DK2226421T3

DK2226421T3 - Household appliance, especially dryer

Info

Publication number: DK2226421T3
Application number: DK10000744.2T
Authority: DK
Inventors: Andre Widmer
Original assignee: V Zug Ag
Priority date: 2010-01-26
Filing date: 2010-01-26
Publication date: 2014-03-10
Also published as: PL2226421T3; EP2226421B1; EP2226421A1; SI2226421T1

Description

Field of the invention

The invention relates to a household appliance, particularly a dryer for drying textiles.

Background

Laundry dryers dry the humide or wet textiles inserted into a drying space, e.g. a drum, by supplying hot air into the drying space. The hot air absorbs the humidity from the textiles. The exhaust air saturated by humidity in this way is fed into a heat exchanger or released into the environment, depending on the construction of the laundry dryer. The hot, humid air is cooled down in the heat exchanger and releases the humidity as water into a collecting basin. In the following the now dry, cool air is heated up and ensures in this way a better reception of humidity in the drying space. This dry, hot air is again supplied to the drying space .

An air filter element for discharging particles from the air stream in general and particularly from textile fluffs, also known as fluff filter, is arranged between the drying space and the heat exchanger in the closed air circuit of such a so-called condensation dryer. During the drying process itself the dry, hot air doesn't only absorb the humidity of the textiles to be dried, as desired, but also textile particles like fluffs or other depositions of the laundry, caused by the mechanic stress of the textiles due to the air stream, the drum rotation, etc.. Without a filter element as mentioned structures of the following heat exchanger can be contaminated by such particles. In case of exhaust air driers a filter element may also be used with the purpose of reducing the contamination of the environment with particles.

In order to avoid that the function of such filter elements is affected, they have to be cleaned regularly. Furthermore such a filter element should be replaced in case of wear or malfunction. Consequently, available filter elements are typically arranged in an easily accessible way in the laundry dryer and can be cleaned or replaced manually.

For an easier maintenance and a comfortable handling of such a laundry dryer partially or fully automatic cleaning mechanisms for filter elements have been developed. The device normally used for cleaning the filter element is a so-called wiper for wiping off the particles stuck more or less strongly to the filter element, particularly textile fluffs.

In this case a band-shaped filter element with its ends not necessarily containing filter material is stretched on two drums via deflecting rollers, of which drums at least one is actuated by an electric motor. A cleaning device is arranged between the filter surface and the second drum. In order to clean the filter element, the filter material is wrapped from the first drum to the second drum until the part covered by fluffs of the filter has been entirely guided along the cleaning device and cleaned in this process. Such a filter device is known from the German utility model G 94 13 742.0 U1 and is described as used in a tunnel finisher for smoothing clothes.

The described filter device requires a large space in the drying device. Particularly in case of compact household dryers, with regard to their dimensions, the space is limited. DE 82 24 528 U1 shows a filter element for a laundry dryer as well as a wiper brush of roller-type, which is rotated when pulling out the filter element upwards and the fluffs on the filter element are wiped off during this process. The brush itself is cleaned by a type of comb. FR 2 931 489 Al shows a filter element for a laundry dryer. The filter element protrudes vertically. A wiper is moved on the filter element between two positions A and B.

The document US 2008/235978 A1 shows a tubeshaped filter element for a laundry dryer, which is rotatably supported inside a casing. The rotation may be performed by motor. The discharge air is supplied to an exterior side of the filter element. Accordingly, scrape elements are arranged on the exterior of the filter element, which scrape off the fluffs attached to the outer surface of the rotating filter element.

The document WO 01/96647 A1 also shows a filter installation for a laundry dryer. In this case the discharge air exits the drum radially and streams through a filter element arranged inside a stationary metal sheet and has the shape of a quarter cylinder. Wipers cleaning the interior of the filter element are arranged at the drum.

The document DE 90 00 624 U1 shows a laundry dryer with a circulating, round filter element, the motion course of which is located, in a first section, in the streaming path of the dry air stream from the exit out of the drying drum towards the heating device, the filter element having a fluff aspirating device in a second section.

Description of the invention

This gives rise to the need of providing a household appliance with a compact filer device allowing an automatized cleaning of the filter element. This objective is reached by a household appliance with the features of claim 1. According to the claim the filter element and the cleaning device are rotatable with respect to one another.

As a consequence of the cleaning by rotating the elements with respect to one another, it is possible to provide a filter device which is substantially more compact with respect to its dimensions and which at the same time has the same active filter surface than e.g. when using a band-shaped filter element.

Further preferred embodiments show that also an actuator for the automatized initiation of a rotation between the filter element and the cleaning device for cleaning the filter element only requires little space. As a consequence of this small dimensions such a filter device is particularly suited for usage in household appliances .

Embodiments are described, which can be used in household appliances with very different constructions and also allow an automatized operation without requiring an undue space .

In other embodiments advantageous arrangements of such filter devices in a household appliance are described.

Further advantageous embodiments of the invention are characterized by the features of the dependent claims, taken alone or in combination with the features of other dependent claims.

Short description of the drawings

Further embodiments, advantages and applications of the invention result from the now following description in connection with the figures. It is shown in:

Fig. 1 a longitudinal section view through a laundry dryer according to the prior art,

Fig. 2 a perspective view of a filter device according to an embodiment of the invention,

Fig. 3 a section through a filter device according to Fig. 2,

Fig. 4 a filter device together with an inlet module in perspective view,

Fig. 5 a perspective section view of a household appliance according to an embodiment of the invention,

Fig. 6 a perspective view of a laundry dryer, Fig. 7 an exploded view of a door of the laundry dryer with a filter device according to an embodiment of the invention,

Fig. 8 an exploded view of a filter device according to an embodiment of the invention, and

Fig. 9 a) and b) a longitudinal section and a perspective view of a casing foot section with a filter device according to an embodiment of the invention.

Way of carrying out the invention

Same or similar elements in the figures are labelled with the same references in all figures.

Fig. 1 shows a conventional laundry dryer according to the condensation principle in a section view, wherein the arrows indicate the air stream of the closed air circuit during operation of the laundry dryer. A drying space 1 shaped as a drum is typically filled with laundry and supplied from behind with hot, dry air. The air absorbs the humidity from the laundry into the drying space 1. The humid, hot air is discharged via the door 2 of the laundry dryer and freed from particles, particularly fluffs, in a filter device 3. The air cleaned in this way is supplied to a heat exchanger 4, inside which it is first cooled in a cooling device 41 in order to release humidity and subsequently heated again by means of a heating device 42. The circuit is closed by supplying the dry air heated in this way back into the drying space 1 by means of a fan 5.

Fig. 2 shows an embodiment of a filter device 3 in a perspective view. In this case a casing 36 contains two filter elements 31 and 37 arranged side by side, with respective wipers 32 and 38. Details of the filter element and wiper are explained for the filter element 31 and the wiper 32. The further filter element 37 and the further wiper 38 are constructed in the same way.

The filter element 31 is circular and has a filter surface 311 as well as a toothed ring 312 at its exterior circumference.

For the purposes of this document the term “filter surface" or "active filter surface" is the surface of the filter element which is equipped with filter material. A wire or a plastic grid with a mesh size adapted to the size of the particles to be discharged may serve as filter material. Other air filters, e.g. air filters made of porous filter material, may also be used.

In the present application the term "filter element" denotes the element comprising the filter material for filtering the supplied air. Preferably the entire "filter element" is manufactured from filter material. For example a circular filter element may consist entirely of filter material. Supporting structures for the filter material may however also be provided. An embodiment in case of which only a partial surface of such a filter element is adapted to be the active filter surface is also included.

In the present application the filter element and particularly its filter surface is preferably "even" in the sense of not curved. Thus, the filter element is arranged in a plane. During operation of the filter device such a filter element is preferably spanned, attached or arranged in another way, such that it has an even shape in the air stream. Curvatures of the filter element which are generated by the air stream are not considered in the sense of the definition, as well as e.g. bridges connected to the filter element for its stabilization, irregular filter material, or the like.

The wiper 32 wipes the filter element 31, and particularly its active filter surface, and frees it in this way from particles separated from the air stream. The wiper 32 is normally in contact with the filter element 31 and is moved over the active filter surface. However, a wiping of filter element surfaces which are not active filter surfaces is also reasonable because particles attached there may also be collected in a fluff deposit which will be described later.

The air stream to be filtered impacts frontally the faces of the filter device 3 in Fig. 2, defined by the wiper 32, 38. For wiping, the filter element 31 and the wiper 32 rotate with respect to one another. In case of a round filter element 31 the filter element 31 may be rotated about a line through its center point. According to Fig. 3 an (exterior) toothed ring 312 of the filter element 31 cooperates with a worm drive 341 as a worm gear, being actuated by an actuator 34, e.g. an electromotor. Only an actuator 34 and a worm drive 341 are necessary for the simultaneous actuation of both filter elements 31 and 37 in case of the filter device 3 according to Fig. 2, because the worm drive 341 interacts with the toothed rings of both filter elements 31 and 37.

It is visible that small volume actuating mechanisms are encouraged by a rotational motion of wiper and filter element relatively to one another, like e.g. the actuation via a worm gear.

In most of the described embodiments the wiper is provided as cleaning device for the filter element. Generally the cleaning device may have, alternatively or additionally to a wiper, air cleaning solutions, water cleaning solutions or other cleaning solutions. The wiper holder may e.g. hold a pipe with nozzles, the nozzles of which are aimed towards the inner face of the filter element and the pipe is impinged by pressurized air for the cleaning process. The filter element may also be freed from particles by means of a rotation of such a cleaning device with respect to the filter element. Preferably, such a pipe is arranged at least at a little distance from the inner face of the filter element. In a similar mechanism a cleaning liquid, e.g. water, may also be supplied to the pipe under pressure instead of pressurized air.

The casing 36 contains a sealing ring 361 for sealing e.g. with respect to an inlet module.

The filter device 3 contains a collecting basin for the particles wiped off the filter element 31. This collecting basin is also called fluff deposit 33. It has a rack shape and it is screwed to the bottom side of the casing 36. The fluff deposit 33 may also be connected to the casing 36 in an easily detachable way, in order to facilitate emptying the fluff deposit 33. The casing 36 contains a fluff gap 362 through which the wiped off particles can fall into the fluff deposit 33.

The wiper 32 is arranged at a fixed location in this case, such that a relative rotation between the wiper 32 and the filter element 31 is generated by rotating the filter element 31. A rotational actuator for the wiper 32 and the filter element 31 may also generate a rotational motion for these elements.

Fig. 3 shows a cross section through an arrangement according to Fig. 2, with an additional section view through a further filter device corresponding to the first filter device 3 and arranged directly in front of the first filter device 3. The elements are again only described for the case of filter element 31 and wiper 32, being identical also for the rest of filter element-wiper-combinations.

This figure clarifies how the worm drive 341 and the toothed rings of the filter elements 31 and 37 interact. The wiper 32 spans radially the filter element 31 with a wiper holder 323. The wiper holder 323 holds a wiper lip 322 which is in contact with the filter surface 311 of the filter element 31. Wiper lips 322 may e.g. be manufactured of rubber or may be formed as bristle elements. The wiper lip has a longitudinal extension of about half of the diameter of the filter element 31. According to this, the entire active filter surface is passed along the wiper lip 312 by rotating the filter element 31 and cleaned by wiping off particles.

The section illustration according to Fig. 3 shows a total of four filter element-wiper-combinations, two of them being arranged side by side, i.e. with filter surfaces arranged in a common plane, two of them being arranged one after the another, i.e. with a two-step cleaning mechanism for which the discharge air of the first filter element-wiper-combination is supplied to the next filter element-wiper-combination.

The dual or multiple arrangement "one after the other" may generally be used in case the air stream shall be cleaned at least two times and a higher air quality shall be reached at the outlet of the filter device. In such an arrangement the filter element or any further filter element may have a same filtering effect as the first filter element, may however also have an increased filtering effect and may have a finer mesh structure than the filter element connected upstream, such that the filter element connected upstream first frees the air from large particles while the subsequent filter element separates smaller particles from the so-filtered air. A dual or multiple arrangement "side by side" may generally be used in case the installation conditions in the household appliance don't allow a single large filter element. Hence, particularly a single, round filter element with a sufficient large filter surface may be hard to arrange in the device, such that two or more filter elements arranged side by side form a more compact filter device instead.

Depending on the requirements, "side by side" and "one after the other" arranged filter elements may be combined in arbitrary ways to form one more filter devices .

Fig. 4 shows in perspective a combination of a filter device 3 and an inlet module 7. A tube 6 is attached to the inlet module 7 via attachment means, in the present construction e.g. via a tube clamp 61, and supplies the air to be filtered to the inlet module 7. The inlet module 7 is connected to the casing of the filter device 3, e.g. via a screw attachment as indicated, and supplies the air to be filtered on to the filter device 3. A cam of the worm drive 341 protrudes out of the filter device 3. A window 71 in the inlet module 7 also allows access to the screwed filter device 3, particularly to its wiper and the filter element.

Fig. 5 shows an exemplary household appliance with a transparent casing 8 for illustrative reasons as a laundry dryer with a drying space 1, a door 2 and a filter device 3. The filter device 3 is supplied with the discharge air from the drying space 1 via a not shown tube.

The filter device 3 is constructed in a modular way with two filter elements at a time arranged side by side in a common casing 36, and two such filter modules arranged one after the other. The filter modules are easily removable and exchangeable. A common rackshaped fluff deposit 33 is arranged below the filter modules and collects the particles deposited by all filter elements. The fluff deposit 33 may by extractable such that discharge of the particles is easy. It may be accessible from the front side of the device, e.g. below the user door.

The filter device 3 is preferably arranged in a device foot 9 of the household appliance. The household appliance is positioned with the device foot 9 on the ground. Preferably the filter device 3 is arranged in the device foot 9 close to the door in order to keep short the length of a tube for air supply.

Fig. 6 shows a laundry dryer in perspective view with a casing 8 and a door 2 for accessing the drying space 1. A device foot 9 has a flap 81 on its front side below the door 2, which enables accessing a filter device 3 consisting of three filter modules. The filter modules are shown in extracted state. They are screwed to one another and have a common fluff deposit 33. The fluff deposit 33 is attached to the filter modules from below and has an opening via which the fluffs can be discharged. Additionally, each filter module has guide grooves 363 corresponding to bridges 91 in the casing foot 9 and simplifying the insertion of the filter device 3 into the device foot 9.

Fig. 7 shows the arrangement of a filter device, e.g. in a door 2 of a household appliance. The wiper 32 with the wiper holder 323 and the wiper lip 322 is attached to the door 2 via a ring 321. The filter element 31 with its round, active filter surfaces 311 and a toothed ring 312 is supported in a rotatable way about the filter surface 311. The spanning of the filter device 3 against a frame 21 of the door 2 is done via multiple rings of which a Teflon ring 24 enables the rotation of the filter element 31 against the frame 21 of the door 2 with low friction. A spring ring 22 presses the filter element 31 outwards against the wiper, such that a contact between the wiper 22, and particularly its wiper lip 322, and the filter surface 311 is created, being advantageous for cleaning. A sealing ring 23 seals the filter device 3. Mounting the filter device 3 into the door 2 of the household appliance is particularly spacesaving and frees mounting space in the device foot. The wiped off fluffs are collected via a not shown fluff deposit arranged in an appropriate way. The filtered air stream is guided on within the device in an appropriate way.

Fig. 8 shows in a partial exploded view a further advantageous embodiment of a filter device 3, here with a single round filter element 31 interacting with a wiper 32 in a casing 36. The casing 36 has furthermore a supplying gap 362 for a further filter element 37. This further filter element 37 is formed as ordinary fluff filter and may be cleaned manually after removing it from the casing 36. Furthermore a fluff deposit 33 is provided.

The casing 36 and the fluff deposit 33 are inserted into a further casing 39 through a flap 391. The further casing 39 contains an actuator 34 for actuating the filter element 31. The filtered air exits the further casing 39 through a rear opening. The air to be filtered is supplied through a not shown opening in the flap 391 of the filter device 3.

It is evident that the air to be filtered is subjected to a two-step cleaning process: first the air is cleaned with the filter element 31 and thereafter it flows through the further filter element 37.

The entire arrangement according to Fig. 8 is also formed as filter module, which may easily be mounted e.g. into the device foot of a household appliance. The fluff deposit 33 may be accessible, removed and emptied via a flap 391 of the further casing 39.

Fig. 9a) shows a filter device 3 similar to the filter device according to Fig. 8 in longitudinal section in a state of being mounted into----- a device foot 9. Fig. 9b) is the corresponding perspective view. The air to be filtered is supplied first to the filter element 31 with attributed wiper 32 via components of the dryer casing 8, before the air filtered in this way is then supplied to the further filter element 37. An exemplary distance between the first and the further filter element 31 and 37 is indicated as 30 mm. This distance is preferably smaller than 100 mm. The wiped off fluffs are accessible via a flap 81 in the dryer casing 8.

The discharge air from the further filter element 37 is supplied to a cooling device 41. An exemplary distance between the filter device 3 and the cooling device 41 is of 40 mm, preferably smaller than 100 mm.

While preferred embodiments of the invention are described in the present application, it is clearly noted that the invention is not limited thereto and may be executed in other ways within the scope of the now following claims. 1 Drying space 2 Door 21 Frame 22 Spring ring 23 Sealing ring 24 Teflon ring 3 Filter device 31 Filter element 311 Filter surface 312 Toothed ring 313 Sealing ring 32 Wiper 321 Ring 322 Wiper lip 323 Wiper holder 33 Fluff deposit 331 Sealing 34 Actuator 341 Worm drive 36 Casing 361 Sealing 362 Fluff deposit 363 Guide groove 37 Further filter element 38 Further wiper 39 Further casing 391 Flap 4 Heat exchanger 41 Cooling device 42 Heating device 5 Fan 6 Tube 61 Tube clamp 7 Inlet module 71 Window 8 Dryer casing 81 Flap 9 Device foot 91 bridge

Claims

Household appliance, with a filter device (3) for separating particles from an air stream, said filter device (3) having a filter element (31) and a cleaning device for cleaning the filter element (31), and wherein the filter device (31) and the cleaning device is arranged pivotally against each other, wherein the filter element (31) is formed flat and circular, characterized in that a gear ring (311) arranged circumferentially on the filter element (31) and a worm wheel forms a worm gear to drive the filter element (31) .

Household appliance according to claim 1, characterized in that the cleaning device is designed as a stripper (32).

Household appliance according to claim 2, characterized in that the stripper (32) is arranged stationary and the filter element (31) is rotatably mounted.

Household appliance according to one of the preceding claims 2 to 3, characterized in that the scrubber (32) has a scrubbing lip (322) having a length extension of at least half the diameter of the filter element (31).

Household appliance according to one of claims 2 to 4, characterized in that the stripper (32) is arranged radially over the filter element (31).

Household appliance according to one of the preceding claims, characterized by a further filter device for separating particles from an air stream with a further filter element and with a further cleaning device for cleaning the additional filter element, which further filter element and which further cleaning device are arranged pivotally against each other .

Household appliance according to claim 6, characterized in that the filter device and the additional filter device are arranged side by side so that the respective filter elements are arranged in the same plane.

Household appliance according to claim 7, characterized in that each filter element has a peripheral ring arranged peripherally on the filter element, which dental rings work together with a common worm as worm gear.

Household appliance according to one of the preceding claims, characterized in that the filter device is arranged in a door of the home appliance.

Household appliance according to one of the preceding claims, characterized in that the filter device (3) is arranged under a drying room (1) in an appliance foot (9) for placing the household appliance on the support.

Household appliance according to one of the preceding claims, characterized in that the filter device (3) is designed as a filter module which can be taken out of the household appliance.

Household appliance according to one of the preceding claims, characterized in that the household appliance is designed for drying clothes and that the filter element is designed as a filler filter.