DE102008020827A1 - Mixer, method of making such and mixer assembly - Google Patents

Abstract

The present invention relates to a static mixer (10; 20; 30; 40; 50; 60; 70) for mixing at least one fluid stream across a flow area in a pipe section (101). The mixer (10; 20; 30; 40; 50; 60; 70) has a plurality of webs (13; 23; 33; 43; 53; 63; 73) extending transversely to the flow direction and extending from these webs to the flow direction (B ) inclined guide elements (14; 24; 34; 44; 54; 64; 74b). The webs (13; 43; 53; 63; 73) pass through the flow cross-section without touching each other, and the guide elements (14; 24; 34; 44; 54; 64; 74b) and webs (13; 43; 53; 63 ; 73) are integrally connected. The invention further relates to a method for producing such a mixer and to a mixing arrangement (100) having at least two mixers (10; 20; 30; 40; 50; 60; 70) according to the invention.

Description

The The present invention relates to a mixer for mixing at least a fluid flow in a pipe section. The invention further relates a mixer arrangement comprising at least two such mixers, which are arranged one behind the other in a pipe section and a method for producing such a mixer.

static Mixers are used to one or more in a pipe section fluidizing fluid streams or with each other to mix.

Of the Fluid flow used here is also meant to include such flows include, for example, small droplets or Particles are transported in a fluid stream.

static Mixers are z. B. used in the emission control. It will in an exhaust stream flowing in a pipe section (for example, from an internal combustion engine), via a probe injected a reagent (for example, urea for NOX reduction). Subsequently, the exhaust stream and reactants are a Catalyst supplied in which the desired reaction takes place for the exhaust gas treatment. So as complete as possible and uniform reaction throughout the exhaust stream takes place, the exhaust stream and reactant stream before Entry into the catalyst as completely as possible mixed together. Only then can the reagent be dosed correctly added and the catalyst surfaces optimally be used for the reaction. The static mixer (s) should be doing on a shortest possible flow path Exhaust gas stream and reactant stream largely homogeneous with each other mix while maintaining the lowest possible flow resistance build up. In addition, just play in the automotive sector Costs and thus production engineering aspects a big one Role; that is, the static mixer should as possible be inexpensive to produce.

At one of the DE 10 2006 024 778 B3 known static mixer a plurality of transverse to the flow direction layers of a wave-shaped strip material are provided, which forms a plurality of flow-through cells, wherein on the downstream side (outlet side of the flow) of the cells curved flow control surfaces are provided which extend in the flow direction and transverse thereto and thus the mixing and fluidizing fluid streams passed through the cells.

A similar static mixer is in 11 shown. Here lattice-shaped crossed, durchströmbare cells forming laminations are provided, which are provided on the downstream side tongue-shaped, planar flow guide, mix the fluid streams passing through the grid cells with each other and swirl. The grid-like arranged lamellae are fixed in a tubular support section.

Both Designs provide effective and fluidic sophisticated static mixers. However, they require a relative high production costs and are therefore expensive.

From the DE 197 41 199 A1 a simple constructed, static mixer is known in which a so-called. Expanded mesh is arranged in the pipe cross-section of a flow channel and a flow around the lattice struts and nodes generates the mixing of fluid flows causing vortex and turbulence. For improved mixing, such a grid can also be arranged inclined to the direction of flow. It is also envisaged to arrange several such gratings one behind the other. However, this may be disadvantageous in terms of flow, since under certain circumstances a high pressure drop in the flow may occur when passing through the expanded metal grid arrangement. Thus, if necessary, the flow characteristics, which should be precisely matched, in particular in the exhaust system of a motor vehicle, are disturbed too much.

From the DE 43 13 393 A1 a static mixer arrangement is known in which in each case a plurality of trapezoidal deflection elements are arranged in transverse to the flow direction rows. The deflection elements are inclined in each row parallel to each other in the flow direction. In each case adjacent rows are provided in pairs, the deflection elements are offset from one another in the longitudinal direction and inclined in opposite directions. The rows carrying the deflecting elements are in each case brought into contact with each other back to back and installed in pairs in a carrier grid. In this case, a plurality of rows of deflection elements and carrier grid elements are joined together to form a static mixer.

From the DE 35 36 315 A1 a so-called swirl body is known in which from a standing perpendicular to the flow direction base plate vanes are partially punched out and bent, which project helically in the flow direction and imparting in the resulting openings exhaust gases in addition to their flow direction, a rotation pulse (twist). However, such spin bodies are suitable only to a limited extent for mixing two gas streams / fluid streams. The possibly desired cyclone effect for the separation of solid particles located in the fluid stream causes only a comparatively small vermi tion of the fluid flow.

A similar arrangement is from the WO 03/036056 A1 known to produce in the opposite direction oriented baffles two concentric flows with opposing swirl and thus cause a mixing of several fluid streams. Although the two last-mentioned embodiments can be produced in a cost-effective stamping process. However, there are fluidic restrictions, since here - in relation to the guide surfaces - relatively large transverse to the flow direction of the disturbance surfaces, the pressure drop between the inflow and outflow can be significant.

The Object of the present invention is to provide an improved to provide static mixer. It is particularly desirable good mixing properties, favorable flow conditions and a constructive or manufacturing technology favorable Combine design with each other.

These Task meets the mixer with the features of the claim 1, a mixing arrangement according to claim 12 and a method for producing the mixer according to claim 13th

Of the inventive mixer has transverse to the flow direction extending webs, of which to the flow direction go out inclined guide elements. The webs enforce the Flow cross-section without touching each other, and the vanes and lands are integral with each other connected. Such a mixer allows a simple structure with comparatively favorable flow properties and to combine a good mixing characteristic.

So a mixer carries the diverging demands after slight pressure loss when flowing through the mixer, an effective mixing of a fluid stream on a short Track and a production technology favorable and therefore cost-effective Design together.

The Features of claims 2 to 8 relate to manufacturing technology and functionally advantageous solutions.

To Claim 2, the guide elements are each along a crease line coupled with the dock. Thus, the areas are web and guide element functionally separate from each other; the webs form the supporting structure and the guiding elements the actual mixing structure. You can but still prefabricated together from one piece (z. Punched out). The processing is comparatively simple Punching and embossing tools possible. The pre-punched Guide elements can from the web along the respective Kantlinie be folded and employed with different inclinations in the fluid flow become.

To Claim 3 are each provided a plurality of guide elements side by side, so that several tongue-like guide elements can be lashed for mixing or spoon-shaped provided on the webs which can be independently along their respective Kantlinie are deformable to the bridge. So are different designed vanes with different inclinations 15 ° to 45 ° at different locations in the flow cross-section feasible. The mixer can thus also to a certain flow inlet profile be adjusted. The mixing properties are over the flow cross section variable. Are the Kantlinien offset parallel to each other, as stated in claim 4, it may this effect can be further improved.

According to claim 5 can be for a very simple and easy to manufacture Execution the guide elements also lamellar along the total length of a bridge be formed. This can be done further simplify the required manufacturing steps and tools.

By a convex or concave shape of the guide elements with respect the flow direction according to claim 6 can additionally positive flow effects be achieved, which reduce the flow resistance and / or improve the mixing properties.

According to claim 7, the formations are arranged over appropriately Cantlines provided. This design allows a repeatable production with comparatively simple tools.

The in claim 8 specified ratio between the web width and the web strength is in view of the particularly cost-effective stamping-embossing production advantageous and offers a high structural stability.

By according to claim 9 connecting the webs with each other Border area is a stable mixer representable, as a complete, in one piece producible, disc-shaped component can be used in predetermined pipe cross sections.

The webs and the edge region define an end face pointing in the flow direction, and turbulence surfaces inclined to the flow direction are provided on the guide elements. According to claim 10, the end face and the sum of the inclined swirling surfaces form a ratio of 0.8 to 0.35 and preferably a ratio of 0.5 to 0.4. The face and swirl surfaces cover a range of 50% to 75% of the flow cross-section.

The Embodiment according to claim 11 also allows a manufacturing technology particularly favorable press-stamping-punching component, which additionally stabilizes over the sidewall area becomes. It can simply be inserted into a corresponding piece of pipe, without it tilting when inserting.

The Mixer arrangement according to claim 12, the mixing quality increase significantly, so the mixed length, the means the required length of the pipe section, in which the fluid streams are to mix, shortened becomes. The intended mixers can do this differently be formed. But it is also possible through a different arrangement of identical mixer to each other the desired Improve mixing results. This can be done by the individual Mixer inclined to the flow direction and / or in the circumferential direction to each other be arranged twisted.

The Process according to claims 13 to 15 concern particularly favorable and cost-saving manufacturing processes for a mixer according to the invention.

embodiments The present invention will be described below with reference to the drawings explained. It shows

1 A first embodiment of a mixer according to the invention in a perspective view,

2 the mixer off 1 in a side view,

3 a view towards B of in 1 and 2 shown mixer,

4 A second embodiment of a mixer according to the invention in a perspective view,

5 A third embodiment of a mixer according to the invention in a perspective view,

6 A fourth embodiment of a mixer according to the invention in a perspective view,

7 A fifth embodiment of a mixer according to the invention in a perspective view,

8th A sixth embodiment of a mixer according to the invention in a perspective view,

9 a sectional view of a mixer arrangement with two mutually rotated mixers according to 7 .

10 a flow chart of a manufacturing method according to the invention,

11 a known from the prior art mixer, and

12 a seventh embodiment of a mixer according to the invention in a perspective view.

A first embodiment of a mixer according to the invention 10 is in the 1 to 3 shown. The mixer 10 is manufactured in a deep-drawing punching embossing process and has a cup-like shape. The mixer 10 has a floor area 11 and a sidewall area 12 on. In the ground area 11 run side by side, contactless multiple webs 13 , on which tab-like guiding elements 14 are formed.

These guide elements are inclined at an angle of 15 ° to 45 ° to the flow direction B, parallel to the in 2 illustrated central axis 15 runs. The guiding elements 14 stand each alternately and in the longitudinal direction of the webs 13 offset from each other in different directions from the webs 13 from. They are along the crease lines 16 connected to the webs. Seen in the longitudinal direction of the webs ( 2 ) are the ends of the vanes 14 arranged interleaved. In the illustrated embodiment, the guide elements 14 a tapered to the free ends trapezoidal shape, wherein the transition areas between the lateral edges of the guide elements 14 and the end edge are rounded.

The bridges 13 themselves are in the ground area 11 over a border area 17 connected to each other, which rounded in the pipe section formed as a side wall area 12 passes.

The mixer 10 is preferably in the direction B ( 2 ) flows through the one or more fluid streams or streams to be mixed together. Here is the facing in the direction of flow B end face 18 , which are made up of the corresponding area proportions of the edge area 17 , the bridge 13 as well as the extensions 13a composed, in relation to the also pointing in the flow direction Verwirbelungsflächen 19 at the guide elements 14 from 0.8 to 0.35 and preferably in a ratio of 0.5 to 0.4. As Verwirbelungsfläche apply in the Ground plane projected surfaces of the guide elements 14 ,

Bridge width b and the bridge thickness S or the material thickness of the mixer are in a ratio of 2: 1 to 1: 1. In these proportions, the guide elements can be 14 clean along the ruled lines 16 from the jetties 13 edge without being bent out of their planar arrangement.

At the mixer 10 are the creases 16 and the corresponding web portions parallel to each other and transversely offset to the web course. In this way, at the folded guide elements 14 reaches the desired Verschränkungsmaß, which improves the turbulence of the passing flow.

There are also versions where the creases 16 not parallel, but at an angle to each other.

The mixer 10 is preferably made of a thermoformable sheet metal material. When used in a vehicle exhaust system are particularly austenitic steel materials, eg. B. in qualities such as 1.4301 o. Ä., Suitable in output wall thicknesses of 0.75 to 3 mm. The diameter of the illustrated mixer is typically 50 to 75 mm.

4 and 5 show variants 20 and 30 in the 1 to 3 shown mixer 10 ,

The mixer 20 according to 4 has slightly modified vanes 24 on, which are arched so that the concave side with the Verwirbelungsfläche 29 points in the direction of flow and the curvature around a transverse to the creases 16 from the approach area of the guide elements 24 until its end running bending line 25 runs.

The in 5 illustrated mixer 30 also has curved guide elements 34 on where the camber around the bend line 25 he follows. However, it is executed in the other direction, so here is the convex side with the swirling surface 39 points in the flow direction. In addition to the in 4 and 5 illustrated one-dimensional curvature of the Leit elements 24 and 34 can also be provided a two-dimensional curvature or curvature of the guide elements, in which they are then formed more or less spoon-shaped.

In other embodiments, not shown, both the shape and size, as well as the inclination, as well as the curvature of individual vanes 14 . 24 or 34 be individually formed differently. As a result, the mixing properties can be individually matched to a stationary inflow profile and optimized.

12 shows a mixer 70 whose bottom area 71 is divided into two parts. The edge floor area 71a includes a wreath with outer vanes 74a , These are aligned in the circumferential direction and so along radially extending canted lines 76a issued that they give a swirling pulse when flowing through the outer edge region of the flow. The central floor area 71b has transverse webs 73 on, on which the guiding elements 74b are designed and arranged similar to those associated with the 1 . 3 and 4 described guiding elements 14 . 24 and 34 ,

In a further embodiment, not shown, the outer guide elements 74a also in pairs of a common Kantlinie 76 starting to be issued against each other, so that in the edge bottom area 71a then no swirl effect arises.

In other embodiments, not shown, the central floor area 71b also be designed as in connection with the embodiments according to the 6 . 7 and 8th will be described below.

6 shows an embodiment of a mixer 40 in which the guiding elements 44 lamellar along the footage of the footbridges 43 are formed. Also these guiding elements 44 are arched along a bend line 45 parallel to the canted line 46 runs. The ends of the guide elements are 44 coming from neighboring jetties 43 go out, facing each other.

7 shows a similar mixer 50 in which the guiding elements 54 but without additional curvature than straight flaps along the cane lines 56 are arranged along the ridges 53 run.

When in 8th shown mixer 60 is at every jetty 63 only a single lamellar guide element 64 intended. The guiding elements 64 Here all are oriented in the same direction and along the lines 66 exhibited from the soil area level.

9 shows a mixer arrangement 100 in which two mixers 50 in a pipe section 101 are arranged. The two mixers 50 Here are 90 degrees to each other used twisted and one behind the other along the flow axis 15 arranged. The distance of the mixers 50 each other can be chosen so that an optimal mixing result occurs. The sidewall area 52 allows the clean insertion of the mixer 50 in the pipe section 101 without passing through the floor areas 51 tilted defined cross-sectional planes (mixing levels).

In other mixer arrangements, not shown, different mixers can be combined. It is also possible, in addition to the mutually twisted arrangement, the mixer 10 . 20 . 30 . 40 . 50 . 60 with extending in different inclined planes floor areas - so obliquely - in a pipe section 101 to arrange.

It also continues to be versions where the mixers are formed without side wall area. Such mixers are then more or less disc-shaped, where only the edge area connects the webs with each other. Such a disc-shaped Mixer can then for example also placed on a pipe end be inserted or between two pipe ends. It is also possible, such a disc-shaped mixer insert into a corresponding receiving slot of a pipe section.

10 shows the sequence of a method for producing the mixer 10 , For this purpose, first of all a suitable semi-finished product is provided, which in the present case is a flat sheet metal material which is provided as a single piece of sheet metal or as a continuous sheet metal strip (coil material). Then the outer contour is cut out. This can happen mechanically, thermally or abrasive depending on the material used. Suitable working processes are, for example, stamping, plasma cutting or water jet cutting.

The cup form is produced in a drawing or deep-drawing process, in which the semifinished product is plastically deformed using a die and a male part, so that it comes close to the desired final shape after the molding process. In a second postforming process, the geometry is further approximated. For example, the transition radii become between the sidewall area 12 and the floor area 11 at the edge 17 reduced.

Next are the contours of the webs 13 and the guiding elements 14 Are defined. A two-step punching process ensures that there are no undesirable plastic deformations of the webs 13 or the guide elements 14 respectively. The two-stage punching has the further advantage that the tool geometries are simplified for possibly required punching tools and the relatively complex web-Leitelementkontur clean and repeatable to produce.

In the last, the actual Mixer geometry determining step become the guiding elements 14 tilted along the ridge lines and relative to the ridges 13 deformed.

In addition, in a possibly required finishing the individual mixer 10 be separated from a guide strip required for processing. Possibly. Work can also be done on deburring or calibrating the finished parts. In a final surface treatment, for example, a corrosion protection can be applied.

If necessary, the individual work steps can be supplemented by further steps, for example in the case in which the guide elements as in the 4 . 5 and 6 shown additionally deformed. There are also cases where steps are omitted, for example, when the mixer disc-shaped, that is without the sidewall area 12 be executed. In this case, the steps "drag" and "reshape" are eliminated. For simple geometries of the guide elements (see. 6 . 7 . 8th ), the punching can also be carried out in one stage or together with the "tilting".

Further Variations and variations of the present invention result for the skilled person within the scope of the following claims.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 102006024778 B3 [0005]
• - DE 19741199 A1 [0008]
• - DE 4313393 A1 [0009]
• - DE 3536315 A1 [0010]
• WO 03/036056 A1 [0011]

Claims (15)

Static mixer ( 10 ; 20 ; 30 ; 40 ; 50 ; 60 ; 70 ) for mixing at least one fluid flow over a flow cross section in a pipe section ( 101 ), with transverse to the flow direction webs ( 13 ; 43 ; 53 ; 63 ; 73 ) and from these webs outgoing inclined to the flow direction guide elements ( 14 ; 24 ; 34 ; 44 ; 54 ; 64 ; 74b ), whereby the webs ( 13 ; 43 ; 53 ; 63 ; 73 ) pass through the flow cross-section without touching each other, and the guide elements ( 14 ; 24 ; 34 ; 44 ; 54 ; 64 ; 74b ) and bridges ( 13 ; 43 ; 53 ; 63 ; 73 ) are integrally connected. Mixer ( 10 ; 20 ; 30 ; 40 ; 50 ; 60 ; 70 ) according to one of the preceding claims, in which the guide elements ( 14 ; 24 ; 34 ; 44 ; 54 ; 64 ; 74b ) each along a crease line ( 16 ; 46 ; 56 ; 66 ) with a bridge ( 13 ; 43 ; 53 ; 63 ; 73 ) are connected. Mixer ( 10 ; 20 ; 30 ; 40 ; 50 ; 70 ) according to one of claims 1 and 2, wherein in each case a plurality of guide elements ( 14 ; 24 ; 34 ; 44 ; 54 ) along different edge lines ( 16 ; 46 ; 56 ) with a bridge ( 13 ; 43 ; 53 ; 73 ) are connected. Mixer ( 10 ; 20 ; 30 ; 70 ) according to claim 3, in which the canted lines ( 16 ) in sections offset parallel to each other. Mixer ( 40 ; 50 ; 60 ; 70 ) according to one of claims 1, 2 or 3, in which the guide elements ( 44 ; 54 ; 64 ) each lamellar along the total length of a web ( 43 ; 53 ; 63 ; 73 ) are formed. Mixer ( 20 ; 30 ; 40 ; 70 ) according to one of the preceding claims, in which the guide elements ( 24 ; 34 ; 44 ; 74b ), with respect to the flow direction (B) have a convex and / or concave shape. Mixer ( 20 ; 30 ; 40 ; 70 ) according to claim 6, wherein the molding along at least one further edge line ( 25 ; 45 ) is formed on the guide element. Mixer ( 10 ; 20 ; 30 ; 40 ; 50 ; 60 ; 70 ) according to one of Claims 1 to 7, in which the web width (b) in the disk plane and the web thickness (S) perpendicular to the disk plane are in a ratio of 2: 1 to 1: 1. Mixer ( 10 ; 20 ; 30 ; 40 ; 50 ; 60 ; 70 ) according to one of claims 1 to 8, in which the webs ( 13 ; 23 ; 33 ; 43 ; 53 ; 63 ; 73 ) at their ends in one piece with an edge region interconnecting the webs ( 17 ) are formed. Mixer ( 10 ; 20 ; 30 ; 40 ; 50 ; 60 ; 70 ) according to one of claims 1 to 9, in which the webs ( 13 ; 43 ; 53 ; 63 ; 73 ) and the border area ( 17 ) a flow direction facing end face ( 18 ) and the guiding elements ( 14 ; 24 ; 34 ; 44 ; 54 ; 64 ; 74a ; 74b ) an inclined to the flow direction (B) Verwirbelungsfläche ( 19 ; 29 ; 39 ), the end face ( 18 ) to the swirl surface ( 19 ; 29 ; 39 ) in a ratio of 0.8 to 0.35 and preferably in a ratio of 0.5 to 0.4 and frontal and Verwirbungsfläche ( 18 . 19 ; 29 ; 39 ) together cover 50% to 75% of the flow cross-section. Mixer ( 10 ; 20 ; 30 ; 40 ; 50 ; 60 ; 70 ) according to one of claims 1 to 10, which is in one piece, cup-shaped with a bottom region ( 11 ) and a sidewall region extending in the direction of flow ( 12 ) is formed, wherein the webs ( 13 ; 43 ; 53 ; 63 ; 73 ), the edge area ( 17 ) and the guiding elements ( 14 ; 24 ; 34 ; 44 ; 54 ; 64 ; 74a ; 74b ) from the soil area ( 11 ) are formed. Mixing arrangement ( 100 ) with at least two mixers ( 10 ; 20 ; 30 ; 40 ; 50 ; 60 ; 70 ) according to one of the preceding claims, which in the flow direction in a row in a pipe section ( 101 ) are arranged, wherein the mixers are each formed differently and / or different from each other. Method for producing a mixer ( 10 ; 20 ; 30 ; 40 ; 50 ; 60 ; 70 ) according to one of claims 1 to 11, comprising: - providing a sheet material - punching out an outer contour defining the mixer shape - first punching out a web and guiding elements defining inner contour - shaping the guide elements along the webs extending canted lines The method of claim 13 additionally comprising: - Forming a sidewall region in a deep drawing process. A method according to claim 13 or 14 additionally comprising: - convex and / or concave shaping of the guide elements to the flow direction along at least one bending line ( 25 ; 45 ).