DE19709085C2 - Method of washing laundry using a filtration method - Google Patents

Description

The invention relates to a method for washing laundry, in particular in a Household washing machine, in which the laundry in a tub during a Washing section with washing liquid and during subsequent rinsing sections Rinsing liquid is treated and at the end of each wash or rinse section of the tub is emptied, the washing liquid and / or the rinse liquid at least one rinsing section are emptied into a collecting container and after preparation by a reverse osmosis, micro, ultra, or nanofiltration process can be reused with temporary storage in a storage container.

A method of the type mentioned or a washing machine for performing a Such a method is known from EP 578 006 A1. This is done in one wash used washing and rinsing liquid prepared by different filtration processes and, depending sorted by quality, stored in different containers and again in the next wash used. The storage of all the liquid until the next wash is very good expensive because large containers have to be provided for this. There is also, depending on Duration of the period from one to the next wash cycle, the risk of contamination of the stored liquid.

DE 38 05 565 A1 describes a method and a device for cleaning ver dirty parts known. Both the method and the device are optionally in a washing machine or dishwasher. It will be the one in a cleaning pro filtered section of liquid used with detergent or dishwashing liquid deprive her of fat and dirt. The filtered lye is then saved to it to be able to use it again in a later, newly executed program. Between the execution of two programs can take several days, for example an interim vacation of the user is the above procedure for household washing machines not applicable, since there is a risk of contamination.

The invention thus presents the problem of a method of to disclose the type mentioned, in which a storage of liquid over a longer period. Periods is not necessary.

According to the invention, this problem is solved by a method with that in claim 1 specified features solved. An advantageous embodiment of the invention The method is characterized in that the processed washing liquid is a later rinse section of the same program flow is fed to that  Rinsing section follows, which includes emptying the rinsing liquid into the collecting container (claim 2) or that the processed rinsing liquid of the rinsing section is transferred to the later one Rinsing section following rinsing section is supplied (claim 3). This can be done without additional Intensive filtering of the washing or rinsing liquid is carried out, which means that a high proportion of permeate is obtained due to the long filtration times.

It has also proven to be advantageous to use the cross-flow process feed, the liquid to be filtered in a circuit through the collecting container and the filter is guided (claim 4). This extends the service life of the filter membrane.

In addition, the use of at least four rinsing sections (claim 5) and in particular in the Rinsing sections with a reduced amount of rinsing liquid (claim 6) for a good washing result simultaneous water saving and short program times.

In order to further improve the quality of the treated rinsing liquid, the treated liquid before using it as a rinsing liquid Reduction in alkalinity can be supplied (claim 7).

An embodiment of the invention is shown purely schematically in the drawings and is described in more detail below. Show it:

Fig. 1 shows the method according to the invention for washing laundry using a block diagram.

Fig. 2 shows the water-carrying parts of an automatic washing machine for carrying out the washing process according to the invention

The method according to the invention (see FIG. 1) consists of a main wash cycle (HW), which is followed by four rinsing sections (SP1... SP4). At the end of each program section, the washing or rinsing liquid is emptied from the tub and reprocessed by a reverse osmosis, micro, ultra or nanofiltration process (F) during the next program section. In the next but one program section, the permeate obtained in this way is reused. As a result, from the second rinsing section only the concentrate discarded during filtering has to be replaced with tap water (approx. 10%), which leads to considerable water savings. A further water saving is achieved in that a reduced amount of water can be used due to the washing of the laundry four times. This reduces the tap water requirement in the first rinsing section (SP1). When using a micro, ultra or nanofiltration process, the alkalinity of the treated rinsing water can be reduced from rinsing section SP2 by adding a neutralizer, for example vinegar or citric acid. In the case of a reverse osmosis, this is not necessary due to the deionization of the permeate.

Fig. 2, the water-carrying parts schematically shows an automatic washing machine for carrying out the washing process according to the invention. The water is fed into the tub ( 1 ) via a detergent dispenser ( 2 ), through which the necessary detergent and water treatment agent can be added. The washing or rinsing liquid is emptied into a collecting container ( 4 ) via a valve ( 3 ) at the end of the program sections. From there, the liquid in the circuit ( 5 ) is passed through a cross-flow filter ( 6 ). The cross-flow filter ( 6 ) works according to one of the filter processes described above in order to filter out even the smallest particles. In order to guarantee a sufficient filter speed and a high proportion of permeate, a powerful filter pump ( 7 ) is used, which increases the liquid pressure to up to ten bar depending on the filter process. The unfiltered concentrate K is emptied into the drain ( 9 ) at the end of each wash cycle with the rinsing liquid of the fourth rinsing section via a drain pump ( 8 ).

The permeate P obtained in the cross-flow filter ( 6 ) is collected in a storage container ( 10 ) and from there, if necessary, for reuse via a storage pump ( 11 ) through the detergent dispenser box ( 2 ) in the tub ( 1 ). To clean the storage tank ( 10 ) and possibly to supplement the permeate P, a tap water connection ( 12 ) is led to the storage tank ( 10 ). Another tap water connection ( 13 ) is used for backwashing the filter membrane ( 14 ). When backwashing, it must be ensured that the water path between the storage tank and the filter is closed (valve ( 15 )) in order to prevent pressure reduction.

The collecting container can be arranged to reduce the ballast mass necessary for balancing the unbalance ( 1 ) (not shown). In this case, to avoid uncontrollable vibrations, it must be ensured that the collecting container ( 4 ) is always completely filled when spinning.

Claims (7)

1. A method for washing laundry, in particular in a household washing machine, in which the laundry is treated in a tub ( 1 ) during a washing section (HW) with washing liquid and during subsequent rinsing sections (SP1 ... SP4) with washing liquid and in which At the end of the respective washing or rinsing section (HW, SP1... SP4), the tub 1 is emptied, the washing liquid and / or the rinsing liquid of at least one rinsing section being emptied into a collecting tank ( 4 ) and after preparation by reverse osmosis -, Micro, Ultra, or Nanofiltration process (F) with intermediate storage in a storage container ( 10 ) can be reused, characterized in that the processed washing or rinsing liquid is fed to a later rinsing section (SP2... SP4) of the same program sequence , 2. The method according to claim 1, characterized in that the processed washing liquid is fed to a later rinsing section (SP2... SP4)) of the same program sequence, which follows that rinsing section (SP1) that empties the rinsing liquid into the collecting container ( 4 ) includes. 3. The method according to claim 1, characterized, that the prepared rinsing liquid of the rinsing section (SP1) is transferred to the later rinsing section (SP2) following rinsing section (SP3, SP4)) is supplied. 4. The method according to any one of claims 1 to 3, characterized in that the treatment takes place via a cross-flow filter (F; 6), the liquid to be filtered in a circuit ( 5 ) through the collecting container ( 4 ) and the filter (F; 6) is performed. 5. The method according to any one of claims 1 to 4, characterized by the use of at least four rinsing sections (SP1 ... SP4). 6. The method according to claim 5, characterized, that in the rinsing sections (SP1 ... SP4) a compared to conventional rinsing sections reduced amount of rinsing liquid is used.   7. The method, in particular according to one of claims 1 to 6, characterized, that the treated liquid has a neutralizer before it is used as a rinsing liquid Reduction in alkalinity is supplied.