EP2175062B1 - Method for cleaning an added lye in a washing or cleaning machine and machine for carrying out this method - Google Patents

Description

The invention relates to a method for cleaning a waste liquor of a washing or cleaning machine with a container for washing or cleaning household items, such as laundry or crockery, using lyes, which consist essentially of water and surfactant-containing detergents, a fresh water inlet, a wastewater drain and Have a drain pump, which allows to pump the liquor from the container via a Abpumpstrang in the waste water drain, and a subsequent washing or cleaning machine.

There are no immediate suggestions on the subject. All relevant prior art ( DE 195 11 784 A1 ; DE 197 09 085 A1 ; DE 198 57 310 A1 ) is limited to proposals for the reuse of used in washing or cleaning machines working fluid. Sun strikes DE 195 11 784 A1 prior to caching leached from the container of the last rinse cycle for subsequent use. This subsequent use can be a new wash cycle or, in the case of a washing machine also set up for drying, use as cooling water in a condenser.

This in DE 197 09 085 A1 On the other hand, the proposed method also uses the pumped-off washing liquor from a washing section of the laundry treatment program. In this case, the respectively pumped out liquor should be fed to a filtration process (reverse osmosis, micro, ultra or nanofiltration), while a further treatment section is carried out in the washing machine. Thereafter, the filtered liquor is supplied to the subsequent treatment section. Both the last used liquor and the permeate accumulated in the filter are finally fed unfiltered to the wastewater drain.

The document WO2005051157 A1 shows a dishwasher with a system for water treatment comprising a water treatment tank, which can accommodate at least a portion of the rinsing liquid used during the washing operation of the dishwasher, wherein in the water treatment tank during a water treatment phase using microorganisms, the impurities contained in the rinse liquid are at least partially biodegraded.

In the DE 198 57 310 A1 described drum type washing machine has an additional tank, which should replace a ballast weight in the filled state on the one hand. On the other hand, it should serve for the storage of supplied from the fresh water supply fresh water, which should be preheated even by an additional heating. In addition, the last rinse water can be stored for a subsequent washing section.

All proposals have the disadvantage that the leach finally removed from the washing machine is unpurified. Not a few users of washing machines make sure that they conduct as few environmentally harmful alkalis into the public wastewater or their own wastewater treatment plant. With the previously known washing or cleaning machines, they can not meet this claim.

The invention is therefore based on the object to provide a method of the type mentioned above and a suitable washing or cleaning machine, which can serve the needs of environmentally conscious customers in the described question. However, possibilities for recycling used liquors should not be ruled out.

According to the invention, the above-described object is achieved by the characterizing features of claim 1, characterized in that the surfactants contained in the waste liquor are degraded by catalysis and the still remaining in the waste liquor contained undissolved residues are collected in a filter. Through these measures, environmentally harmful surfactants can be kept away from the wastewater of washing or cleaning machines for the first time. At the same time, other unresolved residues are retained and the spent liquor is thus reusable.

If, according to an advantageous embodiment of the method according to the invention, depending on the purity of the waste liquor after the filter, the waste liquor is optionally passed into the waste water drain or in a storage tank, the spent liquor can be stored for recycling. For this purpose, it is particularly advantageous if, according to a further embodiment of the method according to the invention, either fresh water or purified waste liquor is supplied to the container from the storage tank.

To carry out the process according to the invention, a corresponding washing or cleaning machine according to the invention in Abpumpstrang a catalyst for the surfactants used and a filter for entrained in the waste liquor residuals. The waste liquor contains unused surfactants and undissolved residues that pollute the effluents if they were not removed from the waste liquor or at least predominantly removed. The derived from the container Waste liquor is first freed according to the invention in the catalyst of residual surfactants, which are also partly converted into undissolved residues. Thereafter, the waste liquor is fed to a filter which is adapted to separate undissolved residues from the liquor. The at least predominantly liberated from the residues waste liquor can then be routed through the wastewater discharge to the public sewer network, without endangering this ecologically.

Instead of directing the purified waste liquor in the public sewer network, however, the washing or cleaning machine can be trained according to the invention in such a way that between the filter and the wastewater drain an adjustable Laugenverteileinrichtung is arranged, whose input with the filter whose one output with the Wastewater drain and the other, alternatively acting output is connected to a storage tank. In that case, the waste liquor, which can be recycled again, can then be temporarily stored for further use.

In a particularly advantageous embodiment of the washing or cleaning machine according to the invention, the storage tank has an output which is connected via a return pump with an adjustable fresh water distribution device whose one input to the fresh water inlet, the other, alternatively acting input to the return pump and the output to the container connected is. In this way, the container can be fed either with fresh water or with reusable waste liquor.

A decision as to whether fresh water or purified spent liquor is to be used may be made dependent on the quality of the spent liquor attached in the connection from the filter to the waste water drain being sufficiently good and that a level sensor mounted in the holding tank has a sufficiently large amount of storage has signaled from purified waste liquor.

Of course, since a catalyst has a limited life, it is advantageous if according to another embodiment of the invention, the catalyst has a capacity sufficient for a calculated life of the washing or cleaning machine. In the event that the capacity, z. B., because of intensive use of the washing or cleaning machine is still insufficient, the catalyst can be replaced by the customer service.

The filter can according to a development of the invention also have a function by which he holds back soluble components of the waste liquor. For this purpose, a component of the filter can be constructed as an activated carbon filter. To renew the filter function, the filter can also be made interchangeable or regenerable.

Of particular advantage is an additional design feature of the washing or cleaning machine according to the invention, that in the connection from the filter to the wastewater drain a sensor is attached, which can determine the quality of the waste liquor. This makes it possible to decide whether, depending on the quality of the waste liquor, it is conducted into the storage tank or into the waste water drain. Furthermore, it is possible to monitor the functionality of the catalyst and / or the filter by means of the sensed waste liquor quality.

With reference to an embodiment of a washing machine shown schematically in the drawing, the inventive method and a washing or cleaning machine for carrying out the method are explained in more detail.

In the drawing, a laundry drum 1 is shown, which is rotatably mounted in a container, namely a tub 2 of a washing machine otherwise not shown, about a horizontally arranged axis 3. At the bottom of the tub 2 a lye drain 4 is attached, which is connected via a drain line 5 with a drain pump 6. These are common components of a washing machine. Normally, the discharge-side outlet of the drain pump is directly connected to a waste water outlet 7.

In the washing machine according to the invention, a catalyst 9 and a filter 10 are connected in the line 8 between the pressure side of the drain pump 6 and the waste water outlet 7. Furthermore, this compound also contains a Laugenverteileinrichtung 11, a two-way valve through which the waste liquor optionally in the waste water drain 7 or - as shown - can be passed to a storage tank 12. This decision is made by a controller 13, as explained below.

At the bottom of the storage tank 12, a line 14 opens with a return pump 15 whose pressure side is connected to the input of a fresh water distribution device 16. In the illustrated setting of Fresh water distribution device 16, the line 14 and the pump 15 connections to the fresh water inlet 17 of the tub 2. The other input of the fresh water distribution device 16 is connected to the fresh water network 18. When changing the setting of the distribution device 16, the fresh water network 18 is connected to the fresh water inlet 16.

In line 8, a sensor 19 is arranged, through which the quality of the waste liquor in this line 8 can be measured in terms of their ecologically harmful components, such as the proportions of surfactants and relevant solids. These measurement results are permanently reported to the control device 13. In addition, level signals are supplied from the level sensor 20 in the storage tank 12 to the controller 13. From these signals and the known progress of the program stored in the control device 13, the control device can decide on the respectively required setting of the liquor distribution device 11 and / or the fresh water distribution device 16.

In the course of a treatment program, the process for purifying the waste liquor can be easily performed. After a treatment section in the program, for example, lye pumped out of the tub 2 by the drain pump 6. This waste liquor is freed of unconsumed surfactants in the catalyst 9 and fed to the filter 10, where the waste liquor is freed from suspended residues. If a filter stage is included, which can detect dissolved residues, eg. As an activated carbon filter, such residues are removed. Thereafter, the waste liquor flows through the conduit section 8, in which the sensor 19 is mounted. He now measures the concentration of remaining in the waste liquor and ecologically questionable residues and reports the measurement result to the controller 13th

The control device 13 can decide on the basis of a comparison with predetermined threshold values and on the basis of the upcoming program section, whether the waste liquor can or should be supplied to the waste water outlet 7 or the storage tank 12. Accordingly, the alkali distribution device 11 is controlled. However, if the storage tank 12 is already filled, the level sensor 20 reports this circumstance to the control device 13, which then sets the liquor distribution device 11 unconditionally for discharging the waste liquor through the waste water outlet 7.

If a program step is pending during the program sequence, which requests the supply of fresh water for the tub 2, the level sensor 20 is first queried about the liquor level in the storage tank 12. If the liquor level is sufficient, the control device 13 can switch the fresh water distribution device 16 to the input which is connected to the pressure side of the return pump 15 and switch on the return pump 15. As a result, cleaned waste liquor is removed from the storage tank 12 and supplied to the tub 2 until the liquor level is no longer sufficient for this. Is then still fresh water for the filling in the tub 2 required, then the controller 13 switches the fresh water distribution device 16 back to the fresh water supply 18 and leaves the fresh water supply as long until the level in the tub 2 - a corresponding level measuring required - sufficient. In the case of a level from the outset in the storage tank 12, the latter takes place in the same way.

If the quality sensor 19 detects a filter quality of the waste liquor which is insufficient both for recycling and for discharging the waste liquor, then the waste liquor outlet 7 is controlled only if the control device can not decide to interrupt the program flow at all. In addition, the user of the washing or cleaning machine is signaled that the catalyst 9 and / or the filter 10 must be cleaned, regenerated and / or replaced or should. If necessary, the machine is also locked for further use in connection with lye.

Finally, in order to remove residues from the filter 10 and / or the storage tank 12, drains are provided on these vessels, which are indicated by valve-controlled drain lines 21 and 22.

In the case of a dishwasher, the features described can be used in an adequate manner, on the one hand to protect sewage from polluting waste liquor and on the other hand to use waste liquor with sufficient cleaning for subsequent processes.

Claims (15)

1. Method of cleaning a solution of a washing or cleaning machine with a container (2) for washing or cleaning domestic articles, such as laundry or dishes, with use of solutions consisting substantially of water and washing agents containing surfactants, a fresh water feed (17), a solution pump (6) and a waste water drain (7), which allows the solution to be pumped out of the container (2) by way of pumping-out pipework (8) into the waste water drain (7), characterised in that the surfactant present in the waste solution is broken down by catalysis and the undissolved residues thereafter still present in the waste solution are filtered out.
2. Method according to claim 1, characterised in that depending on the purity of the waste solution after the filtering the waste solution is selectably conducted into the waste water drain (7) or stored.
3. Method according to claim 2, characterised in that selectably fresh water or cleaned and stored waste solution is fed to the container (2).
4. Washing or cleaning machine for performing a method according to any one of the preceding claims, comprising a container (2) for washing or cleaning domestic articles, such as laundry or dishes, with use of solutions, which substantially consist of water and washing agents containing surfactant, a fresh water feed (17), a waste water drain (7) and a solution pump (6), which allows the solution to be pumped out of the container (2) via a pumping-out pipework (8) into a waste water drain (7), characterised in that a catalyser (9) for the used surfactant and a filter (10) for residues entrained in the waste solution are arranged in the pumping-out pipework (8).
5. Washing or cleaning machine according to claim 4, characterised in that arranged between the filter (10) and the waste water drain (7) is a settable solution distributing device (11), having an input connected with the filter (10), one output connected with the waste water drain (7) and another, alternatively effective output connected with a storage tank (12).
6. Washing or cleaning machine according to claim 5, characterised in that the storage tank (12) has an output connected by way of a return pump (15) with a settable fresh water distributing device (16), having an input connected with a fresh water mains connection (18), another, alternatively effective input connected with the return pump (15) and an output connected with the fresh water input (17) to the container (2).
7. Washing or cleaning machine according to any one of claims 4 to 6, characterised in that the catalyser (9) has a capacity sufficient for a calculated service life of the washing or cleaning machine.
8. Washing or cleaning machine according to claim 7, characterised in that the catalyser (9) is installed to be capable of exchange.
9. Washing or cleaning machine according to any one of claims 4 to 8, characterised in that the filter (10) includes an activated carbon filter.
10. Washing or cleaning machine according to any one of claims 4 to 9, characterised in that the filter (10) is designed to be exchangeable.
11. Washing or cleaning machine according to any one of claims 4 to 9, characterised in that the filter (10) is designed to be regeneratable.
12. Washing or cleaning machine according to any one of claims 4 to 11, characterised in that a sensor (19) able to determine the quality of the waste solution is mounted in the connection (8) from the filter (10) to the waste water drain (7).
13. Washing or cleaning machine according to claim 12, characterised in that the sensor (19) is connected with a control device (13) which can control the solution distributing device (11) in dependence on the signal of the sensor (19).
14. Washing or cleaning machine according to claim 12 or 13, characterised in that the control device (13) is connected with the fresh water distributing device (16) and with the return pump (15), which are controllable by the control device (13) in dependence on a presetting of the control device (13) in the sense of feed of fresh water from the fresh water mains connection (18) or feed of cleaned solution from the storage tank (12).
15. Washing or cleaning machine according to claim 13 or 14, characterised in that the storage tank (12) includes a level sensor (20) connected with the control device (13).

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