WO2013068300A1

WO2013068300A1 - Washing machine with filtration device and method for the operation thereof

Info

Publication number: WO2013068300A1
Application number: PCT/EP2012/071684
Authority: WO
Inventors: Antonio BARRADO FRANCO; Andreas Bischof; Andreas Hanau; Hartmut Schaub
Original assignee: BSH Bosch und Siemens Hausgeräte GmbH
Priority date: 2011-11-11
Filing date: 2012-11-02
Publication date: 2013-05-16
Also published as: DE102011086137B4; IN2014KN00880A; CN103917710B; DE102011086137A1; CN103917710A; RU2014122850A; RU2586044C2; EP2776618A1

Abstract

The invention relates to a washing machine with a suds container (1), a washing drum (2), a water inlet system (8, 9), a suds pump (16), a program controller (12) and at least one filtration device (17, 29, 30), wherein the at least one filtration device (17, 29, 30) is arranged between the suds container (1) and a supply line (10) to the suds container (1) and the washing machine is designed in such a manner that an aqueous fluid (6) present in the suds container (1) can be filtered at least part of the time during a laundry treatment step by being conducted through the at least one filtration device (17, 29, 30) and fed back to the suds container (1), and at least two filtration devices (17, 29, 30) with different average pore widths are present. The invention also relates to a method for treating laundry in said type of washing machine.

Description

Washing machine with filtration device and method of operation

The invention relates to a washing machine with a filtration device and a method for their operation. In particular, the invention relates to a washing machine with a tub, a laundry drum, a water supply system, a drain pump, a program control and at least one filtration device and a method for treating laundry in such a washing machine.

The currently common laundry treatment processes in a washing machine consist of several treatment steps (wetting phase, pre-wash, main wash, rinse), which are each associated with a more or less complete replacement of the aqueous liquid in the tub. Each laundry treatment step generally begins with the supply of fresh water, which is disposed of as wastewater at the end of each treatment step. In order to minimize the carry-over of treatment agent residues (for example detergents, softeners) into further treatment steps by residues of an aqueous liquid used in the tub, so-called spin-drying cycles are switched, in which the drum is rotated at a high number of revolutions.

For the operation of a washing machine, the water consumption is an important operating size. For economic and ecological reasons, it is desirable to keep the water consumption as low as possible, whereby due to the mechanical engineering conditions and the suction behavior of the laundry to be treated a minimum consumption of water is predetermined.

When treating soiled laundry in a washing machine, generally following the actual washing step, using suitable cleaning agents, is followed by a rinsing phase with one or more rinsing steps with water. In this rinsing phase, the items of laundry are freed from the wash liquor enriched with impurities and cleaning agents and, if appropriate, residues of impurities and cleaning agents still adhering to the laundry items. The remaining on the fibers of the laundry after the rinsing phase traces of such substances are all the more less than more water used during rinsing and / or more frequent rinsing with water. However, the time and amount of water used for rinsing should be reduced due to the demands of users of washing machines and in view of a generally desirable economical use of water while maintaining a high rinsing efficiency.

DE 10 2009 055 276 A1 describes a washing machine with a lye container, a laundry drum, a water supply system and a lye drain system with a drain pump, a program control, a desalting device for producing demineralized water and a rinse water storage, wherein the washing machine has a soft water tank, via the Desalting device is connected to the water supply system. The desalting device is in particular a reverse osmosis device, a nanofiltration device, an electrodialysis device and / or an ion exchanger.

DE 19 44 397 A describes a washing machine or dishwasher with a device for water softening, which works on the principle of reverse osmosis, with at least one semipermeable film, which is associated with its one surface of a water supply line and with its other surface of a water drain line. In the drawing, a dishwasher is shown, in which a reservoir for softened water can be provided, which is equipped with a drain valve.

DE 197 09 085 A describes a method for washing laundry, in particular in a domestic washing machine, in which the laundry is treated in a suds container during a washing section with washing liquid and during subsequent rinsing sections with rinsing liquid. At the end of the respective washing / rinsing section, the tub is emptied, with washing liquid and / or rinsing liquid of at least one rinsing section being emptied into a collecting container and, after conditioning by a reverse osmosis, micro, ultra or nanofiltration process, with intermediate storage in a storage container be reused. The treated washing or rinsing liquid is fed to a later rinsing section of the same program sequence. DE 38 05 565 A1 describes a method and a device for cleaning soiled parts by means of a washing or rinsing agent containing washing or rinsing liquor at elevated temperature, in which after washing or rinsing the washing or rinsing liquor passed through a filter which removes fat and / or dirt from the washing or rinsing liquor, and the thus-filtered washing or rinsing liquor with the washing or rinsing agent contained therein is then stored for use in a further washing or rinsing process.

EP 0 578 006 A1 describes a method for washing clothes or dishes, comprising at least one washing phase and a plurality of subsequent rinsing phases, these phases being preceded by water filling phases, in which the liquid is introduced into a suitable container containing the objects to be treated , Then there are phases in which the liquid used for a single treatment is led out of the container. The liquid used for the rinsing phases is subjected to a preceding cleaning phase, which consists of at least one treatment by reverse osmosis or ultrafiltration or nanofiltration or a combination thereof.

EP 0 467 028 A1 describes a process for treating laundry or dishes comprising a preliminary water purification phase, at least one water filling phase in which this water is introduced into a receiving container, at least one washing phase and at least one rinsing phase, wherein the water purification phase is carried out by the water for the washing phase is supplied to at least one of reverse osmosis or ultrafiltration or a combination of both.

EP 0 845 555 A1 describes a method and a system for washing textiles in which one or more washing and rinsing cycles are carried out in one step and the water from this step is fed into a reverse osmosis unit in order to remove impurities from the water , Then the water is recycled into the washing machine.

WO 02/057531 A1 describes a system and a method for an economically and environmentally feasible central treatment of laundry, in which the Washing or rinsing water is then filtered with at least one filter.

Post-published EP 2 455 533 A1 describes a method for operating a washing machine and a washing machine, wherein the washing machine can be operated in a so-called recirculation washing mode in which a filter clogging state of a filter for the washing liquid is tracked. In the method, upon detection of a critical filter clogging condition, the recirculation wash mode is deactivated and replaced by a noncirculating wash mode. During recirculation, the aqueous liquid is passed through a washing liquid filter 13. A draining filter element 8 is arranged so that the wash liquid is disposed of through this drain filter element.

Against this background, the object of the present invention was to provide a washing machine and a method for its operation with reduced water consumption. Preferably, this method should require less time to carry out a laundry treatment.

The object underlying the invention is achieved by a washing machine and a method for treating laundry in a washing machine according to the respective independent claim. Preferred embodiments of the invention are set forth in the respective dependent claims and the following description and attached drawing. Preferred embodiments of the washing machine correspond to preferred embodiments of the method and vice versa, although not separately pointed out here in each case.

The invention thus relates to a washing machine with a tub, a washing drum, a water supply system, a drain pump, a program control and at least one filtration device, wherein the at least one filtration device between the tub and a supply line to the tub is arranged and the washing machine is configured so that an aqueous liquid present in the tub can be at least temporarily filtered during a laundry treatment step by passing through the at least one filtration device and can be returned to the tub, whereby at least two filtrate Onsvorrichtungen different average pore size are available. This means in particular that the washing machine is designed so that an aqueous liquid present in the tub can be at least temporarily filtered during a laundry treatment step by passing through at least two filtration devices of different average pore size and fed back to the tub.

The water supply system may also be connected to the filtration device, so that, for example, a desalination of the tap water used can be made.

In a preferred embodiment, the washing machine is designed so that the aqueous liquid present in the tub is at least temporarily filtered during a laundry treatment step by passing through the at least one Filtrationsvor- direction and fed back to the tub. However, this does not exclude that the aqueous liquid is passed back into the tub in a lack of functionality of a filtration device, for example by clogging, by a filter bypass line to the filtration devices over. Alternatively, in case of a detected malfunction of one or more filtration devices used, the passage of the aqueous fluid through the at least one filtration device may be interrupted. In general, the passage of the aqueous liquid through the filtration device is carried out using a pump. For this purpose, for example, a pump generally used in a washing machine as part of a lye drainage system can be used. The interruption of the filtration can then be brought about, for example, by stopping the pump.

Advantageously, the washing machine therefore has a first sensor for determining the functionality of the filtration device. According to the invention, preference is given to a first sensor which is expediently arranged downstream of the filtration device, preferably between the filtration device and a storage tank, and measures the content of the water leaving the filtration device of impurities including dirt particles, laundry treatment agents and / or salts. The sensor may be, for example, a turbidity sensor known per se. However, it may also be provided, for example, a sensor for registering the presence of a filter in a filtration device or a filter membrane or a lonenaustauscherpatrone in the washing machine.

In particular, with a turbidity sensor insoluble particles, e.g. Dirt particles are detected qualitatively and quantitatively.

As the first sensor, a sensor for directly or indirectly detecting ions, e.g. an ion-selective electrode or a conductivity sensor. A conductivity sensor generally comprises two electrodes arranged in a liquid to be examined, which allow a statement about the qualitative and quantitative presence of various substances such as salts, detergents or fabric softeners via the conductivity measured between them.

The first sensor is preferably connected to the program control and can thus be used to monitor a functional capability, ie filtration capability, of the filtration device. In this case, the first sensor preferably measures a content of impurities l _imp in the water leaving the filtration device and compares the measured content l _imp with a predetermined upper limit value l _imp (max) stored, for example, in the program control. In this case, exhaustion of the filtration capability of the filtration device may preferably be indicated when l _imp (max) is reached or exceeded. If the filtration capability of the filtration device is running out, the turbidity value registered by a turbidity sensor or the conductance of the water emerging from the filtration device, which is the first sensor registered by a conductivity sensor, increases.

Via an optionally available display device of the washing machine can then be displayed the need for a filter replacement or a cleaning of the filtration device.

It is therefore preferred that the washing machine additionally has a display device for indicating the functionality of the at least one filtration device. If a malfunction is indicated, for example because a filtration Direction is no longer adequately filtered or even clogged, can be indicated by an audible and / or visual indication of a necessary cleaning or even a necessary replacement of a filtration device. For this purpose, for example, one or more buzzers with different sounds or tones, or a speech synthesizer with messages such as "change filter" or "clean filtration device" could be used as the acoustic display device, corresponding qualitative and quantitative information on the presence of contaminants such as dirt particles, fat or salts in the water or other inorganic and / or organic substances in the rinse water can also be given via an optical display device (LED or LCD).

According to the invention, it may be provided that a laundry treatment process is also carried out despite the lack of filtration capability. In addition, a second sensor may be provided, which is arranged in the tub of a washing machine and measures a content S of dissolved and / or undissolved inorganic and organic substances in the liquid present there and compares with a predetermined value S (min). The program control can then not only ensure that when reaching or falling below S (min), a water supply is stopped and / or no further rinsing step is carried out. In particular, it can also be arranged that further filtration of the aqueous liquid present in the tub is no longer necessary. If appropriate, aqueous liquid, which is in particular a rinsing liquid, can then be temporarily stored in a storage container for reuse.

The second sensor is preferably an optical sensor, a turbidity sensor, a Tensi ometer or a conductivity sensor. An optical sensor measures optical properties of a liquid that differ from water containing water and inorganic and / or organic substances. Accordingly, in an aqueous solution, a presence of inorganic and / or organic substances can be determined qualitatively and quantitatively. A tensiometer is generally a dynamic measuring system for determining the content of surface-active substances in a liquid. By means of the tensiometer, a signal proportional to the surface tension of the fluid is often produced by the bubble pressure method, which corresponds to the concentration surface-active substance corresponds. Particularly preferably, an optical sensor or a conductivity sensor is used as the second sensor. The second sensor is preferably located in the lower region of the tub. If a quantitative determination of the content of salt or inorganic and organic substances for the control of the at least one filtration device is desirable, stored in a memory of the program control, possibly stored data on the relationship between the type and concentration of salts or inorganic and organic substances and the Signal of the respective sensor (eg conductivity, surface tension, optical characteristics) are used.

It has been shown that by the filtration of the aqueous liquid in the tub a better and faster treatment, in particular cleaning, of laundry items can be effected. It is therefore generally advantageous if the washing machine is designed to guide the aqueous liquid through the at least one filtration device during the entire duration of at least one laundry treatment step.

In a particularly preferred embodiment, the washing machine according to the invention is designed so that the aqueous liquid in the tub is passed through the at least one filtration device during the entire duration of all laundry treatment steps of a washing program.

Preferably, the washing machine comprises a first storage container for filtered aqueous liquid, i. Water, which is generally downstream of the filtration device and e.g. can be referred to as a soft water tank.

For additional water savings, the used rinse water can be reused. As an alternative or in addition to the first storage container, the washing machine according to the invention therefore preferably has a second storage container for an aqueous liquid from the tub, which can be referred to, for example, as a flushing water storage. In this, the used rinse water can be cached, and then used for example in a subsequent wash cycle. Due to the filtration provided in one embodiment of the invention of the rinse water, it is so clean that it can easily be used instead of fresh water for wetting and washing laundry. In addition, purified, and in particular desalted, used rinse water has the advantage that the detergent concentration does not have to be adjusted with respect to the degree of hardness, since the desalted water is already "soft" even if it has undergone a rinse cycle according to the invention Even more advantageously than fresh water.RTM .. The rinsing water filtered according to the invention is used in a washing cycle of a following washing process .Herein, the terms "first" and "second" storage containers mean only different names and do not imply that there are actually two storage containers in the presence of a second storage container In addition, first and second storage containers may receive purified / softened water or an aqueous liquid from the tub when it is sufficiently clean, eg, rinsing water.

Thus, the washing machine according to the invention preferably has a first and / or second storage tank for purified and / or softened water. The size of the storage container can vary widely. In general, their capacity for holding an aqueous liquid is about 70 to 90% of the amount of water provided in the washing machine for washing 6 to 8 kg of laundry. If, for example, 14 to 18 l of water are provided for the washing of 6 to 8 kg of laundry, the storage capacity of the storage containers in a preferred embodiment is 10 to 16 l.

The filtration device according to the invention is not limited as long as a desired filtration effect is achieved in one or more selected laundry treatment steps. Preferably, the filtration device is a reverse osmosis device, a nanofiltration device, an electrodialysis device and / or an ion exchanger.

In the washing machine according to the invention, at least two filtration devices of different average pore size and more preferably at least three filtration pre-filters are used. directions of different average pore size available. This means in particular that at least two filtration devices for the filtration of the aqueous liquid from the tub can be used before this then gets back into the tub. It has been shown that it is of particular advantage that at least one filtration device has a mean pore size of> 1 μηη, <0, 1 μηη or <0.01 μηη, or <0.001 μηη has.

In a particularly preferred embodiment, the washing machine has three filtration devices, of which a first filtration device over a mean pore size of> 1 μηι, a second filtration device over a mean pore size of <0, 1 μηη and a third filtration device over a mean pore size of <0 , 01 μηη features.

In a very particularly preferred embodiment, the washing machine has four filtration devices, wherein in addition a fourth filtration device with an average pore size of <0.001 μηη is present.

The washing machine of the present invention is a washing machine in the strict sense or a washer-dryer. In the following, the term washing machine is used for both devices.

The washing machine according to the invention comprises a program control, via which the programs to be executed are controlled. Preferably, the program controller is connected to a display device, which may additionally include input devices for inputting data by the user.

The ion exchanger used is preferably a synthetic resin ion exchanger, in particular a mixed bed ion exchanger. The ion exchanger can be present in a suitable cartridge ("ion exchanger cartridge"), which has inlet and outlet connections. The insertion of this cartridge in the washing machine and the removal of the cartridge can be done by means of a suitable opening and mounting device in the washing machine. For example, this cartridge can engage in corresponding inlet and outlet connections of the washing machine. A reverse osmosis device is a device which, in a physical method of membrane filtration called reverse osmosis, allows for concentration of solutes in liquid by reversing the natural osmosis process by applying pressure. In this way, water can be freed from dissolved constituents virtually maintenance-free, for example by desalting. Replacement or regeneration is eliminated. As a result of the reverse osmosis on the one hand purified, eg desalinated water ("soft water") and on the other hand more contaminated, eg salted up water ("hard water") is obtained, both collected separately and can be used or disposed of.

If, as a byproduct, water with a higher concentration of impurities (insoluble dirt particles, inorganic or inorganic molecules or ions) is obtained as a by-product, its further use depends on the type and concentration of the impurity. For example, if by-product water having a higher salt concentration has been produced (e.g., by performing reverse osmosis), it may be stored and used in a later washing process in one of the first rinses, preferably the first rinse. This has the advantage that detergent substances are more strongly bound by the salts and can be rinsed out in particle form. For this purpose, the washing machine according to the invention may advantageously comprise a storage container for water enriched with little or no interfering impurities and / or salts, e.g. a hard water tank. From this, the water stored therein can be mixed with e.g. increased salt concentration can be returned to the tub via appropriate lines. The feeder is also controlled by the program control.

The invention also relates to a method for treating laundry in a washing machine with a tub, a washing drum, a water supply system, a drain pump, a program control and at least one filtration device, wherein the at least one filtration device between the Lau- genbehälter and a supply line to the tub arranged and the washing machine is designed so that an aqueous liquid present in the tub can be at least temporarily filtered during a laundry treatment step by passing through the at least one filtration device and fed back to the tub. In the process, the aqueous liquid present in the tub is filtered at least temporarily during the laundry treatment step by passing through the at least one filtration device and fed back to the tub, wherein at least two filtration devices of different average pore size are present.

This means in particular that the washing machine used in the process according to the invention is designed so that an aqueous liquid present in the tub can be filtered at least temporarily during a laundry treatment step by passing through at least two filtration devices of different average pore size and can be returned to the tub.

In a preferred embodiment of this method, an aqueous liquid used in a laundry treatment step is passed through the inventively provided at least one filtration device and fed back to the tub depending on the type of laundry treatment step and / or a detected loading of the aqueous liquid by impurities and laundry treatment.

Moreover, in the process, it is preferable that the aqueous liquid is passed through one of at least three filtration devices, of which a first filtration device has a mean pore size, depending on the type of the laundry treatment step and / or a detected load of the aqueous liquid by impurities and laundry treating agent of> 1 μηι, a second filtration device over a mean pore size of <0, 1 μηη and a third filtration device has a mean pore size of <0.01 μηη.

With an average pore size of about 1 μηη eg hair, pollen and sand can be removed. With an average pore size of about 0.1 μηη most bacteria and dust and with an average pore size of about 0.01 μηη viruses, dyes and carbon black can be removed. Finally, with even finer filters, eg with an average pore size of about 0.001 μηη, for example, surface-active agents can be removed. For example, if the removal of dirt, viruses and bacteria is intended, but not the removal of detergent-active substances and other laundry treatment agents, then a range of filters of 0.005 to 5 μm is used. These filtration devices are preferably put into operation at an optimum time of the laundry treatment process. This time can be specified in a program control by using empirical values. In this case, various specifications of a user of the washing machine can be taken into account in the program control. For example, this may be considered by a user type and / or degree of contamination and type and amount of loading the laundry drum with laundry. Alternatively, the selection of one or more filtration devices and their operating time and operating time in the method according to the invention can also be carried out on the basis of measured values of one or more sensors for the type and amount of impurities or laundry treatment agent.

The filtration devices are generally arranged in parallel in the washing machine according to the invention, so that they can be targeted by the aqueous liquid flowing from the tub. In principle, however, a series connection would also be possible. For this purpose, generally controllable supply lines to the filtration devices are present in the washing machine, so that they can be switched on independently of one another.

The filtrate from the at least one filtration device is generally recycled continuously back into the tub.

In the method according to the invention, interruptions due to water changes or intensive dewatering cycles (spinning at higher speeds) can at least be reduced, if not avoided. Since parallel to a washing and / or rinsing process the water can be purified from its contents by suitable, ever finer filtration processes, namely a water change can be avoided. Depending on possible water losses, however, water can and is generally supplemented. A laundry treatment process to be carried out in the washing machine according to the invention generally begins with wetting of the items of laundry introduced into the laundry drum with water and bringing the laundry items into contact with a detergent. The cleaning process as well as the rinsing process now generally proceeds with constant reversing of the drum with reversing rhythms adapted to the respective type of textile and an occasional increase in the speed of the washing drum (<200 rpm, as shown in DE 10326551 A).

After a washing time corresponding to the degree of soiling of the laundry, which can be determined and determined manually or automatically after determination of contamination-relevant parameters by suitable sensors, a portion of the washing solution is, for example, continuously pumped through a medium pore filtration device (eg,> 1 μηι, microfiltration) and thereby cleaned by coarser particles. Dirt-bearing detergent ingredients can be freed from coarse dirt and again for cleaning the laundry available. The dissolved detergent components are retained and can continue to participate in the washing process. Due to the continuous discharge of dirt components, the washing-active substances of the washing solution are relieved and are available to the washing process again. As a result, the washing result can be improved. It is also possible in general to shorten the washing process while maintaining the previous washing performance.

After a reasonable time, the aqueous liquid, e.g. Washing liquor, preferably passed through a finer filter device (average pore size, for example, <0.1 μm ultrafiltration), in order also to remove larger molecules (for example surfactants, fats / waxes, degradation products from enzymatic reactions). As a result, a flushing process can thus be initiated without a water change being made.

This rinsing process is preferably subsequently terminated by the use of even finer filtration techniques (eg, <0.01 μm, nanofiltration, removal of divalent ions) or, for the conclusion, by reverse osmosis (removal of all dissolved constituents from the water). In the conventional laundry treatment process, a rinsing phase is generally carried out subsequent to the actual washing phase, which consists of one or more rinsing steps with water, generally two to three rinsing steps. The detergent components should be removed as completely as possible in the rinsing process. In order to achieve a fast and effective rinsing process, so far in each rinse fresh water is added to the previously dehydrated laundry. Due to the difference in concentration between dissolved substances in the fresh water on the other hand, there is an exchange / compensation of substances in laundry and water. The exchange process is better and faster, the greater the difference in the substance concentrations between laundry and water.

According to the invention, these sub-steps can be omitted, since in embodiments of the method according to the invention, the rinse water due to the filtration in at least two filtration devices is always clean and thus purified water gets to be washed laundry. There is always a high concentration gradient between laundry and rinse water. Thus, the laundry can be more quickly and effectively absorbed by ingredients of the laundry treating agent, e.g. Detergent, to be freed. The rinsing result can thus be improved or, while retaining the previous rinsing result, the rinsing process can be shortened.

With the last rinse water and the centrifugal water resulting from the final spin of the laundry, the filtration devices and / or the water-carrying components of the washing machine are preferably rinsed. As a result, accumulated dirt components of the filtration process (concentrates), which could in particular also lead to adverse hygienic effects removed.

In particular, in embodiments of the invention, the rinse water may be stored after cleaning and reused in the next washing process to achieve further water savings.

The amount of water to be used in the laundry treatment process generally depends on the load of the washing machine on laundry. The loading quantity can be determined by a measure known per se. In general, in a rinsing step for a laundry of 5 kg, a quantity of water of about 15 to 18 I needed. When carrying out the process according to the invention, this amount of water is reduced since, in principle, the aqueous liquid used in the washing phase can be used after at least one filtration. The invention has numerous advantages. Thus, due to generally reduced spin cycles, a relief of the structural components of the washing machine can be achieved.

The process according to the invention has the advantage that, while retaining the rinsing effect achievable by conventional rinsing, the total amount of water required for the rinsing phase can be significantly reduced. This is advantageously possible without lengthening the period of time for the entire treatment of the laundry in the washing machine. The water requirement may depend solely on the suction behavior of the laundry and the dead volume of the water-bearing parts of the washing machine. With additional storage of the filtered rinse water present at the end of the process, the consumption of fresh water can be further reduced. It must then only the loss of water (excessive suction when terry towels, removal of concentrate or retentate, system backwash) are compensated. Moreover, in certain embodiments, the invention makes it possible to reduce the load on the laundry with undesirable salts and other inorganic and / or organic substances, so that the use of fabric softener can be reduced or avoided. In addition, the invention is advantageous if the washing of laundry is to take place at a lowered washing temperature, for example at a temperature in the range of 15 to 20 ° C. Here it is sometimes feared that these low temperatures are not enough to kill germs. The present invention now also contributes to an improvement in hygiene, particularly in such washing processes, in that, in embodiments of the invention, germs can be separated from the washing or rinsing water by means of, for example, reverse osmosis or dialysis. Embodiments of the invention are illustrated in the accompanying drawings and are explained in more detail below with reference to Figures 1 and 2 of the drawing, wherein the first embodiment is no longer claimed. 1 is a schematic representation of a frontal sectional view of a first

Embodiment of a washing machine having a first and a second storage container for a relatively clean aqueous liquid, wherein only one filtration device is present; and Figure 2 is a schematic representation of a frontal sectional view of a second

Embodiment of a washing machine having three filtration devices and a second storage container.

In the schematic representation of Figure 1, the presently relevant parts of a washing machine in which a method to be described below can be performed, are shown. Other embodiments are conceivable. The washing machine has a lye container 1 in which a laundry drum 2 with laundry items 7 located therein can be rotatably mounted and operated by a drive motor 14. 3 means a rotation axis of the drum. In cooperation with specially shaped Wäschemitnehmern 4 and 5 Schöpfeinrichtungen for the wash liquor or rinse 6 an intensification of the flow of the laundry items 7 with wash or rinse water 6 is achieved. The washing machine has a liquor inlet system, which comprises a water connection for the domestic water network 8, an electrically controllable valve 9 and a supply line 10 to the tub 1, which is guided via an induction dish 1 1, from which the incoming fresh water can transport treatment agent in the tub 1 , In the tub 1 is a heater 13. Valve 9 and heater 13 can be controlled by a program control 12 in response to a program flowchart. A pressure sensor 15 is provided for the measurement of the hydrostatic pressure p in the tub 1.

There is provided a first filtration device 17 for purifying the water of relatively small organic and inorganic substances as well as for desalting water, which in this embodiment is a reverse osmosis device which is provided in a first filtration line 31 emerging from a central filtration line 23 and is arranged in front of the supply line 10 between dispenser 1 1 and 1 lye container.

In the first embodiment shown in Figure 1, the reverse osmosis results in a portion of purified water (herein also called "softened" water) collected in a first storage tank 24 for purified and / or softened water , For this purpose, the first filtration device 17 is connected to the first storage tank 24 via a first filtrate line 25. The first storage container 24 is in turn connected to the draft container 1 via a second filtrate line 27, so that filtered aqueous liquid (for example soft water) can be added as desired to the liquor container 1 and thus into the laundry drum 2.

Located between the first filtration device 17 and the first storage tank 24 is a first sensor 19 (e.g., a turbidity sensor or a conductivity sensor) for detecting a content of the water in impurities and / or salts of the water passing through the first filtration device 17.

In the first embodiment shown in FIG. 1, a storage container 18 connected to the first filtration device 17 via a first line 26 for water enriched with impurities and / or salts is additionally provided. Since the first filtration device 17 used in this embodiment is a reverse osmosis device, the water resulting from the filtration, which has a higher concentration of impurities and / or salts, is collected and stored for later use, eg for initial rinses , For this purpose, storage container 18 is connected via a second line 28 for enriched with impurities and / or salts of water and the supply line 10 to the tub 1. In addition, in the illustrated embodiment, a second storage container 22 is provided for liquid from the tub, which can store the water used in washing the laundry. This water can, in particular, be used for a later wash if it is the previously desalinated and then used during rinsing water. For this purpose, the second storage container 22nd connected via a storage line 34 with the central filtration line 23, which is ultimately connected via the supply line 10 to the tub.

In the lower region of the tub 1, there is a second sensor 20 (conductivity sensor, turbidity sensor) with which the content of the aqueous liquid used in the tub 1 of soluble and insoluble inorganic and organic substances can be determined. For this purpose, data stored in a memory of the program control 12 can be used for the relationship between the type and concentration of particulate impurities, salts, etc., and the conductivity or turbidity. 21 means a display means for indicating the presence of the condition L greater than or equal to L (max) in the water to be used or the condition S less than or equal to S (min) in the rinse water in the tub 1. After comparing a measured content S of inorganic and organic substances with a lower predetermined value S (min) and the determination of reaching or falling below S (min), the filtration of the aqueous liquid is stopped.

A pump 16 conveys the aqueous liquid 6 from the tub 1, so that it can be passed through the first filtration device 17. The pump 16 is in this embodiment part of the Laugenablaufsystems the washing machine. About the sewer line 36 16 wastewater can be disposed of by means of the pump.

Figure 2 is a schematic representation of a frontal sectional view of a second embodiment of a washing machine having three filtration devices and a second storage container.

The second embodiment shown in FIG. 2 differs from the first embodiment no longer claimed in FIG. 1 in that there are three filtration devices 17, 29 and 30. A second filtration device 30 in a second filtration line 33 has a mean pore size of> 1 μηι, a third filtration device 29 in a third filtration line 32 over a mean pore size of <0, 1 μηη and a first filtration device 17 in the first filtration line 31 via a average pore size of <0.01 μηη. In this case, in one embodiment of a method carried out in this washing machine, the aqueous liquid 6 is removed from the tub 1 by passage through the filtration devices 17, 29 and 30 filtered with increasing fineness. 2, a first sensor 19 is shown only for the third filtration device 29, with which the purity of the reaching from the third filtration device 29 filtrate can be determined. In the second embodiment shown in FIG. 2, a filtration bypass line 35 is provided, through which in the event of malfunctions of the filtration devices, the aqueous liquid conveyed by the pump 16 can pass back into the tub 1 via the dispensing dish 1 1.

Otherwise, in the second embodiment shown in Fig. 2, the same components of the washing machine are used as shown for Fig. 1, wherein like reference numerals will refer to like parts.

LIST OF REFERENCE NUMBERS

tub

washing drum

Rotary axis of the drum

laundry agitator

scooping devices

Wash, rinse water

laundry

Domestic water supply

Valve

Supply line (between the induction bowl and the tub)

dispenser tray

program control

heater

drive motor

pressure sensor

pump

first filtration device

Storage tank for impurity / salt enriched water, e.g. Hard water tank

first sensor (turbidity sensor, conductivity sensor)

second sensor (turbidity sensor; conductivity sensor)

display

second storage tank for purified and / or softened water from tub, e.g. backwash water

central filtration line

first storage tank for purified and / or softened water, e.g.

Soft water tank

first filtrate line

first line for enriched with impurities and / or salts of water 27 second filtrate line

28 second line for enriched with impurities and / or salts of water

29 third filtration device

30 second filtration device

31 first filtration line

32 third filtration line

33 second filtration line

34 storage line

35 filtration bypass line

36 sewer pipe

Claims

claims

Washing machine with a tub (1), a laundry drum (2), a water inlet system (8,9), a drain pump (16), a program control (12) and at least one filtration device (17,29,30), characterized in that the at least one filtration device (17,29,30) between the tub (1) and a supply line (10) to the tub (1) is arranged and the washing machine is designed so that in the tub (1) existing aqueous liquid (6) at least may be temporarily filtered during a laundry treatment step by passing through the at least one filtration device (17,29,30) and again supplied to the tub (1), wherein at least two different average pore filtration devices (17,29,30) are present.

Washing machine according to claim 1, characterized in that the washing machine is designed so that in the tub (1) existing aqueous liquid (6) at least temporarily during a laundry treatment step by passing through the at least one filtration device (17,29,30) filtered and again the tub (1) is supplied.

Washing machine according to one of the preceding claims, characterized in that the washing machine is designed to guide the aqueous liquid (6) through the at least one filtration device (17,29,30) during the entire duration of at least one laundry treatment step.

Washing machine according to claim 3, characterized in that the washing machine is designed to guide the aqueous liquid (6) through the at least one filtration device (17,29,30) during the entire duration of all the laundry treatment steps of a washing program.

5. Washing machine according to one of the preceding claims, characterized in that it comprises a first and / or second storage container (22,24) for purified and / or softened water.

6. Washing machine according to one of the preceding claims, characterized in that the at least one filtration device (17,29,30) is a reverse osmosis device, a nanofiltration device, an electrodialysis device and / or an ion exchanger.

7. Washing machine according to one of the preceding claims, characterized in that the at least one filtration device (17,29,30) has a mean pore size of> 1 μηη, <0, 1 μηη, <0.01 or <0.001 μηη has.

8. Washing machine according to claim 7, characterized in that it has three filtration devices (17,29,30), of which a second filtration device (17) over a mean pore size of> 1 μηι, a third filtration device (29) over a middle Pore size of <0.1 μηη and a first filtration device (30) has a mean pore size of <0.01 μηη has.

9. Washing machine according to one of the preceding claims, characterized in that it comprises a first sensor (19) for determining the functionality of the filtration device (17,29,30).

10. Washing machine according to one of the preceding claims, characterized in that it additionally comprises a display device (21) for displaying the functionality of the at least one filtration device (17,29,30).

1 1. A method for treating laundry in a washing machine with a tub (1), a laundry drum (2), a water supply system (8,9), a drain pump (16), a program control (12) and at least one filtration device (17, 29,30), wherein the at least one filtration device (17,29,30) between the tub (1) and a supply line (10) to the tub (1) is arranged and the washing machine is designed so that an aqueous liquid (6) present in the suds container (1) can be filtered at least temporarily during a laundry treatment step by passing it through the at least one filtration device (17, 29, 30) and returned to the suds container (1),

characterized in that in the tub (1) existing aqueous liquid (6) at least temporarily during the laundry treatment step by passing through the at least one filtration device (17,29,30) is filtered and fed back to the tub (1), wherein at least two filtration devices (17,29,30) of different average pore size are present.

12. The method according to claim 1 1, characterized in that the aqueous liquid (6) used in a laundry treatment step, depending on the type of laundry treatment step and / or a detected loading of the aqueous liquid with impurities and laundry treatment agent through the filtration device (17,29, 30) and returned to the tub (1) is supplied.

13. The method according to claim 12, characterized in that the aqueous liquid (6) depending on the type of laundry treatment step and / or a detected loading of the aqueous liquid (6) with impurities and laundry treatment agent by one of at least three filtration devices (17,29 , 30), of which a second filtration device (30) over a mean pore size of> 1 μηι, a third filtration device (29) over a mean pore size of <0, 1 μηη and a first filtration device (17) over a mean pore size of <0.01 μηη features.