FLAT JET NOZZLE

Description

[0001] The invention relates to a flat jet nozzle with a housing having a liquid inlet for liquid to be sprayed and an outlet opening.

[0002] German patent application DE 10 2004 001 222 A1 discloses a nozzle unit, particularly for a cooking appliance. The nozzle unit comprises a liquid inlet, a swirl chamber following the liquid inlet, which is concentric around a central longitudinal axis, and two outlet openings arranged concentrically to the central longitudinal axis of the swirl chamber. The two outlet openings are located on opposite sides of the swirl chamber and are each designed to generate a hollow cone jet. A further slot-shaped outlet opening is arranged opposite the liquid inlet and intersects the swirl chamber directly.

[0003] International Patent Application WO 2006 / 028403 A1 discloses a spray nozzle in which two supply channels for the liquid to be sprayed open into a slot-shaped outlet. Shortly before the feed channels open into the slot-shaped outlet, helical paths are provided on an inner wall of the feed channels. The two feed channels meet directly, and the helical paths are oriented in opposite directions, so that a liquid jet exiting the outlet from the first channel rotates in the opposite direction to the liquid jet entering the outlet from the other feed channel. The helical paths are located in an end section of the feed channels, this end section having the same diameter as upstream sections of the feed channel.

[0004] European patent EP 0 216 043 B1 discloses a spray nozzle for a hand-held spray gun for the targeted dispensing of a liquid or pasty, pressurized medium such as paint, varnish, or the like. In one embodiment of the nozzle, a cylindrical swirl chamber is provided, and an outlet opening is arranged concentrically to a central longitudinal axis of the swirl chamber. A solid cone or hollow cone jet will therefore emerge from the outlet opening.

[0005] A spray nozzle for generating a full cone or hollow cone jet is known from US patent application US 2005 / 0133628 A1. A projection extends into a cylindrical swirl chamber.

[0006] German utility model DE 202 19 052 U1 discloses a spray nozzle for applying a liquid coating material, in particular a liquid film. The spray nozzle is designed as a so-called tongue nozzle. A narrowing feed channel directs a jet of liquid onto a deflector plate, from which a flat jet is then deflected laterally.

[0007] From the international patent application WO 98 / 58746 A1, an arrangement with several flat jet nozzles arranged side by side is known.

[0008] A spray nozzle with a drip-stop valve is known from Chinese patent application CN 105537015 A.

[0009] The invention aims to improve a flat jet nozzle with regard to its susceptibility to clogging.

[0010] According to the invention, a flat jet nozzle with the features of claim 1 or claim 4 is provided for this purpose. A flat jet nozzle is provided with a housing having a liquid inlet for the liquid to be sprayed and an outlet opening, wherein a swirl chamber is provided in a flow path for the liquid to be sprayed between the liquid inlet and the outlet opening within the housing.

[0011] The swirl chamber in the flow path for the liquid to be sprayed sets the liquid into rotation, thereby creating flow resistance. This allows for large free flow cross-sections at low volume flows. Surprisingly, by providing a swirl chamber between the liquid inlet and the outlet of a flat jet nozzle, it becomes possible to select very large free flow cross-sections within the housing. This makes the flat jet nozzle according to the invention very resistant to clogging. Swirl chambers are known in hollow cone nozzles and solid cone nozzles for generating a hollow cone or solid cone spray. In principle, generating rotation of the liquid to be sprayed by means of a swirl chamber is counterproductive when producing a flat jet.A flat jet is a spray pattern with a very shallow depth and a spray angle of less than 180°. To generate a flat jet, the liquid being sprayed does not need to be set into rotation. Typically, slot-shaped outlet openings, tongues, or deflector plates are used, onto which a jet of the liquid being sprayed strikes. As explained, rotation of the liquid being sprayed is counterproductive when generating a flat jet. In the flat jet nozzle according to the invention, the swirl chamber is used as a vortex throttle to generate flow resistance and thus a pressure drop while simultaneously providing large free flow cross-sections. The flat jet nozzle according to the invention is therefore very resistant to clogging. A flow rate can be adjusted by changing the geometry, in particular the height and radius, of the swirl chamber.The swirl chamber can be subjected to both tangential and axial flow. With axial flow, a swirl element or insert is generally required inside the chamber to impart rotation to the fluid flowing through it. The swirl chamber can be cylindrical, but this is not a requirement.

[0012] According to the invention, at least one deflection of the flow path, in particular between 70° and 110°, in particular 90°, is provided in the flow path for the liquid to be sprayed downstream of the swirl chamber.

[0013] By deflecting the flow path, the rotation of the flow generated in the swirl chamber is reduced. This allows for the creation of a flat jet with a shallow jet depth, uniform liquid distribution, and uniform droplet size distribution. This is possible with the flat jet nozzle according to the invention, while simultaneously offering large free flow cross-sections compared to conventional flat jet nozzles.

[0014] As an alternative to a deflection, a straight channel can be arranged downstream, the geometry of which, in particular its length and diameter, is dimensioned such that the rotation of the flow is reduced. The flat jet nozzle is designed as a tongue nozzle, and a tongue is provided downstream of the outlet opening, onto which the fluid exiting the outlet opening impinges, with the tongue forming a deflection of the flow path.

[0015] A tongue-shaped nozzle allows for the creation of a flat spray pattern even at low nozzle operating pressure or low flow velocities of the sprayed medium. Depending on the velocity at which the liquid exits the nozzle and then strikes the tongue downstream, different droplet sizes can be produced.

[0016] According to the invention, the swirl chamber is formed concentrically around a central longitudinal axis and a swirl chamber inlet opens tangentially to an imaginary circle around the central longitudinal axis into the swirl chamber.

[0017] In a further development of the invention, the swirl chamber is designed concentrically around a central longitudinal axis and a swirl chamber outlet is arranged concentrically to the central longitudinal axis.

[0018] In a further development of the invention, a projection projecting into the swirl chamber is provided on an end face of the swirl chamber opposite the swirl chamber outlet.

[0019] Such a protrusion creates a uniform liquid distribution in the swirl chamber.

[0020] In a further development of the invention, the projection is conical and tapers towards the swirl chamber outlet.

[0021] The flow resistance of the swirl chamber can be influenced by shaping the projection.

[0022] In a further development of the invention, the swirl chamber has a cylindrical section and a conically tapered section, wherein the swirl chamber inlet opens into the cylindrical section and the swirl chamber outlet is arranged at the end of the conical section with a smaller diameter.

[0023] In a further development of the invention, the housing is designed in at least two parts, wherein a first section of the housing has the liquid inlet and a first section of the swirl chamber and a second section of the housing has a second section of the swirl chamber and the outlet opening.

[0024] In this way, the housing can be designed modularly. The first section of the swirl chamber and the liquid inlet can always be identical, even with different nozzles. The shape of the emitted spray jet, the amount of liquid dispensed, and the direction of the emitted flat jet are set or defined by the geometry of the second section of the housing.

[0025] In a further development of the invention, a drip-stop valve is provided directly upstream or directly downstream of the liquid inlet, which closes off a flow path when the pressure of the liquid to be sprayed falls below a predefined level and releases the flow path when the predefined pressure is exceeded.

[0026] By means of a drip-stop valve, not only can dripping be prevented in the nozzle according to the invention, but the liquid still present in the swirl chamber, in particular water, can be used to rinse the nozzle.

[0027] In a further development of the invention, a central axis of an emitted spray jet is arranged parallel or perpendicular to a flow direction in the liquid inlet.

[0028] As with a conventional flat jet nozzle, the direction of the emitted flat jet can be varied. For example, a tongue nozzle is used. The tongue geometry generates a flat jet, and the jet angle can be varied accordingly depending on the tongue geometry. The upstream throttle chamber creates flow resistance and thus reduces the flow pressure. Compared to a conventional flat jet nozzle with the same flow cross-sections, especially a tongue nozzle, the volume flow of the flat jet nozzle according to the invention can be reduced by approximately 50% to 70% at the same operating pressure. Consequently, with the same free flow cross-sections, significantly less liquid is dispensed via the flat jet, resulting in a nozzle that is hardly susceptible to clogging. Blockages in nozzles can be caused by impurities in the liquid to be sprayed, as well as by dirt or other contaminants.Deposits within the nozzle occur. The large free flow cross-sections of the flat jet nozzle according to the invention, compared to a conventional flat jet nozzle, enable very low susceptibility to clogging.

[0029] Furthermore, the swirling or rotational flow generated in the swirl chamber creates a vortex and suction effect, which flushes dirt out of the nozzle according to the invention.

[0030] Further features and advantages of the invention will become apparent from the claims and the following description of preferred embodiments of the invention in conjunction with the drawings. Individual features of the different illustrated and described embodiments can be combined in any way without exceeding the scope of the invention, as long as the combination is covered by the claims. This also applies to the combination of individual features without any other individual features with which they are shown or described. The drawings show: Fig. 1 a top view of a flat jet nozzle according to a first embodiment of the invention, Fig. 2 a view of the section plane AA in Fig. 1 , Fig. 3 a view of the section plane BB in Fig. 1 Fig. 4 a sectional view of a flat jet nozzle according to a second embodiment according to the invention, Fig. 5 a top view of a flat jet nozzle according to a third embodiment according to the invention, Fig. 6 a view of the flat jet nozzle of the Fig. 5 from below, Fig. 7 a view of the flat jet nozzle of the Fig. 5 From above, Fig. 8 a view of the flat jet nozzle of the Fig. 5 from the side, Fig. 9 a view of the section plane AA in Fig. 5 and Fig. 10 a view of the section plane BB in Fig. 5 .

[0031] Fig. 1 Figure 1 shows a top view of a flat jet nozzle 10 according to a first embodiment of the invention. The flat jet nozzle 10 has a housing 12. The housing 12 has a Fig. 1 The housing has an invisible liquid inlet and an equally invisible outlet. It is made of two parts, comprising a first section 14 and a second section 16, which is only partially visible. The second section 16 is visible in Fig. 1 only a tongue 18 can be seen, onto which the liquid to be sprayed strikes upstream of the outlet opening, and from which a [something] then [something] Fig. 1 The flat jet is only indicated schematically and with dashed lines.

[0032] Fig. 2 shows a view of the section plane AA in Fig. 1 The two sections 14 and 16 of the housing 12 of the flat jet nozzle 10 are visible. The first housing section 14 has a liquid inlet 20, which is shown in the view of the Fig. 2 However, it is not cut in the middle, but at its edge. The housing 14 is provided with the first sections 22 of a bayonet fitting, with which the liquid inlet 20 can then be connected to a suitable pipe connection for supplying the liquid to be sprayed.

[0033] Starting from the liquid inlet 20, the liquid to be sprayed enters a swirl chamber 24 via an inlet channel, see Fig. 3 The liquid to be sprayed enters the swirl chamber 24 at an opening 26 of the inlet channel, tangentially to an imaginary circle around a central longitudinal axis of the swirl chamber 24. The swirl chamber 24 has a cylindrical section 28 and a conically tapered section 26. An outlet from the swirl chamber is provided at the end of the smaller-diameter conical section 26. The outlet of the swirl chamber causes a 90° deflection of the flow path, which then leads to an outlet opening 30. The tongue 18 is arranged downstream of the outlet opening 30. A jet exiting the outlet opening 30, which emerges essentially as a cylindrical solid jet, strikes the tongue 18 and is deflected by approximately 90° by the tongue 18. This deflects the fluid in the swirl chamber. Fig. 2 A flat jet is produced, indicated by a dashed line.

[0034] It is Fig. 2 It can be seen that the flat jet produced by the flat jet nozzle 10 exits at an angle of slightly more than 90° to a supply direction of the liquid to be sprayed in the liquid inlet 20.

[0035] A conical projection 32 extends into the cylindrical section 28 of the swirl chamber 24 from an end wall opposite the outlet. The conical projection 32 tapers towards the outlet and terminates within the cylindrical section 28. This projection ensures a uniform distribution of the fluid within the swirl chamber 24. The flow resistance of the swirl chamber 24, and thus the flow rate through it (which acts as a vortex restrictor), can be adjusted by modifying the geometry of the swirl chamber, particularly its height and radius, as well as the dimensions and shape of the projection 32.

[0036] Fig. 3 shows a view of the section plane BB in Fig. 1 The section plane now runs centrally through the liquid inlet 20. The liquid inlet 20 is cylindrical in its first section, then tapers and transitions into another cylindrical inlet channel, which ends at the opening 26 where the liquid to be sprayed enters the swirl chamber 24 tangentially. The outlet from the swirl chamber is shown in the view of the Fig. 3 not recognizable.

[0037] The first section 14 of the housing and the second section 16 of the housing are screwed together. The two sections 14 and 16 of the housing 12 can thus be easily separated from each other. According to the invention, the sections 14 and 16 can also be connected in other ways, for example by snap-fit ​​connections, clip connections, or a bayonet fitting.

[0038] During operation of the flat jet nozzle 10, the liquid to be sprayed is supplied via the liquid inlet 20. The liquid is then introduced tangentially at the opening 26 into the swirl chamber 24 and set into rotation within the swirl chamber 24. The liquid to be sprayed then reaches the outlet of the swirl chamber, is deflected by 90° and exits the housing 12 at the outlet opening 30. The cylindrical solid jet exiting the outlet opening 30 is deflected by the tongue 18 and directed to the Fig. 2 The flat beam, indicated by dashed lines, is fanned out.

[0039] The swirl chamber 24 creates flow resistance for the liquid being sprayed. This allows the volume flow through the flat jet nozzle 10 to be reduced by 50% to 70% compared to conventional flat jet nozzles or tongue nozzles without a swirl chamber. As a result, the free cross-sections within the housing 12 of the flat jet nozzle 10 can be significantly increased compared to conventional flat jet nozzles or tongue nozzles with the same volume flow. The flat jet nozzle 10 according to the invention is therefore extremely resistant to clogging.

[0040] Downstream of the swirl chamber 24, the deflection of the flow path by 90° (with a deflection angle between 70° and 110°) reduces the swirl of the liquid at the outlet of the swirl chamber. The solid jet exiting the outlet opening 30 therefore exhibits no rotation or only very slight rotation. This allows the tongue 18 to generate a wide, fanned-out, flat jet with uniform liquid distribution and droplet size distribution.

[0041] Swirl chambers are known from hollow cone nozzles and solid cone nozzles, where they are used to impart rotation to the liquid being sprayed, thus generating a hollow cone or solid cone jet downstream of the outlet opening. In the flat jet nozzle 10 according to the invention, the swirl chamber 24 functions as a vortex restrictor and thus generates flow resistance. In principle, the use of a swirl chamber in a flat jet nozzle is counterproductive. However, the advantages of increasing the flow resistance and the resulting increase in the free flow cross-sections within the nozzle are surprising benefits that arise from the inclusion of the swirl chamber 24.

[0042] Fig. 4 Figure 1 shows a flat jet nozzle 100 according to a further embodiment of the invention. The flat jet nozzle 100 differs from the flat jet nozzle 10 of the Fig. 1 bis 3 only by a second housing section 116 of the housing 12. The first section 14 of the housing is identical to that of the flat jet nozzle 10 of the Fig. 1 bis 3 It has been explained and will therefore not be explained again.

[0043] The second section 116 of the housing 12 is screwed into the internal thread of the first section 14 of the housing 12. The second section 116 has the conical section 26 of the swirl chamber 24, the conical section 26 having the same dimensions as the flat jet nozzle 10 of the Fig. 1 bis 3 An outlet from the swirl chamber 24 leads into an elongated, straight outlet channel 120, which ends at an outlet opening 130. A cylindrical solid jet emerges from the outlet opening 130 and strikes a tongue 118, which then generates a flat jet that flows into the Fig. 4 It is indicated by a dashed line. It is in Fig. 4 to recognize that the flat jet from the flat jet nozzle 100 has a central axis that runs parallel to a feed direction in the liquid inlet 20.

[0044] The rotation of the flow at the outlet of the swirl chamber 24 is largely reduced along the course of the elongated outlet channel 120. The length of the elongated outlet channel 120 is dimensioned such that a flat jet sufficient for the requirements is generated.

[0045] Based on a comparison of Fig. 2 and 4 It can be seen that different geometries and flow directions of the emitted flat jet can be achieved by simply exchanging the second section 16, 116 of the housing 12. This modular design allows the flat jet nozzle 10, 100 according to the invention to be used very flexibly.

[0046] The Fig. 5 bis 10 Figure 1 shows a flat jet nozzle 1000 according to a third embodiment of the invention. The flat jet nozzle 1000 differs from the flat jet nozzle 10 of the Fig. 1 bis 3 exclusively through a drip-stop valve 1002. Furthermore, the flat jet nozzle 1000 is identical to the flat jet nozzle 10 of the Fig. 1 bis 3 It has been explained and will therefore not be explained again.

[0047] The drip-stop valve 1002 is designed for use at a liquid inlet. See the drip-stop valve 1002. Fig. 10The device features a sleeve 1004 in which a ball 1006 is preloaded against a valve seat on the sleeve 1004 by means of a coil spring 1008. Depending on the fluid pressure of the liquid to be sprayed and the preload force of the coil spring 1008, the ball 1006 opens or closes the fluid inlet. If the fluid supply is shut off, the pressure at the fluid inlet drops and the ball 1006 closes the valve seat on the sleeve 1004. This prevents dripping from the flat jet nozzle 1000.

Claims

1. Flat-jet nozzle (10) having a housing (12) with a liquid inlet (20) for liquid to be sprayed and an outlet opening (30), wherein provided in a flow path for the liquid to be sprayed within the housing (12) is a swirl chamber (24) between the liquid inlet (20) and the outlet opening (30), and the swirl chamber (24) is formed concentrically about a central longitudinal axis, and a swirl chamber inlet opens into the swirl chamber (24) tangentially to an imaginary circle about the central longitudinal axis, characterized in that at least one deflection of the flow path is provided downstream of the swirl chamber (24) in the flow path for the liquid to be sprayed.

2. Flat-jet nozzle according to Claim 1, characterized in that the deflection of the flow path is provided to be between 70 degrees and 110 degrees, in particular 90 degrees.

3. Flat-jet nozzle according to Claim 1, characterized in that the flat-jet nozzle (10) is designed as a tongue nozzle and provided downstream of the outlet opening (30) is a tongue (18) on which liquid emerging from the outlet opening (30) impinges, wherein the tongue (18) forms a deflection of the flow path.

4. Flat-jet nozzle (100) having a housing (12) with a liquid inlet (20) for liquid to be sprayed and an outlet opening (130), wherein provided in a flow path for the liquid to be sprayed within the housing (12) is a swirl chamber (24) between the liquid inlet (20) and the outlet opening (130), and the swirl chamber (24) is formed concentrically about a central longitudinal axis, and a swirl chamber inlet opens into the swirl chamber (24) tangentially to an imaginary circle about the central longitudinal axis, wherein disposed downstream of the swirl chamber is a rectilinear channel, the geometry of the latter, in particular the length and the diameter, being sized such that the rotation of the flow is reduced, characterized in that the flat-jet nozzle (100) is designed as a tongue nozzle and provided downstream of the outlet opening (130) is a tongue (118) on which liquid emerging from the outlet opening (130) impinges, wherein the tongue (118) forms a deflection of the flow path.

5. Flat-jet nozzle according to at least one of the preceding claims, characterized in that the swirl chamber (24) is formed concentrically about a central longitudinal axis.

6. Flat-jet nozzle according to at least one of the preceding claims, characterized in that a swirl chamber outlet is disposed concentrically with the central longitudinal axis.

7. Flat-jet nozzle according to at least one of the preceding claims, characterized in that a protrusion (32) protruding into the swirl chamber (24) is provided in the swirl chamber (24) on an end face of the swirl chamber (24) opposite the swirl chamber outlet.

8. Flat-jet nozzle according to Claim 7, characterized in that the protrusion (32) is conical and tapers in the direction of the swirl chamber outlet.

9. Flat-jet nozzle according to at least one of the preceding claims, characterized in that the swirl chamber (24) has a cylindrical portion (28) and a conically tapering portion (26), wherein the swirl chamber inlet opens into the cylindrical portion (28) and the swirl chamber outlet is disposed at the end of the conical portion (26) with a smaller diameter.

10. Flat-jet nozzle according to at least one of the preceding claims, characterized in that the housing (12) is formed in at least two parts, wherein a first portion (14) of the housing (12) comprises the liquid inlet (20) and a first portion of the swirl chamber (24) and a second portion (16; 116) of the housing (12) has a second portion of the swirl chamber (24) and the outlet opening (30; 130).

11. Flat-jet nozzle according to at least one of the preceding claims, characterized in that provided directly upstream or directly downstream of the liquid inlet is a drip stop valve (1002) which closes a flow path when the pressure of the liquid to be sprayed falls below a predefined pressure and opens the flow path when the predefined pressure is exceeded.

12. Flat-jet nozzle according to at least one of the preceding claims, characterized in that a central axis of an emitted spray jet is disposed parallel or perpendicular to a flow direction in the liquid inlet (20).