STATIC MIXER

Abstract

The present invention relates to a static mixer for mixing together at least two components. The static mixer comprises a mixer housing; a mixing element having an upstream end with at least two entry openings and a downstream end, the mixing element being arranged at least partly within the mixer housing; a mixing head having at least two inlets provided at an input side and at least two outlets provided at an output surface, wherein each of the at least two inlets is in fluid communication with one of the at least two outlets; and a separating wall disposed between the output surface and the upstream end of the mixing element for separating the components leaving the outlets.

The separating wall comprises a free downstream edge which is disposed with respect to at least one of the entry openings so as to allow at least partial flows of the components separated by the separating wall to combine after exceeding the downstream edge and to jointly enter said at least one of the entry openings.

Claims

1. A static mixer for mixing together at least two components comprising: a mixer housing; a mixing element having an upstream end with at least two entry openings and a downstream end, the mixing element being arranged at least partly within the mixer housing; a mixing head having at least two inlets provided at an input side and at least two outlets provided at an output surface, wherein each of the at least two inlets is in fluid communication with one of the at least two outlets; and a separating wall disposed between the output surface and the upstream end of the mixing element for separating the components leaving the outlets, wherein the separating wall comprises a free downstream edge which is disposed with respect to at least one of the entry openings so as to allow at least partial flows of the components separated by the separating wall to combine after exceeding the downstream edge and to jointly enter said at least one of the entry openings.

2. The static mixer according to claim 1, wherein the separating wall has a meandering pattern.

3. The static mixer according to claim 1, wherein the separating wall comprises at least two segments that are in parallel to each other.

4. The static mixer according to claim 1, wherein the separating wall comprises the following segments in the stated order: a curved segment, a linear segment, a linear or curved segment, a linear segment and a curved segment.

5. The static mixer according to claim 1, wherein the separating wall comprises thickened segments for reducing a volume accessible for the components when leaving the outlets.

6. The static mixer according to claim 1, wherein the separating wall at least partially frames at least one of the at least two outlets and/or at least one of the at least two entry openings.

7. The static mixer according to claim 1, wherein the separating wall is integrally formed with the mixing element and/or with the mixing head.

8. The static mixer according to claim 1, wherein the separating wall, the mixing head, and the mixing element are a one-piece construction.

9. The static mixer according to claim 8, wherein the one-piece construction is formed by injection molding.

10. The static mixer according to claim 1, further comprising an intermediate wall disposed between the upstream end of the mixing element and the separating wall.

11. The static mixer according to claim 1, wherein the intermediate wall traverses at least one linear segment of the separation wall at an angle of between 70 and 110.

12. The static mixer according to claim 11, wherein the intermediate wall traverses at least one linear segment of the separation wall at an angle of between 80 and 100.

13. The static mixer according to claim 11, wherein the intermediate wall traverses at least one linear segment of the separation wall at an angle of between 85 and 95.

14. The static mixer according to claim 11, wherein the intermediate wall traverses at least one linear segment of the separation wall at an angle of approximately 90.

15. The static mixer according to claim 1, further comprising at least one flow obstruction disposed between the upstream end of the mixing element and the output surface for deflecting the components or at least partial flows of the components.

16. The static mixer according to claim 15, wherein the at least one flow obstruction is disposed between the downstream edge of the separating wall and the upstream end of the mixing element or is essentially disposed in one plane with the downstream edge of the separating wall.

17. The static mixer according to claim 1, wherein the mixing element comprises a plurality of mixer elements arranged one after another for a repeated separation and re-combination of streams of the components to be mixed.

18. The static mixer according to claim 17, wherein the mixing element comprises mixer elements for separating the material to be mixed into a plurality of streams, as well as means for the layered merging of the same, including a transverse edge and guide walls that extend at an angle to said transverse edge, as well as guide elements arranged at an angle to a longitudinal axis and provided with openings, wherein said mixing element comprises a transverse edge and a following transverse guide wall and at least two guide walls ending in a separating edge each with lateral end sections and with at least one bottom section disposed between said guide walls, thereby defining at least one opening on one side of said transverse edge and at least two openings on the other side of said transverse edge.

19. The static mixer according to claim 17, wherein the mixing element comprises mixer elements for separating the material to be mixed into a plurality of streams, as well as means for the layered merging of the same, including separating edges and a transverse edge that extends at an angle to said separating edges, as well as deflecting elements arranged at an angle to the longitudinal axis and provided with openings, wherein said mixing element comprises at least two separating edges with following guide walls with lateral end sections and with at least one bottom section disposed between said guide walls, and a transverse edge arranged at one end of a transverse guide wall, thereby defining at least one opening on one side of said transverse edge and at least two openings on the other side of said transverse edge.

20. A dispensing apparatus comprising a multi-component cartridge and the static mixer according to claim 1 connected to the multi-component cartridge.

21. The dispensing apparatus according to claim 20, wherein the multi-component cartridge is filled with respective components.

22. Use of the static mixer in accordance with claim 1 to dispense components from a multi-component cartridge via the static mixer.

23. Use of the dispensing apparatus in accordance with claim 20 to dispense components from the multi-component cartridge via the static mixer.

Description

[0045] Further embodiments of the invention are described in the following description of the figures. The invention will be explained in the following in detail by means of embodiments and with reference to the drawing in which is shown:

[0046] FIG. 1a a side view of a static mixer according to the invention;

[0047] FIG. 1b the static mixer from FIG. 1a rotated by 90 to the left;

[0048] FIG. 2 a cross-sectional view along the section line A-A of the static mixer of FIG. 1a,

[0049] FIG. 3a a perspective part view of the static mixer of FIGS. 1a, 1b;

[0050] FIG. 3b the static mixer from FIG. 3a rotated by 180;

[0051] FIGS. 4a, 4b, 4c perspective cross-sectional views along the section line C-C of the static mixer of FIG. 1b;

[0052] FIGS. 5a, 5b, 5c perspective cross-sectional views of the separating wall of three further embodiments of a static mixer according to the invention;

[0053] FIG. 6 an enlarged cross-sectional view of FIG. 4b with indicated flow paths; and

[0054] FIG. 7 a simplified cross-sectional view along the entry plane of the entry openings.

[0055] In the following the same reference numerals will be used for parts having the same or equivalent function. Any statements made having regard to the direction of a component are made relative to the position shown in the drawing and can naturally vary in the actual position of application.

[0056] FIG. 1a shows a side view of a static mixer 10 with a longitudinal axis A.sub.L comprising a mixer housing 12, a mixing element 14, an intermediate wall 36, a separating wall 32 and a mixing head 22. The mixer housing 12 is indicated by a dashed line and comprises a shoulder 13 separating a wider housing section 11 from a tube-like narrow housing section 15. Apart from the mixer housing 12, the static mixer 10 is a one-piece construction fabricated by injection molding. FIG. 1b shows the static mixer 10 rotated by 90 to the left about the longitudinal axis A.sub.L.

[0057] The mixing element 14 and part of the mixing head 22 are arranged within the mixer housing 12. The mixer housing 12, in particular the wider housing section 11, can further comprise a connection element for establishing a connection to a cartridge (not shown). For example, the connection element can be a sleeve in which the narrow housing section 15 can be received. The sleeve can have an internal thread for establishing a screwed joint and/or means for establishing a bayonet coupling to the cartridge. Further, the mixing head and/or the sleeve can be provided with connection means for establishing a plug connection with the cartridge.

[0058] The mixing head 22 has two inlets 24a, 24b provided at an input side 26. Each of the two inlets 24a, 24b is in fluid communication with a corresponding outlet 28a, 28b provided at an output surface 30. The inlets 24a, 24b are of the same size as the outlets 28a, 28b. The inlets 24a, 24b are of the same size as the outlets 28a, 28b. Also, the inlets 24a, 24b and the outlets 28a, 28b among each other are of the same size. Further, a flow channel defined by inlet 24a and outlet 28a has the same volumetric capacity as a corresponding flow channel defined by inlet 24b and outlet 28b.

[0059] The separating wall 32 is arranged between the output surface 30 and the intermediate wall 36. The separating wall 32 partly surrounds the outlet 28b and comprises two thickened segments 35 and further segments 34a, 34b, 34c (see FIGS. 3 and 4). Being arranged in one plane with a downstream edge 33 of the separating wall 32, the static mixer further comprises flow obstructions 40a, 40b which partly overlap with the openings 28a or 28b (see FIGS. 3 and 4).

[0060] The intermediate wall 36 is located at an upstream end 16 of the mixing element 14 and is disposed between the separating wall 32 and a first mixer element 42. The intermediate wall 36 traverses the separating wall 32 and defines two sides 38a, 38b, wherein the side 38a is assigned to the outlet 28a of the mixing head 22 and to two entry openings 20a, 20b of the mixing element 14. The side 38b is assigned to outlet 28b and one entry opening 20c. This becomes more obvious in FIG. 2.

[0061] The mixing element 14 comprises several successive mixer elements 42, wherein each mixer element 42 comprises a transverse guide wall 45 with a transverse edge 44, followed by two guide walls 46a, 46b each extending at a 90 angle to the transverse guide wall 45 and each having a separating edge 48. A bottom section 50 having a bottom edge 51 at its lower side is disposed between the two guide walls 46a, 46b. The bottom edge 51 divides the lower side of the bottom section 50 into two sloping parts 49a, 49b. Further, each of the guide walls 46a, 46b has one lateral end section 52a, 52b. Thereby three openings for the components to pass through are defined. One opening is defined on a side 54b of the transverse edge 44 and two openings are defined on a side 54a of the transverse edge 44. The arrangement of the openings corresponds to the arrangement of the entry openings 20a, 20b, 20c, which is why the sides 56a, 56b and the sides 38a, 38b defined by the intermediate wall 36 essentially correspond to each other. The arrangement of the openings becomes more obvious from FIG. 2.

[0062] The individual successive mixer elements 42 are connected to one another by struts 56, with the struts 56 also acting as further guide walls. The number of mixer elements 42 and the corresponding length of the struts 56 is selected in dependence on the kind of material that is to be dispensed with a certain static mixer 10. For some applications five mixer elements 42 may be sufficient whereas for others ten or more mixer elements 42 may need to be connected to one another by means of struts 56. An outer surface of the struts 56 has the same curvature as an inner surface of the mixer housing 12 and the struts 56 make direct contact to the mixer housing 12.

[0063] FIG. 2 shows a cross-sectional view of the static mixer 10 of FIG. 1 (along section line A-A) thereby indicating the arrangement of the openings 20a, 20b, 20c. The openings 20a, 20b are arranged on the side 38a of the intermediate wall 36, whereas the opening 20c is arranged on the side 38b. The sloping part 49a of the bottom section 50 being arranged between the guide walls 46a, 46b (indicated by dashed lines) is flanked by opening 20a. The sloping part 49b of the bottom section 50 is flanked by opening 20b. The opening 20c is flanked by the lateral end sections 52a, 52b of the guide walls 46a, 46b. The openings 20a, 20b, 20c represent three flow paths for the components to be mixed, wherein the inner surface of the mixer housing 12 partially forms part of these flow paths by forming an outer guide wall.

[0064] The cross-section according to FIG. 2 could have been also made along section line B-B, whereby the holes 20a, 20b then would have been separated from hole 20c by the transverse guide wall 45.

[0065] FIG. 3a shows a perspective part view of the static mixer 10. FIG. 3b shows the same mixer 10 rotated by 180 about the longitudinal axis A.sub.L. Both views in particular illustrate the arrangement of the flow obstructions 40a, 40b as well as the arrangement of the separating wall 32. The mixer housing 12 has been omitted to provide a better overview.

[0066] The separating wall 32 comprises two thickened segments 35 arranged at a periphery of the output surface 30. Both thickened segments 35 are followed by curved segments 34a which both extend to an edge of the outlet 28a. From here two linear segments 34b follow which both extend to an edge of the outlet 28b. The linear segments 34b are interconnected by a curved segment 34c which partly surrounds the outlet 28b. The outlets 28a, 28b hence are separated by the separating wall 32. The separating wall 32 in cooperation with the output surface 30, with the shoulder 13 (see FIGS. 1a, 1b) being in direct contact with an upper side of the thickened segments 35 and with the wider section 11 of the mixer housing 12 defines distinct volumes accessible for both components after leaving the outlets 28a, 28b. The volume assigned to the outlet 28a is essentially the same as the volume assigned to the outlet 28b. The volume assigned to the outlets 28a, 28b can be adjusted by varying the size and position of the thickened segments 35.

[0067] The flow obstruction 40a has a plane lenticular shape and partly overlaps with the outlet 28a (see also FIG. 4a). The flow obstruction 40a further comprises an outer rim 41 supporting the shoulder 13 of the mixer housing 12 (see FIGS. 1a, 1b). It becomes clear that the narrow housing section 15 surrounds the mixing element 14 and the intermediate wall 36. The flow obstruction 40b likewise has a plane lenticular shape and partly overlaps with the outlet 28b (see also FIG. 4a). Also the flow obstruction 40b comprises a rim 41 for supporting the shoulder 13 of the mixer housing 12. The flow obstructions 40a, 40b ensure that the components leaving the outlets 28a, 28b foremost occupy the volume defined by the separating wall 32 in cooperation with the shoulder 13 of the mixer housing 12 and its wider section 11 before they proceed beyond the downstream edge 33.

[0068] FIGS. 4a, 4b, 4c respectively show a cross-sectional perspective part view (along section line C-C of FIG. 1b) of the static mixer 10. The mixer housing 12 has been omitted to provide a better overview. The meandering pattern of the separating wall 32 comprising the two thickened segments 35, three curved segments 34a, 34c and two linear segments 34b being aligned parallel to each other becomes clearly visible. Moreover, it is shown that the intermediate wall 36 traverses the two linear segments 34b of the separating wall 32 at an angle of approximately 90. In FIGS. 4a and 4b the course of the separating wall 32 beneath the flow obstructions 40a, 40b and the intermediate wall 36 is indicated by a dashed line. Further, it becomes clear that approximately two fifth of the openings 28a, 28b overlap with a cross-sectional area of the tube-like narrow housing section 15 (see FIGS. 1a, 1b) The cross-sectional area of the narrow housing section 15 is defined by the rims 41 which lie on the circumference of an imaginary circle. In other embodiments the overlap of the openings 28a, 28b with the narrow housing section 15 can be set within a range of between one fifth and one half.

[0069] FIGS. 5a, 5b, 5c respectively show a cross-sectional perspective part view of a static mixer according to the invention. The static mixers 10 depicted in FIGS. 5a, 5b, 5c differ from each other in the design of the separating wall 32. The shape of the different separating walls 32 becomes clearly obvious. In FIG. 5a the separating wall 32 comprises two thickened segments 35 respectively followed by a curved segment 34a and a linear segment 34b. The two linear segments 34b being arranged inclined to each other are interconnected by another curved segment 34c. Instead of the two linear segments 34b, the separating wall 32 according to FIG. 5b comprises two curved segments 34a being interconnected with another curved segment 34c. The separating wall 32 according to FIG. 5c does not comprise thickened segments 35. The thickened segments 35 are respectively replaced by two linear segments 34b which together with the mixer housing 12 and the output surface 30 of the mixing head 22 enclose a volume 31 being not accessible for the components leaving the outlets 28a, 28b.

[0070] FIG. 6 is identical to the cross-sectional view of FIG. 4b and indicates in addition the flow paths of the components. To provide a better overview most of the reference numerals have been omitted. In operation of the static mixer 10 a first component A is fed from a cartridge into the inlet 24a and a second component B is fed from the cartridge into the inlet 24b. Both components A, B proceed through the mixing head 22 until reaching the outlets 28a, 28b on the output surface 30. Each component A, B leaves the respective outlet 28a, 28b and starts to occupy the volume defined by the separating wall 32, the output surface 30 and the mixer housing 12. Thereby the flow obstructions 40a, 40b prevent the components A, B from premature proceeding beyond the downstream edge 33 of the separating wall 32 and from directly entering the entry openings 20a, 20b, 20c. The flow obstructions 40a, 40b are dimensioned such that the entry openings 20a, 20b, 20c are simultaneously and uniformly supplied by the components. An undue forerunning of either of the components is prevented.

[0071] Due to the meandering pattern of the separating wall 32 the components A, B when reaching the downstream edge 33 are arranged side by side in three partial flows or streaks in a plane perpendicular to the longitudinal axis A.sub.L. These three partial flows are indicated by arrows A1, B1, B2, wherein A1 corresponds to component A and B1, B2 correspond to component B. The partial flow A1 of component A is flanked by two partial flows B1, B2 of component B. After exceeding the downstream edge 33 of the separating wall 32 the three partial flows A1, B1, B2 combine (without becoming intermixed) and are transversely divided by the intermediate wall 36 such that six partial flows A1.sub.1, A1.sub.2, B1.sub.1, B1.sub.2, B2.sub.1, B2.sub.2 result which are indicated by six arrows pointing upwards out of the drawing's plane. A1.sub.1, A1.sub.2 represent the divided partial flow A1 of component A. B1.sub.1, B1.sub.2, B2.sub.1, B2.sub.2 represent the respectively divided partial flows B1 and B2 of component B. Three partial flows, i.e. A1.sub.1, flanked by B1.sub.2 and B2.sub.2, are located on side 38a and three partial flows, i.e. A1.sub.2 flanked by B1.sub.1 and B2.sub.1, are located on side 38b of the intermediate wall 36.

[0072] As regards side 38a of the intermediate wall 36, when proceeding further the partial flow A1.sub.1 encounters the bottom edge 51 of the bottom section 50 of the first mixer element 42 (see FIG. 2). The bottom edge 51 splits A1.sub.1 into two parts which are respectively forced sideways to jointly enter the openings 20a, 20b together with one of the two outer partial flows B1.sub.2 and B2.sub.2, respectively. Thus, the entry opening 20a is fed with a partial flow consisting of A1.sub.1 and B1.sub.2 and the entry opening 20b is fed with a partial flow consisting of A1.sub.1 and B2.sub.2. This distribution is indicated by FIG. 7 showing a simplified cross-sectional view along the entry plane of entry openings 20a, 20b, 20c.

[0073] As regards the other side 38b of the intermediate wall 36, when proceeding further each of the two outer partial flows B1.sub.1 and B2.sub.1 encounter one of the lateral sections 52a, 52b (see FIG. 2). Thereby the partial flows B1.sub.1, B2.sub.1 are forced sideways towards partial flow A1.sub.2 which encounters the opening 20c. Thus, the opening 20c is fed with a partial flow consisting of A1.sub.2 flanked by B1.sub.1 and B2.sub.1 as indicated by FIG. 7.

[0074] Thus, each opening 20a, 20b, 20c of the first mixer element 42 is fed with partial flows of both components A, B. Altogether, this results in seven alternating partial flows being fed into the entry openings 20a, 20b, 20c. The partial flows are split as follows among the openings 20a, 20b, 20c starting from opening 20a: B1.sub.2, A1.sub.1, B1.sub.1, A1.sub.2, B2.sub.1, A1.sub.1, B2.sub.2. This leads to a high mixing level already emerging after the first mixer element 42 has been passed. Thereby the total number of successive mixer elements 42 can be kept small and the total length of the static mixer can thus be reduced.

LIST OF REFERENCE NUMERALS

[0075] 10 static mixer [0076] 11 wider housing section [0077] 12 mixer housing [0078] 13 shoulder [0079] 14 mixing element [0080] 15 narrow housing section [0081] 16 upstream end [0082] 18 downstream end [0083] 20a, 20b, 20c entry opening [0084] 22 mixing head [0085] 24a, 24b inlets [0086] 26 input side [0087] 28a, 28b outlets [0088] 30 output surface [0089] 31 volume [0090] 32 separating wall [0091] 33 downstream edge [0092] 34a, 34c curved segment [0093] 34b linear segment [0094] 35 thickened segment [0095] 36 intermediate wall [0096] 38a, 38b sides defined by intermediate wall [0097] 40a, 40b flow obstruction [0098] 41 rim [0099] 42 mixer element [0100] 44 transverse edge [0101] 45 transverse guide wall [0102] 46a, 46b guide walls [0103] 48 separating edge [0104] 49a, 49b sloping part [0105] 50 bottom section [0106] 51 bottom edge [0107] 52a, 52b lateral end section [0108] 54a, 54b sides of transverse edge [0109] 56 strut [0110] A.sub.L longitudinal axis [0111] A1, A1.sub.1, A1.sub.2 partial flows of component A [0112] B1, B2, B1.sub.1, B1.sub.2, B2.sub.1, B2.sub.2 partial flows of component B