EP2566628B1 - Atomizer with a lattice mixer - Google Patents

Description

The invention relates to an atomizer, in particular a rotary atomizer, for the application of a multi-component coating agent.

In modern paint shops for painting motor vehicle body components usually rotary atomizers are used as application device, which can also apply partially multi-component paints, which consist of several coating agent components, such as a parent lacquer and a hardener. It is important here that the various components of the multicomponent paint in the atomizer are mixed together as well as possible. For this purpose, the conventional rotary atomizers on static spiral mixers, which are also referred to as Kenics ^® mixer. These spiral mixers have numerous helical mixing elements which direct the coating agent flow radially outwards and then lead back to the center. Usually, two separate spiral mixers are used in this case, the first spiral mixer being arranged in the color tube of the rotary atomizer, while the second spiral mixer is located outside the color tube in the connection block of the rotary atomizer.

A disadvantage of this conventional construction is the fact that a relatively large length of the mixer is required, so that occur in a color change or rinsing large losses of paint or detergent.

Further disclosed DE 82 31 663 U1 a color guide tube in an atomizer, wherein in the color guide tube, a static mixer is arranged. However, this known mixer requires a relatively large length.

Furthermore, it should be noted on the prior art DE 30 40 136 A1 and US 4,614,440 ,

Further disclosed US 2004/0114461 A1 a so-called lattice mixer, which is a static mixer used for mixing high viscosity liquids, for example in injection molding machines. So far, however, such lattice mixers were not used in atomizers, especially since it was assumed that such lattice mixers are only suitable for mixing of highly viscous liquids.

Furthermore, it should be noted on the prior art US 2006/0192033 A1 and WO 2008/136827 A1 ,

Finally revealed FR 2 890 876 A1 an atomizer according to the preamble of the main claim. A disadvantage of this known atomizer with a lattice mixer, however, is the unsatisfactory mixing effect of the lattice mixer.

The invention is therefore based on the object to provide a correspondingly improved atomizer with a structurally integrated mixer.

This object is achieved by an atomizer according to the invention according to the main claim.

The invention includes the general technical teaching to use a different mixer type, namely a so-called lattice mixer, which has numerous mixing elements, the are arranged grid-like interlocked. Such lattice mixers are made, for example US 2004/0114461 A1 so that the content of this document is fully within the scope of the present description in terms of the construction and operation of a lattice mixer.

A common feature of the novel mixer according to the invention with the conventional spiral mixer is that it is static mixers in both cases. This means that the mixer itself has no moving parts, since the mixture is caused by the flow movement of the coating agent components to be mixed together.

In contrast, the new lattice mixer according to the invention differs from the conventional spiral mixer by the arrangement and design of the individual mixing elements. Thus, the conventionally used spiral mixer has spiral mixing elements which divert the coating medium flow in a spiral manner, wherein the mixing elements adjacent in the direction of flow each have opposite directions of deflection, whereby the mixture is effected. By contrast, the lattice mixer used according to the invention preferably has elongate, straight, sharp-edged and rod-shaped mixing elements which consist of plastic and each have a substantially rectangular cross-section. Thus, these mixing elements each cause turbulence, which lead to an effective mixing of the coating agent components to be mixed together.

The individual mixing elements are in this case arranged in a grid-like manner in one another. In the preferred embodiment of the grid mixer according to the invention a plurality of rod-shaped mixing elements are arranged together in one plane and thus form a grid, wherein a plurality of such grids of several mixing elements are arranged interlaced.

It should also be mentioned that the individual mixing elements preferably have a certain angle of incidence relative to the flow direction. This means that the individual Mixing elements are not aligned parallel to the flow direction, since this would only lead to a low mixing effect. Preferably, the angle of attack of the mixing elements with respect to the flow direction is greater than 20 °, 30 ° or 40 ° and / or less than 70 °, 60 ° or 50 °. In the preferred embodiment, the angle of attack is substantially the same for all mixing elements. However, there is also the alternative possibility that the mixing elements have different angles of incidence.

Here, the mixer has several sections, which are arranged one behind the other in the flow direction and are flowed through in succession. The different sections may differ, for example, due to the orientation of the mixing elements. For example, the angle of attack of the mixing elements can vary relative to the flow direction between the sections. In the preferred embodiment of the invention, the mixer has a total of more than 5, 6, 7, 8, 9, 10 or even more than 11 different sections. In this case, there is the possibility that the immediately adjacent sections of the mixer are configured differently, for example, with respect to the angle of attack or the orientation and design of the mixing elements, wherein the next but one section of the mixer again has the same structure.

It should also be mentioned that the mixer is preferably elongated in the flow direction and has a substantially cylindrical cross section, wherein the mixer is preferably arranged completely inside the atomizer.

It is also important that the mixer preferably has a length in the flow direction, which is smaller than 10cm, 8cm or even 6cm. This advantageously makes it possible for the mixer to be arranged completely in the paint tube of the atomizer. The length of the mixer is therefore preferably smaller than the overall length of the paint tube of the atomizer.

The atomizer according to the invention has in the preferred embodiment - as well as the conventional atomizers - a controllable main needle valve, which selectively releases or blocks the coating agent stream. When the main needle valve is closed, the atomizer therefore does not apply any coating agent, so that the valve position of the main needle valve determines whether the atomizer applies the coating agent or not. The mixer is in this case arranged upstream of the main needle valve, so that the ready-mixed coating agent is present at the main needle valve. In this case, it is advantageous if the mixer is displaced as far upstream as possible to the main needle valve in order to minimize the distance between the downstream end of the mixer and the main needle valve. This is advantageous because it reduces the paint or solvent consumption during a color change or when rinsing. The conduit length between the downstream end of the mixer and the main needle valve is therefore preferably shorter than 10cm, 6cm, 5cm, 4cm, 3cm, 2cm or even shorter than 1cm.

It has already been mentioned above that the atomiser according to the invention-like the conventional atomizers-has a hollow color tube in order to supply the coating agent to be applied. The advantages of the lattice mixer according to the invention in this case offer the possibility that the mixer is arranged completely in the paint tube, so that under Can be dispensed with an additional mixer in the terminal block of the atomizer, which was required in the conventional atomizer described above. It should be noted that the paint tube can also form the sheath of the usually cylindrical mixer, so that can be dispensed with an additional mixing tube for sheathing the mixer. It should also be mentioned that, in one embodiment, the diameter of the mixer essentially corresponds to the diameter of the color tube, so that the mixer completely fills the cross section of the color tube. However, it is within the scope of the invention, the possibility that several mixers are arranged side by side in the paint tube of the atomizer, which will be described in detail.

This is useful, for example, if the atomizer is suitable for the application of different coating systems, wherein each of the two coating systems has several components, in particular a master paint and a hardener. Each of the two paint systems can then each be assigned a mixer to mix the components of the paint system with each other.

Here, as already briefly mentioned above, there is the possibility that the mixers for the different paint systems are arranged together in the paint tube, wherein the mixers for the different paint systems are preferably adjacent to one another with respect to the flow direction. Each mixer for the different paint systems then fills only a part of the cross section of the paint tube. Moreover, the various mixers are then preferably sheathed by a mixing tube to separate the various mixers.

It should also be mentioned that the mixers for the different color systems can have different mixing properties, which are adapted to the properties of the respective color system in order to achieve the best possible mixing result.

Alternatively, there is also the possibility that the mixers for the various paint systems are not arranged together in the paint tube. Thus, the mixer for the one paint system can be arranged in the paint tube, while the mixer for the other color system is outside the color tube, for example, in a valve or connection block of the atomizer upstream of the paint tube.

It should generally be mentioned that the atomiser according to the invention can have a plurality of mixers, which may also be useful in general for optimizing the mixing result.

Finally, the invention also encompasses the novel use of a lattice mixer with a plurality of lattice-shaped mixing elements intermeshed in one another for mixing a plurality of components of a coating agent in an atomizer, in particular in a rotary atomizer.

Figur 1:

eine schematisierte Querschnittszeichnung eines erfindungsgemäßen Rotationszerstäubers mit einem integrierten Gittermischer,

Figur 2:

eine Perspektivansicht des Gittermischers aus dem Rotationszerstäuber gemäß Figur 1,

Figur 3:

ein vereinfachtes Diagramm zur Verdeutlichung des Aufbaus eines Rotationszerstäubers zur Applikation von zwei verschiedenen Lacksystemen, wobei in das Farbrohr des Rotationszerstäubers zwei Mischer integriert sind,

Figur 4:

eine Abwandlung von Figur 3, wobei der eine Mischer in dem Farbrohr angeordnet ist, während sich der andere Mischer in dem Ventilblock befindet.

Other advantageous developments of the invention are characterized in the subclaims or are explained in more detail below together with the description of the preferred embodiments of the invention with reference to FIGS. Show it:

FIG. 1:

a schematic cross-sectional drawing of a rotary atomizer according to the invention with an integrated lattice mixer,

FIG. 2:

a perspective view of the lattice mixer from the rotary atomizer according to FIG. 1 .

FIG. 3:

a simplified diagram to illustrate the structure of a rotary atomizer for the application of two different paint systems, wherein in the paint tube of the rotary atomizer two mixers are integrated,

FIG. 4:

a modification of FIG. 3 wherein one mixer is disposed in the paint tube while the other mixer is in the valve block.

FIG. 1 shows a rotary atomizer 1 according to the invention, which can be used for example for painting motor vehicle body components, the rotary atomizer 1 is constructed largely conventional, so that can be dispensed with a detailed description of the structure and operation of the rotary atomizer 1. For the description of the invention is only important that the rotary atomizer 1 has a color tube 2 which is fixed to a terminal block 3, wherein the color tube 2 is aligned coaxially to the axis of rotation of a bell-plate shaft 4 to supply the coating agent to be applied.

The invention now provides that a lattice mixer 5 is arranged in the paint tube 2 in order to mix the various components (for example base lacquer and hardener) of the coating composition.

The lattice mixer 5 has numerous elongated, rod-shaped, sharp-edged mixing elements 6, which are arranged interlaced in a grid shape, wherein the mixing elements 6 generate turbulence in the paint tube 2, resulting in a good mixing.

The lattice mixer consists of a total of twelve sections 7, 8, which are arranged one behind the other in the flow direction, and are flowed through successively. The different sections 7, 8 of the lattice mixer 5 differ here by the orientation of the individual mixing elements 6, as shown in the perspective view in FIG. 2 is apparent.

FIG. 3 shows a schematic diagram to illustrate the structure of a rotary atomizer 9 according to the invention, which is suitable for the application of two different paint systems, wherein the first paint system consists of a first parent paint SL1 and a first hardener H1, while the second paint system of a second parent paint SL2 and a second hardener H2 exists.

For application of the various paint systems, the rotary atomizer has two main needle valves 10, 11 and in each case a lattice mixer 12, 13, wherein the two lattice mixers 12, 13 are arranged together next to one another in a paint tube 14 of the rotary atomizer 9. In this case, the lattice mixer 12 mixes the first stock paint SL1 with the first hardener H1, while the other lattice mixer 13 mixes the second stock paint SL2 with the second hardener H2.

The two lattice mixers 12, 13 in this case correspond in structure and function to the lattice mixer 5 according to FIGS FIGS. 1 and 2 ,

In addition, the rotary atomizer 9 also in this embodiment, a connection block 15 with integrated valves.

It can also be seen from the drawing that the two lattice mixers 12, 13 are arranged at a very short distance 1 <5 cm upstream of the associated main needle valves 10, 11. This is advantageous because the line section to be flushed between the lattice mixers 12, 13 and the associated main needle valves 10, 11 thereby has a low volume, so that the flushing agent losses and the lacquer losses are correspondingly small.

FIG. 4 shows a modification of the embodiment according to FIG. 3 In order to avoid repetition, reference is made to the above description, wherein the same reference numerals are used for corresponding details.

A special feature of this embodiment is the arrangement of the two lattice mixers 12, 13. Thus, the lattice mixer 12 is in this embodiment also within the paint tube 14, whereas the other lattice mixer 13 is integrated into the terminal block 15.

The invention is not limited to the preferred embodiments described above. Rather, a variety of variants and modifications is possible, which also make use of the inventive idea and therefore fall within the scope. It should also be mentioned that the invention also claims protection for the subject matter of the dependent claims independently of the features of the preceding claims.

LIST OF REFERENCE NUMBERS

1

rotary atomizers

2

Farbrohr

3

terminal block

4

Bell cup shaft

5

grid mixer

6

mixing elements

7

Section of the lattice mixer

8th

Section of the lattice mixer

9

rotary atomizers

10

Main needle valve

11

Main needle valve

12

grid mixer

13

grid mixer

14

Farbrohr

15

terminal block

H1

First hardener

H2

Second hardener

1

Cable length between lattice mixer and main needle valve

SL1

First base coat

SL2

Second base coat

Claims (12)

1. An atomizer (1; 9), particularly a rotary atomizer, for the application of a coating agent consisting of several components, with

   a) a static mixer (5; 12, 13) which mixes the various components (SL1, H1, SL2, H2) of the coating agent with one another, wherein the mixer (5; 12, 13) has a plurality of fixed mixing elements (6) and is constructionally integrated into the atomizer (1; 9),

   b) wherein the mixer (5; 12, 13) is a lattice mixer, in which the mixing elements (6) are arranged intertwined in a lattice-like manner,

   c) wherein the mixer (5; 12, 13) comprises a plurality of sections (7, 8) which are arranged one behind the other in the direction of flow and through which the flow successively passes,

   characterized in that

   d) the mixing elements (6) in the adjacent sections (7, 8) of the mixer (5; 12, 13) in the direction of flow are aligned differently, so that the different section (7, 8) differ in the alignment of the mixing elements (6).
2. The atomizer (1; 9) according to Claim 1,
   characterized in that

   a) the individual mixing elements (6) have an essentially rectangular cross section in each case, and/or

   b) the individual mixing elements (6) are elongated in each case, and/or

   c) the individual mixing elements (6) are straight in each case, and/or

   d) the individual mixing elements (6) are sharp-edged in each case, and/or

   e) the individual mixing elements (6) are rod-shaped in each case, and/or

   f) the individual mixing elements (6) consist of plastic.
3. The atomizer (1; 9) according to any one of the preceding claims, characterized in that

   a) the individual mixing elements (6) have a certain pitch angle relative to the direction of flow, and/or

   b) the pitch angle of the mixing elements (6) is greater than 20°, 30° or 40° and/or smaller than 70°, 60° or 50°, and/or

   c) the pitch angle for all mixing elements (6) is essentially the same.
4. The atomizer (1; 9) according to any one of the preceding claims, characterized in that

   a) the number of sections of the mixer (5; 12, 13) is larger than 5, 6, 7, 8, 9, 10 or 11, and/or

   b) the mixer (5; 12, 13) is elongated in the direction of flow, and/or

   c) the mixer (5; 12, 13) is essentially cylindrical, and/or

   d) the mixer (5; 12, 13) has an overall length of less than 10cm, 8cm or 6cm, and/or

   e) the mixer (5; 12, 13) is arranged completely within the atomizer (1; 9).
5. The atomizer (1; 9) according to any one of the preceding claims, characterized in that

   a) the atomizer (1; 9) has a controllable main needle valve (10, 11) which determines whether the atomizer (1; 9) applies the coating agent or not as a function of the valve position thereof, and

   b) the mixer (5; 12, 13) is arranged upstream of the main needle valve (10, 11), and

   c) a line length (1) lies between the end of the mixer (5; 12, 13) positioned downstream and the main needle valve (10, 11), which is shorter than 10cm, 6cm or 5cm.
6. The atomizer (1; 9) according to any one of the preceding claims, characterized in that

   a) the atomizer (1; 9) has a hollow paint tube (14) in order to supply the coating agent, and

   b) the mixer (5; 12, 13) is arranged completely in the paint tube (14), and/or

   c) the mixing elements (6) are arranged without an additional mixing tube in the paint tube (14), and/or

   d) the diameter of the mixer (5; 12, 13) essentially corresponds to the diameter of the paint tube (14), so that the mixer (5; 12, 13) fills the cross section of the paint tube (14) completely.
7. The atomizer (1; 9) according to any one of the preceding claims, characterized in that

   a) the atomizer (1; 9) is suitable for application of at least two different paint systems, wherein each of the two paint systems has a plurality of components, particularly a base paint (SL1, SL2) and a hardener (H1, H2), and

   b) the atomizer (1; 9) for each of the two paint systems has a mixer (5; 12, 13) in each case, wherein the mixers (5; 12, 13) are constructionally integrated into the atomizer (1; 9).
8. The atomizer (1; 9) according to Claims 6 and 7,
   characterized in that

   a) the mixers (5; 12, 13) for the various paint systems are arranged together in the paint tube (14), and/or

   b) the mixers (5; 12, 13) for the various paint systems are arranged adjacently with respect to the direction of flow, and/or

   c) the mixers (5; 12, 13) for the various paint systems in each case only fill part of the cross section of the paint tube (14), and/or

   d) the mixers (5; 12, 13) for the various paint systems in each case have a mixing tube in which the mixing elements (6) are arranged, wherein the mixing tubes separate the mixers (5; 12, 13) from one another, and/or

   e) the mixers (5; 12, 13) for the various paint systems have different mixing properties which are adapted to the properties of the respective paint system.
9. The atomizer (1; 9) according to Claim 6 and 7,
   characterized in that the mixer (5; 12, 13) for one paint system is arranged in the paint tube (14), whilst the mixer (5; 12, 13) for the other paint system is located outside of the paint tube (14), for example in a valve block of the atomizer (1; 9) upstream of the paint tube (14).
10. The atomizer (1; 9) according to one of the preceding claims, characterized in that a plurality of mixers (5; 12, 13) are arranged in the atomizer (1; 9).
11. The atomizer (1; 9) according to one of the preceding claims, characterized in that

    a) the immediately adjacent section (7, 8) of the mixer (5; 12, 13) are each differently designed, and

    b) the next but one section (7, 8) of the mixer (5; 12, 13) each comprises the same structure.
12. A use of a lattice mixer (5; 12, 13) according to any of the preceding claims with a plurality of mixing elements (6) intertwined in a lattice-like manner for mixing a plurality of components (SL1, H1, SL2, H2) of a coating agent in an atomizer (1; 9), particularly in a rotary atomizer.

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