EP2599540B1 - Mixing element for a static mixer and its use - Google Patents

Description

The invention relates to a mixing element for a static mixer made of plastic comprising a mounting body for installation in a tubular mixer housing. Such a mixer and the associated mixer housing can, as in the W02008113196 A1 be connected to the outlets of a multi-component cartridge and in their entirety constitute a cartridge arrangement, which in Fig. 2 of the WO2008113196 A1 is shown.

The mixing element, in particular its 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 in the interior of the mixer housing 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. As a 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 not yet been possible because the flow path from the injection point of the injection molding tool 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 tool internal pressures below 1000 bar, so that failure of the injection molding tool can be prevented. It should be noted that the installation bodies are preceded by an inlet element. The inlet member includes the two inlet channels which introduce the components from the cartridge outlets into the mixer housing. The mixing element contains mounting body. The components are deflected by the installation body, split and rejoined, resulting in a mixing of the components. At the outlet end of the mixer housing, the components are thus present as a uniformly mixed filling material.

The mixer of WO2008113196 A1 has a configuration, according to which a flow of a component is prevented by providing a constriction in the flow channel, so deliberately incorporates a throttle effect. Fig. 13 of WO2008113196 A1 shows that, for this purpose, a web element is provided in the inlet region of the mixer adjacent to its inlet channel, which forms a flow obstacle and ensures the deflection of the flow around this web element. The left side flowing component is thus imposed a longer flow path than the right side flowing component. According to a further embodiment, which in the EP0885651 A1 is shown, a divider is provided above each of the two inlet openings. This Divider is flowed around by the flowing through the respective inlet port component. Also in this embodiment, the volume flows of the two components are different. The first component with the larger volume flow is led to the separating web by web elements parallel to the outer surface of the adapter element in the direction of the inlet opening of the second component. The second component, which has a smaller volume flow, is detected by the first component and brought into contact before it enters the mixing element. This means that the first component with the larger volume flow reaches the mixer late in relation to the second component, ie its flow is delayed by additional path length.

In the document EP 0723 807 A2 shows a variant according to which the inlet chambers have different volumes when the components are present in a mixing ratio which is not equal to 1: 1. These inlet chambers receive the components conveyed from the cartridge before they enter the mixing element. The inlet chamber of the first component, which forms the larger volume flow, has a larger volume than the inlet chamber of the second component, which forms the smaller volume flow. When the first component thus enters the inlet chamber, first the inlet chamber is completely filled before the component reaches the first mixing element of the static mixer. The second component simultaneously flows through the second inlet chamber, which has a much smaller volume. The volume ratio can be adjusted so that the first component and the second component reach the first mixing element simultaneously.

Also according to the EP 0 584 428 the component which has a higher volume fraction is jammed. For this purpose, the flow path at the entrance of the static mixer is interrupted by a plate. In this plate, a slot-shaped opening is provided, through which the components which have filled the storage space in front, get into the static mixer. As a result, a flow of the component is prevented with the larger volume flow.

Generalizing, therefore, that the volumes that are between the cartridge and mixer should be adapted to the appropriate mixing ratios in order to obtain as little flow as possible in order to avoid that unusually mixed material is obtained. Therefore, the first approach is to adjust the cross-sectional areas of the leads according to the desired mixing ratio. However, if very different mixing ratios are present, the cross-sectional area for the component with the smaller volume flow is no longer producible. Therefore, an additional volume is made available to the component with the larger volume flow, for example, an inlet chamber as in the EP 0 723 807 A2 or a chamber at the inlet end of the mixing element, as in EP 0 584 428 A1 described.

Further mixing elements for static mixers are in the documents CH 699 958 and DE 101 64 385 described.

The object of the invention is to provide a mixing element in which each of the two components reaches the first mounting body of the mixing element in the desired mixing ratio. In particular, it is an object of the invention to reduce a flow of a component with respect to the other component. The leading component reaches the mixing element in front of the other component. Another object of the invention is to reduce the pressure loss in comparison to previously known solutions, which also have the problem of a flow.

The object of the invention is achieved by a mixing element which contains at least one installation body and an inlet element, which has a body with a first and a second inlet channel. Through the inlet channels, the corresponding components are guided separately to each other to the mounting body. In particular, a first and a second mounting body can be arranged behind one another along the longitudinal axis of the mixing element.

The inlet element is arranged upstream of the first installation body, wherein the inlet element and the installation body are connected to one another via a connecting element. The connecting element may be a helical element of a spiral mixer, which is at the same time its installation body or a web element which is part of the first installation body. The body of the inlet element is circumferentially in the mixer housing sealingly receivable. Each of the first inlet channels and the second inlet channels has an inlet opening and an outlet opening, so that the corresponding component can be guided through the corresponding inlet channel from the inlet opening to the outlet opening. The first inlet channel is spatially separated from the second inlet channel. The first inlet channel opens into an antechamber, wherein the antechamber is delimited by the outlet side of the body, the connecting element, the inner wall of the mixer housing and the first mounting body, wherein the second channel extends within the interior of the connecting element and opens from the connecting element into the first mounting body ,

The ratio of the remaining free cross-sectional area to the cross-sectional area of the continuation channel in a sectional plane that is normal to the longitudinal axis and located at the mixer inlet is at least 4: 1. The mixing ratio of the components can be 4: 1, but also according to an alternative embodiment, at least 5: 1, it can also be at least 10: 1, or even more. For all mixing ratios of the components, a mixing element with the same dimensions is preferably used. The following additional geometric conditions thus apply analogously for cross-sectional ratios of 5: 1 to 10: 1 or more. By "at least 4: 1" is intended to mean ratios of 4: 1, 5: 1, 6: 1, 10: 1, 20: 1 as well as intervening ratios or ratios which are above it. The mixer housing according to an embodiment has a shoulder on which the outlet side of the body rests. In particular, the cutting plane can be arranged between this shoulder and the first mounting body.

Immediately following the outlet opening, the cross-sectional area ratio of the cross-sectional areas available for the components at this point may be at least 5: 1. The ratio of the cross-sectional areas of the inlet openings is at least 5: 1.

The cross-sectional area of the inlet opening to the cross-sectional area adjacent to the outlet opening increases by at least twice for at least one of the components. In particular, the cross-sectional area from the inlet opening to the cross-sectional area following the outlet opening for each of the components at least doubles.

The mounting body can be formed here as a helical mixer, each helix can be regarded as an installation body. The helix is a web element, which is twisted around its longitudinal axis by an angle. The angle can be for example 90 °. An adjacent helix is then another mounting body. The helix can be arranged angularly offset from each other, in particular, adjacent helix can be arranged offset by an angle of 90 ° to each other. Alternatively, the mounting body of such a mixing element can be connected to one another via a common web element.

According to one embodiment, the second inlet channel narrows in the interior of the connecting element. By means of this constriction, the flow velocity of the second component, which flows through this second inlet channel in the operating state, can be increased. In particular, the second component may be admixed in a smaller amount than the first component flowing through the first inlet channel. The constriction ensures that the second component already enters the static mixer with the first component in the correct mixing ratio at the beginning of the discharge process.

The second inlet channel has in the interior of the connecting element on a clear diameter, which decreases continuously from the inlet side to the outlet side. When the clear diameter decreases continuously, For example, the flow rate may increase with minimal losses, that is, maximum increase in flow rate can be achieved.

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 member has a first sidewall and a second sidewall disposed opposite the first sidewall. The first wall element in particular forms the connecting element. A guide element may be arranged adjacent to the first wall element. The guide element can serve to extend the flow path of the first component, or to delay the inflow of the first component into the mixing element. The guide element may be formed as a deflecting element or formed as part of this deflecting element. The deflecting element has a deflecting surface extending transversely to the wall element on both sides of the wall element, a first opening being provided in the deflecting surface on the side facing the first side wall of the wall element. In particular, the deflecting element can at least partially cover the first outlet opening.

According to an exemplary embodiment, the first inlet channel at the respective outlet opening may have a cross-sectional area which differs from the cross-sectional area of the corresponding outlet opening of the second inlet channel. In particular, the cross-sectional area of the first inlet channel at the first outlet opening is greater than the cross-sectional area of the second outlet opening of the second inlet channel.

According to one embodiment, a second and a third wall element are arranged adjacent to the first opening, wherein the second and third wall elements extend in the direction of the longitudinal axis and each have 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. It has proven particularly advantageous if more than five mounting bodies are connected to one another via a common web element, because the pressure loss is surprisingly lower than without common web elements.

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, in turn, a second and a third wall element may be arranged, wherein the second and third wall elements extend in the direction of the longitudinal axis and each have 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 disposed 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 element, the second opening in the deflection surface on the side facing the second side wall of the first wall element is, can be provided.

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 can be provided, in particular, two web elements can 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 a curved at least partially in the direction of the flowing fluid surface for deflecting the fluid flow in a deviating from the longitudinal axis direction, in particular, a progressive curvature in the flow direction and in the direction of the mixer housing may be provided.

According to an alternative embodiment, the deflection surface may be substantially planar. In particular, the deflection surface may 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 facing the second side wall of the wall element may lie in a transverse plane which is oriented 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 process comprises the step of injecting a blowing agent-containing polymer into an injection mold at a cavity pressure of less than 600 bar, more preferably less than 500 bar.

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 with each other, so that a mixer assembly such 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 Mixture of a hardening mix of flowable components, such as the mixture of multi-component adhesives or sealants. Another preferred use is in the mixture of impression compounds in the dental field.

The components may be miscible in a ratio of 2: 1 to and at 20: 1, in particular 4: 1 to and 10: 1.

The static mixers described above are suitable as disposable mixers, since their manufacturing and material costs are low as soon as the corresponding injection molding tool 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. The multicomponent cartridge contains, in particular, two cartridge outlets for receiving and fluid-tight connection of the respective cartridge outlet with the inlet openings of a static mixing element according to one of the preceding embodiments as well as a holder for captively receiving the mixer housing.

Fig. 1

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

Fig. 2

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

Fig. 3a - 3d

Ansichten 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. 6a, 6b

Schnitte durch ein Einlassteil eines statischen Mischers und Mischelement gemäss Fig.3,

Fig. 7a, 7b

Schnitte durch das Mischergehäuse, das Mischelement sowie das Halteelement eines statischen Mischers nach einer der vorhergehenden Fig. im zusammengebauten Zustand,

Fig. 8

einen Schnitt durch das Mischelement auf der Höhe des Fortsetzungskanals,

Fig. 9

ein Detail von Fig. 8,

Fig. 10

einen Schnitt durch das Mischelement entlang der Auslassseite des Körpers,

Fig. 11

ein Detail von Fig. 9.

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. 2

an embodiment of a section of a mixing element according to a second embodiment of the invention,

Fig. 3a - 3d

Views 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. 6a, 6b

Sections through an inlet part of a static mixer and mixing element according to Figure 3 .

Fig. 7a, 7b

Cuts through the mixer housing, the mixing element and the holding element of a static mixer according to one of the preceding figures in the assembled state,

Fig. 8

a section through the mixing element at the level of the continuation channel,

Fig. 9

a detail of Fig. 8 .

Fig. 10

a section through the mixing element along the outlet side of the body,

Fig. 11

a detail of Fig. 9 ,

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 a liquid state or as flowable, in particular 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 food. 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 forms a flow cross-sectional area 22, in the direction of the installation 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 peripherally 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 the 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 the embodiment according to Fig. 1 90 °. According to Fig. 1 is the first wall element 2 with the second wall element 8 and the third wall element 9 via the deflecting element 11 connected. 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 "adjoining 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 arranged downstream of the first wall element 2 in the flow direction.

A second opening is provided in the deflection surface on the side facing the second side wall 4 of the wall element 2, the second or the third wall element 8, 9 adjoining 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 extend Outer walls 82, 92 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, a second and a third wall element 108, 109 are arranged in the direction of the longitudinal axis 10 opposite to the first wall element 102. That is, the second and third wall members 108, 109 are located downstream of the first wall member 102. The second and third wall members 108, 109 define a channel extending from the first opening 112 and extending in the direction of the longitudinal axis 10. A second opening 113, 114 is in the deflection surface on the side facing the first side wall 103 of the wall member 102 is provided. 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 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 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 mounting body 1 and the second mounting body 101 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. 2 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 with 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 shown with a reference line 36.

Fig. 3a to Fig. 3d each show a view of a first embodiment of a mixing element according to the invention. The mixing element 100 includes mounting bodies, as in Fig. 2 shown. All mounting bodies are connected to each other by web elements 15, 16, 17, 18. Furthermore, the mixing element 100 includes an inlet member 50 containing the inlet channels 51, 52 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. The components may be miscible in a ratio of 2: 1 to and at 20: 1, in particular 4: 1 to and 10: 1.

The inlet member 50 is disposed upstream of the first mounting body 1. The inlet element 50 and the mounting body 1 are connected to one another via a connecting element 60. The inlet element 50 has a body 57, which is sealingly receivable on the circumference in the mixer housing. The body 57 has a first inlet channel 51 and a second inlet channel 52. Each of the inlet channels 51, 52 has an inlet opening 53, 54 and an outlet opening 55, 56, so that the corresponding component can be guided through the corresponding inlet channel 51, 52 from the inlet opening 53, 54 to the outlet opening 55, 56. The first The first inlet channel 51 opens into an antechamber 58. The pre-chamber 58 is delimited by the outlet side 59 of the body 57, the connecting element 60, the inner wall of the mixer housing and the first mounting body, the second inlet channel 52 extends from the outlet opening 56 into an interior 61 of the connecting element 60. A continuation channel 62 opens from the interior 61 of the connecting element 60 into a mixing space 65 of the first mounting body 1.

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 99.

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. 6a and Fig. 6b show a section through an inlet member 50 of a static mixer and a mixing element 100 according to 3a to Fig. 3d , The static mixer includes a mixer housing 99 in which the mixing element 100 and the inlet member 50 are received. The mixer housing 99 is received in a holding element 98, which serves for connection to a cartridge, not shown here. Fig. 6a shows a longitudinal section through the static mixer, which is placed along the longitudinal axis 10. The cut is made such that the nozzle 63, which contains the inlet channel 51, is not visible, because this nozzle 63 comes to lie in front of the plane of the drawing. The nozzle 64, which contains the inlet channel 52, is visible.

The cap member 66, which is part of the body 57 of the inlet member, is held in the mixer housing. Through the cap member 66 extend the inlet channels 51, 52, which in Fig. 6b is visible. The cap member 66 may include a circumferential projection 72 extending along the skirt 71 of the cap member 66. The projection 72 is received in a corresponding recess 97 of the mixer housing 99. The cap member 66 can be held captive in the mixer housing 99. However, rotation of the cap member 66 relative to the mixer housing 99 is possible to ensure that the mixing element 50 can be correctly placed on the outlets of the cartridge. For this purpose, the connecting pieces 63, 64 are placed on the corresponding outlets or inserted into the corresponding outlets, so that the connecting pieces 63, 64 enclose the outlets or the outlets enclose the connecting pieces 63, 64.

A flange member 67 serves as a support for the mixer housing 99. The mixer housing 99 is constructed in two stages. The inlet part 96 of the mixer housing 99 has a larger inner diameter than the main part 95 of the mixer housing. The main part 95 of the mixer housing 99 the fitting body of the mixing element, the inlet part 96 includes the cap member 66 of the body 57 of the inlet member 50. The flange member is also received in a holding member 98. The flange member 67 also forms the support of the end of the inlet part 96 of the mixing element. The retaining member 98 serves to secure the static mixer to the cartridge. Usually, the holding element 98 is provided for this purpose with Bayonettbefestigungsmitteln.

The inlet channel 51 extends within the nozzle 63 and continues through the flange 67 into the cap member 66. The inlet channel 51 thus begins at the inlet opening 53 and ends at the outlet opening 55. The inlet channel 52 extends inside the nozzle 64 and continues through the flange element 67 into the cap element 66. The inlet channel 52 thus begins at the inlet opening 54 and ends at the outlet opening 56. From the inlet channel 52, a continuation channel 62 leads into the interior 61 of the connecting element 60. The connecting element 60 can be designed in particular as the first wall element of the first installation body 1. In particular, the second inlet channel 52 in the interior 61 of the connecting element 60 can narrow. The second inlet channel 52 extends in the interior 61 of the connecting element 60 from an inlet side 75 to an outlet side 76. The inlet channel 52 has a clear diameter, which decreases continuously from the inlet side 75 to the outlet side 76.

Between the first outlet opening 55 and the connecting element 60, a guide element may be provided in the prechamber 58. This guide is not shown in the drawing. The guide element may be formed, for example, as a weir element. The emerging from the outlet opening 55 component is deflected along this weir element and divided. This weir element may be bar-shaped. An example of such a defense element can be found in EP0885651 A1 , there referred to as the separating edge. In particular, the guide element may at least partially cover the first outlet opening 55.

The first inlet channel 51 of the inlet element 50 has at the outlet opening 55 a cross-sectional area which differs from the cross-sectional area of the second inlet channel 52 at the outlet opening 56. Such an inlet element 50 is used for components which are miscible in a ratio of 2: 1 to and at 20: 1, in particular 4: 1 to and 10: 1.

Fig. 7a and Fig. 7b each show a section through a complete mixing element 100, which is received in the mixer housing 99. The mixer housing 99 is constructed of an inlet part 96 and a main part 95. The inlet part 96 contains the inlet member 50 of the mixing element 100. The main part 95 contains the mounting bodies 1, 101 of the mixing element 100. The mixer housing has an inlet end 94 and an outlet end 93. Two or more components enter the mixer housing via the inlet element separated from each other and are brought into contact with each other in the first installation body 1. The wall elements of the installation body serve for the division of the component flow and the deflection elements of the deflection of the component flow, that is, the bringing about of a local redeployment of the component flow. By continuing over the length of the mixing element division and deflection of the component flow, the components are mixed. At the outlet end 93 of the mixer housing 99 exits a homogeneous filler.

The web elements 15, 16, 17, 18 hold all the mounting body of the mixing element 100 connected to each other. 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 in the operation of the mixer to break the mixing element, 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 be exclusive in the common cut surface and a possible reinforcement of the same. That is, the cut surface in this case consists of two squares, which would have a side length corresponding to the wall thickness 7. 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, in accordance with a preferred embodiment, the web elements for forwarding the polymer melt in the production process are provided by an installation body to each of the adjacent installation bodies.

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.

Fig. 8 shows a section through the mixing element at the level of the continuation channel. The cut contains the holding element 98 in a partially cut-away form with the coding elements and the parts of a bayonet closure, by means of which the holding element 98 can be connected to a multi-component cartridge. Within the holding element 98, the cap member 66 is arranged, which is part of the mixer housing 99. The cap member 66 has a centrally located circular opening 70 in which the connecting element 60 is received. The connecting element 60 does not completely fill the opening, but has two recesses which form the interior of the connecting element 61. These recesses are in Fig. 10 shown in detail. The recesses are the fluid-carrying channels through which the components to be mixed are supplied to the installation bodies of the mixing element.

Fig. 9 shows a detail of Fig. 8 , namely the opening 70 in the cap member 66. In the opening 70 is the connecting element 60, which contains two recesses 73, 74, which form the interior of the connecting element 61. The recess 73 is provided for the component with the larger volume flow, the recess 74 serves as a channel for the component with the smaller volume flow. The recess 74 thus represents a section through the continuation channel 62. According to a preferred embodiment, the ratio of the cross-sectional areas of the recess 73 to the recess 74, ie the ratio of the remaining free cross-sectional area to the cross-sectional area of the continuation channel 62 is between 4: 1 and 5: 1. In particular, the cross-sectional area of the recess 73 is 2.8 mm ² and the cross-sectional area of the recess 74 is 0.6 mm ² .

Fig. 10 shows a section through the mixing element along the outlet side of the body 57, which the inlet channels 51, 52 (see Fig. 6b ) contains. The outlet opening 55 of the inlet channel 51 opens into the antechamber 58, which extends between the connecting element 60 and the outlet side 59 of the body 57. The outlet opening 56 of the inlet channel 52 is separated by the outlet side 59 forming wall elements 77 of the prechamber 58, so that the two components in the prechamber not yet in Come in contact. The wall elements 77 which define the connecting channel 78 leading to the connecting element 60 are in FIG Fig. 11 shown in detail. The ratio of the cross-sectional areas of the pre-chamber 58 to the connecting channel 78 as shown in the present section, is at least 5: 1, wherein in the prechamber 58, the component with the larger volume flow is included. In particular, according to one exemplary embodiment, the cross-sectional area of the pre-chamber may be 32.4 mm ² , the cross-sectional area of the connecting channel 78 may be 6.2 mm ² . The cross-sectional area of the outlet opening 55 belonging to the inlet opening 53, the in Fig. 6b is shown, then is 15.9 mm ² . The cross-sectional area of the exit opening 56 associated with the inlet opening 54 in Fig. 6b is shown, then is 2.8 mm ² . For this embodiment, the volume of the two components in the inlet region, that is, from the corresponding inlet opening 53, 54 to the entry into the first mounting body of the mixing element for the component with the larger volume flow is 171 mm ³ and for the component with the smaller volume flow 28 mm ³ . This corresponds to a ratio of approximately 6: 1.

Fig. 11 shows a detail of Fig. 10 , namely the wall elements 77, which bound the connecting channel 60 leading to the connecting element 60. In particular shows Fig. 11 in that the connecting channel 78 is narrowed from the outlet opening 56 until it enters the interior of the connecting element 61. This constriction can be done in particular by at least partially conical channel walls.

The ratio of the cross-sectional area of the continuation channel and the remaining free cross-sectional area in a sectional plane which is normal to the longitudinal axis and located at the mixer inlet is at least 4: 1. The mixing ratio of the components can be 4: 1, but also according to an alternative embodiment, at least 5: 1, it can also be at least 10: 1, or even more. For all mixing ratios of the components is preferably a Used mixing element with the same dimensions. The following additional geometric conditions thus apply analogously for cross-sectional ratios of 5: 1 to 10: 1 or more.

The mixer housing according to an embodiment has a shoulder on which the outlet side of the body rests. In particular, the cutting plane can be arranged between this shoulder and the first mounting body.

Immediately following the outlet opening, the cross-sectional area ratio of the cross-sectional areas available for the components at this location may be at least 5: 1. The ratio of the cross-sectional areas of the inlet openings is at least 5: 1.

The cross-sectional area of the inlet opening to the cross-sectional area adjacent to the outlet opening increases by at least twice for at least one of the components. In particular, the cross-sectional area from the inlet opening to the cross-sectional area following the outlet opening for each of the components at least doubles.

Claims (15)

1. A mixing element (100) for a static mixer for installation into a tubular mixer housing (99), wherein the mixing element has a longitudinal axis (10) along which at least one first and one second installation body (1, 101) are arranged behind one another, wherein an inlet element (50) is provided which is arranged upstream of the first installation body (1), wherein the inlet element (50) and the first installation body (1) are connected to one another via a connection element (60), wherein the inlet element (50) has a body (57) which can be sealingly taken up peripherally in the mixer housing (99), wherein the body (57) has a first inlet passage (51) and a second inlet passage (52), wherein the first inlet passage (51) has a first entry opening (53) and a first exit opening (55), wherein the second inlet passage (52) has a second entry opening (54) and a second exit opening (56) so that the corresponding component can be conducted through the corresponding inlet passage (51, 52) from the entry opening (53, 54) to the exit opening (55, 56) and the first inlet passage (51) extends spatially separately from the second inlet passage (52), wherein the first inlet passage (51) opens into a pre-chamber (58), wherein the pre-chamber (58) is bounded by the outlet side (59) of the body (57), by the connection element (60), by the inner +wall of the mixer housing as well as by the first installation body (1), wherein the second inlet passage (52) extends from the exit opening (56) into an inner space (61) of the connection element (60) and a continuation passage (62) opens into a mixing space (65) of the first installation body (1) from the inner space (61) of the connection element (60), wherein the ratio of the cross-sectional area of the continuation passage and of the remaining free cross-sectional area in a sectional plane which is laid normal to the longitudinal axis and is arranged at the mixer entry amounts to at least 4:1.
2. A mixing element in accordance with claim 1, wherein the second inlet passage (52) constricts in the inner space (61) of the connection element (60).
3. A mixing element in accordance with claim 1 or claim 2, wherein the second inlet passage (52) extends in the inner space (61) of the connection element (60) from an entry side (75) to an exit side (76), wherein the second inlet passage (52) has an inner diameter which reduces continuously from the entry side (75) up to the exit side (76).
4. A mixing element in accordance with any one of the preceding claims, wherein, directly adjoining the entry opening (55, 56), the cross-sectional area ratio of the cross-sections available for the components at this point amounts to at least 5:1.
5. A mixing element in accordance with any one of the preceding claims, wherein the ratio of the cross-sectional areas of the entry openings is at least 5:1.
6. A mixing element in accordance with any one of the preceding claims, wherein the cross-sectional area of the inlet opening to the cross-sectional area adjoining the outlet opening (55) increases by at least double for at least one of the components.
7. A mixing element in accordance with any one of the preceding claims, wherein the first installation body (1) has a first wall element (2) which extends in the direction of the longitudinal axis (10) and has a first side wall (3) and a second side wall (4) which is arranged opposite the first side wall (3), wherein the first wall element (2) forms the connection element (60).
8. A mixing element in accordance with any one of the preceding claims, wherein a deflection element (11) is arranged adjacent to the first wall element (2) and the deflection element (11) has a deflection surface extending in the transverse direction to the first wall element (2) at both sides of the wall element (2), wherein a first opening (12) is provided in the deflection surface at the side which faces the first side wall (3) of the first wall element (2), wherein a second and a third wall element (8, 9) are arranged adjacent to the first opening (12), wherein 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) include an angle between 20° and 160° with the first or second side wall (3, 4) of the first wall element (2), wherein the first opening (12) is arranged between the inner walls (81, 91) of the second and third wall elements (8, 9) and a second opening (13, 14) is arranged outside one of the outer walls (82, 92) of the second or third wall element (8, 9), wherein the second opening (13, 14) is provided in the deflection surface at the side facing the second side wall (4) of the first wall element (2), wherein a first wall element (102) of a second installation body (101) adjoins the second and third wall element (8, 9).
9. A mixing element in accordance with any one of the preceding claims wherein the second installation body (101) has the first wall element (102) which extends in the direction of the longitudinal axis (10) and has a first side wall (103) and a second side wall (104) which is arranged opposite the first side wall (103), wherein a deflection element (111) is arranged adjacent to the first wall element (102) and the deflection element (111) has a deflection surface extending in the transverse direction to the wall element (102) at both sides of the wall element (102), wherein 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), wherein a second and third wall element (108, 109) are arranged adjacent to the first opening (112), wherein the second and third wall elements (108, 109) extend in the direction of the longitudinal axis (10) and each have 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) include an angle between 20° and 160° with the first or second side walls (103, 104) of the first wall element (102), wherein the first opening (112) is arranged between the inner walls (181, 191) of the second and third wall elements (108, 109) and a second opening (113, 114) is arranged outside one of the outer walls (182, 192) of the second or third wall elements (108, 109), wherein the second opening (113, 114) is provided in the deflection surface at the side which faces the second side wall (104) of the first wall element (102), wherein 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° with respect to the first installation body (1).
10. A mixing element in accordance with any one of the preceding claims, wherein more than five installation bodies are connected to one another via a common bar element (15, 16, 17, 18).
11. A static mixer containing a mixing element (100) in accordance with any one of the preceding claims and a mixer housing (99) which surrounds the mixing element.
12. A multicomponent cartridge which has two cartridge outlets for the reception and fluid-tight connection of the respective cartridge outlet to the entry openings (53, 54) of a mixing element (100) in accordance with any one of the preceding claims 1 to 10 as well as a holding element (98) for the captive reception of the mixer housing (99).
13. A multicomponent cartridge in accordance with claim 12 for components which can be mixed in a ratio from 2:1 up to and including 20:1, in particular 4:1 up to and including 10:1.
14. Use of a mixing element in accordance with any one of the preceding claims 1 to 10 for mixing flowable components.
15. Use of a mixing element in accordance with any one of the preceding claims 1 to 10 for mixing multicomponent adhesives, sealing materials or dental impression materials.

Images