WO2023160811A1

WO2023160811A1 - Cold plasma generator and applications comprising same

Info

Publication number: WO2023160811A1
Application number: PCT/EP2022/054887
Authority: WO
Inventors: Thi Hong Lien LUONG
Original assignee: Luong Thi Hong Lien
Priority date: 2022-02-25
Filing date: 2022-02-25
Publication date: 2023-08-31

Abstract

The present invention relates to a fully customizable cold plasma generator system used to generate activated water (PAW), to disinfect and inhibit the proliferation of harmful microorganisms in water distribution and storage systems. In addition, the invention also relates to devices that integrate this system for domestic use or in agriculture, industry, medicine, etc. The apparatus of the present invention consists of a power supply unit (1) connected to a high voltage pulse generator system (2), a plasma generator (3) according to the principle of Dielectric Barrier Discharge (DBD) with a special structure to optimize the performance of the reactions between plasma and solution depending on the purpose of use and has the ability to change both shape and size to suit the available system.

Description

COLD PLASMA GENERATOR AND APPLICATIONS COMPRISING SAME

Application domain

The invention relates to a compact, portable system for generating plasma activated water (Plasma Activated Water - PAW) and/or for disinfecting sanitary distribution/evacuation. More specifically, the invention relates to a cold plasma generation system based on the principle of dielectric barrier discharge (DBD) combined with the specific exchange principle to excite a chain reaction between plasma gas and water. The reaction of this plasma in water creates active ingredients that are used in the following fields of application:

- to disinfect, purify water,

- to use in daily activities for bathing, washing or washing vegetables, food,

- to disinfect items that need to be disinfected, and cleaned to minimize the use of chemical cleaners that are harmful to the environment.

In addition, plasma activated water is also used in agriculture to stimulate plants growth.

Yet another field of application that the invention would like to answer is the maintenance of the pipes / distribution of water or drinks avoiding the proliferation of pathogenic microorganisms.

Known prio-arts

The principle of creating ozone by plasma and then aerating ozone in the water to disinfect and purifier the water has been used relatively commonly in water purification platforms, water production or at waste water treatment centers. Some prio art patents ware described methods and devices for water decontamination. But the common deficiency of those methods and devices is the low efficiency of water solutions decontamination, herewith energy consumption per unit of water purified is relatively high and system are complexe and costly.

Some recent studies show that plasma activated water (PAW) has many good effects. According to the 2018 scientific paper « Plasma activated water (PAW): Chemistry, physico-chemical properties, applications in food and agriculture », Trends in Food Science & Technology, Volume 77, July 2018, Pages 21-31, in addition to plasma activated water having high sterilization properties, it also has the property of stimulating the growth of sprout and grow plants faster thanks to the ingredients containing hydrogen peroxide, nitrite and nitrate ions, etc. Hydrogen peroxide can activate plant growth and development, reduce both pathogen virulence and disease symptoms, as well as inhibit rudimentary leaf growth by reducing clogging caused by abscisic acid (ABA). Nitrite and nitrate ions, in addition to stimulating growth, plant food (nitrogen fertilizer) also has a bactericidal effect in low pH environments.

The Plasma Activated Water (PAW) solution was produced by the reactions between the plasma gas and water, see Fig. 1. The reactions between plasma gas and water vapour at the gas/water interface and the diffusion of results in water create PAW. We can see 4 pricipals phenomena (from left to right of Fig. 1): sputtering direct plasma discharge, afterglow plasma diffusion, UV interaction and electrolysis. Composition of PAW depend on phenomenum mainly occurred so depend on plasma generator principe and design. But UV interaction lacks of efficiency.

With very sort life time of primary components (OH*, H+, O*, N*, NO*, . . .) and secondary components (H2O2, NOX, 03, HNO2, HNO3, ...) of plasma gas, the closer plasma discharge chamber to water interface the better. The article in Journal of Physics and Applied Physics, October 2012 “Plasma chemistry model of surface microdischarge in humid air and dynamics of reactive neutral species” show that the distance between discharge chamber and treated surface should be less than 10mm, better between 0, 1mm to 1mm.

The application of Plasma Activated Water generation technology in daily life has not yet been widely popularized and can be further optimized both in terms of efficiency and safety, simplicity, low cost, easy to install and maintenance in existing equipment. Summary of the invention

The purpose of the present invention is to propose a cold plasma generator system arranged to activate liquid in order to disinfect and/or inhibit the proliferation of harmful microorganisms, the system comprising: a high voltage pulse generator supplied by a low power supply unit, a plasma generator comprising at least one active electrode, a dielectric layer, and a passive electrode.

The system is arranged to generate plasma gas according to the principle of Dielectric Barrier Discharge.

According to the invention, the at least one active electrode is formed by at least one electrical wire surrounded by a dielectric layer.

The advantages of the present invention are to propose a compact and/or autonomous cold plasma generating system that can be used to activate an effective aqueous solution, fully customizable, since it is possible to form or deform the electrical wire so as to form a shapable electrode, safe and easy to use by everybody to serve differents purposes:

- to provide clean water for daily activities,

- to ensure the supply of well-sterilized water for health pupose,

- to prevent the proliferation of microorganisms inside the pipes / distribution of water or drinks.

In addition, wire-shaped active electrode allows plasma to be emitted in all directions, and/or to have a greater plasma density than the surface plates of the prior art. This electrode can maximize contact surface of an appliance, for example in a nozzle. This type of Electrode is easily shaped.

Preferably, the dielectric layer or dielectric barrier covers the wire all around and in one mono-bloc. Preferably, between the dielectric and the electrical wire there is no gap and/or no junction and/or no welding or brazing or soldering.

Preferably, the high voltage pulse generator comprises at least one output, and the at least one output is connected to at least one pair of two ends of an electrical wire. According to one embodiment, the two ends of the at least one electrical wire are connected to one, preferably only one, output of the high voltage pulse generator. According to one embodiment, each pair of ends of one wire is connected to one output of the high voltage pulse generator. According to one embodiment, a plurality of pairs are conected to one output of the high voltage pulse generator.

Preferably, the at least one electrical wire has at least one curvature. For example, the wire is not straight. According to one embodiment, the at least one electrical wire has at least two curvatures so as to form a two or three dimension electrode.

Preferably, the at least one electrical wire has at least one curvature so as form two portions which are substantially parallel or have a substantially parallel trajectory.

According to one embodiment, the at least one active electrode is wounded in form of spiral having a plurality of portions, or turns, or whorls, wounded radially. Each portion is distanced or offset from its adjacent portion by a predetermined distance/gap different from zero. Preferably, all portions extend in one geometric plan.

According to another embodiment, the at least one active electrode is wounded in form of spiral having a plurality of portions wounded axially. Each portion being distanced or offset from its adjacent portion by a predetermined distance /gap different from zero. For example, the active electrode has a tube shape, which can present any shape like circular or conical shape.

According to a variant embodiment, the at least one active electrode is wounded in form of spiral having a plurality of portions wounded axially and radially.

According to another embodiment, the at least one active electrode being folded in a form of zigzag having a plurality of portions. Each portion is distanced/offset from its adjacent portion by a predetermined distance/gap different from zero. For example, all portions extend in one geometric plan. According to another example, the zigzag electrode is curved so as to form a tube.

According to yet another embodiment, the at least one active electrode has portions which are braided so as to form a braided layer.

Preferably, the passive electrode is formed by an electrical wire, preferably a bare wire, having passive portions and the active electrode having active portions, active portions being braided with passive portions so as to form a braided layer composed of active wires and passive wires.

Braided layer promotes the phenomenon of Afterglow.

According to any embodiments, the distance between two portions measured to at least one point of a portion can be between 0 to 4 times the optimum distance of plasma discharge. The optimal diameter of active electrode is between two to four times of optimum distance of plasma discharge, better at three times. The optimum discharge distance is the distance at which the efficiency of the transformation from electric energy into plasma is the maximum. This optimum distance of discharge depends on many parameters of the electric pulse, the dielectric material, its thickness, the active surface, etc.

Preferably, the system comprises a separator. According to one embodiment, the passive electrode is a separator.

The system comprises preferably a fine mesh filter with hydrophobic treatment.

For example, the separator is a fine mesh filter with hydrophobic treatment.

The system of the present invention consists of a safe, low voltage power supply unit, connected to a fully self-contained high voltage pulse generator, a plasma generator unit according to the principle of the dielectric barrier discharge (DBD) in which the active electrode is an electric wire with insulator layer used dielectric material, ability to be braided into different shapes and size, to emit plasma in all directions. Preferably, the system may comprise a self-operated power supply unit, for example at least one low voltage electrical battery. Preferably, low voltage power supply unit is an electric battery, of the type for a small household appliance, for example a 5 volts or 9 volts or 12/24 volts electric battery. According to another embodiment, the power supply is a AC/DC power adapter connected to the public or common network.

The system of the present invention may also have an additional separator arranged between the plasma discharge chamber and the liquid so that plasma streams and all plasma reactives species can pass through but avoiding the liquid to penetrate in the chamber. This feature ensures optimal reaction performed at all three regions in the chamber: gas region, gas/liquid boundary region and in liquid region.

The system of the present invention may also include an air circulation element or an air inlet, or a blowing system in order to increase the efficiency of the reactions between plasma reactives species and water.

The system of the invention can also be combined with remote control, wireless or wired connection to coordinate with each other and with other operations systems, regulating the activation process to the desired size on a large scale, generate large production capacity of Plasma Activated Water according to demand.

According to one embodiment, the system may comprise a buoyant structure. The system can be placed on the water surface.

According to another embodiment, the system comprises a plurality of active electrode.

According to another aspect, the invention proposes an appliance comprising at least one system according to the preceeding aspect. The appliance comprising at least a wall. The passive electrode of the system is at least a part of the at least wall.

According to yet another aspect, the invention proposes an assembly comprising a plurality of cold plasma generator systems, each system being linked to communication network and/or control means. The system, and/or the appliance, and/or the assembly may comprise one or a plurality of the following features, which may be combined or not, and combined or not with the preceeding features:

- at least one plasma generator generates cold plasma by the DBD (Dielectric Barrier Discharges) or SMD (Surface Micro Discharge) principle,

- the passive electrode is positioned parallel to the active electrode and may be part of a wall of an appliance,

- the passive electrode may be water itself (direct DBD principle),

- the plasma generator is installed close to the said wall,

- the plasma generator directly into water flow inside the pipe,

- a permeable but water-tight air filter is installed to prevent room of plasma generation being obstructed by water while staying close enough to discharge through the filter into water,

- an air exchanger is supplied by an external air pump,

- the system itself may be the air exchanger,

- the air exchanger is an air suction system working on the venturi principle,

- the air exchanger can be a vibrating membrane or a ventilation device installed near the plasma generator,

- the system is powered by a low voltage DC current or a battery,

- the system or appliance or assembly comprises an ON/OFF button, and is controlled by a control system or by the simple ON / OFF button,

- the system or appliance or assembly can be controlled by a remote-control system, wireless or pre-programmed in time or integrated into a process,

- the system or appliance or assembly is adapted for the process of cleaning and disinfecting portions of a circuit emptied after a cycle of use to prevent the development of microorganisms,

- the system or appliance or assembly is adapted for the process of activating water by plasma. According to yet another aspect, the invention proposes a method for installing a cold plasma generator system arranged to generate plasma gas according to the principle of Dielectric Barrier Discharge, the system comprising: a high voltage pulse generator supplied by a power supply unit, a plasma generator comprising at least one active electrode, a dielectric layer, and a passive electrode, the at least one active electrode is formed by at least one electrical wire surrounded by a dielectric layer, coupling means in order position and/or attach the preceding elements, the method comprising the following steps:

- measuring the area to be treated by said system,

- determining the plasma density, or plasma activated water compositions for application, to be applied on or in the area to be treated, shape the at least electrical wire surrounded by its dielectric layer so as to form at least one curvature.

Preferably, the cold plasma generator system comprises one or a plurality of the features of the first aspect.

Preferably the method comprises a step of determining the phenomena of plasma to be promote in order to select the right passive electrode connection.

Determination of plasma activated water compositions for application can be determined according for example sputtering direct plasma discharge or afterglow plasma diffusion phenomena.

Preferably, the electrical wire can be cut at the right or desired length.

According to one embodiment, the electrical wire is positioned thanks to attach means, for example brooch.

This method let to adjust the system or the plasma density to the customer application. Advantageous effects of the invention

The compact, customizable cold plasma generation system is suitable for differents equipment, is self-contained/self-operated/autonomous, customizable, safe and easy to use and maintain at the lowest cost possible.

Thanks to this plasma generator design in such a way that alloy a direct contact with the liquid in both stationary or continuous flows to generat Plasma Activated Water with optimal efficiency.

The fact that each module is low energy, only a few or tens Watts, for example less than 30 Watts, preferably between 1 to 15 watts or 5 to 10 watts, preferably 4 watts, will allow the use of basic components, security is much easier to implement, optimizing the cost and/or performance ratio.

In addition, this system when combined with renewable power sources such as solar cells, wind cells, etc. can work independently self-autonomy to enrich water for irrigation in agriculture, in marshes, fields, lakes etc. including remote areas.

In addition, the invention also serves to deploy on a large scale in agriculture thanks to the modularization, connectivation of the system allowing the establishment of a network of multiple Plasma modules synchronized to provide Plasma Activated Water.

Brief description of drawings

Fig 1 shows the reactions between plasma reactive species and liquid;

Fig 2a is a perspective view of a cold plasma generation system according to one embodiment of the invention;

Fig 2b is section view of the system of figure 2a;

Fig 3 is an example of high voltage pulse generator implemented in a system of the present invention; Fig 4 shows some examples of electrode’s shape and size according to several embodiments of the invention;

Fig 5 shows example of braid of two electrods;

Fig 6 is graph showing an example of the power in mW on the ordinate as a function of the distance in millimeters between the electrodes on the abscissa: how to identify the optimum distance for efficient plasma discharge;

Fig 7 is a perspective view of an example of first application using the cold plasma generation system according to one embodiment of the invention;

Fig 8 is a perspective view of an example of second application using the cold plasma generation system according to one embodiment of the invention;

Fig 9 is a perspective view of an example of a propeller’s blade with the cold plasma generation system according to one embodiment of the invention;

Fig 10 is a perspective view of an example of a faucet aerator cooperating/using the cold plasma generation system according to one embodiment of the invention;

Fig 11 is a perspective view of an example a sink plug anti odor represents the structure of a sterilizer according to one embodiment of the present invention.

Detailed description of the invention

The following detailed description is provided to help the reader in gaining a comprehensive understanding of the device described herein. The various parameters, variations and equivalents of the devices described herein will be apparent to others skilled in the art.

It should be noted that the terms used in the invention description are not intended to limit the invention but are used only to allow a clear and consistent understanding of the invention.

Accordingly, it is apparent to others skilled in the art that the following description of the invention is provided for the illustrative purposes only and is not intended to limit the invention as determined by the accompanying claims. Figures 2a and 2b show one embodiment of a fully customizable cold plasma generation system 100 according to the invention comprising:

• Low voltage power supply part 1;

• High voltage pulse generator 2 including: o insulating housing 2.1 covering the generator, o electronic main board 2.2, o user control panel 2.3, o high voltage transformer 2.4 generating high-voltage pulses;

• Plasma generator 3 including: o an active electrode 3.1, in a form of an electrical wire enclosed in a uniform dielectric material and connected to an output of the pulse generator 2, o a passive electrode 3.2 connects to the other output of the pulse generator 2 to ground the voltage with the solution medium. o a separator 3.3 between the plasma discharge layer and the surrounding solution, o optionnaly a vent hole or orifice 3.4.

According to different embodiments, the passive electrode can be:

- a part as such if opposite the electrode 3.1, or

- for example, a medium like water, a pipe/tank wall which is electrical connected to the other output of generator 2.

For example, separator may be a hydrophobic fabric, or a porous foam, or electrical conductor or non-conductor.

Power supply part 1 can be one or a plurality of the following parts: an AC/DC adapter, a regular battery, a rechargeable battery, a battery using renewable energy such as a solar cell or wind dynamo, flow, vibration, etc. or any other power source that supplies the electronic circuit board a direct or alternating current with low voltage, better Extra-low voltage (ELV) or safety extra-low voltage (SELV) or Protected extra- low voltage (PELV). The energy supplied does not exceed a few watts to a few tens of watts.

The electronic control board part 2.2 convert the electric energy from the power supply part 1 into electrical impulses that trigger the transformer 2.4 into hight voltage impulses respecting the parameters pre-programed and/or the instructions from the user control panel 2.3 like amplitude, oscilation frequency, frequency of impulse, etc.

The user control panel 2.3 can be a simple on/off switch or a graphic interface if the basic parameters of the board have been optimized and pre-programed in the system or will be conveyed via a remote control with wired or wireless connection from an external control device. The remote control has a wired (plug, socket) or wireless (antenna) such as WIFI, bluetooth, 4G, 5G, GPS etc. to receive and transmit control information from/to other devices or platforms.

The high voltage transformer 2.4 usually uses one of the booster principles to generate high voltages from a few tens volts to several tens kilovolts such as the transient high voltage generator principles. The particuliarity of this type of transformer is that in addition to high efficiency, very high boost speed, it also ensures safety against short circuit. An exemple of this transformer is shown in Fig 3.

The plasma generator 3 follows the principle of dielectric barrier discharge DBD in which there is at least one active electrode 3.1 forming an electric wire with the dielectric layer being the insulating sheath of that wire. In this embodiment, active electrode has a spiral shape. The active electrode is a wire, each end of which is connected to one output of the transformer 2.4. According to the example shown, the wire has two strands so as to form a closed loop connected to a single generator output. The two strands extend one beside the other and are wound in the form of a spiral, forming several portions in an arc of a circle, for example according to an arc of 180 degrees, spaced radially, see figures 2, 7 and 8.

This solution allows the active electrode to be formed into very different shapes and size (see Figure 4). For example, the active electrode may be formed like a zigzag shape, see picture a of Figure 4, or may be formed like a tubular (circular or non-circular) shapes, see picture b, c of Figure 4, the wire being wounded. For yet another example, the active electrode may be formed like a zigzag shape and then curved so as to form a circumferential shape; which may be repeated axially so as to form a circular tubular shape. For example, a complexe 3D forms like concave, convex, non-deployable or multilayer surface. The making of these shapes can be carried out by the integrator themselves according to their needs.

Similarly, the active electrode and/or the passive electrode may also have a conductive structure, usually bare, can be braided or shaped like in the Figure 4. According to the preceding examples, the wire can form a closed loop connected to a single generator output.

According to another embodiment represented by Figure 5, the active electrode may be braided with the passive electrode to form a uniform discharge space in 3 dimensions; passive electrode being also a wire. In particular, passive electrode is a wire without a dielectric or insulation layer surrounding the said wire. The discharge distance between the two electrodes kept stable even when they are deformed or shaken during installation or use.

Another solution of this present invention uses the external environment as the passive electrode 3.2. For example, the wall of a tube containing a solution with good electrical conductivity or the liquid to be activated can be used as passive electrode when connecting to the second output of the transformer. To do this, the active electrode is arranged near the tube wall or to approach the gas/solution interface with a sufficiently small distance, and preferably equivalent to the optimal discharge distance. For example, the optimal distance is superior than zero millimeter, for example is superior than 0.5 millimeter, for example is superior than 0.8 millimeter, for example is superior than 1 millimeter, for example is superior than 1.2 millimeter, for example is superior than 1.5 millimeter, for example is superior than 1.8 millimeter, for example is superior than 2 millimeters.

The optimum discharge distance is the distance at which the efficiency of the transformation from electric energy into plasma is the maximum. This optimum distance of discharge depends on many parameters of the electric pulse, the dielectric material, its thickness, the active surface, etc. But it can be identified by experimental measurements the power of plasma generated when the distance between the two electrodes increases from zero with the same input voltage. Exemple, for a generator generating electric impulses of 6 kV max from 7.4V DC input, frequency oscilation 100kHz, frequency of pulse at 10kHz and with the dielectric barrier in silicon at a thickness of 0.7 mm, the maximum distance of plasma discharge is about 2 millimeters and the optimum distance is about 0.8 millimeter (see Figure 6).

In this invention, in order to simplify installation, the active electrode is in contact to the passive electrode. Thanks to the wire forme, the plasma discharge chamber is in reality the space in the interstices/cavities between electrode wire and passive electrode. The diameter of wire impact directly the distance of plasma discharge. The optimal diameter of active electrode is between two to four times of optimum distance, better at three times. The density of braid or the distance between wire portion impacts the density of plasma discharge and the ventilation of gas exchange. It should not be zero to promote the ventilation of gas for good diffusion reactions.

The lenth of active electrod wire is calculated based on the optimal discharge surface to have homogeneous plasma (plasma streams covered all the surface active of electrode) but not too dense increasing the temperature in discharge chamber. The capacity of high voltage pulses generator (voltage, frequencies, energy, dielectric material) determines this parameter. For the example of generator here about, the density of plasma energy is between 0,07 to 0,5W/cm² with an electric wire of 2,2mm of diameter, the length is about 40cm max of the braided part; silicon for the insulation of the electric wire. This length can be adjusting (cut off) by user to adjust the density of plasma needed according to the required application or the power of the plasma generator and can be transformed in shape and dimension several times during its life cycle.

The feature of the separator 3.3 is so that the solution/medium/liquid does not penetrate into the plasma discharge space but at the same time does not interfere with the direct exchange of the reactive species and the solution/liquid/water in order to have diffusion reactions of Plasma Activated Water generation. For example, the use of a fine mesh filter with hydrophobic treatment allows gas to pass through but water does not. This solution has the limitation that the difference pressure between the gas and the water must be ensured so that the water pressure must be less than or not too high compared to the gas pressure which can overcome the surface tension of the filter. This separator can be placed on the opposite side of the active electrode compared to the passive electrode or in between or covering both electrodes to protect the plasma forming area.

One of the solutions is the separation layer or separator 3.3 can also be the passive electrode 3.2 when choosing a conductive material.

Applications

As Plasma Activated Water has many potential applications, there are also many possibilities for this invention integrate in home appliances as well as in agriculture, industry, medical etc.

First application

One of the applications of the present invention is a device used to generate Plasma Activated Water (PAW) on or above the surface of water, such as a jug of water, a storage reservoir, a toilet tank, a swimming pool, a rainwater tank, pond, lake, etc.

The device of this invention has a structure consisting of a PAW generation system as described above having the plasma generator 3 integrated in a floating structure 4 which ensures that the plasma discharge layer is always on the surface of the water and the active electrode 3.1 is always parallel and at a stable distance from the water surface as shown in Figure 7. This solution is suitable for PAW generation applications in static or low peristaltic water tanks. The establishment of pressure balance between air and water here thanks to the buoyant structure 4 ensures that the separator 3.3 is not subjected to a higher water pressure than the gas pressure. The PAW generated on the surface of water and diffuse naturally in. This system does not require an active ventilation system but air exchange naturally go through the gate of 3.4.

Depend on composition PAW needed, the plasma discharge can go directly to water thanks to the connection of passive electrode wire to water through the separator 3.3 or contrary to the conductive cover 3.2 in opposite side. This application can also integrate other organs such as heating, cooling, peristaltic flow generation systems inside the tank, providing other additional features for the application and also can increase the performance of PAW generation.

In the case of applications to activate water in the toilet tank, this system can be integrated on the floator that opens and closes the water source.

In the case of use for outdoor water tanks, ponds, lakes, this system can be combined with solar cells to form a completely independent device, floating on the surface of tanks, ponds, lakes that no need to wire it, no need to change or charge batteries manually. It can be controlled remotely by wireless network connection such as 4G/5G, WIFI, GPS, etc.

Second application

The application uses the Plasma Activated Water generation system as shown above integrating in a reservoir or in a pipeline 5. The PAW generation system has the plasma generator 3 submerged in water W and connect to a blowing system 6 that blows air into it (see Figure 8).

The plasma generator 3 can use either water or a part of the pipeline or reservoir wall as passive electrode 3.2. in the case of water, the electrical connection/passive electrode is bare wire immersed in water or glued against the wall of the tank or pipe.

The part 5 can be a water storage tank, swimming pool, bath, or simply a basin or a container for drinking water, domestic water in which the plasma generator 3 is submerged. It can also be a pipline communicate to them in open or close circuit.

The air blower 6 bring gas from the outside or on the surface of water and push down to the Plasma discharge chamber of PAW generation system. The blowing system 6 can be a pump which push air through the air exchange gate or hose 3.4 to the plasma discharge layer, creating a gas pressure higher than the water pressure on the surface of the separator 3.3 and pushing the gas into the solution/medium/liquid/water. Because the flow and gas pressure of the pump affect the efficiency and density of Plasma, in this application, it is necessary to have a function to adjust the flow or gas pressure during installation or use. In this application or in the following applications, air exchange gate comprises a hose mounted around or concentrically or coaxially to the electrical connections so that air can pass inside the hose and along electrical connections.

Third application

Another configuration for blowing air into the plasma generator is to integrate the plasma generators 3 on the blades of a propeller 200 (see Figure 9) which stirs the water, suck at the same time air through these generators to mix it all. To do this, the high voltage pulses generator 2 is integrated in the rotor and the plasma generators 3 are attached to the rear face of the propeller blades and connected to the ambient air through the center of the rotor. Thanks to the depression generated on the rear face of the blades when the propeller rotates and with the centrifugal force, the ambient air is sucked in through the center of rotor and propeling through the plasma discharge area to mixes with the water. The propeller can be turned by a motor like a water pump.

In other case, the blades can be also fixed inside a tube that create a turbulence in the water flow so the plasma generator 3 can take advantage of the venturi effect to suckin air to the plasma generating zone inside a pipline.

Fourth application

A particular configuration of this application is that it can be fitted to an outlet of the water supply system (faucet aerator) to activate water when it is opened (see Figure 10). The system is fixed to a hose 50.

The system comprises an active electrode 3.1 in the form of a wire, of the type defined above, wound in the form of a spiral so as to form a cone-shaped electrode. The system further comprises a separator 3.3 in the form of a cone whose dimensions are arranged to surround or encompass said electrode 3.1.

The dimensions of the electrode are chosen depending on the diameter of the hose in which the electrode is placed; for example the orientation of the cone shape of the electrode is between 30 and 80 degrees with respect to the transverse plane of the hose considered. For example, the separator 3.3 is spaced radially by a distance between 0.1mm and 2mm. The large diameter of the cone is arranged upstream and the smaller diameter of the cone is arranged downstream of the hose flow. The system includes an electrode cap or cover disposed on the large diameter end of the separator to deflect water to the outer surface of the separator. The volume delimited by the cap and the separator define an electrode chamber.

The system includes a pipe 3.4 connecting the cap to the outside of the hose.

According to the embodiment shown, the electrode is placed in downstream of a bend in the hose. The pipe 3.4 is straight.

The system includes two electrical connections. One of the electrical connections crosses pipe 3.4. The section, for example the diameter, of the pipe 3.4 is chosen so as to leave a space between the connection and the inner wall of the pipe, for example between 1mm and 5mm so as to allow air from the outside environment to pass to the electrode chamber.

Fifth application

In enclosed areas with moist air, ex. in drinking water distribution pipes when it’s not in use for some time, the proliferation of pathogenic microorganisms is common. Cleaning is complex because it usually needs to disassemble a part of the circuit to access.

According to yet another example, the system may be installed inside these closed areas, can generate plasma having the effect of sterilizing, disinfecting, eliminating fungi, deodorizing, avoiding the proliferation of microorganisms and those automatically.

In this application the plasma generator 3 does not necessarily have a separator 3.3 nor air circulation element 3.4.

Another application of the idea is integration in a sink plug anti odors (see Figure 11). Plasma generated periodically will limit microbial growth around and in the siphon area limiting the use of chemical product. In this application the active electrode 3.1 is wounded in form of spiral having a plurality of portions wounded radially and axially so as to form a concave-shaped electrode. In this application, the system comprises a passive electrode 3.2. The system is integrated just above the path of water. The system has a tubular shape and is disposed under the siphon grid. Preferably a control panel 2.3 is disposed parallel to the plane of the siphon grid. The control panel is disposed at an end of the system. Preferably the grid plane and the control panel are linked together and disposed in the same geometric plane. In particular, the control panel is disposed at a first axial end of the system, and the active electrode is disposed at a second axial end, opposite to the first axial end. The system is hence easy to use.

Preferably, it is proposed a sink plug appliance comprising a cold plasma generator system having a body in which a high voltage pulse generator 2, an electrical battery 1 are enclosed, and having a control panel disposed at a first axial end of the body, and an active electrode disposed at a second axial end of the body, opposite to the first axial end. According to this embodiment, the system comprises a skirt disposed at the periphery of the body. Preferably, the system comprises a siphon grid disposed at the first end of the body.

Claims

1. A cold plasma generator system (100) arranged to activate liquid in order to disinfect and inhibit the proliferation of harmful microorganisms, the system comprising:

- a high voltage pulse generator (2) supplied by a low power supply unit (1),

- a plasma generator (3) comprising at least one active electrode (3.1), a dielectric layer, and a passive electrode (3.2), wherein the system being arranged to generate plasma gas according to the principle of Dielectric Barrier Discharge, characterized in that the at least one active electrode (3.1) is formed by at least one electrical wire surrounded by a dielectric layer.

2. System according to claim 1, wherein between the dielectric layer and the electrical wire there is no gap and/or no junction and/or no welding or brazing or soldering.

3. System according to claim 1 or 2, wherein the high voltage pulse generator (2) comprises at least one output, and the at least one output is connected to at least one pair of two ends of an electrical wire.

4. System according to one of the preceeding claims 1 to 3, wherein the at least one electrical wire has at least one curvature.

5. System according to one of the preceeding claims 1 to 3, wherein the at least one electrical wire has at least one curvature so as form two portions which are substantially parallel or have a substantially parallel trajectory.

6. System according to one of the preceeding claims 1 to 3, wherein the at least one active electrode (3.1) having portions which are braided so as to form a braided layer.

7. System according to one of the preceeding claims 1 to 5, wherein the passive electrode (3.2) is formed by an electrical wire, preferably a bare wire, having passive portions and the active electrode (3.1) having active portions, active portions being braided with passive portions so as to form a braided layer composed of active wires and passive wires. System according to one of the preceeding claims, wherein the distance between two portions measured to at least one point of a portion is between 0 to 4 times a optimum distance of plasma discharge. System according to one of the preceeding claims 1 to 7, wherein the optimal diameter of active electrode is between two to four fold of optimum distance of plasma discharge, better at three fold. System according to one of the preceeding claims, comprising a separator (3.3), for example a fine mesh filter with hydrophobic treatment. System according to the preceeding claim, the passive electrode (3.2) is a separator (3.3). System according to one of the preceeding claims, comprising a blowing system (6). System according to one of the preceeding claims, comprising a self-operated power supply unit, for example at least one low voltage electrical battery. System according to one of the preceeding claims, comprising a buoyant structure (4). Appliance comprising a system according to one of the preceeding claims, comprising a wall, and the passive electrode is at least a part of the wall. Assembly comprising a plurality of cold plasma generator systems, each system being linked to communication network and/or control means. A method for installing a cold plasma generator system (100) arranged to generate plasma gas according to the principle of Dielectric Barrier Discharge, the system comprising:

- a high voltage pulse generator (2) supplied by a power supply unit (1),

- a plasma generator (3) comprising at least one active electrode (3.1), a dielectric layer, and a passive electrode (3.2), the at least one active electrode (3.1) is formed by at least one electrical wire surrounded by a dielectric layer,

- coupling means in order position and/or attach the preceding elements, the method comprising the following steps: measuring the area to be treated by said system,

- determining the plasma density to be applied on or in the area to be treated,

- shape the at least electrical wire surrounded by its dielectric layer so as to form at least one curvature.