MXPA00004524A - Slit nozzle for spraying a continuous casting product with a cooling liquid - Google Patents

Abstract

The inventive spray nozzle (5) comprises a mixing chamber (15) into which a liquid (7) forming a first and a second liquid flow (12, 13) flows through two inlet openings (9, 10) and which has an outlet opening (30) for a spray jet (40), said outlet opening (30) being located downstream. A mixing chamber wall (16, 17) acts as a guiding surface for the flows of liquid (12, 13) and in the area of the outlet opening (30) is shaped in such a way that the flows of liquid (12, 13) meet at said outlet opening at an angle (&agr;), hereby forming the spray jet (40). This spraying process delivers drops with high levels of kinetic energy and produces a broad, even fanning of the drop paths with an angle of impact (&agr;) of almost 90°. As a result, the inventive spray nozzle can be used to spray large surfaces particularly evenly from a great distance.

Description

GROOVED NOZZLE FOR SPRAYING A CONTINUOUS COLD PRODUCT WITH A COOLING LIQUID DKSCTRIPTION OF THE INVENTION The present invention relates to a spray nozzle for spraying a continuous casting product with a cooling liquid according to the preamble of claim 1. As is known, in the continuous casting, particularly in the continuous casting of steel, a continuous casting product is obtained by cooling a molten metal in a continuous cast ingot mold, said product being continuously extracted from the ingot mold in the form of a Casting bar whose surface is constituted by a solidified crust and which still comprises a liquid core of molten metal. After the exit of the ingot mold, the strand is conducted through a secondary cooling zone, in which it is sprayed with cooling medium, in general water to continue extracting heat until its total solidification and to bring it to the desired temperature for the further processing. As the secondary cooling causes or has a direct influence on the solidification of the cast bar, the secondary cooling process and the devices required for its realization are decisive for the quality of the final products. Of particular importance are the components used for the distribution of the medium of Ref: 119551 cooling, particularly the spray nozzles. The various parameters that characterize the secondary cooling process have different effects on the solidification of the bar and must be optimized -according to the application according to different criteria. Of particular importance are the intensity of the secondary cooling that determines the rate of growth of the crust of the bar and that according to the application is more or less hard or soft and the spatial distribution of the incidence density of the cooling medium that should be as homogeneous as possible to ensure the most homogenous growth of the crust of the bar. The spray nozzles used in a secondary cooling section for spraying a cooling medium are generally optimized with respect to the requirements regarding the intensity of the secondary cooling and the homogeneity of the incidence of the cooling medium. Determinant for the intensity of secondary cooling is specifically the kinetic energy of the sprayed liquid droplets and particularly the incidence density of the cooling medium. Decisive for the homogeneity of the incidence density of the cooling medium is not only the homogeneous distribution of the droplets in the spray jet generated with a single spray nozzle. The angular distribution of the droplet trajectories is also relevant for the homogenity of the incidence density of the cooling medium. Indeed, the angular distribution determines the shape and magnitude of the surface capable of being sprayed with a spray jet on a bar. In a secondary cooling zone, however, a plurality of spray nozzles are required to cover by cooling the entire surface to be cooled by a bar. Accordingly, the spray jets of the different nozzles are correspondingly superimposed. The angular distribution of the droplet trajectories of an individual spray jet is therefore decisive for the homogeneity of the incidence density of the cooling medium in the case of superposition of a plurality of spray jets. The known solid cone nozzles provide spray jet with an angular distribution of cone shape of the droplet paths. Due to its conical shape, the spray jets of several solid cone nozzles can not perfectly cover large spray surfaces; the superposition of several spray jets translates into an incidence density of the cooling medium with a lack of homogeneity. On US-3 072 346, a spray nozzle with all the features of the preamble of claim i is known. This spray nozzle comprises a nozzle body with a mixing chamber that is substantially symmetrical with respect to the longitudinal axis of the nozzle body, which is provided with two inlet openings through which a liquid can penetrate, constituting respective liquid flows first and second and of an outlet opening, arranged downstream, for a spray jet. Regardless of the configuration of the outlet opening, this nozzle has essential characteristics of a known type of a solid cone nozzle: the two inlet openings are integrated in such a way - in a guiding structure for the liquid flows that penetrate into it. the mixing chamber that said liquid flows receive, upon entering the mixing chamber, in addition to a velocity component in the direction of the outlet opening, a velocity component tangential to the wall of the mixing chamber. Due to this tangential velocity component, the two liquid streams collect, after their entry into the mixing chamber, into a liquid flow directed towards the outlet opening that has a torsion about the longitudinal axis of the nozzle body. Although the spray nozzle described in US-3 072 346 has - like a conventional solid cone nozzle - a circular outlet opening, said outlet opening is enlarged on its outlet side in a funnel-shaped manner so that the jet of outgoing spray is deformed in the direction of the diagonals of a square. Due to this configuration of the outlet opening the nozzle provides a spray jet with droplet distribution practically square - with respect to a plane perpendicular to the longitudinal axis of the nozzle body. A drawback of this spray nozzle is that the shape of the droplet spray pattern distribution is deformed more and more as the liquid inlet pressure increases, because of the torsion imparted. Accordingly, with such a nozzle the requirements imposed on the homogeneity of the incident density of the cooling medium in a secondary cooling section can not be met. A further drawback of this nozzle is that its spray jet has a nearly square distribution of the droplets only in a spray plane which can not be far from the outlet opening, typically not more than 20 cm. Due to the reduced operating distance, a large number of spray nozzles of this type are required to spray large surfaces with sufficient homogeneity.

In US 4 988 043 a flat jet nozzle is described. This presents a passage channel for the liquid to be sprayed with an outlet slot for the spray jet. The spray jet is fanned in the direction of the groove, over a wide angular area, while transversely to the longitudinal direction of the groove hardly widens as the distance from the outlet slot increases. The almost one-dimensional fan distribution gives rise to a flat spray jet. Due to the small extension of the jet transversely to the outlet slot, the spraying of large rectangular surfaces brings complications, either because a large number of these flat jet nozzles must be used or because a single nozzle must be moved to sweep with its jet. sprinkling a large surface. Starting from the deficiencies of the known spray nozzles, the purpose of the present invention is to provide a spray nozzle which is suitable for use in a secondary cooling section of a continuous casting plant and which for this purpose allows spraying, from a distance as large as possible, a surface as large as possible in the most homogeneous way possible, with drops of liquid with kinetic energy as large as possible. The aforementioned purpose is achieved by means of a spray nozzle with the features of claim 1. The spray nozzle according to the invention comprises a mixing chamber in which, through two inlet openings, a liquid can penetrate forming separate flows of liquid. first and second liquid, and having an outlet opening, arranged downstream to a spray jet, with at least one wall of the mixing chamber being made as a guide surface for the liquid flows and shaped so that in the outlet opening the liquid flows converge to the outlet opening, or immediately before it, at an angle and thus form the spray jet. Because the two liquid flows are oriented towards the outlet opening and collide with each other in the outlet opening, relatively large drops of liquid - which, with respect to the inlet pressure - in the inlet openings, may occur the exit opening with a relatively large kinetic energy. Energy losses due to swirling in the mixing chamber are greatly avoided. The high kinetic energy allows a large operating distance when spraying a surface. The spraying of the two liquid streams allows a great dispersion of the directions of propagation of the drops and therefore a wide distribution in fan of the spray stream projecting from the outlet opening. An essential contribution for fan-spread of the spray jet is particularly provided by droplets which, when the liquid flows collide with one another, are dispersed transversely to the direction of propagation of the liquid flows. Since the propagation of the liquid streams in the mixing chamber is determined essentially by the geometry of the mixing chamber, the inlet pressure can be varied over a relatively large range without substantially changing the fan distribution of the jet stream. aspersion. In this respect, under cross-section of an inlet opening, a cross-section to the respective flow of the liquid in the inlet opening is basically understood, and a section cross-sectioned to the spray jet under the cross-section of the outlet opening. The properties of a spray jet produced with the spray nozzle according to the invention depend essentially on the angle of incidence under which the flow of the liquid converges in the outlet opening or immediately before it. It is advantageous to choose the angle of incidence within an angle comprised between 60 and 130 degrees, preferably between 80 and 100 degrees, in this way suitable conditions are created for the generation of droplets of liquid that leave the outlet opening with a particularly high kinetic energy and form a spray jet characterized in that the droplets are distributed in a particularly uniform manner around a direction propagation medium and at a particularly large spatial angle. In one embodiment of the spray nozzle according to the invention, the mixing chamber has, at the outlet opening, a narrowing with an opening angle at the exit opening comprised between 60 and 130 degrees, preferably between 80 and 100. degrees. The constriction constitutes that part of the guiding surface for the liquid flows that determines the angle of incidence. The constriction gathers both liquid flows in the outlet opening at an angle of incidence corresponding to the angle of opening in the stratum. The droplets formed during the interaction between both liquid flows in the outlet opening have a particularly large velocity component in the bisecting direction of the narrowing angle. This direction corresponds to the average direction of propagation of drops that can leave the exit opening. In addition, the outlet opening frees-according to its shape-the path for drops whose trajectories are scattered at a spatial angle around the average direction of propagation. The narrowing can, for example, have a conical shape.

Another embodiment of the spray nozzle according to the invention has a groove as the outlet opening. An outlet slot offers - in the case of a suitable configuration of its cross-sectional area to the direction of propagation of the spray jet - the possibility of spraying, for example, a rectangular surface. The long sides of the rectangular spray surface are located especially parallel to the direction of the longitudinal extension of the groove. The angular area on which the spray jet is fanned out in the direction of the longitudinal extension of the outlet slot is greater the longer the "slot." This effect is justified by the fact that the angular zone in which can drop, through the outlet slot, the interaction zone of the two liquid flows in the outlet opening, is greater in the direction of the longitudinal extension of the slot the longer the exit slot A series of other embodiments of the spray nozzle according to the invention have additional characteristics, which alone or in combination offer the conditions for a homogeneous distribution of droplets on a spray surface. advantageous that the outlet opening and the mixing chamber have a common plane of symmetry, under this condition the two liquid flows are symmetrical with n with respect to the plane of symmetry. In this way drops can be produced whose trajectories are symmetrical with respect to the plane of symmetry. In a spray nozzle whose outlet opening is designed as a groove, a particularly homogeneous distribution of droplets is obtained if the inlet openings have respectively oblong-shaped cross-sectional areas and the directions of their longitudinal extension are arranged essentially parallel to each other. the direction of the longitudinal extension of the exit slot. In this case, the two liquid streams are premolded in the inlet openings and adapt to the outlet slot in the sense that the lines of the same flow velocity -with respect to a plane transverse to the respective liquid flow- present already in the inlet openings the same or substantially the same shape as the cross-sectional area of the outlet opening. { transversely to the average direction of propagation of liquid drops). Another embodiment of the spray nozzle according to the invention has an outlet groove and is configured in such a way that the mixing chamber and the outlet groove have a common plane of symmetry, the longitudinal direction of the groove being located exit in the plane of symmetry and the entrance openings are arranged on different sides respectively of the plane of symmetry. In this case, the spray jet is fanned out in a particularly wide manner in the plane of symmetry, ie in the longitudinal direction of the outlet slot. Additionally, the droplet distribution is particularly homogeneous if - as in the example described above - the inlet openings have an oblong cross-sectional area and the directions of their longitudinal extension are essentially parallel to the plane of symmetry . A particularly uniform droplet distribution is achieved when the ratio between the sum of the two surfaces - cross section of the inlet openings and the outlet opening cross sectional area is between 1.5 and 2, and preferably between 1.6 and 1.8. . A further embodiment of the spray nozzle is characterized in that the mixing chamber has a narrowing of the type mentioned above, arranged in an outlet opening and a cylindrical portion between the narrowing and the inlet openings. The cylindrical portion acts as a lateral wall that delimits the liquid flows. The length of the cylindrical element has an influence on how the two liquid flows in the outlet opening are intermixed and how efficiently the liquid flows are transformed into droplets that leave the exit opening unimpeded. The length of the cylindrical portion can be correspondingly optimized. In addition, it is advantageous if the inlet openings open next to the side wall of the mixing chamber. Then the energy losses due to an undesired formation of eddies in the mixing chamber, they are particularly reduced and the generation of the spray jet becomes especially efficient. A spray nozzle with a mixing chamber of particularly simple construction is obtained if the inlet openings are formed between a transverse partition, which joins between opposite parts of the lateral delimitation of the liquid streams, and the lateral delimitation itself. With a rotationally symmetrical side wall with respect to an axis and a parallel-transverse cross partition, the inlet openings have cross-sections in the form of circle segments. According to the invention, such inlet openings can be combined as an outlet groove whose longitudinal direction is essentially parallel to the ropes of the circle segments. The distribution of droplets in the spray jet can be influenced by defined widens of the cross section of the outlet opening in the direction of propagation of the spray jet. An embodiment of the spray nozzle according to the invention has an outlet groove whose cross-sectional area is widened at the ends of the narrow or narrow sides in the direction of propagation of the spray jet. In this way a particularly large fan distribution of the spray jet in the longitudinal direction of the outlet slot is achieved. In a further embodiment of the spray nozzle, the cross section of the outlet slot is enlarged in the central part of the wide sides of the outlet slot in the direction of propagation of the spray jet. With this measure the number of drops that propagate in the direction of the average direction of propagation can be increased. In a further embodiment of the spray nozzle according to the invention, it is provided that the outlet opening and the mixing chamber have a common plane of symmetry and that for the delimitation of the spray jet projecting from the outlet opening they are provided. guide walls. In other embodiments of the spray nozzle according to the invention, the spray nozzles are asymmetric in that the inlet openings have different cross-sectional surfaces and / or the guide walls on opposite sides of the outlet opening are arranged with different separation to the exit opening. These two constructional measures induce, on the inlet side and / or on the outlet side, an asymmetry of the spray nozzle which -even with an otherwise symmetrical mixing chamber- influences the distribution of droplets in the spray jet. aspersion. By means of a quantitative marking of this symmetry, it is possible, in comparison with a symmetric nozzle, to displace the center of gravity of the droplet distribution at a preset distance, to influence the homogeneity of the distribution of. drops and vary the shape of the spray surface. Among other things it is possible to obtain - instead of a rectangular spray surface - spray surfaces with more or less curved perimeter lines. In a spray nozzle, the mixing chamber of which has a plane of symmetry, a particularly homogeneous droplet distribution is obtained on a rectangular spray surface with a center of gravity offset from the plane of symmetry, if the nozzle is asymmetrically configured, such on the input side and on the output side, that the entry opening with the smaller cross-sectional area is located on the same side of the plane of symmetry as that of the guide wall having the greatest distance from the plane of symmetry . For optimization, the distances of the guide walls from the plane of symmetry to the asymmetry at the inlet side of the nozzle can be adapted, which is characterized, for example, by the difference in size between the cross-sectional areas of the apertures of the nozzle. entry. With a spray nozzle according to the invention, equipped with an appropriate outlet slot, for example, it is possible to spray uniformly, from approximately 45cm away, a rectangular surface with 10cm wide and 50cm long. In a secondary cooling section of a continuous casting installation, spray nozzles of this type can be used, advantageously for the cooling of cast bars with billet or roughing format, and one of the spray nozzles can be replaced with 4-6 conventional nozzles. solid cone and also allowing a more uniform contribution of the cooling medium. The nozzle according to the invention can be realized with an exit groove with a length of more than 10mm and a width of more than 5mm. With openings of this magnitude, the risk that the outlet slot of the spray nozzle according to the invention becomes clogged by fouling during operation is reduced, quite the opposite of conventional spray nozzles. The same applies to the entrance openings, which can be chosen approximately equal in size to the exit openings. The asymmetric embodiments of the spray nozzle according to the invention find various applications in a continuous casting installation. For example, in a curved continuous casting plant, portions of a curved bar with a rectangular cross-section on the various faces can be cooled in the region of the secondary cooling section by superimposing spray surfaces in the form of rectangles and portions of circular hoops. Such spray surfaces can be generated with the spray nozzle according to the invention by appropriate sizing of its components. It is also common in the casting process, and in successive castings to vary the cross section of the bars that must be manufactured. This results in the problem that, after a cross-sectional variation in a longitudinal section of a bar path, it is not only necessary to adapt the magnitude of the spray surface to the modified geometry of the bar, but frequently also the center of gravity of the spray surface. Using conventional spray nozzles would have to be replaced by varying the cross section, all the spray nozzles by others with a different spray surface should also be adapted conventionally the position of the spray nozzles. The same objective can be achieved, by means of the spray nozzle according to the invention, by the fact that the nozzles are placed at a predetermined point and, possibly, spray nozzles with different asymmetry are used, considering the variation of the centers of gravity of the surfaces of aspersion. With this way of proceeding, the costly step of re-adjusting the spray nozzle with each variation of cross-section can be dispensed with. In the following, embodiments of the spray nozzle according to the invention will be described in more detail with reference to the accompanying drawings, in which: FIGURE IA is a longitudinal sectional view of a spray nozzle; FIGURE IB is a view in longitudinal section of the spray nozzle of FIG. IA, according to line B-B; FIGURE 2A is a cross-sectional view of the spray nozzle of FIG. 1A according to line A-A; FIGURE 2B is a plan view of the spray nozzle of FIG. 1A according to arrow C in FIG. IB; FIGURE 2C is a view analogous to FIG. 2B but from another example; FIGURE 3A is a view analogous to FIG. 2A, but with inlet openings of different sizes; FIGURE 3B is a view analogous to FIG. 2B, but with guide surfaces on the outlet side with different separations to the outlet opening; and FIGURE 3c, is a view analogous to FIG. A, but with the modifications according to FIGS. 3A and 3B. The two spray nozzles illustrated in Figs. 1A-B and 2A-C, are intended for spraying a rectangular surface with drops of liquid. The spray nozzle 5 illustrated in Figs. 1A-B and 2A-B, is symmetrical with respect to a plane 35. The spray nozzle 5 comprises a nozzle body 4, which has a hollow cavity constituted by a cylindrical portion 16 and a conical portion 17. The cylindrical part possesses a an opening 6 through which a liquid that can be sprayed can penetrate under a certain pressure p, and is rotationally symmetrical with respect to a longitudinal axis 38. The conical portion 17 tapers in the direction of the longitudinal axis 38 at an angle opening and has an outlet slot 30, for a spray jet 40 at the tip of the cone. The outlet slot 30 is symmetrical with respect to the plane of symmetry 35 with the longitudinal direction of the cross-sectional area of the slot 30 in the plane of symmetry 35. As can be seen from FIGS. 2A and 1A-B, a transverse partition 8 delimits in the cylindrical portion 16 a mixing chamber 15, constituted by a portion of the cylindrical portion 16 and the conical portion 17 and leaves free next to the wall of the cylindrical portion 16, two inlet openings 9 and 10. The cross-sectional surfaces of the inlet openings 9 and 10 have the shape of a circle segment and are arranged symmetrically on respective sides of the plane of symmetry 35. The cross-sectional areas of the openings input 9 and 10, have an oblong shape with the directions of their longitudinal extension or the ropes of the circle segments, parallel to the plane of symmetry 35. During operation, it is fed to the spray nozzle 5 under a pressure p, through the opening 6 and along flow lines 7 a liquid to be sprayed which is conducted through the inlet openings 9 and 10, forming a first stream of liquid 12 and a second stream of liquid 13 in the mixing chamber 15. In case of suitable selection of the opening angle or;, of the conical portion 17, of the diameter D, and of the length L, of the cylindrical portion 16 that it limits the mixing chamber 15 (Fig. IB), the two streams or liquid flows 12 and 13 are conducted along the walls of the cylindrical portion 16 and the conical portion 17, to converge in the outlet opening 30 and form the spray jet 40. In Fig. IB, is denoted by TL the angle designating the fan distribution of the spray jet in the plane of symmetry, that is to say, it characterizes the angular zone in which droplets leaving the opening 30 are scattered in the plane of symmetry 35. Analogously it is designated with? in FIG. IA the angular zone on which droplets are distributed perpendicularly to the plane of symmetry 35. As indicated in "Figs. IA and IB, in the spray nozzle 5 at an angle TL is considerably greater than?. In order to allow as many drops as possible to pass through the outlet slot 30 at the ends of the narrow sides of said outlet slot 30, a widening is provided at the ends of the narrow sides of the outlet slot 30. 31 of the cross-sectional area of the outlet slot 30 in the direction of propagation 39 of the spray jet 40. FIG. 2C shows an alternative configuration of the outlet slot 30. The cross section of the outlet slot 30 in FIG. 2C has, in the central part of the long sides, widening 32 in the direction of propagation 39 of the spray jet 40. Said enlargements give rise to an accumulation of droplets within the plane of symmetry 3 5, in the direction of the longitudinal axis 38. Guide walls 45, 46 are arranged essentially parallel to the plane of symmetry 35. Said guide walls act -according to the distance from the plane of symmetry 35- as a limitation of the spray jet 40 that exits. by the outlet opening 30 and / or for the protection of the spray jet 40 with respect to external disturbances, for example movements of the surrounding air. In the example of Figs. ÍA and IB an opening angle OI = 90 ° has been chosen. OI = 90 ° is a preferred value for the homogeneity of the droplet distribution in the spray jet 40, the amplitude of the fan distribution of the spray jet 40 and the efficiency of droplet generation. However, the spray nozzle also works for 60 <; a < 130 ° being 80 < I HEARD < 100 ° a preferred interval. By means of the spray nozzle according to the invention, according to Figs. ÍA and IB, it is for example possible to uniformly spray from a distance of 450mm from the exit opening, a rectangular surface of a size of I20mm x 500mm. The angular distribution of the trajectories of the drops is then characterized by TL = 58 ° and? = 16 °. For this spray field, according to the size of the outlet slot 30, homogenous droplet distributions are obtained for a given magnitude of the chamber.

Mixed 15, and a certain cross-sectional area of the inlet openings 9, 10. Thus for example, for an outlet slot 30 with the length 1 = 13.8mm and the width B = 7mm results a homogeneous distribution of droplets for a mixing chamber 15 with D = 26mm and L = iimm. Simultaneously the optimum ratio between the sum of the two cross-sectional surfaces of the inlet openings 9 and 10 and the cross-sectional area of the outlet opening 30 has a value of 1.7 ± 0. i. Due to the high efficiency of the droplet generation, the spray jet 40 produces a pressure p = 90 bar at the inlet 6 of the spray nozzle on a spray surface at a distance of 450 mm, a high pressure of shock of 30 kg / m2. The operating pressure p, is between 1 bar and 10 bar. In the case of a cross-sectional area smaller or larger than the outlet slot 30, it is necessary to reduce or increase, L and D correspondingly. Specifically, the optimum ratio between the sum of the cross-sectional areas of the inlet openings and the cross-sectional area of the outlet opening is between 1.5 and 2, preferably between 1.6 and 1.8, and the optimum ratio between the diameter D of the cylindrical portion 16 and the length L of the cylindrical portion 16 in the mixing chamber 15 is between 2 and 3. The impact pressure with the same reference distance is correspondingly smaller or greater respectively. Figs. 3A-C, illustrate an asymmetric spray nozzle 50 which can be considered as a variant of the above-described spray nozzle 5, characterized by the plane of symmetry 35. The asymmetric spray nozzle 50 differs from the symmetrical spray nozzle 5 by the The fact that the transverse partition 8 is displaced with respect to the plane of symmetry 35 the inlet openings 9 and 10 therefore constitute a circle segment with different surfaces Ax and A2, and the guide surfaces 45 and 46 have different separations ti and t2 , with respect to the center of the outlet opening 30. In the case of the asymmetric spray nozzle 50, AL < A2, and j. > t2 is to say that the entrance opening of the 9 and 10 having the smallest cross-sectional area is arranged on the same side of the plane of symmetry 35 as that of the guide walls 45 and 46 which has the greatest distance from the plane of symmetry 35. Due to the different configuration or sizing of the inlet openings 9 and 10, the liquid streams 12 and 13 convey different quantities of liquid (indicated in FIG. 3C by arrows with a line thickness corresponding to the amount of liquid). As in this configuration there is no symmetry between the liquid flows 12 and 13 with respect to the symmetry plane 35 and therefore, as the liquid flows converge, drops with an asymmetric pulse distribution are produced, the spray jet 40 being characterized, depending on the distance x from

Claims (17)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1.- Spray nozzle for spraying an ingot mold with a cooling liquid, with a mixing chamber, in which it flows to the inside a liquid by two inlet openings, forming a first and a second stream of liquid, and with an outlet slot, arranged downstream, for a spray jet, characterized in that, at least one mixing chamber wall is formed as guide surface for the liquid streams and is thus formed in the outlet slot, that the liquid streams are in the outlet slot at an angle. { a) which is between 60 ° and 130 ° preferably between 80 ° and 100 °, and thus form the outlet jet.
2. 2. - Spray nozzle according to claim 1, characterized in that, the mixing chamber has in the exit slot an angoetamiento with an opening angle (OI) in the outlet slot between 60 and 130 °, preferably between 80 ° and 100 ° or the narrowing forms a part of the guide surface.
3. 3. Spraying nozzle according to claim 2, characterized in that the mixing chamber has a cylindrical segment between the narrowing t and the inlet openings.
4. 4. - Spraying nozzle according to one of claims 1-3, characterized in that the inlet openings have respective transverse cutting surfaces with an elongated shape and the directions of their longitudinal stretching are in each case substantially parallel to the direction of the longitudinal stretch of the exit slot.
5. 5. - Spray nozzle according to one of claims 1-3, characterized in that the outlet slot and the mixing chamber have a common symmetry plane.
6. 6. - Nozzle according to one of claims 1-5, characterized in that, the mixing chamber has a side wall laterally limiting the liquid streams and the inlet openings each time they open next to the side wall in the mixing chamber .
7. 7. Nozzle according to claim 6, characterized in that the inlet openings are formed between the side wall and a transverse rod.
8. 8. - Spray nozzle according to one of the claims 1-7, characterized in that, the longitudinal direction of the outlet slot is in a plane of symmetry and the entry openings are arranged on different sides of the plane of symmetry.
9. 9. - Spray nozzle according to one of claims 1-8, characterized in that the cross section of the inlet openings is in the form of a circular section.
10. 10. - Nozzle according to one of claims 1-9 characterized in that the cross-sectional surface of the outlet slot has an extension on the narrow sides in the direction of the widening of the spray jet.
11. 11. - Spray nozzle according to one of claims 1-10, characterized in that the cross section of the outlet slot in the center of the long sides of the outlet slot in the direction of broadening of the outlet jet presents an extension.
12. 12. Spraying nozzle according to claim 1, characterized in that, in order to limit the spray stream leaving the outlet slot, guide walls are arranged in the direction of the longitudinal stretching of the outlet slot.
13. 13. - Spray nozzle according to one of claims 1-12, characterized in that the ratio of the sum of both cross-sectional surfaces of the inlet openings to the transverse surface of the outlet slot is selected between 1.5 and 2, preferably between 1.6 and 1.8.
14. 14. - Spray nozzle according to claim 3, characterized in that the ratio of the diameter of the cylindrical segment to the length of the cylindrical segment is selected between 2 and 3.
15. 15. Nozzle according to one of the claims 1-14., characterized in that the inlet openings have different cross-sectional surfaces.
16. 16. Nozzle according to one of claims 12 ee 15, characterized in that - the guide walls are arranged on opposite sides of the outlet slot at different distances from the outlet slot.
17. 17. - Nozzle according to one of claims 5, 15 and 16, characterized in that the entry opening with the smallest cross-sectional surface is arranged on the same side of the symmetry-plane as that of the guide walls. , which presents the greatest distance from the plane of symmetry. SSSOMSN OF THE INVENTION The spray nozzle (5) comprises a mixing chamber (15) in which, through two inlet openings (9, 10), a liquid (7) can penetrate, constituting both first and second liquid flows. second (12, 13) and having an outlet opening (39), arranged downstream, for a spray jet (40). A wall (16,17) of the mixing chamber acts as a guiding surface for the liquid flows (12, 13) and is shaped in such an inlet-outlet (39) that the liquid flows (12, 13) converge in the exit opening at an angle (a) of practically 90 °, drops of high kinetic energy and a wide and uniform fan distribution of the droplet trajectories. Accordingly, a particularly uniform spraying of large surfaces from a great distance by means of said spray nozzle is possible.