BRPI0609775A2 - device and process for treating a flux by light radiation - Google Patents

Abstract

DEVICE AND PROCESS FOR THE TREATMENT OF A FLOW BY A LIGHTING RADIATION. The present invention relates to a device for the treatment of a flux by a luminous radiation, the device comprising microwave generating means (10a, 10b, 10c), at least one microwave cavity (20) comprising microwave-tight walls to confine the microwaves, at least one irradiation channel (30) in which the flow to be treated, at least one enclosure (40) containing a plasma, located inside the microwave cavity, means for generating a magnetic field (50 ), enclosure (s), cavity (s), and means of generating the magnetic field and microwaves being arranged in such a way as to generate a cyclotronic electron resonance within the enclosure (s) to emit a light radiation that allows the irradiation of fluid to be treated, notable for the fact that the means of generating the magnetic field are constituted by at least one permanent magnet and by the fact that each enclosure is arranged in the immediate proximity of at least one magnet.

Description

"DEVICE AND PROCESS FOR TREATING A FLOW BY LIGHT RADIATION"

The invention relates to the general technical field of light radiation flux treatment.

More particularly, the invention relates to the technical field of treating a gas, liquid, or solid with the aid of infrared, visible or ultraviolet light radiation emitted by a microwave excited device and generating a Cyclotron Resonance of Electrons (CERs).

The invention finds advantageously, but not limited to, application in the field of water and air sterilization.

PREVIOUS ART OVERVIEW

Devices have already been proposed for treating a flux by light radiation.

Among such devices, devices are known which comprise one or more high or low voltage mercury low or medium pressure lamps positioned within a reservoir which allows a flow to flow.

However, these devices have numerous drawbacks notably in terms of volume, life span, difficulty of ignition and non-modulating power of medium and low pressure lamps.

To remedy the drawbacks of such devices, microwave excited devices have been proposed.

These devices include:

a cavity for microwave confinement that allows flow in and out,

microwave generating means comprising a microwave generator and means for bringing microwaves from the generator to the cavity,

-a channel of irradiation in which the flow to radiate circulates,

at least one enclosure, positioned within the cavity, which contains a plasma intended to be excited by microwaves in order to emit light radiation.

These devices have specific geometries and arrangements depending on the substance to be irradiated and the desired mode of irradiation.

W09837962 and W09953524 define a rectangular microwave cavity, a tubular irradiation channel, an annular enclosure positioned within the microwave cavity around the irradiation channel of a gas or liquid stream.

JP611046290 and JP1 1985454 define a rectangular cavity, an irradiation channel confused with the microwave cavity and serving as a water reservoir. The plasma enclosure is inside the microwave cavity, immersed in the water to be treated.

FR2674526 and US3911318 describe a tubular microwave cavity, a tubular irradiation channel, and an annular enclosure positioned within the microwave cavity around the irradiation channel of an optical fiber or fluid.

US5931557 defines a rectangular cavity and various geometries of irradiation channels associated with plasma enclosures intended to radiate an air flow.

US6559460, designed on a more complex microwave cavity geometry, adds light reflecting means to improve irradiation uniformity of a substrate stream.

However, these devices induce operative restrictions: in the size and shape of the microwave cavity (cf. W09837962, JPl 1046290, JPl 198545, US3911318, US5931557), the minimum microwave power to be supplied (cf. W09837962, JP61198545, FR2674526, US5931557, US6559460), in positioning the plasma enclosure (s) within the microwave cavity (cf. US5931557 and US6559460) which make such devices complex to perform.

These multiple conditions taught to the practitioner to execute a microwave excited device for treating a flow do not allow him to provide a compact device.

In addition, the restrictions imposed in these documents on the size and shape of microwave cavities, and on the placement of enclosures within the cavity, prevent optimal flow irradiation. In addition, these devices have limited effectiveness and brightness.

"Brightness" within the scope of the present invention is the radiation density per surface unit.

"Effectiveness" means, within the scope of the present invention, a performance which corresponds to the ratio of the light energy generated by the device to its microwave power supplied to the device.

Finally, these devices work very poorly with low power (less than 200 Watts).

To correct the low brightness drawbacks of microwaved priced devices, devices using the CER phenomenon have been proposed.

The CER is known for improving the energy level of microwave excited plasmas.

It consists in introducing a magnetic field which, as a function of the frequency of the microwave wave and the value of the magnetic field, causes a cyclotronic resonance of the plasma electrons within the enclosure of a very low pressure plasma.

This phenomenon improves the radiance brightness of the room.

US 3,911,318 describes a microwave device for treating a material stream by light irradiation.

The device comprises Helmholtz coils for generating a magnetic field to obtain a CER within an annular plasma enclosure surrounding a tubular irradiation circuit.

This device enhances the room's brightness but has the following drawbacks:

this device is bulky due to the use of Helmholtz coils,

This device is not very compact as the microwave cavity is of multiple wavelength volume (useless volume between the microwave cavity and the plasma enclosure) to allow maximum electromagnetic field zones to be obtained, this device does not protect the channel from microwave irradiation, which is especially harmful in the case of a liquid treatment,

This device does not have all the safety conditions necessary to treat a flow and more especially a liquid:

In particular, the device has microwave leaks at the inlet and outlet level of the flow to be treated,

o The use of the device described in US 3 911 318 is hazardous if the flux to be radiated is water as the use of Helmholtz coils requires the application of large currents to allow the generation of a magnetic field sufficiently powerful for a Cyclotronic Resonance.

of electrons is obtained.

An object of the invention is to propose a microwave flow treatment device (liquid, gas or solid) which has all the necessary safety and at the same time combines compactness, brightness and efficiency, low power operation and optionally protects the fluid. microwaves if necessary.

PRESENTATION OF THE INVENTION

For this purpose, a device for treating a flux by light radiation is provided, the device comprising: microwave generating means,

at least one microwave cavity comprising microwave-tight walls for confining the microwaves, at least one irradiation channel in which the flow to be treated circulates,

- at least one plasma-enclosed enclosure within the microwave cavity,

means of generating a magnetic field,

enclosure (s), cavity (s), and magnetic field and microwave generating means being arranged to generate a cyclotronic resonance of electrons within the enclosure (s) to emit a light radiation permitting irradiation of the fluid to be treated, wherein the magnetic field generating means is comprised of at least one permanent magnet and each enclosure is disposed in the immediate vicinity of at least one magnet.

"Flowing" within the scope of the present invention means a gas, a liquid, or a moving solid, that is more especially circulating in the channel.

"Immediate proximity" within the scope of the present invention means a distance D between the enclosure and the permanent magnet less than or equal to a dimension L of the magnet along a magnet (parallel to the magnet magnet vector) magnet magnet, preferably less than or equal to L / 2.

Preferred but not limiting aspects of the device according to the invention are as follows: each cavity is inscribed in one volume, at least one of the characteristic dimensions (height, length, width) of the smallest volume to which the microwave cavity is inscribed. at 25 centimeters,

the device comprises means for monitoring, at reference light intensity, microwave power, and / or gas pressure and / or temperature of the device, the device comprises means for modulating microwave power within the enclosure, such means of power modulation generating pulses, each cavity is associated with a unique antenna.

In one embodiment, the permanent magnet (s) are arranged within the microwave cavity (s).

According to a first variant of this embodiment, the channel (s) is (are) disposed within the cavity (s). Optionally, the walls forming the cavity (s) and the walls forming the channel (s) may be confused, and the device may comprise a plurality of enclosures and a plurality of permanent magnets.

According to a second variant of this embodiment, the device comprises one (or several) cavity (s) arranged to encompass the channel (s), the walls of the cavity (s) (s). in front of the channel (s) being transparent to the light radiation. On the other hand, the channel (s) is (or are) tubular in shape, and the cavity (s) is (or are) annular in shape.

The second variant of the embodiment may either comprise a single annular enclosure or comprise a plurality of enclosures around the channel. Optionally in the device according to the invention either: each room is associated with a permanent magnet of its own, or

each magnet is associated with a plurality of enclosures, or

Each room is associated with a plurality of permanent magnets.

In all cases, the device may comprise light radiation reflecting means arranged to direct the light radiation in the direction of the flux to be treated.

On the other hand, in all cases, the outer wall (s) of the cavity (s) may be opaque to light radiation.

In addition, in all cases the microwave generating means comprises either:

a microwave power generator and a waveguide, the waveguide being arranged between the generator and the cavity to guide the microwaves generated by the generator towards the cavity, or a microwave power generator, at least one coaxial cable, and at least one antenna, the cable (s) being arranged between the generator and the cavity, the antenna (s) being arranged within the cavity (s) ( s).

The invention also relates to a process for treating a flux by a light radiation using for this purpose a device according to one of the preceding two claims, the light radiation having a predetermined light spectrum and intensity, characterized in that that the process comprises a spectrum control step as a function of the average temporal microwave power within the enclosure and the maximum microwave power within the enclosure.

FIGURE PRESENTATION

Further features, objects and advantages of the present invention will be further noted from the following description, which description is purely illustrative and not limiting and should be read with reference to the accompanying drawings in which: Figures 1, 2, 6, 7, 9 and 11 are longitudinal sectional views of different embodiments of the device according to the invention;

Figures 3, 4, 5, 8, 10 and 12 are cross-sectional views of different embodiments of the device according to the invention;

13 schematically illustrates a special embodiment of an assembly comprising four devices according to the invention;

Figure 14 represents, as a function of time, three special embodiments of the microwave energy supplying the device according to the invention.

DESCRIPTION OF THE INVENTION

The device for the treatment of a light radiation flux according to the invention will now be described with reference to figures 1 to 14.

Referring to Figure 1, the device according to the invention comprises:

- microwave generating means 10a, 10b, 10c,

- at least one microwave cavity 20 for confining the microwaves,

- at least one irradiation channel 30 in which the flow to be treated circulates,

- at least one plasma enclosure 40 located within the microwave cavity, and

- means for generating a magnetic field 50.

Microwave generating means 10a, 10b, 10c comprise a microwave power generator 10a and means for bringing microwaves 10b, 10c into cavity 20. Microwave power generator 10a and microwave guide means 10b, Cavity 20 may be all means known to the practitioner to perform these functions.

The IOa microwave power generator is for example an electron tube, transistor, or magnetron type.

Means for bringing microwaves 10b, 10c into cavity 20 are for example:

one or more waveguide (s),

one (or several) coaxial cable (s) 10b and one (or several) antenna (s) 10c.

"Microwave" means electromagnetic waves of frequencies exceeding 1 GHz, preferably below 30 GHz, more preferably between 1,8 GHz and 6,4 GHz.

The microwave power generators of standard microwave ovens allow the generation of magnetic waves of a frequency of 2.45 GHz. These microwave power generators being very widespread, it will advantageously be possible to use microwave power generators that allow the generation of magnetic waves with a frequency of 2.45 GHz.

Microwave cavity 20 is a Faraday box. The microwave cavity 20 is designed to confine the microwaves within to protect the external environment against the electromagnetic fields produced within the cavity 20. To this end, the cavity 20 comprises microwave opaque walls. The cavity may comprise light transparent walls, and more especially the cavity walls directly in front of the channel in which the flow to be treated circulates. The light transparent, microwave opaque walls may be an electrically conductive screen 23 or 24. A Microwave cavity 20 has any shape and size. More particularly, the shape and dimensions of cavity 20 are independent of microwave frequency.

Irradiation channel 30 is a volume of any shape and size and variable along channel 30. Channel 30 comprises a flow inlet 30a and a flowout 30b. The irradiation channel 30 allows the circulation of the flow to radiate, the direction of flow circulation being given by the referenced arrow SCF in the accompanying drawings. The irradiation channel is made of a material transparent to light radiation, preferably made of quartz or glass. In certain embodiments, the channel is a removable tube. Thus, in the case of a water flow, instead of withdrawing the tartar from a solidarity channel of the device, the tube can simply be replaced with a clean tube. The removal of tartar can also be done thanks to a broom.

Plasma enclosure 40 is a watertight enclosure for the confinement of any low pressure gas. This room 40 has any shape and dimension. The walls of room 40 are microwave transparent. Enclosure 40 comprises at least one wall transparent to radiation emitted by the plasma. This transparent wall is the wall in front of the channel in which the flow to be treated circulates. The other enclosure wall may optionally be opaque to light radiation, and preferably comprise a reflective coating to reflect light radiation towards the channel.

"Low pressure" means within the scope of the present invention a pressure of 10 4 to 10 millibars.

The means for generating a magnetic field 50 are means for generating a magnetic field.

Enclosure 40 (or enclosures), cavity (s) 20, and magnetic field and microwave generating means 10a, 10b, 10c, 50 are arranged to generate an Electron Cyclotronic Resonance ( hereinafter referred to as the CER) within the enclosure (or enclosures) to emit a light radiation which allows the irradiation of

WHR, or Gyromagnetic Resonance is a technique of activating a plasma. The principle of plasma activation consists of superimposing a frequency electromagnetic wave given a static magnetic field such that the rotating frequency of the electrons in the magnetic field is equal to the frequency of the exciting electromagnetic wave.

When the resonance phenomenon occurs, the plasma electrons gain energy and collision ionize the plasma: light radiation is then generated.

The phenomenon of WHtR enhances the brightness and effectiveness of the room's radiation.

A first feature of the device according to the invention relates to the fact that the magnetic field generation means 50 are comprised of at least one permanent magnet.

This permanent magnet 50 has any shape. The dimensions of permanent magnet 50 are chosen as small as possible to obtain the CER within the enclosure. The professional knows how to determine the minimum dimensions of the magnet that allow obtaining a CER within the enclosure.

Whatever the shape of permanent magnet 50, the latter has a privileged magnetization axis parallel to the magnet magnetization vector.

Permanent magnet 50 may be comprised of a single magnet or a plurality of contiguous elementary permanent magnets.

A second feature of the device according to the invention relates to the fact that the magnetic field generating means 50 are arranged in the vicinity of at least one enclosure 40.

"Immediate proximity" within the scope of the present invention means a distance D between enclosure 40 and permanent magnet 50 less than or equal to the dimension L of magnet 50 along the preferred magnetization axis of magnet 50, preferably less than or equal to equal to L / 2.

Even more preferably, the permanent magnet 50 is in contact with the enclosure wall 40 - in other words the distance D between the enclosure 40 and the magnet 50 is nil - possibly with a reflector wall 60 or cavity 20 between the enclosure. permanent magnet 50 and enclosure 40.

The fact that the magnetic field generating means 50 consists of one or more magnets 50 arranged in close proximity to one or more enclosures 40 allows:

- improve the brightness and radiation efficiency of enclosures 40 by designing devices with fully microwave-tight cavities 20 of any size not necessarily multiple wavelengths of microwaves and compactly, which may eventually protect the microwave irradiation channel. ,

have immediate ignition operation at very low power (some watts) when the cavity is larger than 1A wavelength,

create radiance zones 80 for CERs that can be freely and precisely positioned to optimize the effectiveness of the irradiation with respect to the flow to be treated.

The description of the elements of the device according to the invention made above with reference to figure 1 also applies to the other embodiments illustrated in figures 2 to 14.

In the embodiment illustrated in Figure 1, enclosure 40 is annular in shape and comprises for example a mercury plasma for emitting a bactericidal 254 nm wavelength radiation.

The enclosure 40 is disposed around the irradiation channel 30 which has a tubular shape. The enclosure 40 is disposed within the microwave cavity 20 which is also annular in shape and encompasses the irradiation channel 30.

An application of the embodiment illustrated in Figure 1 may be the treatment of small water flows by light radiation of wavelength of 254 nm.

This device actually lets you emit light radiation over a water flow of a few m3 / h that passes through a standard (3/4 inch) pipe. The channel 30 is preferably tubular and transparent to light radiation on its entire surface to allow very effective irradiation, under 4pi, of the flux in order to eliminate bacteria therefrom for example.

Microwave generating means 10a, 10b, 10c comprise a microwave power generator 10a connected to one (or more) coaxial cable (s) 10b and one (or several) antenna (10c) for bringing the microwaves generated by the generator into the cavity.

A coaxial cable - which has the peculiarity of being flexible - associated with an antenna is easier to have than a waveguide - which is rigid and bulky (in fact, at least one of the characteristic dimensions of the guide is generally larger than one. half the wavelength of microwaves).

On the other hand, the effectiveness of a waveguide in bringing microwaves into the cavity depends on their shape and dimensions. In contrast, the combination of an antenna and a coaxial cable to carry microwaves into the cavity has no shape constraints.

As a result, the use of an IOb coaxial cable coupled with an antenna 10c for microwave entry into the cavity 20 allows for greater flexibility in carrying out the device according to the invention. However, the device according to the invention may also be executed with a waveguide. The antenna 10c is preferably arranged entirely within the microwave opaque cavity 20.

Thus, the channel and the external environment are completely protected from possible microwave irradiation.

Microwave irradiation of channel 20 may cause interactions between the flow to be treated and the microwaves.

In particular, the interaction of microwaves with a non-zero dipolar moment liquid such as water may result in:

an increase in liquid temperature by microwave absorption,

a decrease in the effectiveness of room 40 radiation due to the absorption of microwaves by the liquid to be treated.

On the other hand, in the case of water sterilization, the increase in water temperature by microwave irradiation has the disadvantage of favoring water contamination.

Radiation from the outside environment by microwaves can cause serious injury to users near the device (chromosome alteration, etc.).

In the device illustrated in Figure 1, these drawbacks are alleviated by the presence of the annular cavity 20 and fully enclosed and thus opaque to microwaves and by the arrangement of the 10c antenna within that cavity 20.

The different elements of the device according to the invention are arranged to cause a CER within the enclosure. This allows instant ignition, for example in a millisecond. This allows multiple applications of the device according to the invention and in particular the treatment of non-continuous flow, such as sterilization of water on demand, where the device should in principle only be lit when a water tap is opened. In the embodiment illustrated in Figure 1, the permanent magnets 50 are disposed within the cavity 20 and are in contact with the outer wall of the enclosure 40.

The magnets 50 are distributed around the enclosure 40 to homogenize the radiation of the resonance zones 80 in the irradiation channel 30.

While the proximal walls 41 (relative to channel 30) of enclosure 40 disposed in front of channel 30 must be transparent to light radiation, the distal walls 42 (relative to channel 30) of enclosure 40 may be opaque to radiation. preferably reflective to reflect light radiation in the direction of the channel in which the flow circulates.

The cavity comprises proximal walls 21 relative to channel 30 transparent to light radiation. However, distal walls 22 relative to channel 30 of cavity 20 may be opaque to light radiation. This is especially the case when the plasma contained within enclosure 40 is mercury that emits light radiation in the UV domain that should not come out of the cavity for safety reasons in order not to radiate users near the device.

The device illustrated in Figure 1 further comprises light radiation reflecting means 60 arranged to direct the light radiation in the direction of the flux to be treated.

These light radiation reflecting means 60 allow the light radiation to be concentrated towards the channel 30 in which the flow to be treated circulates in order to increase the effectiveness of the treatment.

In the embodiment illustrated in Figure 1, the light radiation reflecting means 60 is a reflective coating layer placed on the outer face of the enclosure wall 40 and arranged to reflect the light radiation towards the channel 30.

More particularly, the reflective coating layer is placed over the outer face portion of the enclosure 40 which is furthest from the channel 30 in which the flow circulates.

The device illustrated in Figure 1 can for example be integrated into the screen of a common shower system that blocks UV outwards, or be combined into an extremely compact system that includes a prefilter and an anti-tartar system.

Referring to Figure 2, another embodiment of the device according to the invention is adapted for treating a liquid such as water for flow rates between 10 and 100 m3 / h.

This embodiment differs from the embodiment illustrated in Figure 1 in that, in this embodiment, magnets 50 are disposed outside cavity 20 but in contact with cavity 20, and enclosure 40 occupies almost all of the housing. cavity volume (namely the volume of the cavity minus the volume required to arrange the antenna 10c).

With such a device, the volume of the channel directly in front of the enclosure is maximized to maximize water passage time within the enclosure, while minimizing cavity dimensions 20.

This allows optimizing the compactness of the device according to the invention.

The permanent magnets of the device illustrated in Figure 2 are disposed outside the microwave cavity and in contact with the cavity wall 20 to be in close proximity to the enclosure 40. This allows the use of cavities of non-multiple wavelength dimensions. microwaves with a diameter of less than 24.4 centimeters, which is twice the wavelength of microwaves at a frequency of 2.45 GHz.

Thus, preferably each cavity 20 is inscribed in a volume at least one of the characteristic dimensions (height, length, width) of the smallest volume to which the microwave cavity 20 is inscribed being less than about 25 centimeters (more precisely 24 , 4 centimeters), which corresponds to twice the microwave wavelength at the frequency of 2.45 GHz.

The practitioner will appreciate that for higher frequencies, for example a frequency of 5 GHz, at least one of the characteristic dimensions of the smallest volume in which the cavity is inserted will preferably be less than 12 centimeters. Similarly, for lower frequencies, for example a frequency of 1 GHz, at least one of the characteristic dimensions of the smallest volume to which the cavity is inserted will preferably be less than about 48 centimeters.

Of course, it is also possible to use a microwave energy generator 10a which generates microwaves at the frequency of 1 GHz or GHz with a device of which one of the characteristic dimensions of the smallest volume to which the cavity is inserted is less than 25 cm.

The magnets are distributed around the enclosure to homogenize the radiation of the resonance zones in the irradiation channel.

Referring to FIG. 3, the cross-sectional view illustrates the embodiment illustrated in FIG. 1 which allows a better appreciation of the special arrangement of permanent magnets 50 within cavity 20.

Four permanent magnets are arranged around annular enclosure 40 located within cavity 20. Magnets 50 are arranged symmetrically with respect to the axis of channel 30, and in close proximity to the enclosure wall 40.

Enclosure 40 and cavity 20 surround a tubular channel.

An antenna 10c is disposed within cavity 20 for microwave generation.

Permanent magnets 50 generate field lines that permit resonance zones 80 to be obtained around channel 30 in which the flow to be treated circulates.

The wall of the enclosure 40 which is furthest from channel 30 comprises a reflective coating which allows light to reflect light R towards channel 30. For example, the furthest channel wall is made of aluminum to be microwave opaque and to reflect the light radiation.

The proximal wall 21 of cavity 20 is an electrically conductive screen 23 to be microwave opaque and transparent to light radiation.

Alternatively, the proximal wall 21 made of mesh may be peeled off to be transparent to light radiation and microwaves, for example when the flux to be treated does not interact with (absorbing) the microwaves.

In such a case, the device may be combined with means external to the device to prevent radiation from users in the vicinity of the device. Such external means may for example be arranged along channel 30 at the inlet and outlet of the device according to the invention.

In the case of treating a low flow water stream, a device according to the variant described above may be used. However, the water interacting with the microwaves absorbing them, the effectiveness of the device is diminished, and the water is heated.

Referring to Figure 4, another embodiment of the device according to the invention has been illustrated.

This embodiment, as well as the embodiment illustrated in figure 5, is especially adapted to the treatment of liquid such as water for flows between 100 and 1000 m3 / h. In this embodiment, permanent magnets 50 are disposed within cavity 20. This is made possible by the use of permanent magnets as magnetic field generating means in place of Helmholtz coils which, unlike permanent magnets, cannot be disposed. inside cavity 20 because of incompatibility between coils and microwaves.

On the other hand, the use of permanent magnets 50 disposed within the cavity 20 allows to reduce the dimensions of the device to the dimensions of the cavity 20 and thus to improve the compactness of the device, while the use of Helmholtz coils necessarily placed outside the cavity. , generates an increase in the dimensions of the device, the dimensions of the coils adding to the dimensions of the cavity.

In the embodiment illustrated in figure 4, the device comprises a plurality of enclosures. These enclosures are associated with a plurality of permanent magnets.

The shape of the enclosures shown in figure 4 differs from that of the enclosures shown in figures 1 to 3. In fact, in the embodiment illustrated in figure 4, each enclosure 40 has a tubular shape.

The enclosures of the device illustrated in Figure 4 are arranged around the irradiation channel 30 along the latter. In other words, the axis of symmetry of revolution of the enclosures is parallel to the axis of symmetry of revolution of the channel (when the latter has a tubular shape).

In the embodiment illustrated in Figure 4, the light radiation reflecting means 60 is a reflective coating layer placed on the inner face of the outer wall of the cavity 20 and arranged to reflect the light radiation R towards the channel 30. More especially, the reflective coating layer is placed over the inner face portion of the cavity 20 other than that directly in front of the channel 30 in which the flow circulates, which may be a screen 23.

Referring to Figure 5, another embodiment of the device according to the invention has been illustrated.

In this embodiment, the device comprises a plurality of enclosures 40, cavities and antenna 10c, notably four of each in Figure 5, shown in section.

The cavities are arranged to surround the channel in which the flow to be treated circulates. Preferably, the walls in contact with two adjacent cavities are an electrically conductive screen 24 so as to be microwave opaque and transparent to light radiation.

Each cavity 20 comprises an associated enclosure 40 and an associated antenna 10c.

The enclosures 40 are arranged around the channel 30. The enclosures 40 are preferably cylindrical in tubular shape and are disposed along the tubular and cylindrical channel 30 itself.

In this embodiment, the light radiation reflecting means 60 are independent reflectors.

Each reflector 60 is associated with a cavity 20, and comprises a reflective surface disposed in front of the enclosure 40 and facing the channel 30 in which the flow circulates.

The device further comprises a plurality of permanent magnets. Each cavity 20 is associated with a magnet 50. Permanent magnets 50 are disposed outside the cavities, each magnet being in contact with the outer wall of its associated cavity 20 to be in close proximity to its associated enclosure.

Each magnet creates a magnetic field within the enclosure that is associated with it. Each antenna 10c emits microwaves in its associated cavity 20, and thus in its associated enclosure, which allows obtaining the phenomenon of CER. The fact that the device illustrated in figure 5 comprises a plurality of cavities allows to control the distribution of microwave power within each cavity, and thus homogenize the radiation in all enclosures to optimize flow irradiation.

In the embodiment illustrated in figure 6, the device according to the invention is used for sterilization of water. For such use, the device comprises quick clamping means 70 for connecting the irradiation channel to a flow distribution point 80, such as a water tap.

The quick clamping means 70 comprises screw or snap fastening means, and preferably comprises a flexible joint adaptable at the flow distribution point 80.

As shown in Figure 6, the microwave power generator 10a is disposed at a distance from cavity 20, and connected to the cavity by means of a coaxial cable 1 Ob and an antenna 1 Oc for microwave entry into cavity 20.

The device illustrated in figure 6 notably allows treating the last drop leaving the dispensing point 80.

Referring to Figures 7 and 8, another embodiment according to the invention has been illustrated.

Such an embodiment is for example adapted to the treatment of a gas. More specifically, such a device is for example adapted for the treatment of air by irradiation.

Such an embodiment allows for example to emit light radiation (for example at a wavelength of 254 nm) over an air stream to disentangle it from its bacteria.

In this embodiment, the walls of the irradiation channel 30 and cavity 20 are confused. In fact, there is no interaction between microwaves and air. The channel 20 has for example a cylindrical shape and any size.

The device comprises a single enclosure 40 associated with a single permanent magnet 50.

Enclosure 40 is disposed within cavity 20, and comprises for example a mercury plasma for emitting radiation at a bactericidal 254 nm wavelength.

Channel 30 inlet and outlet are closed by an electrically conductive screen to prevent microwave irradiation from outside the cavity 20.

The permanent magnet 50 is disposed within the cavity 20, which increases the compactness of the device.

The device comprises reflective means of light radiation 60 on the inner face of the outer wall of the cavity 20.

Referring to FIGS. 9 and 10, another embodiment has been illustrated which differs from the embodiment illustrated in FIGS. 7 and 8 in that in this embodiment, permanent magnet 50 is disposed within enclosure 40. This allows avoiding shady areas within the cavity, and thereby increasing the effectiveness of the treatment device according to the invention.

Referring to Figures 11 and 12 which are longitudinal and cross-sectional views, another embodiment of the device according to the invention has been illustrated.

An application of such an embodiment of the device according to the invention is for example photocatalysis treatment of the air, for example using a Ti02 (titanium dioxide) type catalyst which can be placed on the inner faces of the cavity. 20 or on another support.

Other types of catalyst known to the practitioner may be used.

Such embodiment of the device according to the invention differs from the embodiment illustrated in figures 7 to 10 in that it comprises a plurality of enclosures 40 and a plurality of magnets.

Each room is preferably tubular and contains for example a nitrogen plasma (to emit UV-A and UV-B radiation which optimizes the Ti02 catalysis phenomenon).

The arrangement (beam) and shape of the enclosures allow to maximize the surface radiation and contact between air, Ti02, and UV radiation.

The permanent magnets and enclosures are disposed within the cavity and the irradiation channel (the channel and cavity walls being confused in this embodiment).

Each permanent magnet 50 is associated with at least one enclosure 40. This further enhances the compactness of the device according to the invention.

In Fig. 13, an assembly comprising four devices D1, D2, D3, D4 according to the invention has been shown. It is thus possible to radiate the flux circulating in irradiation channels 30, 30 ', 30 "with different light radiations, ie with light radiations having different spectra or intensities.

A control unit 18 also allows modulating the power P of microwaves injected into the enclosure, for example in the form of pulses of any shape and frequency.

These pulses are preferably rectangular as shown in Figure 14. The three curves P1, P2, P3 correspond to the same average power Pmn, and thus to the same average light intensity. In fact, according to the PI curve, a continuous power is injected into the enclosure. The continuous power Pl is equal to the average power Pmn. The average power injected Pmn is preferably from 10 to 1000 Watts. Curve P2 represents rectangular pulses having a maximum power Pmax2, for example with a frequency of 50 Hz5 and having a cyclic relationship such that the average power Pmn injected into the room is the same as that of the curve PI. Curve P3 has a frequency twice as low as that of curve P2 (in the example 50 Hz) and a maximum power Pm3 of rectangular pulses twice that of curve P2.

Thus, the average power Pmn of curves PI, P2, P3 is effectively equal. However, the maximum powers of the PI, P2, P3 curves being different, the PI, P2, P3 curves correspond to different light spectra.

According to a method of using at least one device according to the invention having a predetermined light spectrum and intensity, the spectrum is controlled by the maximum microwave power within the enclosure and the intensity is controlled by the average power of the microwave inside the enclosure.

When several elemental devices are used as in the set shown in Figure 13, the spectra and intensities of the different devices D1, D2, D3, D4 may be controlled by means of the maximum power of the average temporal power of the microwaves injected into the enclosures corresponding to D1, D2, D3, D4 devices.

The device according to the invention provides radiation in the visible spectrum and in the UV spectrum, corresponding to emission streams of atoms and ions of the gas. The 254 nm radius of the nonionized mercury atom can be obtained with low maximum powers. A light of 254 nm wavelength has photobiological effects, in particular a germicidal effect.

When the injected microwave power is increased, it is also possible to obtain emission rays from ionized atoms having wavelengths below 200 nm, for example the ionized mercury rays once, which have wavelengths of 164.9 nm and 194.2 nm. Light of these wavelengths has photochemical effects and allows, for example, to generate hydroxyl free radicals by irradiation with a brightness of the order of 120 mJ / cm for a single given wavelength.

Thus, moving from a power modulation such as that represented by curve P2 in FIG. 14 to a power modulation like that illustrated by curve P3 in FIG. 14, it is possible to tilt from a spectrum dominated by lane 254 to a spectrum. which also has a strong emission at wavelengths below 200 nm. The choice of gas and pressure and / or temperature within the enclosure allows the spectrum of the device to be adapted to its use, notably the desired ultraviolet regime.

On the other hand, a 195 nm ultraviolet light known to generate ozone, while a 254 nm ultraviolet light can suppress ozone. Thus, it is possible to consider a fluidic system, for example an ozone disinfected water circuit, comprising a first device according to the invention for generating ozone and a second device according to the invention disposed downstream of the first device (of according to the flow direction SCF of the flow), to suppress ozone so that ozone does not leave the assembly. Only the portion of the array disposed between the two devices then comprises ozone without presenting a danger to the user.

A reader will appreciate that numerous modifications can be brought to the foregoing device without materially departing from the teachings herein.

For example, in embodiments, the enclosure containing plasma and cavity is disposed within the channel. On the other hand, the number of enclosures, cavities, channels, and / or permanent magnets may vary depending on the applications. Finally, in certain embodiments, the device may comprise permanent magnets disposed inside and outside the cavity in the immediate vicinity of at least one enclosure.

EXECUTION EXAMPLE

The example execution shown below refers to Figure 1.

In this example, the flow to be treated is water.

The device comprises an irradiation channel made of quartz (to be UV-transparent, tubular in shape, with a diameter of 20 mm and a length of 90 mm, ie a volume of 30 cubic centimeters for the channel).

The device also comprises an enclosure made of annular quartz 60 mm in diameter arranged in a metal cavity (e.g. made of aluminum on the distal walls 22 and electrically conductive screen on the proximal wall 21), also of annular shape. 90 mm external diameter and 110 mm in length, and permanent magnets within the cavity arranged crosswise in top view around and in contact with the enclosure (to meet the immediate proximity criterion).

For a flow rate of 4 liters / hour, the water remains about 450 ms within the irradiation channel.

For a microwave power of 30 Watts, the enclosure filled with a mercury plasma generates a radiation of about 10 Watts of UV at 254 nanometers.

This radiation reduces the number of bacteria by 10 000 000 (log 7) (eg E.coli bacteria).

The invention therefore enables a very compact system to be obtained since the total volume of the device, which corresponds to the volume of the cavity in this embodiment, is equal to 0.7 liters. Such a device may be placed at the end of a tap as illustrated in 6.

Claims (23)

1. Device for treating a flux by light radiation, the device comprising: - microwave generating means (10a, 10b, 10c), - at least one microwave cavity (20) comprising watertight walls microwaves to confine microwaves, - at least one irradiation channel (30) in which the flow to be treated circulates, - at least one room (40) containing a plasma within the microwave cavity, - generating means magnetic field (50), enclosure (s), cavity (s), and magnetic field and microwave generation means being arranged to generate a cyclotronic electron resonance within the enclosure (s) for emit a light radiation which allows the irradiation of the fluid to be treated, characterized in that the means for generating the magnetic field are made up of at least one permanent magnet and the fact that each room is arranged in close proximity that of at least one magnet. Device according to the preceding claim, characterized in that each cavity (20) is inscribed in a volume of at least one of the characteristic dimensions (height, length, width) of the smallest volume in which the microwave cavity is inscribed. (20) being less than 25 centimeters. Device according to one of the preceding claims, characterized in that the permanent magnet is disposed within the microwave cavity (20). Device according to one of the preceding claims, characterized in that the channel (30) is disposed within the cavity (20). Device according to the preceding claim, characterized in that the walls forming the cavity (20) and the walls forming the channel () 30) are confused. Device according to one of the preceding two claims, characterized in that the device comprises a plurality of enclosures (40) and a plurality of permanent magnets. Device according to one of Claims 1 to 3, characterized in that the device comprises one or more cavities (20) arranged to include the channel (30), the walls of the cavity (s) in front of the channel being transparent to the light radiation. Device according to the preceding claim, characterized in that the device comprises a cavity (20) comprising the channel (30). Device according to the preceding claim, characterized in that the channel (30) has a tubular shape and the cavity (20) has an annular shape. Device according to the preceding claim, characterized in that the device comprises a single annular enclosure (40). Device according to one of Claims 7 to 9, characterized in that the device comprises a plurality of enclosures (40) around the channel (30). Device according to one of the preceding claims, characterized in that each room (40) is associated with a permanent magnet of its own. Device according to one of Claims 1 to 11, characterized in that each magnet is associated with a plurality of enclosures (40). Device according to one of Claims 1 to 11, characterized in that each room (40) is associated with a plurality of permanent magnets. Device according to one of the preceding claims, characterized in that the device comprises light radiation reflecting means (60) arranged to direct the light radiation in the direction of the flux to be treated. Device according to one of the preceding claims, characterized in that the outer wall of the cavity (20) is opaque to light radiation. Device according to one of the preceding claims, characterized in that the microwave generating means comprise a microwave power generator (10a) and a waveguide, the waveguide being arranged between the generator and the cavity. to guide the microwaves generated by the generator toward the cavity. Device according to one of Claims 1 to 16, characterized in that the microwave generating means comprise a microwave power generator (10a), at least one coaxial cable (10b), and at least one antenna ( 10c), the cable (s) being arranged between the generator and the cavity, the antenna (s) being arranged within the cavity (s). Device according to one of the preceding claims, characterized in that each cavity (20) is associated with a single antenna (10c). Device according to one of the preceding claims, characterized in that the device comprises monitoring means (18) at a reference light intensity of microwave power and / or gas pressure and / or temperature. of the device. Device according to one of the preceding claims, characterized in that the device comprises means for modulating the microwave power within the enclosure. Device according to the preceding claim, characterized in that the power modulating means generates impulses. A process for treating a flux by a light radiation using a device according to either of the preceding two claims, the light radiation having a predetermined light spectrum and intensity, characterized in that the process comprises a Spectrum control step as a function of the average temporal microwave power within the enclosure and the maximum microwave power within the enclosure.