EP2756128B1 - Laundry dryer having a temperature-activated air-flow blocking unit - Google Patents

Description

The present invention relates to a tumble dryer, in particular household tumble dryer, comprising a drum intended for drying laundry, which is provided with at least one air duct for the air supply and / or the air discharge, which air duct can be closed by means of a temperature-activated Luftstromblockiereinheit.

Such a dryer is apparent from the DE 10 2007 061 521 A1 , There is a clothes dryer described, which is equipped with a fire extinguisher. This fire-extinguishing device may comprise a valve which is arranged in an air duct for conveying an air flow through a laundry drum, which valve is activatable upon release of the fire-extinguishing device for closing the air duct.

In tumble dryers, it can happen again and again that certain small parts, such as lint or small plastic parts, collect and deposit in the drum. When reaching a certain temperature, these parts may be set on fire. This must be prevented. In some states, such test methods are already in force or are scheduled to come into force in the near future to prove that fire is not allowed to escape from the tumble dryer. In the USA, for example, from 2013 it will be checked that a cloth placed over the tumble dryer should not ignite during the test.

The manufacturers of tumble driers are therefore anxious to offer tumble dryer, where the fire inside the tumble dryer can be actively extinguished, or where at least a leakage of the fire can be prevented to the outside. For this purpose, it is known to actively combat the fire by extinction by means of water or other chemicals, after the deletion has been triggered by a temperature sensor. However, such a solution usually requires a functioning power supply for the operation of the temperature sensor and possibly other facilities. Alternatively, a passive control of the fire is possible by no longer easily burning plastic parts are used, but only fire-resistant plastics or metals. However, this is only possible at the cost of increased production costs.

The present invention has for its object to provide a tumble dryer, such as in particular a household tumble dryer, in which an optionally resulting in the drum fire can not escape from the drum and is automatically deleted as possible.

This object is achieved with a tumble dryer according to independent claim. Advantageous developments of the invention are the subject of the dependent claims, the following description and accompanying drawings.

A tumble dryer according to the invention comprises a drum intended to receive laundry to be dried, which is provided with at least one air line for the air supply, the air discharge or both. Usually this is an air supply line for supplying warm, dry air into the drum and a discharge line for draining humidified and cooled air present, the sake of brevity, collectively referred to as "air lines". Of course, several such air lines can be provided.

The tumble dryer according to the invention is characterized in that the air duct can be closed by means of a temperature-activated Luftstromblockiereinheit containing an expansion material that expands so much at a temperature as caused by an emergent or emerging fire that the closure of the air line is effected. By "expansion material" is here to be understood a substance whose expansion above a certain temperature - the thermal expansion by no means must be linearly correlated with the temperature, but can only be used from reaching a certain expansion temperature - is so great that it is a closure of the Air duct can cause. For example, since flames in the drum caused by cotton fluff, wool fluff or small plastic parts can easily reach temperatures of 500 ° C to 800 ° C and above, it is sufficient if the expansion material undergoes longitudinal expansion and / or volume expansion at a temperature below the aforementioned temperature range, for example at 350 ° C to 450 ° C. This inventive solution of the above problem brings Among other things, the advantage that it is much cheaper than active fire extinguishing systems for drum fire fighting. In addition, this solution is completely independent of the power supply of the tumble dryer, as it represents an exclusively "mechanical" solution without the need for connection to a power supply.

According to an advantageous development of the invention, the tumble dryer is characterized in that the air flow blocking unit has a cavity, which is part of the air duct and in which the expansion material is located, which closes the air duct at the temperature that can be caused by a fire by expanding in a defined way, or in other words enlarging its volume. In this way, the air flow blocking unit can close the air duct in a direct manner, without the aid of its own mechanical or electrical device, in a fire. Thus, no separate mechanical actuation for the air flow blocking unit, in particular no electrical power connection for their operation, is required.

Preferably, the expansion material in the air duct, the cross section completely filling, arranged and thereby designed so that it has through holes - below the temperature range at which it expands its volume -, wherein the through holes are dimensioned so that they are at a volume expansion of the expansion material, as it occurs at a temperature that arises in the event of a fire, are closed. By closing these through holes thus the air line is closed. This embodiment is structurally simple to manufacture and works very reliable without further intervention from the outside; it thus closes the air line very reliably and safely only at the temperature caused by a fire.

According to a further advantageous embodiment of the tumble dryer according to the invention, the expansion material in the air flow blocking is arranged so that it serves as an actuator for a closure device for closing the air duct, as soon as it expands its length and / or volume upon reaching a temperature, such as by a fire is caused. The expansion material can also be used in this embodiment as a triggering device or as a trigger for a closure device for closing the air line are called. According to an advantageous development of the invention, the air flow blocking unit has a container having the expansion material and a locking device for locking the closure device. The closure device is held locked as long as the expansion material has not yet expanded, and the locking takes place in a (first) position in which the air line is open. In other words, the air line remains open as long as the expansion material has not yet expanded and thus the closure device has not yet unlocked. The unlocking of the closure device thus takes place only when the expansion material expands, in which case the closure device closes the air line.

According to an advantageous development of this embodiment, the closure device has a first plate with first air passages and a second plate with second air passages, wherein the second plate is movable relative to the first plate, in particular rotatably arranged. The arrangement is such that the second air passages can be moved by an actuator from a first position in which they have a fluid connection to the first air passages, in a second position in which they have no fluid connection to the first air passages. By the movement of the second air passages in the second position thus the air line is closed and therefore prevents the escape of the fire from the drum via the air line. Also, this embodiment of the invention does not require any mechanical influence from the outside and also no electrical power connection to prevent its emergence from the drum when a fire occurs, but is triggered and activated solely by the corresponding increase in temperature. It is advantageous if the actuating device in this case has a spring which acts on the second plate in its first position in the direction of the second position. In this arrangement causes the expansion material as a blocking device which prevents movement of the second plate, as long as the expansion material has not yet expanded, and allows a spring-induced movement of the second plate with the second air passages or releases when the Expanded expansion material far enough and thus cleared the way for the movement of the second plate.

For the reliability of the automatic activation as well as for the extent of the effect which causes the expansion of the expansion material, it is advantageous if the expansion material expands by a factor which is at least 100%, preferably at least 200%. In other words, in this case, the expansion material at a temperature, as is caused in a fire, a thickness which is at least twice, preferably at least three times, its thickness at room temperature.

A simple and inexpensive embodiment of the present invention is possible in that a fabric, a felt, a foamed material or a similar material is used as the expansion material, wherein this material or material is preferably formed from ceramic fibers, which in turn also at high temperatures are not sensitive to fire and thus do not ignite themselves.

• "Expanding Felt 607" von Thermal Ceramics; dieser Stoff dehnt sich bei Auftreten eines Feuers auf mindestens dreifache Dicke aus, er ist aus Erdalkali-Silicat-Fasern hergestellt und enthält eine kleine Menge an organischen Bindemitteln;
• "Palusol" von BASF; dieser Stoff enthält hydriertes Natriumsilicat mit einer kleinen Menge organischen Bindemittels und ist vorzugsweise auf beiden Seiten mit Epoxidharz beschichtet. Ab etwa 100°C beginnt das hydrierte Natriumsilicat, schnell Wasser zu verlieren und sich rapide auszudehnen;
• "FyreWrap XFP Expanding Paper" von Unifrax, USA; dieses Material ist aus einer Zusammensetzung aus feuerbeständigen keramischen Aluminiumoxid-Siliciumoxid-Fasern, nicht expandiertem Vermiculit und einem organischen Bindemittel gebildet. Dieses Material kann als flexible, quellende Matte hergestellt werden, die sich bei etwa 325 °C auf etwa dreifache Dicke vergrößert. Außerdem widersteht dieses Material Temperaturen bis zu etwa 1260 °C.

As expansion material, the following can be used with advantage, but only as an example, substances:

• "Expanding Felt 607" by Thermal Ceramics; this material expands to at least three times its thickness when a fire occurs, it is made from alkaline earth silicate fibers and contains a small amount of organic binders;
• "Palusol" from BASF; this material contains hydrogenated sodium silicate with a small amount of organic binder and is preferably coated on both sides with epoxy resin. From about 100 ° C, the hydrogenated sodium silicate begins to lose water rapidly and to expand rapidly;
• "FyreWrap XFP Expanding Paper" by Unifrax, USA; this material is formed from a composition of fire-resistant ceramic alumina-silica fibers, unexpanded vermiculite and an organic binder. This material can be made as a flexible, swelling mat which increases to about three times the thickness at about 325 ° C. In addition, this material withstands temperatures up to about 1260 ° C.

According to a further advantageous embodiment of the invention, the drum of the tumble dryer comprises an air inlet, which is designed so that the air flow blocking unit can be arranged in the air inlet. Alternatively or additionally, the drum is advantageously designed such that it has a bearing plate in which this or an additional air flow blocking unit can be arranged, this air flow blocking unit then being arranged in the region of the air outlet of the drum.

Fig. 1

in perspektivischer Ansicht eine erste vorteilhafte Ausführungsform des Wäschetrockners;

Fig. 2

eine Schnittansicht einer Luftstromblockiereinheit der ersten Ausführungsform;

Fig. 3

eine Schnittansicht einer Variante der Luftstromblockiereinheit der ersten Ausführungsform;

Fig. 4

in Vorderansicht einen Lufteinlass einer Trommel eines Wäschetrockners;

Fig. 5

in perspektivischer Darstellung eine Luftstromblockiereinheit einer zweiten vorteilhaften Ausführungsform des Wäschetrockners mit offener Luftleitung;

Fig. 6

in perspektivischer Darstellung die Luftstromblockiereinheit gemäß Fig. 5 mit verriegelter Verschlussvorrichtung für die Luftleitung mit noch nicht ausgedehntem Expansionsmaterial;

Fig. 7

in perspektivischer Darstellung die Luftstromblockiereinheit gemäß Fig. 5 mit entriegelter Verschlussvorrichtung für die Luftleitung mit ausgedehntem Expansionsmaterial;

Fig. 8

in perspektivischer Darstellung eine Luftstromblockiereinheit gemäß der zweiten Ausführungsform mit entriegelter Verschlussvorrichtung und geschlossener Luftleitung; und

Fig. 9

in perspektivischer Seitenansicht die entriegelte Verschlussvorrichtung für die Luftleitung.

Further advantages, features and features of the invention will become apparent from the following description of advantageous embodiments, which are illustrated in the figures of the accompanying drawings. Show it:

Fig. 1

in a perspective view of a first advantageous embodiment of the tumble dryer;

Fig. 2

a sectional view of an air flow blocking unit of the first embodiment;

Fig. 3

a sectional view of a variant of the air flow blocking unit of the first embodiment;

Fig. 4

in front view, an air inlet of a drum of a tumble dryer;

Fig. 5

a perspective view of an air flow blocking unit of a second advantageous embodiment of the tumble dryer with open air duct;

Fig. 6

in a perspective view of the air flow blocking unit according to Fig. 5 with locked closure device for the air duct with expansion material not yet expanded;

Fig. 7

in a perspective view of the air flow blocking unit according to Fig. 5 with unlocked closure device for the air duct with expanded expansion material;

Fig. 8

a perspective view of an air flow blocking unit according to the second embodiment with unlocked closure device and closed air line; and

Fig. 9

in a perspective side view of the unlocked closure device for the air line.

Fig. 1 schematically shows in perspective view obliquely from above a drum 20 of a clothes dryer 10. On the side shown here, an air inlet 22 is provided in the form of a perforated disc through which air can flow into the drum 20. A detail view of this air inlet 22 is in Fig. 4 shown in front view. From the Fig. 4 It can be seen in detail that the air inlet 22 comprises a plurality of small holes 23 through which air can flow from the air duct 30, which is only schematically indicated here, into the drum 20. The air inlet 22 is in this case arranged in a housing, not shown, into which the air line 30 opens and in which the air inlet 22 is inserted airtight.

From the air inlet 22 from air can flow through the drum 20 and passes through an only schematically indicated air outlet 26, which is provided in a bearing plate 24, out of the drum 20 and leaves the tumble dryer 10 via an air duct 40 again via an air flow, which is indicated by an arrow A. In the bearing plate 24, an air flow blocking unit 50 is arranged, of which in Fig. 2 and Fig. 3 two variants are shown. FIGS. 2 and 3 12 show sections through the two variants of the airflow blocking unit 50 along a plane containing the axis of the drum 20.

In Fig. 2 It can be seen that in a cavity 32 which is located in the air outlet 26 in the bearing plate 24, an expansion material 70 is arranged. According to Fig. 2 The expansion material 70 occupies only a small portion of the cavity 32 - in this embodiment, less than half - so that air can flow well through the air outlet 26 through the air outlet, which is in Fig. 2 is symbolically represented by an arrow B. The expansion material 70 is designed so that when it reaches a certain temperature, as it is caused by the emergence of a fire, its width or thickness or its volume expands so much that it occupies the entire cavity 32 and possibly between the expansion material 70 and the cavity 32 existing edge gaps are fired by itself. This situation is in Fig. 2 shown schematically by dashed lines. Out Fig. 2 Namely, it can be seen that the volume of the expanded expansion material 70 is considerably larger than in the unexpanded situation. As a result, the air flow through the air outlet 26 is very reliably blocked.

As an alternative to the above-described embodiment of the expansion material 70, the expansion material 70 may also be provided with through-holes 72 and / or configured such that it is smaller in thickness and / or diameter than the cavity 32 in which it is located, that the expansion material 70 in the cavity 32 - possibly additionally or alternatively by the flow through the through holes 72 - can be easily flowed around or flowed through by the air flow and this does not prevent or at least not substantially at the outlet through the air outlet 26. This is schematically illustrated by arrows C, which designate partial air streams. It can be seen that the expansion material 70 in the cavity 32 upon the occurrence of a fire due to the expansion caused thereby the escape of air from the air outlet 26 automatically (ie automatically) prevents it by its thickness and / or volume increase, the air line 30 and 40, whose component is the cavity 32 and the air outlet 26, closes. The expanded state in which the through holes 72 are closed is in FIG Fig. 2 shown in dashed lines. Thus, in both variants of this advantageous first embodiment, the expansion material 70 acts directly through its increase in thickness or volume.

In the Fig. 5 to 9 an airflow blocking unit 60 according to a second embodiment of the tumble dryer 10 is shown. This Luftstromblockiereinheit 60 is in an air line - ie a conduit for air supply and / or for the air discharge - installed, which is not shown in the drawing.

According to Fig. 5 the airflow blocking unit 60 comprises a first, here shown circular, plate 67, which is arranged stationarily with respect to the tumble dryer 10. Adjacent to the first plate 67, a second plate 68, which is also shown here circular, arranged, which in turn is rotatably arranged with respect to the first plate 67. The rotation of the second plate 67 takes place about its center axis perpendicular to the surface. The two plates 67 and 68 respectively have air passage holes 67a and 68a, which are in the in Fig. 5 shown position - which is here referred to as the first position of the second plate 68 - are aligned and thus allow an air passage perpendicular to the surfaces of the two plates 67, 68 due to the fluid connection thus produced. In order to hold the two plates 67, 68 in this position relative to one another, ie the second plate 68 in its first position, a locking device 66 is provided. The locking device 66 comprises a bolt guide housing 61, in which a parallel to the axis of the plates 67, 68 displaceable stop pin 64 is arranged. An angled abutment plate 63 fixedly connected to the second plate 68 (see also FIG Fig. 9 ) is configured so that it comprises a contact portion 63 a, which abuts in the first position of the second plate 68 on the displaceable stop pin 64. Since an actuator 69 is provided, which is designed here as a spring which acts on the abutment portion 63 a so that it is pressed against the stop pin 64, thereby the second plate 68 is fixed relative to the first plate 67. In this position, the actuator 69 also assumes the function of a locking device. From the bolt guide housing 61 and the stopper bolt away extends a here cylindrically illustrated container 62, whose function and configuration will be explained below. In Fig. 5 an arrow D represents the plates 67, 68 passing air flow symbolically.

In Fig. 6 the container 62, the pin guide housing 61 and the displaceable stop pin 64 are shown cut open. In the container 62 is an expansion material 70 which is expanding felt, expanding fabric or a corresponding expanding fibrous material. Instead, the expansion material could also be trapped water, another fluid or a solid that increases its volume or its length or thickness strong enough under heat to perform the function as a triggering device for closing the air duct. As seen from the presentation Fig. 6 As can be seen, the expansion material 70 occupies only the space provided by the container 62.

As soon as a temperature, such as that caused by a fire or a fire, is reached in or on the plates 67, 68 and thus on the container 62, the expansion material 70 expands, thereby pushing the displaceable stop pin 64 away from the container the second plate 68 until the stopper bolt 64 is close to or in abutment with the second plate 68. This situation is in Fig. 9 shown here, for clarity, the bolt guide housing 61 is not shown in the region of the second plate 68 in order to better represent the displaced to the second plate 68 stop pin 64 can. The expansion of the expansion material 70 is in Fig. 7 symbolically indicated by an arrow E. Like also out Fig. 9 As can be seen, the abutment plate 63 is designed such that it has a recess 63b between the abutment section 63a and the second plate 68, which is configured in this way is that the abutment plate 63 and its abutment portion 63a in the in Fig. 9 shown position of the stop pin 64 is no longer applied to the stop pin 64, but let the stopper bolt 64 pass. Once the abutment portion 63a is no longer abutting against the stopper bolt 64, the pressing force of the abutment plate 63 acting as spring actuator 69 causes the second plate 68 to rotate to a second position, as shown in FIG Fig. 8 in the counterclockwise direction, which is represented by an arrow F. Once the second plate 68 has rotated far enough, the air passage holes 67a of the first plate 67 are no longer in alignment with the air passage holes 68a of the second plate 68, thereby blocking the flow of air through the plates 67, 68. The blocked airflow is in Fig. 8 symbolically represented by a circle G. The plates 67, 68 thus form a closure mechanism 65.

In the second embodiment of the tumble dryer, therefore, the air line can be closed indirectly by the increase in volume or length of the expansion material 70. In other words, the expansion material 70 serves as a trigger for the closure mechanism 65 comprising the plates 67, 68.

Of course, the invention described above is not limited to the two embodiments described in detail. The various variants of the temperature-activated airflow blocking unit described above can be used both in condensation dryers and in exhaust air dryers and each ensure a reliable and automatically acting, outside no influence requiring closure of the air duct or the air ducts in the event of a fire. Since no connection to the power grid or the provision of a battery, etc., is required for operation or maintenance of the operational readiness of the air flow blocking unit, the reliability of the air flow blocking unit is also very high. It should be noted that features of the invention described in relation to individual embodiments, such as the design and arrangement of the two plates or the cavity for receiving the expansion material and their dimensions and the materials used, may also be present individually or cumulatively in other embodiments, unless otherwise stated or prohibited by itself for technical reasons.

LIST OF REFERENCE NUMBERS

10

clothes dryer

20

drum

22

air intake

23

Central hole

24

end shield

26

air outlet

30

air line

32

cavity

40

air line

50

Air flow blocking unit

60

Air flow blocking unit

61

Bolt guide housing

62

container

63

bearing plate

63a

contact section

63b

recess

64

displaceable stop pin

65

closure device

66

locking device

67

first plate

67a

Air through hole

68

second plate

68a

Air through hole

69

Actuator / spring

70

expansion material

A

airflow

B

airflow

C

Partial airflows

D

airflow

e

expansion

F

rotation

G

interrupted airflow

Claims (10)

1. Laundry dryer (10), in particular a domestic laundry dryer, comprising a drum (20) intended for laundry to be dried, which is provided with at least one air line (30; 40) for supplying air and/or discharging air, wherein said air line (30; 40) can be closed by means of a temperature-activated air-flow blocking unit (50; 60), characterised in that the air-flow blocking unit (50; 60) contains an expansion material (70), that expands at a temperature caused by a fire to such an extent that the air line (30; 40) is closed thereby.
2. Laundry dryer (10) according to claim 1, characterised in that the air-flow blocking unit (50) comprises a hollow space (32) which is part of the air line (30) and in which the expansion material (70) is arranged, which closes the air line (30; 40) by volume expansion at the temperature caused by a fire.
3. Laundry dryer (10) according to claim 2, characterised in that, while it has not yet undergone volume expansion, the expansion material (70) has through-holes (72), which are closed on volume expansion as a result of the temperature caused by a fire, thus causing the air line (30) to be closed.
4. Laundry dryer (10) according to claim 1, characterised in that the expansion material (70) is arranged in the air-flow blocking unit (60) such that, with the linear and/or volume expansion it undergoes at the temperature caused by a fire, it serves as an actuating device (69) for a closing device (65) for closing the air line (30; 40).
5. Laundry dryer (10) according to claim 4, characterised in that the air-flow blocking unit (60) comprises a container (62), in which the expansion material (70) is arranged, and a locking device (66) for locking the closing device (65) for as long as the expansion material (70) has not yet undergone any expansion, in a first position in which the air line (40) is open.
6. Laundry dryer (10) according to claim 4 or 5, characterised in that the closing device (65) comprises a first plate (67) with first air passages (67a) and a second plate (68) with second air passages (68a) arranged movably, preferably rotatably, relative to the first plate (67) adjacent to the first plate (67), wherein the second air passages (68a) can be moved by the actuating device (69) out of a first position, in which they have a fluid connection to the first air passages (67a), into a second position in which they do not have a fluid connection to the first air passages (67a) and hence the air line (40) is closed.
7. Laundry dryer (10) according to claim 6, characterised in that the actuating device (69) comprises a spring which strikes the second plate (68) in its first position to move it into the second position.
8. Laundry dryer (10) according to any of the preceding claims, characterised in that, at the temperature caused by a fire, the thickness of the expansion material (70) is at least twice, preferably at least three times, the thickness at room temperature.
9. Laundry dryer (10) according to any of the preceding claims, characterised in that the expansion material (70) is a fabric, felt or similar material, in particular one made of ceramic fibres.
10. Laundry dryer (10) according to any of the preceding claims, characterised in that the drum (20) comprises:

    an air inlet (22), in which the air-flow blocking unit (50; 60) is arranged, and/or

    a bearing shield, (24) in which the air-flow blocking unit (50; 60) is arranged.

Images