SPRAY HEAD, ESPECIALLY FOR MAKING SNOW

Description

[0001] The present invention relates to the field of snow production to enable the practice of winter sports, such as skiing, on a slope when, for example, its snow cover is low.

[0002] More specifically, the invention relates to a spray head for generating ice crystals or snowflakes. Such a spray head is generally mounted high on a pole at the edge of a ski slope. In this way, the artificially produced snow can be projected into the air and fall back down, spreading over an area of ​​the ski slope.

[0003] Generally, and as described in document FR 2784905, it is known to use a spray head comprising a jacket and at least one nozzle to spray pressurized water. Such a jacket allows water to be conveyed, via one or more internal channels, from a pressurized water supply to the nozzle(s).

[0004] However, the effectiveness of such spray heads can be reduced when the ambient air temperature is between -5°C and 0°C. This is because the higher the ambient temperature, the longer it takes for water sprayed by a spray head to solidify. Consequently, at these relatively high temperatures for producing snow or ice, some sprayed water droplets fail to solidify before reaching the ground.

[0005] Furthermore, the snow produced by such spray heads falls very quickly near the base of the pole and can then form a snowdrift. It is then necessary to move the snow produced with a snow groomer, or some other type of snow-smoothing equipment, to achieve optimal distribution of the snow thus produced on a section of a ski slope.

[0006] Document WO 2017 / 141144 A2 discloses a snow-producing spray head comprising a jacket and nozzles (5) for spraying pressurized water. The jacket carries the water, via one or more internal channels (4), from a pressurized water supply to the nozzle(s) (5). This document also describes a through-hole (2) and a ventilation device (105) allowing air to flow through the through-hole (2), which has an upstream and a downstream orifice (3) near which the nozzles (5) are arranged.

[0007] However, according to document WO 2017 / 141144 A2, the ventilation device (105) is in the form of a bladed fan (107). In practice, such a fan (107) generally includes an electric motor that must be connected to an electrical network to provide it with power. Furthermore, the rotation of such a rotating element can be blocked by ice, thus preventing any snow production.

[0008] It may be necessary to use heating devices on the head to melt the ice preventing the fan from rotating.

[0009] Furthermore, the airflow generated by such a fan is insufficient to circulate the water droplets for long enough in the surrounding air. This airflow is also, at best, at ambient temperature, or perhaps even higher than ambient temperature when heated by the electric motor driving the fan blades or by heating elements in the fan head to prevent it from seizing up. The resulting airflow is therefore insufficient to guarantee snow production in milder temperatures, particularly between -5°C and 0°C, and to disperse the snow over a wide and relatively distant area.

[0010] Document FR 2 617 273 A1 describes a snow cannon for the production of artificial snow. Such a cannon also includes a mixing chamber (7) into which water and air are injected. Compressed air is injected through a primary air injection nozzle (6) located downstream of a water inlet nozzle (2).

[0011] The air injection nozzle (6) can be of adjustable size and connect an annular chamber (5) with the mixing chamber (7).

[0012] As depicted in the figure 2 , the downstream edge of the annular slot is in the form of a cylindrical portion and extends into a spray conduit (12) having a diameter restriction at its downstream end.

[0013] Document WO 99 / 40381 A1 relates to a spray head for producing snow. Furthermore, this document describes the head as having a jacket and nozzles (11) for spraying pressurized water. This jacket allows water to be conveyed, via one or more internal channels (15, 16, 17), from a pressurized water supply to the nozzle(s) (11).

[0014] It also describes a central cavity (39) and a ventilation device allowing air to circulate through the central cavity (39) which has an upstream orifice and a downstream orifice near which the nozzles (11) are arranged.

[0015] In addition, such a ventilation device includes a central nozzle (35) allowing air brought under pressure through a channel (30) to be sprayed into the central cavity (39).

[0016] US document 3,795,367 A relates to a ventilation device for generating airflow by means of an annular slit implementing a Coanda effect.

[0017] Document US10039944 B2 reveals a spray head comprising water spray nozzles located inside a through-hole.

[0018] US4634050 A describes a spray head in which the water spray nozzles are mounted around the periphery of the outlet of a through-hole.

[0019] The present invention aims to provide a spray head designed to overcome the limitations mentioned above. An objective of the invention is therefore to provide a spray head capable of producing snow in relatively mild temperatures, particularly between -5°C and 0°C, potentially dispersing it over a wide area relatively far from the pole on which such a spray head can be mounted.

[0020] The invention therefore relates to a spray head comprising a sleeve and at least one nozzle, the sleeve comprising at least one conduit for connecting the at least one nozzle to a pressurized water supply, the at least one nozzle being configured to spray pressurized water into the surrounding air, this spray head comprising a through opening and a ventilation device configured to circulate the surrounding air through the through opening in a direction of circulation D1 between an upstream orifice and a downstream orifice of the through opening, the at least one nozzle being arranged on the downstream side of the through opening to allow the sprayed pressurized water to be carried along by a flow of surrounding air expelled from the downstream orifice.

[0021] According to the invention, the ventilation device is remarkable in that it has an annular slot configured to be connected to a pressurized air supply and to generate a pressurized airflow in the through opening, the annular slot being circumferentially delimited by an upstream edge arranged on an upstream side of the annular slot and by a downstream edge arranged on a downstream side of the annular slot, the upstream side and the downstream side being respectively defined according to the direction of circulation D1 of the surrounding air in the through opening, the downstream edge having a convex shape.

[0022] In other words, the through opening can be made entirely or partially inside the shirt.

[0023] Furthermore, the ventilation device lacks a blade rotating around an axis located inside the through-hole. This ventilation device nevertheless generates an airflow entering the through-hole from the surrounding environment via an upstream orifice and exiting through a downstream orifice. This airflow is referred to as the "surrounding airflow" for convenience, to distinguish it from the pressurized airflow injected through the annular slot.

[0024] The annular cleft can be located between the upstream and downstream orifices depending on the direction of flow.

[0025] Furthermore, the specific shape of the downstream edge allows the pressurized airflow exiting the annular slot to be attracted and follow a curve along this downstream edge. The pressurized airflow injected through the annular slot into the through-hole then generates a low-pressure area inside the through-hole.

[0026] Such a pressure drop then allows, through the so-called "Coanda effect," the circulation of the surrounding airflow in the direction of flow D1 within the through-hole by drawing in surrounding air located outside the spray head. The surrounding airflow, drawn in by the pressurized air injected through the annular slot, enters the through-hole through the upstream orifice and exits through the downstream orifice.

[0027] Furthermore, the term "annular slot" refers to a circumferential opening, that is, one that describes a closed curve surrounding a section of the through-hole. Such an annular slot also has a maximum width, measured between the upstream and downstream edges, of a few millimeters, for example, a width between 0.1 mm and 0.7 mm. The nozzle(s) are arranged on the downstream side of the through-hole to allow the sprayed water droplets to be carried, deflected, or accelerated by the surrounding airflow expelled from the through-hole. In practice, some nozzles may be arranged around the periphery of the downstream orifice.

[0028] Furthermore, at the annular slit, the pressurized air in the through-hole expands. This expansion is accompanied by a significant temperature drop in the pressurized air. Consequently, the surrounding airflow circulating through the through-hole is also cooled by a few degrees as it mixes with the pressurized airflow, which is cooler than the surrounding air. In practice, the temperature of the surrounding airflow circulating through the through-hole can be lowered by at least one degree Celsius, and possibly even two degrees Celsius, as it passes through the opening.

[0029] Consequently, such a release of pressurized air in the through opening makes it possible to promote snow production at relatively high temperatures, for example between -5°C and 0°C.

[0030] Furthermore, the surrounding airflow circulating through the through-orifice carries the sprayed water droplets much farther than with a spray head lacking a ventilation device. Injecting a pressurized airflow then increases the time these water droplets spend aloft. This increases the duration of heat exchange between the water droplets and the surrounding air, and improves the freezing of the water droplets. Consequently, at the same temperature, a spray head according to the invention can produce a greater quantity of snow than a spray head without a ventilation device.

[0031] Furthermore, the head is then devoid of rotating moving parts, and therefore no heating means are necessary to prevent these moving parts from becoming blocked by ice. The surrounding airflow circulating through the opening is thus not heated by the operation of a motor or by any heating devices.

[0032] The ventilation device is configured to be connected to the pressurized water supply, the ventilation device allowing the surrounding airflow circulating through the through opening to be mixed with water droplets.

[0033] In other words, water droplets can be directly sprayed and incorporated into the pressurized airflow exiting the annular slot of the ventilation device. Furthermore, these water droplets sprayed by the ventilation device via the pressurized airflow can have a cross-sectional area ranging from 30 µm (micrometers) to 200 µm. In comparison, water droplets sprayed using the nozzle(s) are, for example, larger and can have a cross-sectional area ranging from 0.6 mm (millimeters) to 2 mm (millimeters). Thus, when connected to a pressurized water supply, the ventilation device can directly generate snowflakes or ice crystals.These flakes are in fact obtained by a change of state of water droplets initially in liquid state present in the pressurized airflow and then mixed with the surrounding airflow.

[0034] In practice, the spray head may include an internal nozzle, a conduit arranged in fluidic communication with the pressurized water supply and a chamber arranged in fluidic communication with the pressurized air supply as well as with the internal nozzle and with the annular slot, the internal nozzle having a bore opening into the chamber and allowing pressurized water to be injected into the chamber.

[0035] Consequently, the jacket may have a chamber in which pressurized water and pressurized air mix. The water is then diffused as fine droplets with the pressurized air into the through-hole via the annular slot. The chamber where the mixing takes place is thus in fluidic communication with the annular slot by means of at least one conduit. For example, such a conduit is provided in the jacket and / or in a hose extending between the jacket and the ventilation device, or even in a body of the ventilation device, the body being attached to the jacket.

[0036] Furthermore, the ventilation device can be formed according to different embodiments conforming to the invention.

[0037] Thus, according to a first embodiment of the invention, the ventilation device may include a deflector forming the upstream orifice of the through opening, the upstream edge being formed by the deflector and the downstream edge being formed by the sleeve.

[0038] In other words, according to this first example, the ventilation system can be formed in part by a portion of the spray head's casing. The deflector is then attached to this portion of the casing and constitutes another part of the ventilation system. In this case, the chamber can communicate directly with the annular slot by means of at least one duct provided in the casing.

[0039] Such a deflector can also have a flared, convex shape, creating a restriction on airflow. This deflector shape also contributes, through the Venturi effect, to increasing the flow rate of surrounding air captured by the ventilation system.

[0040] The deflector is then secured to the sleeve via reversible fastening means, such as screws or nuts, or via additional snap-on means for example.

[0041] According to a second embodiment of the invention, the ventilation device may comprise a body and a cover, the cover forming the upstream orifice of the through opening, the upstream edge being formed by the cover cooperating in a type of embedment connection with the body and the downstream edge being formed by the body.

[0042] Such a second example corresponds to an independent ventilation device attached to the spray head casing. In this case, the ventilation device may be a standardized and / or commercially available unit. The chamber may communicate with the annular slot via at least one hose, one end of which is connected to the casing and the other to the body of the ventilation device.

[0043] As with the deflector in the first embodiment, such a cover in the second example can also have a flared convex shape, creating a restriction on the passage of ambient air through the opening. This shape of the cover also allows, through the Venturi effect, an increase in the flow rate of ambient air captured by the ventilation system.

[0044] The body is then secured to the casing using reversible fastening methods, such as screws or nuts, or alternatively, snap-on fasteners. Similarly, the cover is also secured to the body using reversible fastening methods, such as screws or nuts, or alternatively, snap-on fasteners.

[0045] According to the invention, the spray head comprises a first stage of at least two nozzles and a second stage of at least two nozzles, the spray head having a longitudinal direction D2, the through opening being arranged between the first stage and the second stage being along the longitudinal direction D2.

[0046] In other words, when the spray head is attached to a pole, the at least two nozzles of the first stage are located above the through-hole, while the at least two nozzles of the second stage are located below the through-hole. The first and second stages, each with at least two nozzles, are thus arranged on either side of the opening.

[0047] In practice, the sleeve may include at least two pipes connecting the first floor and the second floor, the at least two pipes being arranged respectively on either side of the through opening, each of the at least two pipes being oriented parallel to the longitudinal direction D2.

[0048] Thus, the at least two pipes allow pressurized water to be conveyed from a conduit or nozzle on the second floor to a conduit or nozzle on the first floor. The at least two pipes are advantageously arranged parallel to each other within the casing, or may even be formed by perforations. Once the perforations are made in the casing, plugs can optionally be added to close any openings in the pipes leading to the outside environment.

[0049] In addition, the spray head may include a third stage of at least two nozzles, the second stage being arranged between the through opening and the third stage in the longitudinal direction D2.

[0050] In other words, when the spray head is fixed on a pole, the at least two nozzles of the second stage can be located above the at least two nozzles of the third stage.

[0051] Advantageously, the at least two nozzles of the first stage can have four first nozzles, the at least two nozzles of the second stage can have four second nozzles and the at least two nozzles of the third stage can have four third nozzles for example.

[0052] Consequently, such a spray head can, for example, comprise a total of twelve nozzles arranged in groups of four across three levels. The individual nozzles can advantageously have distinct orientations to distribute the artificial snow over a large area of ​​a ski slope.

[0053] In addition, all or some of the nozzles on a given level can be blocked by means of caps attached to these nozzles. Such an arrangement can, in particular, temporarily reduce the quantity and / or the area over which snow is produced.

[0054] Furthermore, the through opening may have an oblong shape, at least in a plane perpendicular to the direction of traffic D1.

[0055] In other words, the through opening can have a significantly elongated shape along the longitudinal direction D2. Such an arrangement thus allows for a large air passage area while limiting one dimension in width of the jacket.

[0056] Furthermore, such a dimension in width of the shirt can be measured in any plane perpendicular to the longitudinal direction D2 and is relatively constant along this longitudinal direction D2.

[0057] The invention and its advantages will become apparent in more detail in the following description, with illustrative examples given by reference to the attached figures which represent: there figure 1 , a first perspective view according to a first example of the embodiment of a spray head according to the invention, the figure 2 , a second perspective view according to the first example of an embodiment of a spray head according to the invention, the figure 3 , a third perspective and cross-sectional view according to the first example of an embodiment of a spray head according to the invention, the figure 4 , a fourth perspective and cross-sectional view of a detail of the spray head according to the first embodiment, in accordance with the invention, the figure 5 , a fifth perspective and cross-sectional view according to the first embodiment of a spray head according to the invention, the figure 6 , a sixth perspective view according to a second embodiment of a spray head according to the invention, and the figure 7 , a cross-sectional view according to the second example of an embodiment of a spray head according to the invention.

[0058] Elements present in several separate figures are assigned a single reference.

[0059] As previously mentioned, the invention relates to a spray head for producing snow or ice from fine water droplets sprayed into the air. This spray head is advantageously designed to be mounted high on a pole, for example, at the edge of a ski slope.

[0060] In addition, various examples of spray head designs can be considered and are described below.

[0061] Thus, a first example of the realization of a spray head is as shown in the figures 1 à 5 and a second example of the realization of a spray head is as shown in the figures 6 And 7 .

[0062] Furthermore, in any embodiment, such a spray head 1, 11 includes a sleeve 2, 12 and at least one nozzle 3, 4, 5, 6, 13, 14, 15, 16, 13', 14', 15', 16' allowing the water droplets to be sprayed into the surrounding air and thus producing snow when the temperature of the surrounding air permits.

[0063] The sleeve 2, 12 then includes at least one pipe 7, 17 configured to connect, via fluidic communication, the nozzle(s) 3-6, 13-16, 13'-16' to a pressurized water supply 10. Such a pressurized water supply 10 may include a pump or a booster unit and piping. The pump or booster unit then allows water to be pumped from, for example, a reservoir, lake, aquifer, or river and its pressure increased. The piping, in turn, allows the pressurized water to be transported to one or more spray heads. The pressurized water supply 10 may also include valves for controlling the flow of pressurized water to or from the spray heads.

[0064] In addition, when a valve controls a stop of the circulation of pressurized water in the spray heads, drains can advantageously allow the water contained between the spray head and the valve to be purged.

[0065] Furthermore, according to the invention, the spray head 1, 11 includes a through opening 8, 18 through which ambient air can circulate. To this end, the spray head 1, 11 also includes a ventilation device 9, 19 arranged at the through opening 8, 18, allowing ambient air to circulate in a direction D1 within the through opening, for example, at a predetermined ventilation speed.

[0066] In addition, such a ventilation device 9, 19 is for example bladeless and is connected to a pressurized air supply 40. Such a pressurized air supply 40 may in particular include a compressor for compressing air to atmospheric pressure, a storage tank for storing pressurized air and conduits for conveying the pressurized air from the storage tank to one or more spray heads.

[0067] Furthermore, the ventilation device 9, 19 has an annular slot 20, 30 configured to be connected to the pressurized air supply 40 and to inject a flow of pressurized air into the through opening 8, 18. Such a flow of pressurized air then allows surrounding air to be drawn into the through opening 8, 18. A flow of surrounding air then passes through the through opening 8, 18 between an upstream orifice 27, 37 and a downstream orifice 22, 32 according to the direction of flow D1.

[0068] Furthermore, the annular slot 20, 30 is circumferentially delimited, namely on its entire perimeter, by an upstream edge 29, 39 arranged on an upstream side of the annular slot 20, 30 and by a downstream edge 21, 31 arranged on a downstream side of the annular slot 20, 30. In addition, the upstream side and the downstream side are respectively defined according to the direction of circulation D1 of the surrounding air in the through opening 8, 18.

[0069] Furthermore, the downstream edge 21, 31 has a convex shape that allows the pressurized airflow exiting the annular slot 20, 30 to be deflected towards an internal wall of the through-hole 8, 18. This convex shape of the downstream edge 21, 31 allows the pressurized airflow to generate a low-pressure area at the through-hole 8, 18. The surrounding air is then drawn in by this low pressure caused by the Coanda effect to which the pressurized airflow is subjected. This suction allows a flow of surrounding air to circulate through the through-hole 8, 18 in the direction of flow D1 from the upstream orifice to the downstream orifice.

[0070] Furthermore, such a ventilation device 9, 19 can advantageously be configured to be connected to the pressurized water supply 10 so as to spray fine water droplets directly by means of the ventilation device 9, 19 into the through opening 8, 18.

[0071] According to the first example of a spray head design shown in particular in figures 1 3 And 4 , the ventilation device 9 may include a deflector 26 forming the upstream orifice 27 of the through opening 8. In this case, the upstream edge 29 is also formed by the deflector 26 and the downstream edge 21 is formed by the sleeve 2.

[0072] Alternatively, according to the second example of spray head implementation shown in figures 6 And 7 The ventilation device 19 may comprise a body 33 and a cover 35, the cover 35 forming the upstream orifice 37 of the through opening 18. In this case, the upstream edge 39 is also formed by the cover 35 cooperating in a fixed-type connection with the body 33 and the downstream edge 31 is formed by the body 33. The annular slot 30 is therefore located axially between the body 33 and the cover 35.

[0073] Furthermore, regardless of the embodiment example, the annular slot 20, 30 can be advantageously arranged in a restriction of the cross-section of the through opening 8, 18.

[0074] Furthermore, regardless of the embodiment, such a spray head 1, 11 may include an internal nozzle 23, 43 as shown in the figure 3 but not limited to this first example of implementation. Such an internal nozzle 23, 43 is then arranged in fluidic communication with the pressurized water supply 10, for example via the pipe(s) 7, 17, and a chamber 24, 34. The chamber 24, 34 is also in fluidic communication with the pressurized air supply 40 and with the annular slot 20, 30. This internal nozzle 23, 43 advantageously has a bore 25, 45 opening into the chamber 24, 34 and allowing pressurized water to be sprayed into the chamber 24, 34. The pressurized water injected by the nozzle 25, 45 and the pressurized air from the pressurized air supply 40 are then mixed in the chamber 24, 34 and expelled together through the annular slot 20, 30 into the through opening 8, 18.

[0075] According to the first embodiment, chamber 24 can then communicate directly with the annular slot 20 by means of at least one conduit 28 provided in the sleeve 2. Alternatively, according to the second embodiment and as shown in the figure 7 , chamber 34 can communicate indirectly with annular slot 30 by means of at least one hose 38 extending outside the sleeve 12. Such a hose 38 can in fact extend between the sleeve 12 and the body 33 of the ventilation device 19.

[0076] Similarly, as represented in figures 2 And 6And whatever the embodiment, the spray head 1, 11 comprises a first stage 101, 111 of at least two nozzles 3-6, a second stage 102, 112 of at least two nozzles 13-16 and may comprise a third stage 103, 113 of at least two nozzles 13'-16'. Along the longitudinal direction D2, the through opening 8, 18 is then arranged between the first stage 101, 111 and the second stage 102, 112. While the second stage 102, 112 is itself interposed between the through opening 8, 18 and the third stage 103, 113.

[0077] The through-hole 8, 18 is therefore arranged in the sleeve 2, 12 between the first stage 101, 111 and the second stage 102, 112 in such a way as to allow the airflow passing through the through-hole 8, 18 to entrain, deflect, accelerate, and / or cool the water droplets sprayed by the various nozzles. The water droplets can then be more quickly transformed into snow or ice flakes and can also be propelled away from the spray head, thus improving their distribution on the ski slope.

[0078] Furthermore, as represented in the figure 5 , the sleeve 2, 12 may include at least two pipes 105, 106 connecting the first floor 101, 111 and the second floor 102, 112. As represented, these pipes 105, 106 may be arranged respectively on either side of the through opening 8, 18.

[0079] Furthermore, such a through opening 8, 18 can present, at least in a plane perpendicular to the direction of circulation D1, an oblong shape. This oblong shape is then substantially elongated along the longitudinal direction D2 oriented from the first floor 101, 111 by at least two nozzles towards the second floor 102, 112 by at least two nozzles.

[0080] Furthermore, such an oblong shape allows for a large air passage cross-section while limiting one dimension in width of a shirt 2, 12.

Claims

1. Spray head (1, 11) comprising a jacket (2, 12) and at least one nozzle (3, 4, 5, 6, 13, 14, 15, 16, 13', 14', 15', 16'), said jacket (2, 12) comprising at least one pipe (7, 17) for connecting said at least one nozzle (3-6, 13-16, 13'-16') to a pressurised water supply (10), said at least one nozzle (3-6, 13-16, 13'-16') being configured to spray pressurised water into the surrounding air, said spray head (1, 11) comprising a through opening (8, 18) and a ventilation device (9, 19) configured to circulate the surrounding air through said through opening (8, 18) according to a direction of circulation D1 between an upstream orifice (27, 37) and a downstream orifice (22, 32) of said through opening (8, 18), said at least one nozzle (3-6, 13-16, 13'-16') being arranged on the side of said downstream orifice (22, 32) of said through opening (8, 18) to allow said sprayed pressurised water to be entrained by a flow of surrounding air expelled from said downstream orifice (22, 32), said ventilation device (9, 19) having an annular slot (20, 30) configured to be connected to a pressurised air supply (40) and to generate a flow of pressurised air in said through opening (8, 18), said annular slot (20, 30) being delimited circumferentially by an upstream edge (29, 39) arranged on an upstream side of said annular slot (20, 30) and by a downstream edge (21, 31) arranged on a downstream side of said annular slot (20, 30), said upstream side and said downstream side being respectively defined according to said direction of circulation D1 of the surrounding air in said through opening (8, 18), said downstream edge (21, 31) having a convex shape, characterised in that said spray head (1, 11) comprises a first stage (101, 111) of at least two nozzles (3-6) and a second stage (102, 112) of at least two nozzles (13-16), said spray head (1, 11) having a longitudinal direction D2, said through opening (8, 18) being arranged between said first stage (101, 111) and said second stage (102, 112) in said longitudinal direction D2, each of said at least two nozzles (3-6) of said first stage (101, 111) being arranged above said through opening (8, 18) according to said longitudinal direction D2 and each of said at least two nozzles (13-16) of said second stage (102, 112) being arranged below said through opening (8, 18) according to said longitudinal direction D2.

2. Spray head according to claim 1, characterised in that said ventilation device (9, 19) is configured to be connected to said pressurised water supply (10), said ventilation device (9, 19) making it possible to mix with drops of water said flow of surrounding air circulating through said through opening (8, 18).

3. Spray head according to claim 2, characterised in that said spray head (1, 11) comprises an internal nozzle (23, 43), a conduit arranged in fluid communication with said pressurised water supply (10) and a chamber (24, 34) arranged in fluid communication with said pressurised air supply (40) as well as with said internal nozzle (23, 43) and with said annular slot (20, 30), said internal nozzle (23, 43) having a bore (25, 45) opening into said chamber (24, 34) and making it possible to inject said pressurised water into said chamber (24, 34).

4. Spray head according to any one of claims 1 to 3, characterised in that said ventilation device (9) comprises a deflector (26) forming said upstream orifice (27) of said through opening (8), said upstream edge (29) being formed by the deflector (26) and said downstream edge (21) being formed by said jacket (2).

5. Spray head according to any one of claims 1 to 3, characterised in that said ventilation device (19) comprises a body (33) and a cover (35), said cover (35) forming said upstream orifice (37) of said through opening (18), said upstream edge (39) being formed by a cover (35) cooperating in an interlocking connection with said body (33) and said downstream edge (31) being formed by said body (33).

6. Spray head according to claim 1, characterised in that said jacket (2, 12) comprises at least two conduits (105, 106) connecting said first stage (101, 111) and said second stage (102, 112), said at least two conduits (105, 106) being arranged respectively on either side of said through opening (8, 18), each of said at least two conduits (105, 106) being oriented parallel to said longitudinal direction D2.

7. Spray head according to claim 6, characterised in that said spray head (1, 11) comprises a third stage (103, 113) of at least two nozzles (13'-16'), said second stage (102, 112) being arranged between said through opening (8, 18) and said third stage (103, 113) according to said longitudinal direction D2.

8. Spray head according to claim 7, characterised in that said at least two nozzles (3-6) of said first stage (101, 111) comprise four first nozzles (3-6), said at least two nozzles (13-16) of said second stage (102, 112) comprise four second nozzles (13-16) and said at least two nozzles (13'-16') of said third stage (103, 113) comprise four third nozzles (13'-16').

9. Spray head according to any one of claims 1 to 8, characterised in that said through opening (8, 18) has, at least in a plane perpendicular to said direction of circulation D1, an oblong shape.