WO2008145518A1

WO2008145518A1 - Domestic appliance for treating items of laundry, in particular washer dryer

Info

Publication number: WO2008145518A1
Application number: PCT/EP2008/055905
Authority: WO
Inventors: Harald MOSCHÜTZ; Andreas Stolze
Original assignee: BSH Bosch und Siemens Hausgeräte GmbH
Priority date: 2007-05-25
Filing date: 2008-05-14
Publication date: 2008-12-04
Also published as: CN101680156B; CN101680156A; ATE481525T1; DE102007024438A1; EP2155949B1; DE502008001341D1; EP2155949A1

Abstract

The invention relates to a domestic appliance for treating items of laundry with a dryer part (1) which can be cooled by cooling air (K) and comprises a condenser which comprises a hollow body (2) through which damp process air (P) which comprises lint can flow substantially upward from below and though which condensate liquid (22) can flow downward from above, wherein the hollow body (2) has a constriction (24) which is formed so as to prevent condensate liquid (22) running down the inner walls (21) of the hollow body (2) from running down in an unobstructed manner under the action of the process air (P) flowing in the opposite direction by approximately cylindric eddying (23), wherein a lint filter system is formed by means of the interaction between the eddying (23) and the flowing process air (P).

Description

Domestic appliance for the care of laundry items, in particular

washer dryer

The invention relates to a domestic appliance for the care of laundry items, in particular a washer-dryer.

EP 0 636 732 B1 discloses a washing machine equipped with a condenser for drying, which condenser consists of a hollow body through which moist process air can flow substantially from bottom to top and is flushed with tap water for cooling purposes via a switchable valve in the inlet. The inlet is dimensioned for a water flow which is suitable for flushing the hollow body and can be operated intermittently for supplying cooling water.

Furthermore, DE 195 22 307 C2 discloses a washing machine equipped with a condenser for drying, which consists of a hollow body through which moist process air can flow substantially from bottom to top and, for cooling purposes, via a switchable valve in the upper area of the hollow body Inlet is rinsed with tap water. The tap water runs as cooling water partly from the inner walls of the hollow body and is discharged via a lye drain system. The hollow body has in the inlet region of the process air to at least approximately horizontal spoiler edge, which is suitable to keep the run-down cooling water under the action of the counter-flowing process air by almost cylindrical swirling from unrestricted drainage. In addition, lint entrained in the process air stream can thereby also be washed out.

Tumble dryers and also washer dryers tend to pollute the airways due to leaching during prolonged use without maintenance. This leaching can lead to the loss of function of the dryer. This dryer are known in which lint filters are used. As has already been explained in the aforementioned prior art, dryers are also known in which water cooling is provided, it also being possible to filter lint by the cooling water. In the known dryers, however, a large amount of water is needed and it is a considerable maintenance required.

It is an object of the present invention to provide a domestic appliance for the care of items of laundry, in which the lint filtering with a reduced water requirement and the maintenance intensity can be reduced.

This object is achieved by a household appliance for the care of laundry items, which has the features of claim 1.

A domestic appliance for the care of laundry includes a dryer section, which is not water-cooled but air-cooled. This dryer part, which can be cooled by cooling air, comprises a condenser which has a process air which essentially comprises from bottom to top with moist and lint and hollow body through which condensate liquid can flow from top to bottom. The condenser has a constriction narrowing the flow cross-section, which is designed to retain condensate liquid running down on inner walls of the hollow body under the effect of the countercurrent process air by approximately roller-shaped swirling of the condensate liquid, whereby the interaction between the swirling and the flowing Process air is formed a lint filter. By means of such a configured household appliance, an effective filtering out of lint in the process air stream can be achieved and the maintenance effort can be considerably reduced, in particular even completely avoided. In addition, the amount of liquid required to wash out lint can be substantially reduced.

Preferably, the constriction is circumferential and annular. This symmetrical design ensures a particularly effective vortex formation of the condensate liquid and a local increase in the speed of the process air. Due to the annular configuration of the constriction, a particularly intensive contact of the process air with the condensate liquid can be achieved, thereby ensuring particularly effective lint filtering. Preferably, the bottleneck is formed at an input of the capacitor. As a result, it is not necessary to form a constriction inside the condenser. The cross-sectional reduction takes place directly at the entrance of the heat exchanger, where the process air is deflected on the one hand and distributed on the other hand from a round cross-section in the flat heat exchanger tubes. In this case, local flow areas with sufficient flow velocities in the process air virtually occur spontaneously.

The constriction may preferably also be formed in the interior of the condenser, in particular in the hollow body.

The roller-shaped turbulence can be generated permanently during a drying process of the household appliance. This means that a permanent lint filtering is given and the turbulence does not build up alternately and then collapse again.

The countercurrent flows of the condensate liquid and the process air are preferably designed such that equilibrium is established between the condensate liquid flowing from above into the cylindrical turbulence and the condensate liquid flowing down from the cylindrical turbulence. The turbulence thus takes place permanently largely by itself. By establishing a pressure difference across the water vortex, this equilibrium can be generated and maintained.

The height of the roller-shaped turbulence is preferably about 10 mm, which is generated by the pressure difference across the water vortex. This height ensures effective lint filtering.

The cylindrical turbulence has in the equilibrium state between inflow and outflow of condensate liquid amount of between 25 ml and 100 ml, in particular about 50 ml. The amount enclosed in the water vortex should neither be too high nor too low. If the amount is too high, the flow resistance of the hollow body is increased too much and the heat exchanger surface is reduced too much. If the height is too low, the effectiveness of lint filtering will also decrease. The resulting compromise is based on a completely different basis than the one which is to be produced in DE 195 22 307 C2 for optimizing the interaction between the cooling water and the process air.

The constriction preferably has an inner diameter which is between 80% and 95%, in particular about 90%, of the inner diameter which the process air guide, in particular the condenser of the domestic appliance has adjacent to this constriction. As a result, the flow rates and vortex formation can be optimally adjusted.

In the process air guide of the domestic appliance, a liquid collecting device is preferably arranged upstream of the condenser in which liquid can be collected from a preceding laundry care process and which can be introduced into the condenser to form the vortex at the beginning of a subsequent laundry care process. The liquid collection device may be a bag, which in particular has at least one fold of an existing bellows. The water obtained from a preceding washing or drying process, in particular during a spouting or spinning process, can be stored here and entered into the heat exchanger or condenser at the start of the subsequent drying process, in particular when the process air stream is put into operation. As a result, the sufficient and required turbulence for lint filtering can be generated right from the start.

It is particularly preferred if the course of the circulated in the turbulence condensate is dependent on an actively controlled reduction of the counterforce generated by the process air flow. This can be done by changing the flow velocity of the process air and / or the air mass flowing in the process air. For example, for this purpose, the fan, which generates the process air flow, switched slower running or partially completely disabled. The process air flow can thus be reduced not only in its flow velocity and / or its air mass, but also completely deactivated. By such a clocked training of the process air flow can be achieved very quickly and demand-dependent the flow of the circulated condensate liquid. It can be provided that rinsing liquid can be fed into the interior of the hollow body. For this purpose, an external water connection can be provided, via which the rinsing liquid can be conducted into the hollow body. The rinsing liquid may also be the liquid contained in the liquid collecting device.

Preferably, rinsing liquid can be supplied at the beginning of a drying process and / or at the end of a drying process. In the case of the air-cooled drying part, in which liquid cooling is not provided, the amount of condensate liquid may not be sufficient, in particular at the start of drying or at the end of drying, in order to be able to generate a fluid vortex in the region of the constriction. Especially during these phases of the drying process can be advantageously supported by the supply of rinsing fluid vortex formation. By possibly at specific times of the drying process for relatively short periods compared to the duration of a drying process and moreover in very defined and metered amounts of rinsing liquid can be supplied, the supplied required amount of liquid can still be minimized. Also, this freedom of maintenance is not affected.

In particular, it can be provided that the amount of rinsing liquid to be supplied can be supplied additionally or instead as a function of a specific phase of the drying process as a function of a condensate liquid currently present. This can be monitored for example by a suitable sensor.

Preferably, a sensor for monitoring the vortex formation of the liquid is arranged in the region of the constriction, which sensor is connected to a control unit for controlling the rinsing liquid addition. In particular, the sensor may be a temperature sensor or a moisture sensor. It is preferred if this sensor is arranged on the outside of the hollow body in the region of the constriction. The flushing fluid which can be supplied externally via a water connection can also be used to clean the condenser and the entire airways after each drying and also after each wash cycle.

Preferably, the hollow body is formed so that it has on both sides of the constriction an inner diameter which is greater than the inner diameter of the constriction. By this dimensioning, the flow of the process air on the one hand and the vortex formation of the condensate liquid on the other hand can be generated in an optimal manner.

In particular, the household appliance is designed as a washer-dryer.

An embodiment of the invention will be explained in more detail with reference to a schematic drawing. The single figure shows a schematic sectional view of a portion of a drying part of the domestic appliance according to the invention. Form and arrangement of the components are merely exemplary and may be otherwise provided.

The schematic figure shows an air-cooled and thus not water-cooled dryer part 1 of a washer dryer. The dryer part 1 comprises a condenser 2 with a hollow body 2 which is concretely a heat exchanger tube 2 of a plurality of such heat exchanger tubes 2 in the condenser 2. In the hollow body 2, a condensate liquid 22 accumulating during the drying process flows from top to bottom on an inner side 21 in the hollow body 2. In a direction opposite to the flow direction of the condensate liquid 22 and thus from bottom to top flows a process air P, whose flow direction is defined by a blower, not shown, which is coupled to the hollow body 2. On the outside, cooling air K passes the hollow body 2 to remove heat from the process air P and to cause entrained water vapor to condense. Since the inner side 21 is the coolest point in the hollow body 2, this condensation takes place there in the first place. Means for driving and guiding the cooling air K along the hollow body 2 including a fan and a duct system, as known per se, not shown here.

The process air P flows from a supply air opening 26, which simultaneously represents the drain opening for the condensate liquid 22, via a constriction 24 of the hollow body 2 to a fan connection opening 27. In the embodiment shown, the constriction 24 is arranged inside the condenser. It can preferably also be provided that the constriction 24 in the flow direction of the process air P at the supply air opening 26 of the capacitor, in particular at the entrance of the hollow body 2, is formed. The constriction 24 is formed so that it reduces the flow cross-section in the hollow body 2. On both sides of the constriction 24, the inner diameter of the hollow body 2 are larger than the inner diameter d at this constriction 24, where it is important that, considered in the direction of the process air P, the inner diameter of the hollow body 2 expands beyond the constriction 24. Through the constriction 24, a local circulation of the condensate or condensate flowing down 22 and thus a vortex or turbulence 23 is generated. The constriction 24 is formed circumferentially, and the turbulence 23 is also substantially an annular structure.

On an outer side 25 of the hollow body 2, a sensor 3 is arranged in the region of the constriction 24. This may be a temperature sensor 3 or a humidity sensor 3, which is electrically connected to a control unit 4. The control unit 4 is further connected to a valve 5, which is arranged in a supply channel 6. Via the supply channel 6, external rinsing liquid can be conducted into the interior of the hollow body 2. The rinsing liquid can originate from a liquid collecting device 7, which is preferably arranged in the process air guide of the washer-dryer in the flow direction of the process air P in front of the condenser to be flowed through.

The downflowing condensate liquid 22 impinges on the constriction 24 to the process air P accelerated there, whereby parts of the condensate liquid 22 are torn up and swirled above the constriction 24 to form a kind of annular roller.

This accumulates more and more condensate liquid 22 until the weight force generated by the mass of the circulated condensate liquid 22 is greater than that by the

Stream of process air P generated counterforce. The then running over the bottleneck water or the condensate liquid 22 is then in a not shown

Lye drainage system led to a tub.

In particular, however, it is provided that for the defined generation of the flow of the circulated condensate liquid 22 above the constriction 24, the opposing force generated by the process air flow P is changed defined. It can be provided in particular that the fan is made weaker, whereby the process air flow P is changed. The turbulence 23 is substantially permanently formed during the drying process, and a balance is established between the condensate liquid 22 running from above into the turbulence 23 and flowing downwards from the turbulence. In the turbulence is about an amount of 50 ml of condensate liquid 22 included.

During the drying process, external rinsing liquid is supplied via the supply channel 6 only in defined amounts, if no or insufficient vortex formation or turbulence 23 is detected via the sensor 3. Depending on the signal of the sensor 3, the valve 5 is then controlled accordingly via the control unit 4. In particular, in an air-cooled dryer part 1, the phase of the start of the drying process and the end of the drying process with respect to the formation of turbulence 23 solely by the condensate liquid 22 is critical. In particular, in these phases of the drying process can then be provided to supply rinsing liquid defined in terms of time and / or quantity.

This refinement of the domestic appliance makes it possible to provide an air-cooled dryer part, in which the lint filtering is made possible without maintenance and, moreover, considerable water savings can be made possible. The lint filtering can generally be made possible solely by the condensate liquid and, if necessary, at best requires a small additional amount of rinsing liquid.

Claims

claims

1. Domestic appliance for the care of laundry with a by cooling air (K) coolable dryer part (1) comprising a condenser comprising a substantially from bottom to top with moist and lint process air (P) and from top to bottom with condensate liquid ( 22) through-flowable hollow body (2), wherein the condenser has a constriction (24) which is formed on the inner walls (21) of the hollow body (2) running-down condensate liquid (22) under the action of the counter-flowing process air (P) approximately roll-shaped turbulence (23) to preserve the unimpeded flow, wherein by means of the interaction between the turbulence (23) and the flowing process air (P) lint filtering is formed.

2. Domestic appliance according to claim 1, wherein the constriction (24) is circumferential and annular.

3. domestic appliance according to claim 1 or 2, wherein the constriction (24) at an input (26) of the capacitor is formed.

4. Domestic appliance according to claim 1 or 2, wherein the constriction (24) in the interior of the capacitor, in particular in the hollow body (2) is formed.

5. Domestic appliance according to one of the preceding claims, wherein the counterflow of the condensate liquid (22) and the process air (P) are formed so that a balance between the top of the cylindrical vortex (23) inflowing condensate liquid (22) and the condensate liquid (22) flowing down from the cylindrical turbulence (23) is adjusted.

6. domestic appliance according to claim 5, wherein the roller-shaped turbulence (23) during a drying process of the domestic appliance is permanently generated.

7. Domestic appliance according to one of the preceding claims, wherein the height of the roller-shaped turbulence (23) is about 10 mm.

8. Domestic appliance according to one of the preceding claims, wherein the roller-shaped turbulence (23) in the equilibrium state between inflow and outflow of condensate liquid (22) has a liquid amount between 25 ml and 100 ml, in particular about 50 ml.

9. domestic appliance according to one of the preceding claims, wherein the constriction (24) has an inner diameter (d), which is between 80% and 95%, in particular 90%, of the inner diameter, the process air flow of the

Domestic appliance adjacent to this bottleneck (24).

10. Domestic appliance according to one of the preceding claims, wherein in the process air flow of the domestic appliance in the flow direction of the process air (P) in front of the condenser a liquid collecting means (7) is arranged, in which liquid from a previous laundry care process is collectable and which at the beginning of a subsequent Laundry care process in the condenser to form the vortex (23) can be introduced.

11. Domestic appliance according to one of the preceding claims, in which the drain of the condensate liquid (22) from the turbulence (23) is dependent on an actively controlled reduction of the flowing process air (P) against the weight of the condensate liquid (22) generated counterforce.

12. Domestic appliance according to one of the preceding claims, wherein rinsing liquid in the interior of the hollow body (2) can be fed.

13. Domestic appliance according to claim 12, wherein rinsing liquid can be supplied at the beginning of a drying process and / or at the end of a drying process.

14. Domestic appliance according to claim 12 or 13, wherein the supplied amount of the rinsing liquid is dependent on the existing condensate liquid (22).

15. Domestic appliance according to one of the preceding claims, wherein in the region of the constriction (24) a sensor (3) for monitoring the vortex formation of the liquid is arranged, which is connected to a control unit (4) for controlling the Spülflüssigkeitszugabe.

16. Domestic appliance according to one of the preceding claims, wherein on both sides of the constriction (24) of the hollow body (2) is widened to a diameter greater than the constriction (24).

17. Domestic appliance according to one of the preceding claims, which is designed as a washer-dryer.