Apparatus for generating plasma-activated liquid, equipment and methods for cleaning and / or sterilization

Abstract

The present invention relates to an apparatus for generating a plasma activated liquid, the apparatus comprising: A first planar electrode (1) and a second planar electrode (2), A first flat electrode (1) and a second flat electrode (2) separated from each other by a discharge space (3); A voltage is applied between the first planar electrode (1) and the second planar electrode (2), thus a voltage source (4) designed to ignite an electric discharge in the discharge space (3) between the first (1) and second (2) planar electrodes; and a liquid supply (5) designed to supply liquid to the discharge space (3) so as to form a liquid film (7) in the discharge space (3) that is exposed to the electric discharge when an electric discharge is ignited in the discharge space (3). Further aspects relate to an instrument comprising such a device and to a method for cleaning and / or sterilization using the device.

Description

Technical Field

[0001] The present invention relates to an apparatus for generating a plasma-activated liquid, a device including such an apparatus, and a method for cleaning and / or sterilizing.

Background Art

[0002] Transferring the chemical reactivity and energy of gaseous plasma to water or other liquids is a technical approach that can generate liquids with remarkable and transient broad-spectrum biological activity. When using water as the liquid, this process can produce so-called plasma-activated water (PAW). Due to the characteristics of PAW, it becomes an environmentally friendly solution in a wide range of biotechnology applications such as water treatment, surface cleaning, and biomedicine. The characteristics of PAW can also be utilized in various household appliances (Haushaltsgeraete).

[0003] However, systems known in the art for generating plasma-activated liquids are often very complex, and it is not possible to easily and reliably set the mixing ratio and dosing of the treatment liquid and the treatment gas. As a result, these systems often have unstable operations. For example, US 2004 / 0076543 A1 shows a system that uses plasma-treated water.

Summary of the Invention

[0004] The problem to be solved by the present invention is to overcome at least one drawback of the prior art. A further problem is to disclose an advantageous method for cleaning and / or sterilizing.

[0005] The problem is solved by the subject matter of the independent claims. The dependent claims relate to advantageous embodiments and further developments of the present invention.

[0006] An apparatus has been proposed for generating a plasma-activated liquid or plasma-activated fluid, comprising a first flat electrode and a second flat electrode, the first and second flat electrodes separated from each other via a discharge space. The apparatus also comprises a voltage source, which is designed to apply a voltage between the first and second flat electrodes, so that an electric discharge is ignited in the discharge space between the first and second flat electrodes. The apparatus also comprises a liquid supply unit, which is designed to supply liquid to the discharge space so that a liquid film exposed to the electric discharge is formed in the discharge space when the electric discharge is ignited in the discharge space.

[0007] A liquid film can form on one of the flat electrodes or on an object placed within the discharge space. Here, the term "liquid film" is used to describe a thin, continuous layer of liquid that wets a surface. A liquid film may differ from a bulky or lumpy liquid (voluminoesen Fluessigkeit) in its flow properties. A liquid can be described as a liquid film if its thickness is 1 mm or less.

[0008] During discharge within the discharge space, species in the gas within the discharge space, such as ozone, NOx, and / or peroxides, are activated. These activated species are released into the liquid film, thereby plasma-activating the liquid in the film.

[0009] Liquid films, compared to solid liquids, have a much larger surface area exposed to discharge within the discharge space, making them particularly suitable for use in devices for generating plasma-activated liquids. During discharge within the discharge space, the plasma chemistry induced by the discharge and energy transfer to the liquid film occur over the large surface area of ​​the liquid film.

[0010] During discharge within a discharge space, an exchange of active species occurs at the interface between the liquid film and the gas, generating active species in the gas due to the discharge. Because the liquid film has a large surface area, the exchange of active species occurs at a high exchange rate. A high exchange rate between active species is synonymous with high efficiency of the device. The use of a liquid film makes it possible to generate a plasma-activated liquid containing a high concentration of active species in a short time. Due to the thinness of the liquid film, the diffusion-limiting exchange rate within the liquid is high, and a new equilibrium of active species is rapidly established within the liquid.

[0011] Furthermore, by using a liquid film in a device that generates plasma-activated liquid, where the liquid in the liquid film is plasma-activated, it becomes possible to design a simple device with fewer complex structures. The liquid can be easily dosed by appropriately adjusting the liquid supply and, if necessary, the liquid discharge. Similarly, the gas to be used can be dosed by adjusting the gas supply and discharge flow rates. In this way, the mixing ratio of liquid and gas in the discharge space can be controlled as desired. The power stoichiometry in the plasma-activated gas and plasma-activated liquid can be easily controlled by a simple and robust dosing system. By selecting the temperature of the entire process in the discharge space, the vapor pressure of the liquid in the gas phase can be adjusted, and as a result, the composition of chemical species generated under energy supply can be changed. Easily adjustable parameters such as temperature, liquid flow rate, and gas flow rate can be used to control the plasma activation of the liquid and control the type of activated species generated.

[0012] An electrode can be described as "flaechig" if it is designed to induce a discharge on its surface. A flaechig electrode may have a substantially two-dimensional surface on which a voltage can be applied. A flaechig electrode can be planar and therefore can be placed substantially on a single plane. However, a flaechig electrode may also have a surface that forms the surface of a three-dimensional body, such as the surface of a cylinder, rather than being a planar plate. A flaechig electrode may have a surface on which a liquid film can form.

[0013] Preferably, the thickness of the liquid film is 0.2 mm or less, more preferably 0.1 mm or less. The thickness of the liquid film can be between 50 nm and 0.2 mm, preferably between 100 nm and 0.1 mm.

[0014] Furthermore, with liquid films less than 50 nm thick, openings are more likely to occur in the liquid film, and the liquid film may not continuously or consistently cover one or more of the flat electrodes, potentially causing uneven discharge. Uneven discharge can damage the device or shorten its lifespan. Preferably, this can be avoided by using a liquid film with a thickness of at least 50 nm.

[0015] In the case of a liquid film with a thickness of 0.2 mm or less, the ratio of the surface area to the volume of the liquid film is sufficiently large, so the exchange of active species at the interface between the liquid film and the gas in the discharge space is highly efficient. Furthermore, with a small liquid film thickness of 0.2 mm or less, the diffusion-limited exchange rate in the liquid is high, and a new equilibrium of active species can be rapidly established in the liquid.

[0016] When the liquid film has a preferred thickness of 100 nm to 0.1 mm, the formation of liquid film openings is eliminated even on substrates with poor wettability (schlecht benetzbaren), resulting in a very high efficiency of plasma activation.

[0017] The first flat electrode may have a dielectric layer facing the discharge space. Alternatively or additionally, the second flat electrode may have a dielectric layer facing the discharge space. If at least one of the two flat electrodes has a dielectric layer, the discharge is ignited as a dielectric barrier discharge.

[0018] The dielectric layer can cover a flat electrode on which a liquid film is placed. As a result, direct contact between the liquid film and the conductive contact surface of the flat electrode can be avoided. Alternatively or additionally, the dielectric layer can cover the flat electrode on which the liquid film is not placed. The dielectric layer can optimize the combustion behavior (Brennverhalten) during discharge.

[0019] The dielectric layer of the first flat electrode and / or the dielectric layer of the second flat electrode can be porous and / or rough. Porous and rough layers are characterized by good wettability with liquids. In particular, a liquid film can be formed on the dielectric layer. The porous or rough properties of the layer ensure that a liquid film remains on the layer and can be activated by plasma. The roughness or porosity of the layer ensures that the electrode has good wettability and facilitates homogeneous dosing of liquid and distribution of liquid to form a continuous liquid film. The good wettability of rough electrodes and / or porous electrodes always ensures clear separation of the liquid phase and the gas phase.

[0020] A porous layer can have small cavities. A layer can be considered porous if the volume of its cavities is at least 5%, preferably 10%, and especially 20% of the total volume of the layer. A layer is considered rough if its surface is not planar. Thus, the surface of a layer can have microscopic depressions and microscopic ridges that increase the surface area of ​​the layer and promote the formation of a liquid film.

[0021] The liquid supply unit can be designed to supply liquid to the discharge space such that the liquid forms a liquid film on the surface of a first flat electrode facing the discharge space. Preferably, this surface of the first flat electrode is formed by a dielectric layer. By forming a liquid film on the electrode, a simple and less complex device can be constructed in which a large surface area of ​​the liquid film is directly exposed to the discharge.

[0022] The first flat electrode may have a transport layer made of a porous material. The transport layer may form the surface of the first flat electrode facing the discharge space. The porous material of the transport layer may be dielectric. The liquid may move within the transport layer or form a liquid film on the surface of the transport layer. The transport layer has high porosity so that the liquid can move within the transport layer by capillary force.

[0023] Preferably, the liquid supply unit is designed to supply liquid to the transport layer such that the liquid moves through the transport layer and forms a liquid film on the surface of the transport layer. Using such a liquid supply unit, which introduces the liquid into the transport layer rather than directly coating the surface of the first electrode, allows for particularly precise dosing of the liquid. Since the liquid can be continuously re-dosed (nachdosiert) through the liquid supply unit, a liquid film of constant thickness can be maintained on the surface of the transport layer.

[0024] A porous body can be placed within the discharge space, separated from the first and second flat electrodes by gaps. The liquid supply unit can be designed to generate a liquid film on the surface of the porous body. Therefore, no porous film is formed on the electrodes themselves. Furthermore, the liquid film in the gap between the first electrode and the porous body, and the liquid film in the gap between the second electrode and the porous body, can be plasma activated. By using this additional porous body, more plasma-activated liquid can be generated in a single discharge space in this embodiment.

[0025] In one embodiment, a porous body can be placed in the discharge space, separated from the first and second flat electrodes by gaps, and the liquid supply unit is designed to generate a liquid film on the surface of the porous body facing the first flat electrode and a further liquid film on the surface of the porous body facing the second flat electrode, so that no liquid film is generated on the first and second flat electrodes. The porous body can be placed in the gap between the first and second electrodes.

[0026] The device can have a reaction chamber disposed within a discharge space. The reaction chamber can have a liquid extraction section designed to discharge a plasma-activated liquid. The liquid extraction section can be, for example, a valve. The liquid extraction section can enable the plasma-activated liquid to be extracted from the reaction chamber in a controlled manner.

[0027] The device can have a liquid reservoir for containing liquid. The liquid supply section can be designed to extract liquid from the liquid reservoir and supply it to the discharge space, and the device can have a liquid return channel designed to return liquid from the reaction chamber into the liquid reservoir. In this way, the liquid can be used within the circulation path and activated multiple times. Furthermore, the plasma-activated liquid can be accumulated within the liquid reservoir. The plasma-activated liquid can have different production and use locations. It is not necessary to use it immediately after production, and the activated liquid can be stored and used later. The plasma-activated liquid maintains an antibacterial effect over several months.

[0028] The device can have a gas reservoir, and the gas supply section is designed to extract gas from the gas reservoir and supply it to the reaction chamber. The device is designed to activate the gas within the discharge space during discharge. The gas can be circulated between the gas reservoir and the reaction chamber and activated multiple times. In this way, the activated gas can be accumulated in the gas reservoir.

[0029] The reaction chamber can be provided with a gas extraction section designed to discharge the activated gas. The activated gas can be used, for example, for cleaning or sterilization.

[0030] The device can have a recirculation channel designed to return the activated gas from the reaction chamber to the gas reservoir.

[0031] The liquid reservoir and the gas reservoir can be connected to each other, and the outlet of the recirculation channel can be located within the liquid reservoir, so that the activated gas released at the outlet of the recirculation channel flows through the liquid into the liquid reservoir. For example, the activated gas can be released in the form of bubbles. When flowing through the liquid in the liquid reservoir, the activated gas can release at least some of its active species into the liquid, resulting in enrichment with the active species.

[0032] The first and second flat electrodes can be planar or cylindrically symmetrical. If either the first or second flat electrode is cylindrically symmetrical, each electrode forms a cylindrical surface. This can be either the inner or outer surface of a hollow cylinder.

[0033] The liquid can only be moved within the apparatus by utilizing free convection. For example, this apparatus eliminates the need for an active pump element and moves the liquid solely through capillary force and gravity. This allows the apparatus to operate in an energy-efficient manner.

[0034] When a liquid film is formed on the first or second flat electrode, the liquid film can cool the respective electrode. Therefore, overheating of the discharge space can be avoided. Furthermore, the liquid can also be cooled by a cooling mechanism before being supplied to the discharge space.

[0035] A further embodiment relates to an apparatus having the above-described device for generating a plasma-activated liquid. This apparatus may be a household appliance, such as a floor care device, a cleaning robot, a coffee maker, a dishwasher, or a dryer. Alternatively, it may be another device, such as a water treatment device or a medical device used in biomedicine.

[0036] A further embodiment relates to a method for cleaning and / or sterilization. In this method, a plasma-activated liquid and / or plasma-activated gas can be generated using the apparatus described above, and the liquid and / or gas is used for cleaning and / or sterilization. [Brief explanation of the drawing]

[0037] In the following, preferred embodiments of the present invention will be described with reference to the figures.

[0038] [Figure 1] Figure 1 shows an example of a first embodiment of an apparatus for generating plasma-activated liquid. [Figure 2] Figure 2 shows a second embodiment of this device. [Figure 3] Figure 3 shows a third embodiment of this device. [Figure 4] Figure 4 shows a fourth embodiment of this device. [Figure 5] Figure 5 shows a fifth embodiment of this device. [Modes for carrying out the invention]

[0039] Figure 1 shows a first embodiment of an apparatus for generating a plasma-activated liquid. This apparatus has a first flat electrode 1 and a second flat electrode 2. These two flat electrodes are separated from each other by a discharge space 3.

[0040] Furthermore, the device is equipped with a voltage source 4, which is connected to the first flat electrode 1 and the second flat electrode 2. The voltage source 4 is designed to apply a voltage between the two flat electrodes 1 and 2. The voltage can be an AC voltage or a pulsed voltage. When the voltage source 4 applies a voltage between the two flat electrodes 1 and 2, an electric field with sufficient electric field strength to ignite the discharge is formed between the two flat electrodes 1 and 2 in the discharge space 3.

[0041] This device includes a liquid supply unit 5 that supplies liquid to the discharge space 3. The liquid can be, for example, water or another process liquid. In the embodiment shown in Figure 1, the liquid is applied from the liquid supply unit 5 to the first end of the surface 6 of the first flat electrode 1. The liquid flows along the surface 6 of the first flat electrode 1, forming a liquid film 7 on the surface 6 of the first flat electrode 1.

[0042] A liquid extraction section 8 is provided at the second end of the surface 6 of the first flat electrode 1, opposite to the first end. Liquid can be extracted from the first flat electrode 1 at the liquid extraction section 8. Between the liquid supply section 5 and the liquid extraction section 8, the liquid flows through the discharge space 3 as a liquid film 7. In the discharge space 3, the liquid is exposed to the discharge, thereby activating the plasma.

[0043] The first flat electrode 1 has a conductive contact surface 1a and a dielectric layer 1b. The conductive contact surface 1a can be a metal surface. The conductive contact surface 1a is connected to a voltage source 4, and a potential can be applied to the conductive contact surface 1a by the voltage source 4.

[0044] The dielectric layer 1b covers the conductive contact surface 1a such that the dielectric layer forms on the surface 6 of the first flat electrode 1 facing the discharge space 3. A liquid film 7 is formed on the surface 6 of the dielectric layer. During discharge, the dielectric layer 1b acts as a barrier, and the discharge is ignited as a dielectric barrier discharge (DBD).

[0045] The dielectric layer 1b is preferably rough and / or porous. The rough and / or porous layer is characterized by good wettability with liquids. The rough and / or porous design of the dielectric layer 1b ensures that a liquid film 7 can be formed on the dielectric layer and that the dielectric layer remains wetted with the liquid.

[0046] The second flat electrode 2 has a conductive contact surface 2a, which is connected to the voltage source 4. The conductive contact surface 2a of the second flat electrode 2 is not covered with a dielectric layer.

[0047] This apparatus also includes a gas supply unit 9 and a gas extraction unit 10. Gas is introduced into the discharge space 3 from the gas supply unit 9 and extracted from the discharge space 3 from the gas extraction unit 10. The direction of gas flow from the gas supply unit to the gas extraction unit can be reversed to the direction of liquid flow from the liquid supply unit 5 to the liquid extraction unit 8. The gas can be air or another process gas.

[0048] The discharge within the discharge space 3 generates chemical species, such as ozone, NOx, or peroxides, in the gas within the discharge space 3. The interface of the liquid film 7 is in contact with the gas and absorbs the chemical species generated from the gas phase of the gas at the interface. The gas is enriched with the generated species by the discharge and can also absorb vapors, such as water vapor, through exchange with the liquid film.

[0049] The liquid in the concentrated liquid film 7 becomes a plasma-activating liquid. The gas is also rich in chemical species and water vapor, and is therefore plasma-activated in the same way. In this manner, the apparatus generates a plasma-activating liquid and a plasma-activating gas.

[0050] Figure 2 shows a second embodiment of the apparatus for generating plasma-activated liquid.

[0051] According to the second embodiment, the first flat electrode 1 has a conductive contact surface 1a, a liquid distributor 11, and a porous transport layer 12, which are stacked together, and the porous transport layer 12 forms the surface 6 of the first flat electrode 1 that faces the discharge space 3.

[0052] The liquid distributor 11 is connected to the liquid supply unit 5. The liquid supply unit 5 supplies liquid to the liquid distributor 11, and the liquid is supplied to the porous transport layer 12 via the liquid distributor 11. The liquid distributor 11 can be a volume filled with liquid by the liquid supply unit 5. In the simplest embodiment, the liquid distributor 11 is a container. In alternative embodiments, the liquid distributor 11 can be a structural volume having, for example, a meander-shaped or channel-shaped distributor structure.

[0053] The porous transport structure 12 draws liquid from the liquid distributor 11 by capillary force. In the porous transport layer 12, the liquid moves through the transport layer 12 by capillary force, spreading out and forming a liquid film 7 on the surface of the porous transport layer 12. The liquid can be continuously re-administered through the liquid distributor 11. The liquid film 7 on the surface 6 of the porous transport structure is exposed to the discharge in the discharge space 2. As a result, the liquid film 7 is plasma-activated, as described in relation to the first embodiment example.

[0054] In the embodiment shown in Figure 2, the second flat electrode 2 is covered with a dielectric layer 2b. The dielectric layer 2b forms a dielectric barrier with respect to the discharge space 3, and therefore the discharge is ignited as a dielectric barrier discharge. The liquid in the liquid film 7 formed on the surface 6 of the first flat electrode 1 is activated by the dielectric barrier discharge and can be extracted as activated liquid in the liquid extraction section. In particular, the liquid can be moved from the surface of the first flat electrode 1 to the liquid extraction section 8 by gravity.

[0055] The liquid in the liquid distributor 11 is located between the conductive contact surface 1a of the first flat electrode 1 and the second flat electrode. In other words, during discharge, the liquid in the liquid distributor 11 is present in the current path. In order to prevent the discharge from being adversely affected by the liquid, the liquid must have a certain conductivity.

[0056] Figure 3 shows a third embodiment. The third embodiment is a modification of the second embodiment, in which the position of the first flat electrode is changed.

[0057] In the third embodiment, the first flat electrode is positioned between the liquid distributor 11 and the transport layer 12. The first flat electrode has an opening through which the liquid passes from the liquid distributor 11 to the porous transport layer 12.

[0058] In the third embodiment, the liquid in the liquid distributor 11 is not placed in the current path during discharge. Therefore, there are no restrictions on the liquid that can be used in the third embodiment.

[0059] Figure 4 shows an apparatus for generating a plasma-activated liquid according to a fourth embodiment.

[0060] The fourth embodiment differs from the previous embodiments in that the liquid and gas each circulate in separate circuits. The fourth embodiment further differs from the first to third embodiments in that the liquid film 7 is not formed on the surface of one of the two flat electrodes 1 and 2, but is placed in the discharge space 3 and formed on a porous body 13 separated from the first flat electrode 1 and the second flat electrode 2 via gaps 14.

[0061] These two differences should be considered separately and can also be provided individually in alternative embodiments of the embodiments shown in Figures 1, 2, or 3. In particular, the liquid film 7 can be formed on the porous body 13 in the discharge space 3 without the gas and / or liquid being circulated. Alternatively, the gas and / or liquid can be circulated to form the liquid film 7 on one surface of both flat electrodes 1, 2.

[0062] The apparatus shown in Figure 4 has a reaction chamber 15. The first flat electrode 1 and the second flat electrode 2 are located inside the reaction chamber 15. The discharge space 3 between the two electrodes 1 and 2 is also located inside the reaction chamber 15. The porous body 13 is located inside the discharge space 3. The liquid supply unit 5 supplies liquid to the porous body 13. For this purpose, for example, the liquid can be dripped onto the porous body 13. Alternatively, the liquid supply unit 5 may have an outlet that abuts the porous body 13 or a tube that is surrounded by the porous body 13.

[0063] The liquid passes through the porous body 13 by capillary force, moves along the surface of the porous body 13, and forms a liquid film 7 on the surface of the porous body 13. Here, the discharge is ignited in the gap 14 between the first flat electrode 1 and the porous body 13, and in the gap 14 between the second flat electrode 2 and the porous body 13. The discharge in the discharge space 3 generates chemical species, such as ozone, NOx, or peroxides, in the gas. At the interface between the liquid film and the gas, an exchange of chemical species and water vapor occurs. This activates the liquid film with the chemical species. Similarly, the gas is enriched with chemical species and water vapor.

[0064] The liquid film 7 flows along the surface of the porous body 13 and, due to gravity, drips into the collection container 16 located beneath the porous body 13, where the plasma-activated liquid is collected.

[0065] The reaction chamber 15 is gas-sealed and liquid-sealed to prevent the uncontrolled outflow of plasma-activating gases, particularly ozone. However, the reaction chamber 15 has inlets and outlets for the gases and liquids described below. The reaction chamber 15 has a liquid outlet 8 through which the plasma-activating liquid can be removed from the recovery container 16. The removed liquid can be used for desired purposes such as cleaning, sterilization, and activation. The reaction chamber 15 also has a gas outlet 10 through which the activating gas can be removed from the reaction chamber 15. The activating gas can also be used for purposes such as cleaning, sterilization, and activation.

[0066] The apparatus shown in Figure 4 also includes a liquid reservoir 17 and a gas reservoir 18. The gas reservoir 18 and the liquid reservoir 17 can be connected to each other and, for example, can be formed into a single container.

[0067] This device has a liquid return channel 19 through which the plasma-activated liquid can be taken from the collection container 15 and supplied to the liquid reservoir 17. Thus, the liquid can move within the circulation path, and the liquid is first taken from the liquid reservoir 17 by the liquid supply unit 5 and supplied to the porous body 13. After plasma activation in the discharge space 3, the liquid enters the collection container 15, and is then either taken out by the liquid extraction unit 8 and used, or returned to the liquid reservoir 17 via the liquid return channel 19. In this way, the plasma-activated liquid can be collected in the liquid reservoir 17.

[0068] Gas can be withdrawn from the reaction chamber 15 via a recirculation channel 20 and supplied to a gas reservoir 18. The outlet 21 of the recirculation channel 20 can be located within the liquid reservoir 17. The gas returned from the discharge space 3 to the gas reservoir 18 therefore flows first through the liquid reservoir 17. For example, the outlet 21 of the recirculation channel 20 may have a bubble pattern that ensures the recirculated gas rises through the liquid in the form of bubbles. At least some of the active species from the recirculated gas enter the liquid and enrich the liquid in the liquid reservoir 17.

[0069] The gas is guided through the circulation path. The gas is first in the gas reservoir 18, from where it is drawn by the gas supply unit 9 and supplied to the discharge space 3. In the discharge space 3, the gas is activated by the discharge. After that, the gas is either drawn out by the gas extraction unit 10 or returned from the discharge space 3 to the gas reservoir 18 via the recirculation channel 10.

[0070] The control of liquid and gas circulation paths can be performed by elements whose operation is controlled by differential pressure, particularly pumps, valves, and throttles.

[0071] The gas reservoir 18 and the liquid reservoir 17 may each be equipped with re-dosing mechanisms 17a and 18a, respectively. Fresh liquid can be supplied to the liquid reservoir via the re-dosing mechanism 17a. Fresh gas can be supplied to the gas reservoir 18 via the re-dosing mechanism 18a. In this way, the extraction of liquid via the liquid extraction unit 8 and the extraction of gas via the gas extraction unit 10 can be balanced.

[0072] The chemical composition of the circulating liquid and gas can be adjusted via reintroduction mechanisms 17a and 18a. The ratio of fresh inactive gas to activated gas can be set as needed. The ratio of fresh inactive liquid to activated liquid can also be set.

[0073] A pump can also be placed inside the container, which causes the liquid to circulate within the liquid reservoir 17.

[0074] Figure 5 shows a cross-section of the apparatus according to the fifth embodiment. In the first to fourth embodiments, the flat electrodes 1 and 2 were substantially two-dimensional surfaces extending on a plane. In the fifth embodiment, the first flat electrode 1 and the second flat electrode 2 are each curved in a cylindrical shape. The first flat electrode 1 forms an inner cylinder, and the second flat electrode forms an outer cylinder, with both cylinders arranged concentrically. The outer cylinder surrounds the inner cylinder.

[0075] The discharge space 3 is located in the cavity between the cylinder formed by the first flat electrode 1 and the cylinder formed by the second flat electrode 2. The discharge space 3 is ring-shaped or sleeve-shaped.

[0076] The fifth embodiment is based on the first embodiment. The liquid film 7 is formed on the surface of the dielectric layer 1b facing the discharge space 3, as described in relation to the first embodiment. Since both flat electrodes 1 and 2 are curved in a three-dimensional cylindrical shape, the area on which the liquid film can be formed is increased, and more plasma-activated liquid can be generated.

[0077] In another embodiment, the second flat electrode 2 can form an inner cylinder, and the first flat electrode 1 can form an outer cylinder.

[0078] Furthermore, in the second, third, and fourth embodiments, the first flat electrode 1 and the second flat electrode 2 can also be curved into a cylindrical shape. The first flat electrode 1 can form an inner cylinder and the second flat electrode 2 can form an outer cylinder. Alternatively, the first flat electrode 1 can form an outer cylinder and the second flat electrode 2 can form an inner cylinder.

[0079] In the fourth embodiment, the porous body 13 is annular in this alternative embodiment. The annular porous body 13 is located in an annular discharge space 3 between a first flat electrode 1 that forms a cylinder and a second flat electrode 2 that also forms a cylinder.

[0080] The plasma-activated liquid produced by the apparatus according to one of the embodiments shown here can be used for a variety of applications. For example, the liquid can be stored in a container and used as a regenerative cleaning agent (regeneratives Putzmittel). This liquid retains its beneficial properties for cleaning and sterilization for several months.

[0081] The liquid can be poured into a spray bottle and used by spraying. Alternatively, the liquid can be soaked into a sponge and applied to the surface to be treated via the sponge. It can also be dispensed or applied to a cloth. The liquid can be used to clean, maintain, or disinfect objects, such as mouthpieces or orthodontic appliances, in a dry or humid chamber, for example, in a dishwasher.

[0082] This device can be incorporated into various household appliances that utilize plasma-activated liquid for cleaning, sterilization, and activation. For example, it can be used in floor care machines, cleaning robots, and coffee makers for cleaning and descaling. It can also be incorporated into dishwashers, washing machines, and dryers to take advantage of the beneficial properties of plasma-activated liquid and plasma-activated gas. [Explanation of Symbols]

[0083] 1. First flat electrode (erste flaechige Elektrode) 1a Conductive contact surface (leitfaehige Kontaktflaeche) 1b Dielectric layer 2 Second flat electrode (zweite flaechige Elektrode) 2a Conductive contact surface (leitfaehige Kontaktflaeche) 2b Dielectric layer 3 Discharge space (Entladungsraum) 4. Voltage source (Spannungsquelle) 5 Fluid supply section 6. Surface of the first flat electrode (Oberflaeche der ersten flaechigen Elektrode) 7 Fluessigkeitsfilm 8 Fluid outlet (Fluessigkeitsentnahme) 9. Gas Supply Department (Gaszufuhr) 10. Gas outlet (Gasentnahme) 11 Fluidverteiler 12. Transport Layer (Transportschicht) 13. Porous material (poroeser Koerper) 14. Gap (Spalt) 15. Reaction Chamber 16. Collection container (Sammelbehaelter) 17. Liquid reservoir (Fluessigkeitsreservoir) 17a Re-administration mechanism 18. Gas reservoir 18a Re-administration mechanism 19. Liquid return channel (Fluessigkeits-Rueckfuehrkanal) 20. Rezirkulation channels 21 Outlet (Auslass)

Claims

1. A device for generating plasma-activated liquid: A first flat electrode and a second flat electrode separated from each other by a discharge space, A voltage source designed to apply a voltage between the first flat electrode and the second flat electrode, so that a discharge is ignited in the discharge space between the first flat electrode and the second flat electrode, A liquid supply unit is designed to supply liquid to the discharge space such that a liquid film exposed to the discharge is formed within the discharge space when the discharge is ignited within the discharge space. Equipped with, The liquid is plasma-activated by the discharge within the liquid film. The apparatus has a reaction chamber, and the discharge space is arranged inside the reaction chamber. The reaction chamber has a liquid extraction section designed to release a plasma-activated liquid, The apparatus has a liquid reservoir for containing the liquid, The liquid supply unit is designed to take the liquid from the liquid reservoir and supply the liquid to the discharge space. The apparatus has a return channel designed to return the liquid from the reaction chamber back into the liquid reservoir. Device.

2. The liquid film has a thickness between 50 nm and 0.2 mm. The apparatus according to claim 1.

3. The first flat electrode has a dielectric layer facing the discharge space, and / or The second flat electrode has a dielectric layer facing the discharge space. The apparatus according to claim 1.

4. The dielectric layer of the first flat electrode is porous and / or rough. The dielectric layer of the second flat electrode is porous and / or rough. The apparatus according to claim 3.

5. The liquid supply unit is designed to supply the liquid such that the liquid forms a liquid film on the surface of the first flat electrode facing the discharge space. The apparatus according to claim 1.

6. The first flat electrode has a transport layer of porous material that forms the surface of the first flat electrode facing the discharge space, The apparatus according to claim 1.

7. The liquid supply unit is designed to supply the liquid from the transport layer, and therefore the liquid moves through the transport layer to form the liquid film on the surface of the first flat electrode. The apparatus according to claim 6.

8. A porous body is placed within the discharge space, separated from the first flat electrode and the second flat electrode by gaps. The liquid supply unit is designed to generate the liquid film on the surface of the porous body. The apparatus according to claim 1.

9. A porous body is arranged within the discharge space, separated from the first flat electrode and the second flat electrode by gaps. The liquid supply unit is designed to generate a liquid film on the surface of the porous body facing the first flat electrode, and to generate a further liquid film on the surface of the porous body facing the second flat electrode. No liquid film is formed on the first flat electrode and the second flat electrode. The apparatus according to claim 1.

10. The device has a gas reservoir, The gas supply unit is designed to extract gas from the gas reservoir and supply the gas to the reaction chamber. The apparatus is designed to activate the gas in the discharge space during the discharge. The apparatus according to claim 1.

11. The apparatus has a recirculation channel designed to return the plasma-activated gas from the reaction chamber to the gas reservoir. The apparatus according to claim 10.

12. The liquid reservoir and the gas reservoir are connected to each other, the outlet of the recirculation channel is located within the liquid reservoir, and therefore the plasma-activated gas released at the outlet of the recirculation channel flows through the liquid within the liquid reservoir. The apparatus according to claim 11.

13. The reaction chamber has a gas extraction section designed to release a plasma-activating gas, The apparatus according to claim 1.

14. The first flat electrode is planar or cylindrically symmetric, and / or The second flat electrode is symmetrical in either the plane or the cylinder. The apparatus according to claim 1.

15. The apparatus lacks an active pump element, and the liquid within the apparatus moves only by capillary force and gravity. The apparatus according to claim 1.

16. The liquid film cools the first flat electrode and / or the second flat electrode. The apparatus according to claim 1.

17. An apparatus for generating a plasma-activated liquid, comprising: A first flat electrode and a second flat electrode separated from each other by a discharge space, A voltage source designed to apply a voltage between the first flat electrode and the second flat electrode, so that a discharge is ignited in the discharge space between the first flat electrode and the second flat electrode, A liquid supply unit is designed to supply liquid to the discharge space such that a liquid film exposed to the discharge is formed within the discharge space when the discharge is ignited within the discharge space. Equipped with, The liquid is plasma-activated by the discharge within the liquid film. A porous body is placed within the discharge space, separated from the first flat electrode and the second flat electrode by gaps. The liquid supply unit is designed to generate the liquid film on the surface of the porous body. Device.

18. An apparatus comprising the device described in claim 1 or 17.

19. The aforementioned device is a household appliance such as a robotic vacuum cleaner, a coffee maker, a dishwasher, or a dryer, or The aforementioned equipment is either water treatment equipment or medical equipment. The apparatus according to claim 18.

20. A plasma-activated liquid is generated by the apparatus according to claim 1 or 17. The plasma-activated liquid is used for cleaning and / or sterilization. method.

21. A method for washing and / or sterilization, A plasma-activated gas is generated by the apparatus according to claim 1 or 17, The plasma-activated gas is used for cleaning and / or sterilization. method.

Images