EP2462272B1 - Water-bearing household appliance having a filter device in the pumping-away section and storage tank - Google Patents

Description

The invention relates to a water-conducting domestic appliance, in particular a laundry treatment appliance for washing and / or drying laundry. Specifically, the invention relates to the field of washing machines and washer-dryers.

From the U.S. Patent 5,868,937 For example, a method and apparatus for treating and reusing wastewater is known. In the device thus known a circulation pump is provided, which promotes via a filter element with high capacity wastewater in an intermediate container. From the intermediate container, the waste water can be pumped back or pumped back into a laundry drum or the like. Furthermore, an additional filter device is provided, from which water can be filtered from the intermediate container. The device is independent of a domestic appliance, but can be used to treat waste water from a domestic appliance. The from the U.S. Patent 5,868,937 known device and the method known from it have the disadvantage that the cost of filtering is relatively large. In addition, there is a certain maintenance, since the filter elements must be replaced after a certain time.

The DE 197 09 085 A1 discloses a method for washing laundry in which the washing water is collected in an intermediate container, filtered and collected in a storage. Since a cross-flow filter is used as the filter, several cycles are required. In addition, the filter device is arranged parallel to the pumping line, which requires two storage containers. Such a construction is technically complex and requires a lot of space, which generally lacks in a washing machine.

From the DE 29 10 140 a device for automatically washing and rinsing laundry with a collection container is known. Rinsing liquors are stored in this collecting tank until the next washing process is carried out.

From the EP 0 207 379 A1 is a hollow fiber filter known. From the DE 101 61 095 C1 a method for membrane filtration is known

An object of the invention is to provide a water-conducting household appliance, in which a possible water storage is improved.

The object is achieved by a water-conducting domestic appliance according to the invention, in particular a laundry treatment appliance for washing and / or drying laundry, in which a treatment area, a pumping line connected to the treatment area, a drain pump arranged in the pumping line, a water reservoir and a filter device are provided, wherein stored in the water storage water is feasible in the treatment area, wherein the filter device between the treatment area and the drain pump is arranged in the Abpumpstrang, wherein the filter means is connected to the water reservoir to divert water from the arranged in the Abpumpstrang filter device in the water reservoir, wherein the filter device comprises a filter which filters the wastewater diverted into the water reservoir and wherein the water reservoir is connected to the filter device via a bidirectional pump.

The measures listed in the dependent claims advantageous refinements of the water-conducting household appliance according to the invention are possible.

The filter device is arranged between the treatment area and the drain pump in the pumping line. In this case, it is also advantageous that the filter device is arranged on a suction side of the drain pump. As a result, an advantageous mode of operation of the water-conducting domestic appliance for storing filtered water in the water storage is made possible.

Advantageously, the water reservoir is used to store a certain amount of water, which is branched off from the arranged in the Abpumpstrang filter device into the water reservoir. In this case, the water is filtered in an advantageous manner by the filter device, so that filtered water can be obtained from the wastewater discharged via the pumping line. In this case, the filter device can filter the water more or less. The extent of filtering depends on the expected contamination of the wastewater used for filtering and the intended use for the stored water. For example, the water-bearing domestic appliance can be configured such that the water branched off into the water reservoir is diverted during a wash cycle, preferably the last wash cycle. The pollution of the waste water of the last wash cycle is in the Usually relatively low. Furthermore, the stored water can be used for a Vorrvaschgang, which is followed by a main wash cycle. Furthermore, the requirements for the filter device also depend on the expected service life of the water in the water reservoir. Specifically, the filter device can also be used for filtering bacteria and the like. Thus, the filter device can be adapted to the particular application.

It is advantageous that the filter device has a filter chamber and a filter arranged in the filter chamber, that the filter filters the waste water diverted into the water reservoir, wherein residues accumulate in the filter, and that passed through the Abpumpstrang to an outlet wastewater through the filter device is guided, that a entrainment of residues collected in the filter is made possible by the wastewater. The water branched off into the water reservoir can thereby be guided in an advantageous manner through the filter of the filter device. As a result, depending on the design of the filter, the desired purity of the water stored in the water reservoir can be achieved. However, there is the problem that the filter becomes clogged with residues over time. However, these residues are taken along by the wastewater, which is passed through the pumping line to the outlet. The waste water passes through the filter chamber, whereby it flows past the filter, that a cleaning effect is achieved with respect to the filter. As a result, depending on the configuration of the filter device, a maintenance-free design of the filter device or at least a longer service life of the filter can be achieved. As a result, a user-friendly design of the water-bearing household appliance is possible, whereby the water consumption can be reduced by the stored water.

It is also advantageous here that the filter is configured as a hollow-fiber membrane filter, that the filter device has a flange, that the water reservoir is at least indirectly connected to the flange and that the two ends of the hollow fibers of the hollow fiber membrane filter are connected to the flange. In hollow-fiber membrane filters in which the liquid to be purified is forced into the fiber interior through pores in the fiber sheath and transported away like in a hose, a high surface in relation to the required volume can be used for filtering. In this case, for example, a bundle with 100 to 1000 fibers bent in a U-shape and the front side can be taken in the flange. The wastewater to be filtered is led into the filter room and driven by a pressure difference between the filter chamber and the flange through the pores in the fiber cladding. The thereby deposited substances form residues that accumulate on the outside of the surface of the shell of the individual hollow fibers, while the purified water is passed through the cavity of the hollow fibers via the flange to the water reservoir. Due to the very large surface area of the hollow-fiber membrane filter, even at a relatively low pressure, for example at a pressure difference of 50 kPa (0.5 bar), filtration and thus filling of the water reservoir can take place. The required pressure difference also depends on the desired cleaning effect. By self-cleaning of the filter device, which takes place when flowing through the filter chamber with the wastewater to the output, an increase in the pressure required for filtering is avoided. Since the feed system of the filter device can thus remain pressure-free, in contrast to pressurized systems during filter operation, no special measures for foreclosure from the rest of the system are required. In addition, this also results in the possibility of parallel operation of pumping and filtering.

Advantageously, the hollow-fiber membrane filter comprises a multiplicity of hollow fibers which are arranged in the filter chamber such that the stream of wastewater guided through the pumping-down strand to the outlet mechanically moves the hollow fibers towards one another. In this case, it is also advantageous that the hollow fibers of the hollow-fiber membrane filter are arranged in the filter chamber such that they rub against one another during the mechanical movement caused by the flow of the wastewater. Thus, when pumping the waste water to the outlet of the water-bearing household appliance by the drain pump automatic cross-scouring be generated, which achieves a good cleaning effect in the hollow fiber membranes by their easy mobility. Because of the quantities of water to be pumped off and their mechanical energy during pumping, the cleaning of the filter device can be realized without further effort. In particular, neither additional technical measures nor an additional energy input are required. The filter device is low-maintenance or even maintenance-free thanks to the automatic transverse flushing. Additional special filter cleaning programs with additional hardware, time and energy overhead are thus not necessarily required.

The water reservoir is connected via a pump to the filter device. In this case, the pump can advantageously as a against the Be configured ambient pressure working suction pump, since the pressure to be applied when using a hollow fiber membrane filter is relatively low.

It is also advantageous that a controller is provided and that the controller for draining water from the arranged in the Abpumpstrang filter device in the water storage shuts off the drain pump and the pump, via which the water storage is connected to the filter device, turns on. As a result, for example, be filled during a last rinse the water tank. The pump, via which the water reservoir is connected to the filter device, is designed as a bidirectional pump. It is advantageous that the control switches off the drain pump in a filter cleaning mode and activates the pump, via which the water reservoir is connected to the filter device, in the opposite direction in order to assist filter cleaning of the filter of the filter device by backwashing water from the water reservoir into the filter chamber of the filter device. Thus, by the bidirectional suction pump in the printing operation, the cleaning effect by backwashing during pumping can be further supported. Such a cleaning program can thus be integrated into a normal washing process. The filter cleaning can be carried out, for example, after a certain number of program runs. The system of water storage, filter device and pumps is designed to be compact and robust and can be accommodated, for example, additionally in the bottom area of a designed as a front load water-bearing household appliance together with other, optionally required auxiliary components.

The inventive water-bearing domestic appliance and its advantageous developments also define advantageous process steps for controlling the water-bearing household appliance.

Fig. 1

ein wasserführendes Hausgerät in einer schematischen Darstellung entsprechend einem Ausführungsbeispiel der Erfindung.

Preferred embodiments of the invention are explained in more detail in the following description with reference to the accompanying drawings. It shows:

Fig. 1

a water-conducting household appliance in a schematic representation according to an embodiment of the invention.

Fig. 1 shows functional components and assemblies of a water-bearing household appliance 1 in a schematic representation. The water-bearing domestic appliance 1 can in particular be configured as a laundry treatment appliance and serve for washing and / or drying laundry. Specifically, the water-bearing domestic appliance 1 can be configured as a washing machine or washer-dryer. However, the features of the water-conducting household appliance 1 specifically explained here are also suitable for other applications, in particular, the domestic appliance can be designed as a dishwasher.

The water-bearing domestic appliance 1 has a container 2, which is designed in this embodiment as a tub. The container 2 encloses a treatment area 3 of the water-conducting household appliance 1.

The water-bearing domestic appliance 1 has a connection 4, on which the water-bearing domestic appliance 1 can be connected to a fresh water line. From the connection 4, a line 5, in which a check valve 6 is arranged, leads to an induction bowl 7. In the induction bowl 7, a treatment agent, in particular a laundry treatment agent, can be provided. When supplying fresh water via line 5, the fresh water passes through a free air gap in the dispenser 7 and rinses the laundry treatment agent, in particular a detergent or a softener, from the dispenser 7 via a connecting channel 8 in the container 2. With the mixture of water and Laundry treatment, the laundry provided in the container 2 can be treated. As a result, a washing or other treatment of the laundry is possible. After a washing or another treatment process, the wastewater can be pumped out of the treatment area 3 via a pumping line 9 by means of a drain pump 10 arranged in the pumping line 9. In this case, a connection 11 is provided, with which the pumping line 9 of the water-conducting household appliance 1 can be connected to a sewage pipe.

During a program run 5 fresh water can be fed several times via the line. For example, one or more rinses may be provided to rinse the laundry provided in the treatment area 3. At least part of the rinsing water can be temporarily stored in a water storage 12 of the water-bearing household appliance 1. The water reservoir 12 is connected via a line 13 to the connecting channel 8. In line 13, a pump 14 is arranged. The water stored in the water storage 12 may replace a part of the supplied fresh water in another application. This can save water.

For example, in another application during a prewash, a portion of the supplied via the line 5 fresh water can be replaced by the water stored in the water tank 12. The water storage 12 may for example have a storage volume of 12 liters.

In the Abpumpstrang 9 a filter device 20 is arranged. The filter device 20 has a filter chamber 21 and a filter 22 arranged in the filter chamber 21. Here, the filter device 20 between the container 2, which surrounds the treatment area 3, and the drain pump 10 is arranged in the Abpumpstrang 9. Specifically, the filter device 20 may be arranged on a suction side 23 of the drain pump 10.

The wastewater guided via the pumping line 9 through the drain pump 10 to the connection 11 flows through the filter space 21 of the filter device 20. During a wash cycle, relatively clean wastewater is located in the filter space 21.

The water-bearing domestic appliance 1 of this embodiment has a controller 24. In addition, a pump 25 is provided, via which the filter device 20 is connected to the water reservoir 12. Here, the pump 25 is arranged in a line 26 which is connected on the one hand with a flange 27 of the filter device 20 and on the other hand with the water reservoir 12.

The controller 24 is connected via a control line 28 to the drain pump 10, via a control line 29 to the pump 25 and via a control line 30 to the pump 14. To drain the residual water from the container 2 to the port 11, the controller 24 operates the drain pump 10. To store a certain amount of water in the water tank 12, the controller 24 switches off the drain pump 10 and actuates the pump 25. This is preferably done after a rinse. Here is located in the filter chamber 21 relatively clean water, which is filtered when operating the pump 25 via the filter 22. The filtered water through the filter 22 can be cached in the water storage 12 for later use. When the water reservoir 12 is filled, then the controller 24 shuts off the pump 25. The remaining residual water can then be completely pumped out of the container 2 by actuating the drain pump 10. To direct water from the water reservoir 12 to replace a portion of the fresh water in the container 2, the controller 24 operates the pump 14th

The filter 22 of the filter device 20 is designed as a hollow fiber membrane filter. In this case, the filter 22 a plurality of hollow fibers 31, wherein in the Fig. 1 For simplicity of illustration only the hollow fiber 31 is indicated. In this case, for example, about 100 to 1000 such hollow fibers 31 may be provided. Each of the hollow fibers 31 is bent in a U-shape, wherein both an end 32 of the hollow fiber 31 and an end 33 of the hollow fiber 31 are gripped in the end face of the flange 27. Over the lateral surface of the hollow fiber 31, the water passes from the filter chamber 21 into the interior of the hollow fiber 31. From the interior of the hollow fiber 31, the filtered water is conveyed through the pump 25 into the water reservoir 12. Due to the large number of hollow fibers 31, a very large surface area of the filter 22 is created in relation to the required volume. As a result, a relatively low delivery pressure of the pump 25 is sufficient. Specifically, the pump 25 may be designed as a suction pump, which applies a pressure of about 50 kPa (0.5 bar) against the ambient pressure.

During the filtering of the water fed into the water reservoir 12, residues of the wastewater remain on the surface (lateral surface) of the hollow fibers 31 of the filter 22. However, the design and arrangement of the filter device 20 enables a cleaning of the filter 22 and thus prevents a progressive clogging of the filter 22.

Due to the inherent elasticity of the hollow fibers 31 and thus their mobility, a cleaning of the filter 22, which consists of the plurality of hollow fibers 31, be realized by relatively low mechanical energy input. Due to the arrangement of the filter device 20 in the pumping line 9, in particular at the given by the suction side 23 inlet of the drain pump 10, the pumped out of the container 2 via the drain pump 10 to the port 11 wastewater flows around the outside (surface) of Hohtfasern 31. Thus Residues that have accumulated on the outside of the hollow fibers 31, while washing off the waste water constantly washed off. The washing of the hollow fibers 31 of the filter 22 takes place on the one hand by the mechanical movement of the stream of wastewater (wastewater stream). The wastewater enriched with the residues of the filter 22 reaches the connection 11 from the water-conducting domestic appliance 1. On the other hand, the individual hollow fibers 31 are arranged in the filter space 21 so that they rub against each other. Through this mechanical friction, a further cleaning effect is generated, which is used to remove the when filtering left behind residues on the outside of the hollow fibers 31 leads.

In an advantageous manner, the filling of the water reservoir 12 takes place relatively late within a washing program, for example during the last rinse cycle. At the next program run, in which dirty laundry is again in the container 2, the filter chamber 21 to the port 11 through-flowing wastewater is gradually cleaner. This corresponds to the normal course of the washing program, which may consist of pre-washing, main washing and one or more rinses. During this flushing of the filter chamber 21 and the filter 22 is flushed through and thus cleaned. As the wastewater becomes cleaner, the degree of purification of the filter 22 also gradually improves. Thus, the filter 22 is at least largely cleaned during the last rinse. By means of the cleaned filter 22, at least part of the wastewater from the last rinse cycle can thereby be filtered in order to fill the water reservoir 12. The standing in the filter chamber 21 wastewater is here deducted from the pump 25 on the flange 27 of the hollow fiber membrane filter 22.

The configuration of the hollow fibers 31 of the filter 22 is predetermined with respect to the respective application. Specifically, a pore width of the hollow fiber membranes may be selected from a relatively wide range. Specifically, hollow fibers 31 having pores having a pore width of about 6 nm may be selected. By such a pore size and bacteria or the like can be filtered off. The filter chamber 21 may be configured as a filter chamber. The filter chamber 21 may in this case also be formed by a chamber on the suction side 23 of the drain pump 10, which is formed within the housing of the drain pump 10.

The water-bearing domestic appliance 1 may also include a filter cleaning mode. Here, the pump 25 is designed as a bidirectional pump 25 so that it can pump water from the water reservoir 12 in the filter chamber 21 of the filter device 20 in the opposite direction. In the filter cleaning mode, the controller 24 controls the pump 25 in the opposite direction, while the drain pump 10 for pumping waste water through the Abpumpstrang 9 to the port (output) 11 runs. The cleaning of the filter 22 from the residues is in this case supported by the backwashing of water from the water reservoir 12 into the filter chamber 21. Thus, in the filter cleaning mode, improved cleaning of the hollow fibers 31 of the filter 22 can occur. Here, there is the advantage that the cleaning mode during a Program run when pumping can be performed. A user intervention or special selection by the user is not required. The cleaning mode may be automatically executed by the controller 24 after a certain period of operation or after a certain number of program runs.

Depending on the design of the water-conducting domestic appliance 1, other modes are possible. For example, the controller 24 may operate the pump 25 to fill the water reservoir 12 even during the pump down, in which the drain pump 10 is running.

The invention is not limited to the described embodiments.

LIST OF REFERENCE NUMBERS

1

Water-conducting household appliance

2

container

3

treatment area

4

connection

5

management

6

check valve

7

dispenser tray

8th

connecting channel

9

Abpumpstrang

10

Drain pump

11

connection

12

water-tank

13

management

14

pump

20

filter device

21

filter chamber

22

filter

23

suction

24

control

25

pump

26

management

27

flange

28, 29, 30

control line

31

hollow fiber

32, 33

Ends of the hollow fiber 31

Claims (8)

1. Water-conducting domestic appliance (1), particularly laundry treatment appliance for washing and/or drying laundry, with a treatment region (3), a pumping-out train (9) connected with the treatment region (3) and a solution pump (10) arranged in the pumping-out train (9), wherein a water reservoir (12) and a filter device (20) are provided and wherein water stored in the water reservoir (12) can be conducted into the treatment region (3), wherein the filter device (20) is arranged between the treatment region (3) and the solution pump (10) in the pumping-out train (9), wherein the filter device (20) is connected with the water reservoir (12) in order to branch off water from the filter device (20), which is arranged in the pumping-out train (9), into the water reservoir (12) and wherein the filter device (20) comprises a filter (22) which filters waste water branched off into the water reservoir (12), characterised in that the water reservoir (12) is connected with the filter device (20) by way of a bidirectional pump (25).
2. Water-conducting domestic appliance according to claim 1, characterised in that the filter device (20) has a filter chamber (21) and the filter (22) arranged in the filter chamber (21), that the filter (22) filters the waste water branched off into the water reservoir (12), wherein residues collect in the filter (22), and that the waste water led by the pumping-out train (9) to a connection (11) is so conducted through the filter device (20) that entrainment of residues, which have collected in the filter (22), by the waste water is made possible.
3. Water-conducting domestic appliance according to claim 2, characterised in that the filter (22) is constructed as a hollow-fibre membrane filter and the filter device (20) has a flange (27), that the water reservoir (12) is connected at least indirectly with the flange (27) and that the two ends (32, 33) of the hollow fibres (31) of the hollow-fibre membrane filter (22) are connected with the flange (27).
4. Water-conducting domestic appliance according to claim 3, characterised in that the hollow-fibre membrane filter (22) comprises a plurality of hollow fibres (31) which are so arranged in the filter chamber (21) that the flow, which is led by the pumping-out train (9) to the connection (11), of the waste water mechanically moves the hollow fibres (31) relative to one another.
5. Water-conducting domestic appliance according to claim 4, characterised in that the hollow fibres (31) of the hollow-fibre membrane filter (22) are so arranged in the filter chamber (21) that these rub against one another when the mechanical movement caused by the flow of the waste water takes place.
6. Water-conducting domestic appliance according to claims 1 to 5, characterised in that a control (24) is provided and that the control (24) for branching-off water from the filter device (20), which is arranged in the pumping-out train (9), into the water reservoir (12) switches off the solution pump (10) and switches on the pump (25) by way of which the water reservoir (12) is connected with the filter device (20).
7. Water-conducting domestic appliance according to claim 6, characterised in that the control (24) in a filter cleaning operating mode switches off the solution pump (10) and activates the pump (25), by way of which the water reservoir (12) is connected with the filter device (20), in opposite direction in order to assist filter cleaning of a filter (22) of the filter device (20) by back-flushing of water from the water reservoir (12) into a filter chamber (21) of the filter device (20).
8. Water-conducting domestic appliance according to any one of the preceding claims, characterised in that the filter device (20) is arranged at a suction side (23) of the solution pump (10).

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