WO2010052388A1

WO2010052388A1 - Method for forming an emulsion from liquids mutually immiscible and application for the liquid supply of a nebulisation device

Info

Publication number: WO2010052388A1
Application number: PCT/FR2009/001274
Authority: WO
Inventors: Jean-Claude Millet; Florence Wagner; Laurent Michel Foucher
Original assignee: Osmooze
Priority date: 2008-11-05
Filing date: 2009-11-04
Publication date: 2010-05-14
Also published as: FR2937884A1

Abstract

A method for mixing liquids (5a, 5b) that are mutually immiscible, said method including steps of contacting the liquids together and agitating said liquids in order to obtain a substantially homogenous and temporarily stable mixture, the liquids being agitated by submerging a bevelled nozzle (32b, 43) of a capillary tube (30b, 40) in the vicinity of a contact area between the liquids, and by vibrating the capillary tube. The invention can particularly be used for the nebulisation of liquids in the air, also using a vibrating capillary tube.

Description

PROCESS FOR FORMING EMULSION FROM LIQUIDS

NOT MISCIBLE IN THEM AND APPLICATION TO FOOD IN

LIQUID OF A NEBULIZATION DEVICE

The present invention relates to the formation of emulsions from immiscible liquids therebetween, or mixtures of liquids with pigments. The present invention applies more particularly to the liquid supply of a liquid nebulizing apparatus projecting fine droplets into the air, in particular to broadcast sanitizing, deodorant, disinfectant, perfume or pest control active products. .

The present invention applies to all types of nebulizing heads, such as those described in patent EP 0 714 709 comprising ejection channels subjected to vibration, or using piezoelectricity or electrostatic or Venturi effect. The targeted nebulization can be applied to the treatment of ambient air such as the diffusion of perfume, or the sanitation of the hands and, more generally, the skin. Targeted nebulization can also be applied to the projection of paint pigments, varnishes or lubricants.

To effect nebulization of an active product, it is desirable to mix the active product with a solvent. In fact, the nebulization makes it possible to diffuse into the air a multitude of droplets of a mixture of solvent and of active product. These droplets that are carried by drafts behave like diffusers that gradually release their active product.

However, certain active nebulizing products such as perfumes and essential oils are generally oily products, which are therefore not miscible with water. To diffuse these active products in the air, it is therefore necessary to use an organic solvent, such as an alcohol, or a solution of water and surfactants. However, these solvents and surfactants can increase the sensitivity of nebulization to ambient conditions, including temperature, pressure and humidity, as well as the nature of the active product to be sprayed. Indeed, it can be observed that with certain compositions of active product and solvent or surfactant, the amount of liquid nebulized with each nebulization can vary from one significantly depending on the ambient conditions. Moreover, the marketing of many products used as solvents or surfactants is subject to specific regulations, often binding, in relation to their harmfulness to the skin or the respiratory tract. Some of these products also have a high cost.

It is therefore desirable to use a solvent that is chemically and physically neutral, has no harmful effects on the skin and respiratory tract, meets environmental standards and regulations, is inexpensive, and can be used with all active products likely to be nebulized.

For this purpose, the present invention aims to nebulise an active product in the air or to the skin using a carrier liquid that is not necessarily miscible or soluble with all the compositions to be diffused in the air, and in particular the hydrophobic compositions like perfumes or essential oils, or compositions in powder form such as pigments.

In one embodiment, there is provided a method of mixing liquids, comprising steps of contacting liquids therebetween, in a tank and agitating the liquids to obtain a substantially homogeneous mixture. According to one embodiment, the method comprises steps of circulating at least one of the liquids in a capillary tube comprising a beveled end immersed in the vicinity of a contact zone between the liquids, and of vibrating the tube by means of a piezoelectric vibrating member for stirring the liquids. According to one embodiment, the contacting of the liquids is carried out substantially simultaneously with the stirring of the liquids, by introducing a first of the liquids into a second of the liquids by the capillary tube driven in vibration.

According to one embodiment, the contacting of the liquids is carried out by introducing the liquids into a reservoir, and the stirring of the liquids is carried out after the introduction of the liquids into the reservoir.

According to one embodiment, the tube is disposed substantially vertically or substantially horizontally.

According to one embodiment, the liquids are immiscible with each other, one of the two liquids possibly comprising water. In one embodiment, there is also provided a method of nebulizing in air a first liquid and a second liquid comprising an active product. According to one embodiment, the nebulization process comprises steps of mixing the two liquids according to the method according to one of claims 1 to 5, to obtain a substantially homogeneous mixture, and nebulization of the mixture.

According to one embodiment, the mixing of the liquids is carried out simultaneously with the nebulization of the mixture.

According to one embodiment, the mixing of the liquids is carried out in an intermediate reservoir that can contain at most a quantity of nebulized mixture in one or a few nebulization cycles.

According to one embodiment, the nebulization is performed by another capillary tube which may be identical to the capillary tube provided for stirring the liquids. According to one embodiment, the nebulization is carried out by a beveled end of the capillary tube, and the mixing of the liquids is carried out by another bevelled end of the capillary tube.

In one embodiment, there is also provided a liquid mixing device, comprising a reservoir in which liquids are brought into contact. According to one embodiment, the device comprises a capillary tube comprising a beveled end arranged to be immersed in the vicinity of a contact zone between the liquids, and a piezoelectric vibrating member coupled to the tube for vibrating the tube in order to agitate. liquids in the tank. According to one embodiment, the capillary tube is arranged to introduce one of the liquids into the reservoir.

According to one embodiment, the device comprises a control circuit configured to trigger the introduction of one of the liquids into the reservoir by the capillary tube after vibrating the capillary tube. According to one embodiment, the tube is disposed substantially vertically or substantially horizontally.

According to one embodiment, the capillary tube comprises an upstream opening of liquid inlet which is closed by a part which deviates from the upstream opening under the effect of vibrations, when the capillary tube is vibrated to introduce the liquid in the tank. In one embodiment, there is also provided a device for nebuiization in the air of a first liquid and a second liquid containing an active product. According to one embodiment, the nebulization device comprises: a mixing device according to one of claims 11 to 15, to obtain a substantially homogeneous and unstable mixture from the two liquids in an intermediate reservoir, and a nebulization head for nebulize the mixture.

According to one embodiment, the nebulization head comprises a capillary nebulization tube, one end of which forms a nebulization nozzle, a vibrating member for driving the vibrating nebulization head, so that it ejects droplets of liquid into the air. in a nebulization jet, and an excitation circuit for applying to the vibrating member an excitation signal during each nebulization cycle.

According to one embodiment, the capillary nebulization tube and the mixing capillary tube are identical and are vibrated by identical vibrating members.

According to one embodiment, the capillary nebulization tube comprises a beveled end arranged so as to stir the liquids in the intermediate reservoir to form a mixture, and another bevelled end to nebulize the mixture in the air, when it is set. in vibration.

According to one embodiment, the intermediate reservoir has a volume that can contain at most the volume of nebulized mixture in one or a few cycles of nebulization. According to one embodiment, the intermediate reservoir is connected by a siphon to a closed main reservoir, so that the level of liquid in the reservoir is substantially constant.

According to one embodiment, the nebulization device comprises a filling control device for controlling the proportions of liquids in the intermediate reservoir.

Exemplary embodiments of the invention will be described in the following, without limitation in connection with the accompanying figures in which: - Figure 1 shows schematically a nebulization device according to one embodiment, FIG. 2 is a timing diagram illustrating the operation of the nebulization device represented in FIG. 1;

FIG. 3 diagrammatically represents a filling control device, according to one embodiment, FIG. 4 schematically represents a nebulization device according to another embodiment,

FIG. 5 schematically represents a nebulization device according to another embodiment,

FIG. 6 schematically represents a nebulization device according to another embodiment,

FIG. 7 is a timing diagram illustrating the operation of the nebulization device of FIG. 6,

- Figure 8 schematically shows a nebulizing device according to another embodiment. FIG. 1 represents a nebulization device NBCT1 according to one embodiment. The NBCT1 nebulizing device comprises two main tanks 1a, 1b containing liquids 5a, 5b to be sprayed, and a nebulization circuit fed by the tanks 1a, 1b. The nebulizing circuit comprises a nebulizing head 30, an intermediate reservoir 10 supplying the nebulizing head, channels 2a, 2b connecting the reservoir 10 to the tanks 1a, 1b, and filling control devices 12a, 12b to control the quantities of the liquids 5a, 5b introduced into the tank 10 from the tanks 1a, 1b.

The nebulizing head 30 is for example of the vibrating capillary tube type. Thus the nebulizing head comprises a capillary tube 31 which can be horizontal, and a nozzle 32 for ejecting the liquid nebulized in the air. The nebulizing head generally has the shape of a hollow needle forming the capillary tube 31. The needle has an inner diameter of the order of 0.4 to 1 mm, and a length of a few centimeters, typically between 2 and 4 cm. The distal end of the tube 31 is beveled and forms the ejection nozzle 32. The proximal end of the nebulizing head

30 opens directly into a lower region of the tank 10. The tube

31 is mechanically coupled to a vibrating means, for example a piezoelectric transducer TPE1 with resonator. The transducer TPE1 is excited by an alternating signal Sv1 supplied by an excitation circuit EXCT. The EXCT circuit is controlled by a CNCT control circuit which defines the duration of nebulization cycles during which the nozzle 32 emits nebulized liquid, and the duration of periods of rest between the nebulization cycles. The CNCT circuit also controls the filling control devices 12a, 12b to adjust the quantities of the liquids 5a, 5b introduced into the intermediate tank 10 from the tanks 1a, 1b. For this purpose, the CNCT circuit may be connected to a liquid level measuring device 14 in the tank 10. The tanks 1a, 1b and 10 are subjected to atmospheric pressure.

The filling control devices 12a, 12b may be solenoid valves, or valves for example of the piezoelectric type, or even micropumps, and be controlled by control signals supplied by the control circuit CNCT.

When the excitation signal Sv1 is applied to the transducer TPE1, the tube 31 resonates and droplets of the liquid coming from the intermediate tank 10 are ejected into the air, forming a kind of mist of droplets or "jet of nebulization" . During nebulization, the nebulizing head 30 is supplied with liquid by capillarity and by gravity (effect of a hydrostatic overpressure). Air circulation means such as a fan (not shown) may be provided to increase the range of the nebulizer jet. The frequency of the vibrations transmitted to the tube 31 during a nebulization cycle may be between 150 and 300 kHz, for example around 200 kHz.

At rest, when the nebulizing head 30 is not driven in vibration, the liquid in the tank 10 is retained in the misting head by capillarity, and the hydrostatic pressure is compensated by the appearance of a convex meniscus of liquid at the end 32 of the nebulizing head, due to the surface tension forces acting on the liquid. Beyond a critical threshold of overpressure, the meniscus breaks and the liquid flows through the nozzle 32. According to one embodiment, the nebulization device NBCT1 comprises downstream of the filling control device 12b a capillary tube mixture 30b, similar to the capillary nebulization tube 30 for ensuring the mixing of the two liquids 5a, 5b, even if they are not miscible with each other. The tube 30b includes a distal end 32b located in the reservoir 10, which is tapered and forms a liquid ejection nozzle 5b in the reservoir 10. Thus, the liquid 5b when It comes into contact with the other liquid in the reservoir 10 and remains subjected to vibrations from the end of the tube to a certain distance from it. The tapered end thus acts on the liquids to be mixed, producing a stirring and beating effect. The upstream end of the tube 30b is connected to a lower region of the tank 1b. The tube 30b is mechanically coupled to a vibrating means, for example a piezoelectric transducer TPE2 with a resonator. The transducer TPE2 is excited by an alternating signal Sv2 supplied by the excitation circuit EXCT or another circuit. The frequency of the vibrations transmitted to the tube 30b for mixing the liquids in the reservoir 10 may be between 100 and 300 kHz, for example around 200 kHz.

The intermediate reservoir 10 has a volume such that it can at most contain the amount of liquid nebulized in one or a few cycles of nebulization. The reservoir 10 can be sealed in its upper part, for example by means of a flexible membrane 11 through which the mixing tube 30b passes in a sealed manner. The flexibility of the membrane 11 allows in particular to limit the vibrational energy loss of the tube 30b and to maintain substantially at atmospheric pressure the liquid 5b in the tank 1b. In addition, the contact area of the tube 30b with the membrane 11 may be arranged to coincide with a vibration node of the tube 30b so as to further reduce the vibrational energy loss. The capillary tube 30b has an internal diameter of between 0.4 and 1 mm, for example of the order of 1 mm or less than this value, and a length of a few centimeters. The tube 30b for example has a length of about 27 mm and a bevel of about 2 mm long, forming a tip at the end of the tube having an angle that can be between 10 and 45 °, for example of 20 °.

The reservoir 1 may be designed to contain a solvent or a mixture of solvents, or more generally, a chemically and physically neutral liquid, which has no harmful effect on the skin and the respiratory tract. The tank 1b, for example of smaller dimensions than the tank 1a, can in turn be provided to contain a liquid comprising one or more concentrated active products such as a sanitizer, deodorant, disinfectant, fragrance or anti-aging. harmful. By for example, the liquid 5a in the tank 1a comprises water and the liquid 5b in the tank 1b comprises an oily active product, such as a perfume or an essential oil.

The capillary tubes 30b and 31 may be identical, as well as the piezoelectric transducers TPE1, TPE2, in order to simplify the control circuits and to minimize costs.

FIG. 2 represents a sequence P1 of operation of the nebulization device NBCT1. In an initial state, the fill control devices 12a and 12b are in the closed state, and the excitation signals Sv1 and Sv2 are in an inactive state. As a result, no liquid flows into the reservoir 10 and the tubes 31, 31b are at rest. At a time t0, the CNCT circuit triggers a filling cycle of the tank 10 by controlling the opening of the device 12a to fill the tank 10 of the liquid 5a contained in the tank 1a. When a certain amount of liquid 5a has been introduced into the tank 10 at time t1, the CNCT circuit controls the closure of the device 12a. The nozzle 32b of the tube 30b is then immersed in the liquid 5a in the tank 10. At the instant t2, a few milliseconds after the instant t1, the CNCT circuit controls the excitation circuit EXCT to activate the signal Sv2, and thus to vibrate the mixing tube 30b. At time t3, a few tens of milliseconds after time t2, the CNCT circuit controls the opening of device 12b to supply liquid 5b to tube 30b while in vibration. As a result, at the distal opening 32b of the tube 30b, the liquid 5b is stirred violently in contact with the liquid 1a and mixes with the latter. If the two liquids 5a, 5b are immiscible with each other, the formation of an emulsion which extends rapidly by edge effect can be observed locally in the vicinity of the opening 32b. At the beginning of the contacting of the liquids, an emulsion is formed locally near the beveled end 32b of the tube 30b. As the liquid 5b is introduced into the liquid 5a through the tube, the liquid 5b mixes with the emulsion formed locally. As a result, the emulsion propagates in the reservoir around the end 32b to finally reach a liquid concentration 5b in the substantially uniform liquid 5a when the liquid 5b ceases to flow into the reservoir 10. If the reservoir 10 has reduced dimensions, typically 7 to 10 mm 2 of surface (for example 3 mm in diameter) and 6 to 10 mm in height, the emulsion is rapidly propagated to all the liquid contained in the reservoir 10 The emulsion thus obtained is substantially homogeneous and unstable over time, the two immiscible liquids between them tending to gradually separate. At time t4, the CNCT circuit controls the closure of the device 12b to stop the flow of the liquid 5b in the reservoir 10. The liquid in the reservoir 10 is then in the form of a substantially homogeneous emulsion. The time between instants t3 and t4 is determined according to the known flow rate of the tube 30b and the desired concentration of the liquid 5b in the liquid 5a. At time t5, a few tens of milliseconds after time t4, the CNCT circuit controls the excitation circuit EXCT to disable the signal Sv2. At time t6, the CNCT circuit triggers a nebulization cycle of the liquid in the tank 10 by controlling the excitation circuit EXCT to activate the signal Sv1. At a time t7, the CNCT circuit terminates the nebulization cycle by deactivating the signal Sv1. At time t7, all the liquid in the tank 10 may have been nebulized. After a certain period of rest, the CNCT circuit performs a new filling cycle of the tank 10 as at time t0.

If the stability of the mixture obtained allows, given the duration of a nebulization cycle and a rest cycle between two nebulization cycles, the reservoir 10 may contain the volume of liquid required for several nebulization cycles. In this case, several nebulization cycles can be executed (between times t6, t7 and t0 of a next nebulization cycle) before filling the reservoir 10 again (from time tO).

The liquids 5a, 5b in the tanks 1a, 1b can be interchanged. Thus, in the example of oily products such as perfumes and essential oils that are to be mixed with water, the tank 1b may contain the oily product or water.

In the operating sequence of FIG. 2, the excitation circuit activates only one of the signals Sv1, Sv2 at a time to vibrate either the mixing tube 30b or the nebulizing tube 30. However, the excitation signals Sv1 and Sv2 may be different, each tube may have a clean excitation mode adapted to the function of the tube. Furthermore, it can be expected to maintain the tube 31 has vibration during nebulization, the device 12b being in the closed state.

In the embodiment shown in FIG. 1, the mixing tube 30b is disposed substantially vertically above the intermediate reservoir 10.

Fig. 3 shows an embodiment of the filling control device 12b. The upstream opening 33b opposite the ejection nozzle 32b of the tube 30b, disposed substantially vertically, penetrates into the tank 1b. The filling control device 12b comprises a ball

51 disposed on the opening 33b of the tube 30b, and guide means 55 of the ball, arranged around the opening 33b, to limit the lateral movements of the ball 51 from a position where the ball closes the ball opening 33b.

When the tube 30b is at rest, its upstream opening 33b is closed by the ball 51 which therefore prevents the liquid 5b from flowing into the tube 30b. When the tube 30b is vibrated by the vibrating means TPE2, the ball 51 deviates from the opening of the tube 30b to occupy unstable positions 52, 53 where it is laterally retained by the guide means 55. The liquid 5b in the tank 1b can then flow into the tube 30b. The position of the guide means 55 is such that when the tube 30b no longer vibrates, the ball 51 falls on the opening of the tube. For this purpose, the guide means 55 are positioned to prevent the ball 51 from moving laterally more than half the inside diameter of the tube 30b from its rest position where it closes the opening 33b. Thus, the guide means 55 are arranged at a distance from the central axis of the opening 33b of the tube 30b, less than the sum of the inside diameter of the tube and the diameter of the ball.

The filling control device shown in FIG. 3 thus makes it possible to control the flow of liquid in the tube 30b at a very low cost. This device can easily be adapted to operate with a non-horizontal tube opening, for example by implementing a low restoring force acting on the ball so that it returns to a position closing the opening of the tube in the absence excitation of the tube.

FIG. 4 represents a nebulization device NBCT2 according to another embodiment. The NBCT2 device differs from the NBCT1 device in that the tube 30b is arranged substantially horizontally. The control device 12b can then be omitted, the flow of the liquid 5b can be prevented by the capillary retention capacity of the tube 30b if the level of the surface of the liquid 5b in the tank 1b is not too far from the level of the tube 30b. When the tube 30b is excited, the meniscus formed at the interface between the liquid 5b and the liquid contained in the reservoir 10 is expelled from the tube, which activates a suction of the liquid 5b in the tank 1b because of the tension forces superficial acting to restore the meniscus. The tube 30b then behaves like a micro pump. The length of the tube that enters the reservoir 10 may be about 8 mm when the tube 30b has a total length of 27 mm.

The device NBCT2 can operate substantially in the manner illustrated in FIG. 2, except that the activation of the signal Sv2 also triggers the flow of the liquid 5b in the intermediate tank 10. FIG. 5 shows a nebulization device NBCT3 according to a another embodiment. The device NBCT3 differs from the device NBCT1 in that the tanks 1a and 10 are replaced by a single tank 1 to ^{1 in} the form of a bird feeder, so as to remove the filling control device 12a. Thus the tank 1 has' a closed portion 3a (not subject to atmospheric pressure) and an open portion 10a (subjected to atmospheric pressure) in communication with a siphon 4a with the volume of the part 3a. Part 3a has a relatively large volume acting as a main reservoir for containing the liquid 5a. The open part 10a of smaller volume acts as an intermediate reservoir. When the level of the liquid in the portion 10a is low enough to allow air into the portion 3a through the siphon 4a, the liquid in the portion 3a flows into the portion 10a until a certain level of equilibrium is reached. just above the upper level of the siphon 4a.

It should be noted that if the liquid 5b is lighter than the liquid 5a and if the liquid 5b is introduced into the tank 10 in a small amount relative to the liquid 5a, the liquid 5b can not enter the part 3a. This case usually occurs when the tank 1a is filled with water and the tank 1b with one or more perfumes or essential oils.

The ejection nozzle 32b of the mixing tube 30b is immersed in the liquid in the part 10a and the upstream opening of the nebulization tube 30 communicate with part 10a. The filling control device 12b can be made using the ball 51 as shown in FIG. 3.

The NBCT3 device operates in substantially the same manner as the NBCT1 device. A substantially homogeneous mixture is obtained in the tank portion 10a in the same manner as in the NBCT1 device. However, the opening of the control device 12b and the activation of the signals Sv1 and Sv2 are performed substantially simultaneously if it is desired that the concentration of the liquid 5b in the mixture obtained in the part 10a remains constant. FIG. 6 represents a nebulization device NBCT4 according to another embodiment. The NBCT4 device differs from the NBCT1 device in that the tank 1b is not connected to the intermediate tank 10 by a capillary tube 30b, but only by a single pipe 3b. The NBCT3 device therefore does not include TPE2 vibrating means. Moreover, the nebulization tube 30 is replaced by a capillary nebulization tube 40 bevelled at each of its two end openings 42, 43. The tube 40 passes through the wall of the tank 10 into a zone of the tube where a node is formed. vibration when excited by the vibrating medium TPE1, so as to limit the loss of vibration energy. The vibrated tube 40 can thus ensure both the nebulization of liquid in the air, and cause the agitation of the two liquids in the reservoir 10 if the upstream opening 43 of the tube 40 is near or in the vicinity of a contact zone between the two liquids 5a, 5b. This condition is achieved in particular if the reservoir 10 is sufficiently small, typically 7 to 10 mm 2 of surface and 6 to 10 mm in height. Of course, the dimensions of the intermediate tank 10 may exceed these values since the vibration of the tube causes the agitation of the two liquids and thus the formation of a mixture. It can indeed be observed that the closer the end 43 of the tube 40 is to the contact zone between the two liquids, the faster the emulsion is formed. Conversely, when it is located beyond a certain distance from the contact zone between the two liquids, the end 43 only agitates one of the two liquids and therefore does not cause the formation of a fluid. mixed.

The agitation of the liquids by the portion of the tube 40 in the reservoir 10 leads to the formation of a substantially homogeneous mixture at least adjacent to the upstream opening 43 of the tube 40. Due to the use of a single capillary tube for agitating the liquids in the tank 10 and nebulizing them in the air, the mixture obtained in the vicinity of the upstream opening 43 , is nebulized as it is produced. FIG. 7 illustrates a sequence P2 of operation of the nebulization device NBCT4. In an initial state, the fill control devices 12a and 12b are in the closed state, and the excitation signal Sv1 is in an inactive state. At a time t10, the CNCT circuit triggers a filling cycle of the tank 10 by controlling the opening of the devices 12a and 12b to introduce the liquid 5a, 5b contained in the tanks 1a, 1b in a desired proportion. When a certain amount of liquid 5a and a quantity of liquid 5b have been introduced into the tank 10 at time t11, the CNCT circuit controls the closure of the devices 12a, 12b. The upstream opening 43 of the tube 40 is then immersed in the heaviest liquid 5a or 5b in the tank 10, if the two liquids 5a, 5b are immiscible with each other. At the instant t12, a few milliseconds after the instant t11, the CNCT circuit controls the excitation circuit EXCT to activate the signal Sv1, in order to vibrate the tube 40, and thus to trigger the mixing of the two liquids and a nebulization cycle. The liquids 5a, 5b are agitated violently in the vicinity of the opening 43 of the tube 40. At a time t13, the CNCT circuit terminates the nebulization cycle by deactivating the signal Sv1 when the entire mixture in the tank 10 has been nebulized . After a certain rest time after the end of the nebulization cycle, the CNCT circuit performs a new filling cycle of the tank 10, as at time t10.

It may be preferable to maintain the upstream opening 43 of the tube 40 still immersed. For this purpose, the reservoir 10 can be filled between two nebulizations at its maximum level. If the duration of the rest period between two nebulization cycles is very long, the constituents of the mixture inside the tube 40 can separate, producing a non-homogeneous nebulization in concentration at the next nebulization cycle. To avoid this disadvantage, a purge phase of the tube 40 can be provided at the end of each nebulization cycle before filling the reservoir 10 again. It should be noted that the concentration of active product of the nebulized mixture varies during a nebulization cycle because the mixture of the two liquids is made during nebulization. Thus, at the beginning of the nebulization cycle, the nebulized liquid comprises substantially only liquid 5a. Then, the proportion of liquid 5b nebulized increases rapidly to reach the desired concentration corresponding to the ratio between the volumes of the liquid 5a, 5b in the tank 10. However, the average concentration over several nebulization cycles of active product of the nebulized mixture remains constant if the two liquids 5a, 5b are always introduced in the same proportions in the tank 10 at each filling cycle of the tank 10. Note also that the two liquids 5a, 5b are not necessarily introduced into the tank 10 simultaneously.

Several nebulization cycles can be carried out between instants t12 and t13 (without refilling the tank 10), the number of nebulization cycles depending only on the volume of the tank 10, and the amount of nebulized liquid at each nebulization cycle, knowing that the liquids are necessarily agitated in the tank 10 during nebulization cycles. The NBCT4 device may have another mode of operation based on the fact that the vibration regime necessary for the nebulization is more restrictive than that for agitating the liquids in the reservoir 10. Thus, the tube 40 is vibrated according to a mode and at a frequency that provides a mixture of liquids 5a, 5b, but which does not produce nebulization. The vibration frequency for mixing liquids can thus be between 100 and 150 kHz. When a sufficient amount of mixture is obtained in the tank 10, for example when all the liquids in the tank 10 are mixed, the mode of excitation of the tube 40 is modified to produce a nebulization. The tank 1a 'shown in Figure 5 can also be implemented in the NBCT4 nebulizing device of Figure 5, replacing the tanks 1a and 10 and the filling control device 12a. Thus, FIG. 8 represents an embodiment of a nebulization device NBCT5 that differs from the device NBCT3 in that the mixing capillary tube 30b has been replaced by a simple channel, and the nebulization tube 31 has been replaced by the capillary tube 40 ensuring both the agitation of the liquids in the portion 10a of the tank 1a 'and the nebulization of the mixture in the air. For this purpose the tube 40 can be placed in an inclined position to pass a rim of the portion 10a while having its upstream opening 43 immersed in the tank portion 10a. The filling control device 12b may comprise a dropper to precisely adjust the liquid supply 5b in the part 10a. In a simplified variant, the dropper can be purely manual, the liquid 5b being housed in a bottle with a small upper opening and returned above the portion 10a, to deposit drops of active liquid on the surface of the liquid 5a (by example of water).

The tube 40 can also be implemented in the devices NBCT1, NBCT2 and NBCT3, so as to agitate, with the tube 30b, the liquids in the reservoir 10, 10a, and thus increase the efficiency of mixing. Of course, the previously described nebulization devices can also work with liquids miscible with each other. Simply, the mixture obtained by stirring the two liquids will be stable. These devices can also be used to diffuse mixtures of water and oils in the presence of surfactants, with a proportion of surfactants that may be below the threshold to obtain a stable emulsion, to simply improve the stability of the mixture while being more respectful of regulations and health.

If the liquid to be mixed with the active product is water, the previously described nebulization devices may be associated with a fan to also provide a cooling function. The nebulization devices described above also have the advantage of being able to also provide a hygrometry control function independently of the nebulization function of active products in the air. Indeed, as the concentration of active product of the nebulized mixture can be adjusted, it is possible to provide water diffusion cycles without active product, in order to increase the hygrometry of the air. For this purpose, the nebulizing device may also comprise a humidity sensor which can trigger additional cycles of water diffusion when the ambient humidity measured by the sensor is insufficient. The nebulization devices described above can also be adapted to the cleansing of the hands, and more generally, of the skin or other surfaces. These devices then have the advantage of avoiding the use of a solid applicator, which is particularly advantageous for the treatment of burns. They also have the advantage of controlling the concentration of active product of the diffused liquid. They do not require transport of packages containing a large weight of excipients, unlike aerosol cans. Moreover, the problem of the stability over time of the compositions to be diffused comprising in particular water does not arise, since the mixing is carried out just before its diffusion. The nebulization devices described above are therefore perfectly suited to the vaporization of concentrated luxury perfumes without the use of alcohol, which has been sought for decades. It should be noted that the filling control device shown in FIG. 3 can be used to close the inlet of the nebulization tube 31. For this purpose, the nebulizing tube can be arranged vertically or be shaped so that its upstream opening be horizontal. The filling control device shown in FIG. 3 may also be used in any other device which is not necessarily intended for stirring liquids, producing a mixture of liquids, or producing a nebulization. Thus, the present application also seeks to independently protect a valve device controlling the closure of a closed circular opening by a spherical or substantially conical shaped piece and capable of being vibrated to clear the piece of the opening, the part cooperating with guide means to prevent it from moving laterally from the axis of the opening by a distance greater than the radius of the opening. The piece and the guide means may have other shapes as soon as the piece is systematically at rest in the position where it closes the opening, and deviates from this rest position when the opening is subjected to vibration.

It will be apparent to those skilled in the art that the present invention is susceptible of various embodiments and applications. In particular, the invention is not limited to the use of a capillary tube vibrating circular section to stir liquids. The tube 30b is not necessarily capillary and may have the shape of a rod having a cross section of any shape, not necessarily circular. The end of the tube agitating the liquids is not necessarily bevelled, but may have a shape more suitable for stirring liquids or have fins for this purpose.

Furthermore, the invention is not limited to liquid mixing applications for nebulizing products in the air. The present invention more generally applies to stirring liquids in a small quantity, for example to produce a mixture of fuel such as gas oil and another miscible or non-miscible liquid, such as water, at the inlet of an internal combustion engine.

In the application of the invention to the mixture alone (not followed by a nebulization) of liquids, the mixing device can of course be applied to any liquids whether they are harmful or not to the skin, respiratory tract and the environment.

In the application of the invention to nebulization, the nebulizing head is not necessarily in the form of a capillary tube coupled to a vibrating member. Any other nebulization head that can be fed by an intermediate reservoir may be suitable for nebulizing an unstable mixture such as an emulsion. Thus, it may be envisaged to use a fogging head such as those described in patent EP 0 714 709 comprising ejection channels subjected to vibrations, or using piezoelectricity or electrostatic or the Venturi effect. Venturi diffusion technology is today mainly used in nebulization devices designed to treat very large volumes. The invention provides these devices with a technical advantage resulting from the possibility of diffusing any active product, without having to diffuse into the air large quantities of solvents other than water, which could be harmful to the environment. environment. The invention makes these systems economical because the volumes treated being important, the quantities of active products and diffused solvents are also. If water is used as a solvent, the economy is important.

Claims

A method of mixing liquids, comprising steps of contacting liquids (5a, 5b) with one another in a reservoir (10, 10a), and agitating the liquids to obtain a substantially homogeneous mixture, characterized in that it comprises steps of circulating at least one of the liquids in a capillary tube (30b, 40) having a bevelled end (32b, 43) immersed in the vicinity of a contact zone between the liquids (5a, 5b ), and vibrating the tube by means of a piezoelectric vibrating member (TPE2, TPE1) to stir the liquids.

2. Method according to claim 1, wherein the contacting of the liquids (5a, 5b) is carried out substantially simultaneously with the stirring of the liquids, by introducing a first of the liquids into a second of the liquids by the capillary tube (30b). driven in vibration.

3. The method of claim 1, wherein the contacting of the liquids (5a, 5b) is carried out by introducing the liquids into a reservoir (10, 10a), and stirring of the liquids is performed after the introduction of the liquids. in the tank.

4. Method according to one of claims 1 to 3, wherein the tube

(30b, 40) is disposed substantially vertically or substantially horizontally.

5. Method according to one of claims 1 to 4, wherein the liquids (5a, 5b) are immiscible with each other, one of the two liquids may comprise water.

6. A method for nebulizing in air a first liquid (5a) and a second liquid (5b) comprising an active product, characterized in that it comprises mixing steps of the two liquids (5a, 5b) according to the process according to one of claims 1 to 5, to obtain a substantially homogeneous mixture, and nebulization of the mixture.

7. The method of claim 6, wherein the mixture of liquids (5a, 5b) is carried out simultaneously with the nebulization of the mixture.

8. Method according to one of claims 6 and 7, wherein the mixture of liquids (5a, 5b) is formed in an intermediate reservoir (10, 10a) which can contain at most a quantity of nebulized mixture in one or a few cycles of nebulization.

9. Method according to one of claims 6 to 8, wherein the nebulization is performed by another capillary tube (31) which may be identical to the capillary tube (30b) provided for stirring the liquids.

10. Method according to one of claims 6 to 8, wherein the nebulization is performed by a beveled end (42) of the capillary tube

(40), and the mixing of the liquids (5a, 5b) is effected by another bevelled end (43) of the capillary tube.

11. Liquid mixing device (5a, 5b), comprising a reservoir (10, 10a) in which liquids are brought into contact, characterized in that it comprises a capillary tube (30b, 40) having a bevelled end ( 32b, 43) arranged to be immersed in the vicinity of a contact area between the liquids, and a piezoelectric vibrating member (TPE2, TPE1) coupled to the tube for vibrating the tube to agitate the liquids in the reservoir (10). , 10a).

12. Device according to claim 11, wherein the capillary tube (30b) is arranged to introduce one of the liquids into the reservoir (10, 10a).

Device according to claim 11 or 12, comprising a control circuit (CNCT) configured to trigger the introduction of one of the liquids (5a, 5b) into the reservoir (10, 10a) through the capillary tube (30b). after vibrating the capillary tube.

14. Device according to one of claims 11 to 13, wherein the tube (3Ob ₁ 40) is disposed substantially vertically or substantially horizontally.

15. Device according to one of claims 11 to 14, wherein the capillary tube (30b) comprises an upstream opening (33b) liquid inlet which is closed by a part (51) which deviates from the opening upstream under the effect of vibrations, when the capillary tube is vibrated to introduce the liquid (5b) into the reservoir (10, 10a).

16. Device for nebulizing in air a first liquid (5a) and a second liquid containing an active product (5b), characterized in that it comprises: a mixing device according to one of claims 11 at 14, to obtain a substantially homogeneous and unstable mixture of the two liquids in an intermediate reservoir (10, 10a), and a nebulizing head (30, 40) for nebulizing the mixture.

17. Device according to claim 16, wherein the nebulizing head (30) comprises a capillary nebulization tube (31, 40), one end of which forms a nebulizing nozzle (32), a vibrating member (TPE1) for driving the head. vibration nebulizer, for ejecting droplets of liquid into the air in a nebulizing jet, and an excitation circuit (EXCT) for applying to the vibrating member an excitation signal (Sv1) during each nebulization cycle.

18. Device according to claim 17, wherein the capillary nebulization tube (31) and the mixing capillary tube (30b) are identical and are vibrated by vibrating members (TPE1, TPE2) identical.

The device of claim 17, wherein the capillary nebulizing tube (40) comprises a beveled end (43) arranged to agitate the liquids in the intermediate reservoir (10, 10a) to forming a mixture, and another beveled end (42) to nebulize the mixture in the air, when it is vibrated.

20. Device according to one of claims 16 to 19, wherein the intermediate reservoir (10, 10a) has a volume that can contain at most the volume of nebulized mixture in one or a few nebulization cycles.

21. Device according to one of claims 16 to 20, wherein the intermediate reservoir (10a) is connected by a siphon (4a) to a main reservoir (3a) closed, so that the level of liquid in the reservoir (10a) is substantially constant.

22. Device according to one of claims 16 to 21, comprising a filling control device (12a, 12b) for controlling the proportions of liquids (5a, 5b) in the intermediate reservoir (10, 10a).