claim 1, wherein the second installation body has the first wall element extending in the direction of the longitudinal axis, the second installation body having a first side wall and a second side wall arranged opposite the first side wall, a deflection element being arranged adjacent to the first wall element and the deflection element having a deflection surface extending in the transverse direction to the wall element at both sides of the wall element, the deflection surface of the second installation body having a first opening at a side of the deflection surface facing the second side wall of the wall element, a second wall element and a third wall element being arranged adjacent to the first opening and extending in the direction of the longitudinal axis, each of the second and third wall elements having an inner wall and an outer wall extending substantially in the direction of the longitudinal axis, each of the inner walls and outer walls including an angle between 20 and 160 with the first or second side walls of the first wall element, the first opening of the deflection surface being arranged between the inner walls of the second and third wall elements and a second opening being arranged outside one of the outer walls of the second or third wall elements, the second opening is provided in the deflection surface of the second installation body at side facing the second side wall of the first wall element, the second installation body containing the first wall element, the deflection element and the second and third wall elements being rotatably arranged about the longitudinal axis by an angle between 10 and 180 with respect to the first installation body.

13. The mixing element in accordance with claim 12, wherein the second installation body has the same structure as the first installation body.

14. The mixing element in accordance with claim 12, wherein the bar element is arranged at an outer periphery of the deflection element.

15. The mixing element in accordance with claim 4, wherein the free cross-sectional area of the mixer housing is reduced by 5% to 10% by the separation elements.

16. The mixing element in accordance with claim 5, wherein the wall thickness of the separation elements differs by a maximum of 5% of the mean wall thickness of one of the wall elements and the deflection elements.

17. The mixing element in accordance with claim 13, wherein the first installation body is rotatably arranged rotated about the longitudinal axis by an angle of 180 with respect to the second installation body.

18. The mixing element in accordance with claim 1, wherein each of the separation elements is an arcuate strip having a wall thickness that is less than a length extending in a circumferential direction of the strip.

19. The mixing element in accordance with claim 18, wherein the bar element is one of a plurality of bar elements, and each of the separation elements is a prolongation of a respective bar element.

20. A static mixer comprising the mixing element in accordance with claim 1 and further comprising a mixer housing surrounding the mixing element.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1 an embodiment of a detail of a mixing element in accordance with a first embodiment of the invention;

(2) FIG. 2a an embodiment of a detail of a mixing element in accordance with a second embodiment of the invention with a separation element in accordance with a first variant;

(3) FIG. 2b an embodiment of a detail of a mixing element in accordance with a second embodiment of the invention with a separation element in accordance with a second variant;

(4) FIG. 2c an embodiment of a detail of a mixing element in accordance with a second embodiment of the invention with a separation element in accordance with a third variant;

(5) FIG. 2d an embodiment of a detail of a mixing element in accordance with a second embodiment of the invention with a separation element in accordance with a fourth variant;

(6) FIG. 3 a view of a mixing element with installation bodies in accordance with FIG. 2,

(7) FIG. 4 a section through an installation body in accordance with FIG. 2,

(8) FIG. 5 a section through the installation body which is arranged adjacent to the installation body in accordance with FIG. 4; and,

(9) FIG. 6 a section through an inlet part of a static mixer and mixing element in accordance with FIG. 3.

DETAILED DESCRIPTION

(10) An embodiment of a mixing element 100 for a static mixer in accordance with a first embodiment of the invention is shown in FIG. 1. The mixing element includes an installation body 1 which is installed in a tubular housing which is not shown. The tubular housing serves as a boundary of a mixing space 20 which is located in the interior of the tubular housing. A fluid to be mixed, which is as a rule made up of at least two different components, flows through the mixing space 20. In most cases, the components are present in the fluid state or as viscous materials. These include, for example, pastes, adhesives, but also fluids which are used in the medical sector which include pharmaceutical agents or fluids for cosmetic applications and foods. Such static mixers are also in particular used as disposable mixers for the mixing of a hardening mixing product of flowable components such as the mixing of multicomponent adhesives. Another preferred use is in the mixture of impression materials in the dental field.

(11) The mixing element in accordance with FIG. 1 thus includes an installation body 1 for installation into a tubular mixer housing, with the installation body 1, 101 having a longitudinal axis 10 which is aligned in the direction of a fluid flowing into the installation body 1. A mixing space 20 which is bounded at the peripheral side by a mixer housing, not shown, can be spanned by the installation body 1. A cubic mixing space is indicated in FIG. 1 to facilitate understanding. The side surfaces of the cube can represent the inner walls of the mixer housing. The fluid flows from the top surface of the cube, which forms a cross-sectional flow area 22, in the direction of the installation body 101.

(12) The installation body 1 and the installation body 101 have the same structure; however, the installation body 101 is rotated by 180 about the longitudinal axis 10. Like the mixing space 20, the mixing space 120 has a cross-sectional flow area 122 in a plane 121 arranged normal to the longitudinal axis 10 which essentially corresponds to the cross-sectional flow area of the tubular mixer housing surrounding the installation body 101. For installation bodies 1, 101 which have at least one plane of symmetry which divides the mixing space into two equal parts, the longitudinal axis is disposed in this plane of symmetry. The mixing space is bounded by the mixer housing, not shown. In this embodiment, the mixing element should be installed into a mixer housing have a rectangular or quadratic cross-section. The inner dimension of the mixer housing which is used for determining the equivalent diameter is given by reference line 36.

(13) The installation body 1 contains at least one first wall element 2 which serves a division of the fluid flow into two part flows flowing substantially parallel to the longitudinal axis 109. The wall element 2 has a first side wall 3 and a second side wall 4. The intersection of the first wall element 2 with the plane 21 produces a cross-sectional area 23. This cross-sectional area 23 amounts to a maximum of , preferably a maximum of 1/10, particularly preferably a maximum of 1/20, of the cross-sectional flow area 22 of the mixing space 20 without installation bodies. The fluid thus flows at both sides of the side walls 3, 4 of the wall element 2. The flow direction of the fluid is indicated by an arrow. The wall element has a substantially rectangular cross-section. The first wall element 2 has a first wide side 5, a second wide side 6 as well as a first and second long side 25, 35. The first wide side 5, the second wide side 6, the first long side 25 and the second long side 35 form the periphery of each of the side walls 3, 4. The long sides 25, 36 extend substantially in the direction of the longitudinal axis 10 and the first wide side 5 and the second wide side 6 extend transversely to the direction of the longitudinal axis. The first wall element 2 divides the mixing space into two parts. The wall element 2 has the function of a bar element which divides the fluid flow into two parts, with their deflection being negligible with the exception of the deflection at the edges of the first wide side 5. The wall thickness 7 of the wall element 2 usually amounts to less than 1 mm for a mixing element with a total length of up to 100 mm.

(14) A deflection element 11 which serves for the deflection of the part flows in a direction differing from the longitudinal axis adjoins the first wall element 2. The deflection element has a deflection surface extending in the transverse direction to the wall element 2 at both sides of the wall element. A first opening 12 is provided in the deflection surface at the side which faces the first side wall 3 of the wall element 2.

(15) The crossing angle between the first wall element 2 and the second or third wall element 8, 9 respectively amounts to 90 in the embodiment in accordance with FIG. 1. In accordance with FIG. 1, the first wall element 2 is connected to the second wall element 8 and to the third wall element 9 via the deflection element 11. The deflection element 11 is preferably disposed in a plane which is aligned parallel to the plane 21 or is arranged at an angle of inclination with respect to the plane, with the angle of inclination amounting to no more than 60, preferably no more than 45, particularly preferably no more than 30. The smaller the angle of inclination between the surface of the deflection element 11 and the plane 21, the smaller the required construction length. Or in other words: the surface of the deflection element 11 is substantially disposed in a transverse plane which is aligned at an angle of 45 up to 90, preferably of 60 up to 90, particularly preferably of 75 up to 90, to the longitudinal axis 10.

(16) The wall elements 8, 9 adjoining the deflection element 11 bound a passage which starts from the first opening 12 and extends in the direction of the longitudinal axis 10. It is meant by the expression adjoining the deflection element that the second and third wall elements 8, 9 are arranged opposite the first wall element 2 in the direction of the longitudinal axis, that is are arranged downstream of the first wall element 2 in the direction of flow.

(17) A second opening is provided in the deflection surface at the side which faces the second side wall 4 of the wall element 2, with the second or third wall elements 8, 9 adjoining the second opening. The second and third wall elements 8, 9 bound the same passage which also starts from the first opening 12.

(18) A second and a third wall element 8, 9 are thus arranged adjacent to the first opening 12. The second and third wall elements 8, 9 extend in the direction of the longitudinal axis 10 and each have an inner wall 81, 91 and an outer wall 82, 92 which extend substantially in the direction of the longitudinal axis 10. The second wall element 9 has the inner wall 81 and the outer wall 82. The third wall element 91 has the inner wall 91 and the outer wall 92. In the present embodiment, the inner walls 81, 91 and the outer walls 82, 92 extend in the direction of the longitudinal axis, that is in the vertical direction in the direction of the drawing. Each of the inner walls 81, 91 and outer walls 82, 92 can include an angle between 20 and 160 with the first or second side walls 3, 4 of the first wall element 2. The first opening 12 is arranged between the inner walls 81, 91 of the second and third wall elements 8, 9. A second opening 13 and an optional third opening 14 are arranged outside one of the outer walls 82, 92 of the second or third wall elements 8, 9. The second opening 13 and the third opening 14 are provided in the deflection surface at the side which faces the second side wall 4 of the first wall element 2. The inner wall of each wall element can in particular be parallel to its outer wall. Furthermore, the second and third wall elements can have inner walls 81, 91 and outer walls 82, 92 respectively in parallel with one another.

(19) The first wall element 102 of the second installation body 101 adjoins the second and third wall elements 8, 9. The second installation body 101 has a first wall element 102 which extends in the direction of the longitudinal axis 10 of the mixing element and has a first side wall 103 and a second side wall 104 which is arranged opposite the first side wall 103. The first side wall 103 and the second side wall 104 are arranged substantially parallel to the longitudinal axis 10.

(20) A deflection element 111 is arranged adjacent to the first wall element 102. The deflection element 111 has a deflection surface extending in the transverse direction to the wall element 102 at both sides thereof. A first opening 112 is provided in the deflection surface at the side which faces the second side wall 104 of the wall element 102. A second and a third wall element 108, 109 are opposite the first wall element 102 in the direction of the longitudinal axis 10 adjacent to the first opening 112. That is, the second and third wall elements 108, 109 are located downstream of the first wall element 102. The second and third wall elements 108, 109 bound a passage starting from the first opening 112 and extending in the direction of the longitudinal axis 10. A second opening 113, 114 is provided in the deflection surface at the side which faces the first side wall 103 of the wall element 102. The second or third wall elements 108, 109 adjoin the second opening 113, 114.

(21) A second wall element 108 and a third wall element 109 are arranged adjacent to the first opening 112. The second and third wall elements 108, 109 extend in the direction of the longitudinal axis 10 of the mixing element. The second wall element has an inner wall 181 and an outer wall 182 and the third wall element has an inner wall 191 and an outer wall 192. The outer walls 182, 192 and the inner walls 181, 191 extend substantially in the direction of the longitudinal axis 10 of the mixing element. They are respectively parallel to one another in the present embodiment. Each of the inner walls 181, 191 and outer walls 182, 192 include an angle between 20 and 160 with the first or second side walls 103, 104 of the first wall element 102, 90 in the present case. The first opening 112 is arranged between the inner walls 181, 191 of the second and third wall elements 108, 109 and at least one second opening 113, 114 is arranged outside one of the outer walls 182, 192 of the second or third wall elements 108, 109. The second opening 113 and/or a third opening 114 are provided in the deflection surface at the side which faces the second side wall 104 of the first wall element 102.

(22) The second installation body 101 containing the first wall element 102, the deflection element 111 and the second and third wall elements 108, 109 is arranged rotated about the longitudinal axis 10 by an angle of 10 up to and including 180, in the specific example of 180, with respect to the first installation body 1.

(23) The first installation body 1 and the second installation body 101 have the same structure, that is they contain the same wall elements and the same deflection elements which are arranged at respectively the same angles and spacings from one another.

(24) The first installation body 1 and the second installation body 101 are connected to one another via a plurality of common bar elements 15, 16, 17, 18.

(25) FIG. 2a shows an embodiment of a detail of a mixing element in accordance with a second embodiment of the invention. The structure of the mixing element does not substantially differ from the mixing element in accordance with FIG. 1; the same reference numerals as in FIG. 1 are therefore used for the same parts. Only the differences from the embodiment in accordance with FIG. 1 should be looked at in the following. A first installation body 1 and a second installation body 101 are shown in turn of the mixing element. The installation bodies are intended for installation into a mixer housing which has a circular or elliptical cross-section. The cross-sectional extent of the inner wall of the mixer housing, not shown, is indicated by a chain-dotted line. The diameter of the mixer housing is shown by a reference line 36. FIG. 2a furthermore shows a separation element 27 which is formed as an arm as well as two separation elements 28 which are formed as strips extending at the inner wall of the bar element 15, 17, 18. In accordance with a variant, the strips can naturally also be attached to the bar element 16 or also only to one of the bar elements.

(26) FIG. 2b shows an embodiment of a detail of a mixing element in accordance with the second embodiment of the invention with a separation element 29 in accordance with a second variant. This separation element is formed as a connection surface between the bar element 18 and the wall element 102.

(27) FIG. 2c shows an embodiment of a detail of a mixing element in accordance with a second embodiment of the invention with a separation element 30 in accordance with a third variant. This separation element 30, unlike the strip, forms a deflection surface which is substantially wider than the wall thickness of the separation element. In addition, a cut-out is provided in the bar element to which the separation element 30 is attached.

(28) FIG. 2d shows an embodiment of a detail of a mixing element in accordance with a second embodiment of the invention with a separation element 31 in accordance with a fourth variant. This separation element 31 forms a strip which connects the bar element to the wall element 102. The separation element 31 differs from the separation element 29 in that no specific connection surface is formed. The width of the surface of the separation element facing the filler material does not substantially differ from the wall thickness of the separation element. In the assembled state, the outer surface of the separation element extends along the inner wall of the mixer housing. This separation element can in particular also contribute to the increase in the stability of the installation body since it acts in a similar manner to a brace.

(29) FIG. 3 shows a view of a first embodiment of a mixing element in accordance with the invention. The mixing element contains installation bodies, as shown in FIG. 2. Furthermore, the mixing element contains an inlet element which contains the feed passages for the components to be mixed. The mixing ratio of the two components can be equal to 1:1, but can also be different, that is not equal to 1:1. 11 installation bodies are shown in FIG. 3. All installation bodies are connected to one another by bar elements 15, 16, 17, 18.

(30) FIG. 4 shows a section through the installation body 1 in accordance with FIG. 2. The first wall element 2 and the bar elements 15, 16, 17, 18 are cut. The deflection element 11 is visible in the section in accordance with FIG. 4. The deflection element 11 contains the first opening 12 which is arranged at the left side of the first wall element 2 in FIG. 4, that is on the side of its first side wall 3. The second opening 13 and the third opening 14 are arranged on the opposite side, that is on the second side wall 4. The first opening 12 is arranged offset with respect to the second and third openings 13, 14. A part element 26 of the deflection element is arranged between the second and third openings. The fluid which impacts onto the part element 26 is deflected in the direction of the second opening 13 and of the third opening 14. At the peripheral side, the second opening 13 and the third opening 14 are bounded by the mixer housing 210.

(31) FIG. 5 shows a section through the second and third wall elements 8, 9 of the installation body 1. The direction of gaze is in the flow direction so that the first wall element 102 of the installation body 101 is visible. The deflection element 111 adjoins the first wall element 102 of the installation body 101. The deflection element 111 contains a first opening 112 which is arranged on the side of the second side wall 104. A second opening 113 and a third opening 114 are arranged on the side of the first side wall 103. The second opening 113 and the third opening 114 are arranged offset to the first opening 112. The first, second and third openings 112, 113, 114 are arranged such that a part element is respectively arranged opposite each of the openings, that is a first part element opposite the first opening 112, a second part element 127 opposite the second opening 113 and a third part element 128 opposite the third opening.

(32) FIG. 6 shows a section through an inlet part of a static mixer and a mixing element in accordance with FIG. 3. The static mixer includes a mixer housing 210 in which the mixing element and the inlet element are received. The mixer housing is received in a connection element 220 which serves for connection to a cartridge.

(33) The bar elements 15, 16, 17, 18 hold all installation bodies of the mixing element connected to one another. Each of the bar elements increases the bending stiffness of the static mixer. It can furthermore be prevented by the bar elements that a break of the mixing element occurs in the operation of the mixer, in particular when at least two mixing elements are arranged on opposite sides of the first wall elements. Furthermore, it is ensured via the bar element during the manufacture of the installation body in the injection molding process that the polymer melt can flow from the first installation body 1 to the first and all further installation bodies 101 arranged downstream. Without the bar elements, the transition from the wall element 8 or 9 to the wall element 102 disposed downstream would namely only be composed of the common sectional surface and any reinforcement thereof. That is the sectional surface in this case is composed of two squares which would have a side length corresponding to the wall thickness 7. The total polymer melt for the installation bodies disposed downstream would have to pass through these restriction points, which would result in local pressure peaks in the tool. In addition, a long dwell time of the polymer melt would result in the regions of the wall elements which would come to lie close to the tubular housing in use, which would result in variations in the polymer melt and under certain circumstances in a deterioration of the physical properties and in inhomogeneity so that such a mixing element can only be manufactured in the prior art by the use of a melt containing a foaming agent for generating a foamed structure.

(34) For this reason, in accordance with the invention, the bar elements for forwarding the polymer melt in the manufacturing process are provided from one installation body to each of the adjacent installation bodies.

(35) The static mixer is usually produced from plastic by means of which even comparatively complicated geometries can be realized in the injection molding process. The totality of installation bodies 1, 101 has a length dimension 24 and each of the cross-sectional areas 23, 123 have a wall thickness 7 in particular for static mixers including a plurality of installation bodies. The ratio of length dimension 24 to wall thickness 7 amounts to at least 40, preferably at least 50, particularly preferably at least 75. For the preferred use of static mixers for small quantities of filler material, the wall thickness 7 is less than 3 mm, preferably less than 2 mm, particularly preferably less than 1.5 mm. The totality of the installation bodies 1, 101 has a length dimension 24 between 5 and 500 mm, preferably between 5 and 300 mm, preferentially between 50 and 100 mm.

(36) The pressure loss and the required mixer length of mixers in accordance with the invention and of the embodiments in accordance with the invention with a separation element will be compared in the following.

(37) A helical mixer (I), a mixer in accordance with EP 1 426 099 (Type MBT 6.5-12-D), a mixer in accordance with EP 2 181 827 (Type MBT 6.5-12-DV3), a mixer in accordance with a first embodiment with a ring-shaped separation element (Type MBT 6.5-12-D Ring, FIG. 2d), furthermore a mixer in accordance with the embodiment in accordance with FIG. 2a, a mixer in accordance with the embodiment in accordance with FIG. 2b, a mixer in accordance with the embodiment in accordance with FIG. 2c.

(38) All simulations were carried out using a filler material having the same physical properties.

(39) TABLE-US-00001 Pressure Volume Type CoV [bar] [cm.sup.3] MB6.5-11-D (I) 0.035 2.80 2.27 MBT6.5-12-D 0.030 3.56 1.73 (II) MBT6.5-12-DV3 0.022 3.28 1.65 (III) MBT6.5-12-D 0.013 3.15 1.63 Ring (FIG. 2d) (IV) FIG. 2a (V) 0.020 3.25 1.65 FIG. 2b (VI) 0.017 3.30 1.63 FIG. 2c (VII) 0.018 3.20 1.63

(40) Column 2 of the table shows the mixing quality (CoV) for the individual mixer types in accordance with column 1.

(41) The mixing quality in a plane A is described by means of the coefficient of variation CoV. It is defined as the standard deviation of the concentration distribution in A standardized with the mean value of the concentration c in A.

(42) $\mathrm{CoV}=\frac{\sqrt{\frac{1}{A}{}_A{\left(c-\stackrel{\_}{c}\right)}^2\mathrm{dS}}}{\stackrel{\_}{c}}$$\stackrel{\_}{c}=\frac{1}{A}{}_A\mathrm{cdA}$

(43) With a better mixing, the CoV becomes smaller. For the comparison of different mixers, the reduction in the coefficient of variation CoV was determined over a predefined mixer length with the same distribution and thus also the same CoV before the mixers; the mixer which has a smaller CoV in accordance with the predefined length therefore mixes more intensely or better.

(44) The pressure set down in the table is the pressure which has to be applied to convey the corresponding filler material through the mixer. The volume corresponds to the volume of the filler material which remains in each of the mixers I, II, III, IV, V, VI, VII, that is the loss portion of the filler material. It is a general objective, above all for expensive filler materials, to minimize this loss portion as much as possible.

(45) Not only clear differences between mixers of different geometrical construction, such as the helical mixer I and the mixer II, are revealed, but also clear differences between the mixers of substantially the same construction II-VII. The difference in mixing quality between mixer II and mixer III is due to the surprising effect described in EP 2 181 827 A1 in accordance with which the provision of bars which connect a plurality of mixing elements to one another surprisingly effects a reduction in the pressure even though the volume of the mixer III available for the filler material is less than that of mixer II. When the volume available for the filler material in the mixer decreases, the expectation is that the pressure required for conveying the filler material increases since a smaller volume gives rise to the expectation of a smaller free cross-sectional area and thus a greater constriction effect. The change in the volume available for the filler material is at around 5% in this example. At the same time, this means that the loss portion, which corresponds to the volume in the inner mixer space which is taken up by the filler material, reduces by around 5%.

(46) It furthermore resulted from the simulations that further improvements in the mixing quality of the mixer III are surprisingly possible. Each of the mixers IV, V, VI, VII has a higher mixing quality than mixer III. This effect is due to the separation elements such as are shown in the embodiments in accordance with FIG. 2a, FIG. 2b, FIG. 2c and FIG. 2d. Surprisingly, both an improvement in the mixing quality is achieved and the pressure is reduced. The volume can be reduced, that is the loss portion can be reduced, due to the improvement in the mixing quality. This means that the mixer in accordance with one of the variants in accordance with the invention can be operated at a lower pressure than the prior art and that the mixer has an equal or even smaller mixer length.

(47) On a comparison of all mixer types based on the mixing quality of the helical mixer 0.035, the percentage improvements of mixers IV, V, VI, VII shown in the following table result in comparison with mixer III.

(48) TABLE-US-00002 Mixer Pressure [%] Vol. [%] (I) 135.81% 218.87% (II) 148.00% 143.18% (III) 100.00% 100.00% (IV) 56.75% 58.50% (V) 90.08% 90.73% (VI) 77.74% 76.11% (VII) 79.82% 81.00%

(49) Mixers I and II from the prior art accordingly deliver substantially poorer values for the pressure and for the volume required for the mixing.

(50) On a comparison of all mixer types based on the mixing quality of the helical mixer 2.80, the percentage improvements of mixers IV, V, VI, VII shown in the following table result in comparison with mixer III.

(51) TABLE-US-00003 Mixer Pressure [%] Vol. [%] (I) 135.81% 117.44% (II) 148.00% 113.96% (III) 100.00% 100.00% (IV) 56.75% 95.08% (V) 90.08% 98.89% (VI) 77.74% 99.10% (VII) 79.82% 96.59%

(52) Mixers I and II from the prior art accordingly deliver substantially poorer values for the pressure and for the volume required for the mixing. Mixer IV must in particular be emphasized in this connection whose pressure is almost 50% lower than that of mixer III which does not differ greatly in construction.

(53) Comparison with mixers I and II accordingly deliver even greater improvements. Both an improvement in the mixing quality and a reduction in the pressure which is required to urge the filler material through the mixer and to dispense it can thus surprisingly be achieved by the provision of separation elements.

(54) It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.