EP3091117B1 - Washer dryer and method for operating a washer dryer - Google Patents

Description

The invention relates to a washer-dryer, that is to say a domestic appliance which is capable of both washing and drying laundry. As an alternative to an arrangement of a washing machine and a separate tumble dryer, the washer dryer primarily saves space - it only needs to be purchased and set up a device.

As is customary in a washing machine, a washer-dryer has a tub and a laundry drum rotatably arranged in the tub to hold laundry. In addition, as is usual with a tumble dryer, a heating element, a fan and a condenser are provided, which together with the tub provide a circuit which is traversed by a process air in a drying process. This prior art is based on the Fig. 1 explained.

Another drying concept provides that adsorbents are used for drying in household appliances. An example of this shows EP 2 315 547 B1 , From which results in a dishwasher in which a zeolite-filled sorption is operated as a drying device. An application of drying by means of adsorption in the area of the washer dryer is described in EP 2 439 329 B1 and in DE 10 2007 031 481 A1 disclosed. The DE10 2012 221830 A1 discloses a washer dryer or a method for operating a washer-dryer according to the preamble of each of claims 1 and 8. The problem with the use of an adsorbent-filled adsorption module for drying laundry is that a large amount of moisture has to be removed from the laundry. To dry the entire laundry exclusively by means of adsorption, the adsorption module would have to be dimensioned correspondingly large, which would lead to installation space problems in the domestic appliance.

The invention thus presents the problem of providing a washer-dryer and a method for its operation in which the size of the adsorption module or the amount of adsorbent is optimized.

According to the invention, this problem is solved by a washer-dryer with the features of patent claim 1 and by a method having the features of patent claim 8. Advantageous embodiments and modifications of the invention will become apparent from the dependent claims.

The invention is based on the consideration of designing an adsorption module in such a way that the energy consumption of an overall process of washing phase and drying phase in the washer-dryer is minimized. In this case, the adsorption module is not designed to receive all the moisture contained in the laundry during the drying phase. Instead, it is about bringing in the excess energy arising during the desorption process as completely as possible in the subsequent washing process. Depending on the selected degree of drying and the moisture content of the laundry, however, the adsorption module designed in this way may well be sufficient to operate the entire drying phase exclusively by means of adsorption. The washer-dryer has a control device which is designed to carry out the treatment method according to the invention.

The adsorption module may be an open adsorption system in direct communication with the atmosphere. Here, the adsorption and the desorption occur at ambient pressure. Alternatively, it may be a closed adsorption system, ie a system sealed from the ambient air. With a closed adsorption system, the working pressure can be freely selected.

If it is initially assumed that a partially or already completely discharged adsorption module, ie an adsorption module in which the adsorbent contained therein is essentially dry, then moist process air is blown out of the tub into the adsorption module during the drying phase by the fan. The moisture from the process air is adsorbed by the adsorbent. The adsorption is an exothermic process, so that the heat energy released due to the adsorption process heats the process air. The dry due to the flow through the adsorption hot process air is passed by means of the blower in the tub, where it absorbs moisture from there arranged in the laundry drum laundry and so dry the laundry. The now again moist process air is then passed through the adsorption module again in the sense of a cycle in order to continue loading the adsorbent.

The drying process may continue to operate until the adsorbent is fully loaded, that is, until the adsorbent is unable to absorb additional moisture at a given process pressure. This is usually carried out at a loading of the adsorbent between 20% and 40%, depending on the adsorbent. If the laundry is then not sufficiently dry, drying the clothes by means of a conventional drying process can continue.

Here, as explained in the introduction, a capacitor can be used. In addition, the use of a heat pump can be beneficial.

Preferably, however, the adsorption module in the drying phase is operated simultaneously with the condenser and optionally with the heat pump. This has the advantage that the drying process can run faster. In this case, the majority of moisture is removed from the process air passing out of the tub by means of the condenser, and the adsorption module serves to remove the residual moisture from the process air which emerges from the condenser. In addition, the process may be tuned so that the adsorbent in the adsorption module is fully loaded only at the end of the drying phase or even at the end of two consecutive drying phases.

Alternatively, the adsorption module can also be operated temporarily or at intervals in the drying phase. In particular, a boost mode can be provided, in which the adsorption module is switched on after half or towards the end of a drying phase in order to accelerate the drying process abruptly.

Due to the usually smaller capacity of the washing drum of a washer dryer compared to a stand-alone dryer, a wash load of laundry after the washing phase is usually distributed over two drying processes. For example, following a wash at a standard load of 5.5 kg of laundry, usually two drying phases are performed at a load of about 2.75 kg each. This is the reason why it can be advantageous if the adsorption module is completely laden with moisture only after the second drying phase. The advantage is then that the adsorption module can be active during both drying phases in order to support the drying process.

If it is now assumed that a partially or already fully loaded adsorption module, ie an adsorption module in which the adsorbent is loaded to saturation with adsorbed moisture, then the moisture is removed from the adsorbent and in the tub in a subsequent washing phase in a desorption process directed. In the tub is now usually other laundry than during the previous drying phase. In order to perform the desorption process efficiently, the process air fed into the adsorption module must have a certain minimum temperature, namely an adsorption-dependent desorption temperature. This desorption temperature is much higher in conventional adsorbents than the temperature required for washing. The moist process air emerging from the adsorption module is therefore always warmer than the laundry in the tub, so that the moisture condenses on the laundry. by virtue of condensation heat is released in this condensation process so that the laundry is heated at the same time and brought to the optimum washing temperature required for the selected washing process.

During the washing phase, heat of condensation is given off to the laundry in this way. The overall heat of condensation that can be delivered to the laundry in this way is reached when the adsorption module has moved from a fully loaded state back into the completely discharged state, ie when the adsorbent in the adsorption module is again substantially dry. According to the invention, the adsorption module contains maximally so much adsorbent that this total heat of condensation does not exceed the washing energy required for a normal washing process by more than 20%, 10% or 5%. Preferably, the Gesamtkondensationswärme deliverable to the laundry does not exceed the washing energy required for a normal washing process. This means that it is possible by condensing the maximum moisture absorbable in the absorbent only as much heat of condensation to give the laundry, as needed for a normal washing process, or just a maximum of up to 20%, 10% or 5% more. This has the advantage that the adsorption module only has to be designed so large that there is an efficient use of energy. In this way it can be avoided that the adsorption module is designed to be unnecessarily large and thus requires unnecessary space in the washer-dryer.

In a preferred embodiment, it is provided that the total adsorbed by the adsorbent total moisture in completely laden with moisture adsorbent loading of the adsorbent between 20% and 45%, preferably between 25% and 35% or between 30% and 40%. In this state, also referred to as the state of maximum loading, the adsorbate, that is to say the adsorbed moisture, has the same molar free enthalpy as the free liquid, that is to say the not yet adsorptive, which surrounds the adsorbent. The loading is defined as the mass ratio between the adsorbate, ie the adsorbed moisture, and the adsorbent or adsorbent. For zeolite, the maximum load is about 30%, while for silica gel it is about 35-40%.

In an advantageous development, it is provided that the normal washing process corresponds to a standard washing cycle at a washing temperature of 60 ° C. and a laundry load of 5.5 kg of laundry. When the washer-dryer has a larger capacity washing drum, it is advantageous if the normal washing operation is equivalent to a standard one-load laundry load. For example, the normal washing process can assist in a standard wash cycle a washing temperature of 60 ° C and a laundry load of 6 kg, 6.5 kg, 7 kg or 8 kg of laundry.

In a preferred embodiment, it is provided that the total heat of condensation which can be delivered to the laundry is between 500 watt hours and 900 watt hours, preferably between 600 watt hours and 850 watt hours, more preferably between 700 watt hours and 800 watt hours.

According to a preferred embodiment it is provided that the adsorption module contains between 2kg and 7kg adsorbent, preferably between 2.5kg and 4.5kg or between 4.5kg and 6.5kg, more preferably between 3kg and 4kg or between 5kg and 6kg. When using zeolite, the adsorption module preferably contains between 3kg and 4kg zeolite, more preferably about 3.55kg, and when using silica gel preferably between 5kg and 6kg silica gel, more preferably about 5.85kg.

In an expedient embodiment, it is provided that the adsorption module contains as adsorbent a silica gel, also called silica gel, and / or a zeolite. In particular, the silica gel 123, 125 and / or 127 and the zeolite 13X are advantageous here. Salts are preferably incorporated into the silica gel, for example calcium chloride hexahydrate, in order to obtain a so-called selective water sorbent (SWS) as the adsorbent. In any case, the adsorbent may be in the form of a bed in a fixed bed reactor.

Preferably, a lye container inlet heating element, which is arranged in a lye container inlet line to heat the process air immediately before entering the tub, and / or an adsorption module inlet heating element is provided, which is arranged in a Adsorptionsmodulzulaufleitung to the process air immediately before entry to heat in the adsorption module. In addition or as an alternative to the adsorption module feed heating element, it is possible to provide an adsorption module heating element which is set up to bring the adsorption module to the desorption temperature necessary for the desorption process.

The adsorption module is optionally arranged together with the adsorption module inlet heating element between the fan and the tub or the tub inlet heating element, preferably so that the process air passing out of the tub flows through first the condenser, then the fan and then the adsorption module and finally returned to the tub. In this way, existing washer-dryers can preferably also be retrofitted with an adsorption module.

Fig. 1

eine schematische Darstellung der Komponenten eines konventionellen Waschtrockners und den Ablauf beim konventionellen Trocknungsprozess; und

Fig. 2

eine schematische Darstellung eines erfindungsgemäßen Waschtrockners gemäß einer bevorzugten Ausführungsform.

An embodiment of the invention is shown purely schematically in the drawings and will be described in more detail below. It shows

Fig. 1

a schematic representation of the components of a conventional washer dryer and the process in the conventional drying process; and

Fig. 2

a schematic representation of a washing dryer according to the invention according to a preferred embodiment.

The course of a conventional drying process in a washer-dryer according to the prior art will be described with reference to the schematic representation in FIG Fig. 1 explained. Here, a cycle process is illustrated by means of the broad arrows which schematically represent the flow of a process air 7 between main components of the washer dryer. In a tub 1 is still wet laundry in a washing drum 11. First, drier process air 7 flows into the tub 1 and removes moisture from the laundry. The cooled and moist process air 7 due to this process flows to the condenser 3, where it continues to cool and the moisture partially condenses out. At the outlet of the condenser 3, the now much cooler process air 7 has a humidity of almost 100%. The process air 7 is then passed to a heating element 5, which heats the process air 7. This reduces the relative humidity of the process air 7. By means of a blower 6, the warm dry process air 7 is again supplied to the tub 1.

The resulting cycle is maintained until the laundry in the tub 1 has reached the desired degree of dryness and the drying process is completed. It may also be a heat pump system (not shown) may be used, which is a combination of an evaporator and a condenser. Then it is spoken by a heat pump condenser dryer or by a condensation dryer, which works on the principle of the heat pump. Also in all embodiments of the invention described above or below, instead of the condenser 3, such a heat pump system can be used.

In the Fig. 2 an embodiment of a washer dryer according to the invention is shown schematically with reference to a flow chart. Here, the circuit comprises the tub 1, in which the washing drum 11 is rotatably mounted, the condenser 3, the blower 6 and an adsorption module 2, which is filled with an adsorbent. The components within the dashed frame 71 are those in the conventional washer-dryer Fig. 1 already existing components. From the tub 1 a capacitor feed line 43 leads to the capacitor 3. A Lye container inlet line 41 leads the process air to the tub 1 and a Adsorptionsmodulzulaufleitung 42 to the adsorption tank 2. These lines 41, 42, 43 may be partially to channels, pipes or hoses. However, the term line may also simply mean any kind of structure which causes the process air 7 to be directed along a desired path to the respective component 1, 2, 3 of the washer dryer.

In addition, a tub inlet heating element 51 and an adsorption module inlet heating element 52 are provided. The suds container inlet heating element 51 serves to heat the process air 7 emerging from the adsorption module 2 before it flows into the suds container 1. This is necessary in a drying phase, when the temperature increase achieved due to the adsorbent used is not sufficient to dry the laundry efficiently. In the drying phase, therefore, the fan 6, the condenser 3, the adsorption module 2 and optionally the suds container inlet heating element 51 are active. The initially moist process air 7 is passed through the condenser feed line 43 to the condenser 3, where it cools as in a conventional dryer. Although much of the moisture in the process air 7 condenses in the condenser 3, but due to the reduced temperature of the process air 7, its relative humidity increases to about 100%. This cool moist air is conducted by means of the blower 6 through the Adsorptionsmodulzulaufleitung 42 in the adsorption 2.

In the adsorption module 2, the residual moisture from the process air 7 is adsorbed on the adsorbent and the process air 7 undergoes a temperature elevation. If the temperature of the process air 7 after the temperature stroke is sufficient to effectively remove moisture from the laundry in the tub 1, then the warm air that is now dry due to the adsorption process is passed through the liquor container supply line 51 into the tub 1, without being further heated. Otherwise, the process air 7 is heated by means of the liquor container inlet heating element 51 to the necessary temperature and enters the tub 1.

After completion of the drying phase, the dry laundry is usually removed by the user from the washing drum 11 and placed either immediately after a period of time, for example after a few hours, days or even weeks, a new load of laundry laundry in the washing drum 11. Then a washing phase is initiated. During the washing phase, preferably at the beginning of the washing phase, in a commercial washer-dryer according to Fig. 1 the laundry is heated by means of a arranged below the tub heating element and brought to the desired or required washing temperature. In the present case, this is done instead by means of the emerging from the adsorption 2 process air 7. Die Process air 7 was first heated to the required desorption temperature by means of the adsorption module inlet heating element 42. This is about 150 ° C for silica gel and about 300 ° C for zeolite.

The hot dry process air 7 then flows through the adsorption module 2 and absorbs the moisture stored in the adsorbent in a desorption process. As a result, the process air 7 is cooled slightly and at the same time moister. The moist process air 7 from the adsorption module 2 is then passed through the tub container feed line 41 into the tub 1. There condenses the moisture from the process air to the laundry, on the walls of the tub 1 and the washing drum 11. Due to this condensation process condensation heat is released, which heats the laundry. The desorption process ends when the adsorbent is completely dry, that is, when the adsorption module 2 is completely regenerated, or when the laundry has reached the desired wash temperature, so that the washing process can begin. If the adsorbent still contains moisture, the desorption process can be repeated within the wash phase to warm the wash.

According to the invention, the energy which can be stored on the laundry by means of condensation, which is the maximum storage capacity in the adsorption module 1, is sufficient to provide the energy required in the washing process. The energy required is preferably not exceeded by the total heat of condensation, by 5%, by 10% or by 20%. The energy required for the washing process preferably consists of the heat energy, which is necessary for heating the laundry to the desired washing temperature.

LIST OF REFERENCE NUMBERS

1

tub

11

washing drum

2

adsorption module

3

capacitor

41

Tub supply line

42

Adsorptionsmodulzulaufleitung

43

Condenser inlet line

5

heating element

51

Tub inlet heater

52

Adsorptionsmodulzulauf heater

6

fan

7

process air

71

frame

Claims (8)

1. Washer-dryer comprising a suds container (1) in which a laundry drum (11) for receiving laundry is rotatably mounted, an adsorption module (2) which contains an adsorbent for receiving moisture, a fan (6) which is designed to exchange process air between the suds container (1) and the adsorption module (2), and a control device which is designed to convey, by means of the fan (6), dry process air from the adsorption module (2) into the suds container (1) during a drying phase in such a way that moisture from the laundry is emitted to the process air, and to convey, by means of the fan (6), moist process air from the adsorption module (2) into the suds container (1) during a washing phase in such a way that moisture from the process air condenses on the laundry and the laundry is heated by means of condensation heat released in this condensing process, characterised in that the adsorption module (2) contains at most so much adsorbent that an overall condensation heat emitted to the laundry exceeds the washing energy required for a normal washing process by no more than 20%, 10% or 5%, the overall condensation heat then being emitted to the laundry when, in the case of the adsorbent being fully loaded with moisture, the overall moisture adsorbed by the adsorbent is completely desorbed from the adsorbent and is condensed on the laundry.
2. Washer-dryer according to claim 1, characterised in that the overall moisture that can be adsorbed by the adsorbent when the adsorbent is fully loaded with moisture corresponds to the adsorbent being loaded by between 20% and 45%, preferably between 25% and 35% or between 30% and 40%.
3. Washer-dryer according to either claim 1 or claim 2, characterised in that the normal washing process corresponds to a standard washing cycle at a washing temperature of 60°C and a laundry load of 5.5 kg, 7 kg or 8 kg of laundry.
4. Washer-dryer according to any of the preceding claims, characterised in that the overall condensation heat that can be emitted to the laundry is between 500 watt-hours and 900 watt-hours, preferably between 600 watt-hours and 850 watt-hours, more preferably between 700 watt-hours and 800 watt-hours.
5. Washer-dryer according to any of the preceding claims, characterised in that the adsorption module (2) contains between 2 kg and 7 kg adsorbent,
   preferably between 2.5 kg and 4.5 kg or between 4.5 kg and 6.5 kg, more preferably between 3 kg and 4 kg or between 5 kg and 6 kg.
6. Washer-dryer according to any of the preceding claims, characterised in that the adsorption module (2) contains a silica gel and/or a zeolite as the adsorbent.
7. Washer-dryer according to any of the preceding claims, characterised by a suds container inlet heating element (51), which is arranged in a suds container inlet line (41), for heating the process air directly before it enters the suds container (1), and/or by an adsorption module inlet heating element (52), which is arranged in an adsorption module inlet line (42), for heating the process air directly before it enters the adsorption module (2).
8. Method for operating a washer-dryer comprising a suds container (1) in which a laundry drum (11) for receiving laundry is rotatably mounted, an adsorption module (2) which contains an adsorbent for receiving moisture, and a fan (6) which is designed to exchange process air between the suds container (1) and the adsorption module (2), the method being designed to convey, by means of the fan (6), dry process air from the adsorption module (2) into the suds container (1) during a drying phase in such a way that moisture from the laundry is emitted to the process air, and to convey, by means of the fan (6), moist process air from the adsorption module (2) into the suds container (1) during a washing phase in such a way that moisture from the process air condenses on the laundry and the laundry is heated by means of condensation heat released in this condensing process, characterised in that, during the washing phase, an overall condensation heat emitted to the laundry exceeds the washing energy required for a normal washing process by no more than 20%, 10% or 5%, the overall condensation heat then being emitted to the laundry when, in the case of the adsorbent being fully loaded with moisture, the overall moisture adsorbed by the adsorbent is completely desorbed out of the adsorbent and is condensed on the laundry.

Images