DE102023136302A1 - Method and device for cleaning laundry and method and device for producing plasma-activated liquid - Google Patents

Abstract

According to a first aspect, the invention relates to a method for cleaning laundry, in particular flat laundry, in which one or more items of laundry (104, 204) are exposed to plasma-activated water (124, 224, 536) by spraying the plasma-activated water (124, 224, 536) onto the one or more items of laundry (124, 224, 536) by means of at least one spraying device (122, 222), and to a suitable device (100, 200) therefor. Furthermore, according to a second aspect, the invention relates to a method for producing plasma-activated liquid (124, 224, 536), in particular plasma-activated water, in which a reactive gas stream (504) is generated, in particular an atmospheric plasma jet, in which a first spatial region (514) is flowed through by the reactive gas stream (504) and in which a second spatial region (516) is flowed through by a liquid (531), in particular water, wherein the first spatial region (514) and the second spatial region (516) are arranged adjacent to one another and separated from one another by a membrane (518) which is permeable to reactive species (520) from the first spatial region (514) and impermeable to liquid (531) from the second spatial region (516), and to a suitable device (500) therefor.

Description

The present disclosure relates, according to a first aspect, to a method and apparatus for cleaning laundry. The present disclosure further relates, according to a second aspect, to a method and apparatus for producing plasma-activated liquid.

From the WO 2014/090755 A1 A washing machine is known in which a plasma nozzle is integrated, with which water supplied to a washing drum can be plasma-activated.

Plasma activation of water in a washing machine requires quite high energy levels to operate the plasma nozzle to introduce sufficient reactive species into the water used in the washing machine. This leads to quite high operating costs, especially for large washing machines such as those used in industrial laundries. Furthermore, at least one plasma nozzle is required per washing machine in use, which requires quite high investment costs for industrial laundries with a large number of washing machines.

Furthermore, the doctrine of WO 2014/090755 A1 Not suitable for cleaning laundry that is not cleaned in a washing machine, but rather in a continuous cycle.

Against this background, the present disclosure is based, according to a first aspect, on the object of providing a device and a method for more efficient cleaning of laundry, which can be used, for example, in large-scale laundries.

From the WO 2021/223986 A1 A method and apparatus for producing plasma-activated water are known, in which a reactive gas is introduced into a volume of water so that the concentration of reactive species in the water volume increases over time. This method and apparatus are particularly suitable for batch operation, in which a quantity of plasma-activated water is pre-produced for later use.

Against this background, the present disclosure is based, according to a second aspect, on the object of providing an apparatus and a method for producing plasma-activated water which is better suited for continuous operation.

The aforementioned object according to the first aspect is achieved according to a first teaching of the first aspect of the present disclosure by a method for cleaning laundry, in particular flat laundry, in which one or more items of laundry are exposed to plasma-activated water by spraying the plasma-activated water onto the one or more items of laundry by means of at least one spraying device.

It has been found that laundry items can also be effectively cleaned by spraying them with plasma-activated water. In particular, it was discovered that the water sprayed onto the laundry items also has a deodorizing and disinfecting effect. Compared to the generation and use of plasma-activated water in a washing machine, this process has the advantage that significantly smaller quantities of plasma-activated water are required. This saves operating costs and, at the same time, allows for a higher enrichment of reactive species in the plasma-activated water if necessary. Furthermore, the process enables inline integration of the cleaning of laundry items using plasma-activated water into a treatment line, as used in industrial laundries.

The plasma-activated water is sprayed onto one or more items of laundry using a spray device. The spray device comprises, in particular, one or more spray nozzles with which the plasma-activated water can be sprayed. The spray device can, in particular, comprise one or more nebulizing nozzles for nebulizing the plasma-activated water. This allows for a uniform, even treatment of the laundry items.

Plasma-activated water is defined as water that has been activated by the action of a reactive gas stream 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 recombined. is bound, 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, which form relatively long-lived reactive species in water, such as hydrogen peroxide, nitric acid, or nitrous acid.

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

In industrial laundries, the cleaning, deodorization, and disinfection of laundry items is usually carried out using suitable chemicals, especially chemical disinfectants such as peracetic acid. Spraying the laundry items with plasma-activated water can replace such chemicals entirely or partially. This reduces or even completely eliminates the need for storing and/or disposing of such chemicals.

Compared to chemicals, plasma-activated water is easier to store and dispose of. Furthermore, plasma-activated water can be produced on demand using a suitable device, so storage is only required in smaller quantities or can be eliminated entirely. Furthermore, the use of plasma-activated water allows for gentler treatment of laundry items, whereas the chemicals used for disinfection in the prior art are aggressive to the textile.

The plasma-activated water preferably has a pH of less than 1.8. Additionally or alternatively, the plasma-activated water preferably has an electrical conductivity of more than 15 mS. It has been found that a significantly improved disinfection effect can be achieved in this way. The pH and electrical conductivity are indicators of the concentration of reactive species in the plasma-activated water.

The plasma-activated water can also be used in combination with chemical cleaning agents, in particular chemical disinfectants. For example, the plasma-activated water can be mixed with chemical cleaning agents, in particular chemical disinfectants, such as peracetic acid. Additionally or alternatively, the laundry items can also be sprayed with both a chemical cleaning agent and plasma-activated water using appropriate spray devices. The reactive species in the plasma-activated water can increase the effectiveness of chemical cleaning agents, so that lower concentrations of the chemical cleaning agent are required. This in turn reduces the storage and/or disposal costs for the chemical cleaning agents and reduces damage to the laundry items caused by the chemical cleaning agents.

In this process, the one or more items of laundry are preferably transported along a path and sprayed with plasma-activated water during transport. This allows for cleaning of the laundry items in a continuous flow.

The aforementioned object according to the first aspect is further achieved according to a further teaching of the first aspect of the present disclosure by a device for cleaning laundry, in particular flat laundry, in particular for carrying out the previously described method according to the first aspect or an embodiment thereof, comprising a transport device for transporting a plurality of laundry items along a predetermined route through the device, wherein the transport device is configured to transport the laundry items through a treatment area of the device, a spray device configured to spray laundry items transported through the treatment area with plasma-activated water, and a source of plasma-activated water connected to the spray device to supply them with plasma-activated water. In this way, the laundry items can be treated with the plasma-activated water in a continuous inline process, for example in a large-scale laundry, in order to achieve the advantages described in connection with the previously described method.

The method can also involve selective spraying of certain areas of the laundry, for example, particularly soiled areas. For this purpose, the spraying device can be configured to spray specific sections of the laundry. For example, a detection device, such as a camera with an image processing unit, can also be provided that detects areas of the laundry items to be sprayed, for example, particularly contaminated areas, and causes the spray device to spray these areas specifically with plasma-activated water. By applying plasma-activated water to the laundry items in such a targeted manner, a targeted treatment of the laundry items can be achieved with reduced consumption of plasma-activated water.

The aforementioned object according to the second aspect is achieved according to a first teaching of the second aspect of the present disclosure by a method for producing plasma-activated liquid, in particular plasma-activated water, in which a reactive gas stream is generated, in particular an atmospheric plasma jet, in which a first spatial region is flowed through by the reactive gas stream, in which a second spatial region is flowed through by a liquid, in particular water, wherein the first spatial region and the second spatial region are arranged adjacent to one another and separated from one another by a membrane which is permeable to reactive species from the first spatial region and impermeable to liquid from the second spatial region.

The aforementioned object according to the second aspect is further achieved according to a further teaching of the second aspect of the present disclosure by a device for producing plasma-activated water, in particular for carrying out the previously described method according to the second aspect or an embodiment thereof, comprising a plasma source which is configured to generate a reactive gas stream, in particular an atmospheric plasma jet, during operation, with a first spatial region through which the reactive gas stream generated by the plasma source during operation can flow, and with a second spatial region through which a liquid, in particular water, can flow during operation, wherein the first spatial region and the second spatial region are arranged adjacent to one another and separated from one another by a membrane which is permeable to reactive species from the first spatial region and impermeable to liquid from the second spatial region.

The method and device described above according to the second aspect enable continuous production of plasma-activated liquid, in particular plasma-activated water.

The liquid can therefore be water, in particular. The water may contain additives.

The plasma source is configured to generate a reactive gas stream during operation. The plasma source preferably has an outlet from which the reactive gas stream exits during operation.

The device further comprises a first spatial region through which the reactive gas stream generated by the plasma source during operation can flow or through which it flows. For this purpose, the plasma source, in particular its outlet, is connected to the first spatial region in such a way that the reactive gas stream generated by the plasma source during operation flows through the first spatial region.

Unlike the DE 10 2020 104 261 A1 In the device described, the reactive gas stream is therefore not generated directly in the area of the membrane, but instead is generated in a separate plasma source and then passed through the first spatial area adjacent to the membrane.

The first and second spatial regions can, in particular, be accommodated in a housing in which the membrane is arranged, separating the first and second spatial regions from each other. Such a housing with a membrane is referred to herein as a reactor. In particular, the walls of the housing, together with the membrane, can surround the first and second spatial regions.

The housing can have respective inlets and outlets for the first and second spatial areas. The plasma source is connected to the inlet of the first spatial area. A water source and optionally a pump are preferably connected to the inlet of the second spatial area. During operation, the plasma-activated water exits the outlet of the second spatial area.

The inlet of the first spatial region and the inlet of the second spatial region can be arranged at opposite ends of the respective spatial regions, so that the spatial regions are flowed through by the reactive gas stream and the liquid in opposite directions.

The first and second spatial regions are arranged adjacent to one another and separated from one another by a membrane. The membrane therefore forms part of the wall of the first and second spatial regions. The membrane is permeable to reactive species from the first spatial region and impermeable to liquid, in particular water, from the second spatial region. In particular, the membrane can be a gas-permeable and liquid-impermeable membrane, so that the (gaseous) reactive species from the reactive gas stream in the first spatial region can pass into the liquid in the second spatial region, but the liquid from the second spatial region cannot pass into the first spatial region. For example, the membrane can be a dialysis membrane, as used in dialysis machines.

Various embodiments of the method and device for cleaning laundry, as well as various embodiments of the method and device for producing plasma-activated liquid, are described below. The individual embodiments apply independently of one another to the method and device for cleaning laundry, as well as to the method and device for producing plasma-activated liquid. Furthermore, the individual embodiments can be combined with one another as desired.

In one embodiment, particularly according to the first aspect, the plasma-activated water is produced by bringing a reactive gas stream, in particular a plasma jet, into contact with liquid water. The plasma-activated water is preferably produced as needed for the spray device. By producing the plasma-activated water as needed, extended storage of the plasma-activated water is unnecessary. Furthermore, freshly produced plasma-activated water is more effective at cleaning laundry items.

The plasma-activated water is preferably produced such that it has a pH value of less than 1.8 and/or an electrical conductivity of more than 15 mS. It has been found that a significantly better cleaning effect, in particular a disinfection effect, is achieved in this way. The standing time of the plasma-activated water between the production of the plasma-activated water and the spraying of the one or more laundry items is preferably less than 12 hours, more preferably less than 6 hours, in particular less than 1 hour. The produced plasma-activated water is particularly preferably used directly for spraying the one or more laundry items. In this way, a greater cleaning effect, in particular a disinfection effect, is achieved.

In one embodiment, in particular according to the first aspect, the reactive gas stream, in particular a plasma jet, is generated by means of an arc-like electrical discharge, in particular a high-frequency arc-like discharge, between electrodes in a working gas stream. In a corresponding embodiment, the plasma source is configured to generate the reactive gas stream, in particular a plasma jet, by means of an arc-like electrical discharge, in particular a high-frequency arc-like discharge, in a working gas.

In this way, a high concentration of certain reactive species can be generated in the gas stream, in particular nitrogen oxides and/or fully or partially ionized or excited atoms or molecules. Compared to dielectric barrier discharges, ozone is generated only to a small extent, thereby reducing ozone pollution. In contrast, a high-frequency arc-like discharge produces increased amounts of nitrogen oxides, particularly when air is used as the working gas. By using such a reactive gas stream to produce the plasma-activated water, the formation of nitrous acid or nitric acid in the liquid and thus a low pH value of the plasma-activated water can be achieved, thereby achieving a good cleaning and disinfection effect.

To generate the arc-like electrical discharge, at least two electrodes are provided, as well as a voltage source for applying a high-frequency high voltage to the electrodes. The high-frequency high voltage for generating a high-frequency arc-like discharge has, in particular, a voltage in the range of 1-100 kV, preferably 1-50 kV, more preferably 10-50 kV, and a frequency of 1-300 kHz, in particular 1-100 kHz, preferably 10-100 kHz, more preferably 10-50 kHz.

In one embodiment, in particular according to the first aspect, the reactive gas stream, in particular plasma jet, is generated by means of dielectric barrier discharges between electrodes in a working gas stream. In a corresponding embodiment, the plasma source is configured to to generate a reactive gas stream using dielectric barrier discharges in a working gas. Dielectric barrier discharges can generate very high concentrations of certain reactive species, particularly ozone, in the gas stream. Using such a reactive gas stream to produce plasma-activated water can induce the formation of hydroxyl radicals in the liquid, which provide a good disinfectant effect. Plasma-activated water produced in this way also has a certain bleaching effect, for example due to the hydroxyl radicals, which can be desirable for treating certain laundry items, such as white textiles.

Dielectric barrier discharges are sometimes referred to as dielectrically hindered discharges.

To generate the dielectric barrier discharges, at least two electrodes and a dielectric arranged between them can be provided, which prevents direct electrical discharges between the two electrodes. Preferably, one of the electrodes is grounded. Furthermore, a voltage source is provided, in particular, to apply a high-frequency high voltage to the electrodes, for example, with a voltage intensity in the range of 5 to 15 kV and a voltage frequency in the range of 7.5 to 25 kHz, in particular 13 to 14 kHz.

In one embodiment, particularly according to the first aspect, the reactive gas stream, in particular a plasma jet, is generated both by means of an arc-like electrical discharge, in particular a high-frequency arc-like discharge, between electrodes in a working gas stream and by means of dielectric barrier discharges between electrodes in a working gas stream. The generation by means of an arc-like electrical discharge and the generation by means of dielectric barrier discharges can occur simultaneously and/or alternately. In a corresponding embodiment, the device comprises, in addition to the plasma source, a further plasma source which is configured to generate a reactive gas stream during operation, wherein the plasma source is configured to generate the reactive gas stream by means of an arc-like discharge in a working gas, and the further plasma source is configured to generate the reactive gas stream by means of dielectric barrier discharges in a gas stream. The gas streams generated by the plasma source and the further plasma source can then be brought into contact with the water.

In this way, various reactive species, in particular hydroxyl radicals in the first operating mode and nitric acid or nitrous acid in the second operating mode, can be enriched in the liquid, thereby further improving the disinfection effect of the plasma-activated water.

In a further embodiment, in particular according to the first aspect, the plasma source has a working gas supply configured to supply the plasma source with ambient air as the working gas. Using ambient air as the working gas eliminates the need for a separate working gas supply, thereby allowing for more flexible use of the device. The working gas supply may, in particular, comprise a fan or compressor to supply the working gas to the plasma source at a predetermined pressure and/or volume flow. To prevent contamination or microbial contamination of the device, the working gas supply preferably comprises a filter, for example a fine dust filter and/or a bacteria and/or virus filter.

In one embodiment, particularly according to the first aspect, the source of plasma-activated water comprises a device for producing plasma-activated water. The device for producing plasma-activated water comprises, in particular, a plasma source for generating a reactive gas stream and a reaction device in which the gas stream generated by the plasma source during operation is brought into contact with water, thereby generating plasma-activated water. In this way, the plasma-activated water can be generated as needed, so that there are no long, preferably no, downtimes for the plasma-activated water between its generation and the spraying of the one or more items of laundry. This can improve the cleaning and/or disinfection effect.

In one embodiment, in particular according to the first aspect, the plasma-activated water is produced using the previously described method for producing plasma-activated water according to the second aspect of the present disclosure or an embodiment thereof and/or using the previously described device for producing plasma-activated water according to the second aspect of the present disclosure or an embodiment thereof. In a corresponding embodiment In one embodiment of the device, the source of plasma-activated water comprises the previously described device for producing plasma-activated water according to the second aspect or an embodiment thereof. In this way, the plasma-activated water can be produced continuously, preferably as needed, so that storage is unnecessary. In particular, long idle times of the plasma-activated water between its production and the spraying of the one or more items of laundry can be avoided. This can improve the cleaning and/or disinfection effect.

The plasma-activated water can also be produced by bubbling the reactive gas into a volume of water via a disc aerator or a porous body. Accordingly, the reaction device can comprise a disc aerator or porous body disposed in water during operation, through which the reactive plasma jet generated by the plasma source is passed during operation.

In one embodiment, particularly according to the first aspect, the one or more laundry items are placed and transported on a transport carrier, particularly a conveyor belt, and sprayed with the plasma-activated water on the transport carrier. In a corresponding embodiment of the device, the transport device comprises one or more conveyor belts. This allows for continuous inline application of the laundry items. This embodiment is particularly advantageous for flat laundry such as bed linen, table linen, or terry cloth.

In one embodiment, particularly according to the first aspect, the one or more items of laundry are hung and transported on transport supports, particularly coat hangers, arranged one behind the other and sprayed with the plasma-activated water while hanging from the transport supports. In a corresponding embodiment of the device, the transport device has one or more conveyors for conveying transport supports for items of laundry, particularly coat hangers, along a guide profile. In this way, continuous inline loading of the items of laundry is also possible. This embodiment is particularly advantageous for shaped laundry such as clothing. The one or more conveyors can, for example, comprise a driven train, for example a chain, with several drag pawls for coat hangers.

In one embodiment, particularly according to the first aspect, the one or more items of laundry are washed before being sprayed with the plasma-activated water, particularly in a washing machine, by spraying with a cleaning fluid, or by immersing them in a cleaning fluid. In a corresponding embodiment, the device comprises a washing device for washing laundry items. In this way, the laundry items are first washed and largely freed of contaminants before being post-treated with the plasma-activated water. In this way, a better final cleaning result can be achieved.

The washing device can, for example, be designed in the form of a washing machine. After washing in the washing machine, the laundry items can be transferred to the transport device manually or automatically.

Furthermore, the washing device can have a spraying device for spraying laundry items transported by the conveyor with cleaning fluid, or a dipping tank for immersing laundry items transported by the conveyor in cleaning fluid. In this way, the laundry items can be washed inline in a continuous process.

The cleaning fluid can in particular be water mixed with detergent, for example conventional detergent.

The laundry items can be washed in several steps, for example, with a pre-wash and a main wash. For this purpose, a washing device with several spray devices or dip tanks arranged one behind the other in the direction of transport of the conveyor can be provided.

In one embodiment, particularly according to the first aspect, the one or more laundry items have a residual moisture content in the range of 10-80%, preferably 15-70%, at the beginning of spraying with the plasma-activated water. It has been found that the cleaning effect, in particular the disinfection effect, is significantly increased by spraying with plasma-activated water if the laundry items have a corresponding moisture content at the beginning of spraying.

In one embodiment, in particular according to the first aspect, the one or more laundry items are moistened before being sprayed with the plasma-activated water, in particular with water or a cleaning fluid. In a corresponding embodiment of the device, the device comprises a moistening device for moistening the laundry items, in particular with water or a cleaning fluid. The moistening device is preferably arranged upstream of, in particular directly upstream of, the spraying device in the transport direction of the transport device. By moistening or providing a moistening device, the residual moisture of the laundry items for spraying with plasma-activated water can be increased, preferably to a residual moisture in the range 10-80%.

In one embodiment, particularly according to the first aspect, moisture is removed from the one or more items of laundry before being sprayed with the plasma-activated water, in particular by drying, spinning, rolling, and/or wringing. In a corresponding embodiment of the device, the transport device is configured to transport the items of laundry through an intermediate drying area of the device before the items of laundry are transported through the application area, wherein the device has a moisture removal device configured to remove moisture from the items of laundry transported by the transport device through the intermediate drying area, in particular by drying, spinning, rolling, and/or wringing. In this way, the absorption capacity of the items of laundry for the plasma-activated water is increased, so that the plasma-activated water can better penetrate the items of laundry and exert its cleaning, deodorizing, or disinfecting effect there.

Preferably, moisture is removed from the laundry items such that, at the beginning of spraying with the plasma-activated water, the laundry items have a residual moisture content in the range of 10-80%, preferably 15-70%, more preferably 30-70%, particularly preferably 30-50%. Accordingly, the moisture removal device is preferably configured to achieve a residual moisture content in the range of 10-80%, preferably 15-70%, more preferably 30-70%, particularly preferably 30-50%.

The moisture can also be removed from the laundry items in such a way that a residual moisture content of less than 50% is achieved.

Residual moisture above 70%, especially above 80%, hinders the penetration of the plasma-activated water into the laundry. The residual moisture is preferably a maximum of 80%, more preferably a maximum of 70%, and especially a maximum of 50%. A residual moisture below 30% can only be achieved with greater effort and energy, which worsens the overall energy balance of the process. In particular, mechanical means such as rollers can be used to achieve a residual moisture in the range of 30-80%, especially 30-70%, and preferably 30-50%, so that more energy-intensive thermal drying processes can be dispensed with during the intermediate drying step before spraying with plasma-activated water.

Moisture or residual moisture is defined as the weight of water in the laundry item relative to its weight. For example, a moisture or residual moisture content of 100% means that 1 kg of laundry (dry weight, climate-dry) contains an additional 1 kg of water.

Moisture is preferably removed from the one or more laundry items prior to spraying with plasma-activated water, particularly by means of the moisture removal device, if the laundry items have a residual moisture content of more than 80%, for example, due to a previous washing of the one or more laundry items. In this way, by removing the moisture, a residual moisture content can be set, preferably in the range of 10-80%, in particular 15-70%, at the beginning of the spraying with plasma-activated water.

If the one or more laundry items have a residual moisture content below 10% prior to spraying with plasma-activated water, for example, in a cupboard-dry state, the laundry items are preferably moistened, in particular with the moistening device. In this way, the moistening can achieve a residual moisture content preferably in the range of 10-80%, in particular 15-70%, at the beginning of the spraying with plasma-activated water.

The laundry items are preferably sprayed with plasma-activated water until they are completely saturated. This is defined as the complete saturation of the laundry item, above which the laundry item begins to drip. The laundry items are preferably sprayed until Humidity or residual moisture of at least 100%, preferably at least 150%, in particular at least 200%.

In one embodiment, in particular according to the first aspect, the one or more laundry items are rinsed, in particular with water, after being sprayed with the plasma-activated water. In a corresponding embodiment of the device, the transport device is configured to transport the laundry items through a rinsing area after the laundry items have been transported through the application area, wherein the device has a rinsing device configured to rinse the laundry items transported through the rinsing area by the transport device, in particular with water. In this way, reactive species and contaminants dissolved by the reactive species can be rinsed out of the laundry items.

In one embodiment, in particular according to the first aspect, moisture is removed from the one or more laundry items after spraying with the plasma-activated water, in particular by drying, spinning, rolling, and/or wringing. In a corresponding embodiment of the device, the transport device is configured to transport the laundry items through a final drying area of the device after the laundry items have been transported through the loading area and/or the optional rinsing area, wherein the device has a moisture removal device configured to remove moisture from the laundry items transported by the transport device through the final drying area, in particular by drying, spinning, rolling, and/or wringing. The final drying is preferably carried out by rolling and/or drying in order to avoid excessive creasing of the laundry items.

The laundry items can be smoothed before, during, or after final drying, for example, by applying steam, mangling, and/or ironing. In particular, the moisture removal device can be configured to additionally smooth the laundry items, particularly by means of steam, for example, in the form of a smoothing-drying tunnel.

In one embodiment, particularly according to the second aspect, the first spatial region and/or the second spatial region are tubular or hose-shaped. In this way, the reactive species from the first spatial region can pass over a long distance through the membrane into the liquid in the second spatial region, so that after passing through the spatial region, the liquid has a sufficient concentration of reactive species for a good cleaning, deodorizing, or disinfecting effect. The first and/or the second spatial region can be configured in the form of capillaries.

In one embodiment, particularly according to the second aspect, the plasma-activated liquid is temporarily stored after flowing through the second spatial region or used to act on an object. In particular, the liquid can be used immediately after flowing through the second spatial region, in particular sprayed. This enables the plasma-activated liquid to be produced as needed and without storage. Furthermore, the immediate use of freshly produced plasma-activated liquid results in a particularly high concentration of reactive species, so that the plasma-activated liquid can be highly effective for the respective purposes, for example, a good cleaning effect, a good deodorizing effect, or a good disinfecting effect.

In one embodiment, the contact time of the plasma-activated water is at least 30 s, preferably 30 - 600 s, in particular 30 - 300 s. A contact time of at least 30 s allows a good cleaning, in particular disinfecting, effect to be achieved by the plasma-activated water. Contact times of more than 300 s or even more than 600 s are typically not necessary, since the cleaning or disinfecting effect of the plasma-activated water is already achieved beforehand, so that longer contact times unnecessarily extend the process duration. The contact time is in particular the time from spraying with plasma-activated water until a subsequent process step, in particular until a rinsing or moisture removal following the spraying, for example rolling and/or drying, of the one or more items of laundry. In a corresponding embodiment of the device, the spraying device and the transport device as well as a device following the spraying device along the predetermined path, in particular a rinsing device or moisture removal device, are preferably arranged and configured such that the exposure time of the plasma-activated water, in particular from the spraying of the laundry items until it passes through the device following the spraying device, is at least 30s, preferably 30 - 600s, in particular 30 - 300s.

In one embodiment, particularly according to the second aspect, the reactive gas stream, in particular a plasma jet, is generated by means of an arc-like electrical discharge, in particular a high-frequency arc-like discharge, between electrodes in a working gas stream. In a corresponding embodiment, the plasma source is configured to generate the reactive gas stream, in particular a plasma jet, by means of an arc-like electrical discharge, in particular a high-frequency arc-like discharge, in a working gas.

In this way, a high concentration of certain reactive species can be generated in the gas stream, in particular nitrogen oxides and/or fully or partially ionized or excited atoms or molecules. Compared to dielectric barrier discharges, only a small amount of ozone is generated, thereby reducing ozone pollution. In contrast, a high-frequency arc-like discharge produces increased amounts of nitrogen oxides, particularly when air is used as the working gas. By using such a reactive gas stream to produce the plasma-activated liquid, the formation of nitrous acid or nitric acid in the liquid and thus a low pH value of the plasma-activated liquid can be achieved, thereby achieving a good cleaning and disinfection effect.

Furthermore, a reactive gas flow generated in this way has been shown to be gentler on certain membranes, such as those used in dialysis machines. Such membranes are advantageous for the device, but are prone to premature wear when a reactive gas flow generated by dielectric barrier discharge is used.

To generate the arc-like electrical discharge, at least two electrodes are provided, as well as a voltage source for applying a high-frequency high voltage to the electrodes. The high-frequency high voltage for generating a high-frequency arc-like discharge has, in particular, a voltage in the range of 1-100 kV, preferably 1-50 kV, more preferably 10-50 kV, and a frequency of 1-300 kHz, in particular 1-100 kHz, preferably 10-100 kHz, more preferably 10-50 kHz.

In one embodiment, particularly according to the second aspect, the reactive gas stream, in particular a plasma jet, is generated by means of dielectric barrier discharges between electrodes in a working gas stream. In a corresponding embodiment, the plasma source is configured to generate the reactive gas stream by means of dielectric barrier discharges in a working gas. Dielectric barrier discharges can generate very high concentrations of certain reactive species, in particular ozone, in the gas stream. Using such a reactive gas stream to produce the plasma-activated liquid can induce the formation of hydroxyl radicals in the liquid, which produce a good disinfection effect.

To generate dielectric barrier discharges, at least two electrodes and a dielectric arranged therebetween can be provided, which prevents direct electrical discharges between the two electrodes. Preferably, one of the electrodes is grounded. Furthermore, a voltage source is provided, in particular, to apply a high-frequency high voltage to the electrodes, for example, with a voltage intensity in the range of 5 to 15 kV and a voltage frequency in the range of 7.5 to 25 kHz, in particular 13 to 14 kHz.

In one embodiment, particularly according to the second aspect, the reactive gas stream, in particular a plasma jet, is generated both by means of an arc-like electrical discharge, in particular a high-frequency arc-like discharge, between electrodes in a working gas stream and by means of dielectric barrier discharges between electrodes in a working gas stream. The generation by means of an arc-like electrical discharge and the generation by means of dielectric barrier discharges can occur simultaneously and/or alternately. In a corresponding embodiment, the device comprises, in addition to the plasma source, a further plasma source which is configured to generate a reactive gas stream during operation, wherein the plasma source is configured to generate the reactive gas stream by means of an arc-like discharge in a working gas, and the further plasma source is configured to generate the reactive gas stream by means of dielectric barrier discharges in a gas stream. The gas streams generated by the plasma source and the further plasma source can then be directed into the first spatial region.

In this way, various reactive species, in particular hydroxyl radicals in the first operating mode and nitric acid or nitrous acid in the second operating mode, can be present in the liquid enriched, thereby further improving the disinfection effect of the plasma-activated water. In this embodiment, the plasma source is preferably designed like the plasma source described below.

In a further embodiment, in particular according to the second aspect, the plasma source has a working gas supply that is configured to supply the plasma source with ambient air as the working gas. The use of ambient air as the working gas eliminates the need for a separate working gas supply, thereby enabling more flexible use of the device. The working gas supply can, in particular, comprise a fan or compressor to supply the working gas to the plasma source at a predetermined pressure and/or volume flow. To prevent contamination or microbial contamination of the device, the working gas supply preferably comprises a filter, for example a fine dust filter and/or a bacteria and/or virus filter.

In one embodiment, particularly according to the second aspect, the device comprises a pump configured to pump liquid through the second spatial region. In this way, the production rate can be controlled. Furthermore, the necessary pressure can be generated to pump the liquid through the second spatial region.

Further features and advantages of the method and device for cleaning laundry as well as the method and device for producing plasma-activated liquid will become apparent from the following description of exemplary embodiments, with reference to the attached drawing.

• 1 eine Plasmaquelle in Form einer Plasmadüse zur Erzeugung eines atmosphärischen Plasmastrahls mittels einer bogenartigen Entladung,
• 2 eine Plasmaquelle in Form einer Düse zur Erzeugung eines reaktiven Gasstroms mittels dielektrischer Barriereentladungen,
• 3 eine Vorrichtung zur Herstellung von plasmaaktiviertem Wasser,
• 4 ein erstes Ausführungsbeispiel der Vorrichtung und des Verfahrens zur Reinigung von Wäsche,
• 5 ein zweites Ausführungsbeispiel der Vorrichtung und des Verfahrens zur Reinigung von Wäsche,
• 6 ein Ausführungsbeispiel der Vorrichtung und des Verfahrens zur Herstellung von plasmaaktivierter Flüssigkeit,
• 7 ein Diagramm mit Ergebnissen einer ersten Versuchsreihe und
• 8 ein Diagramm mit Ergebnissen einer zweiten Versuchsreihe.

In the drawing show

• 1 a plasma source in the form of a plasma nozzle for generating an atmospheric plasma jet by means of an arc-like discharge,
• 2 a plasma source in the form of a nozzle for generating a reactive gas flow by means of dielectric barrier discharges,
• 3 a device for producing plasma-activated water,
• 4 a first embodiment of the device and method for cleaning laundry,
• 5 a second embodiment of the device and method for cleaning laundry,
• 6 an embodiment of the device and method for producing plasma-activated liquid,
• 7 a diagram with results of a first series of tests and
• 8 a diagram showing the results of a second series of experiments.

1 shows a schematic sectional view of a plasma source 2 in the form of a plasma nozzle for generating a reactive gas stream 26 in the form of an atmospheric plasma jet by means of an arc-like discharge,

The plasma nozzle 2 has a metal nozzle tube 4 that tapers conically to a nozzle opening 6. At the end opposite the nozzle opening 6, the nozzle tube 4 has a swirl device 8 with an inlet 10 for a gas stream 23, in particular a working gas, for example, air or nitrogen.

An intermediate wall 12 of the swirl device 8 has a ring of circumferentially inclined bores 14 through which the gas flow is swirled. The downstream, conically tapered part of the nozzle tube is therefore flowed through by the gas flow in the form of a vortex 16, the core of which runs along the longitudinal axis of the nozzle tube. An internal electrode 18 is arranged centrally on the underside of the intermediate wall 12 and projects coaxially into the nozzle tube in the direction of the tapered section. The electrode 18 is electrically connected to the intermediate wall 12 and the remaining parts of the swirl device 8. The swirl device 8 is electrically insulated from the nozzle tube 4 by a ceramic or quartz glass tube 20. A high-frequency high voltage, generated by a transformer 22, is applied to the electrode 18 via the swirl device 8. The inlet 10 is supplied with a gas stream 23 via a line (not shown). The nozzle tube 4 is grounded. The applied voltage generates a high-frequency discharge in the form of an arc 24 between the electrode 18 and the nozzle tube 4.

The terms "arc,""arcdischarge," and "arc-like discharge" are used here as a phenomenological description of the discharge, since the discharge occurs in the form of an arc. The term "arc" is also used elsewhere to describe the discharge type 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.

However, due to the swirling flow of the working gas, this arc is channeled in the vortex core on the axis of the nozzle tube 4, so that it only branches out to the wall of the nozzle tube 4 in the area of the nozzle opening 6. The working gas, which rotates at high flow velocity in the area of the vortex core and thus in the immediate vicinity of the arc 24, comes into intimate contact with the arc and is thereby partially converted into the plasma state, so that an atmospheric plasma jet 26 exits the plasma nozzle 2 through the nozzle opening 6.

2 shows in perspective schematic sectional view a further plasma source 32 in the form of a nozzle for generating a reactive gas flow by means of dielectrically impeded discharge.

The nozzle 32 comprises a metal nozzle tube 34, at the upstream end 35 of which a distributor head 36 is arranged with an inlet 37 for a gas stream 38, for example, air, and with an annular distribution channel 40. At the opposite downstream end 42 of the nozzle tube 34, an outlet nozzle 44 is arranged with a nozzle opening 46, from which the reactive gas stream 38 enriched with reactive species emerges during operation.

A ceramic tube 48 extends from the distributor head 36 through the nozzle tube 34 into the outlet nozzle 44 such that an annular discharge channel 50 extends from the distributor channel 40 between the nozzle tube 34 and the ceramic tube 48 to the outlet nozzle 44. Instead of a ceramic tube, a tube made of quartz glass, for example, can also be used.

On the inside of the ceramic tube 48, a tubular high-voltage electrode 52 made of metal is arranged. This electrode is connected via a high-voltage cable 54 to a transformer 56, which can be used to apply a high-frequency high voltage between the high-voltage electrode 52 and the grounded nozzle tube 34, which acts as a counter electrode. Instead of a tubular high-voltage electrode 52, a differently shaped high-voltage electrode, for example, in the form of a rounded sheet, is also possible.

Insulating plugs 58 are arranged in the ceramic tube 48, which enclose the high-voltage electrode 52 and further prevent working gas from flowing into the area of the high-voltage electrode 52 or out of the nozzle 32 through the ceramic tube 48. Furthermore, a sealing ring 60 is inserted into an annular groove 62 on the distributor head 36, which seals the distributor head 36 to the ceramic tube 48.

A coolant line 64 may be provided around the nozzle tube 34, through which a coolant can be conducted during operation to cool the nozzle tube 34. The coolant line 64 may, for example, extend spirally around the nozzle tube 34, as shown.

In operation, a gas stream 38 is introduced through the inlet 37 into the distributor head 36 so that the gas stream 38 flows through the annular discharge channel 50.

With the transformer 56, a high-frequency high voltage is applied between the high-voltage electrode 52 and the nozzle tube 34, so that dielectrically impeded discharges occur in the discharge channel 50 in the region of the high-voltage electrode 52, by means of which reactive species, in particular ozone, are generated in the gas stream 38 flowing there.

The reactive gas stream 38 enriched with the reactive species exits the nozzle opening 46.

3 shows a device 70 for producing plasma-activated water in a schematic sectional view.

The device 70 comprises a container 72, for example made of glass, which surrounds an activation chamber 74 for holding a quantity of water 76. Instead of a glass cylinder, containers of other shapes can also be used. Furthermore, the container can also be made of plastic, for example, preferably PVC, or metal. A disc aerator 78 is provided at the bottom of the container, which has a supply line 80 for a working gas and a membrane 82.

A plasma source 84 for generating a reactive gas stream is connected to the supply line 80 in such a way that the reactive gas stream 86 emerging from the plasma source 84 during operation is introduced into the disc aerator 78 via the supply line 80. The gas-permeable membrane 82 has a plurality, in particular thousands, of small openings (in the schematic representation in 3 the openings are exaggeratedly large.) through which the reactive gas stream 86 enters the water 76 in the form of small bubbles. In this way, the water 76 located in the activation chamber 74 comes into intimate contact with the reactive gas stream 86 from the plasma source 84, so that the active species in the reactive gas stream 86, in particular ozone and/or nitrogen oxides, form long-lived reactive species, in particular hydroxyl radicals, hydrogen peroxide, nitrous acid or nitric acid, in the water 76. In this way, plasma-activated water can be produced.

The container 72 with the disc aerator 78 accordingly represents a reaction device of the device 70.

Instead of the disc aerator 78, an aeration element made of porous material, for example, porous ceramic, can be arranged in the container 72, into which the reactive gas stream 86 is introduced via the supply line 80. Due to the large inner surface of such aeration element, an intensive interaction occurs between the reactive gas stream 86 and the water 76, which also allows the production of plasma-activated water.

The plasma source 84 can in particular, like the plasma source 2, be made of 1 Such a plasma source generates a reactive gas stream in the form of a plasma jet 26, which has a relatively high content of nitrogen oxides as well as partially ionized atoms and molecules. The interaction of such a gas stream with the water 76 results in plasma-activated water containing nitrous acid and/or nitric acid and thus with a low pH value. It has been found that plasma-activated water produced in this way has good cleaning, deodorizing, and disinfecting properties. Comparative tests have also shown that the disinfecting effect of this plasma-activated water is better than an aqueous solution with a comparable content of nitrous acid and/or nitric acid, which was produced without plasma activation.

Alternatively, the plasma source 84 can also be made like the plasma source 32 from 2 Such a plasma source generates a reactive gas stream 38 that has a relatively high ozone content and, if appropriate, partially ionized atoms and molecules. The interaction of such a gas stream with the water 76 results in plasma-activated water containing hydroxyl radicals and, if appropriate, hydrogen peroxide. It has been found that plasma-activated water generated in this way also has a good disinfection effect.

It is also conceivable to use multiple plasma sources. For example, in addition to the plasma source 84, a further plasma source 85 can be provided, which feeds a further reactive gas stream 87 via the supply line 80, which in this case has a T-piece, for example, to the disc aerator 78. In particular, different types of plasma sources can be used to adjust the quality of the plasma-treated water as required. If, for example, a plasma source such as the plasma source 2 from 1 and as plasma source 85 a plasma source such as the plasma source 32 from 2 used, plasma-activated water can be produced which has a low pH value due to the nitrogen oxides from plasma source 84 and a content of hydroxyl radicals due to the ozone from plasma source 85. The plasma-activated water produced in this way has proven to be a particularly effective disinfectant in tests. In addition to the disinfection effect, the combination of reactive gas streams from a plasma source as in 1 and a plasma source as in 2 has also proven advantageous because the plasma jet 26, particularly when using air as the working gas, converts part of the ozone contained in the reactive gas stream 38, whereby the ozone load can be reduced while at the same time the plasma-activated water has a good disinfection effect.

In order to be able to remove, in particular to suck off, the portion of the reactive gas stream 86 which is not dissolved in the water 76 in a controlled manner, the container 72 has a lid 88 with a suction nozzle 90, to which a 3 The suction nozzle 90 and the suction device (not shown) thus represent a gas discharge device 92 for extracting a gas stream from the activation chamber 74.

Furthermore, the device 70 has a 3 inlet 94 connected to a water supply (not shown) in order to fill the activation chamber 74 with water 76. The inlet 94 and the water supply (not shown) thus represent a water supply device 96 for introducing water into the activation chamber 74.

The device 70 further comprises an outlet 98 for discharging the plasma-activated water 99 from the activation chamber 74. For example, a valve or a pump (not shown) may be connected to the outlet 98.

4 shows a schematic representation of a first embodiment of the device and method for cleaning laundry.

The device 100 for cleaning laundry comprises a transport device 102 for transporting laundry items 104 along a predetermined route 106 through the device 100.

In the case of the device 100, the transport device 102 comprises a plurality of conveyor belts 105a-d. The laundry items 104, which may be flat laundry, for example, bed linen, table linen, terry cloth, and the like, can be placed on the first conveyor belt 105a in the transport direction and transported by the transport device 102 along the path 106 defined by the conveyor belts 105a-d.

The device 100 comprises a washing device 108 in the form of one or more washing machines in which the laundry items 104 can be washed before the laundry items 104 are placed - manually or automatically - onto the conveyor belt 105a.

The device 100 further comprises an intermediate drying area 110, a loading area 120, a further intermediate drying area 130, a rinsing area 140, a final drying area 150 and a folding device 160, wherein the transport device 102 is configured to transport the laundry items 104 successively through the intermediate drying area 110, the loading area 120, the further intermediate drying area 130, the rinsing area 140 and the final drying area 150 to the folding device 160.

The device 100 further comprises a first moisture removal device 112 and a second moisture removal device 132, each of which is configured to remove moisture from the laundry items 104 transported through the intermediate drying area 110 and the further intermediate drying area 130, respectively.

For this purpose, the first and second moisture removal devices 112, 132 each comprise two oppositely arranged, driven rollers 114, 134 through which the laundry items 104 are guided and rolled, so that part of the moisture contained in the laundry items 104 is pressed out of them.

The device 100 further comprises a spray device 122 configured to spray items of laundry 104 transported by the transport device 102 through the application area 120 with plasma-activated water 124. For this purpose, the spray device 122 has one or more spray nozzles 126 connected to a source 128 for plasma-activated water.

The source 128 for plasma-activated water may comprise a reservoir containing plasma-activated water. Alternatively or additionally, the source 128 may also comprise a device for producing plasma-activated water, for example, such as the device 70 of 3 or as described below in connection with 6 described device 500 can be designed.

The device 100 further comprises a rinsing device 142, which is configured to rinse laundry items 104 transported through the rinsing area 140 with preferably clear water 144. For this purpose, the rinsing device 142 has one or more spray nozzles 146, to which a source 148 for preferably clear water is connected, for example, a container with water or a water supply line.

The device 100 further comprises a third moisture removal device 152, which is configured to remove moisture from the laundry items 104 transported through the final drying area 150.

For this purpose, the third moisture removal device 152 comprises two oppositely arranged, driven rollers 154 through which the laundry items 104 are guided and rolled, so that a portion of the moisture contained in the laundry items 104 is pressed out of them. Furthermore, the third moisture removal device 152 comprises a tunnel dryer 156 in which the laundry items 104 transported through the tunnel dryer 156 are dried, for example, with hot air. The laundry items 104 can also be smoothed in the tunnel dryer 156, for example, by applying hot steam to the laundry items 104.

During operation, the laundry items 104 are first washed in the washing device 108 and then, either wet or after spinning in the washing device 108, are placed one after the other onto the conveyor belt 105a. The residual moisture content of the laundry items 104 can, in particular, be significantly above 80% at this time. The individual laundry items 104 are transported along the path 106 by the conveyor belts 105a-d. As they are rolled by the rollers 114, moisture is pressed out of the laundry items 104, so that upon reaching the loading area 120, the laundry items preferably have a residual moisture content in the range of 10-80%, preferably 15-70%, more preferably 30-70%, and particularly preferably 30-50%. The residual moisture content can, in particular, also be less than 50%. In the application area 120, the laundry items 104 are subjected to plasma-activated water 124 until thoroughly wet, whereby the laundry items 104 are further cleaned, optionally disinfected, and/or deodorized. Subsequently, the moisture introduced into the laundry items 104 by the plasma-activated water 124 is at least partially pressed out of the laundry items 104 by the rollers 134. Any residues of the plasma-activated water 124 remaining in the laundry items 104 are then rinsed out of the laundry items 104, preferably completely, by spraying them with clean water 144. The rinsed laundry items 104 are then smoothed, if necessary, and finally dried using the rollers 154 and the tunnel dryer 156 before being folded using the folding device 160.

In a further embodiment, the laundry items 104 are placed on the conveyor belt 105a in a cupboard-dry state (residual moisture content up to 5%). Washing in the washing device 108 can be omitted. Instead of the intermediate drying area 110 with the moisture removal device 112, this further embodiment preferably provides a humidification area with a humidification device configured to humidify the laundry items transported through the humidification area, preferably to a residual moisture content in the range of 10-80%, in particular 15-70%.

5 shows a schematic representation of another embodiment of the device and method for cleaning laundry. The device 200 has a similar structure to the device 100. In its function, the components of 4 corresponding components are in 5 with reference numbers increased by 100 and in this respect, reference is made to the above description 4 referred to.

The device 200 differs from the device 100 in that the transport device 202 comprises transport carriers 205 in the form of coat hangers, instead of conveyor belts, that are conveyed along a guide profile 203. A conveyor 207, for example, a driven train running in the guide profile 203, can be provided to convey the transport carriers 205, which carries the transport carriers 205 along the guide profile 203.

The laundry items 204, which may be, for example, shaped garments, for example clothing such as shirts, trousers, jackets and the like, can be hung one after the other on the clothes hangers 205 after washing in the washing device 208 - manually or automatically - and are transported with the clothes hangers 205 by the transport device 202 along the path 206 predetermined by the guide profile 203.

The device 200 further differs from the device 100 in that the first, second and third moisture removal devices 212, 232 and 252 each comprise a tunnel dryer 214, 234 and 254.

Furthermore, the device 200 lacks a folding device.

During operation, the laundry items 204 are first washed in the washing device 208 and then hung individually, one after the other, on the clothes hangers 205, either wet or after spinning in the washing device 208. The residual moisture content of the laundry items 204 can be significantly above 80% at this time. The individual laundry items 204 are transported along the path 206 with the clothes hangers 205 conveyed via the guide profile. Drying in the tunnel dryer 214 removes moisture from the laundry items 204, so that upon reaching the loading area 220, the laundry items preferably have a residual moisture content in the range of 10-80%, preferably 15-70%, more preferably 30-70%, and particularly preferably 30-50%. The residual moisture content can, in particular, also be less than 50%. In the application area 220, the laundry items 204 are subjected to plasma-activated water 224 until they are thoroughly wet, whereby the laundry items 204 are further cleaned, optionally disinfected, and/or deodorized. Subsequently, the moisture introduced into the laundry items 204 by the plasma-activated water 224 is at least partially removed from the laundry items 204 as they pass through the tunnel dryer 234. Any residues of the plasma-activated water 224 remaining in the laundry items 204 are then rinsed out of the laundry items 204, preferably without leaving any residue, by spraying them with clean water 244. The rinsed laundry items 204 are then finally dried in the tunnel dryer 254 and can then be removed from the hangers 205 after being cleaned. Alternatively, the laundry items 204 can be removed from the transport device 202 together with the hangers 205.

In a further embodiment, the laundry items 204 are hung in a cupboard-dry state on the clothes hangers 205. Washing in the washing device 208 can be omitted. Instead of the intermediate drying area 210 with the moisture removal device 212, this further embodiment preferably provides a humidification area with a humidification device configured to humidify the laundry items 204 transported through the humidification area, preferably to a residual moisture content in the range of 10-80%, in particular 15-70%.

6 shows a schematic representation of an embodiment of the device and the method for producing plasma-activated liquid.

The device 500 comprises a plasma source 502, which is configured to generate a reactive gas stream 504, in particular an atmospheric plasma jet, during operation. The plasma source 502 can, for example, be configured like the plasma nozzle 2 of 1 or the plasma source 32 from 2 be trained.

It is also conceivable that the device 500 comprises a further plasma source in addition to the plasma source 502, wherein the plasma source 502, like the plasma nozzle 2, consists of 1 and the further plasma source like the plasma source 32 from 2 and the reactive gas streams emerging from the plasma source and the further plasma source together form the reactive gas stream 504.

The device 500 further comprises a reactor 510, whose housing or walls 512 form a first tube-like space region 514 and a second tube-like space region 516, which run alongside one another and are separated from one another by a membrane 518. In 6 The two ends and a central section of the reactor 510 are enlarged and shown in a schematic sectional view. The connections to the first and second space areas 514, 516 at the ends of the reactor 510, described below, are shown in 6 only represented highly schematically by simple lines.

The plasma source 502 is connected to the first hose-like space region 514 in such a way that the reactive gas stream 504 emerging from the plasma source 502 during operation is passed through the first hose-like space region 514.

Furthermore, a liquid source 530, in particular a water source, for example, a water reservoir or a water supply line, is connected to the second hose-like spatial region 516 in such a way that, during operation, a liquid 531 is passed through the second hose-like spatial region 516 as a liquid flow 532. A pump 534 can be provided to maintain the liquid flow 532. In this case, the liquid 531 is, for example, water.

The membrane 518 is designed in such a way that the water 531 of the water stream 532 flowing through the second space area 516 cannot reach the first space area 516. Furthermore, the Membrane 518 is configured such that reactive species 520 of the reactive gas stream 504 from the first spatial region 514 enter the water 531 of the water stream 532 flowing through the second spatial region 516, so that the species 520 accumulate in the water 531 and the water 531 of the water stream 532 is thus plasma-activated, so that plasma-activated water 536 exits the reactor 510 and is available for intermediate storage or immediate use. The reactor 510 accordingly represents a reaction device of the device 500.

For example, a conventional dialysis membrane can be used as membrane 518.

With the device 500, plasma-activated liquid 536, in this case for example plasma-activated water, can be produced in a continuous process.

Experiments were conducted to investigate the effectiveness of the previously described procedure.

For the tests, identical cotton textile samples were first provided and treated with a solution containing the bacterium Staphylococcus arlettae. The textiles were then dried to an initial moisture content of less than 5% ("cupboard dry"), specifically 3-5%.

Furthermore, with a device which, like the device 70 in 3 was designed and a plasma source 84 as in 1 Two liquid quantities A and B of plasma-activated water were prepared. For this purpose, a quantity of demineralized water (DE water) was added to the activation chamber 74 and then plasma-activated by introducing the gas stream emerging from the plasma source 84. Liquid quantity B was plasma-activated for a longer time than liquid quantity A. After completion, the pH and electrical conductivity of liquid quantities A and B were determined, resulting in the values shown in Table 1: Table 1 PH value Electrical conductivity Amount of liquid A (PAW A) 2.06 9.41 mS Fluid volume B (PAW B) 1.55 19.70 mS

Liquid B shows a lower pH and a higher electrical conductivity than liquid A, which indicates a higher concentration of reactive species due to the longer treatment time in the activation chamber.

Test series 1:

For test series 1, some of the textile samples, pre-dried and treated with bacteria as described above, were prepared. Some of the textile samples were also pre-moistened with demineralized water. The textile samples were then sprayed with plasma-activated water (PAW), some with plasma-activated water of liquid batch A (PAW A) and others with plasma-activated water of liquid batch B (PAW B), after each of the liquid batches had been allowed to stand for less than 2 hours.

The number of colony-forming units (CFU) per ml was then determined for each textile sample. For this purpose, a bacterial recovery solution was added to each textile sample after a contact time of 30 seconds with the plasma-activated water, which was then used to determine the bacterial count. Furthermore, the initial bacterial count (CFU ₀₎ (also CFU per ml) was determined for one of the pre-dried textile samples, also by adding a bacterial recovery solution.

7 shows the results of these tests. The parameters of the individual tests are listed in Table 2 below. The (residual) moisture content in % refers to the weight of water in the laundry item relative to the (dry) weight of the laundry item. Table 2 sample PAW used Moisture before spraying Humidity after spraying A1 PAW A cupboard dry 100% A2 cupboard dry 200% A3 50% 200% B1 PAW B cupboard dry 100% B2 cupboard dry 200% B3 50% 200%

As the test results from Test Series 1 show, effective disinfection of laundry items requires a sufficient amount of reactive species in the plasma-activated water. Therefore, plasma-activated water with a pH of 1.8 or less and/or an electrical conductivity of 15 mS or more is preferably used.

Furthermore, the test results show that effective disinfection requires a certain pre-moisture level of the laundry items. Therefore, the laundry items preferably have a residual moisture content in the range of 15% - 80% at the beginning of the spraying process.

Test series 2:

For test series 2, additional textile samples, pre-dried and treated with bacteria as described above, were prepared. Some of the textile samples were pre-moistened with deionized water. Some of the textile samples were pre-moistened with a cleaning fluid in the form of an aqueous washing solution consisting of deionized water and a 4 ml/l portion of an alkaline, phosphate-free detergent (Olisso, available from Burnus Professional GmbH & Co. KG, Steinau a.d. Straße, Germany).

The textile samples were then sprayed with plasma-activated water (PAW), specifically with plasma-activated water from liquid batch B (PAW B) after a standing time of 24 hours. The pH and electrical conductivity of liquid batch B were re-determined after the standing time of 24 hours. The results are shown in Table 3. Table 3 PH value Electrical conductivity Liquid volume B (after 24 hours) 1.5 19.7 mS

The number of colony-forming units per ml was then determined on the individual textile samples, analogous to test series 1. The initial bacterial count (CFU ₀₎ was determined in test series 2 on textile samples pre-moistened with deionized water or washing solution.

8 shows the results of these tests. The parameters of the individual tests are listed in Table 4 below. The (residual) moisture content in % refers to the weight of water in the laundry item relative to the (dry) weight of the laundry item. Table 4 sample PAW used Pre-humidification with Moisture before spraying Humidity after spraying C PAW B demineralized water 50% 200% D VE/Olisso solution 50% 200% E demineralized water 15% 200%

As the test results from test series 2 show, a passable disinfection effect can be achieved by spraying with plasma-activated water even after a standing time of 24 hours. However, compared to test series 1, the disinfection effect is reduced because plasma-activated water contains, among other things, short-lived reactive species with disinfectant effects after production, which have already partially or completely degraded after 24 hours, so that in test series 2, primarily only the longer-lived species are effective. Therefore, it is preferable to generate the plasma-activated water not too long before spraying the laundry items, preferably no more than 6 hours before spraying, and particularly preferably in-line during the laundry cleaning process.

As the test results from Test Series 2 further demonstrate, a good disinfection effect also occurs when using the alkaline wash solution, i.e., when the low pH of the plasma-activated water is neutralized when mixed with the alkaline wash solution (pH approximately 12). The preferred pH of the plasma-activated water of 1.8 or less refers accordingly to the pH before spraying the laundry items.

List of reference symbols:

2, 32, 84, 85

Plasma source

4, 34

nozzle tube

6, 46

Nozzle opening

8

Swirl device

10

inlet

12

partition wall

14

Drilling

16

vortex

18

inner electrode

20

Quartz glass tube

22, 56

transformer

23

Gas flow

24

arc

35

upstream end

36

distributor head

37

inlet

26, 38, 86, 87

reactive gas stream

40

distribution channel

42

downstream end

44

Outlet nozzle

48

ceramic tube

50

discharge channel

52

High-voltage electrode

54

High-voltage cables

58

Plug

60

Sealing ring

62

Groove

64

coolant line

70

Device for producing plasma-activated water

72

container

74

Activation room

76, 531

Water

78

Disc aerator

80

supply line

82

membrane

86, 87

reactive gas stream

88

Lid

90

Suction nozzle

92

Gas discharge device

94

inlet

96

Water supply device

98

Outlet

99, 124, 224

plasma-activated water

100, 200

device

102, 202

Transport device

105a-d

Conveyor belts

104, 204

item of laundry

106, 206

Route

108, 208

Washing facility

110, 130, 210, 230

Intermediate drying area

112, 132, 152, 212, 232, 252

Moisture removal device

114, 134, 154

rollers

120, 220

Exposure area

122, 222

Spray device

126, 146, 226, 246

spray nozzle

128, 228

Source of plasma-activated water

140, 240

Sink area

142, 242

Flushing device

144, 244

Water

148, 248

Source of clear water

150, 250

Final drying area

156, 214, 234, 254

Tunnel dryer

160

Folding device

203

Leadership profile

205

Transport carrier

207

Sponsors

500

device

502

Plasma source

504

reactive gas stream

510

reactor

512

Walls of the reactor

514

first room area

516

second room area

518

membrane

520

reactive species

530

Fluid source

532

Liquid flow

534

pump

536

plasma-activated liquid

QUOTES CONTAINED IN THE DESCRIPTION

This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2014/090755 A1 [0002, 0004]
• WO 2021/223986 A1 [0006]
• DE 10 2020 104 261 A1 [0026]

Claims (25)

A method for cleaning laundry, in particular flat laundry, - in which one or more items of laundry (104, 204) are exposed to plasma-activated water (124, 224, 536) by spraying the plasma-activated water (124, 224, 536) onto the one or more items of laundry (124, 224, 536) by means of at least one spraying device (122, 222). Procedure according to Claim 1 , characterized in that the plasma-activated water (124, 224, 536) is produced by bringing a reactive gas stream (26, 38, 504), in particular a plasma jet, into contact with liquid water (76, 531). Procedure according to Claim 2 , characterized in that the reactive gas stream (26, 38, 504), in particular plasma jet, is generated by means of an arc-like electrical discharge and/or dielectric barrier discharges between electrodes (4, 18; 34, 52) in a working gas stream (23, 38). Procedure according to Claim 2 or 3 , characterized in that the plasma-activated water (124, 224, 536) is produced by a method according to one of the Claims 18 until 21 and/or with a device according to one of the Claims 22 until 25 . Method according to one of the Claims 1 until 4 , characterized in that - the one or more items of laundry (104, 204) are placed and transported on a transport carrier (105a-d), in particular a conveyor belt, and are sprayed with the plasma-activated water (124, 224, 536) on the transport carrier (105a-d) or - that the one or more items of laundry (104, 204) are suspended and transported on transport carriers (205) arranged one behind the other, in particular clothes hangers, and are sprayed with the plasma-activated water (124, 224, 536) while hanging on the transport carriers (205). Method according to one of the Claims 1 until 5 , characterized in that the one or more items of laundry (104, 204) are washed before spraying with the plasma-activated water (124, 224, 536), in particular by spraying with a cleaning liquid or immersing in a cleaning liquid. Method according to one of the Claims 1 until 6 , characterized in that the one or more laundry items (104, 204) have a residual moisture in the range 10 - 80% at the start of spraying with the plasma-activated water (124, 224, 536). Method according to one of the Claims 1 until 7 , characterized in that the one or more items of laundry (104, 204) are moistened, in particular with water or a cleaning liquid, before being sprayed with the plasma-activated water (124, 224, 536). Method according to one of the Claims 1 until 8 , characterized in that moisture is removed from the one or more items of laundry (104, 204) before spraying with the plasma-activated water (124, 224, 536), in particular by drying, spinning, rolling and/or wringing. Method according to one of the Claims 1 until 9 , characterized in that - the one or more items of laundry (104, 204) are rinsed after being sprayed with the plasma-activated water (124, 224, 536), in particular with water (144, 244), and/or - that moisture is removed from the one or more items of laundry (104, 204) after being sprayed with the plasma-activated water (124, 224, 536), in particular by rolling and/or drying. Device (100, 200) for cleaning laundry, in particular flat laundry, in particular for carrying out a method according to one of the Claims 1 until 10 , - with a transport device (102, 202) for transporting a plurality of laundry items (104, 204) along a predetermined route (106, 206) through the device (100, 200), wherein the transport device (102, 202) is designed to transport the laundry items (104, 204) through an application area (120, 220) of the device (100, 200), - with a spray device (122, 222) which is designed to spray laundry items (104, 204) transported by the transport device (102, 202) through the application area (120, 220) with plasma-activated water (124, 224, 536), - with a source (128, 228) of plasma-activated water (124, 224, 536) connected to the spray device (122, 222) for supplying it with plasma-activated water (124, 224, 536). Device according to Claim 11 , characterized in that the source (124, 224, 536) for plasma-activated water (124, 224, 536) comprises a device (70, 500) for producing plasma-activated water (124, 224, 536), in particular according to one of the Claims 22 until 25 . Device according to Claim 11 or 12 , characterized in that - the transport device (102, 202) comprises one or more conveyor belts (105a-d) and/or - that the transport device (102, 202) has one or more conveyors (207) for conveying transport carriers (205) for laundry items (204), in particular clothes hangers, along a guide profile (203). Device according to one of the Claims 11 until 13 , characterized in that the device (100, 200) comprises a washing device (108, 208) for washing laundry items (104, 204). Device according to one of the Claims 11 until 14 , characterized in that the device (100, 200) comprises a moistening device for moistening the laundry items (104, 204), in particular with water or a cleaning liquid. Device according to one of the Claims 11 until 15 , characterized in that the transport device (102, 202) is designed to transport the laundry items (104, 204) through an intermediate drying area (110, 210) of the device (100, 200) before the laundry items (104, 204) are transported through the application area (120, 220), wherein the device (100, 200) has a moisture removal device (112, 212) which is designed to remove moisture from the laundry items (104, 204) transported by the transport device (102, 202) through the intermediate drying area (110, 210), in particular by drying, spinning, rolling and/or wringing. Device according to one of the Claims 11 until 16 , characterized in that - the transport device (102, 202) is designed to transport the laundry items (104, 204) through a rinsing area (140, 240) after the laundry items (104, 204) have been transported through the loading area (120, 220), wherein the device (100, 200) has a rinsing device (142, 242) which is designed to rinse the laundry items (104, 204) transported through the rinsing area (140, 240) by the transport device (102, 202), in particular with water (144, 244), and/or - that the transport device (102, 202) is designed to transport the laundry items (104, 204) through a final drying area (150, 250) of the device (100, 200) after the laundry items (104, 204) have been transported through the loading area (120, 220) and/or the optional rinsing area (140, 240), wherein the device (100, 200) has a moisture removal device (152, 252) which is designed to remove moisture from the laundry items (104, 204) transported by the transport device (102, 202) through the final drying area (150, 250), in particular by drying, spinning, rolling and/or wringing. A method for producing plasma-activated liquid (124, 224, 536), in particular plasma-activated water, - in which a reactive gas stream (504) is generated, in particular an atmospheric plasma jet, - in which a first spatial region (514) is flowed through by the reactive gas stream (504), - in which a liquid (531), in particular water, is flowed through by a second spatial region (516), - wherein the first spatial region (514) and the second spatial region (516) are arranged adjacent to one another and separated from one another by a membrane (518) which is permeable to reactive species (520) from the first spatial region (514) and impermeable to liquid (531) from the second spatial region (516). Procedure according to Claim 18 , characterized in that the first spatial region (514) and/or the second spatial region (516) are tubular or hose-shaped. Procedure according to Claim 18 or 19 , characterized in that the plasma-activated liquid (536) after flowing through the second spatial region (516) is temporarily stored or used to act on an object. Method according to one of the Claims 18 until 20 , characterized in that the reactive gas stream (504), in particular plasma jet, is generated by means of an arc-like electrical discharge and/or dielectric barrier discharges between electrodes (4, 18; 34, 52) in a working gas stream (23, 38). Device (500) for producing plasma-activated liquid (124, 224, 536), in particular plasma-activated water, in particular for carrying out a method according to one of the Claims 18 until 21 , - with a plasma source (2, 32, 502) which is designed to generate a reactive gas stream (26, 38), in particular an atmospheric plasma jet, during operation, - with a first spatial region (514) through which the reactive gas stream (26, 38) generated by the plasma source (2, 32, 502) during operation can flow, and with a second spatial region (516) through which a liquid (531), in particular water, can flow during operation, - wherein the first spatial region (514) and the second spatial region (516) are arranged adjacent to one another and separated from one another by a membrane (518) which is permeable to reactive species (520) from the first spatial region (514) and impermeable to liquid (531) from the second spatial region (516). Device according to Claim 22 , characterized in that the first spatial region (514) and/or the second spatial region (516) are tubular or hose-shaped. Device according to Claim 22 or 23 , characterized in that the plasma source (2, 32, 502) is designed to generate the reactive gas stream (26, 38), in particular a plasma jet, by means of an arc-like electrical discharge and/or dielectric barrier discharges between electrodes (4, 18; 34, 52) in a working gas stream (23, 38). Device according to one of the Claims 12 until 24 , characterized in that the device (500) has a pump (534) which is designed to pump liquid (531) through the second spatial region (516).

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