EP0776689B1 - Mixing device - Google Patents

Description

Technical field

The invention relates to a mixing device for mixing two or more fluids that are the same or different May have mass flow, the to be mixed Fluids flow along a partition, on the downstream End of several vortex generators with free flow areas are arranged, several of them side by side are arranged, the side faces of the vortex generator are flush with one side of the partition and with each other include the arrow angle, the longitudinal ones Edges of the side surfaces at an angle to the wall run and the two side surfaces a connecting edge include each other, preferably perpendicular to the wall runs and the edge first hit by the flow is.

State of the art

Such mixing devices are known for example from EP-A1-0 619 134. In many sectors such as in Chemistry that becomes food or pharmaceutical production etc. requires to mix fluids intimately by the shortest route. The Quality of the whole process mostly depends on the achieved Mixed quality. The pressure drop should be considered of the mixing process remain in a "reasonable" framework in order to Keep process costs low thanks to low pumping work.

In the above-mentioned document EP 0619 134 A1 is a generic Mixing chamber described, the one, having several vortex generators Separating plate provides. A vortex generator has three free-flowing surfaces, one roof surface and two side surfaces, the roof surface runs under one Angle of attack to the partition plate, the two side surfaces close together Arrow angle on. The vortex generator is used to generate from a material flow Flow around longitudinal vortices. A vortex generator of almost the same structure goes out of the EP 0 620 403 A1.

The vortex generators described in the two publications cited above each have a trailing edge that runs in a straight line on, i.e. the edge over which the roof surface is connected to the partition.

Presentation of the invention

The invention has for its object in a mixing device to improve the mixing of the type mentioned.

• dass eine Dachfläche aus zwei Teildachflächen besteht, wobei die längsgerichteten Kanten der Teildachflächen bündig sind mit den Kanten der Seitenflächen und die Teildachflächen über eine Verbindungskante miteinander verbunden sind,
• dass die stromabwärts liegenden Hinterkanten der Teildachflächen mit der Trennwand einen Winkel einschliessen, wodurch die Hinterkanten in Bezug auf die Seitenflächen im wesentlichen auf die andere Seite der Trennwand zu liegen kommen,
• und dass eine Bodenfläche aus zwei Teilbodenflächen besteht, die über eine Verbindungskante miteinander und über die Hinterkanten mit den Teildachflächen verbunden sind.

According to the invention, this is achieved by

• that a roof surface consists of two partial roof surfaces, the longitudinal edges of the partial roof surfaces being flush with the edges of the side surfaces and the partial roof surfaces being connected to one another via a connecting edge,
• that the downstream rear edges of the partial roof surfaces form an angle with the partition wall, as a result of which the rear edges come to lie essentially on the other side of the partition wall with respect to the side surfaces,
• and that a floor area consists of two partial floor areas which are connected to one another via a connecting edge and to the partial roof areas via the rear edges.

The advantages of the invention include that by introducing the twisted towards the partition Trailing edges the downstream edge of the partition is extended. As a result, the contact area of the streams to be mixed are increased; further eddies created by the trailing edges. These vertebrae support and strengthen those of the longitudinal edges generated vortices of the vortex generator. In addition, the mixing of the streams to be mixed increased because the vertebrae are facing each other Propagate electricity, creating an interwoven flow pattern arises.

From the fluidic point of view, the vortex generator element a very low pressure drop when flowing around on and it creates vortices with no dead water area. Finally can the element through its usually hollow interior cooled in various ways and with various means become.

It is particularly useful if the two use the arrow angle α enclosing side surfaces and the partial roof surfaces the vortex generator symmetrical to a plane of symmetry, formed by an axis of symmetry and the connecting edge the side surfaces are arranged. This makes them twisty Vortex generated.

Brief description of the drawing

In the drawings is an embodiment of the invention shown schematically.

Fig. 1

eine perspektivische Darstellung eines Wirbelgenerators, Sicht von oben;

Fig. 2

eine perspektivische Darstellung des Wirbelgenerators, Sicht von unten;

Fig. 3

eine perspektivische Darstellung mehrerer Wirbelgeneratoren;

Fig. 4

Draufsicht auf die Wirbelgeneratoren von Fig.3;

Fig. 5

Teilquerschnitt durch einen Kanal mit darin angeordneten Wirbelgeneratoren.

Show it:

Fig. 1

a perspective view of a vortex generator, view from above;

Fig. 2

a perspective view of the vortex generator, view from below;

Fig. 3

a perspective view of several vortex generators;

Fig. 4

Top view of the vortex generators of Figure 3;

Fig. 5

Partial cross section through a channel with vortex generators arranged in it.

It is only essential for understanding the invention Elements shown.

Way of carrying out the invention

1 there is a vortex generator 9 essentially from several freely flowing triangular surfaces. There are this is two partial roof surfaces 1, 2, two side surfaces 11, 13 and two partial floor areas not visible in FIG. 1. In These surfaces run under certain longitudinal directions Angles in the direction of flow.

The two side surfaces 11 and 13 are each perpendicular on the associated top 21 of a partition 22, wherein it is noted that this is not mandatory. The side faces 11, 13, which consist of right-angled triangles, are fixed here with their longer cathete on the partition 22. They are so oriented that they are shorter with theirs The catheter forms a joint, including an arrow angle α. The joint is designed as a sharp connecting edge 16 and is also perpendicular to the partition 22. In one Channel installed because of the sharp connection edge the flow cross-section hardly affected by blocking. Due to the longer cathets of the side surfaces 11, 13 and an intersection point 8 is formed by the connecting edge 16, which is in the partition. The two the arrow angle α enclosing side surfaces 11, 13 are symmetrical in Shape, size and orientation and are on both sides of a plane of symmetry arranged by an axis of symmetry 17th and the connecting edge 16 is formed. The axis of symmetry 17 is usually the same direction as the channel axis and so like the channel flow.

An essentially longitudinal edge 12 of the partial roof surface 1 is flush with the hypotenuse of the side surface 11 protruding into the flow channel. This longitudinal edge 12 runs at an angle of inclination  to the wall 22. A downstream rear edge 5 of the partial roof surface 1 lies in a plane perpendicular to Axis of symmetry 17 and is rotated by an angle γ with respect to the partition wall 22, so that the rear edge 5 comes to lie below the partition wall. To assemble the vortex generator 9, slots must therefore be made in the partition 22, or the partition must be adapted accordingly.
The partial roof surface 2 is symmetrical to the partial roof surface with respect to the plane of symmetry, formed by the axis of symmetry 17 and the connecting edge 16. Thus, a longitudinal edge 14 of the partial roof surface 2 is flush with the hypothenus of the side surface 13 protruding into the flow channel Angle of attack  to the wall 22. A rear edge 6 of the partial roof surface 2 also lies in the plane perpendicular to the axis of symmetry 17 and is rotated by the negative angle γ with respect to the partition wall, so that the rear edge 6 comes to lie below the partition wall 22. The second longitudinal edge of the partial roof surface 1 forms with the second longitudinal edge of the partial roof surface 2 a connecting edge 10 which lies in the plane of symmetry formed by the axis of symmetry 17 and the connecting edge 16. The connecting edge 10 forms with the trailing edge 5 and with the trailing edge 6 a tip 7 located at the downstream end of the vortex generator 9. The longitudinal edges 12, 14 together with the connecting edge 16 and the connecting edge 10 form a tip 18 located at the upstream end of the vortex generator 9.

2, the triangular partial floor surface 3 is defined through the trailing edge 5 and the intersection 8, the triangular Partial floor surfaces 4 are defined by the rear edge 6 and the intersection point 8. A connecting edge 30 of the partial bottom surfaces 3, 4 thus extends from the top 7 to to intersection 8.

Of course, the vortex generator can also be used without floor surfaces are produced, then the partition Function of the floor areas takes over. This requires the partition be serrated at its downstream end, accordingly the partial floor areas. To the contact area on can further increase the downstream end of the partition the trailing edges of the vortex generator also in different Layers that are not perpendicular to the axis of symmetry.

3 and 4, a vortex generator 9 'is on the underside 20 of the partition 22 and a vortex generator 9 the top 21 of the partition arranged side by side. The Vortex generator 9 'is identical in shape and size to that Vortex generator 9, the names already used above for the vortex generator 9 are therefore also for the vortex generator 9 'used, but are provided with an apostrophe. The vortex generator 9 can be rotated by 180 ° can be transferred to the vortex generator 9 'about an axis of rotation 19. The axis of rotation 19 lies in the partition 22, is parallel to the axis of symmetry 17 and goes through the intersection of Long edge 14 and trailing edge 6.

The connecting edge 16 of the two side surfaces 11, 13 forms always the upstream edge of the vortex generators 9, 9 '. The sharp connecting edge 16 is the point that of the channel flow is applied first. The flow across Partition 22 trailing edges 5, 6, 5 ', 6' the roof areas are the last from the channel flow loaded edges.

Of course, the vortex generators 9 'can also be different are designed as the vortex generators 9, wherein the vortex generators always have one of the basic configurations shown have similar geometry. For example, this is advantageous for mixing physically different flows.

The vortex generator works as follows: Flowing around edges 12 and 14, the flow becomes a pair opposite vortex converted. The vortex axes are in the axis of the flow. The geometry of the vortex generators is selected so that there are no backflow zones during vortex generation arise. The vortices of the vortex generator 9 rotate along the roof surfaces and strive for the partition 22 to which the vortex generator is mounted. The vertebrae of the vortex generator 9 'rotate below the roof surfaces along and also strive towards the partition 22.

The swirl number of the vertebra is determined by appropriate Choice of the angle of attack  and / or the arrow angle α. With increasing angles become the vortex strength or the swirl number increased and the place of vortex breakdown (vortex break down) - if this is desired at all - migrates upstream down to the area of the vortex generator itself. Depending on Application are these two angles  and α by constructive Conditions and determined by the process itself. customized then only the height h of the connecting edge needs to be 16. By choosing the angle γ the vertebrae become like this influences that the larger γ is selected, the better the Mixing of the partial flows takes place. However, the angle γ can not be chosen arbitrarily large, because with increasing γ the pressure drop also increases.

It should be noted that the shape of the flow Partition 22 is not essential to the operation of the invention is. Instead of the straight form shown in the figures the partition 22 could also be an annular or act hexagonal or other cross-sectional shape. At a curved partition, the above statement that the Side surfaces are perpendicular to the wall, of course can be put into perspective. The decisive factor is that on the Line of symmetry 17 lying connection edge 16 perpendicular the corresponding wall. In the case of annular walls the connecting edge 16 would thus be aligned radially his.

Fig. 5 shows partially a channel with a built-in partition 22. The cross section through which flow is through this partition 22 divided into two subchannels with channel heights H1 and H2. The top 21 of the partition wall 22 forms a channel wall of the upper channel 41, the underside 20 of the partition 22 forms a channel wall of the lower channel 42. The two Channels could be from the same medium with different ones Flow through speed; or it could be flowing fluids of different density or chemical composition act the shortest way to a specific one evenly distributed concentration can be mixed have to.

On the two channel walls 20 and 21 of the partition is in each case an equal number of vortex generators 9, 9 'with gaps strung together. The height h1 of the elements 9 as well The height h2 of the elements 9 'is, for example, approx. 90% of the associated duct heights H1 and H2. The flow takes place 5 perpendicularly out of the plane of the drawing; the Elements 9, 9 'are oriented so that the connecting edges 16 are directed against the current. The direction of rotation of the generated Vortex in the area of the connecting edge is descending, i.e. it strives towards the respective channel wall 20, 21 which the vortex generator is arranged. At the end of the partition 22, i.e. at the rear edges 5, 6, 5 ', 6', the eddy currents generated on their two sides, which leads to the desired mixing.

Combine the swirl-like vortices in the sub-channels 41, 42 become a large vortex with a uniform sense of rotation. The axis of rotation of this large vortex is essentially that Axis of rotation 19.

The vortex generators 9, 9 'can be different in the channels 41, 42 Heights h1, h2 compared to the channel heights H1, H2 exhibit. As a rule, the heights h1, h2 of the connecting edges 16, 16 'of the vortex generators 9, 9' so with the the respective channel heights H1, H2 that the generated Vortex immediately downstream of the vortex generator already such a size that the full channel height H1 + H2 or the full amount of that assigned to the vortex generator Channel part is filled, resulting in an even distribution leads in the loaded cross section. Another one Criterion, which influence on the ratio to be chosen h / H can be taken is the pressure drop that occurs when flowing around the Vortex generator occurs. It goes without saying that with larger Ratio h / H also the pressure loss coefficient increases.

Through targeted design and dimensioning the vortex generators have one at given currents simple means at hand, the mixing process as needed to control.

Reference list

1

Partial roof area

2nd

Partial roof area

3rd

Partial floor area

4th

Partial floor area

5

Trailing edge of 1 and 3

6

Trailing edge of 2 and 4

7

top

8th

Intersection

9

Vortex generator

9 '

Vortex generator at the bottom of 22

10th

Connecting edge

11

Side surface

12th

Long edge

13

Side surface

14

Long edge

16

Connecting edge

17th

Axis of symmetry

18th

top

19th

Axis of rotation

20th

Top of 22

21

Bottom of 22

22

partition wall

30th

Connecting edge

41

upper channel

42

lower channel

α

Arrow angle

γ

Angle from 4 and 5 to 22



Angle of attack

h1

Connection edge height 16

h2

Connection edge height 16 '

H1

Height channel 41

H2

Height channel 42

Claims (7)

1. Mixing device for mixing two or more fluids presenting equal or non-equal mass flow rates, wherein said fluids to be mixed flow along a partitioning wall (22) having a plurality of vortex generators (9, 9') on its downstream end, which present surfaces for free flow therearound, with several ones of said generators being disposed side by side, wherein the side surfaces (11, 13) of said vortex generator are flush with one side of said partitioning wall (22) and enclose a pointed angle (α) among them, wherein longitudinally oriented edges (12, 14) of said side surfaces (11, 13) extend at an angle of incidence () relative to said partitioning wall (22) and both side surfaces (11, 13) enclose together a connecting edge (16) that extends orthogonally with respect to said partitioning wall (22) and forms an edge (16) which the flow acts upon first, wherein moreover

   one roof surface consists of two partial roof surfaces (1,2),

   said partial roof surfaces (1, 2) present longitudinally oriented edges and are flush with the edges (12, 14) of said side surfaces (11, 13),

   said partial roof surfaces (1, 2) are connected to each other via a connecting edge (10),

   the downstream rear edges (5, 6) of said partial roof surfaces (1, 2) enclose with said partitioning wall (22) an angle (y) such that said rear edges (5, 6) are substantially located on the other side of said partitioning wall, relative to said side surfaces (11, 13), and

   a bottom surface consists of two partial bottom surfaces (3, 4) connected to each other via a connecting edge (30) and to said partial roof surfaces (1, 2) via said rear edges (5, 6).
2. Mixing device according to Claim 1,
   characterised in

   that said partial bottom surfaces (3, 4) are formed by said partitioning wall (22) and

   that said vortex generator (9, 9') consisting of two side surfaces (11, 13) and two partial roof surfaces (1, 2) is disposed on said partitioning wall (22).
3. Mixing device according to Claim 1,
   characterised in that said rear edges (5, 6) of said partial roof surfaces (1, 2) are disposed in a plane orthogonal on an axis of symmetry (17).
4. Mixing device according to Claim 1, characterised in that said two side surfaces (11, 13) enclosing said pointed angle (α) as well as said partial roof surfaces (1, 2) of said vortex generator (9) are disposed in symmetry to a plane of symmetry formed by an axis of symmetry (17) and said connecting edge (16).
5. Mixing device according to Claim 1, characterised in that said connecting edge (16) and/or said longitudinally oriented edges (12, 14) of said roof surface present a sharp configuration.
6. Mixing device according to Claim 1, characterised in that said partitioning wall (22) is disposed in a dual-channel container, with two partial channels (41; 42) being formed, and that the same number of vortex generators (9, 9') is disposed in each partial channel, and that said vortex generators are fastened on both sides on said partitioning wall (22).
7. Mixing device according to Claim 6, characterised in that the ratio of the height (h1, h2) of said vortex generator (9, 9') to the height (H1, H2) of said partial channel (41, 42) is so selected that the vortex so generated covers the complete height (H1, H2) of said partial channel or the complete height of said channel (H1+H2) directly downstream of said vortex generator.

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