EP3246095B1 - Nozzle for spraying fluid - Google Patents

Description

The invention relates to a nozzle for spraying liquids with a nozzle housing and several outlet openings in the nozzle housing, each outlet opening being arranged at the end of an outlet channel through the wall of the nozzle housing and wherein the plurality of outlet openings are arranged in a circle on the nozzle housing.

From the French patent application FR 2 212 497 A1 shows a nozzle for spraying liquids. The nozzle has a nozzle housing and a plurality of outlet openings in the nozzle housing, each outlet opening being arranged at the end of an outlet channel through the wall of the nozzle housing. The outlet openings are arranged in a circle on the nozzle housing.

The German Offenlegungsschrift DE 32 11 886 A1 shows a device for introducing flushing liquids, in particular into a galvanizing drum. The rinsing liquids are passed through the device via fluid channels running separately from one another and exit the device on different circular lines.

The German patent specification DE 12 26 917 B shows a flame spray nozzle for flame spraying powders. In the area of the entry into the nozzle, the channels lie on two different concentric circles and in the area of the outlet openings on a common circular line.

From the publication WO 2011/146274 A1 shows a fuel atomizer nozzle. The outlet openings are located on an inside and on an outside on a common circular line.

The European published application EP 1 325 782 A2 shows a two-fluid nozzle for atomizing a liquid with a gas. The outlet openings are located on an inside and on an outside on a common circular line.

The German Offenlegungsschrift DE 42 38 736 A1 shows an atomizer for an oil burner.

The invention is intended to improve a nozzle for spraying liquids with regard to a distribution of the droplet spray produced.

According to the invention, a nozzle with the features of claim 1 is provided for this purpose. A nozzle according to the invention for spraying liquids has a nozzle housing and several outlet openings in the nozzle housing, each outlet opening being arranged at the end of an outlet channel through the wall of the nozzle housing. The plurality of outlet openings are arranged in a circle on the nozzle housing. An exit angle which the respective central axis of the outlet channel assigned to the outlet opening encloses with a central longitudinal axis of the nozzle housing is different at least between a first and at least one second outlet opening. The outlet openings therefore do not all emit a drop spray with the same outlet angle, but rather the outlet angle differs between different outlet openings. As a result, a larger area can be exposed to a drop spray than would be the case with a constant exit angle of all exit openings. With the nozzle according to the invention it is possible to provide a larger number of outlet openings on the nozzle housing than would be the case with a constant outlet angle for all outlet openings. Because every outlet opening emits a conical droplet spray. By cleverly choosing the individual exit angles, the individual conical droplet sprays can be arranged next to one another in such a way that they cover the largest possible area in a process room, but do not overlap or only slightly overlap. Particularly in the case of applications in the gas cooling area, a greater coverage of the injection plane with water can be ensured and shorter evaporation distances can be achieved with otherwise the same drop size and drop distribution. Specifically, with the invention, geometries for outlet openings and outlet channels can be used which produce a comparatively small opening angle of the conical emerging droplet spray. Compared to the prior art, the invention can then be used to arrange a larger number of such outlet openings with changing outlet angles, so that a greater coverage with all droplet sprays generated than with a conventional nozzle with constant outlet angles for all Outlet openings is achieved. Outlet openings that produce a small opening angle of the droplet spray produced can produce droplet spray with a distribution of the droplet sizes that fluctuates less than with outlet openings that produce a larger opening angle of the droplet spray produced. In this way, advantages can be achieved especially for applications in the gas cooling sector. Advantageously, two different exit angles to the central longitudinal axis of the nozzle housing are selected for the plurality of exit openings, but more than two different exit angles of the exit openings can also be used within the scope of the invention.

In a further development of the invention, several first outlet openings are arranged in a circle along an imaginary first circular line with a first radius and several second outlet openings are arranged in a circle along an imaginary second circular line with a second radius that is different from the first radius, the first and second circular lines to one another are concentric.

In this way, an annular impact surface can be achieved on a flat surface which is arranged perpendicular to the central longitudinal axis of the nozzle housing. As stated, the individual conical droplet sprays that emerge from the outlet openings are arranged in such a way that they do not overlap or only slightly overlap one another. In the context of the invention, however, the outlet openings can easily be arranged on more than two concentric circular lines, each with different outlet angles.

According to the invention, the mouth openings of the outlet channels on the inside of the wall of the nozzle housing lie on a common imaginary circular line.

In this way, essentially the same conditions can be achieved in the interior of the nozzle housing in the mouth area into the outlet channels for all outlet channels, so that it can be ensured that the droplet size and distribution of all droplet sprays dispensed through the outlet openings are essentially the same.

As an alternative to the arrangement described above, the mouth openings of the outlet channels on the inside of the wall of the nozzle housing can lie on two imaginary circular lines that are concentric to one another and the outlet openings can lie on a common imaginary circular line.

According to the invention, the nozzle is designed as a two-substance nozzle with an internal mixing chamber, the mixing chamber having a liquid inlet and a gas inlet. Two-substance nozzles are particularly advantageous for applications in the gas cooling sector. With the invention, conventional two-fluid nozzles can be improved with regard to the distribution of the droplet spray produced.

According to the invention, the mixing chamber is designed to be annular, the outlet channels extending from the mixing chamber.

In a further development of the invention, a conical distribution wall is provided, the annular mixing chamber being connected to the side of the distribution wall or on a peripheral edge of the distribution wall.

A conical distribution wall is used to divide an introduced liquid jet into a uniform thin film, which is then broken up into individual drops at the entrance of the mixing chamber by the gas jets also entering the mixing chamber.

In a further development of the invention, an imaginary extension of at least one gas inlet channel extends into the area of the circumference of the conical distribution wall.

In this way, the gas jets from the gas inlet channel or from several gas inlet channels strike the water film generated by means of the distribution wall exactly where it leaves the distribution wall. This promotes the tearing of the water film into individual drops.

Fig. 1

ein Düsengehäuse einer Zweistoffdüse nach dem Stand der Technik,

Fig. 2

eine Vorderansicht des Düsengehäuses der Fig. 1,

Fig. 3

eine Ansicht eines Düsengehäuses einer erfindungsgemäßen Zweistoffdüse von schräg oben,

Fig. 4

eine Ansicht des Düsengehäuses der Fig. 3 von vorne,

Fig. 5

eine schematische Darstellung der Verteilung der einzelnen kegelförmigen Tropfensprays, die aus den Austrittsöffnungen des Düsengehäuses der Fig. 3 austreten,

Fig. 6

eine Schnittansicht einer erfindungsgemäßen Zweistoffdüse mit dem Düsengehäuse der Fig. 3, wobei die Schnittebene entlang der Linie A-A in Fig. 4 verläuft,

Fig. 7

eine Ansicht auf die Schnittebene A-A in Fig. 4,

Fig. 8

eine teilweise Ansicht der Schnittebene B-B in Fig. 4 und

Fig. 9

eine teilweise Ansicht der Schnittebene A-A in Fig. 4.

Further features and advantages of the invention emerge from the claims and the following description of a preferred embodiment of the invention in conjunction with the drawings. In the drawings show:

Fig. 1

a nozzle housing of a two-fluid nozzle according to the state of the art,

Fig. 2

a front view of the nozzle housing of FIG Fig. 1 ,

Fig. 3

a view of a nozzle housing of a two-fluid nozzle according to the invention obliquely from above,

Fig. 4

a view of the nozzle housing of Fig. 3 from the front,

Fig. 5

a schematic representation of the distribution of the individual conical droplet sprays emerging from the outlet openings of the nozzle housing of Fig. 3 exit,

Fig. 6

a sectional view of a two-fluid nozzle according to the invention with the nozzle housing of FIG Fig. 3 , the cutting plane along the line AA in Fig. 4 runs,

Fig. 7

a view of the section plane AA in Fig. 4 ,

Fig. 8

a partial view of the section plane BB in Fig. 4 and

Fig. 9

a partial view of the section plane AA in Fig. 4 .

The representation of the Fig. 1 shows a nozzle housing 10 of a two-fluid nozzle according to the prior art. The nozzle housing 10 has several outlet openings 12 which are arranged along an imaginary circular line around a central longitudinal axis 14 of the nozzle housing. With the central longitudinal axis 14, outlet channels which are arranged in the wall of the nozzle housing 10 and which lead to the outlet openings 12 form a constant outlet angle that is the same for all outlet channels that are assigned to the outlet openings 12.

The representation of the Fig. 2 shows the nozzle housing 10 from the front. The outlet openings 12 arranged on an imaginary circular line around the central longitudinal axis 14 can be seen. A total of twelve outlet openings 12 are provided. Outlet channels 16 which end at the respective outlet openings 12 are shown in FIG Fig. 2 recognizable in sections. The representation of the Fig. 2 It can also be seen that the outlet channels 16 are all arranged at the same outlet angle, a respective central axis of the outlet channels 16 and the central longitudinal axis 14 of the nozzle housing enclosing the outlet angle.

The representation of the Fig. 3 shows a nozzle housing 20 of a two-fluid nozzle according to the invention. The nozzle housing 20 is provided with a plurality of first outlet openings 22 and with a plurality of second outlet openings 24. The first outlet openings 22 differ from the second outlet openings 24 in their arrangement on a front side of the nozzle housing 20 and, as will be explained below, in an outlet angle which the respective central axis of the the outlet openings 22, 24 associated with the outlet channel with the central longitudinal axis 14 of the nozzle housing 20.

The representation of the Fig. 4 4 shows a front view of the nozzle housing 20. It can be seen that all of the first outlet openings 22 are arranged such that their center points lie on a first imaginary circular line 26. The second outlet openings 24, on the other hand, are arranged such that their center points lie on a second imaginary circular line 28 on the front side of the nozzle housing 20. A radius, measured from the central longitudinal axis 14 of the nozzle housing 20, is greater for the first circular line 26 than for the second circular line 28.

In the front view of the Fig. 4 it can already be seen that an exit angle which the center axes of the exit channels associated with the first exit openings 22 enclose with the center longitudinal axis 14 of the nozzle housing 20 differs from the corresponding exit angle of the second exit openings 24. In particular, the exit angles of the first exit openings 22 are greater than the exit angles of the second exit openings 24. This is in FIG Fig. 4 it can be seen from the fact that at the outlet openings 24 a section of the mouth openings 30 of the respective outlet channels 34 can be recognized. In the case of the outlet openings 22, the corresponding mouth openings of the associated outlet channels 32 cannot be seen.

The representation of the Fig. 5 shows schematically drop sprays 42 and 44 emerging from outlet openings 22 and 24, respectively. It can be seen that the droplet sprays 42, 44 are each conical and that the droplet sprays 42, 44 are arranged in such a way that they do not touch one another. In this way, influencing the individual drop sprays 42, 44 can be avoided. At the same time, the droplet sprays 42, 44 are arranged such that their surface lines run approximately parallel in the area in which the smallest distance between two droplet sprays 42, 44 is present. As a result, the largest possible annular area can be continuously acted upon with the droplet sprays 42, 44 on an impingement surface and at the same time the individual droplet sprays 42, 44 are largely prevented from influencing one another. Based on Fig. 4 and 5 it can be seen that a total of eight first outlet openings 22 are provided, which then produce eight conical droplet sprays 42. In the same way, eight second outlet openings 24 are provided which produce eight conical droplet sprays 44.

Compared to the conventional two-fluid nozzle 10 of the Figs. 1 and 2 This means that more outlet openings are used, the first and second outlet openings 22, 24 and the associated outlet channels 32, 34 being dimensioned so that the conventional two-substance nozzle with the nozzle housing 10 of the Figs. 1 and 2 and the two-fluid nozzle according to the invention with the nozzle housing 20 of the Figures 3 and 4 dispense the same amount of liquid with the same ratio of air or gas to liquid. The cone angles of the individual droplet sprays 42, 44 can thereby be reduced compared to the cone angles of the droplet sprays emerging from the outlet openings 12 of the conventional two-substance nozzle. As a result, a more uniform distribution of the droplet diameters present in the individual droplet sprays 42, 44 can be achieved. For applications in the gas cooling area, the two-substance nozzle according to the invention with the nozzle housing 20 offers considerable advantages because it can ensure greater coverage of the injection plane with liquid, in particular water, and can also realize shorter evaporation distances.

The representation of the Fig. 6 shows a two-substance nozzle 50 according to the invention, which is provided with the nozzle housing 20, which is shown in FIG FIGS. 3 and 4 has already been shown. Fig. 6 shows a sectional view, the section plane AA in Fig. 4 has already been shown and wherein this sectional plane runs through two first outlet openings 22.

The two-substance nozzle 50 has an air inlet 52 and a water inlet 54, the air inlet 52 and the water inlet 54 being arranged concentrically to one another, and the water inlet 54 being arranged within the annular air inlet 52. Air entering the nozzle housing 20 is indicated by means of dashed arrows 56 and water entering the nozzle housing 20 is indicated by means of a dashed arrow 58.

Water enters through the water inlet 54, which initially narrows to a frustoconical shape. After a section 60 with a constant diameter, the water inlet channel widens conically again. The incoming water jet then hits a conical distribution wall 62, the cone tip of which lies on the central longitudinal axis of the nozzle housing 20. As shown by means of two small curved arrows in extension of arrow 58, the incoming liquid jet splits and is split by means of the distribution wall 62 into a film which moves on the conical distribution wall 62 in an approximately radial direction outward. The conical distributing wall 62 ends at a circumferential edge 64. At the circumferential edge 64, the distributing wall merges into an annular mixing chamber 66.

Starting from the air inlet 52, channels 68 lead in a straight line to the mixing chamber 66. According to the arrow 56, the entering air jets strike the liquid film in the area of the peripheral edge 64, which film is just leaving the distribution wall 62 at the peripheral edge 64. The liquid film is broken up into individual drops by means of the air jets. The The drop-air mixture then moves through the annular mixing chamber 66 and is further intimately mixed, so that a drop spray can then emerge at the outlet openings 22, 24. How with the Fig. 5 has already been explained, a conical droplet spray 42 emerges from the outlet openings 22. The second outlet openings 24 are shown in the sectional view of FIG Fig. 6 not recognizable.

The representation of the Fig. 7 FIG. 8 shows an enlarged sectional view of the nozzle housing 20, the sectional plane running through flat tool engagement surfaces 70 on the outside of the nozzle housing 20, see FIG Fig. 3 . In Fig. 7 the double exit angle W1 is shown, which lies between the central axes 72 of the exit channels 32 of two exit openings 22 lying in the sectional plane. In the context of the present description, however, an angle which the central axes 72 of the outlet channels 32 enclose with the central longitudinal axis 14 of the nozzle housing 20 is referred to as the exit angle. This exit angle is therefore W1 / 2. In the embodiment shown, the exit angle of the first exit openings, ie the angle W1 / 2 which the central axes 72 of the exit channels 32 enclose with the central longitudinal axis 14 of the nozzle housing 20, is approximately 55 °. The angle W1 is in Fig. 7 thus about 110 °.

Fig. 8 shows a partial sectional view on the plane BB in FIG Fig. 4 . The cutting plane BB runs through two second outlet openings 24, with FIG Fig. 8 the sectional view is shown only up to the central longitudinal axis 14 of the nozzle housing 20. An outlet channel 34 is assigned to each of the outlet openings 24. An angle which the central axis 74 of the outlet channels 34 encloses with the central longitudinal axis 14 of the nozzle housing 20 is shown in FIG Fig. 8 designated with W2 / 2. In the embodiment shown, this exit angle is approximately 40 °.

Fig. 9 FIG. 11 shows a partial view of the section plane AA in FIG Fig. 4 , wherein the cutting plane runs through two first outlet openings 22. The sectional plane is only shown up to the central longitudinal axis 14 of the nozzle housing 20. As already with the Fig. 7 has been explained, the central axes 72 of the outlet channels 32, which are assigned to the first outlet openings 22, with the central longitudinal axis 14 of the housing 20 assume an exit angle W1 / 2, which in the embodiment shown is approximately 55 °. The exit angle W1 / 2, which is assigned to the first exit openings 22, is thus greater than the exit angle W2 / 2, which is assigned to the second exit openings 24. The effects of these different exit angles are shown in the schematic illustration of Fig. 5 to recognize.

In the Fig. 7 , 8 and 9 it can also be seen that the mouth openings of all outlet channels 32, 34 on a common imaginary circular line on the inside of the wall of the Nozzle housing 20 are. As a result, the outlet channels 32, 34 prevail in the area of the mouth openings due to the rotationally symmetrical structure of the two-substance nozzle 50, see Fig. 6 , identical ratios, so that the drop size and drop distribution within the drop sprays 42, 44, see Fig. 5 , is essentially the same.

Claims (5)

1. Nozzle for spraying liquids, having a nozzle housing (20) and a plurality of outlet openings (22, 24) in the nozzle housing (20), wherein each outlet opening (22, 24) is arranged at the end of an outlet passage (32, 34) through the wall of the nozzle housing (20), and wherein the plurality of outlet openings (22, 24) is arranged in a circle on the nozzle housing (20), wherein the nozzle is designed as a dual-substance nozzle (50) having an internal mixing chamber (66), wherein the mixing chamber (66) has a liquid inlet and a gas inlet, wherein an outlet angle (W1/2, W2/2) which the respective central axis (72, 74) of the outlet passage (32, 34) associated with the outlet opening (22, 24) encloses with a central longitudinal axis (14) of the nozzle housing (20) differs between at least one first and at least one second outlet opening (22, 24), characterized in that the mixing chamber (66) is of annular design, wherein the outlet passages (32, 34) start from the mixing chamber (66), and in that mouth openings (30) of the outlet passages (32, 34) are located on the inner side of the wall of the nozzle housing (20) on a common imaginary circular line.
2. Nozzle according to Claim 1, characterized in that a plurality of first outlet openings (22) is arranged in a circle along an imaginary first circular line (26) having a first radius, and a plurality of second outlet openings (24) is arranged in a circle along an imaginary second circular line (28) having a second radius, which is different from the first radius, wherein the first and the second circular lines (26, 28) are concentric with respect to one another.
3. Nozzle according to Claim 1, characterized in that mouth openings of the outlet passages (32, 34) on the inner side of the wall of the nozzle housing are located on two mutually concentric imaginary circular lines and in that the outlet openings (22, 24) are situated on a common imaginary circular line.
4. Nozzle according to one of the preceding claims, characterized in that a conical distribution wall (62) is provided, wherein the annular mixing chamber (66) adjoins a circumferential edge (64) of the distribution wall (62).
5. Nozzle according to Claim 4, characterized in that an imaginary extension of at least one gas inlet passage extends into the region of the circumferential edge (64) of the conical distribution wall.

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