WO2014191248A1 - Method for operating a washing machine achieving an improved residual moisture content of the laundry, and washing machine suitable therefor - Google Patents

Abstract

The invention relates to a 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 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 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); (d) the quantity of water q in the liquor container (1) is heated to a predefined 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 ω₂ in order to drive heated water distributed in the laundry (7) from step (e) out of the laundry (7) and pump it away. The invention further relates to a washing machine suitable for carrying out the method.

Description

 Method for operating a washing machine with an improved residual moisture content of the laundry and suitable washing machine for this purpose

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.

A washing program in a washing machine with a drum rotatably mounted in a tub generally has a rinsing phase with several spinning steps 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, does not have to be taken out dripping wet. In particular, it is desirable that the residual moisture still present in the laundry after the spin phase, which is often referred to as "slug residual moisture", is as low as possible This is generally achieved by a good separation of the water during spinning at a high rotational 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" becomes. 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.

EP 2 390 397 A1 discloses 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 washing cycle is carried out using heated water in order to raise the temperature inside 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.

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. 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

 (a) the pump is switched on and a free liquor contained in the tub is pumped out;

(b) the pump is then shut down and, with the pump off, the drum is operated at a spinning speed ooi to reduce the moisture content of the wet laundry from step (a) and trap the water thus expelled in the tub so that q for the water q Liquids container q = q _C0 | applies;

(c) in the event that the amount of water collected in step (b) is q _CO i <q _se t, the tub is filled with water from the water supply until q> q _set applies to the amount of water q in the tub;

(D) the amount of water q is heated in the tub to a predetermined temperature T _set ;

(e) distributing the heated water from step (d) in the laundry; and

(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. 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 _in it.

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 remaining 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) Therefore, in step (a1), in step (a1), the drum (2) is allowed to rotate for at most one minute with a number of revolutions ω of at most 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, whereby the predetermined temperature T _set is generally in the range of 40 ° C. to 95 ° C. Depending on the type and quantity of Laundry, the predetermined temperature T _set in this area can be suitably selected gsform the method is therefore in the control device of the washing machine used a relationship between the predetermined amount of water q _set and a loading amount w _w deposited. 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 and, at a given time t.sub.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 for determining 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) quantity of water collected q _CO i <q _se t is, 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 _se t 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 _che c _k is present in the tub for measuring the temperature T _w of the centrifugalized 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 method 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 is directed onto an inner drum wall, one possibility being the water inlet into the drum For the purpose of moistening 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 method according to the invention is preferably accelerated on the laundry ring applied to the inner wall of the drum and driven through the laundry by the centrifugal forces acting on the water, thereby making it possible to warm the laundry particularly well with warm water n, so that the retention force for the water in the laundry (herein also referred to 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.

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

(a) the pump is switched on and a free liquor contained in the tub is pumped out;

(B) the pump is then switched off and the pump is switched off with the drum at a spin speed ω-ι to reduce the moisture content of the wet laundry from step (a) and thereby catch the expelled water in the tub, so that for the amount of water q in the tub q = q _CO i;

(c) in the event that the amount of water collected in step (b) is q _CO i <q _se t, the tub is filled with water from the water supply until q> q _set applies to the amount of water q in the tub;

(D) the amount of water q is heated in the tub to a predetermined temperature T _set ;

(e) distributing the heated water from step (d) in the laundry; and

(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 is illustrated in more detail below with reference to FIG.

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 comprises 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 (e.g., 13 °) forwardly upwards, so as to provide 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 the washing machine shown in Fig. 1 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") 1 1, from the In addition, in the tub 1, a heating device 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 time program and / or can be bound to the achievement of certain measured values of parameters such as liquor level, liquor temperature, speed of the laundry drum, etc. 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).

In the embodiment shown in Fig. 1, the tub 1 is equipped with a Wassersprühvorrichtung 18 which is designed so that with her in step (d) heated water targeted to the laundry 7, located on an inner drum shell 19 of drum. 2 can be sprayed. 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 is a pressure sensor for measuring 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

I lye container

2 drum

 3 rotation axis

 4 laundry hamper

 5 scooping device

 6 (warm) water; free fleet

7 laundry

 8 Water connection fitting for the domestic water network

9 electrically controllable two-way valve

 10 Supply line to the tub

 I I detergent dispenser

12 control device

 13 heating device

 14 drive motor

 15 pressure sensor

 16 pump

17 optimal direction of rotation for the scooping device

18 water spray device

 19 inner drum casing

 20 water outlet opening

 21 electrically controllable three-way valve

22 wastewater discharge

 23 temperature sensor

Claims

Patent claims Method for rinsing laundry (7) in a washing machine with a control device (12) for controlling a program sequence, a drum (2) rotatably mounted in a tub (1), a heating device (13), a pump (16) and a drive motor (14) for the drum (2), wherein following a washing phase in a rinsing phase with one or more rinsing steps at least in the last rinsing step after adding the last portion of rinsing water into the tub (1) and rinsing the laundry (7) (a) the pump (16) is switched on and a free liquor (6) located in the tub (1) is pumped out; (b) the pump (16) is then switched off and when the pump (16) is switched off, the drum (2) is operated at a spin speed ω-ι in order to reduce the moisture content of the damp laundry (7) from step (a) and that to collect the water expelled in the tub (1), so that for the amount of water q in the tub q = q _C0 | applies; (c) in the event that the amount of water q _CO i < q _se t collected in step (b), the tub (1) is filled with water from the water supply (8,9) until the amount of water q in the tub (1 ) q > q _set holds; (d) the amount of water q in the tub (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 out. Method according to claim 1, characterized in that the pumping out in step (a) is carried out until a delivery rate of the pump (16) has fallen to 10% of its initial value ρ _Μ . Method according to claim 1 or 2, characterized in that the pumping out in step (a) is carried out until the pump (16) detects the start of delivery of a gas/air mixture. 4. The method according to any one of claims 1 to 3, characterized in that when the pump (16) (a1) is switched on, a slight spin is carried out with the drum (2). 5 5. The method according to claim 4, characterized in that 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 revolutions / min. 6. The method according to any one of claims 1 to 5, characterized in that the predetermined temperature T _set is in the range from 40 ° C to 95 ° C. 7. The method according to one of claims 1 to 6, characterized in that a relationship between the predetermined amount of water q _set and a load amount w _w is stored in the control device (12), whereby the 15 amount of water q _set is lower for lower load quantities w _w . 8. The method according to any one of claims 1 to 7, characterized in that the heating in step (d) takes place using the heating device (13) present in the tub (1) for heating a washing solution. 20 9. The method according to claim 8, characterized in that before step (d) a minimum amount q _req of water required to operate the heating device (13) is set. 25 10. Method according to one of claims 1 to 9, characterized in that during Step (e) or during step (f) or between step (e) and step (f) the temperature T _w of the water is measured to determine that the laundry has warmed up sufficiently. 30 1 1 . Method according to claim 10, characterized in that in step (f) with the pump (16) switched off, the drum (2) is operated at the spin speed ω ₂ until there is one in the tub (1) for measuring the temperature T _w of the spun water there is a sufficient amount of water q _che c _k . 12. The method according to claim 1 1, characterized in that in the event that T _w is below a predetermined temperature T _w ^set , steps (b) to (f) are carried out again. 13. The method according to one of claims 1 to 9, characterized in that in step (f) the pump (16) is first switched on and then the drum (2) is operated at a spin speed ω ₂ . 14. The method according to any one of claims 1 to 13, characterized in that steps (a) to (f) are carried out subsequently to a washing phase which takes place at a temperature of a maximum of 30 ° C. 15. Washing machine with a control device (12) for controlling a program sequence, a drum (2) rotatably mounted in a tub (1), a heating device (13), a pump (16) and a drive motor (14) for the Drum (2), characterized in that the control device (12) is set up to carry out a method for rinsing laundry (7), in which, following a washing phase, in a rinsing phase with one or more rinsing steps at least in the last rinsing step after adding the last portion of rinse water into the tub (1) and rinse the laundry (7) (a) the pump (16) is switched on and a free liquor (6) located in the tub (1) is pumped out; (b) the pump (16) is then switched off and when the pump (16) is switched off, the drum (2) is operated at a spin speed ooi in order to reduce the moisture content of the damp laundry (7) from step (a) and the expelled Collect water in the tub (1) so that for the amount of water q in the tub, q = q _CO i; (c) in the event that the amount of water q _CO i < q _se t collected in step (b), the tub (1) is filled with water from the water supply (8,9) until the amount of water q in the tub (1 ) q > q _set holds; (d) the amount of water q in the tub (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 out.