Water softening device for a water-bearing household appliance, water-bearing household appliance and method for operating a water-bearing household appliance

Abstract

Water softening device (100) for a water-bearing household appliance (1), in particular a dishwasher, for softening water (110) supplied to the household appliance (1), comprising an agent (120) for fixing activatable molecules (130), wherein the activatable molecules (130) have an activated state (131), a deactivated state (132) and a complexed state (133), wherein the molecules (130) in the activated state (131) are configured to transition from the activated state (131) to the complexed state (133) by forming complexes with ions (140) dissolved in water (110), and an activation device (150) configured to bring the activatable molecules (130) into the activated state (131), and a treatment chamber (160) in which the agent (120) for fixing the activatable molecules (130) can be brought into contact with the water (110).

Description

[0001] The present invention relates to a water softening device for a water-bearing household appliance, a water-bearing household appliance with such a water softening device and a method for operating a water-bearing household appliance with such a water softening device.

[0002] Conventional household appliances, such as dishwashers and washing machines, use tap water supplied via the main water line. This tap water contains various dissolved molecules and / or ions, such as calcium and / or magnesium ions. The concentration of these ions is typically referred to as water hardness. The hardness of tap water depends on various factors, including water treatment and geological conditions. Tap water hardness can fluctuate over time and can even change within a single day.

[0003] Water hardness has a negative impact on household appliances that use water. For example, it reduces the effectiveness of detergents and / or dishwashing liquids. Water hardness can also cause limescale buildup in household appliances, which can significantly shorten their lifespan.

[0004] There are technical ways to reduce water hardness and thus eliminate its negative effects. Ion exchangers are commonly used, which remove at least some of the ions from the incoming water. These ion exchangers require regular regeneration, which can be achieved, for example, by flushing them with a regeneration solution. The regeneration solution is regularly supplied within the water-using appliance itself by dissolving regeneration salt. This process consumes the regeneration salt, which has two disadvantages: firstly, the regeneration salt must be replenished regularly, and secondly, it results in an increased release of chemically active substances into the wastewater. Regular refilling of the regeneration salt leads to higher operating costs for the water-using appliance and is an inconvenient refilling process for the user.The introduction of chemically active substances into wastewater can have a negative impact on the environment.

[0005] Jonathan Filley, Mohamed A. Ibrahim, Mark R. Nimlos, Andrew S. Watt, Daniel M. Blake: Magnesium and calcium chelation by a bis-spiropyran, Journal of Photochemistry and Photobiology A: Chemistry, Vol. 117, Issue 3, 15 Sept. 1998, pages 193-198, DOI: 10.1016 / S1010-6030(98)00346-3 describes the chelation of magnesium and calcium using bis-spiropyran.

[0006] Peter Gründler: Chemical Sensors - An Introduction for Natural Scientists and Engineers, Springer Verlag 2004, Section 2.3.3 “Surface Modification and Ordered Monolayers”, Section 90, deals with surface modification and ordered monolayers and in particular with the immobilization of functional molecules.

[0007] Photoreversible ion-binding using spiropyran-modified silica microbreads is known from Scarmagnani, Silvia, et al. Photoreversible ion-binding using spiropyran-modified silica microbreads, International Journal of Nanomanufacturing, 2009, Vol. 5, No. 1-2, pp. 38-52; DOI: 10.1504 / IJNM.2010.029921.

[0008] Zanoni, Michele et al., A novel spiropyran-conducting polymer biosensor chip with electrochemical and photochemical sensing properties, 2013, p. 889-891, describes a novel spiropyran-conducting polymer biosensor chip with electrochemical and photochemical sensor properties.

[0009] The fabrication of spiropyran-containing thin-film sensors for the simultaneous identification of multiple metal ions is known from Fries, Kirsten et al., Fabrication of spiropyran-containing thin film sensors used for the simultaneous identification of multiple metal ions, Langmuir, 2011, 27th year, no. 19, pp. 12253-12260.

[0010] Against this background, one object of the present invention is to provide an improved water softening device.

[0011] According to a first aspect, a water softening device for a household appliance is proposed. The household appliance in question is, in particular, a dishwasher. The water softening device is designed to soften the water supplied to the appliance. For this purpose, the water softening device includes a means for fixing activatable molecules. The activatable molecules have an activated state, a deactivated state, and a complexed state. In the activated state, the molecules are capable of transitioning from the activated state to the complexed state by forming complexes with ions dissolved in the water. Furthermore, the water softening device includes an activation mechanism designed to bring the activatable molecules into the activated state.

[0012] Such a water softening system has the advantage that no consumables are required for softening the water. Because the activatable molecules are fixed in the fixing agent and can be activated by an energy input from the activation unit, these molecules are not consumed during the softening process. Therefore, such a water softening system can contribute to saving raw materials and thus also to reducing costs.

[0013] Water hardness is primarily defined by the concentration of metal ions in the water. Calcium and magnesium ions, in particular, are decisive factors in determining the water hardness value. The water hardness of drinking water, for example, depends on both the geological conditions of a region and any water treatment processes. In Germany, for instance, water hardness is usually below 30° dH (German hardness). 1° dH corresponds to an alkaline earth ion concentration of approximately 5.6 µmol / l. A rough classification of water hardness can be made as follows: a hardness range of up to 7.3° dH is considered soft; a hardness range of 7.3° to 14° dH is considered medium-hard; a hardness range of 14° to 21.2° dH is considered hard; and a hardness range above 21.3° dH is considered very hard.

[0014] An agent for immobilizing activatable molecules is, for example, a substance with which an activatable molecule can form a chemical bond, thus binding the activatable molecule to the substance. In this context, a chemical bond is understood to be any interaction that results in the molecule remaining within the agent. This includes covalent bonds, ionic bonds, metallic bonds, hydrogen bonds, dipole-dipole bonds, van der Waals bonds, electrostatic interactions, and / or specific interactions such as coordination. Other methods of immobilization are also conceivable. For example, it is possible to introduce the activatable molecules into the agent, such as by diffusion and / or implantation, so that the activatable molecules are trapped within the agent without forming a chemical bond with it.Furthermore, the agent may also contain a binding agent which in turn has a bond to the agent and enables a bond to the molecule.

[0015] The activatable molecules, hereinafter referred to simply as molecules, are in an activated state. In this activated state, the molecules have a high affinity for ions dissolved in the water, particularly calcium and / or magnesium ions. High affinity means that they exhibit a strong interaction, such as electrostatic interaction, with the ions, causing the ions to bind to the molecule. When an ion is bound to an activatable molecule, the molecule is in a complexed state. The complexed state thus comprises both the activatable molecule and the bound ion, which is hereinafter referred to simply as a complex. In the complexed state, there is a strong interaction between the molecule and the ion. It is also possible for an activatable molecule to form a bond with more than one ion.The complexed state then describes the state in which the molecule binds the maximum number of ions. If such a molecule does not bind the maximum number of ions, it can be described as a partially complexed state. A complex, in particular, exhibits no or only weak interaction with other ions. Complex formation can also be described as trapping, chelation, electrostatic interaction, and / or ionic bonding. In contrast, in the deactivated state, the activatable molecules have a low affinity for ions dissolved in the water. This means that ions dissolved in the water do not interact, or only weakly, with the molecules in the deactivated state and therefore do not form bonds with them, remaining mobile in the water.

[0016] The activatable molecules preferably comprise a large number of atoms, for example, carbon chains and / or carbon rings. Furthermore, they may possess inorganic side groups. The activatable molecules exhibit, in particular, a plurality of eigenstates. Depending on the eigenstate, the activatable molecules exhibit either a high or a low affinity for ions dissolved in the water. By means of a suitable energy input, the activatable molecules can be switched between different eigenstates.

[0017] Activable molecules include ionophores, particularly chromoionophores, thermoionophores, electroionophores, and / or solvatoionophores. Spiropyrans are one example. Spiropyran is the deactivated form. For example, irradiation with UV light at a wavelength in the range of 250–380 nm can convert it into merocyanine, which is the activated form. Irradiation with light at a wavelength in the visible range can convert this back into spiropyran.

[0018] According to one embodiment of the water softening device, the activation device includes an activation agent. The activation agent is designed to bring the activatable molecules from the deactivated state to the activated state.

[0019] The activated state is characterized in particular by the high affinity of the molecules for ions dissolved in the water. In the activated state, for example, unshielded or only weakly shielded charges are present on a surface of the molecule. This leads, for instance, to a strong electrostatic interaction of the molecules with the ions dissolved in the water, causing the ions to remain attached to the molecule, immobilized there, and thus removed from the water.

[0020] The activation agent is, in particular, a device designed to transfer a suitable amount of energy to the molecules. The suitable amount of energy is, for example, the energy required to transition the molecules from a first eigenstate, corresponding to the deactivated state, to a second eigenstate, corresponding to the activated state. Such an energy input can, for example, change a chemical bond in the molecule and / or the orientation of a group within the molecule.

[0021] The activation agent includes, for example, an irradiation device, a heating device, an electrochemical device and / or a chemically active substance.

[0022] According to another embodiment of the water softening device, the activation device includes a deactivating agent. The deactivating agent is designed to bring the molecules from the activated state and / or the complexed state into the deactivated state.

[0023] The deactivating agent is, for example, a device configured to transfer a suitable amount of energy to the molecules, causing them to transition from the activated state to the deactivated state. The energy input can also cause the molecules to transition from the complexed state to the deactivated state. The deactivating agent can be configured, in particular, to induce different state changes. When the molecules are transitioned from the complexed state to the deactivated state, this involves the interruption of the strong interaction between the molecules and the ion. The ions, however, remain localized to the deactivated molecule. The interaction is then only weak. Weak means, for example, that the interaction energy between the ion and the molecule is lower than the thermal energy of the ion at room temperature.In their deactivated state, the molecules exhibit a low affinity for ions dissolved in the water. In particular, the molecules can no longer form complexes.

[0024] The deactivating agent includes, for example, an irradiation device, a heating device, an electrochemical device and / or a chemically active substance.

[0025] According to another embodiment of the water softening device, the activation device includes a rinsing device. The rinsing device is designed to remove ions from the molecules in the deactivated state.

[0026] The rinsing device contains, for example, a liquid. Preferably, the liquid has a high dielectric constant, such as water. Since the ions are only weakly bound to the molecules in the deactivated state, they are solvated in the liquid. This results in a very high concentration of dissolved ions in the area of ​​the agent containing the fixed activatable molecules. A very high ion concentration can, for example, cause the ions to form insoluble complexes with other molecules in the liquid. These insoluble complexes precipitate out of the liquid. Such precipitates can, for example, be filtered out and disposed of as a solid and / or further processed.

[0027] The rinsing device can also effect the mechanical removal of weakly bound ions. For example, the molecules containing the weakly bound ions are brought into physical contact with a designated surface of the rinsing device. This surface can, for instance, have groups that have a high affinity for the ions, causing the ions to preferentially bind to these groups and thus be removed from the deactivated molecules.

[0028] According to another embodiment of the water softening device, the activation agent is designed as an electromagnetic radiation source. This includes, in particular, a laser, a UV light-emitting diode, a microwave generator, and / or a radio wave source. Furthermore, the activation agent can be designed as a chemically active fluid, such as an acid, as an electrochemically active device, an electrically active device with a voltage source, such as a capacitor, and / or as a heat source.

[0029] The activating agent is selected depending on the molecules to be activated. For example, a laser might be a suitable activating agent for one type of molecule, while an infrared radiation source might be suitable for another. The activating agent is specifically designed to provide the molecules with activation energy, enabling them to transition to the activated state.

[0030] According to another embodiment of the water softening device, the deactivating agent comprises an electromagnetic radiation source, such as a laser, a UV light-emitting diode, a microwave generator, an infrared radiation source, and / or a radio radiation source. Furthermore, the deactivating agent may comprise a chemically active fluid, such as an acid, an electrochemically active device, a capacitor with a voltage source, and / or a heating source.

[0031] According to another embodiment of the water softening device, the rinsing device comprises a liquid bath containing a rinsing liquid.

[0032] The rinsing solution is particularly suitable for removing weakly bound ions from the molecules, for example by solvating the ions and subsequently dissolving them in the rinsing solution. The rinsing solution is, for example, water and / or water with a proportion of a chemically active substance, such as a surfactant.

[0033] According to the invention, the water softening device has a treatment chamber in which the agent for fixing the activatable molecules can be brought into contact with the water.

[0034] Preferably, the treatment chamber is designed to allow a continuous flow of water. This ensures that fresh, softened water is always available to the water-using household appliance. Alternatively, the treatment chamber can be configured to prevent a continuous flow of water, providing the softened water in batches.

[0035] According to another embodiment of the softening device, the means for fixing the activatable molecules is designed as an organic film, a hydrogel, a polymer network, a porous inorganic substrate, such as a metallic substrate, a glass substrate, a ceramic substrate and / or an oxide substrate, a nanoparticle and / or as a textile.

[0036] Suitable agents have a particularly large surface area to bind a large number of activatable molecules to the surface. Preferably, the activatable molecules are located on or at the surface of the agent. Furthermore, the agent is designed to provide water with access to the activatable molecules. For example, a hydrogel preferably exhibits good swelling properties. This allows water to penetrate the hydrogel, and the ions can then interact with the activatable molecules.

[0037] The agent can be flexible and / or hard or rigid. Furthermore, it can be designed to form a layer on a substrate, with the substrate then ensuring, for example, mechanical integrity. The agent and / or the substrate can also perform other functions; for instance, they can be conductive and used as an anode during electrochemical activation and / or deactivation of the molecules. They can also exhibit good thermal conductivity, making them suitable for thermal activation and / or deactivation of the molecules. Particularly with photoactivatable molecules, it is advantageous if the agent and / or the substrate is not completely absorbing at the wavelengths used for activation and / or deactivation.This means that the absorption coefficient and / or extinction coefficient of the material must be sufficiently small. In particular, it depends on the path length of the light within the material, which is what "sufficiently small" means. The path length is, for example, the distance the radiation must travel through the material before it encounters an activatable molecule. For instance, a condition could be that at least 1% of the original radiation intensity remains after a path length of 1 mm.

[0038] According to another embodiment of the water softening device, the activatable molecules are spiropyrans.

[0039] Spiropyrans exhibit two states: the deactivated state is called spiropyran, and the activated state is called merocyanine. Spiropyran can be activated by an activating agent, and merocyanine can be deactivated by an activating agent. Merocyanine can also form complexes with ions.

[0040] According to a further embodiment of the water softening device, the means for fixing the activatable molecules is designed as a circumferential, flexible film, wherein the film is movable along a circumferential direction by means of a transport device. The activating agent, the treatment chamber, the deactivating agent, and the rinsing device are arranged along a path along the circumferential film.

[0041] Such a water softening device has the advantage that, by simply transporting the film along the direction of circulation, the activatable molecules are sequentially activated, complexed, deactivated, and finally purified. This allows for continuous operation of the water softening device.

[0042] According to a second aspect, a water-bearing household appliance with a water softening device according to the first aspect is proposed.

[0043] The water-bearing household appliance is in particular a dishwasher, a washing machine, a coffee machine, a kettle, an iron and / or a steam cooker.

[0044] The embodiments of the first aspect also represent embodiments of the second aspect.

[0045] According to a third aspect, a method for operating a water softening device is proposed. The method comprises the following steps: activating activatable molecules, wherein the activatable molecules have an activated state, a deactivated state, and a complexed state, the molecules in the activated state being configured to transition from the activated state to the complexed state by forming complexes with ions dissolved in water; bringing water into contact with the activatable molecules in the activated state; deactivating the activatable molecules and removing ions from the activatable molecules in the deactivated state.

[0046] Such a process advantageously allows water to be softened without consuming consumables.

[0047] For example, the proposed method is carried out with one of the embodiments of the water softening device according to the first aspect. In particular, the proposed method can also be carried out as part of a control program for a water-bearing household appliance according to the second aspect.

[0048] The embodiments and features described for the proposed device apply accordingly to the proposed method.

[0049] Other possible implementations of the invention also include combinations of features or embodiments described previously or subsequently with regard to the exemplary embodiments, even if not explicitly mentioned. In such cases, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the invention.

[0050] Further advantageous embodiments and aspects of the invention are the subject of the dependent claims and the exemplary embodiments of the invention described below. The invention will be explained in more detail below with reference to preferred embodiments and the accompanying figures. Fig. Figure 1 shows a schematic representation of a water-bearing household appliance with a water softening device; Fig. Figure 2 shows an example of a sequence of different states of the activatable molecules in a circulation diagram; Fig. Figures 3A - 3C show various embodiments of how the different states of the molecules can be achieved; Fig. Figure 4 shows an embodiment of a water softening device with a circumferential film and continuous operation capability; and Fig. Figure 5 shows an embodiment of a method for operating a water softening device.

[0051] In the figures, identical or functionally equivalent elements have been given the same reference symbols, unless otherwise indicated.

[0052] In Fig. Figure 1 shows a perspective view of a first embodiment of a water-bearing household appliance 1. In the example of the Fig. 1 is the water-carrying household appliance 1 a dishwasher 1 which is equipped with a water softening device 100 arranged in its base.

[0053] Dishwasher 1 has a body comprising a wash tub 2 and a door 3. The wash tub 2 and the door 3 form a wash chamber 4 for washing dishes. The door 3 is in Fig. 1 is shown in its open position. By pivoting about a pivot axis S provided at a lower end of the door 3, the door 3 can be closed or opened.

[0054] The washing container 2, for example, is cuboid in shape and can comprise a base 5, a top 6 opposite the base 5, a back wall 7 opposite the door 3, and two opposing side walls 8, 9. In particular, the side walls 8, 9 can be made of stainless steel sheet.

[0055] The dishwasher 1 further comprises at least one loading level 10. This at least one loading level 10 is preferably a dish loading area of ​​the dishwasher 1. In particular, several loading levels 10 can be provided, which may include a lower basket, an upper basket, and / or a cutlery drawer. The several loading levels 10 are preferably arranged one above the other in the wash tub 2. Each loading level 10 can be selectively moved either in an insertion direction E into the wash tub 2 or in an extension direction A out of it. For this purpose, a rail 11 is preferably provided on both sides of each loading level 10.

[0056] A control device 12, optionally provided in the body or in the door 3 of the dishwasher 1, is designed, among other things, to control the sequence of washing programs for washing items. Furthermore, the control device 12 can control other controllable units, in particular the water softening unit 100.

[0057] For example, dishwasher 1 can be a freestanding, an integrated or a fully integrated dishwasher 1.

[0058] The water softening device 100 includes a means 120 for fixing activatable molecules 130 (see Fig. 2 - 4) and an activation device 150 and is in particular designed to measure the water 110 supplied to a rinsing liquor (see Fig. 3A - 3C) to soften the water, i.e., to reduce the hardness of the water 110 to a predetermined value. For example, the water 110 has a hardness of 20° German hardness (dH). One degree of German hardness (1°dH) corresponds approximately to an alkaline earth ion concentration of 5.6 µmol / L. The water softening device 100 is then configured to reduce the hardness of the water 110 to 5°dH by adding ions 140 to the water 110 (see Fig. 2 - 4), in particular calcium ions and / or magnesium ions. The water softening device 100 achieves this, in particular, without consuming any consumable material that would need to be regularly refilled. An embodiment of a water softening device 100 is shown in the Fig. Figure 4 shows the operation of the water softener 100. The functionality of this unit will now be explained using the following: Fig. 2 explained.

[0059] Fig. Figure 2 shows an example of a sequence of different states 131, 132, 132', 133 of an activatable molecule 130 in a cycle 200. Initially, the molecule 130 is in the deactivated state 132. For example, the molecule 130 in the deactivated state 132 is a spiropyran 132. By irradiating the spiropyran 132 with UV radiation 151, the state changes to the activated state 131, which is also called merocyanin 131. Thus, the UV radiation 151 acts as an activating agent. The merocyanin 131 is capable of forming a complex 133 with an ion 140. This process occurs automatically as soon as the merocyanin 131 comes into contact with water 110 in which an ion 140 is dissolved, and the ion 140 comes close to the merocyanin 131. The ion 140 is mobile in the water 110 and is attracted to the merocyanin 131, as indicated in the diagram by the dashed arrow 141.When ion 140 comes into contact with merocyanine 131, the merocyanine 131 forms a complex 133 with ion 140. "Coming into contact" in this context means that ion 140 gets so close to merocyanine 131 that a positive interaction between merocyanine 131 and ion 140 exceeds the thermal energy of ion 140, causing ion 140 to bind to and be immobilized by merocyanine 131. Complex 133 therefore comprises merocyanine 131 and ion 140. This complexed state 133 is stable in water 110, meaning that ion 140 does not spontaneously detach from merocyanine 131. For example, by irradiating complex 133 with a laser 152, the intrinsic state of merocyanine 131 changes, and it switches back to the spiropyran form 132, with ion 140 initially remaining with spiropyran 132, which is indicated as a transition state 132'. Thus, the laser 152 acts as a deactivating agent.In this state 132', there is no or only a weak attractive interaction with ion 140. Ion 140 can be easily removed. This can be done, for example, with a rinsing solution 154 by bringing the molecule in state 132' into contact with the rinsing solution 154. Ion 140 dissolves in the rinsing solution 154 and is thus removed from the spiropyran 132. Cycle 200 can then begin again.

[0060] Fig. 3A shows a first embodiment of the based on Fig. Cycle 200 described. In the Fig. Figure 3A shows four different operating states I, II, III, and IV side by side. For clarity, the reference symbols for each element are shown only once. Each operating state I, II, III, and IV shows the activatable molecule 130, fixed to the surface of a medium 120, in different states 131, 132, 132', and 133. The medium 120 is, for example, configured as an organic substrate 120.

[0061] Operating state I shows molecule 130 with ion 140 in the complexed state 133. In operating state II, substrate 120 with complex 133 was introduced into a rinsing liquid 154. A laser 310 is also shown, irradiating complex 133 with a laser beam 311, causing molecule 130 to transition to the deactivated state 132', in which ion 140 is only weakly bound to molecule 130. Simultaneously, ion 140 is removed from molecule 130, as molecule 132' is located in the rinsing liquid 154. The deactivated molecule 132 therefore remains. In operating state III, the deactivated molecule 132 is activated by irradiation with UV radiation 321 using a UV LED 320. Finally, in operating state IV, the activated molecule 131 is brought into contact with the water 110, and an ion 140 is "captured" by the molecule. A complex 133 is formed, as already described in operating state I.

[0062] Fig. 3B shows a second embodiment of the based on Fig. Cycle 200 described. As already mentioned in Fig. Figure 3A shows four different operating states I, II, III, IV. For clarity, the reference symbols for each element are shown only once. Each operating state I, II, III, IV shows the activatable molecule 130, fixed to the surface of a medium 120, in different states 131, 132, 132', 133. The medium 120 is, for example, configured as an organic substrate 120.

[0063] In operating state I, a complex 133 between molecule 130 and ion 140 is shown. In operating state II, the substrate 120 with the fixed molecule 130, which exists as complex 133, was transferred to a rinsing liquid 154, where it was simultaneously irradiated with UV radiation 321 from a UV LED 320. The irradiation 321 deactivates molecule 130 132', and the now only weakly bound ion 140 dissolves in the rinsing liquid 154. Thus, the deactivated molecule 132 remains. In operating state III, the substrate 120 with the fixed deactivated molecule 132 was placed in an acid bath 330. The acid 330 reacts with the deactivated molecule 132, thereby converting it to the activated state 131. In operating state IV, the substrate 120 with the fixed activated molecules 131 is again in contact with water 110, whereby ions 140 are removed from the water 110 and the water 110 is thus softened.

[0064] In this embodiment, the activatable molecule 130 is deactivated with UV radiation and activated with acid 330.

[0065] Fig. 3C shows a third embodiment of the based on Fig. 2 described cycle 200. As already mentioned in the Fig. 3A and Fig. Figure 3B shows four different operating states I, II, III, IV. For clarity, the reference symbols for each element are shown only once. Each operating state I, II, III, IV shows the activatable molecule 130, fixed to the surface of a substance 120, in different states 131, 132, 132', 133. The substance 120 is, for example, configured as an organic substrate 120.

[0066] In operating state I, the substrate 120 with the fixed molecule 130 is arranged in water 110. The molecule 130 is in the deactivated state 132. A dissolved ion 140 is present in the water 110. Since the molecule 132 is deactivated, no reaction takes place between the molecule 130 and the ion 140. In operating state II, a UV LED 320 is additionally shown, which irradiates the molecule 130 with UV radiation 321. This brings the molecule 130 into the activated state 131. Therefore, a reaction can now take place between the ion 140 and the molecule 130, which is why the molecule 130 transitions into the complexed state 133 with the ion 140. In the third operating state III, the complex 133 continues to be irradiated with UV radiation 321, which is why the complex 133 is maintained. In the fourth operating state IV, the UV LED 320 was switched off, which is why the molecule 130 relaxed itself from the complexed state 133 to the deactivated state 132.The ion 140 therefore dissolves again in the water 110.

[0067] In this embodiment, the activatable molecule 130 is only able to form a complex 133 with an ion 140 as long as it is irradiated by the UV radiation 321.

[0068] Fig. Figure 4 shows an embodiment of a water softening device 100 with a circumferential film 120 as the means for fixing 120. Fig. Figure 4 shows an activation agent 151, a deactivation agent 152, a rinsing device 153, and a treatment chamber 160. The activation agent 151, the deactivation agent 152, and the rinsing device 153 together form the activation device 150. Transport devices 170 are also shown, which are designed here as rollers 170 that can transport the film 120 in the direction of rotation 171 by means of a uniform direction of rotation. The film 120 has activatable molecules 130 fixed to its surface.

[0069] The activation agent 151 includes, for example, a UV LED 320 (see Fig. 3A, Fig. 3C). The foil 120 is conveyed through the activating agent 151 by the rotation of the rollers 170. This process activates the molecules 130 into the activated state 131. The foil 120 is then transported through the treatment chamber 160. The water 110, which is to be softened, is located in the treatment chamber 160. For this purpose, the foil 120 with the activated molecules 131 is brought into contact with the water 110 in the treatment chamber 160. This causes complexes 133 to form between the ions 140 dissolved in the water 110 and the activated molecules 131. The ions 140 are thereby removed from the water 110.

[0070] The foil 120 is then fed to the deactivating agent 152, which here, for example, deactivates a laser 310 (see Fig. 3A). By irradiating the complexes 133 with the laser beam 311, the molecules 130 are converted into the deactivated state 132'. The foil 120 with the deactivated molecules 132' and the ions 140 is then fed to the rinsing device 153. There, the deactivated molecules 132' and the ions 140 are brought into contact with a rinsing liquid 154, for example, water 154. The ions 140 are dissolved in the water 154 and thus removed from the deactivated molecules 132. The deactivated molecules 132 are then fed to the activation agent 151 to be reactivated 131.

[0071] By transporting the surrounding foil 120 from the rollers 170, continuous operation of the softening device 100 is made possible.

[0072] Fig. Figure 5 shows an embodiment of a method for operating a water softening device 100. The method can be used, for example, with the water softening device 100 of the Fig. 4. The procedure comprises the four steps Activating S1, Bringing into contact S2, Deactivating S3, and Removing S4, which are explained in detail below. Steps S2, S3, and S4 are, in particular, as described in one of the embodiments of the Fig. 3A - 3C feasible.

[0073] Activating the activatable molecules 130 (S1) is suitable for bringing them into the activated state 131. For this purpose, the molecules 130 are treated with an activating agent 151, such as UV radiation 321 or acid 330.

[0074] Bringing the activated molecules 131 into contact with the water 110 to be softened involves, for example, immersing the agent 120 containing fixed activatable molecules 130 in their activated state 131 in a specially prepared basin. Alternatively, the activatable molecules 130 may be arranged on the inside of a water pipe, and the water 110 may be passed through this pipe (not shown). In this process, the water 110 comes into contact with the activated molecules 131, forming complexes 133 with ions 140 dissolved in the water 110, thereby softening the water 110.

[0075] The deactivation S3 of the activated 131 and / or complexed 133 molecules 130 comprises, in particular, a deactivating agent 152, which is suitable for converting the molecules 130 from the activated state 131 and / or the complexed state 133 to the deactivated state 132 and / or the deactivated state with associated ion 132'. The deactivating agent 152 can, for example, be configured as a UV LED 320 and / or a laser 310.

[0076] The removal of the ions 140 from the deactivated molecules 133 can be achieved, for example, with a suitable rinsing fluid 154. A suitable rinsing fluid 154 is, for example, water in which the ions 140 become concentrated. The rinsing fluid 154 enriched with ions 140 can, for example, be regenerated or drained away. The ions 140 can also be removed, for example, by electrostatic forces or by mechanical action, such as by brushing the surface of the medium 120 with the fixed molecules 130 (not shown). In this case, a brush used for brushing can be electrostatically charged to bind the ions 140.

[0077] Although the present invention has been described with reference to exemplary embodiments, it can be modified in many ways. In addition to the activation means 151 and / or deactivation means 152 shown, further means are conceivable. In particular, these include infrared radiation, microwave radiation, and radio radiation with their respective generating devices. Reference symbols used: 1 water-bearing household appliance 2 washing containers 3 Door 4 wash chambers 5 Floor 6 Ceiling 7 Back panel 8 side wall 9 side wall 10 Loading level 11 rail 12 Control device 100 Water softener 110 water 120 fixing agents 130 activatable molecules 131 activated state (also: activated molecule) 132 deactivated state (also: deactivated molecule) 132' deactivated state with weakly bound ion 133 complex state (also: complex) 140 ions 141 Direction of movement (of an ion) 150 Activation device 151 activating agents 152 deactivating agents 153 Flushing device 154 Rinsing fluid 160 Treatment chamber 170 Transport equipment 171 Direction of rotation 200 cycle 310 Laser 311 Laser beam 320 UV light-emitting diode 321 UV light 330 acid A Extraction direction E Insertion direction I Operating state II Operating state III Operating state IV Operating state S axis S1 Procedure Step (Activate) S2 Procedure Step (bringing into contact) S3 Procedure Step (Deactivate) S4 Procedure Step (Remove)

Claims

[1] Water softening device (100) for a water-bearing household appliance (1), in particular a dishwasher, for softening water (110) supplied to the household appliance (1), comprising an agent (120) for fixing activatable molecules (130), wherein the activatable molecules (130) have an activated state (131), a deactivated state (132) and a complexed state (133), wherein the molecules (130) in the activated state (131) are configured to transition from the activated state (131) to the complexed state (133) by forming complexes with ions (140) dissolved in water (110), and an activation device (150) configured to bring the activatable molecules (130) into the activated state (131), and a treatment chamber (160) in which the agent (120) is used for fixing the activatable molecules (130) can be brought into contact with the water (110). [2] Softening device according to claim 1, wherein the activation device (150) comprises an activation agent (151) which is configured to bring molecules (130) from the deactivated state (132) to the activated state (131). [3] Softening device according to claim 1 or 2, wherein the activation device (150) comprises a deactivation agent (152) which is configured to bring molecules (130) from the activated state (131) and / or the complexed state (133) into the deactivated state (132). [4] Softening device according to claim 3, wherein the activation device (150) comprises a rinsing device (153) which is configured to remove ions (140) from molecules (130) in the deactivated state (132). [5] Water softening device according to one of claims 2 to 4, wherein the activating agent (151) comprises an electromagnetic radiation source, in particular a laser, a UV light-emitting diode, a microwave generator, an infrared radiation source and / or a radio radiation source, a chemically active fluid, in particular an acid, an electrochemically active device, a capacitor with a voltage source and / or a heating source. [6] Water softening device according to one of claims 3 to 5, wherein the deactivating agent (152) comprises an electromagnetic radiation source, in particular a laser, a UV light-emitting diode, a microwave generator, an infrared radiation source and / or a radio radiation source, a chemically active fluid, in particular an acid, an electrochemically active device, a capacitor with a voltage source and / or a heating source. [7] Softening device according to one of claims 4 to 6, wherein the rinsing device (153) comprises a liquid bath. [8] Softening device according to one of claims 1 to 7, wherein the means (120) for fixing the activatable molecules (130) comprises an organic film, a hydrogel, a polymer network, a porous inorganic substrate, in particular a metallic substrate, a glass substrate, a ceramic substrate and / or an oxide substrate, nanoparticles, and / or textiles. [9] Water softening device according to any one of claims 1 to 8, wherein the activatable molecules (130) in their deactivated state (132) are a spiropyran and in their activated state (131) are a merocyanin. [10] Softening device according to one of claims 1 to 9, wherein the means (120) for fixing the activatable molecules (130) is designed as a circumferential, flexible film (120), wherein the film (120) is movable along a circumferential direction (171) by means of a transport device (170), wherein the activating agent (151), the treatment chamber (160), the deactivating agent (152) and the rinsing device (153) are arranged along a path along the circumferential film (120). [11] Water-bearing household appliance (200) with a water softening device (100) according to one of claims 1 to 10. [12] Method for operating a water softening device (100) for softening water (110) according to any one of claims 1-10, comprising: Activation (S1) of the activatable molecules (130), wherein the activatable molecules (130) have an activated state (131), a deactivated state (132) and a complexed state (133), wherein the molecules (130) in the activated state (131) are configured to transition from the activated state (131) to the complexed state (133) by forming complexes with ions (140) dissolved in water (110), Bringing the water (110) into contact (S2) with the agent (120) for fixing the activatable molecules (130), Deactivation (S3) of the activatable molecules (130), and Removal (S4) of ions (140) from the activatable molecules (130) in the deactivated state (132).

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