WO2012028458A1

WO2012028458A1 - Method for cleaning an air path in a washer/dryer, and washer/dryer suitable for this purpose

Info

Publication number: WO2012028458A1
Application number: PCT/EP2011/064147
Authority: WO
Inventors: Bernhard Heym; Harald MOSCHÜTZ; Burghardt Paul; Wolfgang Platte
Original assignee: BSH Bosch und Siemens Hausgeräte GmbH
Priority date: 2010-09-03
Filing date: 2011-08-17
Publication date: 2012-03-08
Also published as: EP2611959B1; EA201390268A1; DE102010040189A1; EP2611959A1; CN103237936A; CN103237936B; EA024645B1

Abstract

The invention relates to a method for cleaning a process air channel 5 in a washer/dryer, wherein the washer/dryer has a washing tub 1, a drum 2 which is mounted rotatably in the washing tub 1 for receiving laundry items 3, a control device 18 and the process air channel 5, in which a heater 7 for heating air, a fan 6, a heat exchanger 8 and a transition part 25 between the heat exchanger 8 and the washing tub 1 are situated. The method comprises the following steps: (a) provision of an aqueous liquid 11 in the washing tub 1 and in the transition part 25, with the result that a proportion Q_aq of a cross section Q_tot of the transition part 25 is taken over by the liquid 11; (b) generation of a process air stream 17 of air which is situated in the process air channel 5, at a flow speed v_air, by means of the fan 6; (c) bringing the air flow 17 into contact with the liquid 11 in the washing tub 1 and in the transition part 25, with the result that a mixture of the liquid and the air 15 is formed, wherein the proportion Q_aq and the flow speed v_air of the process air stream 17 are selected in such a way that the mixture 15 is produced in such a way that it does not take up the cross section Q_aw = Q_tot - Q_aq which is not filled with the liquid 11 in the transition part 25; and (d) cleaning of the process air channel 5 by means of the mixture. Moreover, the invention relates to a washer/dryer which is suitable for carrying out this method.

Description

Method for cleaning an airway in a washer-dryer and a suitable washer-dryer for this purpose

The invention relates to a method for cleaning a process air duct in a washer dryer, wherein the washer dryer a tub, a tub rotatably mounted in the tub for receiving laundry, a control device and the process air duct, in which a heater for heating air, a fan, a Heat exchanger and a transition part between the heat exchanger and the tub are, as well as a suitable washer-dryer. Washer dryers are popular for use in confined spaces, because such a device in a space-saving manner combines the functions of a washing machine and a tumble dryer in itself. In addition, a washer-dryer is already provided with a water connection, so that water is not only available for washing laundry but also for further treatment of laundry items.

When drying laundry in a tumble dryer or washer-dryer, fluff generally accumulates due to mechanical action on the laundry to be dried. These lint are removed from the laundry by the process air used for drying and deposited on the walls of the downstream components of the air path (i.e., the channel through which the process air flows from the laundry). The fluff is often stuck to wet spots in the air. These sites include in particular walls of heat exchangers where the deposited lint can adversely affect air circulation and heat exchange. It is therefore a tumble dryer with a self-cleaning function is known in which a heat exchanger is rinsed in a special rinsing step with an aqueous liquid as a rinsing liquid.

Japanese Unexamined Patent Publication No. 1-333185A1 discloses a washer-dryer having a drum in which a drum in a tub is rotatable about an approximately horizontal axis. In a drying process, process air is passed inside the tub and then enters a lower portion of the tub in an exhaust port of a process air duct; In the process air duct, it flows through a pipe system with a fan and a heater and then passes through an opening on the front of the drum back into the tub. Fluff can accumulate in an area of the process air duct in the vicinity of the exhaust air opening. If a washing program is now carried out, in which the water level is higher than the exhaust air opening, part of the water flows into the process air duct. The water flow generated by the rotation of the drum then washes out the lint located there. In addition, an air pressure generated by the fan to fluctuations in the water level in the process air duct lead, whereby the water can also reach a slightly remote from the exhaust port arranged heat exchanger, so that even at the heat exchanger adhesive lint be eliminated. However, the cleaning effect achieved by this distribution of water is often inadequate.

Against this background, the object of the invention was to provide a method by means of which the process air duct can be cleaned in an improved manner in a washer-dryer. The task was also to show a suitable washer-dryer. The washer-dryer should be easy to use and have a simple structure.

The object underlying the invention is achieved by a method and a washer-dryer according to respective independent claim. Preferred embodiments of the invention are listed in the respective dependent claims. Preferred embodiments of the method according to the invention correspond to preferred embodiments of the washer dryer according to the invention and vice versa, even if it is not separately pointed out here in each case.

The invention thus relates to a method for cleaning a process air duct in a washer-dryer, wherein the washer dryer a tub, a drum rotatably mounted in the tub for receiving laundry, a control device and the process air duct, in which a heater for heating air, a fan , a heat exchanger and a transition part between the heat exchanger and the tub are located, in which method the following steps are carried out: (A) providing an aqueous liquid (11) in the tub (1) and in

Transition part (25), so that a proportion Q _aq a cross section Q _to t of the transition part (25) of the liquid (1 1) is taken;

(B) generating a process air flow (17) of air, which is in the process air duct (5), with a flow velocity v _air , by means of the blower (6);

(C) contacting the air flow (17) with the liquid (1 1) in the tub (1) and the transition part (25), so that a mixture of the liquid and the air (15) is formed, wherein the proportion Q _aq and the flow velocity v _a i _r the process air stream (17) are selected such that the mixture (15) is generated such that in the transition part (25) cross-section filled the non with the liquid (11) Q _aw = Q _to t - Q _aq occupies; and

(D) cleaning the process air channel (5) by means of the mixture. Preferably, in this case, the liquid is predetermined in an amount that the drum dips into the liquid in the tub.

Most preferably, the liquid is predetermined in an amount required for a washing or rinsing step in the washer-dryer.

According to the invention, it is preferred that the provision of the liquid takes place within the scope of a washing or rinsing process with laundry items in the drum. This saves time and water. In a preferred embodiment of the method according to the invention, the aqueous liquid is introduced via the heat exchanger. This has the particular advantage that at the same time the heat exchanger can be cleaned. This embodiment is particularly advantageous when the heat exchanger is located in a vertical part of the process air duct.

In general, in a washer-dryer in which the moisture contained in the moist warm air is condensed on a heat exchanger, the heat exchanger is operated with cooling air, cooling water, or as a heat sink in a heat pump. If the heat exchanger is operated with cooling water, it can be provided (by using suitable valves) that the water intended for cooling is conducted as aqueous liquid via the heat exchanger, in particular its wall surfaces, into the tub. The cooling water generally flows downwards through its outer wall surfaces, which are normally in contact with the process air, where the process air duct is connected to the tub via the transition part and thereby cleans the heat exchanger from adhering lint.

On the other hand, if the heat exchanger is cooled with air, a flushing device for the heat exchanger can be present, which cleans the heat exchanger of adhering lint and other impurities. The aqueous liquid may be, for example, a rinsing liquid or a coolant for the heat exchanger. The aqueous liquid is advantageously introduced via a flushing device for the heat exchanger. As a result, the largest part of the process air duct can be cleaned with the method according to the invention.

In an advantageous embodiment of the method according to the invention an air flow is generated during the introduction of the aqueous liquid through the heat exchanger from the fan. This can promote the formation of the mixture of liquid and air and the liquid can be better distributed in the process air duct.

Preferably, in the method according to the invention, the blower is operated for a period of time of from 15 seconds to 5 minutes, more preferably from 30 seconds to 2 minutes and most preferably from 50 to 70 seconds.

In the method of the invention, the drum is preferably rotated. As a result, the formation of the mixture of liquid and air can be advantageously supported.

The aqueous liquid used according to the invention consists essentially or exclusively of water. In general, this will depend on whether the process is carried out as a separate purification process or as part of a wash program or rinse program. In this case, additives may be added to the aqueous liquid which serve for improved purification. The invention also relates to a laundry dryer, comprising a tub, a tub rotatably mounted in the tub for receiving laundry, a control device and a process air duct in which a heater for heating air, a fan, a heat exchanger and a transition part between the heat exchanger and Lye container, wherein the control device for carrying out a method, comprising the steps:

(A) providing an aqueous liquid in the tub and in the transition part, so that a proportion Q _aq a cross-section Q _to t of the transition part of the aqueous liquid is taken;

(B) generating an air flow with a flow velocity v _a i _r in

Process air duct by means of the blower;

(C) contacting the air flow with the aqueous liquid in the tub and in the transition part, so that a water-air mixture is formed;

wherein the proportion Q _aq and the flow velocity v _a i _{r of} the air flow are selected so that a water-air mixture is generated, which occupies the not filled with the aqueous liquid cross-section Q _aw = Q _to t - Q _aq in the transition part,

is set up.

In a preferred embodiment of this washer dryer, a return part is present below the transition part, which connects the transition part in a manner with the tub, that a flow of the aqueous liquid pointing away from the tub in the transition part can flow back into the tub via the return part. Preferably, an inner surface of the transition part on projections, advantageously in particular ribs. As a result, the formation of the mixture of water and liquid can be advantageously influenced.

Before the drum, generally between heating and drum, a temperature sensor T1 is preferably present in the process air duct, with which the temperature of the introduced into the drum or in the tub air can be measured. Further preferably, then the fan and the heater are controlled using the temperature sensor T1 and the controller so that a predetermined Maximum value T _max , eg 65 ° C, for the temperature of the introduced warm air (also known as "blow-in temperature") is not exceeded.

In addition to the air heating, which is arranged in the process air duct, a washer-dryer generally also has a heater for heating a liquid in the tub such. a wash. This heating, referred to herein as water heating, is generally located in the tub below the drum.

The washer-dryer may be equipped with a condensate collecting device, so that as an aqueous liquid in the context of the invention, the resulting condensate in the drying of laundry items can be used.

In general, a washer-dryer has a water supply system with which water can be passed through a generally existing dispenser tray from which detergent or laundry adjuvant portions can be added to the washer-dryer. In embodiments of the invention, such a water supply system preferably also has a branch to the heat exchanger in order to be used there as rinsing water in a rinsing device for the heat exchanger or as a cooling liquid for carrying out the method according to the invention.

A washer-dryer generally has a lye drainage system arranged at the bottom of the lye container with a drain pump as well as generally laundry hoppers and / or scooping devices. Preferably, a washer-dryer according to the invention also contains a pressure sensor and / or a temperature sensor in the tub, which are preferably arranged in a lower region of the tub, so that the pressure and / or the temperature of an aqueous liquid present in the tub can be measured.

The invention has numerous advantages. The process air duct of a washer dryer, in particular horizontally lying parts thereof, can be cleaned in a simple manner without additional water consumption. The invention can easily be integrated into washing and / or rinsing programs, in particular since no change in the use values is necessary. So it can be used a otherwise conventional washer-dryer without the need for any special modifications other than the appropriate control unit.

The invention will be explained below with reference to Figures 1 and 2 on. Figure 1 shows a washer-dryer according to a first embodiment, which has a heat exchanger in a vertical part and a fan in a horizontal part of the process air duct in a process air duct.

Figure 2 shows a section of a washer-dryer according to a second embodiment, which has a fan and a heat exchanger in a vertical part of the process air duct.

1 shows a washer-dryer according to a first embodiment, which has a heat exchanger 8 in a vertical part and a fan 6 in a horizontal part of the process air duct 5 in a process air duct 5. Other embodiments are conceivable.

The washer-dryer shown in FIG. 1 has a tub 1 and a drum 2 rotatably mounted therein about a substantially horizontal axis, in which laundry items 3 are located. The tub 1 is connected via a Laugenablaufleitung 19 with a drain pump 12, which can dispose of an aqueous liquid 11 from the tub 1 via a sewer 13 to the outside of the washer dryer. The drum 2 is driven by means of a drive motor 4. The drum 2 is loaded through a filling opening 22 with laundry items 3 to be treated. To wash clothes in the washer-dryer, the washer-dryer is connected via a water supply system 20 to an external water supply not shown here. The water supply system 20 is connected to a dispensing bowl 21, from which with the aid of water from the water supply system 20 detergent or Waschhilfsmittelportionen can be transported into the tub 1. In the present case, this takes place via a part of a process air channel 5 and a sleeve 23. For drying damp laundry in the drum 2, in the washer-dryer of Figure 1, which operates on the recirculation principle, the air heated by means of a heater 7 ("process air") is conveyed through the fan 6 in the process air duct 5. Here, heated process air passes over the cuff After passing through the drum 2 and receiving moisture from the wet laundry items 3 located there, the then humid process air passes through a rear outlet 24 from the tub 1 to the heat exchanger 8, where the in Alternatively, the condensate can flow via a transition part 25 between the heat exchanger 8 and the tub 1 back into the tub 1, from where it via the Laugenablaufleitung 19 with the drain pump 12 via the sewer 13 after can be disposed of outside the washer dryer D The dehumidified process air then continues to flow in the process air duct 5, is heated again by the heater 7 and passes through the sleeve 23 back into the drum 2. In the washer-dryer of Figure 1 below the transition part 25, a return member 16 is present, which the transition part 25 to a Way with the tub 1 connects, so that a flow in the transition part 25 from the tub 1 effluent flow of the aqueous liquid 1 1 via the return part 16 back into the tub 1 can flow. The inner surface 26 of the transition piece 25 has projections, in this case ribs. As a result, the formation of a mixture 15 of moisture and air can be advantageously influenced.

To carry out the new method, an aqueous liquid 11, in particular water, wash liquor or rinsing liquor, is predetermined in the washer-dryer in such a quantity that the drum 2 dips into the liquid 11 in the tub 1. This is an amount required for a washing or rinsing step in the washer-dryer. The provision of the aqueous liquid 11 takes place here as part of a washing or rinsing process with laundry 3 in the drum 2. The liquid 1 1 is provided in the tub 1 and the transition part 25 in an amount that a proportion Q _aq a cross-section Q _to t of the transition part 25 is occupied by the liquid 11. In addition, an air flow 17 is generated at a flow velocity v _a i _r in the process air duct 5 by means of the blower 6. Of the Air flow 17 is brought into contact with the liquid 1 1 in the tub 1 and the transition part 25, so that a mixture 15 of liquid and air, in particular a mist, a foam or a complex composition of the two forms, wherein the proportion Q _aq and the flow rate v _a i _{r of} the air flow 17 are selected so that the mixture 15 is generated such that it occupies the not filled with the aqueous liquid 11 cross-section Q _aw = Q _to t - Q _aq in the transition part.

Due to the existing below the transition part 25 recirculation part 16, which connects the transition part 25 in a manner with the tub 1, that in the transition part 25 from the tub 1 effluent flow of the liquid 11 can flow back into the tub 1 via the return part 16, there is a movement of the liquid 1 1 in a circuit.

In carrying out the method of this embodiment, liquid 11 is also introduced via a flushing device 10 for the heat exchanger 8 via the heat exchanger 8 in the tub 1. In this way, in the context of a washing or rinsing process, thus also the heat exchanger 8 can be cleaned of adhering lint 27. During the introduction of the liquid 1 1 via the heat exchanger 8 in this case the air flow 17 is generated by the fan 6.

The fan 6 and the heater 7 are controlled using a temperature sensor T1, 14 and a controller 18 so that a predetermined maximum value T _max for the temperature of the air flow in the process air duct 5, here 65 ° C, is not exceeded. The flushing device 10 is connected via a water valve 9 with a water supply of the washer dryer not shown here. The liquid 1 1 passes through the transition part 25 and a rear exit 24 into the tub 1.

The process air stream 17 is shown in Figure 1 by large arrows.

Figure 2 shows a section of a washer-dryer according to a second embodiment, which has a fan and a heat exchanger in a vertical part of the process air duct. The aqueous liquid 1 1 is provided in the tub and in the transition part 24 in an amount such that a proportion Q _{aq of} a cross-section Q _to t of the transition part 24 is occupied by the aqueous liquid 1 1. Due to the projections 26, here ribs, provided inner surface 26 of the transition part 25, the proportion Q _aq can vary over the length of the transition part 25. The cross section of the transition part 25 is here measured generally perpendicular to a longitudinal axis of the transition part 25, not shown here.

An air flow 17 is generated at a flow velocity v _a i _r in the process air duct 5 by means of the blower 6. The air flow 17 is brought into contact with the liquid 11 in the tub not visible here and in the transition part 24, so that a mixture 15 of liquid and air is formed. The proportion Q _aq and the flow velocity v _{air of} the air flow 17 are selected so that the mixture 15 is generated such that it occupies the not filled with the liquid 11 cross-section Q _aw = Q _to t - Q _aq in the transition part 24. In this way, the transition part 25 and, if necessary, the heat exchanger 8 can be efficiently cleaned of adhering lint 27.

LIST OF REFERENCE NUMBERS

1 tub

2 drum

3 pieces of laundry

4 drive motor

5 process air duct

6 blowers

7 heating

8 heat exchangers

9 water valve

10 Flushing device for heat exchangers

11 Aqueous liquid

12 wastewater pump

13 sewer pipe

14 Temperature sensor T1 between drum and air heater

15 water-air mixture

16 feedback part

17 airflow

18 control device

19 Lye drain line

20 water supply system

21 induction bowl

22 filling opening

23 cuff

24 rear exit (from the tub)

25 transition part

26 inner surface of the return part; Projections, ribs

27 lint

Claims

Method for cleaning a process air duct (5) in a washer-dryer, wherein the washer dryer comprises a tub (1), a drum (2) rotatably mounted in the tub (1) for receiving laundry items (3), a control device (18) and the process air duct ( 5), in which a heater (7) for heating air, a fan (6), a heat exchanger (8) and a transition part (25) between the heat exchanger (8) and the tub (1) are located, characterized by the Steps:

(E) providing an aqueous liquid (11) in the tub (1) and in the transition part (25), so that a proportion Q _aq a cross section Q _to t of the transition part (25) of the liquid (1 1) is taken;

(f) generating a process air stream (17) of air, which is located in the process air duct (5), with a flow velocity v _air , by means of the blower (6);

(G) contacting the air stream (17) with the liquid (1 1) in the tub (1) and the transition part (25), so that a mixture of the liquid and the air (15) is formed, wherein the proportion Q _aq and the flow velocity v _a i _r the process air stream (17) are selected such that the mixture (15) is generated such that in the transition part (25) cross-section filled the non with the liquid (11) Q _aw = Q _to t - Q _aq occupies; and

(h) cleaning the process air channel (5) by means of the mixture.

A method according to claim 1, characterized in that the liquid (1 1) is set in an amount that the drum (2) in the liquid (11) in the tub (1) is immersed.

A method according to claim 1 or 2, characterized in that the liquid (11) is predetermined in an amount which is required for a washing or rinsing step in the washer-dryer.

Method according to one of the preceding claims, characterized in that the provision of the liquid (11) as part of a washing or rinsing process with laundry pieces (3) in the drum (2).

Method according to one of the preceding claims, characterized in that the liquid (11) via the heat exchanger (8) is introduced into the tub (1).

A method according to claim 6, characterized in that the liquid (1 1) via a flushing device (10) for the heat exchanger (8) is introduced.

Method according to one of claims 6 and 7, characterized in that during the introduction of the liquid (11) via the heat exchanger (8) from the fan (6) an air flow (17) is generated.

Method according to one of the preceding claims, characterized in that the blower (6) is operated for a period of time Et of 15 seconds to 5 minutes.

Method according to one of the preceding claims, characterized in that the drum (2) is rotated.

Washer dryer, comprising a tub (1), a tub (1) rotatably mounted in the drum (2) for receiving laundry items (3), a control device (18) and a process air duct (5) in which a heater (7) for Heating of air, a fan (6), a heat exchanger (8) and a transition part (25) between the heat exchanger (8) and tub (1) are located, characterized in that the control device (18) is adapted to perform a method comprising the steps:

(A) providing an aqueous liquid (1 1) in the tub (1) and in the transition part (25), so that a proportion Q _aq a cross section Q _to t of the transition part (25) of the aqueous liquid (11) is taken;

(B) generating an air flow (17) with a flow velocity v _air in the process _air duct (5) by means of the blower (6); (C) contacting the air flow (17) with the liquid (1 1) in the tub (1) and the transition part (25), so that a mixture of the liquid and the air (15) is formed, wherein the proportion Q _aq and the flow rate v _a i _{r of} the process air stream (17) are selected so that the mixture (15) is generated in such a way that in the transition part (25) the cross-section Q _aw = Q _to t not filled with the liquid (1 1) Q _aq occupies; and

(D) cleaning the process air channel (5) by means of the mixture.

Waschtrockner according to claim 10, characterized in that below the transition part (25) a return part (16) is present, which connects the transition part (25) in a manner with the tub (1), that in the transition part (25) away from the tub (1) pointing flow of the aqueous liquid (11) via the return part (16) back into the tub (1) can flow.

Washer dryer according to one of claims 10 and 11, characterized in that an inner surface (26) of the transition part (25) has projections.

13. Waschtrockner according to claim 12, characterized in that the

Surface (26) of the transition part (25) has ribs (26).