Patent Application
20240309577
The disclosure relates to a water-conducting electrical device and to a method for operating a water-conducting electrical device. In particular, the disclosure relates to a water-conducting electrical device having an electrochemical cell designed to produce a bleaching agent in situ, and to a method for operating the water-conducting electrical device. For the sake of simplicity, the water-conducting electrical device is also referred to below as a device.
Bleaching agents, such as hydrogen peroxide, have a good cleaning effect, but in solutions are only stable to a limited extent and storable to a limited extent. There is therefore a need to produce such a bleaching agent in situ prior to use in the water-conducting electrical device if objects located therein are to be cleaned.
A water-conducting electrical device in the form of a washing machine which contains an electrochemical cell in order to produce a bleaching agent during a washing process is known from prior art not documented in print. However, the problem is that the integration of the electrochemical cell requires installation space, which is present only to a limited extent in water-conducting electrical devices and, moreover, increases production costs. It would therefore be advantageous to save upon installation space and costs.
The disclosure has an object of providing a water-conducting electrical device and a method for operating a water-conducting electrical device that are cost-effective and require little installation space.
According to the disclosure, this object is achieved by a water-conducting electrical device and method having the features of the independent claims. Advantageous embodiments and developments of the disclosure can be found in the following dependent claims.
In addition to cost-effectiveness, the advantages that can be achieved with the disclosure are that the electrochemical cell serves not only to produce the bleaching agent but also as a heating device. The electrochemical cell thus fulfills several functions. As a result, the device does not require a separate and additional heating device, so that the component, which is usually present in such devices, is saved upon. This saves upon installation space and costs.
The disclosure relates to a water-conducting electrical device having
The device has a relatively low complexity, and the used installation space is relatively small because, in addition to the application or function of producing the bleaching agent when DC voltage is applied, the electrochemical cell also simultaneously carries out the application or function of a heating device when AC voltage is applied. That is to say, via one component, viz., the electrochemical cell, the functions of both the production of the bleaching agent, such as hydrogen peroxide, and the heating of fluid located in the electrochemical cell, as well as the production of steam from an aqueous solution, are realised. The heating power of the electrochemical cell can be controlled by the composition located in it and possibly by a quantity of water furthermore added thereto, while a standard heating device has a fixed heating power. For example, the device can be programmed for various power supplies. An adaptation as a function of a quantity of current located in the mains is also possible. The device can thus be part of a smart power grid, also referred to as a smart grid. Moreover, standard heating devices in water-conducting devices calcify over time, while calcification of the electrochemical cell is prevented or at least minimised by rinsing.
In a preferred embodiment, the control unit has a relay designed to switch from DC to AC voltage and vice versa. The control unit preferably has control electronics. Preferably, the application of the DC or AC voltage is controlled by means of the control electronics of the control unit. The geometry with different electronic control further reduces the installation space and costs.
Preferably, the control unit furthermore has a rotary relay designed to connect a grounded N conductor to an electrode of the electrochemical cell that is arranged at an inlet and an outlet of the electrochemical cell. The rotary relay can preferably be controlled by the control electronics such that the line with low voltage against ground (N potential) can be connected to the electrode of the electrochemical cell that is arranged at the inlet and outlet of the electrochemical cell. This ensures that only small leakage currents can flow through the water during operation. This increases the operational safety of the device. The electrode of the electrochemical cell that is arranged at the inlet and outlet of the electrochemical cell is preferably the anode.
The control unit preferably has a protective ground which is designed in such a way that a polarity of the supply voltage can be determined. The polarity of the supply voltage can preferably be determined by the control electronics. Preferably, a mains voltage, which is usually AC voltage, is fed to the control electronics and serves to supply voltage. In order to produce the bleaching agent, a DC voltage—preferably a low DC voltage—is produced from the mains voltage and can be applied by the control electronics to the cathode and anode as the electrodes of the electrochemical cell.
The control electronics is preferably designed to appropriately control the rotary relay for heating the fluid in the electrochemical cell, so that AC voltage is provided, and then to use the relay to switch on heating. In this case, the anode potential is fed back to the control electronics. The control electronics are furthermore designed to switch off heating when a critical voltage occurs at the anode against the ground potential of the protective conductor.
The salt-containing solution can contain one or more salts that is or are designed to increase the conductivity of water. In a preferred embodiment, the device contains a metering unit designed to meter the salt-containing solution into the electrochemical cell. The metering unit can furthermore be designed to meter a washing agent into the electrochemical cell. This is in particular advantageous if the bleaching agent is used not only to clean a device interior of the device, but also to clean objects located in the device interior. For example, the device is a washing machine, and the objects are textiles in the form of laundry to be washed. The washing agent can be a washing agent that is usually used for washing or for laundry to be treated, such as a heavy-duty detergent, mild detergent, fabric softener, stain remover, cleaning agent, etc. The metering unit can have several chambers in order to meter various washing agents into the electrochemical cell at the same time or at intervals. The metering unit preferably has a metering pump designed to pump the salt-containing solution and/or the washing agent from the metering unit into the electrochemical cell. The washing agent may constitute the salt-containing solution, which then furthermore contains active washing substances in addition to the salt.
In a preferred embodiment, the device furthermore has a recirculation system for conducting water from a first region of the water receiving element into a second region of the water receiving element, wherein the recirculation system has, as the pump, a recirculation pump designed to pump water out of the first region through the electrochemical cell into the second region. As a result, the bleaching agent produced in the electrochemical cell can be conveyed in the circuit through the water receiving element and the electrochemical cell.
Position and direction information relates to an operational set-up position of the device. The first region of the water receiving element is preferably a lower region, and the second region of the water receiving element is preferably an upper region.
Preferably, an inlet and an outlet of the electrochemical cell are arranged on an upper part of the electrochemical cell, wherein the inlet is connected to the pump, and the outlet is connected to a line designed to feed fluid, conducted through it, to the water receiving element, such as the second region of the water receiving element.
In a preferred embodiment, the electrochemical cell is connected via an outlet valve to a point of a water line system that is fluidically arranged upstream of an outlet pump designed to discharge water from the device. This provides a simple possibility for cleaning the electrochemical cell. This makes it possible to flush the electrochemical cell and to remove the water flushed through the electrochemical cell from the water line system and the device. As a result, the electrochemical cell can be freed of lime sludge and dirt. For this purpose, the outlet valve is opened, and the water flowing out of the electrochemical cell is discharged by means of the outlet pump. Ideally, the pumping out is combined with a pumping out in a cleaning process performed by the device. The water line system may be the recirculation system.
The water-conducting electrical device can preferably be connected to a water connection, and the control unit is configured to automatically control a water supply from the water connection into the water receiving element-preferably into the first region. Between the water connection and the water receiving element, the device preferably has a controllable valve and a feed line.
The water-conducting electrical device is, for example, a domestic appliance which is used commercially or privately. The device is preferably a washing machine, a dishwasher, a coffee machine, or a steam cooker. Depending upon the type of device, the produced bleaching agent can serve exclusively for cleaning the device interior or, alternatively or additionally, for cleaning objects located in the device interior.
In a preferred embodiment, the water-conducting electrical device is designed as a washing machine, and the water receiving element is designed as a suds container.
The bleaching agent produced is preferably peracetic acid or hydrogen peroxide. More preferably, the bleaching agent produced is hydrogen peroxide. Preferably, a cell size of the electrochemical cell is designed for a quantity of the bleaching agent required in a cleaning process. The cathode and anode surfaces are each 10 to 200 cm2, for example.
Preferably, the water connections and, more preferably, the inlet and outlet of the electrochemical cell are formed from metal and grounded. This further increases the operational safety of the device.
Furthermore, the disclosure relates to a method for operating a water-conducting electrical device having a water receiving element, an electrochemical cell having electrodes and designed to produce a bleaching agent when it contains a salt-containing solution and a DC voltage is applied to the electrodes, a pump designed to convey fluid located in the electrochemical cell out of the electrochemical cell into the water receiving element, and a control unit, wherein the method has the following steps:
In step a), the metering unit preferably meters the salt-containing solution, and optionally washing agent, in a predetermined quantity into the electrochemical cell. The salt may be part of a washing agent.
In step b), the salt-containing solution fed in step b) by means of the is supplied with a DC voltage, e.g., between 1 and 50 V, which is applied to the electrodes, i.e., the anode and the cathode, so that a current-preferably of 1 to 20 A-flows. As a result, the chemical reaction or electrolysis takes place, and the bleaching agent, e.g., H2O2, is produced.
Step c) is preferably performed as soon as the chemical reaction has taken place, i.e., step b) has ended. Step c) serves to heat the fluid located in the electrochemical cell in the electrochemical cell. As a result, the cleaning effect of the bleaching agent produced in step b) can be increased further. An AC mains voltage, e.g., 230 V AC, is preferably applied to the anode and cathode of the electrochemical cell. For this purpose, the relay preferably switches from the DC voltage—in particular, low DC voltage—to the mains voltage. In doing so, it is preferably evaluated how the mains plug is plugged in, and the rotary relay is used to ensure that the grounded N conductor is connected to the electrode that is arranged at the inlet and outlet of the electrochemical cell, such as the anode. It is thus ensured that only small leakage currents can flow through the water, in order to satisfy all safety requirements.
In step d), the fluid is conveyed out of the electrochemical cell into the water receiving element. As a result, a cleaning process of the water receiving element and/or objects located therein is performed. Steps c) and d) may be performed at the same time. Selectively, step c) is performed before step d).
Preferably, water continues to be fed to the electrochemical cell. This step serves in particular to add a water quantity required for the cleaning process and/or to dilute the bleaching agent concentrate produced in the electrochemical cell. If the device is a washing machine, the required water quantity depends, for example, upon an amount of laundry, i.e., its loading ascertained by the device. By mixing the concentrate located in the electrochemical cell with the water, the conductivity of the solution decreases, so that a required heating power is produced when the AC voltage from the mains is applied to the anode and the cathode of the electrochemical cell. The heating power required can, for example, be approximately 1 to 3 KW, depending upon the type of device and power supply. In application concentration, the salt-containing solution, which is fed according to the cell size of the electrochemical cell in step a), ensures the required conductivity. The application concentration is higher than the maximum conductivity of drinking water, so that the individual properties of the water used do not play a role.
For example, the electrochemical cell can be filled with water before and/or during step a). If the device has a recirculation system, the water is preferably fed to the electrochemical cell via the recirculation system. For example, by opening the valve, water is fed from the water connection via the feed line to the water receiving element, and, via activation of the recirculation pump, the water is conveyed in the predetermined water quantity into the electrochemical cell. The inlet and outlet of the electrochemical cell are preferably arranged in the upper part of the electrochemical cell, so that a defined quantity of water remains in the electrochemical cell after the recirculation pump has been switched off.
Preferably, in step c), the water is preferably circulated by means of the pump so that it flows through the electrochemical cell and the water receiving element. As a result of the flow, the water is swirled in the electrochemical cell, and the bleaching agent and, optionally, washing agent are mixed with the water.
An exemplary embodiment of the disclosure is shown purely schematically in the drawings and is described in more detail below. Shown schematically and not to scale are:
Furthermore, the device has a recirculation system 4 for conducting water from a first region of the water receiving element 1 into a second region of the water receiving element 1. The recirculation system 4 has a recirculation pump 9 designed to pump water out of the first region through the electrochemical cell 3 into the second region. Furthermore, water can be pumped out of the first region through an outlet pump 5 of the device into an outlet line 6 connected to a wastewater channel (not shown) in order to remove or discharge the water from the washing machine. The recirculation pump 9 is connected via a line 7 to the lower region of the water receiving element 1. An inlet and an outlet of the electrochemical cell 3 are arranged in an upper part of the electrochemical cell 3, wherein the inlet is connected to the recirculation pump 9, and the outlet is connected to a line 11 designed to feed water, conducted through it, to the second region of the water receiving element 1.
The electrochemical cell 3 is connected via an outlet valve 10 to a point of the recirculation system 4 that is fluidically arranged upstream of the outlet pump 5. Furthermore, the device has a metering unit 12 designed to meter a salt-containing solution, and, optionally, a washing agent, by means of a metering pump 13 into the electrochemical cell 3. Furthermore, the device has a control unit 18 configured to selectively apply both DC and AC voltage to the electrochemical cell 3. The device is connected to a water connection 16 via an inlet line 14 and a valve 15. The control unit 18 is configured to automatically control a water supply from the water connection 16 into the water receiving element 1.
The outlet valve 10 is arranged between the line 7 and the electrochemical cell 3. This outlet valve 10 makes it possible to flush the electrochemical cell 3. For flushing the electrochemical cell 3, the outlet valve 10 is opened, and the outflowing water is discharged by means of the outlet pump 5.
During operation, a method for washing laundry has the following steps:
Water is fed from the water connection 16 via the valve 15 and the feed line 14 into the water receiving device 1 and pumped via the recirculation pump 9 into the electrochemical cell 3 so that water is fed in a predetermined quantity to the electrochemical cell 3. Subsequently or simultaneously, a salt-containing solution and, where applicable, a washing agent is metered out of the metering unit 12 via the metering pump into the electrochemical cell 3. Following the preceding steps, a DC voltage is applied to the anode A and the cathode K of the electrochemical cell 3 for a predetermined period of time. As a result, the chemical reaction takes place in the form of electrolysis, and the bleaching agent, such H2O2, is produced. Thereafter, water is fed in a further predetermined water quantity from the water connection 16 via the valve 15 and the feed line 14 into the water receiving element 1. Subsequently, the recirculation system 4 is activated so that the water is conducted out of the first region into the second region, passing through the electrochemical cell 3, wherein an alternating voltage is applied to the electrochemical cell 3 in order to heat the fluid passing through the electrochemical cell 3. By mixing the salt-containing solution and, where applicable, washing agent in the form of a concentrate with the water, the conductivity of the solution decreases, so that the required heating power is produced when the AC voltage is applied to the electrodes. For this purpose, a relay (not shown) of the control unit 18 switches from the DC voltage to the mains AC voltage.
During operation, control and monitoring take place by means of the control electronics. The mains voltage is fed to the control electronics. The latter serves to supply voltage. Furthermore, the control unit 18 has a protective ground 21, so that the control electronics can determine the polarity of the supply voltage. The rotary relay 19 is controlled such that the line with a low voltage against ground (N potential) is always connected to the anode A of the electrochemical cell 3. In order to produce the bleaching agent, a DC voltage—in particular, a low DC voltage—is produced from the mains voltage by means of the relay 20 and is applied by the control electronics to the electrodes, i.e., anode A and cathode K. For heating, the rotary relay 19 is first appropriately controlled, and the relay 20 is then used to switch on heating by applying an alternating voltage to the anode A and the cathode K. In this case, the anode potential is fed back to the control electronics. If a critical voltage against the ground potential of the protective conductor 23 occurs at the anode A, the control electronics switches off the heater.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020/5915 | Dec 2020 | BE | national |
The present disclosure claims priority to and the benefit of PCT Application PCT/EP2021/083500, filed on Nov. 30, 2021, which claims priority to and the benefit of Belgium Application 2020/5915, filed on Dec. 14, 2020, the entire contents of both of which are incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/083500 | 11/30/2021 | WO |
