WO2002022276A1

WO2002022276A1 - Ultrasound humidifier

Info

Publication number: WO2002022276A1
Application number: PCT/BE2001/000159
Authority: WO
Inventors: Marc Michel Alexandre Brodsky
Original assignee: Braybell S.P.R.L.
Priority date: 2000-09-18
Filing date: 2001-09-18
Publication date: 2002-03-21
Also published as: AU2001289436A1

Abstract

The invention concerns an ultrasound humidifier consisting of at least a piezoelectric crystal (3) and a generator (7). The crystal and its generator are incorporated in a small and easily removable housing (2) ensuring impermeability to water and to electromagnetic waves. The housing (2) comprises a cover (20) and a hood (9) and hence can be screwed at the base of a water tank. The housing with the exhausted piezoelectric crystal can easily be unscrewed by the user himself to replace it with a new housing. A metal plate (6) inside the housing (2) ensure its impermeability to electromagnetic waves produced by the generator and enables to easily dissipate the heat produced by the transistor.

Description

Ultrasonic humidifier

The present invention relates to an ultrasonic humidifier consisting of at least one piezoelectric crystal and a generator.

PRIOR ART

An ultrasonic humidifier consists of a tank containing the water to be nebulized. In the bottom of the tank there is provided one or more round openings capable of accommodating piezoelectric cells emitting ultrasound radiation. These cells produce a kind of mini-geyser from which the micro-droplets escape. The latter are carried away by a vertical air current produced by a fan in a chimney-shaped element.

The piezoelectric crystals are fixed under the bottom of the tank. Traditionally, the piezoelectric crystal is mounted in a support of a standard type which was commonly used previously for electronic components such as transistors. This support is fixed to the lower part of the tank by two screws or nuts. The crystal is placed in a special seal which on the one hand seals the water by pressing the seal against the lower wall of the tank and on the other hand imposes the necessary inclination (+ 7 °) so that the fountain produced by vibrations does not fall back on itself which would decrease the efficiency of one humidifier. The crystal is electrically connected to the generator (oscillator) by two wires connected to the lugs placed on the printed circuit, itself located under the tank, in the lower part of the humidifier device.

The average lifespan of a crystal is 10. 000 hours, which means that it must be changed regularly (every year in the event of continuous use)

In addition, the generator, the wires connecting the generator to the crystal and the power cables produce parasitic electromagnetic waves with harmonics of 1.7 MHz, in particular in the FM band.

This means that in order to comply with the standards in force, this assembly must be mounted in a metal casing that protects against electromagnetic waves (Faraday cage). Therefore the replacement of the crystal requires a technical intervention requiring a minimum of know-how, the opening of the case and the risk that after intervention it is no longer impermeable to electromagnetic waves.

Purpose of the invention

The object of the present invention is to allow as simple and economical replacement as possible of the piezoelectric cells. Description of the invention

The object of the present invention is to integrate the crystal and its generator in a small-sized housing ensuring sealing against water and electromagnetic waves while allowing replacement as simple as possible, for example analogous to the replacement of a electric bulb.

The housing can thus be, for example, screwed to the bottom of the water tank and can easily be unscrewed by the user himself in order to replace the housing comprising the cell. The housing with the worn cell is preferably returned to the manufacturer for possible reconditioning.

According to one aspect of the invention, an ultrasonic humidifier is thus proposed in which the or each pair of cells and associated generator is incorporated in a removable housing to be inserted into an opening or recess at the bottom of the water tank. The lower part of the housing includes connection means for the power supply. The upper or lateral part advantageously comprises means for fixing to the bottom of the tank. Other means can however be used to fix the housing in a leaktight manner.

The upper part of one or more housings can thus have edges projecting towards the outside and pressing on a part of the bottom of the tank by means of seals, said upper part comprising an opening in which the piezoelectric crystal is housed. The housing can advantageously be in the form of a threaded cylinder on its outer surface, the thread being complementary to a thread provided in one recess or an opening in the bottom of the tank. According to one embodiment, the upper part of the cylinder is preferably provided with notches accessible by a tightening-loosening tool.

Each box is powered by electrical contacts located under said box and which can be secured to the bottom of an external enclosure receiving the tank.

The humidifier thus comprises a water tank or an aqueous solution and at least one ultrasonic cell at the bottom of said tank, the cell being able, in contact with water, to form a column or fountain of drops and droplets above the surface of said water. According to one embodiment, a stream of air passes horizontally through the base of said column, thus carrying the finest droplets towards an outlet opening. The column is advantageously located in a closed space at the top. According to a preferred variant, the air stream descends along an external face of a deflecting wall present in said space, before crossing horizontally the base of the column.

The invention is described in more detail below, for one or more particular and non-limiting embodiments, with characteristics which can be considered individually or in combination. The housing consists of a tube or cylinder closed in its upper part by a cover whose edges project outwards. This cover is pierced with an opening, for example, ± 18 mm in diameter.

Under this opening is housed a piezoelectric crystal of, for example, ± 20 to 25 mm in diameter which vibrates at 1,700 KHz. The diameter of the opening will be adapted to the size of the crystal. The latter is placed in a rubber seal, preferably perpendicular to the cylinder.

A plate placed inside the tube is fixed to the inside of the cover, for example by screws. It clamps the seal against the cover which ensures the seal is tight. This metal plate also seals the housing against electromagnetic waves produced by the generator.

he generator (oscillator) is fixed to this plate as well as the transistor which ensures 1 evacuation of the heat produced by this one. By conductivity, the entire housing ensures the dispersion of heat.

The housing being housed in an opening in the water tank, the outer edges of the cover are supported by a second seal placed under this edge. This seal will be positioned in a suitable housing, for example a circular groove.

A quick fixing system ensures tight tightening of the case against the interior wall of the water tank while determining the direction and therefore the inclination of the crystal. The fixing can be done by screwing 1 the entire housing at the bottom of the tank or by any other system firmly pressing the housing, in a known manner (eg screw), directly or indirectly, against the outer wall of the bottom of the tank, via an element of sealing.

A cover fixed to the lower part of the tube ensures a passage sealed against electromagnetic radiation from the power supply. It is filtered, in a known manner, using a differential filter and capacitive bulkhead filters which sufficiently reduce the propagation of electromagnetic radiation in the supply network to comply with the standards in force. The housing has good conductive properties in order to form a Faraday cage with respect to radiation, and to ensure efficient dispersion of heat.

According to one aspect of the invention, the housing and its connection to the electrical supply can be disengaged by manipulation of the housing with a loosening tool. The handling is preferably carried out by accessing the bottom of the tank through the upper part of the device.

The housing according to the invention can also be advantageously used for applications relating to water treatment, other than humidification. It is thus possible to apply housings according to the invention for the purification of water in open or semi-open circuits. The bactericidal effect of ultrasound and the anti-deposition effect of limescale are well known, in particularly in the treatment of water from cooling towers. The system can be easily adapted to purify swimming pool water.

The housings can be simply fixed by screwing on a section of pipe with openings adapted for this purpose. The ultrasonic radiation is sent towards the inside of the pipe, transversely to the flow of liquid. Each cell in each housing generates an internal fountain generated in the liquid.

In a preferred embodiment, a reservoir is provided with an inlet and an outlet, the reservoir having planar faces provided with openings capable of receiving the housing or housings according to the invention (for example according to the embodiment of FIG. 8). The reservoir is preferably longitudinal but of any orientation. A prismatic tank of pentagonal section can be provided with several boxes, for example 5 boxes, positioned longitudinally on each face, for example in a spiral. The arrangement of the boxes is such that the cells cannot be reached by radiation from other cells or by reflected radiation.

The housing according to the invention can, in certain embodiments, take general forms other than cylindrical. They can thus also be parallelepipedic, of square or polygonal section. The invention will be better understood on reading the following description, of specific examples of embodiment, with reference to the appended schematic drawings in which:

fig. 1 shows the two elements capable of forming, with the housings, a complete humidifier according to

1 invention fig. 2 shows front views A, in plan from above B and from side C of the humidifier according to FIG. 1 fig. 3 shows a sectional view before A and from above

B of an assembled humidifier fig. 4 shows more precisely in section and from above a first embodiment of a housing according to the invention FIG. 5 is an exploded perspective view in section of the various elements of the housing according to FIG. 4 fig. 6 shows in section and from above a housing according to another embodiment of FIG. 7 is an exploded view of the various elements of the housing according to FIG. 6 fig. 8 shows in section a housing according to a third embodiment. fig. 9 very schematically represents a compartment inserted in a water circuit and comprising on these side walls openings provided with housings according to

1 invention.

Identical reference numbers refer to identical elements or of equivalent functionality.

Fig. 1 very schematically represents the water tank 15 comprising the circular openings 11 suitable for receiving the boxes 2. It is noted that the bottom is inclined. The enclosure 16 receives the reservoir 15 and comprises at its bottom electrical contacts 17, 18 intended to supply the boxes and their generators.

The outer edges 19 of the tank 11 and the double bottom 20 fit exactly without space to allow the connection of accessories in a known manner, such as level controls, without entering the Faraday cage.

The electrical contacts between the generators placed in the boxes 2 and the electrical supply common to the tank generators are ensured by a circular spring 17 for one phase and a central spring 18 for the other phase, placed under each box so that 'by screwing the housing, the connection between the power supply and the generator is ensured.

The network is protected by capacitive bulkhead filters 21 and a differential filter 22 which sufficiently reduce the propagation of electromagnetic radiation in the supply network to comply with the standards in force.

Referring to Figures 4 and 5, the cylindrical housing 2 is formed of a cover 20 and a lower cover 9. The cylinder is thus closed in its upper part by a cover 20 whose edges 20 'project towards the outside. This cover has an opening of ± 18 mm in diameter. Under this opening is housed the piezoelectric crystal 3 of ± 20 mm in diameter which vibrates at ± 1,700 KHz. It is placed in a rubber seal 5 perpendicular to the axis of the cylindrical housing. A plate 6 placed inside the tube is fixed from the inside to the cover. It clamps the seal 5 against the cover 20 which seals the seal. This metal plate also seals the housing against electromagnetic waves produced by the generator.

The generator (oscillator) 7 is fixed to this plate 6 as well as the transistor 8 which ensures the evacuation of the heat produced by it. By conductivity, the entire housing ensures the dispersion of heat.

The housing is housed in an opening 11 in the water tank. The outer edges 20 ′ of the cover rest on a seal 4 placed under this edge

A quick fixing system ensures tight tightening of the case against the interior wall of the water tank while determining the direction and therefore the inclination of the crystal.

For example, the housing is screwed to the tank. The opening 11 and the outer surface of the housing are provided with a net. The inner edge of the cover 13 is provided with notches in which will be placed a tightening tool provided with suitable protrusions. These notches may also be located on the upper face of the housing in contact with the liquid to be sprayed. According to a variant, this fixing system could also be of the bayonet type. We can also fix the box using screws accessible from the tank and passing through the outer edge 20 'of the cover and in the joint 4 (not shown).

A cover 9 fixed to the lower part of the tube 20, for example also by screwing (not shown) is adapted to allow the passage, sealed to electromagnetic radiation, of the power supply 10. The latter 'is filtered using a differential filter and capacitive bulkhead filters which reduce the propagation of electromagnetic radiation in the supply network to comply with current standards.

According to another aspect of the invention, the cover is pierced at its center. It is integrated into the cylinder. Its internal diameter is defined by the size of the generator. The plate 6 is fixed to the inner rim of the cover using screws 14 screwed from the inside. The generator 7 is fixed using these same screws. One of the screws is also used to fix the transistor. A material that is good conductor of heat and resistant to corrosion to water and to demineralized water, such as for example aluminum or one of its alloys, will be used.

According to a particularly advantageous variant, the bottom of the tank is inclined by ± 7 ° in order to give the necessary angle to the crystal. It should no longer be oriented using an inclined joint placed in a precise position with nuts or a bayonet system. Lips 12 in depression at the edge of the opening 11 allow the seal 4 to be supported. The height of this depression corresponds to the cumulative height of the thickness of the outer edge of the housing and of the seal.

The reservoir 15 is preferably advantageously made of a material which is good conductor of electromagnetic radiation and resistant to corrosion with water and demineralized water such as for example aluminum or one of its alloys or a plastic composite.

According to a variant, the cover 9 fixed to the lower part of the tube can be replaced by a double metal bottom of the reservoir 16 encompassing all the housings while constituting a Faraday cage impervious to electromagnetic radiation.

According to another variant illustrated in Figures 6 and 7, the plate 6, the generator 7 and the cover 9 are fixed inside the housing via a circlip 28. The bulkhead filters 21 and the power supply 10 are fixed on the cover 9. The seal 4 is located on the outside diameter of the housing in a groove 24. It will be noted the presence of an annular element 29 to space the plate 9 of the generator 7. The notches 23, in the form of a head slot screws, are located on the exposed upper side of the housing.

For this embodiment, the replacement of the housing supposes the prior disconnection, in a conventional manner, of the electrical supply (eg male and female plugs). This disconnection is easily done manually, after having lifted and disconnected the reservoir 15 from the enclosure 16. Alternatively, if rigid plugs are provided, decoupling leads to disconnection.

According to yet another variant illustrated in FIG. 8, the crystal 3, its seal 5, the plate 6 and the generator 7 are mounted in a cylinder 25 which fits into the element 20 fixed or integrated at the bottom of the tank (by welding or provided in one piece by molding) thus making 0 opening office 11. A groove 26 allows the placement of a 0-ring 27 ensuring sealing between the cylinder and the cover 20. A plug 25 is screwed (thread 31, 31 ') on the the outside of the cover or element 20, fixed or integral with the tank as described above, thus ensuring tightening between the cylinder 24 and the cover 20.

According to the latter embodiment, the housing can be replaced from below the tank and no longer from above. 0

The tank can also in this case be closed or be in series with a water pipe as illustrated in fig. 9. Element 20 will no longer be part of the bottom of a humidifier tank but, for example, of a wall of a compartment (or of a pipe section) intended for water treatment, for example water purification from an open or semi-open circuit.

0

Claims

claims

1. Ultrasonic humidifier in which at least one pair of cell and associated generator is incorporated in a removable housing to be inserted in an opening or recess in the bottom of the water tank, the housing comprising an opening capable of exposing a piezoelectric cell.

2. Humidifier according to the preceding claim wherein the lower part of the housing comprises connection means for the power supply.

3. Ultrasonic humidifier in which the removable housing comprises at its upper part means for fixing to the bottom of the tank.

4. Humidifier according to claims 1 or 2 wherein the upper part of one or more housings has edges projecting outwardly and pressing on part of the bottom of the tank by means of seals, the said upper part comprising an opening in which the piezoelectric crystal is housed.

5. Humidifier according to any one of the preceding claims, in which at least one housing is in the form of a threaded cylinder on its external surface, the net being complementary to a net provided in a recess or an opening in the bottom of the tank. .

6. Humidifier according to any one of the preceding claims, in which the upper part of the cylinder is provided with notches accessible by a tightening-loosening tool.

7. Humidifier according to any one of the preceding claims, in which the bottom of the tank is inclined by +/- 7 °.

8. Humidifier according to any one of the preceding claims, in which each box is powered by electrical contacts located under said box and secured to the bottom of an external enclosure receiving the tank.

9. Humidifier according to any one of the preceding claims, in which the cell-generator assembly is fixed in the housing by a fixing system located inside said housing.

10. Humidifier according to any one of the preceding claims, in which each housing consists of an upper cover comprising a central opening, and of a lower cover.

11. Humidifier according to any one of the preceding claims, in which the housing comprises a metal plate (6) inside one or the cover.

(20) tightening a seal (5), carrying the piezoelectric cell (3), against an upper internal face part of the cover.

12. Humidifier according to the preceding claim wherein the generator and the transistor are fixed to the plate (6).

i 13. Humidifier according to any one of the preceding claims, in which the housing also comprises a cover (9) fixed at its lower part, impermeable to electromagnetic radiation and adapted to ensure the passage of the electrical supply.

14. Humidifier according to the preceding claim wherein the cover is associated with a differential filter and / or a capacitive bulkhead filter.

15. Humidifier according to any one of the preceding claims, in which the cell and the generator are fixed in a cylinder which fits into the housing.

16. Removable housing, for humidifier or, in which the upper part has edges projecting outwards and pressing on a part of the bottom of the tank via seals, said upper part comprising an opening in which is housed the piezoelectric crystal and the lower part of the housing comprising connection means for the power supply.

17. Removable housing for a water treatment device comprising a piezoelectric cell, a generator and a transistor, capable of being fixed by screwing or pressure in or on an opening of a wall of a tank, a compartment, a pipe or a water circuit, said box having the characteristics of the boxes of claims 1 to 15.