METHOD FOR DISINFECTING COMPONENTS OF A FILLING SYSTEM AND FILLING SYSTEM

Description

[0001] The invention relates to methods for disinfecting a surface and to methods for disinfecting components of a filling system and / or materials used in the operation of the filling system. Furthermore, the invention relates to a filling system. Furthermore, the invention relates to a method and a device for producing plasma-activated water and to the use of plasma-activated water.

[0002] Food filling plants, such as beverage filling plants, are subject to strict hygiene regulations. In particular, certain components of the filling plants must be regularly disinfected. The same applies to the materials used in the operation of the filling plants, especially the containers into which the food is filled and the closures for the containers.

[0003] Currently, the disinfection of components in a filling plant is achieved by interrupting operation of the plant at regular intervals and exposing the components to be disinfected to a highly concentrated aqueous hydrogen peroxide solution, which kills germs, particularly bacteria. In some plants, the hydrogen peroxide solution is also applied during operation. To reliably achieve the disinfectant effect, a hydrogen peroxide solution with a concentration of at least 30% is typically used for disinfection. Since disinfection must be carried out at very regular intervals, this has the disadvantage that the operator of a filling plant must maintain relatively large quantities of hydrogen peroxide in order to ensure safe and compliant operation of the filling plant.In addition, hydrogen peroxide solutions have a limited shelf life, which makes extensive storage difficult.

[0004] In addition to disinfecting components of a filling line, aqueous hydrogen peroxide solutions are also used to disinfect other surfaces, such as hospital floors. These applications also require a relatively high hydrogen peroxide concentration of at least 30% by weight, so large quantities of hydrogen peroxide or prepared hydrogen peroxide solutions must be stored.

[0005] Alternatively, plasma disinfection, known from JP2001054556A, WO2017064741A1, and WO2007071720A1, can be used. In these sterilization processes, a cleaning fluid in gaseous and / or nebulized form is mixed with the working gas of a plasma source or injected into a plasma jet. In the processes described in these publications, the plasma exposure occurs only after the (not yet plasma-activated) fluid has evaporated or nebulized.

[0006] Against this background, the object of the present invention is to provide a method for disinfecting surfaces, in particular components of a filling plant and / or materials used in the operation of the filling plant, with which the aforementioned disadvantages are avoided or at least reduced.

[0007] According to a first aspect of the present disclosure, this object is achieved according to claim 1 by a method for disinfecting components of a filling system, in which the components to be disinfected are exposed to plasma-activated water, wherein the plasma-activated water is evaporated, sprayed and / or atomized for exposure to the components to be disinfected.

[0008] According to the first aspect, this object is further achieved, according to claim 3, in a filling system which is designed to fill a product into containers and has means for applying a cleaning liquid to components of the filling system, wherein the means are designed to apply plasma-activated water to the components, and wherein the means comprise one or more nozzles designed to spray plasma-activated water onto the components to be disinfected, and / or one or more evaporators designed to evaporate plasma-activated water in the region of the components to be disinfected, and / or one or more atomizers designed to atomize plasma-activated water in the region of the components to be disinfected, according to the invention in that the means are connected to a reservoir,which contains plasma-activated water, or that the loading means are connected to a device for producing plasma-activated water.

[0009] Plasma-activated water is water that has been activated by the action of a working gas emerging from an atmospheric plasma source. In particular, the water can be directly exposed to atmospheric plasma, such as an atmospheric plasma jet, i.e., to a working gas emerging from the plasma source that is at least partially still in the plasma state. Furthermore, the water can also be exposed to the working gas emerging from the plasma source after the working gas has already been recombined, i.e., is no longer in the plasma state. It has been found that even such a recombined working gas still contains sufficient reactive species, such as ozone or nitrogen oxides, to form relatively long-lived reactive species in the water, such as hydrogen peroxide, nitric acid, or nitrous acid.

[0010] Accordingly, the plasma-activated water can be produced or has been produced by the action of a working gas emerging from an atmospheric plasma source on (in particular liquid) water.

[0011] It was recognized that by activation using an atmospheric plasma or the recombined working gas, the water can be enriched with reactive species that persist in the water for a longer period of time and show a good disinfection effect when the plasma-activated water is applied to a surface to be disinfected.

[0012] In contrast to conventional hydrogen peroxide solutions, the use of plasma-activated water has the advantage that hydrogen peroxide does not need to be stored, or at least only in smaller quantities, since the hydrogen peroxide and possibly other reactive species are formed in the water through plasma activation. Furthermore, it has been found that plasma-activated water exhibits the same disinfection effect as a conventional hydrogen peroxide solution without plasma activation, even at lower hydrogen peroxide concentrations.

[0013] For the production of plasma-activated water, water mixed with hydrogen peroxide can also be used, in particular an aqueous hydrogen peroxide solution with a hydrogen peroxide concentration of preferably 1 to 10 wt.%. Such a hydrogen peroxide solution can then be plasma-activated by exposure to a working gas emerging from an atmospheric plasma source. It has been found that by maintaining a certain hydrogen peroxide concentration in the water prior to plasma activation, an even better sterilizing effect of the resulting plasma-activated water can be achieved.

[0014] The process is used to disinfect components of a filling system. The components of the filling system to be disinfected can, in particular, be parts of the filling system that come into contact with the product being filled, especially food, or with the materials used in the operation of the filling system.

[0015] The filling system's pressurizing devices are designed to pressurize the components with plasma-activated water. For this purpose, the pressurizing devices are connected to a reservoir containing plasma-activated water or to a device for producing plasma-activated water. This has the advantage that the plasma-activated water can be produced as needed and used directly, eliminating the need for storage.

[0016] The filling system is designed to fill a product, in particular a food product, into containers, in particular into similar containers. For this purpose, the filling system preferably comprises a filling device with a filling nozzle from which the product to be filled emerges during operation, and with a container guide for positioning a container below the filling nozzle.

[0017] Furthermore, the filling system preferably comprises transport means configured to transport containers one after the other through the filling system. For example, the transport means may comprise a filling carousel, with which the containers are moved along a circular path under moving filling nozzles for filling.

[0018] The filling system can also have a cleaning device upstream of the filling device for cleaning the containers before filling. For example, the transport means can first transport the containers through a cleaning line where they are cleaned before being transported to or through the filling system.

[0019] The cleaning section can, for example, have a loading device for loading the containers with a cleaning liquid, and optionally a rinsing device downstream of the loading device for rinsing cleaning liquid residues from the containers.

[0020] The application device can be configured, in particular, to apply plasma-activated water to the containers. For example, nozzles can be provided that apply plasma-activated water to the outer surfaces of the containers.

[0021] Furthermore, nozzles can also be provided to apply plasma-activated water to the inside of the containers. Alternatively, plasma sources can be provided that are designed to apply atmospheric plasma to the inside of the containers.

[0022] The filling system can further comprise a closing device for closing the containers, for example, with separate closures or by welding or gluing the container. Preferably, the filling system can also comprise a cleaning device for cleaning closures used to close the containers. In particular, the cleaning device can comprise means for applying plasma-activated water to the closures.

[0023] Plasma-activated water is required for the method and bottling plant described above. Against this background, a device for producing plasma-activated water can be provided, comprising an activation chamber for accommodating a volume of water, a disc aerator having a gas-permeable membrane adjacent to the activation chamber, and a plasma source for generating an atmospheric plasma in a working gas. The plasma source has a nozzle opening from which the working gas exits during operation. The plasma source is connected to the disc aerator in such a way that the working gas exiting the plasma source during operation passes through the membrane of the disc aerator into the activation chamber.

[0024] The plasma-activated water can be produced by a method for producing plasma-activated water, in particular using the device described above, in which an atmospheric plasma is generated in a working gas in a discharge space of a plasma source, preferably by means of dielectrically impeded discharge, and in which the working gas is introduced from the discharge space into a water volume via a disc aerator.

[0025] It was found that the working gas can be introduced into the water particularly well via a disc aerator in order to enrich reactive species in the water and thus produce plasma-activated water.

[0026] The device for producing plasma-activated water comprises an activation chamber for accommodating a volume of water, as well as a disc aerator having a gas-permeable membrane bordering the activation chamber. The activation chamber can be formed, for example, by a container, such as a glass cylinder, with a disc aerator provided on the underside, so that the gas-permeable membrane forms the floor of the activation chamber. The gas-permeable membrane can, for example, be a membrane with a multitude, preferably thousands of small openings, through which the gas is introduced in the form of small bubbles into the volume of water in the activation chamber. The membrane can be made, for example, of a plastic or rubber, such as ethylene propylene diene rubber (EPDM).

[0027] The device for producing plasma-activated water further comprises a plasma source for generating an atmospheric plasma in a working gas. The plasma source can be configured, in particular, to generate the plasma by means of dielectrically impeded discharges. For this purpose, the plasma source preferably comprises two electrodes with a discharge space arranged therebetween, wherein at least one of the electrodes is insulated from the discharge space by a dielectric, for example a ceramic. Furthermore, a power supply is preferably provided, which is configured to apply a high-frequency high voltage to the electrodes. During operation, the two electrodes are supplied with a high-frequency high voltage via the power supply.Since the dielectric prevents direct discharges between the electrodes, so-called dielectrically hindered discharges, also known as dielectric barrier discharges, occur in the discharge space.

[0028] The high-frequency high voltage for operating the plasma source preferably has a voltage amplitude in the range of 1 kV to 40 kV, preferably 5 kV to 20 kV, at a frequency in the range of 10 kHz to 40 kHz, preferably 12 kHz to 18 kHz. It has been found that operating the plasma source at a frequency in the range of 12 kHz to 18 kHz generates a particularly high amount of ozone, which allows for a particularly effective disinfection of the plasma-activated water.

[0029] The high-frequency high voltage required to operate the plasma source is the voltage present between the electrodes during operation. For example, when using a transformer to operate the plasma source, this voltage is the secondary voltage.

[0030] The plasma source has a nozzle opening from which the working gas emerges during operation. The working gas flowing through the plasma source during operation comes into contact with the dielectrically impeded discharges occurring in the discharge chamber and is thereby at least partially converted into the plasma state, generating an atmospheric plasma. The plasma generation creates reactive species in the working gas, such as ozone or nitrogen oxides, which remain at least partially present in the working gas even after recombination of the working gas. The working gas emerging from the nozzle opening of the plasma source therefore contains reactive species, even if the components of the working gas ionized in the discharge chamber have already recombined, so that the working gas is no longer in the plasma state at the nozzle opening.

[0031] Air is the preferred working gas. In addition to its easy availability, this also allows the plasma-activated water to achieve particularly effective disinfection.

[0032] In the device for producing plasma-activated water, the plasma source is connected to the disc aerator in such a way that the working gas escaping from the plasma source during operation passes through the disc aerator's membrane into the activation chamber. For this purpose, the nozzle opening of the plasma source is directly connected to the disc aerator, in particular via a pipe.

[0033] Plasma-activated water, in particular produced with the device and / or with the method described above, can be used in particular for disinfecting components or materials of a filling rack.

[0034] In particular, it has been shown that plasma-activated water can be stored for extended periods of several days or even weeks without losing its disinfectant effect. The use of the plasma-activated water can therefore be separated in time and / or space from the production of the plasma-activated water. For example, the plasma-activated water can simply be stored in liquid form after production and before use.

[0035] In the following, various embodiments of the disinfection method and the filling system are described, whereby the individual embodiments apply independently of one another to the method and the filling system and can also be combined with one another.

[0036] In the first embodiment of the disinfection method, the plasma-activated water is produced using the previously described method for producing plasma-activated water. In a further embodiment, the plasma-activated water is produced using the previously described method for producing plasma-activated water. It has been found that the plasma-activated water produced using the previously described method is particularly well suited for disinfecting components of a bottling plant and materials used in the operation of the bottling plant, as it has a high concentration of persistent species that effect reliable disinfection and thus ensure safe operation of the bottling plant.

[0037] In a further embodiment of the disinfection method, the plasma-activated water is sprayed onto the components and / or materials to be disinfected. In a corresponding embodiment of the filling system, the application means comprise one or more nozzles configured to spray plasma-activated water onto the components and / or materials to be disinfected.

[0038] In a further embodiment of the disinfection method, the plasma-activated water is evaporated for application to the components and / or materials to be disinfected. In a corresponding embodiment of the filling system, the application means comprise one or more evaporators configured to evaporate plasma-activated water in the area of the components and / or materials to be disinfected.

[0039] In a further embodiment of the disinfection method, the plasma-activated water is atomized or nebulized for application to the components and / or materials to be disinfected. In a corresponding embodiment of the filling system, the application means comprise one or more atomizers configured to atomize or nebulize plasma-activated water in the area of the components and / or materials to be disinfected.

[0040] The plasma-activated water is therefore primarily in liquid form before being applied to the components and / or materials to be disinfected. This allows for easy storage, allowing the production of the plasma-activated water and its use for disinfection to be separated in time and / or space. For application to the components and / or materials to be disinfected, the plasma-activated water can then be vaporized, sprayed, and / or atomized accordingly, in order to achieve uniform wetting of the surfaces to be disinfected.

[0041] By evaporating, spraying, and / or atomizing or nebulizing the plasma-activated water, it can be distributed finely and extensively over the components or materials to be disinfected, enabling comprehensive disinfection. It has been found that the disinfection effect of plasma-activated water remains sufficiently high even after evaporation, spraying, and / or nebulizing.

[0042] In a further embodiment of the filling system, a device for producing plasma-activated water is provided, in particular the previously described device for producing plasma-activated water, and the pressurizing means are connected to the device for producing plasma-activated water in such a way that plasma-activated water produced by the device for producing plasma-activated water is directed to the pressurizing means. In this way, the plasma-activated water required for disinfection can be produced as needed and used directly for disinfection. This eliminates the need for storage of plasma-activated water.

[0043] The proposed device for producing plasma-activated water preferably comprises an activation chamber for accommodating a volume of water, a plasma source for generating an atmospheric plasma in a working gas, wherein the plasma source has a nozzle opening from which the working gas exits during operation, and an aerator configured to direct the working gas exiting the nozzle opening during operation into the activation chamber. In particular, the aerator is configured to aerate a volume of water present in the activation chamber with the working gas exiting the nozzle opening during operation. For this purpose, the aerator preferably has one or more outlet openings in the floor region of the activation chamber, from which the working gas can enter a volume of water present in the activation chamber.Preferably, the aerator is designed as a disc aerator having a gas-permeable membrane bordering the activation chamber, so that the working gas emerging from the nozzle opening during operation passes through the membrane of the disc aerator into the activation chamber.

[0044] In a further embodiment, the device for producing plasma-activated water has an inlet for introducing water into the activation chamber and an outlet separate from the inlet for discharging water from the activation chamber. This also allows, for example, continuous operation of the device, so that, for example, fresh water can be continuously introduced into the activation chamber through the inlet and activated water can be discharged from the activation chamber through the outlet and fed, for example, for immediate use, such as the actuating means of a bottling plant.

[0045] In a further embodiment, the plasma source of the device for producing plasma-activated water is configured to generate a plasma by generating electrical discharges in a working gas, preferably by means of dielectrically impeded discharges between two electrodes. It has been found that the generation of an atmospheric plasma by means of dielectrically impeded discharge is particularly suitable for the production of plasma-activated water. Plasma-activated water produced in this way exhibited a stronger antibacterial effect in tests than plasma-activated water produced using a different type of plasma source, for example, a plasma source in which the plasma is generated by means of high-frequency arc-like discharges in a working gas.

[0046] The above-mentioned object can further be achieved by a method for disinfecting a surface, in which the surface to be disinfected is exposed to a cleaning liquid, in which an atmospheric plasma is generated in a plasma source in a working gas which emerges from a nozzle opening of the plasma source, and in which the surface exposed to the cleaning liquid is exposed to the working gas emerging from the plasma source.

[0047] It has been found that, compared to simply exposing a surface to be disinfected to a cleaning fluid, such as an aqueous hydrogen peroxide solution, a comparable disinfection effect can be achieved by subsequently exposing the surface exposed to the cleaning fluid to a working gas emitted from a plasma nozzle, even at lower concentrations of reactive substances in the cleaning fluid. For example, in experiments, a 7% aqueous hydrogen peroxide solution subsequently exposed to a plasma jet achieved a comparable disinfection effect to an aqueous 30% hydrogen peroxide solution without the corresponding exposure to a plasma jet.

[0048] In this process, the surface exposed to the cleaning fluid is exposed to the working gas emitted from the plasma source. The working gas is thus applied while the surface to be disinfected is still covered with a corresponding film of cleaning fluid. This results in the plasma generating reactive species in the exposed cleaning fluid, which lead to a stronger disinfection effect of the cleaning fluid and thus allow for effective disinfection even at lower concentrations of, for example, hydrogen peroxide in the original cleaning fluid.

[0049] The cleaning fluid used can be, for example, water or a water-containing solution, in particular an aqueous hydrogen peroxide solution. The cleaning fluid preferably has a hydrogen peroxide concentration in the range of 1-10 wt.%; in particular, it has been found that the hydrogen peroxide concentration can be much lower than the 30 wt.% commonly used for disinfection.

[0050] The method described above can preferably be used for disinfecting components of a filling plant and / or materials used in the operation of the filling plant, wherein the components to be disinfected and / or the materials to be disinfected are exposed to the cleaning liquid and wherein the components and / or materials exposed to the cleaning liquid are exposed to the working gas emerging from the plasma source.

[0051] According to the invention, the above-mentioned object is achieved according to the second aspect according to claim 6 by a method for disinfecting components of a filling plant and / or materials used in the operation of the filling plant, in which the components to be disinfected and / or the materials to be disinfected are exposed to a cleaning liquid, in which an atmospheric plasma is generated in a plasma source in a working gas which emerges from a nozzle opening of the plasma source, and in which the components exposed to the cleaning liquid and / or the materials exposed to the cleaning liquid are exposed to the working gas emerging from the plasma source, wherein an aqueous hydrogen peroxide solution with a hydrogen peroxide concentration in the range of 1 to 10 wt.% is used as the cleaning liquid.

[0052] The plasma source is preferably configured to generate the atmospheric plasma by means of a dielectrically impeded discharge. It has been found that a plasma generated in this way leads to higher hydrogen peroxide concentrations in the water film of cleaning fluid applied to the surface to be disinfected, so that a particularly good disinfection effect can be achieved. In particular, the plasma source can be designed and / or operated like the plasma source described for the first aspect.

[0053] In particular, the plasma source can have two electrodes with a discharge space arranged between them, wherein at least one of the electrodes is insulated from the discharge space by a dielectric, for example a ceramic. Furthermore, a power supply is preferably provided, which is configured to apply a high-frequency high voltage to the electrodes. During operation, the two electrodes are subjected to a high-frequency high voltage via the power supply. Since the dielectric prevents direct discharges between the electrodes, so-called dielectrically impeded discharges, also referred to as dielectric barrier discharges, occur in the discharge space.

[0054] The high-frequency high voltage for operating the plasma source preferably has a voltage amplitude in the range of 1 kV to 40 kV, preferably 5 kV to 20 kV, at a frequency in the range of 10 kHz to 40 kHz, preferably 12 kHz to 18 kHz. It has been found that operating the plasma source at a frequency in the range of 12 kHz to 18 kHz generates a particularly high amount of ozone, which allows for a particularly effective disinfection effect.

[0055] The high-frequency high voltage required to operate the plasma source is the voltage present between the electrodes during operation. For example, when using a transformer to operate the plasma source, this voltage is the secondary voltage.

[0056] The working gas flowing through the previously described plasma source during operation comes into contact with the dielectrically impeded discharges occurring in the discharge chamber and is thereby at least partially converted into the plasma state, generating an atmospheric plasma. The plasma generation creates reactive species in the working gas, such as ozone or nitrogen oxides, which remain at least partially present in the working gas even after recombination. The working gas exiting the nozzle opening of the plasma source therefore contains reactive species, even if the components of the working gas ionized in the discharge chamber have already recombined, so that the working gas is no longer in the plasma state at the nozzle opening.

[0057] Air is the preferred working gas. In addition to being readily available, this also results in a particularly effective disinfection effect.

[0058] The filling system can have a housing that defines an at least partially enclosed space in which the components and / or materials to be disinfected are arranged. For example, the filling device of the filling system and / or any cleaning device provided can be accommodated in a housing. The application means are preferably configured to apply the cleaning fluid to the components and / or materials to be disinfected within the housing, and the plasma source is preferably configured to distribute the working gas emerging from the nozzle opening during operation into the space defined by the housing. In particular, multiple plasma sources can also be provided to distribute the working gas emerging from the plasma sources into the space defined by the housing.In a corresponding embodiment of the method, the working gas is introduced from the nozzle opening into an at least partially enclosed space containing the components and / or materials to be disinfected. In this way, disinfection of an entire section of a filling system located within the enclosure or the space defined by it can be achieved.

[0059] The features previously described for the first aspect of the disclosure can also be combined with the second aspect of the disclosure. Accordingly, the features described for the second aspect of the disclosure can also be combined with the first aspect of the disclosure.

[0060] Further advantages and features of the present invention will become apparent from the following description of exemplary embodiments, with reference to the accompanying drawings.

[0061] In the drawing show Fig. 1 shows a plasma source for generating an atmospheric plasma, Fig. 2 shows an embodiment of the device for producing plasma-activated water, Fig. 3 shows an embodiment of the method according to the first aspect of the present invention, Fig. 4 shows an embodiment of the method according to the second aspect of the present invention, Fig. 5 shows an embodiment of a filling system according to the invention, Fig. 6 shows a section of the filling system from Fig. 5 , Fig. 7 shows a further embodiment of a filling system according to the invention, Fig. 8 shows a further plasma source for generating an atmospheric plasma, Fig. 9 shows another embodiment of the plasma source from Fig. 1 , Fig. 10 an example of another method and Fig. 11 a diagram with test results.

[0062] Figure 1shows a plasma source for generating an atmospheric plasma. The plasma source 2 comprises a metal nozzle tube 4, which tapers conically at one end to a nozzle opening 6. A gas inlet 8 for a working gas is provided at the end of the nozzle tube 4 opposite the nozzle opening 6. A ceramic tube 10 is arranged in the nozzle tube 4 such that an annular channel 12 is formed between the ceramic tube 10 and the nozzle tube 4, through which the working gas can flow from the gas inlet 8 to the nozzle opening 6.

[0063] A cylindrical inner electrode 14 is arranged on the inside of the ceramic tube 10 and is connected to a high-voltage source 18 via a high-voltage cable 16. The nozzle tube 4 is grounded and thus represents an outer electrode.

[0064] During operation, a working gas, preferably air, is introduced into the plasma source 2 through the gas inlet 8 from a working gas source (not shown). Furthermore, a high-frequency high voltage is applied between the inner electrode 14 and the nozzle tube 4, which acts as the outer electrode, by means of the high-voltage supply 18. Since the ceramic tube 10 electrically insulates the inner electrode 14 from the outer electrode 4, no direct discharge arcs can occur between the inner and outer electrodes. Instead, so-called dielectrically impeded discharges occur, in which electrical discharges occur in the discharge space 20 between the inner and outer electrodes.

[0065] The discharges in the discharge chamber 20 at least partially convert the working gas flowing through the channel 12 into a plasma state, thus generating an atmospheric plasma. The working gas then exits the plasma nozzle 2 as the working gas stream 22 through the nozzle opening 6.

[0066] The working gas 22 exiting the plasma nozzle 2 may still be partially in the plasma state when exiting the nozzle opening 6. However, it is also conceivable that the working gas 22 is completely recombined by the time it reaches the nozzle opening 6, so that the working gas 22 is no longer in the plasma state.

[0067] However, due to the excitation of the working gas in the discharge zone 20, the working gas emerging from the plasma nozzle 2 contains reactive species, in particular ozone and / or nitrogen oxides.

[0068] Figure 2shows a first embodiment of the device for producing plasma-activated water in a schematic sectional view.

[0069] The device 40 comprises a container 42 in the form of a glass cylinder surrounding an activation chamber 44 for accommodating a water volume 46. Instead of a glass cylinder, containers of other shapes can also be used. Furthermore, the container can also be made of plastic, preferably PVC, or metal, for example. A disc aerator 48 is provided at the bottom of the container, which has a supply line 50 for a working gas and a membrane 52 that forms the bottom of the activation chamber 44 and thus borders the activation chamber 44.

[0070] The plasma source 2 is connected to the supply line 50 Figure 1connected in such a way that the working gas 22 emerging from the plasma source 2 is introduced into the plate aerator 48 via the supply line 50. The gas-permeable membrane 52 has a plurality, in particular thousands, of small openings (in the schematic Fig. 2 The openings are exaggeratedly large.) through which the working gas from the plasma source 2 enters the water volume 46 in the form of small bubbles. In this way, the water volume 46 located in the activation chamber 44 comes into intimate contact with the working gas stream 22 from the plasma source 2, so that the active species in the working gas 22, in particular ozone and nitrogen oxides, form long-lived reactive species, in particular hydrogen peroxide, nitrous acid, or nitric acid, in the water volume 46. In this way, the plasma-activated water can be produced.

[0071] In order to be able to extract the portion of the working gas that is not dissolved in the water 46 in a controlled manner, the container 42 has a lid 56 with an extraction nozzle 58, to which a suction device (not shown) is connected. Furthermore, the device 40 has an inlet 60 for introducing water into the activation chamber 44 and a separate outlet 62 for discharging the plasma-activated water from the activation chamber. This also enables continuous operation of the device 40. Alternatively, the device 40 can also be operated in batches.

[0072] The supply line 50 is in Fig. 2 It is designed with a T-piece, so that in addition to the working gas 22, another gas can optionally be fed into the disc aerator 48, which can influence the concentration of the reactive species in the plasma-activated water. Of course, a design without a T-piece is also conceivable.

[0073] Figure 3 shows a schematic representation of an embodiment of the method for disinfecting components of a filling plant and / or materials used in the operation of the filling plant according to the first aspect.

[0074] In the process, plasma-activated water 70 is mixed with the Figure 2 The device described is produced by generating an atmospheric plasma in a working gas using the plasma source 2 and passing the working gas 22 emerging from the plasma source through the plate aerator 48 into the water 46 contained in the container 42, so that long-lived reactive species accumulate in the water 46.

[0075] The plasma-activated water 70 produced in this way is then directed from the device 40 to a nebulizing nozzle 72, where it is nebulized. For this purpose, the nebulizing nozzle has a first inlet 74 for supplying the plasma-activated water 70 and a second inlet 76 for supplying a nebulizing gas. At the nozzle outlet 78 of the nebulizing nozzle 72, the nebulizing gas nebulizes the plasma-activated water 70, forming a mist 80 of plasma-activated water. The nebulizing nozzle 72 is directed toward the component of the filling system to be disinfected, or toward the materials used in the operation of the filling system, so that their surface 82 is wetted by the mist 80 of the plasma-activated water. The reactive species in the plasma-activated water 70 thus disinfect the surface 82.

[0076] Figure 4shows a schematic representation of an embodiment of the method for disinfecting surfaces according to the second aspect.

[0077] In the method, a surface 100 to be disinfected is first exposed to a cleaning liquid 102, for example water or 3-7% aqueous hydrogen peroxide solution, for example by introducing the cleaning liquid 102 and a nebulizing gas 106, in particular air, into a nebulizing nozzle 104, so that a mist 110 of the cleaning liquid 102 emerges from the nozzle opening 108 of the nebulizing nozzle 104 and wets the surface 100 to be disinfected.

[0078] Then the plasma source 2 from Fig. 1An atmospheric plasma is generated, and the working gas 22 exiting the nozzle opening 6 of the plasma nozzle is directed onto the surface 100 to be disinfected, which has previously been wetted with the cleaning liquid 102. The interaction of the working gas 22 from the plasma source 2 with the cleaning liquid film on the surface 100 results in an enhanced disinfection effect of the cleaning liquid 102, so that despite a relatively low concentration of, for example, hydrogen peroxide in the cleaning liquid, a strong disinfection effect can be achieved, for which a much higher hydrogen peroxide concentration would be required without the subsequent treatment with the working gas 22.

[0079] The Figure 5shows an embodiment of a filling system according to the invention in a highly schematic top view. The filling system 120 is a beverage filling system for bottling beverages. The filling system has a transport system 122 with which the bottles are transported from a bottle supply 124 through the individual stations of the filling system 120. In a first station 126, the bottles are aligned and separated so that they can be transported through the system at regular intervals by the transport system 120.

[0080] In the second station 128, the bottles are cleaned internally and externally, filled with the beverage, and sealed with a lid. In a further station 130, the bottles are then labeled and packed into containers at a final station 132, ready for further transport on pallets 134 for distribution.

[0081] Figure 6 shows a schematic representation of station 128 from a top view. The bottles are first guided by the transport system 122 to a cleaning device 136, where the bottles are cleaned inside and out. For this purpose, the bottles are transferred to a cleaning carousel 138, in which the bottles are transported on a circular path while being cleaned inside and out using cleaning agents provided for this purpose in the form of nozzles 140 and injector nozzles 142.

[0082] After passing through the cleaning carousel 138, the bottles are transferred via conveyor circuits to a rinsing carousel 144, where the bottles are again circulated while being cleaned of any remaining cleaning fluid from the previous cleaning by being sprayed with water. The bottles are then forwarded to a filling carousel 146, where the bottles are again circulated and filled with a beverage through rotating outlet nozzles and sealed with a cap.

[0083] The bottles are then transported to the next station 130 by the transport system 122.

[0084] For hygiene reasons, station 128 must be disinfected regularly, or even permanently if necessary. For this purpose, cleaning nozzles 150 are provided throughout the station, which can be used to spray the individual components of station 128 with a cleaning fluid.

[0085] In the prior art, a high-percentage aqueous hydrogen peroxide solution, such as 30%, was regularly used to disinfect the system. However, this requires the storage of large quantities of hydrogen peroxide.

[0086] At the Figure 5 and 6 However, in the filling plant shown, the nozzles 150 are connected to a device for producing plasma-activated water, for example the device 40 of Figure 2 To disinfect the components of station 128 of filling system 120, plasma-activated water is then sprayed onto the individual components using nozzles 150, thereby achieving thorough disinfection of the components without the need to store large quantities of hydrogen peroxide.

[0087] Furthermore, the plasma-activated water can also be used to clean the bottles, for example, by spraying the plasma-activated water onto the outer surface of the bottles via the nozzles 140. It is also conceivable to disinfect the interior of the bottles with plasma-activated water by spraying the plasma-activated water into the bottles via the injector nozzle 142. Alternatively, working gas escaping from a plasma source can be introduced into the bottles.

[0088] By using the plasma-activated water to disinfect components of the filling system 120 or materials in the form of bottles used in the operation of the filling system 120, effective disinfection and safe operation of the filling system 120 can be ensured.

[0089] In an alternative embodiment of the filling system according to the second aspect, the components of the filling system 120 can also be first exposed to a cleaning fluid, for example, water or a 3% aqueous hydrogen peroxide solution, via the nozzles 150, and then to a working gas emerging from a plasma source. For this purpose, a housing 160 is preferably provided around the station 128, as well as several plasma nozzles, with which the working gas emerging from the plasma nozzles can be distributed in the interior 162 of the housing (see FIG. Fig. 5 ). The interaction of the cleaning fluid film on the components to be disinfected with the working gas from the plasma nozzles enhances the disinfection effect of the cleaning fluid, so that the desired disinfection effect can be achieved even at lower hydrogen peroxide concentrations in the cleaning fluid.

[0090] Figure 7 shows a further embodiment of a filling system 180. The filling system 180 is designed as a beverage filling system for filling milk into hoses 182.

[0091] During operation of the filling system 180, a continuous tube 184 is taken from a tube supply 186 and cut into tube sections of a predetermined length at a cutting device 188. The tube sections are then fed to a cleaning device 190, in which a cleaning fluid is sprayed from a reservoir 192 onto the outside of the tube sections via nozzles 194. The tube sections are then guided to a filling station 196, welded on one side by an ultrasonic welder 200, filled with milk via a provided outlet nozzle 198, and then completely welded by the ultrasonic welder 200. The tubes are then led out of the filling system 180 through a sterile area 202.

[0092] In an embodiment according to the first aspect, plasma-activated water, which is stored in the reservoir 192, is used as the cleaning fluid for cleaning the hose sections in the cleaning device 190. Alternatively, instead of the reservoir 192, for example, the device 40 for producing plasma-activated water from Figure 1 be connected.

[0093] For disinfection of the individual components of the filling system 180 itself, nozzles 204 can be provided in the system, which spray plasma-activated water at certain intervals or continuously onto the components of the system and thereby disinfect them.

[0094] In an alternative embodiment according to the second aspect, the components of the filling system 180 are exposed to a cleaning fluid, for example, a 3% aqueous hydrogen peroxide solution, via the nozzles 204. Subsequently, a plasma or a working gas emerging from the plasma nozzles 210 is introduced into the interior 206 of the housing 208 surrounding the filling system 180 via several provided plasma nozzles 210, and the interior 206 is thereby flooded, so that the components of the filling system 180 previously exposed to the cleaning fluid are more intensively disinfected.

[0095] As the examples from the Figures 6 and 7 As shown, the teaching of the invention can be applied to various types of filling systems. In particular, plasma-activated water can be used to disinfect various types of filling systems.

[0096] Fig. 8shows a schematic sectional view of another plasma source 226 for generating an atmospheric plasma in the form of a plasma nozzle. The plasma nozzle 226 has a metal nozzle tube 228 that tapers substantially conically to a nozzle tube orifice 230. At the end opposite the nozzle tube orifice 230, the nozzle tube 228 has a swirl device 232 with an inlet 234 for a working gas, for example, air.

[0097] An intermediate wall 236 of the swirl device 232 has a ring of circumferentially inclined bores 238 through which the working gas is swirled. The downstream, conically tapered portion of the nozzle tube 228 is therefore flowed through by the working gas in the form of a vortex 240, the core of which extends along the longitudinal axis of the nozzle tube 228. An electrode 242 is arranged centrally on the underside of the intermediate wall 36 and projects coaxially into the nozzle tube 228 in the direction of the tapered section. The electrode 242 is electrically connected to the intermediate wall 236 and the remaining parts of the swirl device 232. The swirl device 232 is electrically insulated from the nozzle tube 228 by a ceramic tube 244. A high-frequency high voltage generated by a transformer 246 is applied to the electrode 242 via the swirl device 232.The inlet 234 is connected to a pressurized working gas source with a variable flow rate via a hose (not shown). The nozzle tube 228 is grounded. The excited voltage generates a high-frequency discharge in the form of an arc 248 between the electrode 242 and the nozzle tube 228.

[0098] The terms "arc," "arc discharge," and "arc-like discharge" are used here as phenomenological descriptions of the discharge, since the discharge occurs in the form of an arc. The term "arc" is also used elsewhere to describe the discharge form for DC discharges with essentially constant voltage values. In this case, however, it is a high-frequency discharge in the form of an arc, i.e., a high-frequency arc-like discharge.

[0099] Due to the swirling flow of the working gas, this arc 248 is channeled in the vortex core on the axis of the nozzle tube 228, so that it only branches out to the wall of the nozzle tube 228 in the area of the nozzle tube orifice 230.

[0100] The working gas, which rotates at a high flow velocity in the region of the vortex core and thus in the immediate vicinity of the arc 248, comes into intimate contact with the arc 248 and is thereby partially converted into the plasma state, so that an atmospheric plasma jet 250 passes through the nozzle tube mouth 230 into an outlet nozzle 252 adjacent to the nozzle tube mouth.

[0101] The working gas then exits the plasma nozzle 226 in the form of the plasma jet 250 from the nozzle opening 254 of the outlet nozzle 252.

[0102] Fig. 9 shows another design of the plasma source from Fig. 1. The structure of the plasma source 2' essentially corresponds to the structure of the plasma source 2 from Fig. 1 . Identical components are provided with the same reference numerals. In addition, the plasma source 2' has a device 270 with which a cleaning liquid can be introduced into the working gas 22 exiting the plasma source 2'. The device 270 can, for example, be an evaporator configured to evaporate a cleaning liquid 272 and introduce it into the working gas 22. Alternatively, the device 270 can also be an atomizer or nebulizer configured to atomize or nebulize a cleaning liquid 272 and introduce it into the working gas 22. Furthermore, the device 270 can also be configured to spray a cleaning liquid 272 into the working gas 22.

[0103] The cleaning fluid 272 may in particular be water, an aqueous hydrogen peroxide solution or plasma-activated water.

[0104] The device 270 is connected to a source 274 for the cleaning fluid. The source 274 may, in particular, be a reservoir containing the cleaning fluid 272 or a device for producing plasma-activated water, such as the device 40 of Fig. 2 , act.

[0105] The device 270 can be as in Fig. 9 shown in the area of the nozzle opening 6 outside the nozzle tube 4. Alternatively, the device 270 can also be arranged as in Fig. 9 shown in dashed lines (reference numeral 270') into the nozzle tube 4 or also into a nozzle arrangement (not shown) provided on the nozzle tube 4.

[0106] Fig. 10shows a schematic representation of an example of a process for disinfecting surfaces.

[0107] In the method, the surface 100 to be disinfected is first sprayed with the plasma jet 226 from Fig. 8 atmospheric plasma jet 250. Subsequently, the surface 100 treated in this way is sprayed with the working gas 22 from the plasma nozzle 2' Fig. 9 applied, wherein by means of the device 270 arranged in the region of the nozzle opening 6 a cleaning liquid 272 is, for example, evaporated, nebulized, atomized or sprayed and introduced into the working gas 22, so that the cleaning liquid 272 and the working gas 22 reach the surface 100 together.

[0108] The surface 100 may, for example, be the surface of a component of a filling system, such as the filling system 120 or 180, or of materials used in the operation of the filling system.

[0109] It has been shown that surfaces with the Fig. 10 The methods described can be disinfected more effectively and at higher travel speeds of the plasma sources 226 and 2'.

[0110] Within the scope of the invention, series of tests were carried out with a device as in Fig. 2 presented to demonstrate the enrichment of reactive species in water by treatment with working gas from a plasma source and thus the producibility of plasma-activated water.

[0111] For each of the individual experiments in the test series, a test volume of 2 l of either a 0.9% aqueous NaCl solution or a phosphorus-buffered aqueous saline solution (PBS) was added to vessel 42 and exposed to the working gas from plasma source 2 for various periods of time using the disc aerator 48. Air was used as the working gas.

[0112] Before exposure to the working gas, the test volumes were each spiked with E. coli bacteria. Before and after exposure to the water with working gas 22 from plasma source 2, samples of the water were taken and dropped in several dilution steps onto a quarter of an LB agar plate. The samples were incubated for 3 days at 30°C. After three days, the colonies were counted.

[0113] The results of the tests are in Fig. 11 presented in the form of a diagram: In the diagram in Fig. 11The bars show the reduction in colony-forming units (CFU) per milliliter in log10 steps, for the NaCl solution (left bar in each case) and for the PBS solution (right bar in each case). As the diagram shows, a significant reduction in colony-forming units by approximately seven log10 steps was achieved after just 2 minutes of water treatment. This confirms that exposure of the water to the working gas 22 from plasma source 2 leads to an enrichment of reactive species in the water that have a strong disinfecting effect. The plasma-activated water produced in this way is therefore particularly suitable for disinfection.

[0114] Furthermore, experiments were carried out which demonstrate the effectiveness of the procedure according to the second aspect.

[0115] For this purpose, 21 commercially available and similar beverage bottle caps made of polyethylene (PE) were contaminated by dripping 20 µl of a test microbial solution (Bacillus atrophaeus spores 9372) onto each cap. After contamination, the caps were dried for 30 minutes at 30 °C.

[0116] Of the 21 contaminated screw caps, three were not treated as control samples. The other 18 contaminated screw caps were sprayed with demineralized water (DI water) or an aqueous hydrogen peroxide solution (3 wt.%, 7 wt.%, or 10 wt.%) using an atomizer. A portion of the sprayed screw caps were additionally exposed to working gas from a plasma source for 30 s. For this purpose, a plasma nozzle with the Fig. 1 shown structure is used.

[0117] After treatment, all lids were incubated for 5 minutes each and then rinsed with 1 ml of 0.9% NaCl solution. For each sample, a logarithmic dilution series with eight dilution levels (10 -1< to 10 -8<) was prepared using the wash solution obtained from this rinse. 100 µl of each of the eight dilution levels per sample was added dropwise to one-quarter of an LB agar plate. The samples were incubated for 3 days at 30°C. After three days, the colonies were counted.

[0118] The following Table 1 shows the results of this series of tests. The first column shows the treatment of the lids for each sample. The third to tenth columns show the number of colony forming units (CFU) on the LB agar plate for the individual dilution levels 10 -1< (1:10) to 10 -8< (1:10 8< ). The eleventh column shows the bacterial concentration per milliliter of wash solution calculated from the results for the dilution levels in the base logarithm. The value of 7.4 for the first control sample therefore corresponds to a bacterial concentration in the original wash solution of this sample of 10 7.4< . The twelfth column shows the reference value of 7.6 for the log bacterial concentration calculated by averaging for the three control samples. For the remaining samples, the twelfth column shows the reduction in the respective log bacterial concentration from column 11 compared to the reference value of 7.6 for the control samples.A log reduction of 2.8 for the first sample treated with deionized water and plasma corresponds to a reduction of the bacterial concentration in the corresponding wash solution by a factor of 10 2.8< (approx. 631).

[0119] The results show that applying a cleaning fluid to the lids in combination with plasma (or the working gas from the plasma source) leads to a significantly greater reduction in colony-forming units than the cleaning fluid alone. In particular, good disinfection results were achieved even at low hydrogen peroxide concentrations or even with pure water.

[0120] In particular, the results demonstrate the advantageous combination of exposure to hydrogen peroxide solution and plasma (or working gas from a plasma source). Even at a relatively low hydrogen peroxide concentration of 3 wt.%, the combination with plasma or working gas exposure from a plasma source achieved a very good bacterial reduction of at least 7.6 log reductions, whereas exposure to demineralized (DI) water and plasma only led to lower log reductions in some cases. However, the log reduction achieved with the combination of demineralized water and plasma was still significantly better than the virtually nonexistent log reduction when exposed to, for example, a 10% hydrogen peroxide solution without subsequent plasma or working gas treatment. Table 1 Treatment Sample No. / sample no. CFU / 100µl 10 -1< CFU / 100µl 10 -2< CFU / 100µl 10 -3< CFU / 100µl 10 -4< CFU / 100µl 10 -5< CFU / 100µl 10 -6< CFU / 100µl 10 -7< CFU / 100µl 10 -8< log Log reduction control 1 >200 >200 47 4 1 - - - 7,4 7,6 2 >200 >200 50 6 2 - - - 7,6 3 >200 >200 60 16 - - - - 7,7 Demineralized water with plasma 1 15 - - - - - - - 4,8 2,8 2 6 - - - - - - - 4,4 3,2 3 - - - - - - - - 0 7,6 3% H2O2 1 >200 >200 103 26 3 - - - 8 0 2 >200 >200 106 20 3 - - - 7,9 0 3% H2O2 with plasma 1 - - - - - - - - 0 7,6 2 - - - - - - - - 0 7,6 3 - - - - - - - - 0 7,6 7% H2O2 1 >200 >200 102 20 2 - - 8,1 0 2 >200 >200 133 35 3 - - - 8 0 7% H2O2 with plasma 1 - - - - - - - - 0 7,6 2 - - - - - - - - 0 7,6 3 - - - - - - - - 0 7,6 10% H2O2 1 >200 >200 122 25 4 - - - 8 0 2 >200 >200 99 26 4 - - - 8 0 10% H2O2 with plasma 1 - - - - - - - - 0 7,6 2 - - - - - - - - 0 7,6 3 - - - - - - - - 0 7,6

[0121] Furthermore, tests were carried out to determine the effect of the procedure Fig. 10 prove.

[0122] The experiments used a commercially available test system consisting of bioindicator spore strips containing Geobacillus stearothermophilus 7953 spores and a specified nutrient solution. Specifically, the product used was MesaStrip(R) Log6, available from Mesa Laboratories, Inc., Lakewood, CO, USA. Geobacillus stearothermophilus are very robust spores that can withstand high temperatures and other adverse environmental conditions quite well.

[0123] A first group of spore strips was not treated (control group). A second group of spore strips was treated only with the working gas from the Fig. 8plasma nozzle 226 shown (group "Nozzle 1"). A third group of spore strips was treated only with the working gas from the Fig. 9 The plasma source 2' shown in Figure 1 was used as the cleaning fluid 272 (group "Nozzle 2"). A fourth group of spore strips was finally treated according to the procedure from Fig. 10 treated, ie with both plasma sources 226 and 2', where as cleaning fluid for the Fig. 9 The plasma source 2' of water shown was used (group "Nozzles 1+2"). The spore strips were then placed in the specified nutrient solution according to the manufacturer's test instructions.

[0124] The test system is prepared by the manufacturer in such a way that a color reaction can be used to determine whether the previous treatment of the spore strips has resulted in a reduction of the germs by 6 log levels (ie by a factor of 10 6< ).

[0125] The results of the tests are summarized in Table 2 below: Table 2 Spore stripe group Reduction of 6 log levels achieved? 1 Control group No 2 Group "Nozzle 1" No 3 Group "Nozzle 2" No 4 Group "Nozzles 1+2" Yes

[0126] As can be seen from Table 2, the reduction of 6 log levels was only achieved in the samples treated with the Fig. 10 Treatment with the plasma beam alone from the method described in Fig. 8 plasma nozzle shown or a treatment solely by the working gas from the Fig. 9 The plasma source shown with water added as a cleaning fluid did not result in a reduction of 6 log levels.

[0127] The experiments show that the Fig. 10 The method described is particularly suitable for disinfection in the presence of very robust germs.

Claims

1. Method for the disinfection of components of a filling machine (120, 180), - in which the components to be disinfected are exposed to plasma-activated water (70), the plasma-activated water (70) being vaporised, sprayed and / or atomised for exposure to the components to be disinfected.

2. Method according to claim 1, characterised in that the plasma-activated water (70) is or has been is produced by a method for the production of plasma-activated water (70) - in which, in a discharge chamber (20) of a plasma source (2), an atmospheric plasma is generated in a working gas, preferably by means of a dielectric barrier discharge, and - in which the working gas (22) is introduced from the discharge chamber (20) via a disc diffuser (48) into a water volume (46).

3. Filling machine, configured for filling a product into containers, - with exposure means (72, 150, 194) for exposing components of the filling machine (120, 180) to a cleaning liquid - wherein the exposure means are configured to expose the components to plasma-activated water (70), and - where the exposure means (72, 150, 194) comprise - one or more nozzles configured to spray plasma-activated water onto the components to be disinfected, and / or - one or more vaporisers configured to vaporise plasma-activated water in the area of the components to be disinfected, and / or - one or more atomisers configured to atomise plasma-activated water in the area of the components to be disinfected, characterised - in that the exposure means (72, 150, 194) are connected to a reservoir containing plasma-activated water (70), or - in that the exposure means (72, 150, 194) are connected to a device (40) for producing plasma-activated water (70).

4. Filling machine according to claim 3, characterised in that a device (40) for producing plasma-activated water (70) is provided and in that the exposure means (72, 150, 194) are connected to the device (40) for producing plasma-activated water (70) in such a way that plasma-activated water (70) produced by the device (40) for producing plasma-activated water (70) is conducted to the exposure means (72, 150, 194).

5. Filling machine according to claim 4, characterised in that the device (40) has an activation chamber (44) for receiving a volume of water (46), a disc diffusor (48) which has a gas-permeable membrane (52) adjoining the activation chamber (44), and a plasma source (2) for generating an atmospheric plasma in a working gas, wherein the plasma source (2) has a nozzle opening (6), from which the working gas (22) emerges during operation, and wherein the plasma source (2) is connected to the disc diffusor (48) in such a way that the working gas (22) emerging from the nozzle opening (6) during operation passes through the membrane (52) of the disc diffusor (48) into the activation chamber (44).

6. Method for disinfecting components of a filling machine (120, 180) and / or materials used in the operation of the filling machine (120, 180), - in which the components to be disinfected and / or the materials to be disinfected are exposed to a cleaning liquid (102), - in which, in a plasma source (2), an atmospheric plasma is generated in a working gas, in particular by means of dielectric barrier discharge, which working gas emerges from a nozzle opening (6) of the plasma source (2), and - in which the components and / or materials exposed to the cleaning liquid (102) are exposed to the working gas (22) emerging from the plasma source (2), characterised in that an aqueous hydrogen peroxide solution with a hydrogen peroxide concentration in the range from 1 to 10 wt.% is used as the cleaning liquid (102).

7. Method according to claim 6, characterised in that the working gas (22) is introduced from the nozzle opening (6) into an at least partially closed space (162, 206) in which the components and / or materials to be disinfected are located.