WATER-CONDUCTING ELECTRIC DEVICE AND METHOD FOR OPERATING A WATER-CONDUCTING ELECTRIC DEVICE

Abstract

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 configured to selectively apply both DC voltage and AC voltage to the electrodes of the electrochemical cell. A method for operating the water-conducting electrical device includes feeding a salt-containing solution into the electrochemical cell, applying DC voltage to the electrodes of the electrochemical cell for a predetermined period of time in order to produce the bleaching agent in the electrochemical cell, applying AC voltage to the electrodes of the electrochemical cell for a predetermined period of time in order to heat fluid located in the electrochemical cell, and conveying the fluid out of the electrochemical cell into the water receiving element.

Claims

1. A water-conducting electrical device comprising: a water receiving element, an electrochemical cell having electrodes and configured to produce a bleaching agent when it contains a salt-containing solution and a DC voltage is applied to the electrodes, a pump configured to convey fluid located in the electrochemical cell out of the electrochemical cell into the water receiving element, and a control unit configured to selectively apply both DC and AC voltage to the electrodes of the electrochemical cell.

2. The device according to claim 1, wherein the control unit has a relay designed to switch from DC to AC voltage and vice versa.

3. The device according to claim 1, wherein the control unit 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, and/or the control unit has a protective ground designed such that a polarity of the supply voltage can be determined.

4. The device according to claim 1, further comprising 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.

5. The device according to claim 1, wherein an inlet and an outlet of the electrochemical cell are arranged in an upper part of the electrochemical cell, in relation to an operational set-up position of the device, wherein the inlet is connected to the pump and the outlet is connected to a line designed to feed fluid through the line to the water receiving element.

6. The device according to claim 1, wherein the electrochemical cell is connected via an outlet valve to a point of a water line system of the device that is arranged fluidically upstream of an outlet pump designed to discharge water from the device.

7. The device according to claim 1, wherein it can 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.

8. The device according to claim 1, further comprising a metering unit designed to meter the salt-containing solution into the electrochemical cell.

9. 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: a) feeding a salt-containing solution into the electrochemical cell; b) following step a), applying DC voltage to the electrodes of the electrochemical cell for a predetermined period of time in order to produce the bleaching agent in the electrochemical cell; c) following step b), applying AC voltage to the electrodes of the electrochemical cell for a predetermined period of time in order to heat fluid located in the electrochemical cell; and d) conveying the fluid out of the electrochemical cell into the water receiving element.

10. The method according to claim 9, wherein water continues to be introduced in a predetermined water quantity into the electrochemical cell.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] 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:

[0041] FIG. 1 a sketch-like sectional illustration of the water-conducting electrical device according to the disclosure; and

[0042] FIG. 2 a circuit diagram of a control unit of the device shown in FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS

[0043] FIG. 1 shows a sketch-like sectional illustration of a water-conducting electrical device according to the disclosure. The device shown in FIG. 1 is a washing machine having a water receiving element 1 designed as a suds container and designed to receive water. A drum 2 for receiving laundry 8 is rotatably mounted in the water receiving element 1. The device further has an electrochemical cell 3 having electrodes in the form of an anode A and a cathode K and designed to produce a bleaching agent when it contains a salt-containing solution and a DC voltage is applied to the anode A and the cathode K.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] During operation, a method for washing laundry has the following steps:

[0048] 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.

[0049] FIG. 2 shows a circuit diagram of a control unit of the device shown in FIG. 1. The control unit 18 has a mains connection 24 designed to provide AC voltage, a relay 20 designed to convert DC voltage into AC voltage and vice versa, and a DC-out socket 22. A control electronics (not shown) of the control unit 18 is designed to evaluate how a mains plug (not shown) is plugged in and ensures, by means of a rotary relay 19 of the control unit 18, that a grounded N conductor 23 is always connected to the electrode that is arranged at the inlet and outlet of the electrochemical cell 3. When viewing FIGS. 1 and 2 together, this electrode is the anode A.

[0050] 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 voltagein particular, a low DC voltageis 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.

LIST OF REFERENCE SIGNS

[0051] A Anode [0052] AC Mains voltage [0053] K Cathode [0054] 1 Water receiving element [0055] 2 Drum [0056] 3 Electrochemical cell [0057] 4 Recirculation system [0058] 5 Outlet pump [0059] 6 Outlet pipe [0060] 7 Line [0061] 8 Laundry [0062] 9 Recirculation pump [0063] 10 Outlet valve [0064] 11 Line [0065] 12 Metering unit [0066] 13 Metering pump [0067] 14 Feed line [0068] 15 Valve [0069] 16 Water connection [0070] 18 Control unit [0071] 19 Rotary relay [0072] 20 Relay [0073] 21 Protective ground [0074] 22 DC-out socket [0075] 23 Grounded N conductor [0076] 24 Mains voltage connection