EP2202349B1 - Laundry drying device and method for cleaning a filter - Google Patents

Description

The invention relates to a laundry drying appliance, having a sieve for sifting out bodies, in particular fluff, from a process air stream flowing through a process air duct of the laundry drying appliance, and having a cleaning device for cleaning the sieve, the sieve being arranged in space at an angle (α ) is arranged obliquely, at least one cleaning opening for supplying a cleaning liquid onto a screen surface of the screen is arranged at an upper portion of the screen, and the screen is stationary. The invention also relates to a method for cleaning a filter of such a laundry drying device.

Such a laundry drying device emerges from each of the documents DE 42 12 965 A1 , WO 2009/015919 A1 (published only after the priority date and before the filing date of the present patent and thus falling under Article 54(3) EPC) and U.S. 2006/0123854 A1 .

From the DE 100 02 743 A1 is a heat pump tumble dryer with a cleaning device for the heat exchanger. From the EP 0 269 864 A1 the result is a filter device with liquid-wetted filter elements for a ventilation system. From the KR 10 2007 0076853 A The result is a tumble dryer with a fluff filter that can be cleaned with a liquid. From the JP H06 2907 A the result is a filter for a ventilation device which can be cleaned by means of a liquid and which is positioned at an angle with respect to a gas stream flowing through.

In laundry drying devices such as tumble dryers or washer-dryers, the use of screens to clean process air is known. In tumble dryers, such a filter is arranged as a fluff filter in a process air duct leading away from the drum housing. When laundry is dried in a laundry drum inside the drum housing, bodies, in particular fluff, are carried away by the laundry with the process air as the process medium and are carried along with the process air in the process air duct. The screen serves to screen out such fluff from the process air, so that the fluff cannot reach a condenser for drying the process air and settle there. This would increase the efficiency of the deteriorate the capacitor. Previously, such filters could be removed and then cleaned manually in order to remove fluff adhering to the filter.

From the scriptures EP 1 788 140 A1 , EP 1 788 141 A2 and EP 1 788 141 A2 a dryer for drying laundry by means of an air flow is known. In the dryer, a screen for filtering lint from an air flow in the process air duct is arranged in the area of an end shield, which screen forms a first lint filter. The fluff collected in the process air duct on the filter is scraped off the filter fabric of the fluff filter by means of a squeegee and stored in a container arranged adjacent to the squeegee and the filter. The squeegee and the container thus form, together with other components, a first cleaning device. However, due to the space available in the area of the squeegee, the container has relatively small dimensions. Fluff from around 7 to 10 drying processes can be collected in it. Since the fluff is stored in the dry state, it takes up a relatively large volume. On the one hand, access to the collection container is restricted in these dryers, and on the other hand the collection volume is limited by its arrangement in a space-limited zone of the dryer, resulting in a relatively frequent maintenance interval for disposing of the fluff from the container. The dryer features furthermore via a heater as a heat source and an air-to-air heat exchanger as a heat sink in the process air duct.

U.S. 2006/0123854 A1 relates to a washing machine combined with a dryer. In the washing machine, a cabinet is provided, a tub is installed in the cabinet, a vent hose is attached to an outer surface of the tub, a lint filter assembly has an end connected to the vent hose to remove lint from air exiting the tub is vented and a vent line is connected to the other end of the lint filter assembly. The lint filter assembly collects lint from the moist air flowing through it. The collected lint deposits on a filter of the lint filter assembly, and the deposit of the lint is removed by injecting water from a water inlet pipe onto the filter from the front. The removed fluff is fed into the tub through the vent hose. The lint filter assembly installed in the cabinet is inclined at a predetermined angle toward the front of the washing machine so that a user can easily remove the filter unit from the front of the washing machine and repair the lint filter assembly.

WO 2009/015919 A1 relates to an arrangement for automatically cleaning air filters, in particular those designed for use as applied to the drying circuit of a washing machine for clothes, which operates according to a heat pump principle, having at least one sharp-jet injection nozzle for injecting liquid and at least one air filter unit, wherein the liquid injection nozzle is mounted so as to be able to move relative to a fixed frame, the relative movement being brought about by at least one actuator means connected thereto. The air filter unit and/or the liquid injection nozzle can be connected to the frame by means of a four-bar linkage. Here, the relative movement of the air filter unit to the injection nozzle is required for cleaning, which requires a high level of equipment and a large amount of space.

It is the object of the present invention to provide a possibility for particularly efficient cleaning of a filter, in particular a fluff filter, in a laundry drying appliance.

This object is achieved by means of a laundry drying device and by means of a method for cleaning a filter according to the respective independent claim. Preferred embodiments can be found in particular in the dependent claims.

The laundry drying appliance according to the invention, having a sieve for sifting out bodies, in particular fluff, from a process air flow flowing through a process air duct of the laundry drying appliance, and having a cleaning device for cleaning the sieve, the sieve being inclined in space at an angle (α) relative to the process air flow flowing through is arranged, at least one cleaning opening for supplying a cleaning liquid to a screen surface of the screen is arranged in an upper area of the screen and the screen is stationary, is characterized in that the process air duct has a substantially vertical extension at least in the area of the screen, and namely with a flow direction of a process air guided in the process air duct running predominantly from top to bottom.

Such a filter can easily be cleaned of adhering lint without manual intervention on the part of a user of the household appliance by means of an automatically operated cleaning device, which flushes a cleaning liquid over the lint filter in such a way that the adhering lint is removed from a filter surface of the filter. The screen is arranged in space at an angle relative to the flow of process air flowing through. As a result, a cleaning liquid applied to the screen, e.g. B. water, drain automatically and take fluff etc. with you. Consequently, the cleaning liquid does not have to be applied under high pressure, which saves costs and installation space, for example for a printing device, nor are there areas with standing water, which results in a good cleaning effect. However, applying the cleaning liquid under pressure can further increase the cleaning performance.

The sieve is installed stationary (and is therefore not specifically moved for cleaning) in order to achieve a simple arrangement. The effective cleaning effect can be made possible in particular by arranging the cleaning opening in the upper area.

According to the invention, the process air duct has, at least in the area of the screen, a substantially vertical extension (i.e. vertical or deviating insignificantly for the purpose) with a flow direction of a process air guided in the process air duct running predominantly from top to bottom, which is very streamlined and advantageous for one the cleaning liquid is drained.

At least one cleaning opening for supplying the cleaning liquid to a screen surface of the screen is arranged in an upper area of the screen. As a result, the cleaning liquid can be applied to the screen surface particularly easily in a compact design. The arrangement in an upper area can in particular include the cleaning opening being arranged above, in particular essentially directly above, the screen. In other words, the cleaning opening can essentially directly border the screen. As a result, the cleaning liquid can be applied to the screen in a particularly simple and complete manner.

For easy distribution of the cleaning liquid across the width of the screen, the at least one cleaning opening can lead to a common liquid line and/or to a common inflow chamber of the cleaning device.

The at least one cleaning opening can be embodied as a nozzle for an increased cleaning effect, even in the case of bodies adhering to a greater extent on the filter, in particular fluff. A large-area wetting of the screen can also be ensured by shaping the nozzle jet. A cleaning liquid can be directed through a nozzle and guided over the screen surface of the screen with increased entraining force.

In order to maximize a flow rate of the cleaning liquid on the screen, the at least one cleaning opening can be aligned flush with the screen surface of the screen.

In order to optimize the cleaning effect, however, it can also be advantageous if the at least one cleaning opening is aligned at an angle, in particular a small angle, to the surface of the screen. The angle is advantageously less than 5°.

The liquid line preferably opens into an inflow chamber, which is partially separated from the at least one cleaning opening by an intermediate wall. This enables the cleaning liquid to be distributed more evenly over a large number of such cleaning openings. The inflow chamber can have a bypass on the underside for draining residual water, so that it does not remain in it and cause unpleasant odors over time.

A discharge channel can be formed in a lower area of the screen for disposal of cleaning liquid conducted over the screen. This preferably bypasses the condenser and ends behind the condenser again in the process air duct. Used cleaning liquid can thus be disposed of together with condensed water from the condenser, so that no separate disposal means need to be provided.

At least a section of the discharge channel adjacent to the screen can be integrated with the screen. In this way, it can be achieved that no projections such as sharp edges, burrs, etc., on which fluff etc. could get caught, occur at the transition from filter to drain channel. This supports a complete cleaning of the sieve. For this purpose, it can be particularly advantageous if a screen surface of the screen is arranged higher or flush with it in a transition area to the discharge channel.

For simple implementation and for a compact design, the cleaning device can be installed in a bearing plate, in particular a front bearing plate. In other words, the cleaning device can be installed in a particularly compact and streamlined manner in a front process air duct, which is directly connected to a laundry drum. As a result, pressure losses in the process air can be avoided, e.g. B. could be caused by turbulence.

It can be particularly preferred if the screen is integrated into the cleaning device, since this minimizes manufacturing tolerances and improves the cleaning result. It is particularly preferred if the at least one cleaning opening is integrated into a screen frame of the screen. It is also particularly preferred if the discharge channel or a part thereof adjoining the screen is integrated into the screen frame.

The sieve can be permanently installed or removable in the laundry drying device.

In the inventive method according to claim 13, the screen of a laundry drying device is cleaned by means of a cleaning device, wherein the screen is arranged at an angle obliquely in space and a cleaning liquid advantageously from above over the obliquely built-in Sieve is passed. In particular, the guiding can be essentially pressureless pouring.

The activation of the method can be triggered automatically by a control device of the household appliance as required, in fixed cycles and/or manually.

• FIG 1 zeigt schematisch und in teilweiser Schnittansicht einzelne Komponenten eines Wäschetrockners mit einem als Flusensieb ausgestalteten Sieb und mit einer Reinigungseinrichtung zum Reinigen des Siebs und
• FIG 2 zeigt schematisch eine demgegenüber modifizierte Reinigungseinrichtung.

In the following figures, the invention is described schematically in more detail using an exemplary embodiment. For the sake of clarity, elements that are the same or have the same effect are provided with the same reference symbols.

• FIG 1 shows schematically and in a partial sectional view individual components of a tumble dryer with a filter configured as a fluff filter and with a cleaning device for cleaning the filter and
• FIG 2 shows schematically a cleaning device modified in comparison.

FIG 1 shows components of a laundry drying device 1, such as a tumble dryer or washer-dryer. The laundry drying device 1 has a laundry drum 3, which is used to dry laundry 4 placed therein. When drying the laundry 4, the process air L located in the laundry drum 3 is humidified, with bodies F such as fluff also getting into the process air L.

The process air L is discharged from the laundry drum 3 via a process air duct 5 connected to it. A lint filter 7 extends through the process air duct 5 in order to filter or sift out at least a portion of the bodies F from the process air. These are, for example, a condenser or a heating device, which are used to dehumidify or heat up the cleaned process air L* before the cleaned process air L* is blown back into the laundry drum 3 .

At the in FIG 1 In the arrangement shown, the process air duct 5 runs vertically from top to bottom in the area with the fluff filter 7 inserted therein. The fluff filter 7 is used at an angle α obliquely through the process air duct 5 leading into this. Accordingly, the process air flow flowing through the process air duct 5 flows through it obliquely. A fluff filter cleaning device 9 , which flushes fresh water W over the fluff filter 7 as a cleaning liquid, serves to clean the fluff filter 7 .

Due to the oblique orientation of the fluff filter 7, the cleaning liquid W runs over or along a fluff filter surface of the fluff filter 7 to its lower area. In the lower area, in particular at the lowest point of the fluff filter 7, there is a discharge channel 13, the section of which adjoining the fluff filter 7 is part of a fluff filter housing 10, in particular a filter frame. The discharge channel 13 allows the cleaning liquid W* that has flowed over the surface of the fluff filter and is therefore soiled to exit. The soiled cleaning liquid W* is conducted via a channel 13 to a liquid container 8 for transport. The liquid tank 8 is a condensate water tank in which condensate water discharged from the condenser is also collected. The cleaning liquid W is supplied from a fresh water line 18 . For uniform distribution over the surface of the lint filter 7 , the cleaning device 9 has an inflow chamber 11 in the entry area of the liquid line 18 . The actual spraying of the cleaning liquid W onto the lint filter surface of the lint filter 7 takes place via one or more nozzles 16. More precisely, the inflow chamber 11 is divided into two shell-shaped parts by an upwardly open partition 14, with a first, inner chamber 11a directly connected to the nozzles 16 is connected and a second, outer chamber 11b is flowed through by the liquid line 18. In operation, cleaning liquid thus flows into the outer chamber 11b and fills it up, and when the upper edge of the intermediate wall 14 is reached, the cleaning liquid overflows into the inner chamber 11a and from there reaches the nozzles 16. In order to finally be able to drain the inflow chamber 11 after the cleaning process by means of the cleaning device 9 or when the laundry drying appliance 1 is switched off, a bypass 15 is formed in the lower region of the intermediate wall 14 . The bypass 15 preferably has a relatively small diameter through which residual water can drain.

The starting point is therefore that the fluff filter 7 is used in a process air duct 5 of a washing machine or tumble dryer 1 . The fluff filter 7 preferably has a surface with a functional coating, in particular a hydrophobic coating, which makes it difficult for bodies F to adhere firmly. To clean off the bodies F, in particular lint, that have accumulated on the lint filter 7 , the cleaning liquid W is flushed over the lint filter 7 in order to detach the bodies F located thereon from the surface of the lint filter by means of the cleaning liquid W and transport them away from the lint filter 7 . By reducing the number of components for cleaning the fluff filter, in that the fluff filter itself functions as a functional component of the cleaning device 9 due to its spatially inclined position, tolerances in the cleaning result are advantageously kept low. The cleaning device 9 for applying the cleaning liquid W is integrated into the fluff filter 7 .

The fluff filter material preferably consists of metal or has metal. For use in a damp environment, such as in a tumble dryer or a washing machine, the fluff filter material is preferably made of corrosion-resistant material, in particular of a material that is corrosion-resistant to the action of lye or water. In particular, high-grade steel or aluminum can advantageously be used as the fluff filter material, which are temperature-resistant and, if necessary, can easily be given a hydrophobic coating with suitable finishing materials. It is preferred if such a hydrophobic finish is implemented as a nano-varnish and/or causing a lotus effect on or on the fluff filter material. The fluff filter material with the equipment is preferably arranged as a woven fabric, scrim or as a perforated foil or sheet.

Advantageously, with such an arrangement, it is no longer necessary for a user of the laundry drying device 1 to remove the fluff filter 7 . However, the lint filter 7 can preferably be removed from the process air duct 5 and the lint filter cleaning device 9 in order to allow a service technician access for service purposes.

While the nozzle 16, as in FIG 1 shown, for the distribution of the cleaning liquid W on or over the surface of the fluff filter can be aligned flush with the upper side of the fluff filter fabric of the fluff filter 7, there is also the possibility according to FIG a modified embodiment, the nozzle 19 as in FIG 2 shown to employ at an angle to the fluff filter surface. The cleaning effect can be optimized by a suitable choice of an inflow angle, which can also be adjusted in particular in connection with an inclination of the fluff filter 7 relative to the surrounding space.

In addition to a preferably precise and reproducible arrangement of the nozzle 16 for cleaning the lint or bodies F from the lint filter 7, the bodies F are preferably also removed from the lint filter 7 by means of the cleaning liquid W via an outlet in the form of the outflow chamber 12, which is integrated in the lint filter 7 is. The design is chosen so that in the transition area between the fluff filter 7 or its surface and an adjacent peripheral wall of the outflow chamber 12 there are no sharp edges, burrs, etc., on which such bodies F can get caught or become stuck, which means that cleaning is complete would prevent. As with the nozzle 16, the lower edge of the transport channel or the outflow chamber 12 is aligned flush with the upper side of the fluff filter fabric.

Particularly preferred is an arrangement of the cleaning device 9 with the fluff filter 7 and the duct for the removal 13 streamlined in the front process air duct, in particular in the area of the front end shield. As a result, pressure losses in the process air L by z. B. turbulence avoided.

An embodiment as in FIG 1 , in which the nozzle or nozzles 16 for distributing the cleaning liquid on the fluff filter 7 are integrated into the fluff filter housing 10 or into a fluff filter frame of the fluff filter 7 to improve the cleaning effect. It is also preferred if, in order to improve the lint removal from the lint filter 7 , the channel for the removal 13 or the outflow chamber 12 is integrated into a lower section of the lint filter frame of the lint filter 7 .

Of course, the present invention is not limited to the embodiment shown.

Preferably, an angle α to the lint filter extension of the surface of the lint filter 7 relative to the process air duct extension z and/or relative to the vertical in the space around the lint filter 7 is selected so obliquely that a cleaning liquid sprayed in the upper area onto the lint filter surface of the lint filter 7 over the Lint filter surface can easily drain to the outflow chamber 12 arranged on the underside. Thus, in particular, the gravitational force is utilized, which causes the cleaning liquid W to drain over the surface of the lint filter 7 from the nozzle(s) 16 to the lint filter outflow chamber(s) 12 . The gravitational effect is supported, particularly in the case of close-meshed fluff filters, by the process air L being pressed against the fluff filter surface or sucked through it, or by spraying the cleaning liquid by means of the nozzle 16 , 19 .

Instead of supplying the cleaning liquid W from the liquid container 8, a cleaning liquid can also be supplied from another liquid container or from a fresh water line. Also, the dirty cleaning liquid W* does not necessarily have to be introduced into the liquid container 8, which is used to hold condensate water. Alternatively, the soiled cleaning liquid W* can also be introduced into a separate liquid container or discharged directly from the laundry drying device 1 via an outlet.

The cleaning device 9 can in particular consist of a one-piece fluff filter housing 10 which is arranged obliquely in space. It is also possible to implement an in FIG 1 preferably outlined variant, in which the process air duct 5 has beveled tube wall ends and engages from two sides in corresponding receptacles of the cleaning device 9 or of its fluff filter housing 10 .

The channel 13 for transporting the soiled cleaning liquid W* away can also be used as an independent component, for example as a hose in an outlet opening of the outflow chamber 12 .

The exemplary sequence of components of the tumble dryer as a tumble dryer 1 can also be in a different order. In particular, such a fluff filter 7 not only needs to be arranged in the process air duct 5 directly behind the drum housing 2, but can also be arranged at any other point in the process air duct 5. The use of such a fluff filter 7 in a differently designed process air duct is also possible, for example in an air supply duct or in an air discharge duct, which lead to the outside of the laundry drying device 1 and are not designed as a closed process air circuit.

Reference List

1

laundry drying machine

3

laundry drum

4

Laundry

5

process air duct

6

Interior of the process air duct

7

fluff filter

8th

liquid container

9

sieve cleaning device

10

screen housing

11

inflow chamber

11a

inner chamber part

11b

outer chamber part

13

channel for transport

14

partition

15

bypass

16

jet

17

fluid reservoir strainer

18

liquid line

19

alternative nozzle

f

body, especially fluff

L

process air

L

cleaned process air

W

cleaning fluid

W*

dirty cleaning fluid

e.g

Process Air Duct Extension

a

angle

Claims (14)

1. Laundry drying device (1), having a filter (7) for the filtering-out of matter (F), in particular fluff, from a process air stream flowing through a process air channel (5) of the laundry drying device (1), and having a cleaning device (9) for cleaning of the filter (7), wherein the filter (7) is arranged in the compartment inclined at an angle (α) relative to the through-flowing process air stream, at least one cleaning opening (16) for direction of cleaning liquid (W) onto a filter surface of the filter (7) is arranged in an upper region of the filter (7) and the filter (7) is stationary, characterised in that the process air channel (5) has an essentially vertical extension, at least in the region of the filter (7), with a direction of flow of the process air (L) in the process air channel (5) which is largely from top to bottom, so that cleaning liquid applied to the filter can drain away autonomously.
2. Laundry drying device (1) according to claim 1, characterised in that the at least one cleaning opening (16) leads to a liquid line (18) and / or an inflow chamber (11) of the cleaning device (9).
3. Laundry drying device (1) according to one of the preceding claims, characterised in that the at least one cleaning opening (16) is embodied as a nozzle (16).
4. Laundry drying device (1) according to one of the preceding claims, characterised in that the at least one cleaning opening (16) is oriented flush to the filter surface of the filter (7).
5. Laundry drying device (1) according to one of the preceding claims, characterised in that the at least one cleaning opening (16) is oriented at an angle to the filter surface of the filter (7).
6. Laundry drying device (1) according to one of claims 2 to 5, characterised in that the liquid line (18) ends in an inflow chamber (11), which is partially separated from the at least one cleaning opening (16) via a partition (14).
7. Laundry drying device (1) according to claim 6, characterised in that a through-opening (15) for the drainage of residual water leads through the partition.
8. Laundry drying device (1) according to one of the preceding claims, characterised in that a drain channel (12) is embodied in a lower region of the filter (7) for drainage of cleaning liquid (W^∗) directed over the filter (7).
9. Laundry drying device (1) according to claim 8, in which at least one section of the drain channel (12) bordering the filter (7) is integrated with the filter.
10. Laundry drying device (1) according to claim 8 or 9, characterised in that a filter surface of the filter (7) is arranged at a higher level or flush in a transitional area to the drain channel (12).
11. Laundry drying device (1) according to one of the preceding claims, characterised in that the cleaning device (9) is built into an end plate, in particular a front end plate.
12. Laundry drying device (1) according to one of the preceding claims, characterised in that the filter (7) is integrated in the cleaning device (9).
13. Method for cleaning a stationary filter (7) of a laundry drying device (1), having a filter (7) for the filtering-out of matter (F), in particular fluff, from a process air stream flowing through a process air channel (5) of the laundry drying device (1), and having a cleaning device (9) for cleaning of the filter (7), wherein the filter (7) is arranged in the compartment inclined at an angle (α) relative to the through-flowing process air stream, and wherein a cleaning liquid (W) is directed from above over the obliquely built-in filter (7), characterised in that the process air channel (5) has an essentially vertical extension, at least in the region of the filter (7), with a direction of flow of the process air (L) in the process air channel (5) which is largely from top to bottom, so that cleaning liquid applied to the filter can drain away autonomously.
14. Method according to claim 13, in which the cleaning liquid (W) is poured from above over the obliquely built-in filter (7).

Images