EP3204168B1 - Atomizer nozzle - Google Patents

Description

The invention relates to an atomizer nozzle that can be used on spray devices for spraying liquids. The atomizer nozzle can be arranged on mobile or stationary spray devices.

Atomizer nozzles are used for fine atomization of a liquid supplied to the atomizer nozzle, for example water, or a liquid mixture, which can also have additives, such as cleaning agents or the like. For the sake of simplicity, a liquid is referred to below, wherein such liquid mixtures are also intended to be included. Compressed gas is used to atomize the liquid into fine liquid particles, which is mixed with the liquid in a mixing chamber and supports atomization. The liquid atomized with the aid of the compressed gas is dispensed as an atomized spray jet at at least one outlet opening of the atomizer nozzle.

The atomizing nozzle can be used in various fields of application, for example for spraying fertilizers, pesticides or fungicides in agriculture or for moistening or cooling objects in industrial production, for spraying water and / or cleaning agents or in the chemical industry for evaporation to facilitate the liquid by atomizing. In principle, the atomizer nozzle can be used wherever very fine atomization of a liquid is required.

For example, an atomizer nozzle is off EP 0 714 706 B1 known. The atomizer nozzle has a liquid connection and a gas connection. The liquid connection is fluidly connected to a liquid channel which extends coaxially along a nozzle axis and opens into a mixing chamber. The liquid stream flows as a jet along the nozzle axis into the mixing chamber. Radially to the nozzle axis, several injection channels open into the mixing chamber and are fluidly connected to the gas connection. In the mixing chamber, the axial liquid flow is atomized via the gas flowing transversely thereto and is discharged to the outside along the nozzle axis through an outlet opening.

WO 2008/032088 A1 and EP 0 458 685 A1 each describe atomizer nozzles with features that correspond to the features of the preamble of independent claim 1.

Starting from these known atomizing nozzles, it can be regarded as an object of the invention to achieve improved atomization of the liquid with the aid of gas.

This object is achieved by an atomizer nozzle with the features of claim 1.

The atomizer nozzle has a liquid connection for supplying a liquid. The liquid can be a single liquid or a liquid mixture. The liquid connection is connected to a liquid channel through which the supplied liquid flows and which opens downstream into an annular mixing chamber. The annular mixing chamber surrounds a nozzle axis of the atomizing nozzle in an annular manner and is arranged coaxially with the nozzle axis.

An end section opening directly into the ring mixing chamber widens towards the ring mixing chamber. The outer diameter of the end section becomes larger towards the ring mixing chamber. A central part can preferably be arranged in this end section. The nozzle axis can preferably pass through the central part in the middle. With the aid of an atomizer nozzle, to which the central part belongs, for example, a flow layer is formed from the liquid flowing through the end section, which diverges away from the nozzle axis and is preferably completely closed in a ring shape in the circumferential direction around the nozzle axis. The flow layer is directed obliquely away from the nozzle axis. Preferably, a flow cone-shaped or frustoconical flow layer is formed, which can also be referred to as a liquid film. The means for generating the flow layer has a swirl generating means which gives a swirl to the liquid flowing in the liquid channel.

The annular mixing chamber connects to the end section of the liquid channel. The liquid of the flow layer flows into the annular mixing chamber from the end section.

Compressed gas is supplied to a gas line system of the atomizer nozzle via a gas connection. In principle, any pressurized gas or gas mixture at any temperature and / or pressure can be used as the pressurized gas, regardless of the saturation vapor pressure and / or the critical temperature of the gas or gas mixture. For example, compressed air and / or nitrogen and / or hydrogen can be used as the compressed gas. Steam can also be used as the pressurized gas in some applications, for example Steam.

The gas line system includes at least one outer injection channel and at least one inner injection channel. Compressed gas is introduced into the ring mixing chamber via the injection channels. The outer injection channel opens into an outer injection point and the inner injection channel opens into the ring mixing chamber at an inner injection point. The inner injection point is enclosed by the annular mixing chamber which extends coaxially around the nozzle axis. Viewed radially to the nozzle axis, the outer injection site is on the radially outer side of the ring mixing chamber and the inner injection site is on the radially inner side of the ring mixing chamber.

Thus, the gas flows into the ring mixing chamber from outside and inside and hits the flow layer there. The pressurized gas is directed from the radially outside and radially inside against the frustoconical flow layer. By producing a film-like liquid layer and injecting compressed gas via the two injection points into the ring mixing chamber from opposite sides, a significantly improved atomization of the liquid is achieved. Very small liquid particles can be generated which are discharged downstream through the atomizing nozzle. In addition, the compressed gas consumption required for atomization can be kept low by injecting the compressed gas into the comparatively thin, frustoconical flow layer. The use of the atomizing nozzle therefore reduces the pressure gas consumption, which reduces the operating costs of a spray device equipped with the atomizing nozzle.

The outer injection site and the inner injection site are preferably arranged offset to one another in the direction of extension of the annular mixing chamber. The direction of extension of the annular mixing chamber is to be understood as the course of the median plane through the annular mixing chamber starting at the end section of the liquid channel up to the outer end of the annular mixing chamber in front of the at least one outlet opening. The direction of extension of the annular mixing chamber therefore does not relate to its course in the circumferential direction around the nozzle axis, but at right angles thereto along the central plane. The outer and the inner injection site can also be arranged opposite one another in the direction of extension of the ring mixing chamber.

In one embodiment, the inner injection site is arranged upstream of the outer injection site in the direction of extension of the ring mixing chamber. The pressurized gas supplied via the inner injection point gives the liquid flow a radial component or a flow component towards the outer injection point. Compressed gas is also fed in there, with the excitation or the radially outward flow component producing a further improved atomization into small liquid particles. The gas streams entering from the different directions at the two injection points can also have a shear effect on the flow layer, which is particularly the case when the outer and inner injection points are offset in the direction of extension of the annular mixing chamber, but are arranged close to one another. A spatially close arrangement of the two injection points is understood to mean that the compressed gas flowing in from one of the two injection points at least partially directly onto the other Injection site or a wall section immediately adjacent to the other injection site.

In a preferred embodiment, the inner injection site specifies a main outflow direction that intersects the median plane of the ring mixing chamber at a first angle. Accordingly, the outer injection site can specify a main outflow direction that intersects the median plane of the annular mixing chamber at a second angle. The amount of the second angle is preferably smaller than the amount of the first angle. The first angle can be, for example, in a range from 45 ° to 90 °, preferably between 60 ° and 90 °. The second angle is, for example, less than 70 ° and preferably less than 45 °.

In a preferred embodiment, the gas line system fluidly connects the inner injection channel and the outer injection channel to the gas connection. The compressed gas provided at the gas connection thus flows into both injection channels. The gas line system is designed such that the gas volume flow that flows into the ring mixing chamber via the outer injection channel is greater than the gas volume flow that flows into the ring mixing chamber via the inner injection channel. The gas volume flow flowing into the ring mixing chamber via the outer injection channel can be more than 50% and preferably up to 80% of the total gas volume flow which flows into the ring mixing chamber via the two injection channels. This division allows good atomization with a further reduced compressed gas consumption. Depending on the circumstances and requirements, gas volume flow components can also be used less than 50% or more than 80%.

At least one outlet opening is present downstream of the annular mixing chamber. The spray jet, which contains the liquid atomized by gas, emerges from the at least one outlet opening. Preferably, there are several outlet openings distributed in the circumferential direction around the nozzle axis and, for example, distributed with the same circumferential section. The outlet openings preferably each have a rotationally symmetrical shape and can for example be cylindrical and / or widening and / or designed as a Laval nozzle.

A further improvement in the atomization of the liquid is achieved in one exemplary embodiment in that the annular mixing chamber between the injection points and the at least one outlet opening has a curve that is curved one or more times in the direction of the nozzle axis. In this area, the annular mixing chamber, viewed along the nozzle axis, can curve towards the nozzle axis and / or curve away from the nozzle axis.

In a preferred exemplary embodiment, the annular mixing chamber is designed to be rotationally symmetrical to the nozzle axis.

The atomizing nozzle has the swirl generating means, which is set up to impart a swirl to the liquid flowing into the liquid channel and in particular into the end section of the liquid channel. The swirl generating means can be formed, for example, in that an inflow orifice for supplying the liquid into the liquid channel opposite the nozzle axis is radially offset and aligned obliquely. As a result, the liquid flowing into the liquid channel will already flow helically along the liquid channel with a swirl.

Alternatively or in addition to this, the swirl generating means can have a swirl generator which is arranged in the liquid channel and in particular upstream of the end section of the liquid channel. The swirl generator is flowed through by the liquid and gives a swirl to the liquid flow. This can be done by inclined and / or helical guide surfaces and / or guide channels and / or by a rotor of the swirl generator, e.g. an impeller. In principle, all known swirl generating agents can be used alone or in combination.

It is advantageous if the swirl generator is arranged in a swirl generation section of the liquid channel which adjoins the end section of the liquid channel. The swirl generating section can be arranged, for example, upstream of and in the immediate vicinity of a transition section of the liquid channel which leads to the end section and whose cross section or diameter tapers towards the end section. The flow cross section available for the liquid in the swirl generation section can be essentially constant in the flow direction.

It is also advantageous if the gas line system has a central channel which extends along the nozzle axis in the central part. The central channel opens into the liquid channel in the central part. From the central channel can pressurized gas flow substantially counter to the axial flow direction component of the liquid immediately upstream of the end section of the liquid channel and there contribute to an improved formation of the hollow cone-shaped flow layer.

In one exemplary embodiment, the atomizer nozzle has a nozzle body in which the liquid channel and the annular mixing chamber are formed. The nozzle body is preferably made integrally from a material without a seam and joint. It can preferably be produced by so-called additive manufacturing processes, such as 3D printing processes. It is also preferred if all lines and channels carrying a fluid are formed in this nozzle body. The central part is preferably an integral part of this nozzle body.

• Figur 1 eine perspektivische Ansicht eines Ausführungsbeispiels einer Zerstäuberdüse,
• Figur 2 einen Längsschnitt entlang der Düsenachse durch das Ausführungsbeispiel der Zerstäuberdüse aus Figur 1 und
• Figur 3 eine schematische, blockschaltbildähnliche Prinzipdarstellung der erfindungsgemäßen Zerstäuberdüse.

Advantageous embodiments of the invention result from the dependent claims, the description and the drawing. Preferred exemplary embodiments of the invention are explained in detail below with reference to the attached drawing. Show it:

• Figure 1 2 shows a perspective view of an exemplary embodiment of an atomizing nozzle,
• Figure 2 a longitudinal section along the nozzle axis through the embodiment of the atomizer nozzle Figure 1 and
• Figure 3 is a schematic, block diagram-like schematic diagram of the atomizer nozzle according to the invention.

An atomizing nozzle 10 is illustrated in the drawing. The Figures 1 and 2nd show a preferred embodiment while Figure 3 illustrates the principle of operation.

The atomizer nozzle 10 is used on a mobile or stationary spray device and is used to atomize a supplied liquid F using compressed gas L and to deliver the finely atomized liquid particles as a spray jet S or spray mist. In the block diagram according to Figure 3 the flowing liquid F is schematically illustrated by block arrows and the compressed gas L by simple arrows. The point density schematically shows the fine atomization of the liquid F in Figure 3 illustrated, with a lower point density representing a finer atomization.

The atomizing nozzle 10 has a nozzle housing 11. A liquid connection 12 for supplying the liquid F and a gas connection 13 for supplying the compressed gas L are provided on the nozzle housing. The liquid connection 12 is arranged on a hollow cylindrical connection piece 14 of the nozzle housing 11. The connecting piece 14 is arranged coaxially to a nozzle axis A. The gas connection 13 is arranged, for example, in a ring around the connection piece 14 coaxially to the nozzle axis A. The number and the arrangement of the gas connection 13 and the liquid connection 12 can also be provided in a different arrangement and orientation on the nozzle housing 11, depending on the spray device on which the atomizing nozzle 10 is used.

In the exemplary embodiment shown here, the nozzle housing 11 has an approximately cylindrical contoured housing part 11a, from which the connecting piece 14 of the nozzle housing 11 protrudes. The housing part 11a is arranged coaxially to the nozzle axis A. The gas connection 13 is arranged coaxially around the connection piece 14 in an end wall of the housing part 11a. A tool engagement section 11b with one or more engagement surfaces for a tool can be provided on the housing part 11a, for example in order to rotate the atomizer nozzle 10 in the circumferential direction U when it is attached to a spray device and to connect it mechanically and fluidically to the spray device.

The nozzle housing 11 is designed, for example, as a one-piece, integral nozzle body 15 and can be produced, for example, as 3D printing or by another additive manufacturing process. The nozzle body 15 is free of seams and joints and is made of a uniform material.

The liquid connection 12 is fluidly connected to a liquid channel 19. A first section 19a of the liquid channel 19 adjoining the liquid connection 12 has a cylindrical shape and extends coaxially to the nozzle axis A. Immediately adjacent to the first section 19a is a swirl generating section 19b of the liquid channel 19. A swirl generator 20 is arranged in this swirl generating section 19b, which swirls the liquid F which flows from the first section 19a into the swirl generating section 19b. As a result of the swirl being imparted, the liquid F no longer flows in or after the swirl generator section 19b only axially along the liquid channel 19, but instead a hollow-cone-shaped jet course or, if appropriate, arises a spiral or helical flow pattern.

In the exemplary embodiment, the swirl generator 20 is formed by a swirl body 21 which is arranged coaxially to the nozzle axis A in the swirl generator section 19b. The swirl body 21 can have guide surfaces or guide channels in order to impart a swirl to the liquid F. It is also possible to use a swirl generator 20 with a paddle wheel.

In principle, one or more suitable swirl generating means can be used to impart a swirl to the liquid when it flows into the liquid channel 19 or while it is flowing in the liquid channel 19. Flow effects, such as the Coanda effect, can also be used to impart swirl. It is also possible to carry out the inflow of the liquid F into the liquid channel 19 radially offset to the nozzle axis A, tangential to a channel wall 22 of the liquid channel 19 and inclined at an angle to the nozzle axis A, so that a swirling liquid flow is already achieved thereby.

As a further possibility, a baffle body could also be arranged in the liquid channel 19 (not illustrated), which is suitable, for example, is essentially plate-shaped, so that when a liquid F impacts the baffle body, a thin, essentially plate-shaped liquid layer is generated, which is also referred to as an impact jet.

In the embodiment described here supports the swirl generation in the swirl generation section 19b in that the channel cross section of the swirl generation section 19b or a transition section immediately following downstream of the swirl generation section 19b and not specified here in the flow direction is reduced. This is achieved in that the diameter of the swirl generating section 19b or transition section decreases starting from the first section 19a. The swirl generation is preferably completed immediately before the transition section.

In a modified exemplary embodiment, the diameter of the liquid channel 19 in the swirl generation section 19b can be constant and the tapered transition section can be omitted, which is shown schematically in the basic illustration according to example Figure 3 is illustrated.

An end section 19c of the liquid channel 19 is optionally connected to the swirl generating section 19b via the transition section. In the end section 19c of the liquid channel 19, the diameter of the channel wall 22 increases away from the swirl generating section 19b. The liquid flowing along the channel wall 22 has a tendency to flow further along the channel wall 22, starting from the smallest channel wall diameter at the transition point between the swirl generating section 19b and the end section 19c. As a result, a flow layer FH of liquid F is formed in the end section, which has the shape of a truncated cone. The flow layer FH is formed coaxially to the nozzle axis A in the atomizing nozzle 10. The flow layer FH is highly schematized in Figure 3 illustrated by the block arrows and dots in the end portion 19c.

To further support the formation of the hollow-cone-shaped flow layer FH, a central part 25 is arranged in the end section 19c of the liquid channel, the diameter of which extends to an annular mixing chamber 26 into which the liquid channel 19 opens. According to the example, the ring mixing chamber 26 directly adjoins the end section 19c of the liquid channel 19.

The central part 25 is penetrated centrally by the nozzle axis A. Due to the arrangement of the central part 25 and the widening channel cross section of the end section 19c, the end section 19c is embodied as a hollow, frustoconical truncated cone, which is closed coaxially with the nozzle axis A, in the circumferential direction U around the nozzle axis A.

The channel wall 22 of the liquid channel 19 is curved in the swirl generating section 19b and the end section 19c along the nozzle axis A. The channel cross section is thereby reduced in the swirl generating section 19b and enlarged again in the end section 19c. Adapted to this, the outer surface 27 of the central part 25 is also curved along the nozzle axis A and, for example, is concavely curved. The outer surface 27 of the central part 25 lies opposite the channel wall 22 and is preferably adapted to the course of the channel wall such that the radial wall distance perpendicular to the nozzle axis A between the outer surface 27 of the central part 25 and the outer inner wall of the end section 19c remains essentially constant, wherein the annular flow cross-sectional area increases in the downstream direction with increasing distance from the nozzle axis A.

In the atomizer nozzle 10, a frustoconical flow layer FH is thus generated in front of the annular mixing chamber 26 and flows into the annular mixing chamber 26. For this purpose, a swirl generating means and / or the widening end section 19c with the central part 25 arranged therein can be used. For example, both measures are implemented together.

Compressed gas L is supplied in the annular mixing chamber 26 adjoining the end section 19c in order to atomize the liquid F into small liquid particles. For this purpose, the gas connection 13 is connected to a gas line system 28 of the atomizer nozzle 10. The gas line system 28 may include gas hoses that are arranged outside the nozzle housing 11, wherein — as in the preferred exemplary embodiment illustrated here — preferably only gas channels are used that are arranged or formed in the nozzle housing 11 and, for example, in the housing part 11a. In the exemplary embodiment, all gas channels of the gas line system 28 are formed during the manufacture of the nozzle body 15.

The gas line system 28 includes an outer injection channel 29 which extends in the circumferential direction U around the nozzle axis A in an annular manner around at least a section of the liquid channel 19 and opens into the ring mixing chamber 26 at an outer injection point 30. The outer injection point 30 is designed as an annular gap and is arranged coaxially to the nozzle axis A.

Radially outside opposite the ring mixing chamber 26 and, for example, coaxially with the ring mixing chamber 26, there is an annular connecting channel 31 in the exemplary embodiment Gas line system 28 arranged in the nozzle housing 11, which is fluidly connected via one or more through openings 32 to a central gas channel 33 of the gas line system 28. The central gas channel 33 extends along the nozzle axis A and is enclosed by the annular mixing chamber 26 in the circumferential direction U. A portion of the compressed gas L, which is fed to the central gas channel 33, opens into an inner injection channel 34 on the radially inner side of the ring mixing chamber 26. The inner injection channel 34 can be formed by a section of the central gas channel 33 or by partition walls separated from the central gas channel 33 branch off. The inner injection channel 34 opens into the annular mixing chamber 26 at an inner injection point 35. The inner injection point 35 is designed as an annular gap that is preferably closed in the circumferential direction U about the nozzle axis A and is as uninterrupted as possible.

In addition to the inner injection channel 34, a central channel 36 is fluidly connected to the central gas channel 33, which can branch off from the central gas channel 33 or can be formed by a section of the central gas channel 33. The central channel 36 opens into the liquid channel 19a upstream of the end section 19c. The mouth 37 of the central channel 36 is arranged coaxially to the nozzle axis A and oriented in the direction of the nozzle axis A away from the end section 19c or the annular mixing chamber 26. The pressure gas L flowing out there thus flows approximately counter to the liquid F and supports the formation of the flow layer FH in the end section 19 c of the liquid channel 19.

At the end of the atomizing nozzle 10, at which at least one spray jet S is emitted, there is at least one outlet opening 40. The one here in the Figures 1 and 2nd illustrated preferred embodiment, the atomizer nozzle 10 has a plurality, for example 8, of outlet openings 40 arranged distributed in the circumferential direction U around the nozzle axis A. The at least one outlet opening 40 can be designed as a cylindrical bore, as a slot or preferably in the form of a Laval nozzle. According to the example, the at least one outlet opening 40 has a cross section which widens conically in the flow direction. The longitudinal axis of each outlet opening 40 is inclined with respect to the nozzle axis A. The angle of inclination of the bore axis of the outlet opening 40 to the nozzle axis A is preferably in the range between 10 ° and 30 °. A spray jet S is generated through the plurality of outlet openings 40 and is directed away from the nozzle axis A ( Figures 1 and 3rd ).

The outlet openings 40 are arranged in pipe sections 41 which are fluidly connected to the annular mixing chamber 26. The through openings 32 are formed between the pipe pieces 41 in that pipe pieces 41 which are directly adjacent in the circumferential direction U are arranged at a distance from one another. A fluidic connection between the connecting channel 31 and the central gas channel 33 is thereby formed between the pipe pieces 41.

Between the connecting channel 31 and the outer injection channel 29 there is a partition wall 45 which guides the gas flow in the outer injection channel 29 to the outer injection point 30. In the direction of the flow of the pressurized gas L there is at least one communication opening 46 in the partition 45 at a distance from the outer injection point 30, through which pressurized gas L can flow from the gas connection 13 into the connecting channel 31. Thus, both the outer injection channel 29 and the inner injection channel 34 are supplied with compressed gas L via the gas connection 13.

Via the communication opening 46, the volume flows in the connecting channel 31 to the central gas channel 33 and the inner injection point 35 on the one hand and through the outer injection channel 29 and the outer injection point 30 on the other hand are determined depending on requirements. In preferred embodiments, the ratio of the cross-sectional area of the communication opening 46 to that of the outer injection site 30 is, for example, in the range from approximately 20% to 40%, preferably approximately 30%.

If necessary, the cross sections in the gas line system 28 can be selected such that a larger gas volume flow flows into the annular mixing chamber 26 via the outer injection channel 29 and the outer injection point 30 than via the inner injection channel 34 or the inner injection point 35. The area ratio is exemplary predefined between the outer injection site 30 and the inner injection site 35 in a ratio of 1.5: 1 to 2.5: 1. In the preferred embodiment, the area ratio is approximately 2: 1. Then, for example, at least about two thirds of the gas flowing into the annular mixing chamber 26 can flow in via the outer injection point 30.

The area ratio between the inner injection site 35 and the mouth 37 of the central channel 36 is approximately 1:10 to 1:15 in the exemplary embodiment.

As in the Figures 2 and 3rd is illustrated, the Liquid F in the ring mixing chamber 26 at the two injection points 30, 35 pressurized gas L. In Figure 2 schematically illustrates a center plane E of the ring mixing chamber 26, which essentially also corresponds to the center of the liquid jet in the ring mixing chamber 26. The central liquid jet entering the annular mixing chamber 26 from the end section 19c is indicated by a dotted line. In the direction of extension of the ring mixing chamber 26 along the central plane E through the ring mixing chamber 26, the two injection points 30, 35 are arranged offset to one another. According to the example, the compressed gas L, which flows out of the inner injection point 35, first strikes the flowing liquid F or the flow layer FH, while the compressed gas L flows out of the outer injection point 30 further downstream into the ring mixing chamber 26. In Figure 2 the first main outflow direction P1 from the outer injection channel 29 into the annular mixing chamber 26 is schematically illustrated by the first arrow. This first main outflow direction P1, which here runs approximately parallel to the nozzle axis A, for example, intersects the central liquid jet at a first angle α. Correspondingly, a second main outflow direction P2 for the compressed gas L from the inner injection channel 34 is drawn in by a second arrow, which is arranged at an acute angle to the nozzle axis A and forms a second angle β with the central liquid jet. For example, the amount of the second angle β is larger than the first angle α. The first angle α is in particular less than 45 °, while the second angle β is between 70 ° and 90 °.

The atomizing nozzle 10 according to the present invention works as follows:
A liquid F flows through the liquid channel 19. A swirl is imparted to the liquid flow in the swirl generating section 19b via a swirl generating means and, for example, the swirl generator 20. As a result of this and / or due to the pressure gas flowing in from the central channel 26 via the mouth 27 through the central part 25 and / or due to the diameter of the end section 19c of the liquid channel 19 widening towards the ring mixing chamber 26, a frustoconical flow layer FH is generated there, which flows into the ring mixing chamber 26 flows.

In the ring mixing chamber 26, compressed gas L first strikes the flow layer FH at the inner injection point 35 and influences its flow direction by giving the liquid flow in the flow layer FH an additional transverse component away from the nozzle axis A to the radially outer side of the ring mixing chamber 26. Compressed gas L is supplied somewhat downstream at the outer injection point 30. Because the liquid flow has already been stimulated upstream at the inner injection point 35, very fine atomization of the liquid can be achieved by the inflow of the compressed gas L from the outer side of the annular mixing chamber. The pressurized gas L flowing into the ring mixing chamber from different sides creates a shearing effect, so to speak.

In the further course of the annular mixing chamber 26 downstream of the two injection points 30, 35, one or more curvatures extend the annular mixing chamber 26 towards the nozzle axis A and / or away from the nozzle axis A. a further atomization and uniform distribution of the liquid particles in the liquid-gas mixture can be achieved, which is then released through the outlet openings 40 in the form of spray jets S. According to the example, the annular mixing chamber 26 curves downstream of the two injection points first towards the nozzle axis A and then again away from the nozzle axis A.

Instead of a curved course of the annular mixing chamber 26 between the injection points 30, 35 and the outlet openings 40, a hollow-cylindrical design of the annular mixing chamber can also be provided in this section in a modification of the exemplary embodiment illustrated here.

The invention relates to an atomizing nozzle 10 with a liquid channel 19, to which an annular mixing chamber 26 is fluidly connected downstream. A liquid F is fed to the liquid channel 19 via a liquid connection 12. The atomizer nozzle 10 also has a gas connection 13 which is connected to a gas line system 28. Compressed gas L is conducted via this to an outer injection channel 29 and an inner injection channel 34. The two injection channels 29, 34 each open into the annular mixing chamber 26 at one injection point 30, 35. The outer injection point 30 is present on the radially outer mixing chamber wall with respect to a nozzle axis A, about which the ring mixing chamber 26 extends coaxially, and the inner injection point 35 on the radially inner mixing chamber wall. The inflowing liquid can be finely atomized with a low pressure gas consumption in the ring mixing chamber 26 and downstream of the ring mixing chamber 26 via at least one outlet opening 40 each as a spray jet S are delivered.

Reference symbol list:

10th

Atomizer nozzle

11

Nozzle housing

11a

Housing part

11b

Tool attack section

12th

Liquid connection

13

Gas connection

14

Connecting piece

15

Nozzle body

19th

Liquid channel

19a

first section of the liquid channel

19b

Swirl generating section

19c

End section

20th

Swirl generator

21

Swirl body

22

Channel wall of the liquid channel

25th

Central part

26

Ring mixing chamber

27

Outer surface of the central part

28

Gas pipe system

29

outer injection channel

30th

outer injection site

31

Connecting channel

32

Through opening

33

central gas channel

34

inner injection channel

35

internal injection site

36

Central channel

37

Mouth of the central channel

40

Outlet opening

41

Pipe piece

45

partition wall

46

Communication opening

α

first angle

β

second angle

A

Nozzle axis

E

Middle plane

F

liquid

FH

Flow layer

L

Compressed gas

P1

first outflow direction

P2

second outflow direction

S

Spray jet

U

Circumferential direction

Claims (14)

1. Atomizer nozzle (10) comprising
   a liquid connection (12) for supplying a liquid (F) to a liquid channel (19) that is connected downstream to an annular mixing chamber (26) that coaxially encloses a nozzle axis (A),
   a means (20, 25) that forms, in an end section (19c) of the liquid channel (19) widening to the annular mixing chamber (26), a widening flow layer (FH) directed obliquely away from the nozzle axis (A), said flow layer flowing into the annular mixing chamber (26) adjoining the end section (19c) of the liquid channel (19),
   at least one gas connection (13) for supplying pressurized gas (L) to a gas line system (28) that comprises at least one outer injection channel (29) and at least one inner injection channel (34),
   wherein the outer injection channel (29) opens into the annular mixing chamber (26) at an outer injection point (30) at a radially outside location relative to the nozzle axis (A),
   and wherein the inner injection channel (34) opens into the annular mixing chamber (26) at an inner injection point (35) at a radially inside location relative to the nozzle axis (A),
   characterized in that
   the means (20, 25) for generating the flow layer (FH) comprises a swirl-generating means (20, 21) that imparts a swirl to the liquid (F) flowing in the liquid channel (19) .
2. Atomizer nozzle according to Claim 1, characterized in that the outer injection point (30) and the inner injection point (35) are arranged so as to be offset relative to each other in an extension direction of the annular mixing chamber (26).
3. Atomizer nozzle according to Claim 2, characterized in that the outer injection point (30) is arranged in the extension direction of the annular mixing chamber (26) downstream relative to the inner injection point (35).
4. Atomizer nozzle according to anyone of the preceding claims, characterized in that the gas line system (28) fluidically connects the inner injection channel (34) and the outer injection channel (30) to the gas connection (13) and is configured such that the gas volume flow flowing into the annular mixing chamber (26) via the outer injection channel (29) is greater than the gas volume flow flowing into the annular mixing chamber (26) via the inner injection channel (34), and/or that the cross-sectional area of the outer injection point (30) is larger than that of the inner injection point (35).
5. Atomizer nozzle according to anyone of the preceding claims, characterized in that the annular mixing chamber (26) is connected downstream to at least one outlet opening (40) from which the atomized spray jet (S) is discharged.
6. Atomizer nozzle according to Claim 5, characterized in that the annular mixing chamber (26) has a shape that is curved in the direction of the nozzle axis (A) one or more times between the injection points (30, 35) and the at least one outlet opening (4).
7. Atomizer nozzle according to anyone of the preceding claims, characterized in that the means (20, 25) for generating the flow layer (FH) is arranged to generate a flow layer (FH) that is closed in circumferential direction (U) around the nozzle axis (A).
8. Atomizer nozzle according to anyone of the preceding claims, characterized in that the means (20, 25) for generating the flow layer (FH) has a central part (25) arranged in or upstream of the end section (19c) of the liquid channel (19), said flow layer (FH) flowing around said central part, wherein the nozzle axis (A) extends through the central part (25).
9. Atomizer nozzle according to anyone of the preceding claims, characterized in that the swirl-generating means comprises a swirl generator (20) which is arranged in the fluid channel (19) and which is acted upon by the inflowing liquid (F) and imparts a swirl to said liquid flow.
10. Atomizer nozzle according to Claim 9, characterized in that the swirl generator (20) is arranged in a swirl-generating section (19b) of the liquid channel (19) adjoining the end section (19c) of the liquid channel (19) upstream thereof.
11. Atomizer nozzle according to anyone of the Claims 9 to 10, characterized in that the swirl-generating means comprises a swirl-generating section (19c) of the liquid channel (19) adjoining the end section (19c) of the liquid channel (19) upstream thereof, said end section (19c) forming a section, or being arranged directly upstream of a section, that has a cross-section or diameter that decreases toward the end section (19c).
12. Atomizer nozzle according to anyone of the preceding claims, characterized in that the gas line system (28) comprises a central channel (33) that extends in the central part (25) along the nozzle axis (A) and opens into the liquid channel (19).
13. Atomizer nozzle according to anyone of the preceding claims, characterized in that the atomizer nozzle (10) comprises a nozzle body (15) in which the liquid channel (19) and the annular mixing chamber (26) are provided, said nozzle body being integrally formed.
14. Atomizer nozzle according to Claim 13, characterized in that the central part (25) is an integral part of the nozzle body (15).

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