ES2783073A1 - DEVICE AND PROCEDURE TO REDUCE THE DROP SIZE IN LIQUID SPRAYING - Google Patents

Abstract

Device and procedure to reduce the droplet size in liquid sprays, which is based on a head that is fixed to a spray nozzle, in which the aqueous fluid circulates in a turbulent regime, which is located at the end of a pipeline in which A fluid under pressure circulates, said head comprising at least one set of magnets of ferromagnetic material located on its inner or outer perimeter which affect the aqueous fluid by generating a magnetic field with lines of force preferably perpendicular to the direction of circulation of the fluid; and where the procedure reduces the size of the droplets up to 23.15% compared to an unmagnetized fluid.

Description

DESCRIPTION

DEVICE AND PROCEDURE TO REDUCE THE DROP SIZE BY

LIQUID SPRAYS

Field of the invention

The present invention relates to a device comprising permanent magnets that generate magnetic fields in aqueous fluids used in spraying, and the procedure required for the dispersion or reduction of the size of drops.

Magnetic fields reduce the average spray droplet size and modify the distribution spectrum of the sprayed droplets by increasing the number of smaller droplets and decreasing the larger ones. By means of the present invention a solution is developed with which the objective of spraying is achieved, but consuming less liquid and without increasing energy consumption.

The present invention falls within the technical sector of physical treatment processes for aqueous liquids, more specifically in relation to magnetic methods that modify the properties of aqueous liquids in spraying equipment.

State of the art

It is known that aqueous liquids, such as distilled water, tap water and aqueous solutions with solutes or with other liquids, that flow through a circuit or that temporarily remain immobile in a tank, are affected by applying magnetic fields to them, whose lines of force through the liquid, which is temporarily magnetized, modifying some of its properties.

After this magnetization process some properties of the water change giving rise to anomalies in comparison with the same unmagnetized liquid. Various effects of magnetic fields on water molecules that flow, or that are still, have been experimentally investigated and it has been pointed out that these magnetic fields can modify: absorbance, refractive index, thermal conductivity, viscosity, surface tension, evaporation, solidification and boiling point, pH and solubility of water, in addition changes in the grouping structure of their molecular chains, shape and size of crystallization. This magnetization process depends not only on the intensity of the magnetic field, but also on the duration of the aqueous fluid's exposure to the magnetic field.

The most common application of magnetic fields to water and aqueous fluids has been to prevent the formation and removal of scale in pipes and boilers; reduction of the corrosion index; increasing the efficiency of wastewater treatment; increasing the development and yield of agricultural crops; or the separation of ions in desalination processes, as for example disclosed in the inventions ES1066215U, ES1067217U or WO2010023335. In these cases, the objective has been to magnetize the running water that circulates through standardized pipes with a nominal diameter> 16 mm, in supply facilities with meters for domestic, industrial or agricultural use, using one or more permanent magnets that generate magnetic fields. Other devices are known in which the magnetic treatment is carried out in such a way that the water is circulated through a serpentine pipe or with a twisted circuit design, and even the main pipe is subdivided into several pipes of smaller nominal diameter. By way of example, these pipe designs are disclosed in documents WO2012 / 146217, WO03 / 000596, WO95 / 14885, ES-2014912, ES-2085824, ES-8201107, ES2043186 and ES2085824. Taking into account the diameters of the conduits and pipes of the aforementioned devices, as well as the admissible speeds at any point in them (0.5-2.0 m / s so that there is no deposition of solids or erosion of the conduction), and the density (1,000 kg / m3) and viscosity (10-3 kg / ms) of the fluid it transports (tap water), the flow of water circulating in them is carried out in a turbulent regime preferably comprised between 16,000 <R <25,000, with R being the Reynolds number, and occasionally decreasing turbulence until reaching a transition regime (2,000 <R <4,000) or even a laminar regime (R <2,000).

In other cases, a plurality of magnets attached to the inside or outside of a water storage tank are used. Alternatively, it is also known to use electric currents flowing through conductor coils wrapped around the circulating water pipe or the water storage tank, to generate the magnetic field by self-induction.

In all the above cases, the place where the source that generates the permanent magnetic field is placed is in the middle of the conduction and never in a singular area (for example, pipe end, elbow, reduction cone, union sleeve, branch tee, valve).

In another vein, it is also known in this technical field that the application of certain aqueous fluids by spraying, for example, phytosanitary products, paints, cleaning products and humidifiers, is a highly precision technique, which requires using sufficient working pressure. to generate a certain turbulent regime of liquid circulation inside the nozzles, and specify the desired result with the spraying.

In this sense, the spraying devices use volumes of liquid in relation to the surface to be treated, these being greatly influenced by the size of the sprayed droplet. The droplet size is defined by its diameter (0) and depends on the characteristic constant of the sprayer nozzle (K), on the surface of the calibrated outlet orifice of the nozzle (S), on the universal gravitational constant (g ) and the working pressure of the sprayer (P),

K-S

by the expression: 0 The droplet size, fixed by the droplet volume (V), is 4 - & p .

. Para un mismo determined by its diameter (D), according to the expression: V =

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The volume of liquid, taking both expressions into account, as the size of the sprayed drop decreases, the number of sprayed drops increases more than proportionally and, consequently, the surface area wetted by the spray apparatus increases. In other words, for a given volume of liquid, the level of coverage (treated surface covered by sprayed droplets in relation to the total surface to be sprayed) increases with decreasing droplet size. Therefore, in order to maximize the level of coverage of a surface to be sprayed and minimize the volume of aqueous liquid used, it is important to produce a spectrum of drops where the smallest possible size drops predominate, until reaching a limit that avoids drift and evaporation. of those powdered drops. In practice, for a given spray nozzle, this objective is necessarily achieved by increasing the usual working pressure of the sprayer, that is to say increasing energy consumption in turn.

Taking into account the existing antecedents in this field of the art, there is a technical problem consisting of modifying the properties of aqueous liquids with which the volume of liquid to be sprayed is reduced, without increasing the working pressure of the sprayer, and that in turn once the desired objective is achieved with the spraying. The present invention achieves, in the face of known solutions and existing problems, to increase the range of drops of smaller size without increasing the range of larger drops, thanks to the influence of the magnetic field generated by permanent magnets, without increasing the working pressure of the sprayer, nor its energy consumption.

Specifically, no document is known that discloses a solution in which the droplet size is reduced in sprays of aqueous liquids by the application of magnetic fields. In fact, in the previously indicated magnetic devices with permanent magnets, it is impossible to achieve the effects obtained with our invention, such as reducing the droplet size in the sprayed droplet size spectrum, for several reasons:

(i) In the present invention the magnet generating the magnetic field is fixed to a spray nozzle located at the end of a conduit of aqueous liquid, against the arrangement of the magnetic field in the middle of the conduit as described in known devices. In the event that in these devices the magnet had been placed at the end of the pipe with a diameter> 16 mm, even reducing the outlet diameter to one equal to that of a spray nozzle, at the outlet of the pipe there would be no spraying, but a jet of water, therefore, the desired function would not have been successful.

(ii) The magnetic field used in the present invention is applied to an aqueous liquid that circulates inside a spray nozzle in a turbulent flow regime (R> 50,000), much higher than the turbulent flow regime of the other devices (16,000 <R <25,000) in which the flow regime can occasionally become transitional and even laminar. This turbulent regime with R> 50,000 is a necessary first step to ensure that magnetization can reduce the size of the sprayed droplets. It has been shown that a very high turbulent regime breaks the natural grouping of the water molecules in the aqueous liquid and allows the magnetic field to induce a new molecular rearrangement resulting in a more fluid liquid as it passes through the calibrated exit orifice of the nozzle of the sprayer. In our invention, this first molecular regrouping is added a second regrouping produced by the magnetic field on the fluid once the calibrated outlet orifice of the sprayer has been passed. This second rearrangement occurs when the fluid is out of the pressure conduction and during the previous state and the beginning of its separation into drops, and is the one that finally allows a spectrum of sprayed drops of smaller size to be achieved.

(iii) The duration in time of the changes produced in the aqueous liquid after its magnetization is proportional to the intensity and the time of exposure to the magnetic field used. In the present invention, even when using a low magnetic field intensity and very short exposure to said field, the possible demagnetization of the liquid watery would never occur before being sprayed. In this sense, in the present invention the liquid is magnetized when it circulates inside the spray nozzle and also during the initial drop formation process that occurs after passing the calibrated outlet orifice of the spray nozzle. In the other known magnetic devices, the aqueous fluid once magnetized (generally with low field strengths and reduced exposure time), continues to circulate through the domestic, industrial or agricultural conduction or pipeline and progressively loses its magnetic properties.

(iv) The effect of the magnetic field decreases with distance to the aqueous fluid. In our invention, this distance is very small, normally <2.5 mm (thickness of the nozzle material), so the effect of the magnetic field is complete in the aqueous fluid, also achieving great uniformity in the magnetic treatment of the fluid. . In other inventions, the effect of the magnetic field is drastically reduced with the increase in the diameter of the conduction (generally> 16 mm), this effect being much less in the center of the conduction compared to the periphery, so the magnetization is not uniform throughout the fluid, being able to not affect part of the fluid when using conduction diameters greater than 20 mm.

Taking these aspects into account, it can be determined that the present invention solves the problem of reducing the droplet size in sprays of aqueous liquids by applying magnetic fields in conduits and pipes with a diameter much smaller than the commercial diameter (> 16 mm) and in a very turbulent flow regime (R> 50,000), something that is neither disclosed nor suggested in the documents known in this technical field.

Description of the invention

According to an experimental embodiment of the present invention, the magnetic process is applied to tap water flowing in a pressurized circuit of a sprayer working 1.7 atm (atmosphere) of pressure in a first embodiment. In this embodiment, the magnetic field has an intensity of 5.1 mT (milli Tesla), has lines of force perpendicular to the direction of the flow of running water that circulates inside the nozzle of the sprayer, and is generated by two magnets of permanent ferrite positioned coaxially and opposite on the outside of the spray nozzle (ceramic material; 1.0 mm calibrated outlet diameter; full cone spray pattern) which is attached to the end of the spray lance, such as indicated in Fig. 1.

According to other experimental embodiments of the invention, working pressures of between 2.0 and 7.4 atm have been used, and magnetic fields with intensities between 8.7 and 11.0 mT. To carry out these laboratory tests, any existing spray nozzle on the market with a different diameter of calibrated outlet or other type of spray pattern could have been chosen. In the same way, this device has been used, but without placing ferrite magnets, to spray tap water without magnetizing.

In general, to compare the sprayed droplets from both treatments, digital photographs of the sprayed surfaces are first taken, located 1 m from the spray nozzle, and then each image is digitally analyzed with the help of the ImageJ 1.51K® program, developed by National Institutes of Health (US), and by the Gotas v2.2® program, available by EMBRAPA (Ministério da Agricultura, Pecuária e Abastecimento do Brasil). With these programs, the size (mm2), perimeter (mm) and circularity are obtained (values 0-1; a perfect circle has a circularity of 1 while an irregular or very 'pointed' object has a circularity value closer to 0 ) of each sprayed drop. The statistical comparison between magnetized and non-magnetized droplets is performed with the statistical program IBM SPSS Statistics v22.0. With this program you obtain: mean, standard error, confidence interval (95%), median, maximum and minimum values and standard deviation (Table 1), and histogram of relative frequencies of the distribution of the drops tabulating the data in different ranges by size (Fig. 3).

Table 1.- Summary descriptive statistics.

The average results obtained with the different magnetic field intensities and working pressures indicate that the magnetic treatment reduces the average size of the sprayed droplets between 4.12-23.15%, the average perimeter between 3.21-10.46% and the average circularity between 0.98-3.02%, compared to spraying with non-magnetized water. The smallest and largest values in each interval have been obtained using the lowest magnetic field intensity (5.1 mT) and working pressure (1.7 atm) of the sprayer, and with the highest magnetic field intensity (11 , 0 mT) and working pressure (7.4 atm) of the sprayer, respectively of the various experimental realizations carried out.

These preferred examples can essentially be carried out in other embodiments. For example, they may differ in the type, number and intensity of the permanent magnets that generate the magnetic field, their location (outside or inside the spray nozzle), or even make nozzles with magnets included in their structure (Fig. 2). This example is also applicable to spray nozzles of different types of material (ceramic, polymer, brass, stainless steel, hardened stainless steel, etc.), with other droplet dispersion patterns (flat or slit, turbulent or cone jet, of impact or mirror, compact jet or multi-outlet, etc.), or with higher working pressures (7.5-20 atm).

This procedure makes it possible to reduce the size spectrum of the sprayed droplets and achieves, with the same volume of aqueous liquid and without increasing the working pressure, to increase the sprayed surface without increasing the energy requirements of the sprayer. The industrial applications of this procedure are varied depending on the objective and the surface to be sprayed. For example, it can be used to improve-optimize sprays of phytosanitary and herbicides in agriculture, inhalers in medical applications, diffusers for environmental humidity control (eg nebulizers), etc.

Taking into account the above aspects, it can be defined that the procedure for reducing the droplet size in liquid sprays comprises the following steps:

i) a circulation of the aqueous fluid through a conduit or through a lance at a pressure comprised between 1-20 atm;

ii) passage of the aqueous fluid through a spray nozzle located at the end of the conduit or lance, which forces the fluid to circulate in a turbulent regime of R> 50,000 and which has a head with at least 2 magnets as defined in the previous examples;

iii) a generation of magnetic fields perpendicular to the flow direction of the aqueous liquid with a magnetic field intensity comprised between 1-25 mT, preferably between 5.1 and 11 mT;

iv) a first magnetization of the aqueous fluid when it circulates inside the spray nozzle before passing through the calibrated outlet orifice thereof;

v) a second magnetization when this fluid has passed through the calibrated outlet orifice of the spray nozzle and begins to divide into drops;

vi) a decrease in the mean droplet size of between 4.12 and 23.15%, compared to non-magnetized water; Also achieving a reduction of the average perimeter between 3.21-10.46% and the average circularity between 0.98-3.02%, compared to spraying with non-magnetized water; Y

vii) fluid projection according to the spray head outlet pattern.

It should be noted that, throughout the description and claims, the term "comprises" and its variants are not intended to exclude other technical characteristics or additional elements.

To conclude, in order to complete the description and help a better understanding of the characteristics of the invention, a set of figures and drawings is presented in which the following is represented by way of illustration and not limitation:

Figure 1.- Representation of a section of the device, where the conduction (1) or lance, the magnets (2) and the nozzle (3) of the sprayer with liquid flowing inside, calibrated outlet orifice (4) and where the lines of forces of the magnetic fields (5) between magnets are also observed.

Figure 2.- Representation of a section of a device where the magnets that are located inside the nozzle are observed, forming part of its structure.

Figure 3.- Representation of the histograms of relative frequencies of the distribution of sprayed drops.

Figure 4.- Representative diagram of the different stages of the procedure to reduce the droplet size in liquid sprays.

Detailed description of the figures of the invention.

In Fig. 1 you can see the device to decrease the droplet size in spraying of liquids object of the present invention, which has the particularity that it is a head that is fixed to a spray nozzle (3) that is located at the end of a conduit (1) or lance, said head comprising at least one set magnets (2) made of ferromagnetic material located on its outer perimeter; and where it has at least one outlet hole (4) for the spray nozzle, preferably being an orifice that is calibrated and with an outlet with a diameter much less than 16 mm. In this sense, the spray nozzle (3) can be made of a material selected from among plastic polymers, brass, stainless steel, hardened stainless steel and ceramic material; while the magnets (2) are made of a material selected from ferrite, neodymium, samarium and alnico. Going into more detail, said magnets (2) can be of a geometry selected from among block, button, disk, ring, rod, laminar, tape and spatial geometry.

The objective sought in the invention, and which is also observed in Fig. 2, which is another embodiment of the invention, is that the magnets generate magnetic fields with an intensity between 1-25 mT, mainly perpendicular to the direction of the flow. of the aqueous liquid, since any other angle less than 90 ° reduces the efficiency.

In any case, as can be seen in Fig. 1, an embodiment of the invention is characterized in that the head is externally fixed to the spray nozzle (3); while in Fig. 2, the head is internally fixed on the spray nozzle (3).

It should also be noted that the arrangement of the set of magnets (2) is coaxial with respect to the spray nozzle (3) (Fig.1 and Fig.2); however, in another embodiment of the invention, the magnets (2) can be located parallel to the spray nozzle.

Fig. 3 shows the histograms of the relative frequencies of the spray droplet distribution, taking into account the data from the summary of Table 1. In this sense, the percentage distribution of the magnetized droplet size (F.3A) in comparison with the non-magnetized (F.3B). It is observed that in the range of smaller drops (0-0.1 mm2) there is a higher proportion of magnetized drops (78.6%) than non-magnetized drops (73.4%). It is also observed that the largest magnetized drops are in the range 3.2-3.3 mm2, while the non-magnetized drops are in the range 5.4-5.6 mm2. This shows that the magnetic field increases the number of smaller droplets and decreases the number of larger droplets, compared to unmagnetized water. The graphs represent the size (T) of the drops in mm2 with respect to the percentage (%).

On the other hand, the percentage distribution of the perimeter of the magnetized drop (F.3C) compared to the non-magnetized one (F.3D) can also be observed. It is observed that the range of drops with the smallest perimeter (0-0.285 mm) has a higher proportion of magnetized drops (32.0%) than non-magnetized (31.6%). The graphs represent the perimeter (P) of the drops in mm2 with respect to the percentage (%).

Finally, the percentage distribution of the circularity of the magnetized drop (F.3E) in comparison with the non-magnetized one (F.3F) can be observed. It is observed that in the interval of greater circularity (0.983-1) there is a greater proportion of non-magnetized drops (68.2%) than of magnetized drops (66.2%). Therefore, the results obtained indicate that this procedure reduces the mean size of the sprayed droplets up to 23.15%, the mean perimeter up to 10.46% and the mean circularity up to 3.02%, compared to spraying. with unmagnetized water. The graphs represent the circularity (C) of the drops with respect to the percentage (%).

Fig. 4 shows a diagram with the different stages of the droplet dispersion or reduction procedure, which are:

i) a circulation of the aqueous fluid through a conduit at a pressure comprised between 1 -20 atm, where the diameter of the conduit is less than the commercial diameter (<16mm);

ii) passage of the aqueous fluid through a spray nozzle that achieves a turbulent flow regime (R> 50,000), and that has a head with a set of magnets;

iii) a generation of magnetic fields perpendicular to the flow direction of the aqueous liquid with a magnetic field intensity comprised between 1 -25 mT;

iv) a first magnetization of the aqueous fluid when it circulates inside the spray nozzle before passing through the calibrated outlet orifice thereof.

v) a second magnetization when this fluid passes through the calibrated outlet orifice of the spray nozzle and begins to divide into drops.

vi) decrease in the average droplet size and a dispersion of droplets, where the decrease in size is up to 23.15% compared to the unmagnetized fluid;

vii) fluid projection according to the spray head outlet pattern.

Claims (13)

1. - Procedure to reduce the droplet size in liquid sprays, which comprises the following steps: i) a circulation of the aqueous fluid through a conduit at a pressure comprised between 1-20 atm; ii) passage of the aqueous fluid through a spray nozzle, wherein said fluid circulates at a turbulent flow regime with R ( Reynolds number) > 50,000, said nozzle comprising a head with a set of magnets; iii) generation of magnetic fields perpendicular to the flow direction of the aqueous liquid with a magnetic field intensity comprised between 1-25 mT; iv) a first magnetization of the aqueous fluid when it circulates inside the spray nozzle before passing through the calibrated outlet orifice of the spray head; v) a second magnetization when this fluid passes through the outlet orifice of the spray nozzle, where the fluid begins to divide into drops; vi) decrease in droplet size and dispersion of droplets; Y vii) projection of the fluid according to the exit pattern of the head of the spray nozzle. 2. Procedure for reducing the droplet size in liquid sprays, according to claim 1, wherein the diameter of the conduit is less than 16 mm. 3. Method for reducing the droplet size in liquid sprays, according to claim 1, wherein the decrease in droplet size is up to 23.15% compared to an unmagnetized fluid. 4. Device for reducing the droplet size in liquid sprays according to the method of any of the preceding claims, characterized in that it comprises a head that is fixed to a spray nozzle (3) that is located at the end of a pipe (1), said head comprising at least one set of magnets (2) made of ferromagnetic material located perimeter in the contour of the nozzle (3), and at least one outlet hole (4). 5. Device for reducing the droplet size in liquid sprays, according to claim 4, wherein the spray nozzle (3) is made of a material selected from among plastic polymers, brass, stainless steel, hardened stainless steel and ceramic material. 6. Device for reducing the droplet size in liquid sprays, according to claim 4, wherein the magnets (2) are made of a material selected from among ferrite, neodymium, samarium and alnico. Device for reducing the drop size in liquid sprays, according to claim 4, where the magnets (2) are of a geometry selected from among block, button, disk, ring, rod, laminar, tape and spatial geometry. 8. Device for reducing the droplet size in liquid sprays, according to claim 4, wherein the magnets (2) generate magnetic fields (5) perpendicular to the flow direction of the aqueous liquid. Device for reducing the droplet size in liquid sprays, according to claim 4, wherein the head is externally fixed to the spray nozzle (3). 10. Device for reducing the droplet size in liquid sprays, according to claim 4, wherein the head is internally fixed on the spray nozzle (3). 11. Device for reducing the droplet size in liquid sprays, according to claim 4, wherein the set of magnets (2) is located coaxially with respect to the spraying nozzle (3). 12. Device for reducing the droplet size in liquid sprays, according to claim 4, where the set of magnets (2) is located parallel to the spray nozzle (3). Device for reducing the droplet size in liquid sprays, according to claim 4, wherein the calibrated outlet orifice (4) of the spray nozzle is calibrated and has a diameter of less than 16 mm.