Washing machine and method for operating a washing machine

Abstract

The invention relates to a filter device (16) for a washing machine (2), comprising a filter (18) with a raw side (22) having a filter inlet (20) and a clean side (28) having at least one filter outlet (24, 26), wherein the filter inlet (20) is designed for flow-conducting connection with a pump outlet (12) of a wastewater pump (14) of the washing machine (2) and one of the at least one filter outlet (24) is designed for flow-conducting connection with a drain line (10) of the washing machine (2) for discharging wastewater from the washing machine (2), characterized in that the filter device (16) is designed for installation in the washing machine (2).wherein a first filter outlet (24) of the clean side (28) of the filter (18) is configured for flow-conducting connection with the drain line (10) and a second filter outlet (26) of the clean side (28) of the filter (18) is configured for flow-conducting connection with a pump inlet (8) of the wastewater pump (14). Furthermore, the invention relates to a washing machine (2) and a method for operating the washing machine (2).

Description

[0001] Washing machine and method for operating a washing machine. The invention relates to a washing machine according to the preamble of claim 1 and a method for operating the washing machine. Filter devices for washing machines, washing machines equipped therewith, and methods for operating them are already known in the prior art in a multitude of embodiments. The known filter devices for washing machines comprise a filter with a raw side having a filter inlet and a clean side having at least one filter outlet, wherein the filter inlet is configured for a flow-conducting connection with a pump outlet of a wastewater pump of the washing machine, and one of the at least one filter outlet is configured for a flow-conducting connection with a drain line of the washing machine for removing wastewater from the washing machine.

[0002] Document WO 2019 / 045632 A1 discloses a filter device for use in a washing machine, comprising a filter, wherein the filter inlet is configured for a flow-conducting connection with a pump outlet of a washing machine's wastewater pump and the filter outlet is configured for a flow-conducting connection with a washing machine's drain line for removing wastewater from the washing machine. Documents EP 3 907 322 A1 and WO 2021 / 197937 A1 also disclose a corresponding filter device for use in or on a washing machine.

[0003] The invention thus addresses the problem of improving filter devices for washing machines, washing machines with filter devices, and methods for operating washing machines.

[0004] According to the invention, this problem is solved by a washing machine having the features of claim 1. Furthermore, this problem is solved by a method having the features of claim 9. Advantageous embodiments and further developments of the invention are described in the following dependent claims.

[0005] The advantage achievable with the invention lies particularly in the fact that filter devices for washing machines, washing machines with filter devices, and methods for operating washing machines are improved. Due to the inventive design of the washing machine and the method for operating the washing machine, the washing machine's wastewater system can be consistently separated from the washing machine's water inlet, thus effectively preventing, for example, the introduction of germs or similar contaminants into the washing machine's water inlet area. The continuous bypass flow through the wastewater pump and the filter during pumping out, i.e., draining the washing machine's tub, rinses the filter with cleaning solution and reduces, for example, biofilm formation. This effectively counteracts clogging of the wastewater pump.Furthermore, the continuous bypass flow prevents the wastewater pump from running in a "slurping" mode, which is comparable to running the pump dry. Instead, the wastewater pump always pumps liquid during operation, thus significantly reducing both the risk of the pump motor overheating and the pump's noise emissions.

[0006] In principle, the filter device according to the invention for the washing machine can be freely selected within wide suitable limits with regard to type, function, material, dimensions, and arrangement within the washing machine. The same applies to the washing machine according to the invention. For example, the invention can be advantageously used both in washing machines designed as household appliances and in commercial washing machines, i.e., washing machines for professional use. It is particularly advantageous if the filter of the filter device according to the invention is designed as a microparticle filter for removing microplastics or the like from the wastewater. Microplastics have become a very serious problem for the environment today, so the release of microplastics into the environment should be avoided as much as possible.

[0007] The washing machine's filter system includes a valve with a flow-conducting inlet connected to the pump outlet, a first flow-conducting outlet connected to the inlet for a flow-conducting connection to the filter inlet, and a second flow-conducting outlet connected to the inlet for a direct flow-conducting connection to the drain line. This allows the wastewater to be directed either directly into the washing machine's drain line or via the filter into the drain line.

[0008] A particularly advantageous embodiment of the washing machine according to the invention provides that the filter device has a combined inlet and outlet for the filter, wherein the inlet and outlet are connected to the first filter outlet in a flow-conducting manner, preferably that the inlet and outlet are simultaneously connected to the drain line in a flow-conducting manner, and particularly preferably that the inlet and outlet are connected to the drain line in a flow-conducting manner by means of a backflow preventer to prevent backflow from the drain line to the clean side of the filter. This ensures that the wastewater pump reaches its pumping capacity as quickly as possible and does not have to pump against a layer of gas and / or foam.Furthermore, the preferred embodiment of this further development has the additional advantage that, without significant additional structural effort, the drain line can also be vented and aerated simultaneously by means of the aforementioned ventilation. Moreover, according to the particularly preferred embodiment of this further development, the backflow preventer prevents wastewater from flowing from the drain line onto the clean side of the filter in an undesired manner.

[0009] A further advantageous embodiment of the washing machine according to the invention provides that the filter device has a restrictor arranged downstream of the second filter outlet in the direction of flow, preferably that the restrictor is arranged upstream of a return line for returning gases from the vent to a washing machine tub in the flow-conducting connection of the filter with the pump inlet. This return line is connected to the aforementioned flow-conducting connection and the combined air inlet and outlet. In this way, the ratio of the two partial flows of the wastewater—namely, the main portion flowing from the clean side of the filter into the drain line via the first filter outlet and the smaller portion flowing back from the clean side of the filter to the pump inlet of the wastewater pump via the second filter outlet—can be preset in a very simple manner, both in terms of design and manufacturing.Furthermore, the preferred embodiment of this further development has the additional advantage that pipe lengths can be saved for the return of gases from the ventilation and aeration to the washing machine's tub for the purpose of degassing by means of an emergency overflow connected to the tub in a flow-conducting manner known to those skilled in the art.

[0010] Another advantageous embodiment of the washing machine according to the invention provides that the filter device is designed as a single unit. This significantly simplifies warehousing, logistics, and the manufacturing of the washing machine equipped with it. Furthermore, it is possible to purchase the filter device according to the present embodiment as a complete unit from a supplier.

[0011] The filter is located in an upper section of the washing machine, at a height above the tub. This allows for a particularly simple, gravity-driven emptying of the filter after the tub has finished draining, both in terms of design and manufacturing.

[0012] A further advantageous embodiment of the washing machine according to the invention provides that the second filter outlet of the filter is connected to the pump inlet by means of a flow-conducting downpipe. Preferably, the downpipe is connected to an upper region of the tub by means of a connecting pipe rising from a downpipe outlet towards the tub inlet, in order to separate gas flowing towards the tub inlet from wastewater flowing towards the wastewater pump. This creates a very direct and therefore as short a flow-conducting connection as possible between the second filter outlet on one side and the pump inlet on the other. Furthermore, the design of the flow-conducting connection as a downpipe facilitates the gravity-driven flow of wastewater towards the pump inlet.Furthermore, the preferred embodiment has the additional advantage that gas contained in the flow is not undesirably carried along by the wastewater towards the pump inlet, but is released into the free environment via the connecting line, the lye container and the emergency overflow.

[0013] An advantageous embodiment of the aforementioned embodiment of the washing machine according to the invention provides that the return line is connected to the drain line in a flow-conducting manner by means of a drain line connection arranged in the flow direction between the restrictor and the drain line outlet, preferably that the internal diameter of the drain line downstream of the restrictor is larger than upstream of the restrictor. In this way, the venting of the filter, or of the filter and the drain line, is also connected to the emergency overflow via the drain line and the connecting line to it in a flow-conducting manner for the purpose of degassing. An additional flow-conducting connection from the aforementioned venting to the surrounding environment is not required.The preferred embodiment of this further development has the additional advantage that an unwanted carryover of gas flowing in the downpipe from the wastewater towards the wastewater pump is effectively prevented in a structurally and technically simple manner.

[0014] A particularly advantageous embodiment of the washing machine according to the invention provides that the washing machine is designed such that the filter can be removed directly from the washing machine. This allows for replacement or maintenance of the filter, for example, to remove the filter cake. Thanks to the invention, removing the filter from the washing machine is significantly simplified and less messy. This is because the filter is essentially emptied of wastewater before it is removed via the drainage system, for example, by means of the aforementioned drain pipe.

[0015] An embodiment of the invention is shown schematically in the drawing and is described in more detail below. It shows the single figure, Figure 1 shows an embodiment of the washing machine according to the invention with the filter device according to the invention for carrying out the method according to the invention in a partial side view.

[0016] In Fig. 1 An embodiment of the washing machine according to the invention, including the filter device according to the invention for carrying out the method according to the invention, is shown purely by way of example.

[0017] The washing machine 2, designed as a household appliance, comprises a tub 4, an emergency overflow 6 connected to an upper area of ​​the tub 4 in a flow-conducting manner, a wastewater pump 14 connected to the tub 4 by means of a pump inlet 8 and to a drain line 10 of the washing machine 2 by means of a pump outlet 12 in a flow-conducting manner for pumping wastewater (not shown) from the tub 4 into the drain line 10, and a filter device 16 for filtering the wastewater before it is introduced into the drain line 10.

[0018] The filter device 16 comprises a filter 18 designed as a microparticle filter for removing microplastics (not shown) from the wastewater, with a raw side 22 having a filter inlet 20 and a clean side 28 having at least one filter outlet 24, 26, wherein the filter inlet 20 is designed for flow-conducting connection with the pump outlet 12 of the wastewater pump 14 of the washing machine 2 and one of the at least one filter outlet 24 is designed for flow-conducting connection with the drain line 10 of the washing machine 2 for discharging wastewater from the washing machine 2.

[0019] According to the invention, the filter device 16 is designed for installation in the washing machine 2, wherein a first filter outlet 24 of the clean side 28 of the filter 18 is designed for flow-conducting connection with the drain line 10 and a second filter outlet 26 of the clean side 28 of the filter 18 is designed for flow-conducting connection with the pump inlet 8 of the wastewater pump 14.

[0020] The filter device 16 has a valve 30 designed as a 3-way valve, wherein the valve 30 has a valve inlet 32 ​​connected to the pump outlet 12 in a flow-conducting manner, a first valve outlet 34 which can be connected to the valve inlet 32 ​​in a flow-conducting manner for the flow-conducting connection with the filter inlet 20 and a second valve outlet 36 which can be connected to the valve inlet 32 ​​in a flow-conducting manner for the direct flow-conducting connection with the drain line 10.

[0021] Furthermore, the filter device 16 has a combined inlet and outlet 38 for the filter 18, wherein the inlet and outlet 38 is flow-conductingly connected to the first filter outlet 24, and wherein the inlet and outlet 38 is simultaneously flow-conductingly connected to the outlet line 10, namely in such a way that the inlet and outlet 38 is flow-conductingly connected to the outlet line 10 by means of a backflow preventer 40 to prevent a backflow (not shown) from the outlet line 10 to the clean side 28 of the filter 18.

[0022] In the present embodiment, the filter device 16 also has a throttle 42 arranged in the flow direction after the second filter outlet 26, wherein the throttle 42 is arranged in the flow-conducting connection of the filter 18 with the pump inlet 8 in the flow direction upstream of a return line 44 for the return of gases (not shown) from the vent 38 to the tub 4 of the washing machine 2.

[0023] Furthermore, the filter device 16 is designed here as a single unit. See also the dashed outline of the filter device 16 described above in the Fig. 1 , which illustrates this circumstance. Of course, embodiments of the invention are also conceivable in which the filter device is not arranged as a single unit, but, for example, distributed throughout the interior of the washing machine.

[0024] Furthermore, it is evident from the Fig. 1 It is shown that the filter 18 is located in an upper area of ​​the washing machine 2 at a height above the tub 4.

[0025] The second filter outlet 26 of the filter 18 is connected here to the pump inlet 8 by means of a flow-conducting downpipe 46, wherein the downpipe 46 is connected to an upper area of ​​the alkaline tank 4 by means of a connecting line 52 rising from a downpipe outlet 50 of the downpipe 46 towards the alkaline tank inlet 48 in a flow-conducting manner in order to separate gas flowing to a lye tank inlet 48 of the alkaline tank 4 and wastewater flowing to the wastewater pump 14.

[0026] In the present embodiment, the return line 44 is connected to the downpipe 46 in a flow-conducting manner by means of a downpipe connection 54 arranged in the flow direction between the throttle 42 and the downpipe outlet 50, wherein the clear diameter of the downpipe 46 in the flow direction after the throttle 42 is larger than in the flow direction before the throttle 42.

[0027] For the purpose of replacing or maintaining the filter 18, the washing machine 2 is also designed in such a way that the filter 18 can be removed from the washing machine 2 on site, i.e. at the installation location of the washing machine 2 at the end customer's premises.

[0028] The following describes the functioning of the washing machine according to the invention with the filter device according to the invention and the method according to the present embodiment with reference to the Fig. 1 explained in more detail.

[0029] If the draining of the washing machine's tub 4 is automatically started, for example by a program sequence of an automatic program of the washing machine 2, the valve 30 is automatically adjusted so that the pump outlet 12 is connected to the filter inlet 20 via the valve inlet 32 ​​and the first valve outlet 34. During the draining of the tub 4, i.e., the pumping process, the liquor, i.e., the wastewater, flows from the tub 4 via the pump inlet 8 to the wastewater pump 14. From the wastewater pump 14, the liquor passes through the valve 30 to the pipe side 22 of the filter 18. The combined venting and aeration 38 of the filter 18 ensures that the wastewater pump 14 does not have to pump against a layer of gas or foam.

[0030] The filtrate (not shown), i.e., the wastewater filtered by filter 18, from the clean side 28 is largely directed into the drain line 10 via the backflow preventer 40. The appropriately designed vent 38 and the backflow preventer 40 ensure that, firstly, no filtrate from filter 18 is conveyed through the vent 38, and secondly, no filtrate from the drain line 10 can flow back to the clean side 28 of filter 18. The flow rate of the filtrate is divided by the throttle 42, with a defined smaller portion being returned to the suction side of the wastewater pump 14, i.e., to the pump inlet 8, while the larger portion is directed into the drain line 10 and thus into the wastewater installation (not shown). Gases are returned from the vent 38 to the downpipe 46 via the return line 44.The air exchange between the vent 38 and the surrounding environment occurs via the drain pipe outlet 50, the tub 4, and the emergency overflow 6, using the connecting pipe 52. The height difference between the drain pipe outlet 50 and the tub inlet 48 ensures a separation of gas and liquor, thus preventing re-wetting of a load in washing machine 2 (i.e., laundry not shown, which is processed by washing machine 2).

[0031] The division of the wash water flow by means of filter 18 creates a continuous flow through filter 18 and wastewater pump 14. Wastewater pump 14 recirculates a portion of the wastewater, thus avoiding the so-called "drip" operation. This allows wastewater pump 14 to respond more quickly to increases in flow rate, and neither the wastewater pump 14 nor the entire wastewater system of washing machine 2 needs to be fully vented beforehand, as the wastewater pump 14 is already pumping. The partial flow through filter 18 ensures that it is continuously flushed with wash water during operation, effectively reducing biofilm formation. This, in turn, reduces clogging of wastewater pump 14.

[0032] After a predetermined period, valve 30 is automatically adjusted so that pump outlet 12 is directly connected to drain line 10 via valve inlet 32 ​​and the second valve outlet 36. Filter 18 is thus bypassed, and the wastewater pump 14 pumps directly into drain line 10. The non-return valve 40 prevents filter 18 from being filled from the clean side 28. The vent 38 aerates filter 18, and the wastewater stored in filter 18 can flow through the throttle 42 to the suction side of the wastewater pump 14, i.e., towards pump inlet 8, and is then pumped out of washing machine 2 by wastewater pump 14 and drain line 10. The wastewater from filter 18 is therefore not carried over into the next process step of the automatic program. The draining of the washing machine's tub 4 is automatically stopped.

[0033] Due to the inventive design of the filter device 16, the washing machine 2, and the method for operating the washing machine 2, the wastewater system of the washing machine 2 is consistently separated from the water inlet (not shown) of the washing machine 2, thus effectively preventing, for example, the introduction of germs or similar contaminants into the water inlet area of ​​the washing machine 2. During a pump-out cycle, i.e., the emptying of the washing machine's tub 4, the continuous bypass flow through the wastewater pump 14 and the filter 18 rinses the filter 18 with cleaning solution and reduces, for example, biofilm formation. This effectively counteracts clogging of the wastewater pump 14. Furthermore, the continuous bypass flow prevents the wastewater pump 14 from running intermittently, which is comparable to running dry.Instead, the wastewater pump 14 always pumps liquid, i.e. wastewater, during pumping, so that on the one hand the risk of overheating of a motor (not shown) of the wastewater pump 14 and on the other hand the noise emission of the wastewater pump 14 are significantly reduced.

[0034] The vent 38 ensures that the wastewater pump 14 quickly reaches its delivery capacity. The bypass or leakage flow is directed with the gas from the vent 38 in the downpipe 46 to the suction side of the wastewater pump 14. The liquid and gas phases are separated via the downpipe outlet 50 to the tubing 4. Only the gas phase is returned to the tubing 4. This reduces the risk of aerosol formation in a drum gap of a device located in the tubing 4 and in the Fig. 1The drum (not shown) is used to load washing machine 2 with laundry, thus improving the spin-drying result. The filter 18 is emptied via the second filter outlet 26 and the drain line 46. After switching the valve 30 at the end of the draining of the tub 4, the water carried over in the filter 18 can be pumped directly into the drain line 10 and thus into the house's water supply connected to it. This empties the filter 18, preventing it from leaking into the room where the washing machine 2 is located, for example, when the drain line 10 (designed as a drain hose) is dropped. Removing the filter 18 from the washing machine 2 is easier because it is now empty.

[0035] Since the filter 18 of the filter device 16 of the present embodiment is designed as a microparticle filter for removing microplastics or the like from the wastewater, it can effectively prevent, for example, the release of minute fibers that have detached from the textiles during the washing process when washing synthetic fibers into the environment via the wastewater discharged from the washing machine 2 through the drain line 10. Microplastics have become a very serious environmental problem today, so the release of microplastics into the environment should be avoided as much as possible.

[0036] However, the invention is not limited to the present embodiment. See, for example, the relevant explanations in the introductory section.

Claims

1. Washing machine (2), comprising a suds container (4), an emergency overflow (6) which is flow-conductingly connected to an upper region of the suds container (4), a waste water pump (14) which is flow-conductingly connected to the suds container (4) by means of a pump inlet (8) and to a waste water pipe (10) of the washing machine (2) by means of a pump outlet (12), which waste water pump is intended to convey waste water from the suds container (4) into the waste water pipe (10), and a filter device (16) for filtering the waste water before it is introduced into the waste water pipe (10), comprising a filter (18) having an untreated side (22), which has a filter inlet (20), and a clean side, (28) which has at least one filter outlet (24, 26), the filter inlet (20) being designed to be flow-conductingly connected to a pump outlet (12) of a waste water pump (14) of the washing machine (2), and one of the at least one filter outlet (24) being designed to be flow-conductingly connected to a waste water pipe (10) of the washing machine (2) in order to discharge waste water from the washing machine (2), a first filter outlet (24) of the clean side (28) of the filter (18) being designed to be flow-conductingly connected to the waste water pipe (10) and a second filter outlet (26) of the clean side (28) of the filter (18) being designed to be flow-conductingly connected to a pump inlet (8) of the waste water pump (14), and characterised in that the filter device (16) comprises a valve (30), the valve (30) having a valve inlet (32) which is flow-conductingly connected to the pump outlet (12), a first valve outlet (34) which is flow-conductingly connectable to the valve inlet (32) for a flow-conducting connection to the filter inlet (20), and a second valve outlet (36) which is flow-conductingly connectable to the valve inlet (32) for a direct flow-conducting connection to the waste water pipe (10).

2. Washing machine (2) according to claim 1, characterised in that the filter device (16) comprises a combined ventilation and venting system (38) for the filter (18), the ventilation and venting system (38) being flow-conductingly connected to the first filter outlet (24), preferably in that the ventilation and venting system (38) is simultaneously flow-conductingly connected to the waste water pipe (10), particularly preferably in that the ventilation and venting system (38) is flow-conductingly connected to the waste water pipe (10) by means of a non-return valve (40) in order to prevent backflow from the waste water pipe (10) to the clean side (28) of the filter (18).

3. Washing machine (2) according to any of claims 1 to 2, characterised in that the filter device (16) comprises a throttle (42) arranged downstream in the flow direction of the second filter outlet (26), preferably in that the throttle (42) is arranged in the flow-conducting connection of the filter (18) to the pump inlet (8) upstream, in the flow direction, of a return pipe (44) which is flow-conductingly connected to the aforementioned flow-conducting connection and the combined ventilation and venting system (38) in order to return gases from the ventilation and venting system (38) to a suds container (4) of the washing machine (2).

4. Washing machine (2) according to claim 3 characterised in that the filter device (16) is a structural unit.

5. Washing machine (2) according to any of claims 1 to 4, characterised in that the filter (18) is arranged in an upper region of the washing machine (2), at a height above the suds container (4).

6. Washing machine (2) according to any of claims 1 to 5, characterised in that the second filter outlet (26) of the filter (18) is connected to the pump inlet (8) by means of a downpipe (46), preferably in that the downpipe (46) is flow-conductingly connected to an upper region of the suds container (4) by means of a connecting pipe (52) ascending from a downpipe outlet (50) of the downpipe (46) towards the suds container inlet (48) for the purpose of separating gas flowing to a suds container inlet (48) of the suds container (4) and waste water flowing to the waste water pump (14).

7. Washing machine (2) according to claims 3 and 6, characterised in that the return pipe (44) is flow-conductingly connected to the downpipe (46) by means of a downpipe connection (54) arranged in the flow direction between the throttle (42) and the downpipe outlet (50), preferably in that an inside diameter of the downpipe (46) in the flow direction downstream of the throttle (42) is larger than in the flow direction upstream of the throttle (42).

8. Washing machine (2) according to any of claims 1 to 7, characterised in that the washing machine (2) is designed such that the filter (18) can be removed from the washing machine (2) on-site.

9. Method for operating a washing machine (2) according to any of claims 1 to 8, according to which the method comprises the following steps in the specified order: - automatically starting drainage of the suds container (4), - automatically adjusting the valve (30) such that the pump outlet (12) is flow-conductingly connected to the filter inlet (20) by means of the valve inlet (32) and the first valve outlet (34), - after a predetermined period of time, automatically adjusting the valve (30) such that the pump outlet (12) is directly flow-conductingly connected to the waste water pipe (10) by means of the valve inlet (32) and the second valve outlet (36), - automatically terminating the drainage of the suds container (4).

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