Static mixer

Abstract

The present invention relates to a static mixer (1) comprising a mixer housing (3), a mixer inlet (21) and a mixer element (19), wherein: the mixer element (19) is a helical mixer element (19) formed in one piece with the mixer inlet (21); the mixer element (19) and the mixer inlet (21) are axially fixed in place but can rotate inside the mixer housing (3); and the mixer housing (3) comprises an inlet portion (5) and a cylindrical mixing portion (7).

Description

[0001] Static mixer

[0002] The present invention relates to static mixers for mounting on a corresponding cartridge or dispensing device to mix and then dispense materials from it. These mixers operate passively, meaning they are not self-driven. The materials to be mixed are forced through them by an external force.

[0003] Such mixers typically comprise a mixer housing, a mixer inlet, and a mixer element. The mixer element is typically helical and integrally formed with the mixer inlet to create a single-piece mixer insert. The mixer element and the mixer inlet (i.e., the mixer insert) are axially fixed but rotatable within the preferably single-piece mixer housing. The mixer housing comprises an inlet section and a cylindrical mixing section.

[0004] There are many different designs for such mixers. Nevertheless, there is still room for improvement in the known designs.

[0005] Against this background, it is an objective of the present invention to present corresponding improvements or at least alternatives to conventional designs.

[0006] This problem is solved by the independent claims. Advantageous embodiments can be found in the dependent claims. According to a first aspect of the present invention, the mixer described in the introduction is characterized in that the mixer housing comprises at least one outer projection which extends radially outwards from the inlet section. From at least one such outer projection, an outer stop extends axially towards the mixing section of the mixer housing. This outer stop tapers along its axial length.

[0007] Preferably, the tapering of the outer stop comprises a reduction in the radial height and a reduction in the width of the outer stop.

[0008] Preferably, the reduction in radial height and / or the reduction in width of the outer stop extends only along an axial section of said outer stop.

[0009] Preferably, at least one external projection is provided, which is at least part of a bayonet fitting.

[0010] According to a second aspect of the present invention, the mixer described in the introduction is characterized in that at least one outer projection is formed on the outer surface of the mixer inlet at the level of the inlet section of the mixer housing in a radial direction. This outer projection abuts the inner surface of the inlet section of the mixer housing.

[0011] Preferably, the inner surface of the inlet section of the mixer housing is flat at the level of the projection. Specifically, the inner surface of the inlet section of the mixer housing does not include any recesses or projections with which the projection on the outer surface of the mixer inlet engages.

[0012] Alternatively, at least one inner recess and / or at least one inner projection is formed on the inner surface of the inlet section of the mixer housing in a radial direction, with which the projection on the outer surface of the mixer inlet engages. Preferably, the upper edge and / or the lower edge of the inner recess and / or the inner projection is chamfered to guide the mixer inlet.

[0013] Preferably, the inner recess and / or the inner projection extends along the entire inner circumference of the inlet section.

[0014] Preferably, the upper edge and / or the lower edge of the outer projection is chamfered to guide the mixer inlet.

[0015] Preferably, the outer projection extends along the entire outer circumference of the mixer inlet.

[0016] Preferably, the inlet section includes an inner collar. The mixer inlet preferably rests against said inner collar in the axial direction. Preferably, a sealing element is provided between the mixer inlet and said collar. The said inner collar preferably includes a chamfered inner surface for guiding the mixer inlet when inserted into the mixer housing.

[0017] According to a third aspect of the present invention, the mixer described above is characterized in that the mixer housing comprises a transition section which is provided between the inlet section and the mixing section of the mixer housing and connects them. The transition section has a substantially cylindrical outer surface, the diameter of which is larger than the diameter of the outer surface of the mixing section and smaller than the mean diameter of the outer surface of the inlet section.

[0018] Preferably, an inner recess and / or an inner projection is formed on the inner surface of the transition section of the mixer housing in a radial direction. The upper and / or lower edge of the inner recess and / or the inner projection is preferably chamfered to guide the mixer inlet. The inner recess and / or the inner projection preferably extends along the entire inner circumference of the transition section.

[0019] Preferably, at least one outer projection is formed on the outer surface of the mixer inlet at the level of the transition section of the mixer housing in a radial direction, which engages with the inner recess and / or the inner projection on the inner surface of the transition section of the mixer housing.

[0020] Preferably, the upper edge and / or the lower edge of the outer projection is chamfered to guide the mixer inlet.

[0021] Preferably, the outer projection extends along the entire outer circumference of the mixer inlet.

[0022] Preferably, the transition section includes an inner collar. The mixer inlet has an axial end surface which faces the inner collar but preferably does not touch it.

[0023] Preferably, two radially outwardly projecting wings are arranged on the outer surface of the mixer housing, in particular opposite each other and / or extending axially.

[0024] The two wings are preferably arranged on the mixing section of the mixer housing, and in particular at the end of the mixing section that is closest to the inlet section.

[0025] Preferably, said wings have a rounded upper edge. Preferably, said wings transition at their lower edge into the inlet section or into a transition section between the mixing section and the inlet section.

[0026] Preferably, the upper edge of the inlet section is chamfered.

[0027] Preferably, the upper edge of the transition section between the inlet section and the mixing section of the mixer housing is rounded.

[0028] Preferably, a sealing element, in particular in the form of an O-ring, is arranged on one or the inner collar of the inlet section and / or on one or the transition section between the inlet section and the mixing section of the mixer housing.

[0029] Preferably, the mixer inlet comprises two separate, in particular round, inlet openings. These inlet openings are preferably of the same or different sizes. Preferably, these inlet openings open into the mixing section of the mixer housing, preferably via a separate mixing chamber in the transition section between the inlet section and the mixing section of the mixer housing.

[0030] Preferably, the individual components of the mixer housing are connected to each other in a non-destructive and detachable manner and / or are essentially hollow cylindrical in design.

[0031] Preferably, the inlet section of the mixer housing is designed to engage directly with the outlet of an associated cartridge and / or a corresponding dispensing device in order to attach the static mixer to it. The three aspects of the present invention described above are not contradictory and can therefore be combined in any way.

[0032] Exemplary embodiments and functions of the present invention are described below with reference to the accompanying figures. These show:

[0033] FIG. 1 shows a perspective external view of an exemplary mixer according to the present invention;

[0034] FIG. 2 shows a vertical cross-section (FIG. 2a)) and two axial views (FIG. 2b) from above and FIG. 3c) from below) of a mixer similar to that of FIG. 1;

[0035] FIG. 3 shows an enlarged vertical cross-section of the lower part of the mixer from FIG. 2;

[0036] FIG. 4 shows a vertical cross-section (FIG. 4a)) and two axial views (FIG. 4b) from above and FIG. 4c) from below) of the mixer housing from FIG. 2;

[0037] FIG. 5 is an enlarged perspective external view of the inlet section of the mixer housing of FIG. 4;

[0038] FIG. 6 shows an axial cross-section of the transition section and the inlet section of the mixer housing of FIG. 4;

[0039] FIG. 7 a perspective view of a second exemplary mixer according to the present invention; and FIG. 8 a total vertical cross-section of a third exemplary mixer (FIG. 8a)) as well as a vertical cross-section of the lower region of the mixer (FIG. 8b)) and a vertical cross-section of the lower region of the associated mixer housing (FIG. 8c)).

[0040] As shown in FIG. 1, an exemplary embodiment of a static mixer 1 according to the invention comprises an elongated mixer housing 3 with an inlet section 5 and a cylindrical mixing section 7. The inlet section 5 and the mixing section 7 are connected to each other via a transition section 9. The inlet section 5, the mixing section 7, and the transition section 9 are each essentially hollow cylindrical and connected to each other in such a way that they cannot be separated from each other without damage. The mixer housing 3 is therefore a single-piece component.

[0041] As can be seen in FIG. 1, two radially outwardly projecting wings 11 are provided on the outer surface of the mixer housing 5, specifically on a radial outer surface of the mixing section 7 and on an axial outer surface of the transition section 9. These wings are identical and are positioned opposite each other. They serve as points of application for a user to exert a rotational force on the mixer housing 3. According to the illustrated embodiment, the two wings 11 can each have a rounded or chamfered upper edge. At their lower edge, they can transition into the transition section 9, or, if no such section is provided, into the inlet section 5.

[0042] In the present case, the mixer housing 3 comprises at least one external projection 13 with an external stop 15 at its inlet section 5. This projection extends towards the mixing section 7 of the mixer housing 3. The said external projection 13 can be designed as part of a bayonet fitting for coupling the inlet section 5 of the mixer housing 3 to an associated cartridge or dispensing device. As shown in FIG. 2, the static mixer 1 comprises, in addition to the mixer housing 3, a one-piece mixer insert 17 with a mixer element 19 and a mixer inlet 21. As will be described in detail below, the mixer insert 17 is axially fixed but rotatable in the mixer housing 3. The mixer element 19 is helically shaped and is located essentially in the region of the cylindrical mixing section 7 of the mixer housing 3.The mixer inlet 21 of the mixer insert 17 is located essentially in the area of ​​the inlet section 5 (and possibly the transition section 6) of the mixer housing 3.

[0043] The mixer housing 3 and the mixer insert 17 are designed such that they define a flow path along the longitudinal axis of the mixer, leading from the mixer inlet 21 to a mixer outlet 25. This flow path runs axially through the mixer housing 3 along the mixer insert 17. As shown, for example, in FIG. 2 c), the mixer inlet 5 comprises at least two, for example, round, inlet openings 27, which lead into a mixing chamber 29. The mixing chamber 29 is defined, for example, by the mixer inlet 5 itself or by the transition section 9 of the mixer housing 3 and opens into the mixing section 7 of the mixer housing 3.

[0044] Now, with reference to FIG. 3, we will discuss the specific design of the mixer inlet 21, the inlet section 5 and the transition section 9 of the mixer housing 3.

[0045] The inlet section 5 of the mixer housing 3 is provided with a circumferential inner recess 31 on its radial inner surface. Adjacent to this recess (specifically, directly below it), the inner surface of the inlet section 5 also includes a preferably radially circumferential inner projection 33. A preferably radially circumferential outer projection 35 is provided on the radial outer surface of the mixer inlet 21. This outer projection 35 of the mixer inlet 21 engages with the inner recess 31 and the inner projection 33 of the inlet section 5 of the mixer housing 3. This axially fixes the mixer insert 17 in the mixer housing 3 while still allowing relative rotation between the mixer insert 17 and the mixer housing 3.To guide the mixer insert 17 and to facilitate the insertion and / or removal of the mixer insert 17, the edges of said recess 31 and / or said projections 33 and 35 may be chamfered.

[0046] As can also be seen in FIG. 3, the transition section 9, like the inlet section 5 and the mixing section 7 in this case, has a substantially cylindrical outer surface. The diameter of the transition section 9 lies between that of the inlet section 5 and the mixing section 7. Analogous to the inlet section 5 described above, the transition section 9 can be provided with an inner recess 37 and / or an inner projection 39, while the mixer inlet 21 has a corresponding outer projection 41 which engages with the aforementioned inner recess 37 and / or the inner projection 39 of the transition section 9.

[0047] Reference is made here to FIG. 4, which shows only the mixer housing 3, i.e., the mixer 1 without the mixer insert 17. As can be clearly seen there, the upper edge of the inlet section 5 of the mixer housing 3 can be chamfered. The upper edge of the transition section 9 can be rounded.

[0048] FIG. 5 shows a perspective view of the inlet section 5 of the mixer housing 3 with the external projection 13 and the external stop 15 arranged thereon. As can be seen, the external stop 15 tapers along its axial length from the external projection 13 towards the mixing section 7 (upwards in FIG. 5a)). Specifically, the external stop 15 comprises a first (lower) section 15a with a constant radial height and circumferential width, and a second (upper) section 15b, which is ramp-shaped. The width of the second (upper) section 15b is constant and smaller than the circumferential width of the first (lower) section 15a.Between these two sections, a third (middle) section 15c is provided, which forms a smooth transition (once with and once without an intermediate section with a constant slope) between the first section 15a and the second section 15b. The individual sections 15a to 15c of the outer stop 15 are approximately the same length. The outer stop 15 has an axial length that is greater than its circumferential width and its radial height.

[0049] As can be seen particularly in FIG. 6, at least one of the inlet section 5 and the transition section 9 (preferably both) can comprise a radially inwardly projecting collar 42 or 43. The mixer inlet 21 can bear directly against at least one of these collars 42 or 43 in the axial direction, or a sealing element (not shown), for example in the form of an O-ring, can be provided to form an axial seal between the mixer insert 17 and the mixer housing 3. A certain distance or clearance can also be provided between one of the collars 42 and 43 and an axial end surface of the mixer inlet 21 in the assembled state of the mixer 1, which acts in particular as a mixing chamber 29 (see FIG. 2a)). The collars 42 and 43 can be chamfered, at least in part, as can be seen in FIG. 3.

[0050] As further shown in FIG. 7, the mixer housing 3 can be provided with ribs 45 in the area of ​​the two wings 11 and / or in the area of ​​the transition section 9. These increase the grip when coupling the mixer housing 3 with a corresponding cartridge (not shown) or dispensing device (not shown). This coupling is preferably effected via a bayonet fitting, of which the external projection 13 described above with the external stop 15 provided thereon can be a component. During the coupling process, generally, in the course of a substantially axial movement of the mixer 1, at least that part of the mixer inlet 21 which comprises the inlet openings 27 is inserted into corresponding receiving openings on the cartridge or dispensing device. In a separate, substantially rotary movement of the mixer housing 3 relative to the cartridge or dispensing device, the cartridge or dispensing device is then inserted into the corresponding receiving openings on the cartridge or dispensing device.The dispensing device (and the mixer insert 17, which is rotatably fixed relative to it) is locked with the provided bayonet fitting in order to connect the mixer 1 firmly but in a way that allows it to be removed without damage to the cartridge or dispensing device.

[0051] Finally, FIG. 8 shows an embodiment in which the inner surface of the inlet section 5 has no inner recess or projection that engages with the at least one outer projection 35 on the outer surface of the mixer inlet 21. In other words, the inner surface of the inlet section 5 of the mixer housing 3 is flat at the level of the outer projection. In the illustrated embodiment, two such projections 35 are formed. The upper of these outer projections 35 rests against the collar 42 of the inlet section 5.

[0052] The mixer inlet 21 is thus fixed in the mixer housing 3 only via the outer projection 41 described above at the level of the transition section 9, which engages with a corresponding inner recess 37 of the transition section 9 and / or a corresponding inner projection 39 of the transition section 9.

[0053] List of reference signs

[0054] 1 mixer

[0055] 3 mixer housings

[0056] 5 Entrance section

[0057] 7 Mixing section

[0058] 9 Transition section

[0059] 1 1 wing

[0060] 13 Outside lead

[0061] 15 External stop

[0062] 15a first section

[0063] 15b second section

[0064] 15c third section

[0065] 17 Mixer insert

[0066] 19 Mixer element

[0067] 21 Mixer inlet

[0068] 25 Mixer outlet

[0069] 27 Entrance opening

[0070] 29 Mixing chamber

[0071] 31 inner recess of the inlet section 5

[0072] 33 inner projection of the inlet section 5

[0073] 35 outer projection at the level of inlet section 5

[0074] 37 inner deepening of the transition section 9

[0075] 39 inner projection of the transition section 9

[0076] 41 outer projection at the level of transition section 9

[0077] 42 collars at entrance section 5

[0078] 43 collars at transition section 9

[0079] 45 ribs

Claims

Claims 1. Static mixer (1) with a mixer housing (3), a mixer inlet (21) and a mixer element (19), wherein the mixer element (19) is a helical mixer element (19) which is formed integrally with the mixer inlet (21), wherein the mixer element (19) and the mixer inlet (21) are arranged axially fixed but rotatably within the mixer housing (3), wherein the mixer housing (3) comprises an inlet section (5) and a cylindrical mixing section (7), characterized in that the mixer housing (3) comprises at least one outer projection (13) which extends radially outwards from the inlet section (5), wherein an outer stop (15) extends from at least one such outer projection (13) in the axial direction towards the mixing section (7) of the mixer housing (3), wherein the outer stop (15) tapers along its axial length.

2. Static mixer (1 ) according to claim 1 , wherein the tapering of the outer stop (15) comprises a reduction in the radial height and a reduction in the width of the outer stop (15).

3. Static mixer (1) according to claim 2, wherein the reduction of the radial height and / or the reduction of the width of the outer stop (15) occurs only along an axial section of the said external stop (15) extends.

4. Static mixer (1 ) according to one of the preceding claims, wherein at least one provided external projection (13) is at least part of a bayonet closure.

5. Static mixer (1 ) with a mixer housing (3), a mixer inlet (21 ) and a mixer element (19), wherein the mixer element (19) is a helical mixer element (19) which is formed integrally with the mixer inlet (21 ), wherein the mixer element (19) and the mixer inlet (19) are arranged axially fixed but rotatably within the mixer housing (3), wherein the mixer housing (3) comprises an inlet section (5) and a cylindrical mixing section (7), characterized in that at least one outer projection (35) is formed on the outer surface of the mixer inlet (21 ) at the level of the inlet section (5) of the mixer housing (3) in a radial direction, which abuts the inner surface of the inlet section (5) of the mixer housing (3).

6. Static mixer (1 ) according to claim 5, wherein the inner surface of the inlet section (5) of the mixer housing (3) is flat at the level of the projection (35).

7. Static mixer (1 ) according to claim 5, wherein at least one inner recess (31 ) and / or at least one inner projection (33) is formed on the inner surface of the inlet section (5) of the mixer housing (3) in a radial direction and the outer projection (35) engages with the inner recess (31 ) and / or the inner projection (33) on the inner surface of the inlet section (5) of the mixer housing (3).

8. Static mixer (1 ) according to claim 7, wherein the upper edge and / or the lower edge of the inner recess (31 ) and / or the inner projection (33) for guiding the mixer inlet (31 ) is chamfered and / or wherein the inner recess (31 ) and / or the inner projection (33) extends along the entire inner circumference of the inlet section (5).

9. Static mixer (1) according to one of the preceding claims 5 to 10. 8, wherein the upper edge and / or the lower edge of the outer projection (35) is chamfered for guiding the mixer inlet (21) and / or wherein the outer projection (35) extends along the entire outer circumference of the mixer inlet (21).

10. Static mixer (1) according to any one of the preceding claims 5 to 10. 9, wherein the inlet section (5) comprises a sump, wherein the mixer inlet (21) preferably abuts the inner collar (42) in the axial direction, wherein the inner collar (42) in particular comprises a chamfered inner surface for guiding the mixer inlet (21) when inserted into the mixer housing (3). 1 1. Static mixer (1 ) with a mixer housing (3), a mixer inlet (21 ) and a mixer element (19), wherein the mixer element (19) is a helical mixer element (19) which is formed integrally with the mixer inlet (21 ), wherein the mixer element (19) and the mixer inlet (21 ) are arranged axially fixed but rotatable within the mixer housing (3), wherein the mixer housing (3) comprises an inlet section (5) and a cylindrical mixing section (7), characterized in that the mixer housing (3) comprises a transition section (9) which is provided between the inlet section (5) and the mixing section (7) of the mixer housing (3) and connects them together, wherein the transition section (9) has a substantially cylindrical outer surface, the diameter of which is larger than the diameter of the outer surface of the mixing section (7) and smaller than the mean diameter of the outer surface of the inlet section (5).

12. Static mixer (1) according to claim 11, wherein an inner recess (37) and / or an inner projection (39) is formed on the inner surface of the transition section (9) of the mixer housing (3) in a radial direction, wherein the upper edge and / or the lower edge of the inner recess (37) and / or the inner projection (39) is preferably chamfered for guiding the mixer inlet (31), wherein the inner recess (37) and / or the inner projection (39) extends in particular along the entire inner circumference of the transition section (9).

13. Static mixer (1 ) according to claim 12, wherein at least one outer projection (41 ) is formed on the outer surface of the mixer inlet (21 ) at the level of the transition section (9) of the mixer housing (3) in a radial direction, which engages with the inner recess (37) and / or the inner projection (39) on the inner surface of the transition section (9) of the mixer housing (3).

14. Static mixer (1) according to claim 11 or 12, wherein the upper edge and / or the lower edge of the outer projection (41) is chamfered for guiding the mixer inlet (21) and / or wherein the outer projection (41 ) extends along the entire outer circumference of the mixer inlet (21 ).

15. Static mixer (1 ) according to one of claims 11 to 14, wherein the transition section (9) comprises an inner collar (9), wherein the mixer inlet (21 ) has an axial termination surface which is opposite the inner collar (9), but preferably does not touch it.

16. Static mixer (1 ) according to one of the preceding claims, wherein two radially outwardly projecting wings (1 1 ) are arranged on the outer surface of the mixer housing (3), in particular opposite each other and / or extending axially, wherein the two wings (1 1 ) are in particular arranged on the mixing section (79) of the mixer housing (3), preferably at the end of the mixing section (7) which is closest to the inlet section (5).

17. Static mixer (1 ) according to claim 16, wherein said wings (11 ) have a rounded upper edge and / or transition at their lower edge into the inlet section (5) or a, or the, transition section (9) between the mixing section (7) and the inlet section (5).

18. Static mixer (1 ) according to one of the preceding claims, wherein the upper edge of the inlet section (5) is chamfered and / or the upper edge of a, or of the, transition section (9) between the inlet section (5) and the mixing section (7) of the mixer housing (3) is rounded.

19. Static mixer (1 ) according to one of the preceding claims, wherein a sealing element, in particular in the form of an O-ring, is arranged on one, or the, inner collar (42, 43) of the inlet section (5) and / or one, or the, transition section (9) between the inlet section (5) and the mixing section (7) of the mixer housing (3).

20. Static mixer (1) according to one of the preceding claims, wherein the mixer inlet (21) comprises two separate, in particular round, inlet openings (27), which are in particular of the same or different sizes and, preferably via a separate mixing chamber (29) in a, or the, transition section (9) between the inlet section (5) and the mixing section (7) of the mixer housing (3), open into the mixing section (7) of the mixer housing (3).

21. Static mixer (1) according to one of the preceding claims, wherein the individual components (5, 7, 9) of the mixer housing (3) are connected to each other in a non-destructive and detachable manner and / or are essentially hollow cylindrical.

22. Static mixer (1 ) according to one of the preceding claims, wherein the inlet section (5) of the mixer housing (3) is designed to engage directly with the outlet of an associated cartridge and / or a corresponding dispensing device in order to attach the static mixer (1 ) to it.

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