DE102016119306A1 - Device for mixing fluid streams - Google Patents

Abstract

A device (10) for mixing two fluid streams (A, S) is proposed, comprising: a line section (11) having a longitudinal extent for a first fluid stream (A); and an annular flow space (12) disposed around at least a portion of the longitudinal extent around the conduit portion (11); at least one supply line (13) to the annular flow space (12) for introducing a second fluid flow (S) into the annular flow space (12); and at least one of the following feature complexes a) and b): a) a number of apertures (14; 14.1-14.5) in a wall (15) separating the annular flow space (12) from the conduit section (11), which at least one passage Allow part of the second fluid flow (S) from the annular flow space (12) in the line section (11); b) a wall (15) which separates the annular flow space (12) from the line section (11), which wall (15) is connected to a free end (15 ') in an area in the line section (11) or an extension (22 ) thereof so that the annular flow space (12) is in fluid communication with an interior of the conduit section (11) via an air gap (21), preferably on a side facing the first fluid flow (A), most preferably the wall (15) in the region has a flow component transverse to the first fluid flow (A). As a result, a homogeneous mixing of the fluid streams (A, S) can be achieved without significant pressure losses.

Description

The present invention relates to a device for mixing two fluid streams according to claim 1.

In order to meet future exhaust emission limits in the real driving cycle, further measures to reduce particulate emissions are also required for gasoline engines. It is foreseeable that in this context increasingly Ottopartikelfilter (OPF) will be used. OPF are used in the underfloor area of a motor vehicle and lie in the flow direction of the exhaust gas flow behind a catalyst (KAT) and a regularly existing decoupling element (EKE). In order to be able to regenerate the OPF, oxygen is required in the exhaust gas flow, which however has to be supplied separately in the gasoline engine since, unlike the diesel engine, it is operated without excess oxygen.

According to the prior art, air is blown into the exhaust system, that is to say into the exhaust gas stream, by means of a so-called secondary air pump for regenerating the OPF. This happens behind the KAT and before the EKE via a so-called secondary air line. This secondary air line is connected to the prior art via a flange or a V-profile clamp to the exhaust system. The supply of secondary air to the exhaust gas flow is accordingly only "selectively", with a homogeneous mixing of the exhaust gas flow and the secondary air is not guaranteed to the OPF to a sufficient extent. The regeneration of the OPF therefore does not occur over the entire surface, so that correspondingly not the entire surface of the OPF can be used to oxidize particles and thereby reduce the particle emission.

In order to ensure the most homogeneous possible mixing of secondary air and exhaust gas flow on the available, short distance between KAT and OPF, a so-called mixer in the exhaust system is arranged behind or at the point of introduction of secondary air into the exhaust system according to the prior art, for example in the form of an impeller , This can help to distribute the secondary air more evenly in the exhaust gas flow. The provision of a mixer, however, is associated with significant pressure losses, which in turn leads to an increase in fuel consumption.

The invention has for its object to achieve a uniform and homogeneous as possible supply of secondary air to the exhaust stream to make an OPF usable as efficiently as possible without causing pressure losses or fuel consumption increases.

This object is achieved by a device having the features of claim 1. Advantageous developments of the solution according to the invention are the subject of subclaims.

A device according to the invention for mixing two fluid streams has the following components: a line section with a longitudinal extent for a first fluid stream; and an annular flow space disposed around at least a portion of the longitudinal extent around the conduit portion; at least one supply line to the annular flow space for introducing a second fluid flow into the annular flow space; and at least one of the following feature complexes a) and b): a) a number of apertures in a wall separating the annular flow space from the conduit section, allowing passage of at least a portion of the second fluid stream from the annular flow space into the conduit section; b) a wall separating the annular flow space from the conduit section, which wall extends into the conduit section or an extension thereof with a free end in an area, such that the annular flow space in the area is in fluid communication with an interior of the conduit section via an air gap is, preferably on a first fluid flow side facing, wherein most preferably the wall in the region has a flow component transverse to the first fluid flow. The air gap can be formed completely or only over peripheral areas throughout.

According to the invention thus, the supply of the secondary air, that is, the second fluid flow, to the first fluid flow, that is, the exhaust gas over the circumference of the line section, whereby a uniform mixing can be achieved substantially without pressure loss. In this way, an increased fuel consumption is avoided, and the OPF can fully develop its exhaust gas purifying effect due to improved regeneration.

A first development of the device according to the invention provides that at least one breakthrough is provided in the region of a part of the line section, which part is provided downstream of the part of the line section surrounded by the annular flow space with respect to a flow direction of the first fluid. The particular advantage of this embodiment is that can be used for concrete structural realization on existing components of exhaust systems. That part of the device according to the invention which comprises the annular flow space can in this way be a conventional EKE known per se be arranged upstream, so that with respect to a direction of flow of the first fluid flow downstream arranged part is at least partially formed by a winding tube, as it is regularly used in conventional EKE for isolation purposes and for flow guidance. It can further be provided that the at least one breakthrough is formed by an inherent leakage of the winding tube: winding tubes regularly have due to their special design a certain leakage to fluids, in particular gases, which can be specifically used in the context of the present invention to to uniformly mix the second fluid stream (secondary air) with the first fluid stream (exhaust gas) by circumferentially flowing into the conduit section.

Furthermore, it can be provided in the context of this embodiment that the winding tube is surrounded on the outside by a fluid-tight conduit element, in particular a bellows, as is known from conventional EKE.

The annular flow space of a device according to the invention is thus correspondingly in fluidic operative connection with the circumferential gap between the inner winding tube and the bellows provided on the outside, in which case - as already stated - via the leaks of the winding tube, the second fluid (secondary air) which has flowed into the annular flow space uniformly with the content of the winding tube flowing first fluid (exhaust) is miscible.

On the other hand, another preferred development of the device according to the invention provides that at least one opening is provided in the region of the part of the line section surrounded by the annular flow space, in which region the line section can preferably be designed as a rigid pipe section.

It has been found that under some circumstances the air pump used to introduce the secondary air is not sufficiently strong to ensure mixing of the two fluid streams solely through the inherent leakage points of a coiled tubing. In this context, and without limitation thereto, it has proved to be advantageous, alternatively or additionally, in the region of the part of the line section surrounded by the annular flow space, which line section can be formed as a rigid pipe section at least in this area (through openings for the inflow of the second) Provide fluid flow in said line section.

In the course of a particularly preferred embodiment of the device according to the invention may be provided in this context that a plurality of openings are provided, which openings may be preferably distributed over the circumference of the line section. The above-mentioned distribution over the circumference of the line section ensures a further improvement of the homogenization and for a reduction of pressure losses.

In the course of a preferred development of the device according to the invention, it can further be provided in this connection that the apertures are distributed uniformly over the circumference of the line section and thereby have at least partially different opening cross sections. The provision of different opening cross-sections can further contribute to avoiding or reducing pressure losses. It has proved to be particularly advantageous if the opening cross-section of each aperture is greater, the further the respective aperture is arranged away from a location of the feed line. This can mean, for example, that a breakthrough arranged exactly opposite the feed line has a maximum opening cross section, while an opening immediately adjacent to the feed line has a relatively small opening cross section.

Alternatively or additionally, however, it may also be provided that the apertures are distributed unevenly over the circumference of the line section and thereby have substantially the same opening cross-sections. This also makes it possible in particular to avoid or reduce pressure losses. It may be provided that a distance between adjacent openings is smaller, the further the respective adjacent openings are arranged away from a location of the supply line. In other words: far away from the supply line there are relatively many (equal) openings per unit area, while only relatively few such openings are provided in the vicinity of the supply line.

It has proved to be particularly advantageous to avoid pressure losses when a sum of opening cross sections of the apertures corresponds approximately to an opening cross section of the supply line.

In order to further improve the mixing of the two fluid streams, in a further development of the device according to the invention it can also be provided that at least one flow guiding element is provided in an edge region of at least one opening, which projects into the line section at a certain angle. such Flow guiding elements can further improve the mixing. Within the scope of another preferred development of the invention, it can be provided in this connection that the flow-guiding element is formed by a punch-out produced during the creation of the opening, which represents a structurally particularly simple variant. If a plurality of openings is realized, each breakthrough may have such a flow guide. It can be provided that the flow guide are most preferably formed or oriented differently from breakthrough to breakthrough in order to favor the mixing.

Yet another development of the device according to the invention can provide that the line section has a substantially constant cross section over the part surrounded by the annular flow space. However, the invention is by no means limited to such a configuration.

Furthermore, within the scope of another development of the device according to the invention, provision may be made for the line section upstream and / or downstream of the part surrounded by the annular flow space to have a cross-sectional change. This cross-sectional change may be formed in particular as a cross-sectional widening. In addition, it can be provided with appropriate development of the device according to the invention that the line section is formed substantially straight. Such embodiments have proven to be particularly flexible in practice.

In another development of the device according to the invention can be provided that the air gap has a circumference of the wall has a variable width, wherein the air gap is preferably narrower in the vicinity of the supply line than at a greater distance from the supply line. As a result, similar advantages can be achieved as in the case of the above-proposed embodiments with a larger breakthrough area at a greater distance from the supply line.

In addition, it can be provided in development of the device according to the invention that the wall at its free end in cross section has a variable geometry over its circumference with circumferentially different distances from a longitudinal axis of the device or the line section, in particular a star shape. As a result, the aforementioned flow component can be realized in a structurally simple manner transversely to the first fluid flow, which contributes to an efficient mixing of the fluid flows.

With a corresponding development, the device according to the invention can be integrated into a line arrangement, wherein it can be provided that the line section of the device is formed integrally with another component of this line arrangement. In this way, the advantages of the present invention can be used without having to use additional components for this purpose.

Depending on the intended application, the device according to the invention may be formed in metal and / or in plastic in a corresponding development. The aforementioned applications in the field of exhaust systems of motor vehicles with internal combustion engine regularly require an embodiment of the device in metal.

Another possible use of the device according to the invention is in the area of the return of fuel or fuel vapors. There, the device may be formed in plastic due to the significantly lower temperatures.

Another possible use of the device according to the invention is in the field of injection of liquid urea in an exhaust stream, as is common today, for example in diesel vehicles. In this context, it can be provided in a corresponding development of the device according to the invention that upstream of the feed line, in fluidly operative connection with this, and / or in the feed line itself and / or in a region of at least one opening a woven or knitted fabric, preferably made of metal , which is designed and intended to comminute droplets of a liquid introduced or injected into the second fluid stream, for example urea.

As already mentioned, the particular advantages of the present invention, namely the uniform mixing of two fluid streams essentially without pressure loss, can be used not only for the introduction of secondary air for the regeneration of an OPF. By way of example, reference has already been made in this connection to the recycling of fuel / fuel vapors or the urea injection.

A first preferred use of the device according to the invention is therefore in the field of injection of secondary air in an exhaust stream upstream of an exhaust gas particulate filter, wherein as the first fluid stream, an exhaust gas stream is passed through the device, and as the second fluid stream secondary air or fresh air in the Supply line is initiated.

Another preferred use of the device according to the invention is in the context of fuel recovery in an internal combustion engine, as the first fluid stream of combustion air is passed through the device, and wherein as a second fluid stream at least partially fuel vapor is introduced into the supply line.

Finally, another preferred use of the device according to the invention in the field of urea admixture in the exhaust line of an internal combustion engine, in particular a diesel engine, wherein as the first fluid stream, an exhaust gas stream is passed through the device, and wherein as the second fluid stream of air and / or exhaust gas with added (injected) Urea is introduced into the supply line.

Further features and advantages of the invention will become apparent from the following description of exemplary embodiments with reference to the drawing.

1 schematically shows the flow conditions when injecting secondary air into the exhaust system of a motor vehicle with gasoline engine;

2 schematically shows a first embodiment of the device according to the invention in longitudinal section;

3 shows schematically simplified another embodiment of the device according to the invention in longitudinal section;

4 shows schematically simplified another embodiment of the device according to the invention in longitudinal section;

5 shows a further embodiment of the device according to the invention in longitudinal section;

6 shows a still different embodiment of the device according to the invention in longitudinal section;

7 shows schematically the use of a device according to the invention in connection with a fuel recovery;

8th shows schematically the use of a device according to the invention in connection with the injection of urea;

9 shows a view into an apparatus according to the invention in the direction of the exhaust gas jet;

10 shows a representation analog 9 in another embodiment of the device according to the invention;

11 schematically shows a variant of the device according to the invention 2 in longitudinal section;

12 schematically shows a variant of the device according to the invention 11 in longitudinal section; and

13 schematically shows a variant of the device according to the invention 12 in longitudinal section.

1 shows purely schematically in the form of a block diagram, the fluidic relationships in the injection of secondary air into the exhaust system of a car with gasoline engine. Here, the secondary air pump (see below at reference numerals 4 ) motor-proof or fixed unit installed. The arrows indicate flow directions of the respective fluids (secondary air or exhaust gas). reference numeral 1 denotes a catalyst (KAT), reference numerals 2 denotes a decoupling element EKE, reference numeral 3 denotes an Otto particle filter (OPF). Accordingly, an exhaust gas stream A first enters the CAT 1 , then in the EKE 2 and from there to the OPF 3 , reference numeral 4 symbolizes an arrangement or device for injecting secondary air S. This is regularly between KAT 1 and EKE 2 introduced into the exhaust system (exhaust stream A). It should ensure that there is enough oxygen in the exhaust gas to the OPF 3 to regenerate to its full effectiveness in reducing particulate emissions.

If alternative to the illustration in 1 the secondary air pump is fixed to the frame, the injection of the secondary air S takes place deviating between EKE and OPF.

2 shows a schematic longitudinal sectional view of an embodiment of the device according to the invention for mixing two fluid streams, which can be used in particular for the most homogeneous possible introduction of secondary air into an exhaust gas stream. In 2 again, reference symbol A denotes the exhaust gas or the exhaust gas flow, while reference symbol S symbolizes the secondary air. The exhaust gas flow A thus represents a first fluid flow, while the secondary air S represents a second fluid flow. These two fluid streams should be mixed as homogeneously as possible. For this purpose, the device according to the invention, the total with the reference numeral 10 is designated, an inner line section before, which has a certain longitudinal extent and in 2 with the reference number 11 is designated. The pipe section 11 serves for introducing or passing the exhaust stream A, so the first fluid stream. Furthermore, the device comprises 11 an annular flow chamber 12 at least over part of the longitudinal extent around the line section 11 is arranged around. According to the embodiment in 2 extends the annular flow space 12 in the longitudinal direction substantially over the entire length of the line section 11 around. To the annular flow space 12 is a supply line 13 provided for introducing the second fluid stream, namely the secondary air S, in the annular flow space 12 serves. Furthermore, the device comprises 10 a number of breakthroughs 14.1 - 14.5 that in a the annular flow space 12 from the pipe section 11 separating wall 15 are arranged. The breakthroughs 14.1 - 14.5 allow a passage of at least a portion of the second fluid stream S from the annular flow space 12 in the pipe section 11 , According to 2 are corresponding breakthroughs 14.1 - 14.5 over the entire circumference of the flow space 12 or the line section 11 provided in order to achieve a circumferentially homogeneous mixing of the two fluid streams A, S.

How to get the 2 still takes, are the breakthroughs 14.1 - 14.5 arranged substantially equally spaced from each other over the circumference; however, an opening cross section of the apertures changes 14.1 - 14.5 depending on their circumferential position: so are those breakthroughs 14.1 particularly small trained, located at the place of supply 13 or at the same place where the second fluid flow S on the wall 15 incident. The further the breakthroughs 14.1 - 14.5 are removed from this point, the larger their cross-sectional area. The biggest breakthroughs 14.5 can be found accordingly on the supply line 13 opposite side of the device 10 , The Applicant has found that in this way a particularly good mixing of the exhaust gas flows results in only minimal pressure losses. Preferably, in this context, the summed total opening area of the openings 14.1 - 14.5 just a clear opening cross-section of the device 10 in the area of the supply line 13 ,

The in 2 The fluid flow denoted by the reference A 'includes, in addition to the actual exhaust gas flow A, a sufficient and homogeneous mixing with secondary air S, so that one of the devices 10 downstream OPF can be operated very effectively.

3 shows a greatly simplified and schematically another embodiment of the device according to the invention, in turn, with the reference numeral 10 is designated. Otherwise, the same reference numerals designate the same or equivalent elements.

Like the illustration in 3 clarifies, the invention is not on a (right) angular configuration of the breakthroughs (see. 2 ). Such are the breakthroughs 14.1 - 14.4 at the subject of 3 all circular in shape, again with an opening cross section of the openings 14.1 - 14.4 with increasing circumferential distance from the location of the supply line 13 increases.

4 shows an alternative embodiment of the device 10 in which the breakthroughs 14.1 - 14.6 Although all have the same opening cross-section, but with increasing distance from the location of the supply line 13 are arranged closer adjacent, so that a similar effect results, as he above with a view of the 2 and 3 has already been described: a proportion of the openings in the total area decreases with increasing distance from the supply line 13 to.

However, as those skilled in the art will readily appreciate, the invention is by no means limited to the specific geometries described with reference to FIGS 2 to 4 have been described by way of example.

5 shows a further possible embodiment of the device, in turn, the same or equivalent components are provided with the same reference numerals, as in the preceding figures. An essential difference from the previous embodiments is that the line section 11 in the axial direction of the arrangement, a further line section in the form of the interior 11 ' a winding tube or liner 16 which has an inherent leakage. Outside is the winding tube 16 surrounded by a bellows 17 , as is well known from conventional decoupling elements (EKE). Terminal connections and connecting pieces are in the form of end sleeves 18 . 19 , Between winding hose 16 and bellows 17 is an air gap 20 formed, wherein the annular flow space 12 on his sleeve 18 axially facing away from said air gap 20 passes. The in the annular flow space 12 through the supply line 13 inflowing second fluid flow (secondary air S) thus distributed circumferentially within the air gap 20 and from there via the mentioned leaks of the winding tube 16 in its interior 11 ' where mixing with the exhaust stream A takes place.

In addition to this embodiment can - as in 6 shown - also in the area of the wall 15 between the annular flow space 12 and the line section 11 still breakthroughs 14 (Not all designated) may be provided to improve or accelerate the mixing of the fluid streams S, A. According to the embodiment of 6 the mixing is done so no longer alone the inherent leakage of the winding tube 16 but in addition to the breakthroughs 14 , The latter can in principle be designed as already described with reference to 2 to 4 described. In addition, in the embodiment according to 6 also a series arrangement of breakthroughs 14 provided in the flow direction of the exhaust stream A. The invention can by no means be limited to such an embodiment.

In addition, in the context of the embodiment according to the 2 to 4 Breakthroughs to be arranged in the flow direction one behind the other.

7 shows the use of a device according to the invention 10 , the purely exemplary according to 2 is configured in connection with a fuel recovery in a motor vehicle with an internal combustion engine. reference numeral 30 denotes a fuel tank, from the fuel vapors D as the second fluid stream via the supply line 13 the device 10 be supplied. Reference character L designates a first fluid stream in the form of an air supply for operating an internal combustion engine, of which in 7 schematically exemplary four cylinders 31 are shown. reference numeral 32 denotes a so-called collector, via which an air-fuel mixture the cylinders 31 is fed, which is indicated by corresponding arrows in 7 is symbolized.

The device 10 is used to homogeneously mix the fuel vapors D (second fluid stream) with the air supply L (first fluid flow), to produce in this way a homogeneous mixed air-fuel vapor mixture L ', which via the collector 32 to the cylinders 31 arrives. In this way it is ensured that all cylinders 31 obtained an air-fuel vapor mixture having comparable properties. The device 10 may be formed in plastic in this context. The pipe section 11 can with the collector 32 form an integral component.

8th schematically shows a further possible use of the device 10 as part of the injection of liquid urea into the exhaust system of a diesel engine. Again, the device 10 again schematically exemplary according to 2 configured, without the invention being limited thereto.

reference numeral 40 denotes a tank of aqueous urea solution containing a metering device 41 fluidly connected. The metering device 41 flows into a mixer line 42 who is a mixer 43 and a metallic fine fabric 44 downstream of the droplet reduction. The thus generated fluid flow F with injected urea passes over the supply line 13 into the device 10 ,

reference numeral 45 refers to a diesel particulate filter (DPF). reference numeral 46 denotes a special catalyst in the form of an SCR-KAT. The device 10 supplied first fluid stream consists of the exhaust stream A, which over the DPF 45 into the device 10 arrives. There is a homogeneous mixing with the fluid flow F, which contains finely divided the injected urea. In the fluid flow A ', the device 10 leaves, so it is the exhaust gas stream with homogeneously admixed injected urea. This gets into the SCR-KAT 46 so that it can clean the exhaust stream particularly efficiently.

9 shows a view in the direction of the exhaust stream A in a device according to the invention 10 , To generate the representation according to 9 was a mist mixture through the supply line 13 injected and by means of a at the rear end of the device 10 arranged suction device (not shown) through the line section 11 sucked. How to do the photographic representation in 9 easily removes, it comes to a very homogeneous filling of the interior of the line section 11 with the injected mist mixture, which is denoted by the reference numeral A 'analogous to the previous figures. Good to see in 9 the regularly arranged for the circumference breakthroughs 14 (Not all designated), each a flow guide 14a exhibit. The latter consists of a raised material punching, which in the manufacture of the breakthroughs 14 was formed by means of a corresponding punching process. Again, there is the possibility of the individual breakthroughs in terms of their opening size and also with regard to the design (installation angle and / or size) of the relevant flow guide elements 14a to train differently.

This is particularly clear on the basis of 10 to recognize which an alternative embodiment of the device 10 analogous to the representation in 9 shows. Here it can be clearly seen that in the circumferential direction further from the supply line 13 removed breakthroughs 14 more strongly positioned flow guide elements 14a have, which can have a positive effect on an achievable mixing of the supplied fluid streams.

Due to the achievable with the present invention good mixing of the two supplied fluid streams, a total length of the device according to the invention can be limited to about 140 mm to 250 mm, preferably to about 200 mm (refers to a configuration according to the 5 or 6 with attached EKE (liner and bellows)).

11 shows a variant of the device 10 as stated above by 2 has already been described in detail. The same reference numerals designate the same or equivalent elements, so that initially no further details are given.

According to 11 the essential difference to the embodiment in 2 in that the device 10 on its exhaust gas flow A side facing, that is left in 11 an air gap 21 in the form of an approximately annular opening, in which area the annular flow space 12 to the outside (based on the illustrated device 10 ) opens. In this area can be connected to the device 10 be connected to another line section, as in 11 indicated by dashed lines and with reference numerals 22 designated. A free end 15 ' the wall 15 , which according to the line section 22 protrudes in this respect or with respect to a longitudinal axis LA of the arrangement can be arranged eccentrically or formed, so that for the air gap 21 near the supply line 13 a small width results than on one of the supply line 13 opposite side of the arrangement (below in 11 ). In the field of breakthroughs 14.1 - 14.5 can be realized in this context, all the above-mentioned embodiments.

However, it is also possible the air gap 21 without the in 11 breakthroughs shown 14.1 - 14.5 to realize.

Furthermore, there is the possibility of directed against the flow direction A free end 15 ' the wall 15 to form so that there is a mixing of the secondary air S and the exhaust stream A by mixing. This is in the following 12 exemplified.

12 shows a device 10 , which is a variant of the embodiment according to 11 and as already mentioned, the provision of breakthroughs has been dispensed with. In the left part of the figure, a representation in longitudinal section is shown, while in the right part of the figure, a sectional view along the line BB in the left part of the figure is shown.

How to get the 12 takes off, the free end can 15 ' the wall 15 be retracted inwardly in the direction of the longitudinal axis LA and thereby have in cross section the star-shaped configuration shown in the right part of the figure. This is how the free end works 15 ' the wall 15 and the already mentioned manner as a mixer for the secondary air S and the exhaust gas flow A.

As shown in 12 Can this be the wall? 15 forming pipe section can also be referred to as a star-shaped aufgetulptes piece of pipe. In one area 23 can be provided that said pipe section (wall 15 ) in a delivery state with the supply line 13 and the annular flow space 12 forming component is connected only by stapling or spot welds. The required tightness in this area results after welding in the complete exhaust pipe, in particular after welding with another pipe element at reference numerals 24 ,

Such embodiments are not limited to the concrete, in 12 shown embodiment of the free end 15 ' the wall 15 limited. Thus, for example, the shaping can also take place as shown by way of example in FIG 13 is shown. Specifically, the angle α shown there is not at a certain value (in accordance with 13 about 30 degrees).

Claims (21)

Contraption ( 10 ) for mixing two fluid streams (A, L; S, F, D), comprising: a line section ( 11 ) having a longitudinal extent for a first fluid flow (A, L); and an annular flow space ( 12 ), which at least over part of the longitudinal extent around the line section ( 11 ) is arranged around; at least one supply line ( 13 ) to the annular flow space ( 12 ) for introducing a second fluid flow (S, F, D) into the annular flow space ( 12 ); and at least one of the following feature complexes a) and b): a) a number of breakthroughs ( 14 ; 14.1 - 14.6 ) in a the annular flow space ( 12 ) from the line section ( 11 ) separating wall ( 15 . 16 ), which a passage of at least a portion of the second fluid stream (S, F, D) from the annular flow space ( 12 ) in the line section ( 11 . 11 ' ) enable; b) one the annular flow space ( 12 ) from the line section ( 11 ) separating wall ( 15 ), which wall ( 15 ) with a free end ( 15 ' ) in an area in the line section ( 11 ) or an extension ( 22 ) thereof extends so that the annular flow space ( 12 ) in the area with an interior of the line section ( 11 ) via an air gap ( 21 ) is in fluid communication, preferably on a side facing the first fluid flow (A, L), most preferably the wall ( 15 ) in the region has a flow component transverse to the first fluid stream (A, L). Contraption ( 10 ) according to claim 1, characterized in that at least one breakthrough in the region of a part of the line section ( 11 ' ) is provided, which part with respect to a flow direction of the first fluid (A, L) downstream of the from the annular flow space ( 12 ) surrounded part of the line section ( 11 ) is provided. Contraption ( 10 ) according to claim 2, characterized in that with respect to a flow direction of the first fluid (A, L) arranged downstream part ( 11 ' ) at least in sections through a winding tube ( 16 ), wherein preferably the at least one breakthrough by an inherent leakage of the winding tube ( 16 ) is formed, and most preferably the winding tube ( 16 ) on the outside of a fluid-tight line element, in particular bellows ( 17 ) is surrounded. Contraption ( 10 ) according to one of claims 1 to 3, characterized in that at least one breakthrough ( 14 ; 14.1 - 14.6 ) in the region of the annular flow space ( 12 ) surrounded part of the line section ( 11 ), in which area the line section ( 11 ) is preferably designed as a rigid pipe section. Contraption ( 10 ) according to one of claims 1 to 4, characterized in that a plurality of openings ( 14.1 - 14.6 ) are provided, preferably over a circumference of the line section ( 11 ). Contraption ( 10 ) according to claim 5, characterized in that the openings ( 14.1 - 14.5 ) evenly over the circumference of the line section ( 11 ) are distributed and thereby have at least partially different opening cross sections, wherein preferably the opening cross section is greater, the further a respective breakthrough ( 14.1 - 14.5 ) from a location of the supply line ( 13 ) is located away. Contraption ( 10 ) according to claim 5 or 6, characterized in that the openings ( 14.1 - 14.6 ) unevenly over the circumference of the line section ( 11 ) are distributed and thereby have substantially the same opening cross-sections, wherein preferably a distance between adjacent openings ( 14.1 - 14.6 ), the smaller the further the relevant breakthroughs ( 14.1 - 14.6 ) from a location of the supply line ( 13 ) are arranged away. Contraption ( 10 ) according to one of claims 5 to 7, characterized in that a sum of opening cross sections of the openings ( 14.1 - 14.6 ) about an opening cross-section of the supply line ( 13 ) corresponds. Contraption ( 10 ) according to one of claims 1 to 8, characterized in that in an edge region of at least one breakthrough ( 14 ) at least one flow guide ( 14a ) is provided, which at an angle in the line section ( 11 ) protrudes. Contraption ( 10 ) according to claim 9, characterized in that the flow guide ( 14a ) by one in creating the breakthrough ( 14 ) is formed, and that preferably at a plurality of breakthroughs ( 14 ) every breakthrough ( 14 ) a flow guide ( 14a ), which flow guide elements ( 14a ) most preferably from breakthrough ( 14 ) to breakthrough ( 14 ) are formed differently. Contraption ( 10 ) according to one of claims 1 to 10, characterized in that the line section ( 11 ) over that of the annular flow space ( 12 ) surrounded part has a substantially constant cross-section. Contraption ( 10 ) according to one of claims 1 to 11, characterized in that the line section ( 11 ) upstream and / or downstream of the annular flow space ( 12 ) surrounded part has a cross-sectional change, preferably cross-sectional widening. Contraption ( 10 ) according to one of claims 1 to 12, characterized in that the line section ( 11 ) is essentially straight. Contraption ( 10 ) according to any one of claims 1 to 13, characterized in that it fits into a conduit arrangement ( 11 . 32 ), the line section ( 11 ) in one piece with another component ( 32 ) of this management 11 . 32 ) is trained. Contraption ( 10 ) according to one of claims 1 to 14, characterized in that it is formed in metal and / or in plastic. Contraption ( 10 ) according to one of claims 1 to 15, characterized in that upstream of the supply line ( 13 ), in fluidic operative connection therewith, and / or in the supply line ( 13 ) itself and / or in a region of the at least one opening a tissue ( 44 ) or knitted fabric, preferably made of metal, which is designed and intended to comminute droplets of a liquid introduced into the second fluid stream (F). Contraption ( 10 ) according to one of claims 1 to 16, characterized in that the air gap ( 21 ) a circumference of the wall ( 15 ) has a variable width, wherein the air gap ( 21 ) preferably in the vicinity of the supply line ( 13 ) is narrower than at a greater distance from the supply line ( 13 ). Contraption ( 10 ) according to one of claims 1 to 17, characterized in that the Wall (wall) 15 ) at its free end ( 15 ' ) in cross section a variable geometry over its circumference with circumferentially different distances from a longitudinal axis (LA) of the device ( 10 ) or the line section ( 11 ), in particular a star shape. Use of the device ( 10 ) according to one of claims 1 to 18 for the injection of secondary air (S) into an exhaust gas stream (A) in front of an exhaust gas particle filter ( 3 ), in particular in a gasoline engine, wherein as the first fluid flow (A) an exhaust gas flow through the device ( 10 ), and wherein as the second fluid flow (S) secondary air into the supply line ( 13 ) is initiated. Use of the device ( 10 ) according to one of claims 1 to 18 for fuel return in an internal combustion engine, wherein as the first fluid flow (L) combustion air through the device ( 10 ) is passed, and wherein as a second fluid stream (D) at least partially fuel vapor in the supply line ( 13 ) is initiated. Use of the device ( 10 ) according to any one of claims 1 to 18, particularly preferably according to claim 16, for adding urea into the exhaust gas line of an internal combustion engine, in particular a diesel engine, wherein as the first fluid flow (A) an exhaust gas flow through the device ( 10 ) and wherein as the second fluid flow (F) air and / or exhaust gas with added urea in the supply line ( 13 ) is initiated.

Images