Ozonated water spraying device for agricultural use

Abstract

The invention relates to a device for spraying ozonated water in an agricultural setting. The device comprises a collar defining a distribution opening (4) for the combined distribution of water and ozone. The water is sprayed by a nozzle (10) recessed from the opening. The nozzle is supplied by a reservoir (7) integrated with the device. The gaseous ozone is distributed by a gas inlet (22) connected to a gas production and / or storage device (9, 13) also integrated with the device. The gas inlet is also recessed within the collar, such that the collar defines a containment chamber (28, 29) for the emitted gaseous ozone around the sprayed liquid, thereby enriching the sprayed liquid with dissolved ozone. Figure 6 (for the abstract)

Description

Title of the invention: Device for spraying ozonated water in agricultural environments technical field

[0001] The present invention relates to a spraying device, particularly intended for use outdoors, especially in agricultural settings, on hectares of crops to be treated, or indoors. The advantage of the invention is its ability to spray a liquid containing a gas or gaseous solute, while limiting the desorption of the gaseous solute or gas from the sprayed liquid. More specifically, this device can spray ozone-containing water via a nozzle, in order to carry out a treatment, whether phytosanitary for crops or chemical for treating a surface. Technological background

[0002] In the prior art, ozonated water diffusion devices for sterilization, disinfection, and deodorization in industrial settings and in closed, controlled-atmosphere environments are known. In particular, documents US5431861, US6,076,748, and JP2008229491 describe such devices.

[0003] On an experimental scale, ozonated water is known for its effectiveness in controlling the development of certain pathogens. Ozonated water could be an alternative to phytosanitary treatments based on synthetic products from the chemical industry. Indeed, ozonated water offers a major ecological advantage in that the persistence of the ozone molecule is very low, and it decomposes into oxygen that is neutral for the environment.

[0004] However, since the half-life of gaseous ozone in air at 20°C is 3 days, while the half-life of ozone dissolved in water at 20°C is 20 minutes, ozonated water has never been used effectively in agriculture for plant protection treatments. Indeed, in open air, it is not possible to force gaseous ozone to remain in contact with the crops being treated, due to weather conditions and wind. Furthermore, the solubilization of ozone in aqueous solution reduces its half-life to approximately 20 minutes at ambient temperature, which remains problematic. In fact, spraying ozonated water through a nozzle towards a target crop is associated with significant desorption of ozone from the sprayed droplets, rendering this action ineffective. Summary of the invention

[0005] The object of the invention is to propose a solution adaptable to the agricultural environment and whose efficiency is demonstrated in the phytosanitary treatment of plants concerned. The interest of the invention is to propose a technical solution which makes it possible to maintain an effective ozone concentration in a sprayed liquid either by promoting the absorption of ozone in this liquid or by limiting its desorption.

[0006] The advantage of the invention is that it allows the atomization of a liquid in a gaseous environment in order to increase the absorption of the gaseous solute or to limit its desorption. These atomization conditions correspond to a difference in velocity between the ejected liquid and the gas diffused around the ejected liquid, resulting in friction occurring on the surface of the ejected liquid. This friction induces the transformation of the liquid jet from a liquid film into ribbons, then into ligaments which subsequently break into relatively spherical particles to produce a cloud of droplets.

[0007] The invention consists of promoting the dissolution of the gas as a gaseous solute in the ejected liquid, particularly when the liquid is still predominantly in the form of a jet, film, or strands, and before the majority of the liquid is in the form of droplets. The invention also aims to limit the desorption of the gaseous solute (ozone) already dissolved in the ejected liquid, particularly when this liquid is still predominantly in the form of a jet, film, or strand. The invention also consists of limiting the presence of gas other than the gaseous solute around the liquid when the liquid is still predominantly in the form of a jet, film, or strands. The invention promotes the presence of gas around the sprayed liquid in the form of a jet, film, or strands, in order to increase the proportion of gaseous solute in the liquid.

[0008] The invention relates to a spraying device, in particular for spraying ozonated water in agricultural environments, the device comprising - a joint liquid and gas distribution opening, - a nozzle intended to be connected to a liquid reservoir to be sprayed, - a gas inlet of a gas production and / or storage device, and a collar surrounding the nozzle and the gas inlet, such that an edge of this collar defines the distribution opening of the device, and a spray orifice of the nozzle is at a setback distance (dr) in the collar relative to this distribution opening, the collar defining a containment chamber for the gas emitted by the gas inlet, the containment chamber extending between the spray orifice and the distribution opening.

[0009] In particular, the difference in the liquid emission velocity from the spray orifice is between 50 and 1500 times, preferably between 100 and 300 times, greater than the gas distribution velocity from the gas inlet, so that the liquid can be predominantly in the form of a jet, film, or ligaments in the collar. In particular, a liquid distribution velocity is on the order of 5 to 15 m / s, while a velocity The gas distribution rate is on the order of 1 to 10 cm / s.

[0010] Preferably, the spray orifice can distribute the liquid according to a spatially distributed spray in at least one plane, such that a width of the opening measured in this plane and orthogonally to a spray axis Y of the nozzle represents between 80% and 140%, and more particularly between 95% and 120% of a spray width in this same plane for a spray produced by said nozzle without its collar, this spray width being measured at a distance from the spray orifice equal to the withdrawal distance.

[0011] More particularly, the spray orifice can distribute the liquid according to a spray spatially distributed in at least one plane and having a spray thickness transverse to this plane such that a thickness of the opening measured transverse to this plane represents more than 100% and less than 140% of the spray thickness transverse to this same plane for a spray produced by said nozzle without its collar, the spray thickness being measured at a distance from the spray orifice equal to the withdrawal distance.

[0012] Advantageously, the spray orifice can distribute the liquid according to a spray comprising a portion in the form of a liquid film having a continuous surface such that a length of the continuous surface of this film is measured along a spray axis of the nozzle represents between 40 and 120% of the withdrawal distance.

[0013] In particular, the spray orifice may be in the form of a longitudinal slit along an elongation axis Z, and in this case the distribution opening of the device preferentially has a main elongation axis parallel to the axis of the slit.

[0014] In particular, the gas inlet can be positioned behind the spray orifice relative to the distribution opening. Such a configuration prevents the formation of turbulence at the spray orifice, allowing the gas to be distributed in an annular volume and diffuse in an annular manner around the nozzle.

[0015] In particular, for homogeneous gas diffusion in the containment chamber, the device may include at least two equally spaced gas inlets, either diametrically opposed when there are only two inlets, and for example supplied with an identical gas sourced from the same gas production and / or storage device.

[0016] Preferably, the volume of the containment chamber can be parallelepiped-shaped.

[0017] The advantage of the invention is to provide a collar that allows for the definition of a containment chamber. In fact, the configuration of the nozzle and the collar are jointly determined so that the spray orifice sprays a spray whose nominal volume of the surface area enveloping this spray, inside the collar, represents a volume less than 5% of the internal volume of the collar.

[0018] Advantageously, the distribution opening is unique, and the collar is formed by a continuous wall, so that all gases and liquids contained in the containment chamber can be controlled.

[0019] The invention also relates to a method for designing a spraying device in which - A nozzle is selected that is capable of emitting a spray of liquid distributed spatially according to an opening angle in a plane and a radial thickness transverse to that plane. - A liquid flow rate is determined at the nozzle, in order to determine a gas flow rate based on this liquid flow rate. - a collar depth is determined based on the opening angle and radial thickness of the nozzle spray.

[0020] The invention also relates to an assembly for treatment by a solute dissolved in a liquid comprising a spraying device according to the invention, a reservoir of liquid to be sprayed, a similar device for the production and / or storage of the gas of interest to be diffused jointly with the liquid by the spraying device, the gas production and / or device comprising a bypass to the reservoir to enrich the liquid contained in the reservoir with gaseous solute, so that the liquid may contain a non-zero proportion of dissolved gaseous solute before its spraying. Brief description of the figures

[0021] The following description, with reference to the accompanying drawings, given by way of non-limiting examples, will clearly explain what the invention consists of and how it can be implemented. In the accompanying figures:

[0022] [Fig-1] Fig. 1 represents a diagram of agricultural spraying of a treatment phytosanitary on a vine, in which a spraying by a cloud of droplets is schematically represented, and a proportion of gas in this cloud of droplets is also schematically represented by a density of black dots in each droplet;

[0023] [Fig.2a] Fig.2a represents a first distribution modeling device of a liquid containing a proportion of dissolved gas;

[0024] [Fig. 2b] Figure 2b represents a graph with proportions measured in gas dissolved in the liquid distributed by a device according to [Fig.2a], as a function of a distance between the measurement point and a spray orifice of this liquid by a nozzle of the device according to [Fig.2a];

[0025] [Fig. 3a] Fig. 3a shows a view of a spray dispersed by a nozzle of a spraying device according to the invention

[0026] [Fig. 3b] [Fig. 3b] shows a view of the spray of [Fig. 3a] from a viewing angle perpendicular to that of [Fig.3a];

[0027] [Fig.4a] Fig.4a represents a second modeling device for the distribution of a liquid comprising a proportion of dissolved gas according to a spraying device according to the invention;

[0028] [Fig.4b] Fig.4b represents a graph with proportions measured in gas dissolved in the liquid distributed by a device according to Fig.4a, as a function of a distance between the measurement point and a spray orifice of this liquid by a nozzle of the device according to Fig.4a;

[0029] [Fig.5] Fig.5 represents a perspective view of a spraying device according to the invention;

[0030] [Fig.6] The [Fig.6] represents a longitudinal cross-sectional view of a spraying device according to the [Fig.5];

[0031] [Fig.7] The [Fig.7] represents a perspective view of a spraying device according to an alternative embodiment of the invention;

[0032] [Fig.8] The [Fig.8] represents a longitudinal cross-sectional view of a spraying device according to the [Fig.7];

[0033] [Fig.9] The [Fig.9] represents a perspective view according to a partial longitudinal section of a spraying device according to the [Fig.7]. Description of method(s) of implementation

[0034] In the figures, and unless otherwise specified, identical elements shall bear the same reference symbols.

[0035] In agriculture, as shown in [Fig. 1], an agricultural sprayer 1 is generally a mobile device. Since crops are organized to facilitate the mechanization of agricultural work, the agricultural sprayer 1 is equipped with means of movement 2, such as wheels 2 in the example of [Fig. 1], to facilitate the movement of the sprayer along a planting 3 to be treated. In particular, the agricultural sprayer 1 is towed along furrows, each containing one of the plantings, such as vines, to be treated. The agricultural sprayer 1 is intended to disperse a plant protection product, preferably in a homogeneous dose, as it moves along the crops.

[0036] To protect the crops, the sprayer is kept at a distance from these crops during its movement, such that a distance "d" between a distribution opening 4 of the device 1 and a foot 5 of the planting 3, measured transversely to the axis of movement of the device 1, is preferably greater than the value d less half of a theoretical average width lth of the planting 3, this theoretical width being measured transversely to the axis of movement of the device 1. A distribution axis Y of the sprayer 1 is oriented perpendicular to a rolling direction X of this sprayer 1. The spraying is lateral to the movement.

[0037] To ensure the homogeneous application of the plant protection product, the agricultural sprayer is configured to produce a cloud of droplets 6, the drops of which are primarily propelled to a distance between [d - 2lth; d + 2lth]. At this distance, the lateral propulsion force of the droplets is neutralized by their weight, and they are then deposited by gravity onto the crop 3. The agricultural sprayer 1 may include means for orienting the distribution opening 4 so that the distribution axis Y can be modified and is not necessarily oriented parallel to the ground on which the wheels are in contact.

[0038] The sprayer 1 is designed to allow the simultaneous distribution of liquid and gas, and also of gas dissolved in the liquid. The sprayer 1 includes a first connection means to a liquid reservoir 7. This liquid reservoir 7 can be supported by a chassis 8 on which the wheels 2 are mounted. The sprayer 1 includes a second connection means for being connected to a gas production and / or storage device 9, this device being a gas cylinder in which the gas is compressed. The gas production and / or storage device 9 is also supported by the chassis 8.

[0039] The liquid reservoir 7 contains water, or ozonated water having a non-zero proportion of ozone. The gas cylinder 9 contains gaseous ozone. Under ambient conditions, ozone tends to decompose naturally into dioxygen.

[0040] Figure 2a represents a device for modeling a proportion of ozone (03) in a liquid film 11 sprayed by an ozonated water preparation and spraying device via a nozzle 10, the ozone being already dissolved in the liquid to be sprayed. In this model, the nozzle 10 is supplied by a connection means 12 to a liquid reservoir 7, in particular water. This reservoir 7 is itself supplied by a line 18 with gas provided by an ozone generator 13. The ozone generator 13 can continuously enrich the liquid with ozone in order to control and maintain a proportion PI of ozone dissolved in the liquid to be sprayed by the nozzle.

[0041] Figure 2b shows an evolution of the proportion P2 of ozone dissolved in the film 11, this proportion P2 is a function of a distance D of the measurement relative to the nozzle 10 along a distribution axis Y. This modeling confirms the observations concerning the inefficiency of a treatment with sprayed ozonated water insofar as from the first few centimeters at the exit of a spray orifice 14 of the nozzle 10, a very clear decrease in the proportion of dissolved ozone is observed in the film 11. And at a distance D of 1 meter, the proportion P2 of ozone dissolved in the distributed liquid is divided by 20 compared to the proportion PI of ozone dissolved in the liquid of the reservoir 7.

[0042] Preferably, to obtain a film, the nozzle 10 has a spray orifice 14 in the form of a longitudinal slit along an axis Z, so that the jet is in the form of a film whose contours projected onto a plane containing the axis Z have a continuous surface 15 from the slit of the spray orifice, this continuous surface 15 being bordered by filaments 16 which terminate in droplets 17. The continuous surface 15 forms a liquid film 15. As shown in [Fig. 3b], which is a view perpendicular to that of [Fig. 3a], it can be seen that the continuous surface 15 is substantially flat over a distance DI measured from the spray orifice 14, and then undulates over a distance D2, to be predominantly in the form of droplets 17 beyond the distance D2.

[0043] The droplet cloud is thus formed at a cumulative distance of DI and D2 from the spray orifice 14. A continuous liquid film therefore exists over a cumulative distance of DI and D2. Over the distance D1, a thickness "e" of the film is represented [Fig. 3b]. This thickness e decreases as the distance from the spray orifice 14 at which the thickness is measured increases. The further the measurement is taken from the spray orifice, the thinner the film thickness. Indeed, the continuous surface 15 gradually diminishes until it forms the filaments 16 and the droplets 17.

[0044] The envelope surface of the spray atomized by the spray nozzle 14 encompasses the spatial environment in which the continuous surface 15, the filaments 16, and the droplets 17 are located at the outlet of the spray nozzle. Depending on the Y direction of spraying relative to the ground, the shape of this envelope surface changes under the effect of the gravitational forces acting on the droplets.

[0045] In [Fig.3a], the spray orifice distributes the liquid according to a spray with an opening angle a. The apex of the opening angle a is located upstream of the spray orifice 14. In view of the observation that from the first few centimeters at the exit of the spray orifice 14 of the nozzle 10, a very clear decrease in the proportion of dissolved ozone was observed in the film 11, the inventors have shown that this phenomenon could be circumscribed, and at least limited by the presence of a collar 20 around the sprayed liquid, this collar being arranged around the sprayed liquid from the first few centimeters around the exit of the spray orifice.

[0046] Figure 4a represents a model of a spraying device according to the invention. According to the invention, the spraying device 1, also called a sprayer, comprises a nozzle 10 for connection to a reservoir 7 by means of a connection 12. The nozzle is for distributing a liquid contained in the reservoir 7 through a spray orifice 14. In particular, according to one embodiment, the liquid is sprayed in the form of a film 11. In the invention, the device comprises a collar 20 which surrounds the nozzle 10 and the spray orifice 14 such that that an edge 21 of this collar 20 delimits an opening 4 of the spraying device.

[0047] According to the invention, the sprayer according to the invention 1 also includes a gas inlet 22, this inlet 22 being connected to a conduit 23 for connection to a gas generator 13 or a gas cylinder 9. Preferably the gas is compressed in the gas cylinder 9. The gas inlet 22 is disposed inside the volume delimited by the collar 20.

[0048] The collar 20 has a base 24 through which the nozzle body 10 passes, and a side wall 25 raised around the base 24. The side wall 25 has a bore 26 for receiving the gas inlet 22. As shown in [Fig. 5], the collar has two bores such as 26 for receiving two gas inlets such as 22. The two gas inlets 22 are diametrically opposed and are oriented so that their respective flows are directed along the same distribution axis W. The distribution axis W of the gas in the collar 20 intersects with the nozzle body 10, as shown in [Fig. 6]. According to the embodiment of [Fig.6], the two gas inlets 22 supply the collar 20 with gas upstream of the spray orifice 14, so that the distributed gas is located around the nozzle body and surrounds the spray sprayed by the spray orifice 14.In this configuration, a retraction distance dg from the gas inlets 22 relative to the opening 4 is greater than a distance between the spray orifice and the opening.

[0049] The nozzle body is cylindrical, and the bottom 24 and side wall 25 are shaped to define an annular volume around the nozzle body. The side wall has an internal annular restriction 27 such that the internal volume delimited in the collar comprises the annular volume 28 around the nozzle body and a cylindrical volume 29, in fluidic continuity with the annular volume 28. The spray orifice 14 is designed to open centrally, so that the spray orifice 14 is at every point equidistant from the internal annular restriction 27. The spray axis Y of the spray orifice 14 is substantially parallel to the main elongation axis of the collar 20.

[0050] Inside the collar 20, a liquid spray is distributed through the distribution orifice 14, and a gas is distributed through the gas inlet(s) 22. The device thus allows for the simultaneous distribution of liquid and gas. And as demonstrated experimentally, the presence of the collar contributes to a very significant improvement, as shown in [Fig. 4b], in the proportion of ozone dissolved in the liquid sprayed with a device according to the invention. Indeed, the presence of gaseous ozone in the first few centimeters at the outlet of the distribution orifice contributes to a very significant increase in the ozone dissolved in the sprayed liquid. The collar contributes to the formation of a containment chamber of the gaseous ozone around the liquid spray, and even better around the film of this spray.

[0051] The spray orifice is at a withdrawal distance "dr" from the opening 4. And as schematically represented, turbulence T is observed in the gaseous ozone due to an air suction phenomenon A at the distribution opening 4. The withdrawal distance is on the order of a few centimeters, for example between 4 and 10 cm.

[0052] This containment chamber makes it possible to triple the proportion P3 of dissolved gas in the sprayed liquid compared to a reference value PI, which corresponds to the proportion of dissolved gas in the liquid before spraying. Another advantage of the device according to the invention is that it allows for a significant enrichment in dissolved ozone and a limitation of the desorption phenomenon of dissolved ozone in the sprayed liquid. Thanks to the invention, at a distance D of 1 meter from the opening, this proportion P3 of dissolved ozone is equal to that of the liquid in the reservoir. This result makes it possible to improve the efficiency of phytosanitary treatments based on ozonated water thus distributed.

[0053] A device according to the invention, with a collar, demonstrates an efficiency 20 times greater than that of a simple device.

[0054] In particular, this containment chamber comprises the annular volume 28 and the frustoconical volume 29, reduced by the space occupied by the sprayed liquid. At a minimum, the containment chamber extends between the spray orifice 14 and the opening 4. Indeed, in alternative embodiments of a device according to the invention, the collar configuration may lack the frustoconical volume 28, since the gas inlets 22 are provided in the side wall 25 at a location situated between the opening 4 and the spray orifice 14.

[0055] The spray orifice distributes the liquid in a spray pattern having an envelope surface. In a case where the collar defines a frustoconical volume 29 with a circular cross-section, and where the envelope surface of the spray is also frustoconical with a circular cross-section, then the width of the spray and the width of the opening can be measured along any axis. However, when the nozzle 10 has a spray orifice 14 in the form of a longitudinal slot along a Z-axis, such that the spray is in the form of a film jet along the Y-axis perpendicular to this Z-axis, then the width of the spray pattern of this envelope surface and the width of the opening are measured along this Z-axis.In particular, the configuration of the nozzle 10 and the collar 20 is such that the width of the spray "1s", measured at a distance "dr" from the collarless spray orifice is between 80% and 140% of the width "lo" of the opening 4 along this Z axis.

[0056] When the film extends from the nozzle outlet in a plane containing the Z-axis, and forms a continuous surface 15 bordered by filaments 16 and ending in drops 17, the width “If” of the continuous surface 15, [Fig.3a], measured along the Z axis at a distance equal to the retraction distance dr of the spray orifice without a collar is between 40% and 120% of the width of the opening 4 along this Z axis. The cumulative distance DI and D2 can in particular represent between 40% and 120% of the retraction distance “dr”.

[0057] As can be seen in [Fig.5], the Z axis of the slit formed by the spray orifice is not necessarily parallel to the gas distribution axis W.

[0058] Perpendicular to the width measurements, when the nozzle 10 has a spray orifice 14 in the form of a longitudinal slot, a maximum thickness "Es" of the spray can be defined along an axis perpendicular to the Z axis. In this case, the opening 4 is preferably configured to have a slot shape, [Fig.7], of width "lo" and thickness "Eo", such that the maximum thickness "Es" of the spray, measured at a distance "dr" from the spray orifice without a collar, is between 80% and 140% of the thickness "Eo" of the opening 4 perpendicular to this Z axis.

[0059] The width and thickness measurements of the spray are carried out in the absence of the collar, because turbulence is more particularly observed in a portion corresponding to the length D2 of the spray, that in which the continuous surface of the sprayed liquid undulates, so that this turbulence locally modifies the dimensions of the spray observed in the collar, and can be modulated by the gas flow at the level of the gas inlets 22 determined in the confinement chamber.

[0060] When the width exceeds 100% of the opening width, a runoff phenomenon of some of the sprayed liquid is observed along the side wall. A preferred ratio between the width of the distribution opening lo and the spray width 1s is 95% to 120%.

[0061] In the variant of figures 7 to 9, where the opening defines a slit and where the spraying is done via a spray orifice provided with a slit, the gas inlets 22 are diametrically opposed along the axis of the slit, and are located set back from the opening 4, by a distance dg less than the setback distance dr of the spray orifice relative to the opening 4.

[0062] Optionally, the tank 7 can also be supplied by a line 18 with gas provided by an ozone generator 13 so that the distributed liquid is already enriched with dissolved ozone before even being sprayed and is additionally charged with dissolved ozone in the containment chamber.

Claims

Demands

1. Spraying device (1), particularly for spraying ozonated water in agricultural settings, the device comprising a combined liquid and gas distribution opening (4), a nozzle (10) intended to be connected to a reservoir (7) of liquid to be sprayed, a gas inlet (22) of a gas production and / or storage device (9, 13), and a collar (20) surrounding the nozzle and the gas inlet, such that an edge (21) of this collar defines the distribution opening of the device, and a spray orifice (14) of the nozzle is at a setback distance (dr) in the collar relative to this distribution opening, characterized in that the collar defines a containment chamber (28, 29) for the gas emitted by the gas inlet, the containment chamber extending between the spray orifice and the distribution opening.

2. Spraying device according to claim 1 characterized in that the nozzle has a liquid spraying velocity through the spray orifice, the gas production and / or storage device has a gas distribution velocity through the gas inlet, such that the liquid spraying velocity is between 100 and 300 times the gas distribution velocity.

3. Spraying device according to claim 1 or 2 characterized in that the spray orifice distributes the liquid according to a spatially distributed spray in at least one plane such that a width (lo) of the opening measured in this plane and orthogonally to a spray axis (Y) of the nozzle represents between 80% and 140%, and more particularly between 95% and 120% of a width (1s) of spray in this same plane for a spray produced by said nozzle without its collar, this spray width being measured at a distance from the spray orifice equal to the withdrawal distance (dr).

4. A spraying device according to any one of the preceding claims, characterized in that the spray orifice distributes the liquid in a spatially distributed spray pattern in at least one plane and having a spray thickness (Es) transverse to this plane such that a thickness of the opening (Eo) measured transversely to this plane represents more than 100%, in particular less than 140% of the thickness of spray transversely to this same plane for a spray produced by said nozzle without its collar, the thickness of spray being measured at a distance from the spray orifice equal to the withdrawal distance (dr).

5. Spraying device according to any one of the preceding claims characterized in that the spray orifice distributes the liquid according to a spray comprising a portion in the form of a liquid film (11), and in that a length of this film measured along a spray axis (Y) of the nozzle (10) represents between 40 and 120% of the withdrawal distance (dr).

6. Spraying device according to any one of the preceding claims characterized in that the spray orifice (14) forms a longitudinal slit along an elongation axis (Z), and the distribution opening (4) has a principal elongation axis parallel to the axis of the slit.

7. Spraying device according to any one of the preceding claims characterized in that the gas inlet is recessed in the collar relative to the distribution opening (4), this recess of the gas inlet (dg) being able to be greater than the withdrawal distance (dr).

8. Spraying device according to any one of the preceding claims characterized in that it comprises at least two equally spaced gas inlets connected to the same gas production and / or storage device (9).

9. Spraying device according to any one of the preceding claims characterized in that the spray orifice distributes the liquid according to a spatially distributed spray, such that the nozzle without its collar distributes a spray having a measured spray volume in a defined volume between the spray orifice and a retraction distance (dr) from this spray orifice, such that the spray volume occupies a volume less than 5% of an internal volume of the collar.

10. Spraying device according to any one of the preceding claims characterized in that the distribution opening is unique, and the collar is formed by a continuous wall.

11. A plant protection treatment assembly comprising a spraying device according to any one of claims 1 to 10, characterized in that the gas production and / or storage device comprises a bypass to the reservoir for enriching the liquid with gas contained in the tank, so that the liquid contains a proportion of dissolved gas before spraying.

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