EP3004448B1 - Method for operating a washing machine achieving an improved residual moisture content of the laundry, and washing machine suitable therefor - Google Patents

Description

The invention relates to a method for operating a washing machine with an improved residual moisture and a particularly suitable for carrying out this method washing machine.

The publication EP 2 246 469 A1 shows a washing machine comprising a rotatable drum, a tub in which the drum is arranged, and a circulation pump for pumping water from a drain region of the tub via a circulation line back into the tub.

A washing program in a washing machine with a drum rotatably mounted in a tub generally has a rinsing phase with several spin stages after a wetting phase and a washing phase. With a last spin step, as much water as possible should be removed from the wash, so that the washed laundry, which may have been treated with a fabric softener, must not be removed with dripping wet. In particular, it is desirable that the residual moisture still present in the laundry after the spin phase, which is frequently also referred to as "slip moisture content," be as low as possible. This is generally achieved by a good separation of the water when spinning at a high speed of the drum. In this case, the centrifugal force forces the water from the laundry through drainage holes of the drum to the outside into a space between the drum and the tub, where it ideally flows into a lower part of the tub, a region comprising a heater, also referred to as a "heater bag" , From the radiator pocket, this water can then be pumped out for disposal or reuse.

In the known methods remains after the last spin step still a relatively high residual moisture.

From the EP 2 390 397 A1 is a method for carrying out a washing cycle and a subsequent drying cycle in a washer-dryer with a heat pump in which at least one final rinse phase of the wash cycle is performed using heated water to increase the temperature within the tub. This is to solve the problem of inefficient operation during the initial phase of a drying cycle, which arises because the heat pump system takes a certain time to reach a state of equilibrium. Due to the flushing with the heated water, the temperature inside the tub and drum is relatively high, so that the initial heat exchange
increased at the evaporator of the heat pump. This should reduce the time to reach an advantageous state of equilibrium when operating the heat pump. The heating of the water can be done by the usual in a washing machine heater or by an additional hot water supply or by a renewable energy source such as solar energy. The temperature of the heated water can be between 40 and 80 ° C.

The EP 2 503 048 A1 describes a method for washing in a washing machine and a corresponding washing machine. The method comprises between the rinsing phase and the spin phase a heating phase in which the laundry is heated. By heating the laundry, its water retention capacity is to be reduced by reducing the surface tension of the water in the laundry and by stretching the fibers, so that as a result, at the end of the spin phase, washing with a reduced residual moisture is obtained. For this purpose, the water wetting the laundry can be heated. Preferably, the heating phase comprises a direct heating of the laundry, more preferably by heating with infrared radiation.

However, these known methods still require comparatively much water and energy.

Against this background, it is an object of the present invention to provide a process for rinsing laundry which is improved with regard to the consumption of water and / or energy and which enables a low residual moisture content of the washed and thrown laundry after a final spin phase. The object of the invention was also to provide a particularly suitable for this purpose washing machine.

The solution of this object is achieved according to this invention by a method for rinsing laundry in a washing machine with the features of the corresponding independent claim and the washing machine of the corresponding independent claim. Preferred embodiments of the method according to the invention are listed in corresponding dependent claims. Preferred embodiments of the method according to the invention correspond to preferred embodiments of the washing machine according to the invention, although this is not explicitly stated herein.

1. (a) die Pumpe eingeschaltet und eine im Laugenbehälter befindliche freie Flotte abgepumpt wird;
2. (b) die Pumpe anschließend abgeschaltet wird und bei abgeschalteter Pumpe die Trommel mit einer Schleuderdrehzahl ω₁ betrieben wird, um den Feuchtigkeitsgehalt der feuchten Wäsche aus Schritt (a) zu verringern und das dabei ausgetriebene Wasser im Laugenbehälter aufzufangen, so dass für die Wassermenge q im Laugenbehälter q = q_col gilt;
3. (c) für den Fall, dass die im Schritt (b) aufgefangene Wassermenge q_col < q_set ist, der Laugenbehälter mit Wasser aus der Wasserversorgung aufgefüllt wird, bis für die Wassermenge q im Laugenbehälter q ≥ q_set gilt;
4. (d) die Wassermenge q im Laugenbehälter auf eine vorgegebene Temperatur T_set erhitzt wird;
5. (e) das erhitzte Wasser aus Schritt (d) in der Wäsche verteilt wird; und
6. (f) die Trommel mit einer Schleuderdrehzahl ω₂ betrieben wird, um in der Wäsche verteiltes erhitztes Wasser aus Schritt (e) aus der Wäsche zu treiben und abzupumpen.

The invention thus relates to a method for rinsing laundry in a washing machine with a control device for controlling a program sequence, a rotatably mounted in a tub drum, a heater, a pump and a drive motor for the drum, wherein subsequent to a washing phase in a Rinsing phase with one or more rinsing steps at least in the last rinsing step after the addition of the last rinse water portion in the tub and the rinsing of the laundry

1. (a) the pump is switched on and a free liquor contained in the tub is pumped out;
2. (B) the pump is then switched off and with the pump off, the drum is operated at a spin speed ω ₁ to reduce the moisture content of the wet laundry from step (a) and to catch the water expelled in the tub, so that for the amount of water q in the tub q = q _col applies;
3. (c) in the event that the quantity of water collected in step (b) is q _col <q _set , the tub is filled with water from the water supply until q ≥ q _set applies to the amount of water q in the tub;
4. (D) the amount of water q is heated in the tub to a predetermined temperature T _set ;
5. (e) distributing the heated water from step (d) in the laundry; and
6. (f) the drum at a spin speed ω ₂ operates to drive distributed in the wash water heated from step (e) from washing and to pump.

Preferably, the pumping is performed in step (a) until a delivery rate of the pump has dropped to 10%, in particular 8% and particularly preferably 5% of its initial value p _init .

Alternatively or in addition to this, in a preferred embodiment of the method according to the invention, the pumping in step (a) is carried out until the pump detects the beginning of the promotion of a gas / air mixture. In general, this is associated with a relatively large fluctuation of the delivery rate.

During this pumping free liquor is pumped out, ie the liquid which is not bound by the laundry.

The wet laundry in the drum after pumping the free liquor may still have too much water, "too much" meaning that the laundry will bind more water than is required for subsequent heating of the laundry in step (d). In a preferred embodiment of the method, therefore, when the pump is switched on, a slight spinning with the drum is carried out in a step (a1). Preferably, in this case, in step (a1), the drum (2) is operated for a period of at most one minute with a number of revolutions ω of at most 500 revolutions / min.

In the method according to the invention, a heating of the laundry is achieved in order to reduce the water retention capacity of the laundry. In this case, the predetermined temperature T _set is generally in the range of 40 ° C to 95 ° C. Depending on the type and amount of laundry, the predetermined temperature T _set can be suitably selected in this area.

In a preferred embodiment of the method, a relationship between the predetermined amount of water q _set and a loading amount w _w is therefore stored in the control device of the washing machine used. Here, in general, the amount of water q _{set is} lower, the lower the amount of loading w _w with laundry.

The loading amount w _w can be determined automatically in a known manner or entered by a user of the washing machine. According to the invention, it is preferable if a loading quantity of the drum with laundry is determined on the basis of a profile of the pressure signal of a pressure sensor in a wetting phase. For this purpose, in the wetting phase during the rotation of the drum, water is advantageously added thereto and, at a given time t ₁ in the method, the drum is turned and the water is introduced and a change in the pressure signal of the pressure sensor is evaluated to determine the loading quantity.

In the method according to the invention substantially rinse water already used is heated and used to heat the laundry. The heating of the water can be done in different ways. Preferably, the heating in step (d) is carried out using a heater present in the tub for heating a wash liquor. In this case, a minimum amount q _req required for operation of the heater is generally set to water before step (d).

In the inventive method, in step (c) for the case that in step (b) is water collected quantity q _col <q _set, the tub filled with water from the water supply until the water quantity q in the tub q ≥ q _set applies , The water supply includes in particular a water connection fitting for the domestic water network and an electrically controlled two-way valve. Preferably, the water supply is controlled so that for the amount of water q in the tub (1.1 xq _set ) ≥ q ≥ q _set applies.

In a preferred embodiment of the method according to the invention, the temperature T _{w of} the water is measured during step (e) or during step (f) or between step (e) and step (f) in order to determine a sufficient heating of the laundry.

For this purpose, for example, in step (f) with the pump switched off, the drum is operated at the spin speed ω ₂ until a sufficient amount of water q _check is present in the tub for measuring the temperature T _w of the centrifuged water. In general, then, in the case where T _{w is} below a predetermined temperature T _w ^set , then steps (b) to (f) are then carried out again.

If it is not necessary to monitor the heating of the laundry, in a further preferred embodiment, the pump is first switched on in step (f) and then the drum is operated at a spin speed ω ₂ .

The inventive method is not only advantageous for achieving a low residual moisture with further reduced water and / or energy consumption. In particular, it can also be used for disinfecting or destroying germs if laundry is being washed in the washing machine at a relatively low temperature of the washing liquor.

In a preferred embodiment of the method according to the invention, therefore, the steps (a) to (f) are subsequently carried out at a washing phase taking place at a temperature of at most 30 ° C.

In step (d), the level is generally measured. If this does not reach a certain value, the condition q ≥ q _set is usually not fulfilled. The level detection can be done for example by evaluating the hydrostatic pressure in the tub when a pressure sensor is arranged in this. Alternatively or in In addition to this, the electric power of the drive motor can be evaluated in terms of the level of the water, because the electrical power of the drive motor increases with increasing level in the tub.

Preference is therefore given to checking the condition q ≥ q _set in that the amount of water q in the tub is determined by measuring and evaluating the hydrostatic pressure in the tub or by measuring and evaluating the electrical power of the drive motor.

In a particularly preferred embodiment of the process according to the invention, the heated water from step (d) is applied to the laundry by means of a spraying device ("water spray device") whose water outlet opening is directed onto an inner drum wall.

One possibility for this is the water inlet into the drum via a spray device specially designed in the cuff of the washing machine. For directional moistening of the laundry, the water outlet opening of the spraying device can be designed with multiple channels or a fluidically optimized nozzle can be used.

The warm water sprayed onto the laundry, preferably sprayed directly onto the laundry, is preferably accelerated in the process according to the invention to the laundry ring applied to the drum inner wall and forced through the laundry by the centrifugal forces acting on the water. As a result, the laundry can be warmed up particularly well with warm water, so that the retention force for the water in the laundry (also referred to herein as "water absorption capacity") can be efficiently reduced.

It may occur depending on the speed of the drum, the amount of water used and the particular nature of a Wäschepostens and its arrangement on the inner drum shell that the flow of the warm water used in the process according to the invention through the laundry not rectified radially, but partially over forming channels or openings takes place in the laundry. As a result, it may happen that some areas of the laundry are well wetted by the supplied water and thus flowed through or heated, while others are less well.

In a preferred embodiment of the method according to the invention, therefore, step (e) comprises a reversing cycle in which the drum is rotated at a speed below 60 rpm ("revolutions per minute"), preferably below 50 rpm and more preferably below 40 rpm.

1. (a) die Pumpe eingeschaltet und eine im Laugenbehälter befindliche freie Flotte abgepumpt wird;
2. (b) die Pumpe anschließend abgeschaltet wird und bei abgeschalteter Pumpe die Trommel mit einer Schleuderdrehzahl ω₁ betrieben wird, um den Feuchtigkeitsgehalt der feuchten Wäsche aus Schritt (a) zu verringern und das dabei ausgetriebene Wasser im Laugenbehälter aufzufangen, so dass für die Wassermenge q im Laugenbehälter q = q_col gilt;
3. (c) für den Fall, dass die im Schritt (b) aufgefangene Wassermenge q_col < q_set ist, der Laugenbehälter mit Wasser aus der Wasserversorgung aufgefüllt wird, bis für die Wassermenge q im Laugenbehälter q ≥ q_set gilt;
4. (d) die Wassermenge q im Laugenbehälter auf eine vorgegebene Temperatur T_set erhitzt wird;
5. (e) das erhitzte Wasser aus Schritt (d) in der Wäsche verteilt wird; und
6. (f) die Trommel mit einer Schleuderdrehzahl ω₂ betrieben wird, um in der Wäsche verteiltes erhitztes Wasser aus Schritt (e) aus der Wäsche zu treiben und abzupumpen.

The invention also relates to a washing machine with a control device for controlling a program sequence, a drum rotatably mounted in a tub, a heater, a pump and a drive motor for the drum, wherein the control device is adapted to carry out a method for washing laundry, wherein following a washing phase in a rinsing phase with one or more rinsing steps at least in the last rinsing step after the addition of the last rinse water portion into the tub and the rinsing of the laundry

1. (a) the pump is switched on and a free liquor contained in the tub is pumped out;
2. (b) the pump is then switched off and when the pump is the drum at a spin speed ω ₁ is operated to reduce the moisture content of the wet wash of step (a) to reduce and absorb the thereby expelled water in the tub, such that for the water quantity q in the tub q = q _col applies;
3. (c) in the event that the quantity of water collected in step (b) is q _col <q _set , the tub is filled with water from the water supply until q ≥ q _set applies to the amount of water q in the tub;
4. (D) the amount of water q is heated in the tub to a predetermined temperature T _set ;
5. (e) distributing the heated water from step (d) in the laundry; and
6. (F) the drum is operated at a spin speed ω ₂ , to drive in the laundry distributed heated water from step (e) from the laundry and pump.

In a preferred embodiment, the washing machine has a spraying device with which the heated water from step (d) is applied to the laundry.

The invention has the advantage that the reduction of the residual moisture of laundry after a washing process and a subsequent spin in a washing machine can be achieved in an economical manner. In addition to a saving of water and a saving of energy is possible. In addition, the invention allows that at a Lower mechanical load, a lower residual moisture, ie Schleuderrestfeuchte can be achieved. Finally, the invention makes it possible to kill germs even when washing at low temperature via a so-called rinsing spinner block at elevated temperature. In such a case can also be spoken by a Hygienespülblock.

The invention will be described below with reference to the FIG. 1 illustrated in more detail.

Fig. 1 is a schematic representation of a washing machine in which a method according to the invention can be carried out. Other embodiments are conceivable. The washing machine in Fig. 1 has a tub 1, in which a drum 2 is rotatably mounted and can be operated by a drive motor 14. The axis of rotation 3 of the drum 2 is directed from the horizontal by a small angle (for example, 13 °) forward and upwards, so that one has easier access and insight into the interior of the drum 2. By this arrangement, in conjunction with Wäschemitnehmern 4 and 5 Schöpfeinrichtungen for the wash liquor or hot water 6 on the inner surface of the drum shell also an intensification of the flooding of the laundry 7 with wash liquor or warm water 6 is achieved. The scooping devices 5 of in Fig. 1 shown washing machine are designed so that they can optimally draw water at the right rotation of drum 2 shown here by the arrow 17.

The washing machine also has a liquor inlet system comprising a water connection fitting for the domestic water network 8, an electrically controllable two-way valve 9 and a supply line 10 to the tub 1, which may optionally also be guided via a Waschmitteleinspüleinrichtung ("Einspülschale") 11, from which the feed water In a washing phase can carry detergent portions in the tub 1. In addition, in the tub 1, a heater 13. The two-way valve 9 as well as the heater 13 can be controlled by a control device 12 in response to a flowchart, the to a time program and / or the achievement of certain measurements of parameters such as liquor level, liquor temperature , Speed of the laundry drum, etc. may be bound within the washing machine. In particular, the control device 12 is set up to carry out a method according to the invention with the steps (a) to (f). For example, in step (c), the controller may control the replenishment of the water until the condition q ≥ q _{set is} satisfied. After a suitable evaluation, the control device 12 can suitably control, for example, the heater, the drive motor and the pump.

In addition, in one embodiment of the method according to the invention, the loading amount with laundry can be taken into account, for example by resorting to a relationship between loading amount and water quantity stored in the control device 12 in relation to a total amount of water to be used in step (d).

At the in Fig. 1 In the embodiment shown, the tub 1 is equipped with a water spray device 18, which is designed so that the water heated in step (d) can be sprayed with it on the laundry 7, which is located on an inner drum shell 19 of the drum 2. The warm water exits from a water outlet opening 20. The water spray device 18 can be supplied using an electrically controllable three-way valve 21, which can be switched so that a liquid present in the tub 1 can be conveyed either to the water spray device 18 or to a waste water outlet 22.

In Fig. 1 15 means a pressure sensor for the measurement of the hydrostatic pressure p in the tub 1. The hydrostatic pressure p results from the level of the water. The signals from drive motor 14, pressure sensor 15 and a temperature sensor 23 are supplied to the control device 12. In particular, it can be determined with the temperature sensor 23 whether the heating of the laundry 7 is sufficient or steps (b) to (f) of the method according to the invention have to be carried out again.

After the heated water in the laundry 7 has been distributed using the water spray device 18 and performing a reversing cycle in which the drum is rotated at a speed below 60 rpm, preferably below 50 and more preferably below 40 rpm last spin step to be pumped off with the pump 16 turned on. As a result, laundry results in a reduced residual moisture.

LIST OF REFERENCE NUMBERS

1

tub

2

drum

3

axis of rotation

4

laundry agitator

5

scoop

6

(warm water; free fleet

7

Laundry

8th

Water connection fitting for the domestic water network

9

electrically controllable two-way valve

10

Supply line to the tub

11

Washing agent

12

control device

13

heater

14

drive motor

15

pressure sensor

16

pump

17

optimal direction of rotation for the scooping device

18

Water spraying

19

inner drum shell

20

Water outlet opening

21

electrically controllable three-way valve

22

wastewater discharge

23

temperature sensor

Claims (14)

1. Method for rinsing laundry (7) in a washing machine having a control device (12) for controlling a program sequence, a drum (2), which is rotatably mounted in a liquor container (1), a heating device (13), a pump (16) and a drive motor (14) for the drum (2), according to which method in a rinsing phase having one or more rinsing steps following a wash phase, at least in the last rinsing step after the last portion of rinsing water is added to the liquor container (1) and the laundry (7) is rinsed through,

   (a) the pump (16) is switched on and a free detergent solution (6) situated in the liquor container (1) is pumped out;

   (b) the pump (16) is then switched off, and the drum (2) is operated at a spin speed ω1 with the pump (16) switched off, in order to reduce the moisture content of the damp laundry (7) from step (a) and to collect the water driven out in the process in the liquor container (1), such that for the quantity of water q in the liquor container, q = q_col ;

   (c) if the quantity of water collected in step (b) is q_col <q_set , the liquor container (1) is filled up with water from the water supply (8, 9) until q ≥ q_set for the quantity of water q in the liquor container (1), wherein q_set is a predetermined quantity of water;

   (d) wherein the condition q ≥ q_set is monitored such that the quantity of water q in the liquor container (1) is determined by measuring and evaluating a hydrostatic pressure in the liquor container (1) and/or by measuring and evaluating an electrical output of the drive motor (14), wherein the quantity of water q in the liquor container (1) is heated to a predetermined temperature T_set ;

   (e) the heated water from step (d) is distributed in the laundry (7); and

   (f) the drum (2) is operated at a spin speed ω ₂ in order to drive heated water distributed in the laundry (7) from step (e) out of the laundry (7) and pump it away.
2. Method according to claim 1, characterised in that the pumping-away is performed in step (a) until a delivery rate of the pump (16) is reduced to 10% of its initial value p_init .
3. Method according to claim 1 or 2, characterised in that the pumping-away is performed in step (a) until the pump (16) identifies the start of the delivery of a gas/air mixture.
4. Method according to one of claims 1 to 3, characterised in that when the pump (16) is switched on (a1), a gentle spin with the drum (2) is performed, wherein in step (a1) the drum (2) is operated for a period of at most one minute at a number of revolutions ω of at most 500 rpm.
5. Method according to one of claims 1 to 4, characterised in that the predetermined temperature T_set lies in the range of 40°C to 95°C.
6. Method according to one of claims 1 to 5, characterised in that a relationship between the predetermined quantity of water q_set and a load quantity w_w is stored in the control device (12), wherein the quantity of water q_set is lower for smaller load quantities w_w .
7. Method according to one of claims 1 to 6, characterised in that the heating in step (d) takes place using the heating device (13) present in the liquor container (1) for heating a wash liquor.
8. Method according to claim 7, characterised in that prior to step (d), a minimum quantity q_req of water required to operate the heating device (13) is set.
9. Method according to one of claims 1 to 8, characterised in that the temperature T_w of the water is measured during step (e) or during step (f) or between step (e) and step (f) in order to define an adequate heating-up of the laundry.
10. Method according to claim 9, characterised in that in step (f) when the pump (16) is switched off, the drum (2) is operated with a spin speed ω ₂, until a quantity of water q_check which is adequate to measure the temperature T_w of the spun-off water is present in the liquor container (1).
11. Method according to claim 10, characterised in that if T_w is below a predetermined temperature $T_w^{\mathit{set}},$

    

    steps (b) to (f) are performed again.
12. Method according to one of claims 1 to 8, characterised in that in step (f) the pump (16) is firstly switched on and the drum (2) is then operated with a spin speed ω ₂.
13. Method according to one of claims 1 to 12, characterised in that the steps (a) to (f) are then performed following a wash phase taking place at a temperature of at most 30°C.
14. Washing machine having a control device (12) for controlling a program sequence, a drum (2) which is rotatably mounted in a liquor container (1), a heating device (13), a pump (16) and a drive motor (14) for the drum (2), characterised in that the control device (12) is set up to perform a method for rinsing laundry (7), according to which method, in a rinsing phase having one or more rinsing steps following a washing phase, at least in the last rinsing step after the last portion of rinsing water is added to the liquor container (1) and the laundry (7) is rinsed through,

    (a) the pump (16) is switched on and a free detergent solution (6) situated in the liquor container (1) is pumped out;

    (b) the pump (16) is then switched off, and the drum (2) is operated at a spin speed ω ₁ with the pump (16) switched off, in order to reduce the moisture content of the damp laundry (7) from step (a) and to collect the water driven out in the process in the liquor container (1), such that for the quantity of water q in the liquor container,
    q = q_col ;

    (c) if the quantity of water collected in step (b) is q_col <c_set , the liquor container (1) is filled up with water from the water supply (8, 9) until q ≥ q_set for the quantity of water q in the liquor container (1), wherein q_set is a predetermined quantity of water;

    (d) wherein the condition q ≥ q_set is monitored such that the quantity of water q in the liquor container (1) is determined by measuring and evaluating a hydrostatic pressure in the liquor container (1) and/or by measuring and evaluating an electrical output of the drive motor (14), wherein the quantity of water q in the liquor container (1) is heated to a predetermined temperature T_set ;

    (e) the heated water from step (d) is distributed in the laundry (7); and

    (f) the drum (2) is operated at a spin speed ω ₂ in order to drive heated water distributed in the laundry (7) from step (e) out of the laundry (7) and pump it away.

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