EP3804861A1 - Spray device and injection nozzle for a spray device - Google Patents

Abstract

The invention relates to an injection nozzle for a spray device for sucking in a liquid suction medium by means of a pressurized liquid propellant medium and for spraying a mixture of the suction medium and the propellant medium, with a nozzle housing, with an injection chamber arranged in the nozzle housing, a propulsion nozzle opening into the injection chamber for generating a jet of propellant medium entering the injection chamber, a liquid suction opening for the liquid suction medium, in which the liquid suction opening opens into an annular channel which has a flow connection to the injection chamber.

Description

The invention relates to an injection nozzle for a, in particular agricultural, spray device for sucking in a liquid suction medium by means of a liquid propellant medium under excess pressure and for spraying a mixture of the suction medium and the propellant medium, with a nozzle housing, with an injection chamber arranged in the nozzle housing, an in the propellant nozzle opening into the injection chamber for generating a propellant medium jet entering the injection chamber and a liquid suction opening for the liquid suction medium. The invention also relates to a spray device, in particular for agricultural purposes, for spraying a mixture of a liquid suction medium and a liquid propellant medium.

The invention aims to improve an injection nozzle and a spray device.

According to the invention, an injection nozzle with the features of claim 1 and a spray device with the features of claim 18 are provided for this purpose. Advantageous further developments of the invention are specified in the subclaims.

The injection nozzle according to the invention for a spray device is provided for sucking in a liquid suction medium by means of a liquid propellant medium under excess pressure and for spraying a mixture of the suction medium and the propellant medium. The injection nozzle has a nozzle housing, an injection chamber arranged in the nozzle housing, a propellant nozzle opening into the injection chamber for generating a propellant medium jet entering the injection chamber and a liquid suction opening for the liquid suction medium. The liquid suction opening opens into an annular channel which has a flow connection to the injection chamber.

Injection nozzles are known in principle and work according to the so-called Venturi principle. A jet of liquid enters an injection chamber, creates a negative pressure in the injection chamber and then carries gas or air with it. The so-called water jet pump works according to this principle.

In the field of plant protection, conventional injection nozzles are problematic because the mixing ratio between the liquid that is sucked in and the carrier liquid changes greatly with the pressure or the amount of the carrier liquid. Such a change in the mixing ratio, even only in the event of unintentional fluctuations in pressure Carrier liquid, but is extremely problematic in agricultural engineering. The injection nozzle according to the invention can ensure an essentially constant mixing ratio between the propellant and the suction medium even when the pressure of the propellant supplied changes.

Since the liquid suction medium first enters an annular channel which has a flow connection to the injection chamber, an even distribution of the suction medium can be ensured first in the annular channel and then also when it enters the injection chamber. The annular channel can surround the propellant nozzle. The flow connection from the annular channel to the injection chamber can be formed by means of a plurality of through bores arranged on an imaginary concentric circle or in some other suitable manner. It is advantageous if the suction medium enters the injection chamber in such a way that it evenly surrounds the propellant jet emerging from the propellant nozzle.

In a further development of the invention, the annular channel to the injection chamber is open on one side, so that the flow connection to the injection chamber is formed by means of an annular gap.

In this way, the suction medium can enter the injection chamber in the form of an annular jet, so that a uniform mixing between the propellant medium and the suction medium can be ensured in the injection chamber. The jet of propellant which opens into the injection chamber generates a negative pressure which acts in an area surrounding the jet of propellant. When the suction medium enters the injection chamber through an annular gap, the suction medium is sucked in evenly over the circumference of the injection chamber.

In a further development of the invention, the liquid suction opening opens into the annular channel upstream of the outlet opening of the propellant nozzle.

As a result, the suction medium in the annular channel can initially be distributed evenly over the circumference of the annular channel, so that the suction medium then enters the injection chamber evenly distributed around the circumference of the propellant jet via the flow connection to the injection chamber.

In a further development of the invention, the flow connection from the annular channel to the injection chamber opens into the injection chamber at the level of the outlet opening of the propellant nozzle.

Immediately after the jet of propellant medium emerges from the outlet opening of the propellant nozzle into the injection chamber, there is a comparatively large negative pressure. Since the flow connection from the annular channel to the injection chamber opens into the injection chamber at the level of the outlet opening of the propellant nozzle, a good, even suction effect can be achieved.

In a further development of the invention, the annular channel is delimited at least on one side by a driving nozzle housing of the driving nozzle.

The suction medium flows in the annular channel around a propulsion nozzle housing and then enters the injection chamber as an annular jet, radially surrounding the propulsion nozzle housing. In this way, a very even volume distribution of the suction medium around the propellant medium jet can be achieved and a structurally comparatively simple construction of the injection nozzle can be ensured, since the propellant nozzle housing simultaneously serves as a one-sided delimitation of the annular channel.

In a further development of the invention, at least one screen is provided in a suction channel upstream of the liquid suction opening.

By means of such a diaphragm or such a restrictor or also several diaphragms or restrictors arranged one behind the other, an amount of the incoming suction medium can be controlled and a constant ratio between the amount of the propellant medium and the amount of the suction medium can be ensured even with pressure fluctuations of the propellant medium. For example, two orifices arranged one behind the other in the direction of flow can be provided in the intake duct. The aperture openings of the apertures or restrictors do not necessarily have to be arranged in alignment with one another, but can also be offset from one another.

In a further development of the invention, the nozzle housing is provided with a diaphragm insert which has a section of the suction channel for sucking in the liquid suction medium and the diaphragm and which is detachably arranged on the nozzle housing.

By providing a diaphragm insert detachably arranged on the nozzle housing, the injection nozzle according to the invention can be constructed in a modular manner. Depending on the desired ratio between the propellant medium and the suction medium, the passage opening of the diaphragm can be changed by inserting a diaphragm insert with a different diaphragm. If a mixture of pesticides and water is to be produced, can Replacing the panel insert therefore changes the concentration of the crop protection agent in the water. Depending on the requirements placed on the mixing ratio between pesticides and water, generally between suction medium and propellant medium, the restrictor bore, in other words the aperture, can have a diameter between, for example, 0.1 mm to 1.5 mm.

In a further development of the invention, the diaphragm insert is connected to the nozzle housing by means of a sliding guide. In this way, the diaphragm insert can be connected to the nozzle housing in a very simple manner. For example, the diaphragm insert has a connecting piece which can be pushed into a suitable bore in the nozzle housing. The connecting piece can be provided with a circumferential sealing ring in order to completely form the intake duct by simply pushing in the diaphragm insert and to seal it off from the environment. Of course, it is also possible for the nozzle housing to have a connecting piece and the diaphragm insert to have a receiving area. The diaphragm insert can be pushed into the nozzle housing by means of the sliding guide and locks automatically in its end position, for example by locking sealing rings into suitable grooves or receptacles on the nozzle housing. To release the diaphragm insert, for example, a small recess can be provided between the nozzle housing and the diaphragm insert, into which the blade of a screwdriver can be inserted. By simply turning the screwdriver, the panel insert is then moved a little way in the direction of extension along the sliding guide counter to the direction of insertion. This movement caused by the rotation of the screwdriver is then sufficient to release the locking between the diaphragm insert and the nozzle housing. After this latching has been released, the panel insert can simply be pulled out of the sliding guide by hand and without the need for additional tools.

In a further development of the invention, the diaphragm insert is detachably arranged on an injector component that has at least the propellant nozzle and the injection chamber.

In this way, the modular structure of the injection nozzle according to the invention can be developed. For example, different injector components can be used for different suction media. Above all, the injector component with the propellant nozzle, which can wear out, can be exchanged in a simple manner. The injector component with the orifice insert attached to it is expediently inserted into an outlet nozzle component of the injection nozzle. The injector component can be removed from the outlet nozzle component and only then can the panel insert be detached from the injector component.

In a further development of the invention, the injection chamber has, downstream of the outlet opening of the propellant nozzle, a first conical section which widens in the direction of flow, and has a second conical section which adjoins the first conical section and which widens in the direction of flow, the second conical portion has a larger cone angle than the first conical portion.

With such a design of the injection chamber with two consecutive conical sections, a mixing ratio between propellant and suction medium can be kept essentially constant even in the event of pressure fluctuations in the propellant.

In a further development of the invention, a cone angle of the first conical section is in the range from 5 ° to 15 °, in particular between 5 ° and 10 °.

In a further development of the invention, a cone angle of the second conical section is in the range from 30 ° to 40 °.

In a further development of the invention, the first conical section, viewed in the direction of flow, has a length which is in the range of twice to four times, in particular three times, the length of the second conical section.

In a further development of the invention, an outlet opening of the propellant nozzle opens into a section of the injection chamber that tapers conically in the direction of flow.

Such a configuration of the injection chamber contributes to a uniform mixing ratio between the propellant medium and the suction medium even in the event of pressure fluctuations in the propellant medium.

In a further development of the invention, a cylindrical section of the injection chamber is arranged upstream of the first conical section, the first conical section adjoining the cylindrical section.

The provision of such a cylindrical section upstream of the two conical sections and in particular downstream of the conically tapering section also contributes to a constant mixing ratio between propellant and suction medium, even with pressure fluctuations in the propellant.

In a further development of the invention, a ratio between the diameter of the cylindrical section of the injection chamber and a length of the section of the injection chamber that tapers conically in the direction of flow between the outlet opening of the propellant nozzle and the beginning of the cylindrical section is in the range from 0.5 to 5, in particular between 1 and 2, especially at 1.4.

In a further development of the invention, a ratio between the diameter of the cylindrical section of the injection chamber and a diameter of the outlet opening of the propellant nozzle is in the range from 1 to 3, in particular between 1.5 and 1.7, in particular 1.6.

In a further development of the invention, a diaphragm is provided in a suction channel upstream of the liquid suction opening, with a ratio between the diameter of the cylindrical section of the injection chamber and a diameter of a passage opening of the diaphragm in the range from 1.5 to 15, in particular between 4 and 6, in particular at 4.7, lies.

In a further development of the invention, a ratio between an area of the cylindrical section of the injection chamber and an area of the flow connection from the annular channel to the injection chamber is in the range from 0.25 to 2.5, in particular between 0.5 and 1, in particular 0.76 .

In a further development of the invention, the flow connection between the annular channel and the injection chamber is arranged in a section immediately upstream of the opening into the injection chamber between two walls which taper conically in the direction of flow.

In this way, constant flow conditions and pressure conditions can be set over the circumference of the annular channel and over the circumference of the injection chamber. For example, the annular channel merges into the injection chamber by means of an annular gap. Since this annular gap between the annular channel and the injection chamber tapers conically in the direction of flow, a constant mixing ratio between the propellant and suction medium is contributed to, even in the event of pressure fluctuations in the propellant.

The problem on which the invention is based is also solved by means of a spray device for spraying a mixture of a liquid suction medium and a liquid propellant medium with an injection nozzle according to the invention.

Fig. 1

eine auseinandergezogene Darstellung einer erfindungsgemäßen Injektionsdüse,

Fig. 2

eine Schnittansicht der erfindungsgemäßen Injektionsdüse,

Fig. 3

eine vergrößerte Schnittansicht eines Injektorbauteils der erfindungsgemäßen Injektionsdüse,

Fig. 4

eine Ansicht eines erfindungsgemäßen Injektorbauteils gemäß einer weiteren Ausführungsform,

Fig. 5

einen Blendeneinsatz für das Injektorbauteil der Fig. 4,

Fig. 6

eine Schnittansicht des Blendeneinsatzes der Fig. 5 und

Fig. 7

das Injektorbauteil der Fig. 4 ohne den Blendeneinsatz.

Further features and advantages of the invention emerge from the claims and the following description of preferred embodiments of the invention in conjunction with the drawings. Individual features of the different illustrated or described embodiments can be combined in any way. This also applies to the combination of individual features without further individual features with which they are shown in connection. In the drawings show:

Fig. 1

an exploded view of an injection nozzle according to the invention,

Fig. 2

a sectional view of the injection nozzle according to the invention,

Fig. 3

an enlarged sectional view of an injector component of the injection nozzle according to the invention,

Fig. 4

a view of an injector component according to the invention according to a further embodiment,

Fig. 5

a panel insert for the injector component of the Fig. 4 ,

Fig. 6

a sectional view of the diaphragm insert of FIG Fig. 5 and

Fig. 7

the injector component of the Fig. 4 without the bezel insert.

Fig. 1 shows an injection nozzle 10 according to the invention in the extended state. The injection nozzle 10 has an injector component 12 and an outlet nozzle component 14. The injector component 12 is inserted into the outlet nozzle component 14 in sections, cf. Fig. 2 to achieve an operable state of the injector nozzle 12. The injection nozzle 12 is then inserted in a known manner into a nozzle holder (not shown) of a spray device, in particular an agricultural spray device.

A screen 16 can be seen on the injector component 12 which marks the beginning of an intake duct in the injector component 12. Liquid suction medium is sucked in from a storage tank via the diaphragm 16, mixed with a liquid propellant medium and a mixture of suction medium and propellant medium is dispensed at a downstream end 18 of an injection chamber. The mixture then enters the outlet nozzle component 14, cf. Fig. 2 , and is output as a flat jet via an outlet opening 20 of a flat jet nozzle 22. Instead of the flat jet nozzle 22, a substantially any outlet nozzle can be provided on the outlet nozzle component 14, for example a hollow cone nozzle or a full cone nozzle.

Fig. 2 FIG. 10 shows a sectional view of the injection nozzle 10 of FIG Fig. 1 when assembled. The injector component 12 has now been inserted into the outlet nozzle component 14 in sections. At the end 18 of an injection chamber 24, a mixture of liquid suction medium and liquid propellant medium enters an outlet chamber 26, at the downstream end of which the outlet nozzle 22 is then arranged.

A propellant nozzle housing 28 is arranged in the injector component, via which the liquid propellant medium, usually water under pressure, is introduced into the injection chamber 24 in the form of a propellant medium jet. In the embodiment shown, the jet of propellant medium is designed as a full jet and enters the injection chamber 24 via an outlet opening 30 of the propellant nozzle housing 28. The outlet opening 30 has a diameter d _TR .

The drive nozzle housing 28 is surrounded by an annular channel 32. A suction channel 34 opens into the annular channel 32 at a liquid suction opening 36 Fig. 2 the left end of the intake duct 34 is shown in FIG Fig. 2 limited by the aperture 16. The diaphragm 16 has a through opening 38 with a diameter d _R.

The annular channel 32 is delimited on one side by the driving nozzle housing 28 and is in flow connection with the injection chamber 24. In the embodiment shown, the flow connection between the annular channel 32 and the injection chamber 24 is in the form of an annular gap 40. The annular gap 40 is realized in that the annular channel 32 to the injection chamber 24 is open on one side. A surface of the annular gap 40 at the level of the downstream end of the outlet opening 30 is denoted _{by A S.} In the context of the invention, the flow connection between the annular channel 32 and the injection chamber 24 can also be designed differently, for example by means of several channels.

The injection chamber 24 has four sections viewed in the direction of flow.

The outlet opening 30 of the propellant nozzle 28 and the annular gap 40 open into a conically tapering section 42 of the injection chamber which is generally frustoconical. A cylindrical section 44 adjoins the conically tapering section 42. A first, conically widening section 46, which has a first cone angle, adjoins the cylindrical section 44. At the first Conically widening section 46 is followed by a second conically widening section 48 which has a second cone angle. The second cone angle is larger than the first cone angle. The first conically widening section 46 is longer than the second conically widening section 48. A cone angle of the first conical section is in the range between 5 ° and 15 ° and in particular between 5 ° and 10 °. A cone angle of the second conical section 48 is in the range from 30 ° to 40 °. The first conical section 46, viewed in the direction of flow, has a length which is in the range of twice to four times, in particular three times, the length of the second conical section 48. The two successive, conically widening sections 46, 48 contribute to a constant mixing ratio between the liquid propellant medium and the liquid suction medium even in the event of pressure fluctuations in the propellant medium.

A jet of propellant medium generated by means of the propellant nozzle and exiting from the outlet opening 30 of the propellant nozzle housing 28 enters the conically tapering section 42 of the injection chamber 24 and generates a negative pressure in the injection chamber 24 by means of the so-called Venturi effect 38 of the diaphragm 16 is sucked into the suction channel 34 and enters the annular channel 32 via the liquid suction opening 36. The suction medium is distributed in the annular channel 32 and then enters the injection chamber 24 through the annular gap 40, evenly distributed over the circumference of the drive nozzle housing 28. Instead of the annular gap 40, for example, several through channels can also be provided between the annular channel 32 and the injection chamber 24.

The jet of propellant medium, together with the sucked-in suction medium, enters the cylindrical section 44 and then into the two conically widening sections 46, 48 of the injection chamber 24. Already in the conically tapering section 42 of the injection chamber 24, the propellant jet begins to tear open and the propellant jet and the sucked-in suction medium are mixed. As a result, at the downstream end 18 of the injection chamber 24, a mixture of suction medium and propellant medium enters the outlet chamber 26. In the outlet chamber, the mixture between the propellant and the suction medium is made more uniform. In the embodiment shown, a flat jet consisting of a mixture between propellant and suction medium then emerges from the outlet nozzle 22. As stated, the special design of the injection nozzle 10 ensures a constant mixing ratio between propellant and suction medium, even in the event of pressure fluctuations in the propellant. The injection nozzle 10 according to the invention is thereby particularly suitable for use in agricultural engineering. The outlet nozzle 22 can also be designed as a full cone nozzle or a hollow cone nozzle within the scope of the invention.

Fig. 3 FIG. 11 shows an enlarged illustration of the injector component 12 of the injection nozzle 10 of FIG Figs. 1 and 2 .

A diameter of the through opening of the diaphragm 16 is denoted _{by d R.} A diameter of the outlet opening 44 of the driving nozzle housing 28 is denoted _{by d TR.} A length of the conically tapering section 42 of the injection chamber 24 is designated by h seen in the flow direction. A diameter of the cylindrical section 44 of the injection chamber 24 is _{denoted by d DH} and a cross-sectional area of the cylindrical section 44 is denoted _{by A DH.}

A surface of the annular gap 40 at the downstream end of the flow connection between the annular channel 32 and the injection chamber 24 is denoted _{by A S.} A cone angle of the first conically widening section 46 of the injection chamber 24 is denoted by α1 and a cone angle of the second conically widening section 48 of the injection chamber 24 is denoted by α2. A length of the cylindrical section 44 of the injection chamber 24 is denoted _{by L 0.} A length of the first, conically widening section 46 is denoted _{by L 1} and a length of the second, conically widening section 48 is _{denoted by L 2.}

L ₀ is significantly smaller than h and in the embodiment shown is only about a third of h. L ₁ and L ₂ are much larger than L ₀ . L ₁ is larger than L ₂ and L ₁ is about twice as large to four times as large as L ₂ . α1 is in the range from 5 ° to 15 °, in particular between 5 ° and 10 °. α2 is in the range from 30 ° to 40 °.

A ratio d _DH / h between the diameter d _{DH of} the cylindrical section 44 of the injection chamber 24 and the length h of the section 42 of the injection chamber 24 which tapers conically in the direction of flow between the outlet opening 30 and the beginning of the cylindrical section 44 is in the range of 0, 5 to 5, in particular between 1 and 2, in particular at 1.4.

A ratio d _DH / d _TR between the diameter d _{DH of} the cylindrical section 44 of the injection chamber and a diameter d _{TR of} the outlet opening 30 of the propellant nozzle is in the range from 1 to 3, in particular between 1.5 and 1.7, in particular 1, 6th

A ratio d _DH / d _R between the diameter d _{DH of} the cylindrical section 44 of the injection chamber 24 and a diameter d _{R of} a through opening of the diaphragm 16 is in the range from 1.5 to 15, in particular between 4 and 6, in particular 4.7 .

A ratio A _DH / A _S between an area A _{DH of} the cylindrical section 44 of the injection chamber 24 and an area A _{S of} the flow connection from the annular channel 32 to the injection chamber 24, especially an area A _{S of} the annular gap 40, is in the range of 0, 25 to 2.5, in particular between 0.5 and 1, in particular at 0.76.

The ratios explained above and also the lengths and diameters and angles explained above contribute to a constant mixing ratio between suction medium and propellant medium, even if pressure fluctuations of the propellant medium occur. The injection nozzle according to the invention is therefore particularly suitable for use in agricultural engineering.

Fig. 4 shows an injector component 112 according to a further embodiment of the invention. The injector component 112 is very similar to the injector component 12 of FIG Figs. 1 to 3 constructed so that identical elements are either not explained or given the same reference numerals. The injector component 112 can instead of the injector component 12 of Figs. 1 to 3 in the in the Figs. 1 to 3 outlet nozzle component 14 shown are used.

The injector component 112 has a modular panel insert 114. The diaphragm insert 114 has the diaphragm 16 and a portion of the intake duct. The intake passage then continues in the injector component 112.

Fig. 5 shows the diaphragm insert 114 obliquely from below and Fig. 6 the panel insert 114 in a sectional view. Based on Fig. 6 it can be seen that the orifice insert 114 defines a portion 34A of the intake duct. The remaining section 34B of the intake duct, which then leads to the annular duct around the propellant nozzle, cf. Fig. 2 , on the other hand, is formed in the injector component 112.

At its upstream end of the intake channel 34A, the orifice insert 114 has the orifice 16 which defines the restrictor bore 38. Depending on the flow resistance of the restrictor bore 38, i.e. depending on the diameter of the restrictor bore 38 and the length of the restrictor bore 38, the flow resistance of the restrictor bore 38 changes and thus a ratio between the amount of suction medium sucked in and the amount of propellant medium can be set.

In Fig. 5 it can be seen that the section 34A of the intake duct is formed at its downstream end by means of a connecting piece 116 which protrudes beyond a stop surface 118 of the panel insert 114. The connector 116 is provided for this, cf. Fig. 7 to be pushed into a suitable recess 120 in the injector component 112. By simply pushing the panel insert 114 into the sliding guide of the injector component 112, with the pin 116 penetrating the recess 120 at the end of the sliding movement, on the one hand the section 34A is tightly connected to the section 34B of the intake duct. This is achieved in that the connecting piece 116 is provided with a circumferential projection 122 which can snap into a matching circumferential groove 124 in the recess 120. For example, the circumferential projection 122 is formed by means of a sealing ring, so that after the projection 122 has latched into the groove 124, the two sections 34A, 34B of the intake duct are tightly connected to one another. Only minor requirements are placed on the tightness of this connection, since the suction channel 34 and thus also the connection of the sections 34A, 34B are under negative pressure when the injection nozzle is in operation.

The projection 122, which is latched into the groove 124 in the assembled state of the diaphragm insert 114, also ensures that the diaphragm insert 114 is mechanically secured to the injector component 112.

The sliding guide is formed on the injector component 112 by means of two strip-shaped projections 126 which protrude into a recess on the injector component 112 which extends to the edge of the injector component. As a result, an undercut is formed between the strip-shaped projections 126 and a base 128 of the recess on both sides.

The panel insert 114 also has strip-shaped projections 130 on both sides, which are matched to the length, height and width of the undercut in the recess. By simply pushing the strip-shaped projections 130 into the undercuts on the injector component 112, the panel insert is thereby guided on the injector component 112. The panel insert 114 can be pushed into the injector component 112 along the sliding guide until the end face 118 of the panel insert 114 strikes the front boundary 132 of the recess in the injector component 112. This state is in Fig. 4 shown. As soon as the bezel insert 114 is in Fig. 4 has reached the end position shown, the projection 122 on the connection piece 116 of the panel insert 114 is also locked into the groove 124 in the recess 120 of the injector component 112.

In order to be able to change the panel insert 114, i.e. from the in Fig. 4 To remove the position shown, the edge of a coin or the blade of a screwdriver is in a rectangular recess 134 is introduced on the upper side of the injector component 112. The front face 118 of the diaphragm insert 114 forms a boundary of this recess 134. By turning the coin or the blade of the screwdriver, the diaphragm insert 114 can be moved a little way along the sliding guide in the radial direction away from the injector component 112. This movement only has to take place until the circumferential projection 122 on the connection piece 116 of the diaphragm insert 114 has been moved out of the groove 124 of the recess 120 in the injector component 112. The latching connection between the diaphragm insert 114 and the injector component 112 is thereby released. The panel insert 114 can then easily be removed from the injector component 112 by hand along the sliding guide. The diaphragm insert 114 can then be exchanged for another diaphragm insert, for example, which differs from the diaphragm insert 114 only by a different dimension of the restrictor bore 38 of the diaphragm 16. In this way, the injection nozzle according to the invention can be adapted in a simple manner in such a way that different ratios of the amount of suction medium and the amount of propellant medium can be set.

Claims (21)

Injection nozzle for a spray device for sucking in a liquid suction medium by means of a pressurized liquid propellant medium and for spraying a mixture of the suction medium and the propellant medium, with a nozzle housing, with an injection chamber arranged in the nozzle housing, a propulsion nozzle opening into the injection chamber for generating an in the propellant jet entering the injection chamber, a liquid suction opening for the liquid suction medium, characterized in that the liquid suction opening opens into an annular channel which has a flow connection to the injection chamber. Injection nozzle according to Claim 1, characterized in that the annular channel to the injection chamber is open on one side, so that the flow connection to the injection chamber is formed by means of an annular gap. Injection nozzle according to Claim 1 or 2, characterized in that the liquid suction opening opens into the annular channel upstream of the outlet opening of the propellant nozzle. Injection nozzle according to at least one of the preceding claims, characterized in that the flow connection from the annular channel to the injection chamber opens into the injection chamber at the level of the outlet opening of the propellant nozzle. Injection nozzle according to one of the preceding claims, characterized in that the annular channel is delimited at least on one side by a drive nozzle housing of the drive nozzle. Injection nozzle according to at least one of the preceding claims, characterized in that at least one screen is provided in a suction channel upstream of the liquid suction opening. Injection nozzle according to claim 6, characterized in that the nozzle housing is provided with a diaphragm insert which has a section of the suction channel for sucking in the liquid suction medium and the diaphragm and which is detachably arranged on the nozzle housing. Injection nozzle according to Claim 7, characterized in that the diaphragm insert is connected to the nozzle housing by means of a sliding guide. Injection nozzle according to Claim 7 or 8, characterized in that the diaphragm insert is detachably arranged on an injector component which has at least the propellant nozzle and the injection chamber. Injection nozzle according to at least one of the preceding claims, characterized in that the injection chamber, downstream of the outlet opening of the propulsion nozzle, has a first, conical section which widens in the direction of flow, and a second conical section which adjoins the first conical section and which is in Expanded flow direction, wherein the second conical section has a larger cone angle than the first conical section. Injection nozzle according to Claim 10, characterized in that a cone angle of the first conical section is in the range from 5 degrees to 15 degrees, in particular between 5 degrees and 10 degrees. Injection nozzle according to Claim 10 or 11, characterized in that a cone angle of the second conical section is in the range from 30 degrees to 40 degrees. Injection nozzle according to claim 10, 11 or 12, characterized in that the first conical section, viewed in the direction of flow, has a length which is in the range of twice to four times, in particular three times, the length of the second conical section. Injection nozzle according to at least one of the preceding claims, characterized in that an outlet opening of the propulsion nozzle opens into a section of the injection chamber which tapers conically in the direction of flow. Injection nozzle according to at least one of the preceding claims, characterized in that a cylindrical section of the injection chamber is arranged upstream of the first conical section, the first conical section adjoining the cylindrical section. Injection nozzle according to claims 14 and 15, characterized in that a ratio (d _DH / h) between the diameter (d _DH ) of the cylindrical section of the injection chamber and a length (h) of the section of the injection chamber which tapers conically in the direction of flow between the outlet opening of the Driving nozzle and the beginning of the cylindrical section is in the range from 0.5 to 5, in particular between 1 and 2, in particular 1.4. Injection nozzle according to Claim 15 or 16, characterized in that a ratio (d _DH / d _TR ) between the diameter (d _DH ) of the cylindrical section of the injection chamber and a diameter (d _TR ) of the outlet opening of the propellant nozzle is in the range from 1 to 3, in particular between 1.5 and 1.7, in particular up to 1.6. Injection nozzle according to Claim 15, 16 or 17, characterized in that a diaphragm is provided in a suction channel upstream of the liquid outlet opening, a ratio (d _DH / d _TR ) between the diameter (d _DH ) of the cylindrical section of the injection chamber and a diameter ( d _TR ) of a passage opening of the diaphragm in the range from 1.5 to 15, in particular between 4 and 6, in particular 4.7. Injection nozzle according to one of claims 15 to 18, characterized in that a ratio (A _DH / A _S ) between an area (A _DH ) of the cylindrical section of the injection chamber and an area (A _S ) of the flow connection from the annular channel to the injection chamber in The range is from 0.25 to 2.5, in particular between 0.5 and 1, in particular 0.76. Injection nozzle according to at least one of the preceding claims, characterized in that the flow connection between the annular channel and the injection chamber is arranged in a section immediately upstream of the opening into the injection chamber between two walls which taper conically in the direction of flow. Spray device for spraying a mixture of a liquid suction medium and a liquid propellant medium, characterized by at least one injection nozzle according to one of the preceding claims.

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