CN107949672B

CN107949672B - Liquid atomizer comprising a piezoelectric element and iron comprising such an atomizer

Info

Publication number: CN107949672B
Application number: CN201680051467.6A
Authority: CN
Inventors: 多米尼克·格吕斯; 让-路易·孔波
Original assignee: SEB SA
Current assignee: SEB SA
Priority date: 2015-09-14
Filing date: 2016-09-13
Publication date: 2020-05-22
Anticipated expiration: 2036-09-13
Also published as: CN107949672A; FR3040897B1; EP3350367A1; EP3350367B1; WO2017046500A1; FR3040897A1

Abstract

The invention relates to a liquid atomizer (6) comprising a piezoelectric element (8) which is attached to an amplifying nozzle (9) which is moved in an oscillating manner, the nozzle comprising a cavity (90) containing the liquid to be atomized, the nozzle (9) comprising a first portion (92) housing the piezoelectric element (8) and a second portion (93) different from the first portion (92), the second part being mechanically and acoustically connected to a micro-perforated film (91) closing one side of the cavity (90), characterized in that the cavity (90) is supplied with liquid from the container (5) by means of a pump (51), the pump having a flow rate which is greater than the atomizing amount of the atomizer (6) in operation, and the spout (9) comprises at least one outlet orifice (94) connecting the cavity (90) to a deflector duct (66) directed towards the container (5).

Description

Liquid atomizer comprising a piezoelectric element and iron comprising such an atomizer

Technical Field

The present invention relates to a liquid atomizer comprising a piezoelectric element fixed to an amplifying nozzle moving in oscillation, said nozzle comprising a cavity containing a liquid to be atomized, and more particularly to an atomizer wherein the nozzle is mechanically and acoustically connected to a micro-perforated membrane closing one side of said cavity.

Background

From patent application FR2908329 an ultrasonic liquid atomizer is known, which comprises a piezoelectric element fixed to an amplifying nozzle moving in oscillation, said nozzle comprising an end connected to a micro-perforated membrane which closes a cavity formed inside the nozzle containing the liquid to be atomized.

Such atomizers have the advantage of vibrating in a longitudinal mode and allow a certain amount of liquid to be atomized instantaneously, very precisely and with droplets of regular size. Furthermore, the height of the water defined above the membrane and the presence of a container sealed to the air allow to avoid dripping problems through the membrane when the nebuliser is stopped.

However, such a liquid atomizer has a disadvantage in that it cannot be operated for a long time because the water container has a limited capacity. However, the volume of the container above the microperforated film cannot be simply increased because such an increase in volume would result in an increase in the height of the water column above the film, thereby creating an undesirable flow of water droplets through the film when the atomizer is stopped.

Disclosure of Invention

It is therefore an object of the present invention to provide a liquid atomizer comprising an oscillating moving amplification nozzle comprising a cavity containing a liquid to be atomized enclosed by a micro-perforated membrane, which atomizer can be operated for a long time, even continuously, and without dripping problems when atomization is stopped. It is a further object of the invention to provide an iron equipped with such an atomizer.

To this end, the object of the invention is a liquid atomizer comprising a piezoelectric element fixed to an amplifying nozzle moving in oscillation, said nozzle comprising a cavity containing a liquid to be atomized, said nozzle comprising a first portion housing said piezoelectric element and a second portion different from said first portion, said second portion being mechanically and acoustically connected to a micro-perforated membrane closing one side of said cavity, characterized in that said cavity is supplied by liquid from a container at a flow rate greater than the atomization of said atomizer in operation, and in that said nozzle comprises at least one output orifice connecting said cavity to a deflector duct directed towards said container.

Preferably, the output aperture is sufficiently remote from the first portion housing the piezoelectric element so as not to interfere too much with the vibrational operation of the nebulizer. The output aperture is also advantageously sufficiently remote from the microperforated film that the flow of liquid through the output aperture does not interfere with the operation of the microperforated film.

Such atomizers have the advantage of having a micro-perforated film fixed to a portion of the nozzle vibrating in a longitudinal mode, which allows to produce an atomization with little dispersion in the diameter of the droplets.

According to another characteristic of the invention, the cavity is supplied by the liquid from the container by means of a pump operating continuously during the liquid nebulization phase of the nebulizer.

This continuous operation of the pump has the advantage of cleaning the upper surface of the film and avoiding unwanted deposition of particles.

According to another characteristic of the invention, the pump also operates intermittently or continuously outside the liquid atomization phase of the atomizer.

According to another characteristic of the invention, the piezo-atomizer vibrates in a longitudinal mode in the range from 50kHz to 200 kHz.

According to another characteristic of the invention, the nozzle has a cross-sectional variation between a first portion supporting the piezoelectric element and a second portion connected to the microperforated film.

This variation of the cross-section has the advantage of amplifying the longitudinal ultrasonic waves emitted by the piezoelectric element and allowing a certain level of amplitude, so that the scale deposited on the micro-perforated film is removed.

According to another feature of the invention, the micro-perforated film is fixed to the longitudinal end of the nozzle.

According to another characteristic of the invention, the spout has an axis of rotation and comprises at least two output holes arranged symmetrically with respect to the axis of rotation, the output holes communicating with a discharge chamber connected to the deflector duct towards the container.

This arrangement of the output orifice has the advantage of not interfering too much with the vibration mode of the nozzle and allows to obtain a vibration mode of the nozzle suitable for obtaining an atomization with droplets having a monodisperse intermediate diameter centered in a range that can be between 20 μm and 100 μm.

According to another characteristic of the invention, the microperforated film is connected to the end of the cylindrical body of the spout and the output orifice is arranged on the cylindrical body.

According to another characteristic of the invention, the microperforated film is made of electromagnetic forming stainless steel and is covered with a release coating. By release coating is meant that the droplets form an angle of greater than 90 on the coating. Such a release coating allows to limit the adhesion of scale on the membrane.

According to another characteristic of the invention, the microperforated film comprises holes having a diameter of less than 40 μm, said holes being more than 400 μm away from each other. This configuration allows to reduce the dripping problem through the membrane.

According to another characteristic of the invention, one or more of the output orifices are distanced from the microperforated film by a height h that is less than 10mm and preferably of the order of 2 mm.

This feature allows to eliminate the dripping problem and to obtain an optimal operation of the atomizer during the start-up and stop phases.

According to another characteristic of the invention, one or more of the output holes have a diameter greater than or equal to 2 mm.

According to another characteristic of the invention, the liquid atomizer comprises a supply chamber communicating on the one hand with the cavity and on the other hand with a water inlet conduit connected to the pump, the supply chamber comprising an air inlet hole.

According to another characteristic of the invention, the air intake comprises filtering means which prevent the entry of foreign bodies into the supply chamber.

According to another characteristic of the invention, the cavity is fed with liquid from the container by a supply circuit comprising a water filter and a diffusion means of the antibiotic product, such as a colloidal agent. This feature allows to avoid the production of algae in the cavity.

The invention also relates to an iron comprising a heated soleplate on which a housing is mounted, said housing containing a reservoir, and said iron comprising a liquid atomizer as described above.

According to another feature of the invention, the atomizer is carried by the housing and allows wetting of a treatment area located outside the bottom plate.

According to another characteristic of the invention, the atomizer atomizes the liquid at a flow rate of between 6 and 20gr/min, and preferably about 9 gr/min.

This feature allows to obtain a well performing wetting for ironing the laundry, without the wetting being so great as not to create difficulties for drying the laundry when the soleplate of the iron passes.

According to another characteristic of the invention, the atomizer spreads the mist with droplets having a mean diameter comprised between 30 and 60 μm.

This feature allows to obtain a mist which at the same time is less dissipative and does not form water spots on the garment to be ironed.

According to another characteristic of the invention, the atomizer has a diffusion zone suitable for wetting a treatment zone extending along both edges of the front tip of the base plate.

This feature allows for wetting of the garments on both sides of the front tip of the sole plate by a single atomizer.

According to another characteristic of the invention, the holes of the microperforated film are distributed along a V-shape.

This feature allows to obtain a spreading range of the V-shaped droplets that fit the front tip of the bottom plate.

Drawings

The objects, features and advantages of the invention will be better understood from the following description of a particular embodiment thereof, given by way of non-limiting example with reference to the accompanying drawings, in which:

figure 1 is a perspective view of an iron equipped with a liquid atomizer according to an embodiment of the present invention;

figure 2 is a side view of the ironing apparatus of figure 1 schematically showing a reservoir and a pump allowing the supply of the atomizer;

fig. 3 is a longitudinal section of the atomizer with which the iron of fig. 1 is equipped;

FIG. 4 is a top view of the microperforated film.

Detailed Description

Only the elements necessary for an understanding of the present invention are shown. To facilitate reading of the drawings, like elements are provided with like reference numerals between the different drawings.

Fig. 1 shows a steam iron 1, which as is known comprises a soleplate 2 in thermal contact with a heating body, not shown in the figures, which soleplate contains an electrical resistance having a power of about 1600W, the iron comprising an evaporation chamber dimensioned so as to generate a steam flow of about 20gr/min for diffusion through holes formed in the soleplate 2, the temperature of the soleplate 2 being controlled by a thermostat, the nominal temperature of which can be modified by the user by means of an adjustment button 3.

Mounted on the soleplate 2 is a plastic housing 4 which integrates a gripping handle 40 and comprises a base 41 with which the iron can be placed upright during non-ironing working phases, the base 41 being advantageously equipped with a connector, not shown in the figures, which allows the electric connection of the iron to a charging base.

According to fig. 2, the housing 4 contains a water container 5, which is schematically shown by a dashed line, and the housing 4 comprises a tapering front end portion supporting atomizing means consisting of an ultrasonic liquid atomizer 6, which generates droplets having a diameter size mainly between 30 μm and 60 μm, which allows wetting of the atomizing area located in front of the front tip of the bottom plate 2.

Preferably, the iron 1 further comprises a scraping element 10 extending outside the heating sole plate 2 and spaced from the edge of the sole plate 2 by about 3mm, which allows the droplets to mechanically enter the interior of the fabric to be ironed before the heating sole plate 2 passes through the fogging area. Such a scraping element 10 is described in detail in patent application FR1158318 filed by the applicant.

According to fig. 3, the atomizer 6 comprises a hollow cylindrical housing 60 of plastic, comprising side projections 61 equipped with bores capable of receiving fixing screws for fixing the atomizer 6 to the housing 4 of the iron, the housing 60 comprising a receiving chamber 62 in which the electromechanical atomizer generator 7 is arranged, which electromechanical atomizer generator operates in the range 50kHz to 200 kHz.

The housing chamber 62 comprises an open lower end 62A and an opposite end comprising an opening 62B communicating with a supply chamber 63 located above the housing chamber 62 when the iron is placed with the soleplate 2, the supply chamber 63 comprising a lateral hole 63A closed at the upper end by a cover 64 and forming a vent hole ensuring the supply chamber 63 is at atmospheric pressure, the vent hole 63A being advantageously equipped with a filter, not shown in the figures, which prevents foreign objects from entering the supply chamber 63.

According to figures 2 and 3, the supply chamber 63 receives water from the container 5 through a supply circuit comprising a water intake conduit 50 passing through a cover 64, the water intake conduit 50 being connected to a pump 51, the operation of which is controlled by means of a push button 11, shown in figure 2, arranged in front of the handle 40. Preferably, the supply circuit further comprises a water filter and an antibiotic diffusing means, such as a colloidal agent, not shown in the figures.

As shown in fig. 3, the nebulization generator 7 comprises a piezoceramic 8 which is affixed to an amplifying nozzle 9 moving in oscillation, which nozzle is traversed by a cavity 90 containing the liquid to be nebulized, the cavity 90 extending along the axis of rotation R of the nozzle 9 and being closed at one end by a microperforated film 91 having a small thickness of between 20 μm and 200 μm and being mechanically and acoustically connected to the nozzle 9.

Piezoelectric ceramic 8 is supplied with current by a supply circuit, not shown in the figures, known per se, which supplies an alternating current to the terminals of piezoelectric ceramic 8, which is supplied with current only when push-button 11 is actuated by the user.

Preferably, the nozzle 9 comprises a shoulder 92 on which the piezoceramic 8 is glued, and the nozzle 9 comprises a cylindrical body 93 having a smaller cross section than the longitudinal ends to which the microperforated film 91 is mechanically and acoustically fixed, for example by gluing, soldering, embedding or welding.

By way of example, the nozzle 9 has a diameter of about 16mm at the shoulder 92 supporting the piezoceramic 8 and a diameter of about 8mm at the height of the cylindrical body 93.

Preferably, the micro-perforated film 91 has a thickness of 50 μm and comprises a set of pores having a diameter of less than 40 μm, said pores being more than 400 μm away from each other. The micro-perforated film 91 is advantageously realized by electro-magnetically formed nickel or electro-magnetically formed stainless steel, preferably coated with gold, in order to resist the adhesion of scale.

As an example, the micro-perforated film 91 has 70 holes with a diameter of 35 μm, preferably distributed according to a V-shape, as shown in fig. 4, which allows to obtain a droplet spreading range of a V-shape adapted to conform to the shape of the front tip of the base plate 2, by means of a single atomizer.

The cavity 90 has an open end opposite the microperforated film 91 that communicates with the supply chamber 63 through the opening 62B so that water present in the supply chamber 63 flows into the cavity 90.

More specifically, according to the invention, the pump 51 supplying the cavity 90 has a flow rate greater than that of the atomiser 6 when in operation, and the nozzle 9 preferably comprises two output holes 94 aligned along a horizontal axis and arranged symmetrically with respect to the axis of rotation R of the nozzle 9, each output hole 94 opening into an annular discharge chamber 65 surrounding a cylindrical body 93 of the nozzle 9 and communicating with the deflector duct 66 towards the container 5.

As an example, the nebuliser 6 has a water nebulisation flow rate of about 9gr/min in order to optimally moisten the fabric to be ironed, and the pump 51 supplies water to the supply chamber 63 at a flow rate of about 12 gr/min.

Preferably, the output hole 94 has a diameter greater than or equal to 2mm in order to allow the excess water delivered by the pump 51 to flow well towards the deflector duct 66, the output hole 94 being distanced from the micro-perforated film 91 by a height h of about 2mm in order to permanently have a water film of small height covering the micro-perforated film 91.

The operation of an iron equipped with such an atomizer 6 will now be described.

During ironing, when the user wishes to moisten the fabric in order to remove difficult or false folds, the user presses the button 11 so as to cause simultaneously the activation of the pump 5 and the electrical excitation of the piezoceramic 8, which therefore generates a vibrating movement amplified by the cylindrical body 93 having a smaller diameter, as described in more detail in patent application FR 2908329.

This causes the micro-perforated film 91 to vibrate in a longitudinal mode and the micro-water droplets to be ejected through the micro-perforated film 91 at a flow rate of about 9gr/min in a V-shaped range conforming to the shape of the front tip of the soleplate 2, the cavity 90 of the nozzle 9 being supplied with a large flow rate of water, so that the micro-perforated film 91 is permanently covered with a constant volume of water, thereby allowing a uniform atomized flow rate, the excess volume of water being re-sent towards the container 5, i.e. through the output aperture 94, and then through the deflector conduit 66, as schematically illustrated by the arrows in fig. 3.

The droplets thus emitted by the nebuliser 6 are deposited on the surface of the fabric to be ironed, then saturate the fabric by the flat application of the scraping element 10 as the iron advances, which causes wetting and therefore relaxation of the fabric fibres, after which the hot soleplate 2 of the iron dries the fabric, which allows a perfect ironing to be obtained.

When the user no longer wishes to have a spray, he releases the button 11, which simultaneously causes the stopping of the pump 51 and the electrical activation of the piezoceramic 8, so that the emission of the droplets is momentarily interrupted without the risk of undue dripping through the microperforated film 91, since a small height of water is maintained above the microperforated film.

Such an atomiser 6 therefore has the advantage of being able to operate continuously until the water in the container 5 is exhausted, the circulation of the excess water delivered by the pump 51 having the advantage of stirring and refreshing the water above the micro-perforated film 91, which allows to drain possible dirt on the micro-perforated film 91 and allows to improve the cooling of the micro-perforated film 91 during prolonged use of the atomiser 6.

Such an atomiser also has the advantage of consuming very little energy and producing very regular droplet sizes, which makes it more suitable for use on low power consumption irons, and in particular cordless irons.

Finally, this atomizer, which comprises a nozzle vibrating in a longitudinal mode, has the advantage of having a spreading range of the droplets, which is directly dependent on the distribution of the holes on the microperforated film. Thus, a spread of droplets of a V-shape adapted to conform to the shape of the front tip of the soleplate is obtained, so that the fabric is wetted in front of and at the side of the front tip of the soleplate, without droplets being sprayed on the housing of the iron.

The invention is of course not limited to the foregoing embodiments shown and described, given by way of example. Modifications are possible, in particular in the combination of different elements or by technical equivalents, without exceeding the scope of protection of the invention.

Thus, in an embodiment variant of the invention, the nozzle may comprise only a single output orifice communicating with the deflector duct.

In a variant embodiment of the invention, which is not shown, the outlet opening can therefore have a non-circular passage cross-section and have smaller dimensions.

Thus, in an embodiment variant of the invention, the pump can also operate continuously or intermittently when the piezoceramic is not powered, i.e. outside the phase in which the atomizer atomizes the liquid. Thus, the pump operates as soon as the iron is electrically connected to the grid. This variant of embodiment has the advantage of ensuring continuous cleaning of the upper surface of the membrane by means of water circulation.

Claims

1. A liquid atomizer (6) comprising a piezoelectric element (8) fixed on an amplifying nozzle (9) which moves in oscillation, the nozzle comprising a cavity (90) containing the liquid to be atomized, the nozzle (9) comprising a first portion (92) housing the piezoelectric element (8) and a second portion (93) different from the first portion (92), the second part being mechanically and acoustically connected to a micro-perforated film (91) closing one side of the cavity (90), characterized in that said cavity (90) is supplied by liquid from the container (5) at a flow rate greater than the nebulization volume of said nebulizer (6) in operation, and the spout (9) comprises at least one outlet orifice (94) connecting the cavity (90) to a deflector duct (66) directed towards the container (5).

2. A liquid atomizer (6) according to claim 1, characterized in that the cavity (90) is supplied by liquid from the container by means of a continuously operating pump (51) during a liquid atomization phase of the atomizer.

3. A liquid atomizer (6) according to any one of claims 1 to 2, characterized in that the piezoelectric atomizer vibrates in a longitudinal mode in the range of 50kHz to 200 kHz.

4. A liquid atomizer (6) according to any of claims 1 to 2, characterized in that the nozzle tube (9) has a cross-sectional change between the first portion (92) supporting the piezoelectric element (8) and the second portion (93) connected to the microperforated film (91).

5. A liquid atomizer (6) according to any of claims 1 to 2, characterized in that the micro-perforated film (91) is fixed to the nozzle tube (9) at its longitudinal ends.

6. A liquid atomizer (6) according to any of claims 1 to 2, characterized in that the nozzle tube (9) has an axis of rotation and comprises at least two output holes (94) symmetrically arranged with respect to the axis of rotation, the output holes (94) communicating with a discharge chamber (65) connected to the deflector conduit (66) towards the container (5).

7. A liquid atomizer (6) according to claim 6, characterized in that the micro-perforated film (91) is connected to an end of a cylindrical body (93) of the spout (9) and the output orifice (94) is arranged on the cylindrical body (93).

8. A liquid atomizer (6) according to any of claims 1 to 2, characterized in that one or more of said output orifices (94) are distanced from said microperforated film (91) by a height h, said height h being smaller than 10 mm.

9. A liquid atomizer (6) according to claim 8, characterized in that the height h is about 2 mm.

10. A liquid atomizer (6) according to any one of claims 1 to 2, characterized in that one or more of the output holes (94) have a diameter greater than or equal to 2 mm.

11. Liquid atomizer (6) according to claim 2, characterized in that it comprises a supply chamber communicating on the one hand with the cavity (90) and on the other hand with a water inlet conduit (50) connected to the pump (51), the supply chamber comprising an air inlet hole.

12. Liquid atomizer (6) according to claim 11, characterized in that the air inlet comprises a filter device which prevents foreign objects from entering into the supply chamber.

13. A liquid atomizer (6) according to any one of claims 1 to 2, characterized in that the cavity (90) is fed with liquid from the container (5) through a supply circuit comprising a water filter and a diffusion device for an antibiotic product.

14. An iron (1) comprising a heated soleplate (2) on which a housing (4) is mounted, said housing containing a reservoir (5), characterized in that the iron comprises a liquid atomizer (6) according to any one of claims 1 to 13.

15. An iron (1) as claimed in claim 14, characterized in that the atomizer (6) is carried by the housing (4) and allows wetting of a treatment area located outside the soleplate (2).

16. An iron (1) as claimed in claim 14, characterized in that the atomizer (6) atomizes liquid at a flow rate of between 6 and 20 gr/min.

17. An iron (1) as claimed in claim 16, characterized in that the flow rate is approximately 9 gr/min.

18. An iron (1) as claimed in claim 14, characterized in that the atomizer (6) diffuses a mist with droplets having a mean diameter of between 30 μ ι η and 60 μ ι η.

19. Iron (1) according to claim 14, characterized in that the atomizer has a diffusion range adapted to wetting a treatment area extending along both edges of the front tip of the soleplate (2).

20. An iron (1) as claimed in claim 19, characterized in that the holes of the micro-perforated film (91) are distributed along a V-shape.