EP2614883A1 - Static mixer - Google Patents

Abstract

The mixing element (100) has an aperture (12) between inner walls (81, 91) of wall elements (8, 9). Other apertures (13, 14) are provided in a deflection surface at a side, which is turned towards a side wall (4) of a third wall element (2). A mounting body (1) is connected with another mounting body (101) over common bar elements (15-18). Separating elements e.g. strips, are connected with the bar elements and extended from an inner wall of a mixer housing transverse to a longitudinal axis (10) into mixture chambers (20, 120).

Description

The invention relates to a static mixer made of plastic comprising a mounting body for installation in a tubular mixer housing. This installation body has a longitudinal axis, which is aligned in the direction of a fluid flowing into the installation body, so that a mixing space can be clamped by the installation body. The mixing chamber has, in a plane normal to the longitudinal axis, a flow cross-sectional area which substantially corresponds to the flow cross-sectional area of the tubular mixer housing. The installation body comprises a wall element for dividing and / or deflecting the fluid flow in a direction deviating from the longitudinal axis.

Such a static mixer is for example from the EP1426099 B1 known. In this static mixer, two components are mixed together in a three-part mixing process in which the mass is first divided, then expanded and displaced by means of a plurality of similar mixing elements. Depending on the physical properties of the components, this mixing process must be done several times. For this reason, the static mixer includes a plurality of structural bodies of the same type, which are arranged one behind the other. These mixers are used in particular for mixing small amounts of the components, that is, a few milliliters to about 1000 milliliters. As a result, these mixers have a mixing space with a diameter of less than 16 mm and a length of over 50 mm. This has the consequence that the wall thicknesses of the wall elements of this mixer can be less than 1 mm, often even less than 0.5 mm.

Such a static mixer according to EP1426099 B1 made of plastic is preferably produced by injection molding. The production of a mixer of 30 mm length with a wall thickness of less than 3 mm by means of the injection molding process as in Fig. 1 This patent has been shown so far not possible because the flow path from the injection point of the injection mold to the opposite end of the mixer would require too high internal cavity pressures. In order to produce a static mixer with such small wall thicknesses economically by injection molding, each mounting body is connected to the adjacent mounting body via web elements. These web elements make it possible for the polymer melt in the injection molding tool to pass from an installation body to an adjacent installation body and to keep the mold internal pressures below 1000 bar, so that failure of the injection mold can be prevented, as in an arrangement of two installation bodies Fig. 4 of the EP 2 181 827 A1 is shown, which in their arrangement of wall elements and deflecting the embodiment of FIG. 15 or 17 of EP1426099 B1 equivalent. As an essential difference to the EP1426099 B1 serve the web elements of the EP 2 181 827 A1 only the connection of an installation body to an adjacent installation body. On the other hand, the web elements according to FIG EP1426099 B1 extend over several mounting body. The web elements claim mixing space and were therefore avoided as far as possible according to the previous teaching, or designed such that they connect only a part of the mounting body of the mixer together, as shown in FIG EP1426099 B1 a maximum of 5 mounting bodies. By the method according to EP 2 181 827 A1 It was only possible to provide web elements, which connect only two adjacent mounting body with each other. However, this development has proved disadvantageous in that the stability of the mixing element constructed from the installation bodies is affected. In particular, during the discharge of viscous masses, it has been shown that the mixing element can break. However, it has according to when using a mounting body EP 2 181 827 A1 shown that the flow rate of the filling material is subject to great variations.

The object of the invention is to provide a mixing element in which the variations in the flow rate of the filling material are reduced by an installation body.

The object of the invention is achieved by a mixing element, wherein at least a first and second mounting body via a common

Bar element are connected to each other, on which in addition to a deflecting a release element is provided. The release element is designed as a projection which extends from an inner wall of the mixer housing transversely to its longitudinal axis into a mixing space. By providing a stake element, the mixing element is also stiffer, that is, increased resistance to breakage.

In an experiment with a filling material A, which is sold under the trade name Voco registrado X-tra and a filling material B, which is sold under the trade name Kettenbach Monopren, it has been found that the homogeneity of the mixture for a mixing element according to the invention in the same Mixer length is improved over the prior art. In particular, the mixer may have a greater length due to the lower pressure loss. The maximum force that can be manually applied to push the fill mass through the mixing element is limited. It follows that a mixing element, which has a reduced pressure loss, is easier to handle with the same length. Furthermore, the mixing element according to the invention can be extended with respect to a mixing element of the prior art with installation bodies which have a greater pressure loss. That is, the mixing element may contain more body than, for example, that of the EP 2 181 827 A1 previously known mixing element, whereby the quality of mixing can be improved.

The mixing element is provided for a static mixer for installation in a tubular mixer housing. The mixing element has a longitudinal axis along which a plurality of mounting bodies are arranged one behind the other, wherein a first mounting body has a first wall element which extends in the direction of the longitudinal axis. The wall element has a first side wall and a second side wall, which are arranged opposite the first side wall is. A deflection element is arranged adjacent to the first wall element and has a transverse to the wall element on both sides of the Wall element extending deflection surface, wherein a first opening in the deflection surface on the side facing the first side wall of the wall element, is provided.

Adjacent to the first opening a second and a third wall element are arranged, wherein the second and third wall elements extend in the direction of the longitudinal axis and each having an inner wall and an outer wall, which extend substantially in the direction of the longitudinal axis. Each of the inner walls and outer walls subtend an angle between 20 ° and 160 ° to the first or second side wall of the first wall element. The first opening is arranged between the inner walls of the second and third wall elements and a second opening is arranged outside one of the outer walls of the second or third wall element, wherein the second opening in the deflection surface on the side facing the second side wall of the first wall element, is provided.

Adjacent to the first opening, a second and a third wall element are thus arranged in the direction of the longitudinal axis opposite to the first wall element, the second and third wall element delimiting a channel extending from the first opening and extending in the direction of the longitudinal axis. A second opening is provided in the deflection surface on the side facing the second side wall of the wall element, the second or third wall element being connected to the second opening. Furthermore, the first wall element of the second installation body adjoins the second and third wall elements. At least the first mounting body is connected to the second mounting body via a common web element with each other, advantageously, at least five adjacent mounting body via a common web element are interconnected. To compensate for differences in the flow rate of the filling compound, a release element is provided, which is connected to the web element. The release element is designed as a projection which extends from the inner wall of the mixer housing transversely to the longitudinal axis of the mixer into the mixing chamber. The term transverse should be understood to mean an angle of at least 45 ° up to and including 90 °.

The release element is designed in particular as a bar or rib. A strip or a rib is to be understood as an element which has a windward surface which faces the flow, that is to say the filling compound moves toward this windward surface in the operating state of the mixer. The leeward surface substantially opposite a leeward surface is disposed, which is averted from the flow, that is, the filling material moves in the operating state of the mixer away from the leeward surface. The least possible distance of a point on the windward surface and leeward surface corresponds to the thickness or wall thickness of the release element. The wall thickness is usually smaller than the length and / or width of at least one of the windward or leeward surfaces. The windward surface and the leeward surface thus span a wall having the appropriate thickness or wall thickness. Of course, it is possible that the wall thickness is not the same at any point either the windward surface or the leeward surface. At least part of the wall of the release element is disposed adjacent to the inner wall of the tubular mixer housing. The windward and / or leeward surface may in particular run transversely to the longitudinal axis of the mixer, that is, at least partially have an angle of more than 45 ° to the longitudinal axis of the mixer. In particular, the release element can be arranged substantially perpendicular to the longitudinal axis of the mixer, that is, particularly preferably enclose an angle of 90 ° with the longitudinal axis of the mixer. The release element is preferably arranged adjacent to the mixer housing, so that the wall flow is deflected via the release element. This wall flow has a lower flow velocity than the flow in the mixing space formed by the installation body, which is free of wall effects. Thus, an improved deflection of this wall flow and thus an improved mixing effect can be achieved by the detachment elements, so that the required overall length of the mixer can consequently be reduced. Particularly advantageous results have been found for release elements which have between 20% and 50% reduction have the available for the fluid flow free cross-sectional area in the mixer. If the constriction at the point of the release element is less than 20%, no measurable improvement in the mixing effect is achieved; if the constriction, ie the reduction of the cross-sectional area exceeds 50%, this leads to an excessive increase in the pressure loss. This reduction by 20% and 50% of the free cross-sectional area corresponds to a reduction of 5 to 12.5% of the cross-sectional area of the mixer housing, preferably 5 to 10% of the cross-sectional area of the mixer housing.

The release element preferably has a wall thickness that substantially coincides with the wall thickness of the wall elements or deflection elements. The wall thickness may differ by a maximum of 10%, preferably a maximum of 5% of the average wall thickness of the wall elements or deflecting elements. This range of wall thickness is particularly advantageous for processing the mixer by injection molding.

Furthermore, it is advantageous if the release elements are not arranged periodically recurring in the mixer. That is, at least part of the mounting body contains no release elements. This results in a local disturbance of the flow, which is advantageous for the mixing effect, but which is finally compensated in the area of the mixer between two adjacent separation elements.

In particular, the release element may be formed as a bar or rib, which extends at least partially on an inner wall of the bar member or as a bar which extends from the web element to a deflecting element. The strip has a windward side which can be flowed by a filling compound and has a leeward side from which the mixed filling material flows away. The windward or leeward side may have a surface which is arranged normal to the longitudinal axis of the mounting body. It may also have a tilt with respect to the longitudinal axis. In particular, the strip can include an angle of 0 to 80 ° to the longitudinal axis, preferably from 0 to 75 °, particularly preferably from 0 to 60 °. As the angle of inclination that the strip includes with the longitudinal axis increases, so does the pressure loss, but also the degree the deflection of the filling mass flow increases. Depending on the design of the release element, the degree of deflection can be adjusted via the angle of inclination. The release element can be designed, in particular, as an arm which projects into the mixing space delimited by web element, deflection element and wall element. In particular, the arm can be formed as an extension of one of the wall elements, web elements or deflecting elements.

According to a further embodiment, the release element may be formed as a strip, via which the web element and the deflecting element are interconnected. This embodiment has as an additional advantage that the mounting body can be additionally stiffened by this bar. In particular, a web element can be connected to a further web element via such a strip.

In particular, the second mounting body can also have a first wall element, which extends in the direction of the longitudinal axis and have a first side wall and a second side wall, which is arranged opposite the first side wall. A deflection element may be arranged adjacent to the first wall element and the deflection element have a deflection surface extending transversely to the wall element on both sides of the wall element, a first opening in the deflection surface being provided on the side facing the first side wall of the wall element.

Adjacent to the first opening can again be arranged a second and a third wall element, the second and third wall elements extending in the direction of the longitudinal axis and each having an inner wall and an outer wall, which extend substantially in the direction of the longitudinal axis. Each of the inner walls and outer walls may enclose an angle between 20 ° and 160 ° to the first or second side wall of the first wall element. The first opening may be arranged between the inner walls of the second and third wall elements and a second opening may be located outside one of the outer walls of the second or third wall member, wherein the second opening may be provided in the deflecting surface on the side facing the second side wall of the first wall member.

This means that adjacent to the first opening a second and a third wall element can be arranged in the direction of the longitudinal axis opposite to the first wall element, wherein the second and third wall element can define a channel extending from the first opening and extending in the direction of the longitudinal axis. A second opening can be provided in the deflection surface on the side facing the second side wall of the wall element, wherein the second or the third wall element can connect to the second opening, wherein the first wall element, the deflection element and the second and third wall element existing second mounting body can be arranged rotated about the longitudinal axis by an angle of 10 ° up to and including 180 ° with respect to the first mounting body.

In particular, the second mounting body may have the same structure as the first mounting body. The first mounting body may be arranged rotated about the longitudinal axis by an angle of 180 ° with respect to the second mounting body.

In particular, all mounting bodies of the mixing element can be connected by means of a bar element. The web element can be arranged on the outer circumference of the deflecting element. On each side of the wall element may be provided a web element, but also a plurality of web elements may be provided, in particular, two web elements may be provided on each side of the wall element.

The wall element can enclose an angle of 90 to 130 ° with the deflection surface.

The deflection surface may have an at least partially curved in the direction of the flowing fluid surface for deflecting the fluid flow in a direction deviating from the longitudinal axis, in particular For example, a progressive curvature can be provided in the flow direction and in the direction of the mixer housing.

According to an alternative embodiment, the deflection surface may be substantially planar. The deflection surface may in particular extend substantially at an angle of 90 ° to the wall element.

The deflection surface of the first mounting body is in particular designed such that it covers the openings of the second mounting body in the direction of the longitudinal axis.

According to a further embodiment, the surface of the deflecting element on the side facing the first side wall of the wall element, at least partially lie in a transverse plane, which is aligned at an angle of 60 ° to 90 ° to the longitudinal axis. Furthermore, the surface of the deflecting element on the side, which is the second side wall of the wall element facing, lie in a transverse plane, which is aligned at an angle of 60 ° to 90 ° to the longitudinal axis.

Between the second and third wall element of the first installation body and the first wall element of the second installation body, a reinforcing element may be provided at its connection point. By this reinforcing element, the transition between the first and second mounting body in its dimensional stability and rigidity can be improved. Also, the flow cross section for the polymer melt is increased at a junction with reinforcing element. The reinforcing element may be formed, for example, as a thickening or a rib.

The static mixing element may in particular contain a foamed polymer. Compared to the conventional injection molding process, a propellant-containing polymer is used in this case for the production of the static mixer, which foams during or immediately after the injection. In particular, the injection molding method comprises the step of injecting a blowing agent-containing polymer into a Injection mold at a cavity pressure of less than 600 bar, more preferably less than 500 bar.

According to one embodiment, a recess may be provided in the web element adjacent to the release element. Through the recess, a material savings is possible, as well as a simplification of the production of the release element. For example, during the manufacture of the installation body by injection molding a movable tool element can be used to produce the release element. This movable tool element is inserted through the recess in the mixing chamber and the release element produced by pulling the tool element from the mixer chamber.

A plurality of detachment elements may be provided in parallel arrangement with each other. The release elements are located next to each other with respect to the longitudinal axis. For example, a strip may be attached to two or more of the four web elements, or an arm may protrude into the mixer chamber formed by the mounting body.

The detachable element designed in particular as a strip or the arm can have a length of at least 1/10 to half the diameter of the mixer housing enveloping the installation body. The wall thickness of the detachment element essentially corresponds to the wall thickness of one of the wall elements or deflecting elements.

In a projection onto a normal plane to the longitudinal axis, the surface of the detachment element exposed to the flow, that is to say the windward side thereof, is at most half the cross-sectional area of the installation body available for the filling compound, preferably at most one third of the cross-sectional area available for the filling compound Mounting body.

Furthermore, a detachment element can be provided in at least one part of the installation body. It is also possible that only a single mounting body has a release element.

Furthermore, detaching elements according to one of the following embodiments may be provided in any combination.

A static mixer includes a mixing element according to one of the preceding embodiments and a mixer housing surrounding the mixing element.

The mounting body has a length dimension and a diameter. For non-circular tubular mixer housings, the diameter corresponds to the edge length when the cross-sectional area of the tubular mixer housing is square. For other forms of mixer housings having, for example, rectangular or oval cross-sections, an equivalent diameter D _{a is} determined assuming that the cross-sectional area is circular, that is, using the formula D _a = 2 * (A / π) ^1/2 . D _a then stands for the equivalent diameter, A for the actual cross-sectional area. The ratio of length dimension to diameter is at least 1, using as diameter either the diameter of the circular cross section or the equivalent diameter for non-circular cross sections.

The length dimension is the extent of the mounting body in the direction of the longitudinal axis. The ratio of length dimension to diameter may in particular be greater than 1.

In particular, a plurality of installation bodies can be arranged one behind the other along the longitudinal axis. These mounting bodies can either have the same construction or mounting body of different construction can be combined, so that a mixer arrangement, as for example in the EP1312409 B1 is shown, arises. The adjacent installation bodies are connected to each other at least via the web elements, so that the mixing element, which is constructed from this plurality of installation bodies, is formed as a monolithic part. That is, the mixing element is produced in its entirety in a single injection mold.

The installation body or the entirety of the installation body may have a length dimension between 5 and 500 mm, preferably between 5 and 300 mm, preferably between 50 and 100 mm.

The static mixer includes a mixing element according to one of the preceding embodiments and a mixer housing surrounding the mixing element. The mixing element has a longitudinal axis, which coincides in the assembled state with the longitudinal axis of the mixer housing. Therefore, each of the mounting body has this longitudinal axis. The longitudinal axis is aligned in the direction of a fluid flowing into the static mixer. The fluid comprises at least two components which are supplied via an inlet element arranged upstream of the mixing element.

By means of the diverting element, the flow of the fluid to be mixed is deflected inside the mixing space, so that the components which enter as strands in the tubular mixing element with built-mixing element are continuously subdivided into strips of decreasing width during their passage through the static mixer Even difficultly mixable or highly viscous components can be processed with this static mixer.

The fluid to be mixed usually comprises two different components. In most cases, the components are in the liquid state or as viscous masses. These include, for example, pastes, adhesives, but also fluids which find use in the medical field, which contain active pharmaceutical ingredients, or fluids for cosmetic applications, as well as foods. In particular, such static mixers also find use as disposable mixers for mixing a thermosetting mix of flowable components, such as the mixture of multicomponent adhesives. Another preferred use is in the mixture of impression compounds in the dental field.

The static mixers described above are suitable as disposable mixers, since their manufacturing and material costs are low as soon as the corresponding injection mold is made. Furthermore, the static mixers are used in dosing and / or mixing devices. The static mixer can be attached to a dispensing device or a dispensing cartridge, in particular a multi-component cartridge. By way of example, a multicomponent cartridge may be mentioned by way of example, which comprises a discharge device and a pipe coupled to the discharge device, which contains a static mixer according to one of the preceding exemplary embodiments.

Fig. 1

ein Ausführungsbeispiel eines Ausschnitts eines Mischelements nach einem ersten Ausführungsbeispiel der Erfindung,

Fig. 2a

ein Ausführungsbeispiel eines Ausschnitts eines Mischelements nach einem zweiten Ausführungsbeispiel der Erfindung mit einem Ablöseelement nach einer ersten Variante,

Fig. 2b

ein Ausführungsbeispiel eines Ausschnitts eines Mischelements nach einem zweiten Ausführungsbeispiel der Erfindung mit einem Ablöseelement nach einer zweiten Variante,

Fig. 2c

ein Ausführungsbeispiel eines Ausschnitts eines Mischelements nach einem zweiten Ausführungsbeispiel der Erfindung mit einem Ablöseelement nach einer dritten Variante,

Fig. 3d

ein Ausführungsbeispiel eines Ausschnitts eines Mischelements nach einem zweiten Ausführungsbeispiel der Erfindung mit einem Ablöseelement nach einer vierten Variante,

Fig. 3

eine Ansicht eines Mischelements mit Einbaukörpern gemäss Fig. 2,

Fig. 4

einen Schnitt durch einen Einbaukörper gemäss Fig. 2,

Fig. 5

einen Schnitt durch einen Einbaukörper, der benachbart zum Einbaukörper gemäss Fig. 4 angeordnet ist,

Fig. 6

einen Schnitt durch ein Einlassteil eines statischen Mischers und Mischelement gemäss Fig.3.

The invention will be explained with reference to the drawings. Show it:

Fig. 1

An embodiment of a section of a mixing element according to a first embodiment of the invention,

Fig. 2a

An embodiment of a section of a mixing element according to a second embodiment of the invention with a release element according to a first variant,

Fig. 2b

An embodiment of a section of a mixing element according to a second embodiment of the invention with a release element according to a second variant,

Fig. 2c

An embodiment of a section of a mixing element according to a second embodiment of the invention with a release element according to a third variant,

Fig. 3d

An embodiment of a section of a mixing element according to a second embodiment of the invention with a release element according to a fourth variant,

Fig. 3

a view of a mixing element with mounting bodies according to Fig. 2 .

Fig. 4

a section through an installation body according to Fig. 2 .

Fig. 5

a section through an installation body, the adjacent to the installation body according to Fig. 4 is arranged

Fig. 6

a section through an inlet part of a static mixer and mixing element according to Figure 3 ,

In Fig. 1 an embodiment of a mixing element 100 for a static mixer according to a first embodiment of the invention is shown. The mixing element comprises 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 chamber 20, which is located in the interior of the tubular housing. Through the mixing chamber 20, a fluid to be mixed flows, which usually consists of at least two different components. In most cases, the components are in the liquid state or as viscous masses. These include, for example, pastes, adhesives, but also fluids which find use in the medical field, which contain active pharmaceutical ingredients, or fluids for cosmetic applications, as well as foods. In particular, such static mixers also find use as disposable mixers for mixing a thermosetting mix of flowable components, such as the mixture of multicomponent adhesives. Another preferred use is in the mixture of impression compounds in the dental field.

The mixing element according to Fig. 1 thus comprises an installation body 1 for installation in a tubular mixer housing, wherein the mounting body 1, 101 has a longitudinal axis 10 which is aligned in the direction of a fluid flowing to the installation body 1. Through the mounting body 1, a mixing chamber 20 can be clamped, which is peripherally bounded by a mixer housing, not shown. In the Fig. 1 is to facilitate the idea a cube-shaped mixing space indicated. The side surfaces of the cube may represent the inner walls of the mixer housing. The fluid flows from the top surface of the cube, which has a Flow cross-sectional area 22 forms, in the direction of the mounting body 101.

The mounting body 1 and the mounting body 101 have the same structure, however, the mounting body 101 is rotated by 180 ° about the longitudinal axis 10. Like the mixing space 20, the mixing space 120 has a flow cross-sectional area 122 in a plane 121 arranged normal to the longitudinal axis 10, which essentially corresponds to the flow cross-sectional area of the tubular mixer housing surrounding the installation body 101. For mounting bodies 1, 101 which have at least one plane of symmetry which divides the mixing space into two equal parts, the longitudinal axis lies in this plane of symmetry. The mixing chamber is limited by the mixer housing, not shown. In this embodiment, the mixing element is to be installed in a mixer housing with a rectangular or square cross-section. The internal dimension of the mixer housing used to determine the equivalent diameter is indicated at reference 36.

The mounting body 1 contains at least a first wall element 2, which serves to divide the fluid flow in two substreams flowing essentially parallel to the longitudinal axis 10. The wall element 2 has a first side wall 3 and a second side wall 4. The section of the first wall element 2 with the plane 21 results in a cross-sectional area 23. This cross-sectional area 23 is at most 1/5, preferably at most 1/10, particularly preferably at most 1/20, of the flow cross-sectional area 22 of the mixing chamber 20 without installation body. The fluid thus flows on 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 broad side 5, a second broad side 6 and a first and a second longitudinal side 25, 35. The first broad side 5, the second broad side 6, the first longitudinal side 25 and the second longitudinal side 35 form the circumference of each of the side walls 3, 4. The longitudinal sides 25, 35 extend substantially in Direction of the longitudinal axis 10 and the first broad side 5 and second broad 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 rod element which divides the fluid flow into two parts, the deflection of which, with the exception of the deflection at the edges of the first broad side 5, being negligible. The wall thickness 7 of the wall element 2 is usually less than 1 mm for a mixing element with a total length of up to 100 mm.

To the first wall element 2 includes a deflecting element 11, which serves to deflect the partial flows in a direction deviating from the longitudinal axis. The deflecting element has a deflecting surface extending transversely to the wall element 2 on both sides of the wall element. A first opening 12 is provided in the deflection surface on the side facing the first side wall 3 of the wall element 2.

The crossing angle between the first wall element 2 and the second or third wall element 8, 9 is in accordance with the exemplary embodiment Fig. 1 90 °. According to Fig. 1 the first wall element 2 is connected to the second wall element 8 and the third wall element 9 via the deflecting element 11. The deflecting element 11 is preferably located in a plane which is aligned parallel to the plane 21 or is arranged with an inclination angle to the plane, wherein the inclination angle is not more than 60 °, preferably not more than 45 °, particularly preferably not more than 30 ° , The smaller the angle of inclination between the surface of the deflecting element 11 and the plane 21, the lower the required overall length. In other words, the surface of the deflecting element 11 lies substantially in a transverse plane, which is oriented at an angle of 45 ° to 90 °, preferably 60 ° to 90 °, more preferably 75 ° to 90 ° to the longitudinal axis 10 ,

The wall elements 8, 9 adjoining the deflection element 11 delimit a channel extending from the first opening 12 and extending in the direction of the longitudinal axis 10. By the expression "following the deflecting element" is meant that the second and the Third wall element 8, 9 are arranged in the direction of the longitudinal axis opposite to the first wall element 2, that is, in the flow direction downstream of the first wall element 2 are arranged.

A second opening is provided in the deflection surface on the side facing the second side wall 4 of the wall element 2, wherein the second or the third wall element 8, 9 adjoin the second opening. The second and third wall element 8, 9 defines the same channel, which also starts from the first opening 12.

Adjacent to the first opening 12 thus a second and a third wall element 8, 9 are arranged. 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 has the inner wall 91 and the outer wall 92. In the present embodiment, the inner walls 81, 91 and outer walls 82, 92 extend in the direction of the longitudinal axis, ie in the drawing direction in the vertical direction. Each of the inner walls 81, 91 and outer walls 82, 92 may include an angle between 20 ° and 160 ° to the first or second side wall 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 element 8, 9. The second opening 13 and the third opening 14 are provided in the deflection surface on the side facing the second side wall 4 of the first wall member 2. In particular, the inner wall of each wall element can be parallel to its outer wall. Furthermore, the second and third wall elements may each have mutually parallel inner walls 81, 91 and outer walls 82, 92.

At the second and third wall element 8, 9, the first wall element 102 of the second mounting body 101 adjoins. The second mounting 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.

A deflecting element 111 is arranged adjacent to the first wall element 102. The deflection element 111 has a deflection surface extending transversely to the wall element 102 on both sides thereof. A first opening 112 is provided in the deflection surface on the side facing the second side wall 104 of the wall member 102. Adjacent to the first opening 112 are a second and a third wall element 108, 109 in the direction of the longitudinal axis 10 opposite to the first wall element 102. That is, the second and third wall element 108, 109 are located downstream of the first wall element 102. The second and third Wall element 108, 109 delimit a channel extending 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 on the side facing the first side wall 103 of the wall member 102. The second or the third wall element 108, 109 adjoin the second opening 113, 114.

Adjacent to the first opening 112, a second wall element 108 and a third wall element 109 are arranged. 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 each parallel to each other in the present embodiment. Each of the inner walls 181, 191 and outer walls 182, 192 enclose an angle between 20 ° and 160 ° to the first or second side wall 103, 104 of the first wall element 102, in the present case 90 °. The first opening 112 is disposed between the inner walls 181, 191 of the second and third wall elements 108, 109 and at least one second opening 113, 114 is disposed outside one of the outer walls 182, 192 of the second or third wall element 108, 109. The second opening 113 and / or a third opening 114 are provided in the deflection surface on the side facing the second side wall 104 of the first wall element 102.

The second mounting body 101 containing the first wall element 102, the deflecting element 111 and the second and third wall elements 108, 109 is at an angle of 10 ° up to and including 180, about 180 ° in the specific example of 180 °, with respect to the longitudinal axis 10 the first mounting body 1 is arranged rotated.

The first installation body 1 and the second installation body 101 according to Fig. 1 have the same structure, that is they contain the same wall elements and the same deflecting elements, which are arranged in each case at equal angles and distances from each other.

The first mounting body 1 and the second mounting body 101 are connected to each other via a plurality of common web elements 15, 16, 17, 18.

Fig. 2a shows an embodiment of a section of a mixing element according to a second embodiment of the invention. The structure of the mixing element does not differ significantly from the mixing element according to Fig. 1 Therefore, the same reference numerals are used for the same parts as in Fig. 1 , Below is also only on the differences from the embodiment according to Fig. 1 To be received. From the mixing element, in turn, a first mounting body 1 and a second mounting body 101 are shown. The mounting bodies are intended for installation in a mixer housing which has a circular or elliptical cross section. The cross-sectional profile of the inner wall of the mixer housing, not shown, is indicated by a dash-dotted line. The diameter of the mixer housing is with a reference line 36 is shown. Further shows Fig. 2a a release element 27, which is designed as an arm and two release elements 28, which are formed as extending on the inner wall of the support member 15, 17, 18 strips. Of course, according to a variant, the strips may also be attached to the web element 16 or even be attached to only one of the web elements.

Fig. 2b shows an embodiment of a section of a mixing element according to the second embodiment of the invention with a release element 29 according to a second variant, this release element is formed as a connecting surface between the web element 18 and the wall element 102.

Fig. 2c shows an embodiment of a section of a mixing element according to the second embodiment of the invention with a release element 30 according to a third variant. In contrast to the bar, this detaching element 30 forms a deflecting surface which is substantially wider than the wall thickness of the detaching element. In addition, a recess is provided in the web element to which the detachment element 30 is attached.

Fig. 3d shows an embodiment of a section of a mixing element according to a second embodiment of the invention with a release element 31 according to a fourth variant. This release element 31 forms a strip which connects the web element to the wall element 102. The release element 31 differs from the release element 29 in that no special connection surface is formed. The width of the filling compound facing surface of the release element does not differ significantly from the wall thickness of the release element. The release element extends in the assembled state with its outer surface along the inner wall of the mixer housing. This release element can contribute in particular to increase the stability of the installation body, because it acts similar to a strut.

Fig. 3 shows a view of a first embodiment of a mixing element according to the invention. The mixing element contains Mounting body, as in Fig. 2 shown. Furthermore, the mixing element contains an inlet element, which contains the supply channels for the components to be mixed. The mixing ratio of the two components can be equal to 1: 1, but also differ, that is not equal to 1: 1. In Fig. 3 11 installation bodies are shown. All mounting bodies are connected to each other by web elements 15, 16, 17, 18.

Fig. 4 shows a section through the mounting body 1 according Fig. 2 , The first wall element 2 and the web elements 15, 16, 17, 18 are cut. On average according to Fig. 4 the deflecting element 11 is visible. The deflecting element 11 includes the first opening 12, which in Fig. 4 On the opposite side, so the second side wall 4, the second opening 13 and the third opening 14 are arranged. The first opening 12 is offset with respect to the second and third openings 13, 14. Between the second and third opening, a partial element 26 of the deflecting element is arranged. The fluid which impinges on the partial element 26 is deflected in the direction of the second opening 13 and the third opening 14. On the circumference, the second opening 13 and the third opening 14 is limited by the mixer housing 210.

Fig. 5 shows a section through the second and third wall elements 8, 9 of the mounting body 1. The viewing direction is in the flow direction, so that the first wall element 102 of the mounting body 101 is visible. The deflecting element 111 adjoins the first wall element 102 of the installation body 101. The deflecting element 111 includes a first opening 112, which is arranged on the side of the second side wall 104. On the side of the first side wall 103, a second opening 113 and a third opening 114 are arranged. The second opening 113 and the third opening 114 are offset from the first opening 112. The first second and third openings 112, 113, 114 are arranged such that opposite to each of the opening is arranged in each case a sub-element, that is opposite to the first Opening 112, a first sub-element 126, opposite to the second opening 113, a second sub-element 127 and opposite to the third opening, a third sub-element 128th

Fig. 6 shows a section through an inlet part of a static mixer and a mixing element according to Figure 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 connecting element 220, which serves for connection to a cartridge.

The web elements 15, 16, 17, 18 hold all the mounting body of the mixing element connected together. Each of the web elements increases the flexural rigidity of the static mixer. Furthermore, it can be prevented by the web elements that it comes to the breakage of the mixing element during 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 during the production of the mounting body in the injection molding via the web element that the polymer melt from the first mounting body 1 to the first and all other downstream mounted bodies 101 can flow. Without the web elements, the transition from the wall element 8 or 9 to the downstream wall element 102 would consist exclusively in the common cut surface and a possible reinforcement of the same, that is, the cut surface in this case consists of two squares, one side length, the wall thickness 7 corresponds to would have. All of the polymer melt for the downstream installation bodies would have to pass through these orifices, resulting in local pressure spikes in the tool. In addition, in the areas of the wall elements that would come to rest in use near the tubular housing, a long residence time of the polymer melt would result, which would lead to changes in the polymer melt and possibly to a deterioration of the physical properties and inhomogeneity, so that in State of the art only by the use of a blowing agent-containing melt to produce a foamed structure, such a mixing element can be produced.

For this reason, according to the invention, the web elements for forwarding the polymer melt are provided in the manufacturing process of an installation body to each of the adjacent mounting body.

The static mixer is usually made of plastic, by means of which even comparatively complicated geometries can be realized in the injection molding process. In particular for static mixers comprising a plurality of installation bodies, the entirety of the installation bodies 1, 101 has a length dimension 24 and each of the cross-sectional areas 23, 123 has a wall thickness 7. The ratio of length dimension 24 to wall thickness 7 is at least 40, preferably at least 50, particularly preferred at least 75. For the preferred use of static mixers for small quantities of filling material, the wall thickness 7 is less than 3 mm, preferably less than 2 mm, more preferably less than 1.5 mm. The entirety of the mounting body 1,101 has a length dimension 24 between 5 and 500 mm, preferably between 5 and 300 mm, preferably between 50 and 100 mm.

Subsequently, the pressure loss and the required mixer length of mixers according to the prior art and the erfindungsgmässen embodiments are compared with a release element.

A spiral mixer (I), a mixer according to EP1426099 (Type MBT 6.5-12-D), a mixer according to EP 2 181 827 (Type MBT 6.5-12-DV3), a mixer according to a first embodiment with an annular release element (type MBT 6.5-12-D ring, Fig. 2d ), further a mixer according to the embodiment according to Fig. 2a , a mixer according to the embodiment according to Fig. 2b , a mixer according to the embodiment according to Fig. 2c ,

All simulations were performed with a filler having the same physical properties. Type CoV print
[bar] volume
[cm ³ ] MB6.5-11-D (I) 0035 2.80 2.27 MBT6.5-12-D (II) 0030 3:56 1.73 MBT6.5-12-DV3 (III) 0022 3.28 1.65 MBT6.5-12-D ring ( Fig. 2d ) (IV) 0013 3.15 1.63 Fig. 2a (V) 0020 3.25 1.65 Fig. 2b (VI) 0017 3.30 1.63 Fig. 2c (VII) 0018 3.20 1.63

Column 2 of the table shows the mixing quality (CoV) for the individual mixer types according to column 1.

$$\bar{c}=\frac{1}{A}\underset{A}{\int }cdA$$

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 normalized with the mean of the concentration c in A. $$\mathit{CoV}=\frac{\sqrt{\frac{1}{A}\underset{A}{\int }{\left(c-\tilde{c}\right)}^{2}dA}}{\tilde{c}}$$

$$\tilde{c}=\frac{1}{A}\underset{A}{\int }cdA$$

With better mixing, the CoV becomes smaller. For comparison of different mixers, the reduction of the coefficient of variation CoV was determined over a given mixer length with the same distribution and therefore also the same CoV before the mixers; the mixer, which has a smaller CoV after the given length, mixes more intensively or better.

The pressure given in the table is the pressure that must be used to deliver the appropriate fill mass through the mixer. The volume corresponds to the volume of the filling compound which remains in each of the mixers I, II, III, IV, V, VI, VII, that is to say the loss proportion of the filling compound. Especially for expensive fillers, it is a general objective to minimize this loss as much as possible.

It shows not only significant differences between mixers of different geometrical design, such as the spiral mixer I and the mixer II, but also significant differences between the mixers of essentially the same type II - VII. The difference in mixing quality of mixer II and mixer III is on the in EP 2 181 827 A1 described surprising effect, according to which the provision of webs which connect a plurality of mixing elements together, surprisingly causes a reduction of the pressure, although the volume available for the filling compound of the mixer III is smaller than that of the mixer II the filling material available volume decreases, is the expectation that the pressure required to promote the filling material increases, since a smaller volume can expect a smaller free cross-sectional area and thus a stronger throttling effect. The change in the volume available for the filling mass is about 5% in this example. At the same time, this means that the proportion of losses corresponding to the volume in the mixer interior occupied by the filling material decreases by about 5%.

From the simulations has also shown that surprisingly further improvements in the mixing quality of the mixer III are possible. Each of the mixers IV, V, VI, VII has a higher mixing quality than the mixer III. This effect is due to the release elements, as in the embodiments according to Fig. 2a . Fig. 2b . Fig. 2c . Fig. 2d are shown. Surprisingly, both an improvement of the mixing quality is achieved and the pressure is reduced. Because of the improvement of the mixing quality, the volume can be reduced, that is, the loss proportion can be reduced. This means that the mixer can be operated according to one of the variants according to the invention with a lower pressure than the prior art and that the mixer has an equal or even smaller mixer length.

A comparison of all mixer types based on the mixing quality of the spiral mixer 0.035 results in the following table listed percentage improvements of mixers IV, V, VI, VII compared with mixer III. mixer Print [%] 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%

Accordingly, prior art mixers I and II provide significantly lower pressure and mixing volumes.

A comparison of all mixer types based on the pressure of the spiral mixer 2.80 results in the percentage improvements of mixers IV, V, VI, VII in comparison with mixer III listed in the table below. mixer Print [%] 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%

Accordingly, prior art mixers I and II provide significantly lower pressure and mixing volumes. In particular, the mixer IV is to be emphasized in this context, whose pressure is almost 50% lower than that of the structurally not very different mixer III.

Consequently, comparisons with mixers I and II provide further improvements. Thus, surprisingly, the provision of release elements can achieve both an improvement in the quality of mixing and a reduction in the pressure required to push and discharge the filling compound through the mixer.

Claims (15)

Mixing element for a static mixer for installation in a tubular mixer housing, wherein the mixing element has a longitudinal axis (10), along which a plurality of mounting bodies (1,101) are arranged one behind the other, wherein a first mounting body (1) has a first wall element (2), which extends in the direction of the longitudinal axis and has a first side wall (3) and a second side wall (4), which is arranged opposite the first side wall (3), wherein a deflecting element (11) is arranged adjacent to the first wall element (2) and the deflection element (11) has a deflection surface extending transversely to the first wall element (2) on both sides of the wall element (2), a first opening (12) in the deflection surface on the side, that of the first side wall (3) of the first wall element (2) is provided, wherein adjacent to the first opening (12) a second and a third wall element (8, 9) are arranged, wob ei 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) and each of the inner walls (81, 91) and outer walls (82, 92) enclose an angle between 20 ° and 160 ° to the first or second side wall (3, 4) of the first wall element (2), the first opening (12 ) between the inner walls (81, 91) of the second and third wall elements (8, 9) is arranged and a second opening (13, 14) outside one of the outer walls (82, 92) of the second or third wall element (8, 9) is, wherein the second opening (13, 14) in the deflection surface on the side facing the second side wall (4) of the first wall element (2) is provided, wherein the second and third wall element (8, 9) a first wall element (102) of a second mounting body (101) adjoins, wherein the first installation Body (1) with the second mounting body (101) via a common web element (15, 16, 17, 18) with each other connected is,
characterized in that
in addition to the said deflecting element (11) a detaching element (27, 28, 29, 30, 31) is provided, which is connected to the web element (15, 16, 17, 18), wherein the detaching element (27, 28, 29, 30 , 31) is formed as a projection which extends from an inner wall of the mixer housing transversely to the longitudinal axis (10) in a mixing space (20, 120). Mixing element according to claim 1, wherein the projection is formed as a bar or rib which at least partially an angle of more than 45 ° to the longitudinal axis of the mixer. Mixing element according to one of the preceding claims, wherein the projection is formed as a bar or rib, which is at least partially disposed substantially perpendicular to the longitudinal axis of the mixer. Mixing element according to one of the preceding claims, wherein the free cross-sectional area of the mixer housing is reduced by 5 to 12.5%, preferably 5 to 10%, by the detaching element. Mixing element according to one of the preceding claims, wherein the wall thickness of the detachment element differs by a maximum of 10%, preferably by a maximum of 5% of the average wall thickness of the wall elements or deflecting elements. Mixing element according to one of the preceding claims, wherein a plurality of release elements is provided, which are not arranged periodically recurring. Mixing element according to one of the preceding claims, wherein the release element is designed as a bar or rib, which extends at least partially on an inner wall of the bar member. Mixing element according to claim 7, wherein the release element is designed as a strip which extends from the web element to a deflection element. Mixing element according to one of the preceding claims, wherein the release element has an arm which projects into the mixing chamber. Mixing element according to claim 8, wherein the strip is connected to the web element and the deflecting element. Mixing element according to claim 8, wherein the web element and a further web element are connected to one another via the strip. Mixing element according to one of the preceding claims, wherein the second mounting body (101) has the first wall element (102) which extends in the direction of the longitudinal axis (10) and a first side wall (103) and a second side wall (104), which first side wall (103) is arranged opposite, wherein a deflecting element (111) adjacent to the first wall element (102) is arranged and the deflecting element (111) in the transverse direction to the wall element (102) on both sides of the wall element (102) extending deflection surface, wherein a first aperture (112) is provided in the diverter surface at the side facing the second side wall (104) of the wall member (102), adjacent to the first aperture (112) are second and third wall members (108, 108). 109), the second and third wall elements (108, 109) extending in the direction of the longitudinal axis (10), and an inner wall (181, 191) and an outer wall (182, 192) which extend substantially in the direction of the longitudinal axis (10) and each of the inner walls (181, 191) and outer walls (182, 192) is at an angle of between 20 ° and 160 ° to the first or second side wall (103, 104 ) of the first wall element (102), wherein the first opening (112) between the inner walls (181, 191) of the second and third wall elements (108, 109) is arranged and a second opening (113, 114) outside one of the outer walls ( 182, 192) of the second or third wall member (108, 109), the second opening (113, 114) being provided in the diverting surface on the side facing the second side wall (104) of the first wall member (102) is, where the second mounting body (101) containing the first wall element (102), the deflection element (111) and the second and third wall elements (108, 109) about the longitudinal axis (10) at an angle of 10 ° up to and including 180 ° with respect is arranged twisted on the first mounting body (1). Mixing element according to claim 12, wherein the second mounting body (101) has the same structure as the first mounting body (1) and / or the first mounting body (1) about the longitudinal axis (10) at an angle of 180 ° with respect to the second Installation body (101) is arranged twisted. Mixing element according to one of the preceding claims, wherein the web element (15, 16, 17, 18) on the outer circumference of the deflecting element (11, 111) is arranged. A static mixer comprising a mixing element according to any one of the preceding claims and a mixer housing surrounding the mixing element.

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