DE102012223436A1 - Household laundry drying machine with lint filter cleaning device - Google Patents

Abstract

The household laundry drying device 1 has a process air channel 3, a lint filter 9 inserted in the process air channel 3 and a cleaning device 10 for removing lint from the lint filter 9, the household laundry drying device 1 being set up to actuate the cleaning device 10 during a drying process ,

Description

The invention relates to a household laundry drying device, comprising a process air duct, a lint filter inserted in the process air duct and a cleaning device for removing lint from the lint filter.

DE 37 38 033 A1 discloses a condensate trap in a household tumble dryer. Sensors are arranged in the area of a cooling medium inlet and cooling medium outlet. The temperature difference at these heat sensors changes with strong leaching of the plates of the condensate separator. If a threshold value is undershot, an indicator on the tumble dryer is actuated. A user can then remove the lint from the condensate separator after the drying operation.

DE 37 38 031 A1 discloses a method and apparatus for removing lint from a condensate separator formed as a heat exchanger wherein drying air is passed through air ducts and the process exhaust air is directed in the same plane perpendicularly between plate formed channels of the condensate separator and the resulting condensate from the Dried plates and collected in a collection and from there via a riser into a, higher in the dryer and removable condensate collection tank is pumped. Flakes settle on the board surfaces. These are rinsed with at least a portion of the resulting condensate from the plates. For this purpose, designed as a heat exchanger condensate separator is provided with a Wäscheflusenausspülvorrichtung. As a result, the lint can be removed from the formed as a heat exchanger condensate separator without much effort for the operator. It is disclosed that the heat exchanger during operation of the drying process of the laundry constantly in operation, and the Wäscheflusenausspülvorrichtung is operated in the form of a spray device only at the end of the drying process.

DE 10 2008 055 086 A1 relates to a laundry drying apparatus comprising a sieve for sifting out bodies, in particular lint, from a process air duct of the laundry drying apparatus and having a cleaning device for cleaning the sieve, wherein the sieve is arranged obliquely in space at an angle. The method is for cleaning a screen of a clothes drying apparatus by means of a cleaning device for cleaning the screen, wherein the screen is arranged at an angle obliquely in space and a cleaning liquid is passed over the obliquely installed screen.

DE 39 30 727 A1 discloses an arrangement and a method for contamination control and display of a lint filter and / or heat exchanger in a tumble dryer. In a tumble dryer, the degree of contamination of a component can be detected by measuring the differential pressure in a measuring section. An accurate measurement result should be achieved as independent as possible from outside influences. In order to obtain an accurate measurement result independent of external influences, the measuring section, via which the differential pressure is measured, contains the components not at risk of contamination, such as the washing drum and the heating register. The falling differential pressure in this measuring section is a measure of the degree of soiling of a component. The measure arrangement and the measuring method are particularly suitable for household tumble dryer.

From the DE-OS 21 35 932 a pollution degree monitoring of a filter element is known, are connected to the measuring lines of a differential pressure measuring device in the air duct directly in front of and behind the endangered by pollution component, a lint filter.

It is the object of the present invention to provide a more effective laundry drying of a laundry drying apparatus of the type in question.

This object is achieved according to the features of the independent claims. Preferred embodiments are in particular the dependent claims and the following description and attached drawing removable.

The object is achieved by a household laundry drying apparatus comprising a process air duct, a lint filter inserted in the process air duct, and a cleaner for removing lint from the lint filter, the household laundry drying apparatus being adapted to operate the cleaner during a drying process.

Due to the fact that the cleaning device is now actuated not only after a drying process, but also automatically during a drying process, clogging of the lint filter is already suppressed during the drying process. Regular rinsing allows the air output to be maintained at a high level throughout a drying period. This achieves more effective laundry drying. This is particularly advantageous in drying processes with a high amount of lint and / or a high drying time. In addition, borderline cases of device design (eg operation at high Ambient temperature, eg at 35 ° C, be significantly mitigated. This makes the design of device functions much more tolerant. The likelihood of unwanted response of a lint recognition just at the end of life decreases with it, which contributes to a higher customer satisfaction. Due to the constantly high air power also an improvement of the process in terms of energy consumption and a drying time is possible. In addition, a reduction of the noise and a fan wheel shaft power of a process air blower is conceivable by a possible reduction of the starting volume of the process air to be delivered.

The household tumble dryer is particularly a dedicated tumble dryer or a combination device, e.g. a washer dryer.

The household laundry drying apparatus is in particular a recirculating air dryer, that is, it has a closed or circulating process air duct. Lint filters of a circulating air dryer are particularly susceptible to clogging, since unfiltered lint can pass through the circulation in the process air duct to the lint filter again.

In particular, the household laundry drying apparatus has a laundry treatment space connected to the process air duct, in particular a laundry drum, a heater for heating the process air, a blower ("process air blower") for moving the process air in the process air duct, and a condensate water separator for condensing out the process air. The condensate separator is located behind the lint filter in terms of ventilation, so that the lint filter can prevent lint from accumulating on the condensate trap and reducing its condensation effect. In other words, the lint filter may be located in particular between the laundry drum and the condensate separator.

It is a preferred development that the cleaning device is actuated or activated without interrupting a drying function, that is, for example, is operated when the condensate separator, running heating and / or running fan. It is an alternative development that a drying function is interrupted to actuate the cleaning device, so for example, the condensate is not supplied with coolant, the heater is turned off and / or the fan is turned off. The interruption of a drying function is particularly so short that a duration of the drying process or drying program is not or not significantly extended. This is especially true since a higher drying efficiency can even shorten the duration of the drying process or drying program.

It is a preferred development that the household laundry drying device is adapted to operate the cleaning device in addition to the completion of the drying process. This ensures that the lint filter is already cleaned at the beginning of a new drying process. In particular, such a drying of the lint is prevented at the lint filter. This may be part of a drying program.

The lint filter may also be referred to as a lint filter.

It is a preferred embodiment that the cleaning device can be actuated or activated at predetermined time intervals. This embodiment is particularly easy to implement. For example, the household tumble dryer may operate the cleaner at fixed intervals, e.g. every 30 minutes.

It is still a preferred embodiment that the cleaning device can be actuated in dependence on at least one set operating parameter. This allows a more effective drying operation. A set operating parameter may in particular be understood as a preset operating parameter whose initial setting or selected value co-determines the following drying sequence or drying operation.

It is a preferred development that at least one set operating parameter is an operating parameter set by the domestic clothes dryer, e.g. a loading and / or a drying period. For example, with a high loading and / or a high drying time and thus a higher expected amount of lint, the time between two cleaning operations (also referred to below as "cleaning interval") may be shortened. For example, the load may be automatically detected by the household tumble dryer, e.g. by means of a weighing sensor.

It is a further preferred embodiment that the cleaning device can be activated as a function of at least one operating parameter set on the user side. This also allows a more effective drying operation. A user-set operating parameter may include, for example, a drying time, a type of laundry, a drying temperature, etc. For example, when choosing a type of laundry, which is known for a high amount of lint (eg terry or bed linen), the cleaning interval will be shortened.

It is yet another preferred embodiment that the cleaning device can be actuated as a function of at least one sensed operating parameter. A sensed operating parameter may, in particular, be understood as meaning an operating parameter which is sensed during a drying process and is therefore not only predetermined or preset or determined only once before the drying process. A sensed operating parameter may in particular be an operating parameter which is monitored during the drying process. It is a development that the sensed operating parameter is determined by means of at least one sensor or sensor. This embodiment allows a particularly effective drying operation by optimized lint cleaning.

It is a further preferred embodiment that the cleaning device can be actuated as a function of a temperature difference. This is based on the fact that a lint filter which is added reduces a volume flow of the process air moved in the process air duct, as a result of which temperature differences in the domestic tumble dryer can change. In addition to its comparatively low-cost implementation, this embodiment also has the advantage that possibly already existing measuring devices can be used to determine a temperature difference. Such existing measuring devices may be, for example, measuring devices for detecting overheating of the drying device.

It is a further preferred development that a temperature difference can be determined by means of such an already existing measuring device for temperature difference determination and this temperature difference is used both for actuating the cleaning device and for outputting an indication to a user. In particular, the operation of the cleaning device is triggered earlier than the output of the hint. The output of the note indicates to the user an inoperable or potentially harmful condition of the clothes dryer, in particular its possible overheating. The output of the hint may be associated with a power reduction or shutdown of the clothes dryer.

It is a preferred development that the temperature difference is a temperature difference of the process air to two different locations in the process air duct. This may be, for example, a temperature difference in front of and behind the condensate separator. This development allows a particularly accurate inference to a drying efficiency of the laundry drying apparatus and thus a determination at which time an operation of the cleaning device is particularly useful.

It is an additional or alternative preferred development that the cleaning device is operable in response to a (sensed) temperature, e.g. an absolute temperature.

It is also a preferred embodiment that the cleaning device is actuated in response to a pressure difference. The pressure difference is directly dependent on an air permeability of the lint filter and thus its clogging by fluff. The pressure difference can be applied directly to the lint filter, e.g. be sensed immediately before and behind the lint filter, or at another measuring section in the process air duct.

It is a preferred development that the household laundry drying device has a heat pump ("heat pump dryer"). It is still a development that the heat pump is a compressor heat pump, the structure is basically well known and typically has as a drive a compressor or compressor and further comprises a condenser or condenser, an evaporator and a relaxation device, which are interconnected in a coolant circuit , The evaporator can be used in particular as a condensate for the process air at the same time, and the condenser as a heater for the process air. However, other types of heat pumps are also usable, e.g. a Stirling heat pump or a Vuilleumier heat pump.

It is a preferred embodiment of the fact that the cleaning device can be activated as a function of at least one operating parameter of the heat pump. It is exploited that a change in the heat distribution and the heat level in the process air duct also changes operating parameters of the heat pump, e.g. a temperature of the circulating in the heat pump working fluid or coolant, a temperature of the drive and / or a temperature difference at one or more components of the heat pump, in particular to the evaporator.

It is still a preferred embodiment that the operating parameter comprises a presence of a clocking of a drive of the heat pump. Typically, the drive is operated continuously, which allows a particularly high efficiency. However, the drive may, for example, also be operated clocked when its temperature or a temperature of the coolant of the heat pump exceeds a threshold value ("limit temperature"). This may especially occur at high ambient temperatures, which hinder heat removal from the laundry dryer. The clocking reduces the work put into the heat pump so that it can not heat up or even cool down. However, with the clocking also an efficiency reduction of the drying is connected. By operating the cleaning device, the process air can be better circulated, whereby the heat in the heat pump is better dissipated. This, in turn, allows the heat pump to operate continuously more quickly.

The fact that the cleaning device can be activated as a function of at least one set operating parameter may include in particular the case that a value of this operating parameter reaches, exceeds or falls below a threshold value ("activation threshold value"). It may also include the case that a state or status of the operating parameter changes, for example, between the states "on" and "off" changes. This may be e.g. occur when a drive of a heat pump changes from a continuous operation ("timing off") to a pulsed operation ("timing on").

It is also a preferred embodiment that the cleaning device is a rinsing device for rinsing the lint filter. For rinsing in particular condensed water may be used. However, for example, a cleaning device based on compressed air as a cleaning medium or the like is, for example. conceivable.

It is a preferred development that the cleaning device can be activated for a predetermined period of time. Alternatively, the cleaning device may be activatable for a variable period of time, e.g. depending on at least one operating parameter.

In the following description and with reference to the figures of the accompanying drawing, the invention will be described schematically with reference to an embodiment schematically. Show it:

1 a sketch of a household laundry drying machine in the form of a tumble dryer; and

2 a profile of an air flow or a process air volume flow over a drying time of the clothes dryer 1 , each in percent

1 shows a sketch of a household laundry dryer in the form of a tumble dryer 1 , The laundry dryer 1 is a front loader with a rotating laundry drum 2 as a laundry treatment room. The laundry drum 2 is pneumatically or air-technically on both sides of a circulating process air duct 3 connected. The process air duct 3 serves for the closed guidance of process air P from and to the laundry drum 2 , On or in the air intake duct 3 is also a process air blower 4 for conveying or moving the process air P available.

During a drying operation of the clothes dryer 1 is by the blower 4 First, dry-warm process air P through the process air duct 3 in the laundry drum 2 pressed. When flowing through the laundry drum 2 the process air P absorbs moisture from laundry W located therein. Behind the laundry drum 2 There is a condensate separator for cooling and condense the process air P in the form of an evaporator 5 a heat pump 5 - 8th , This is the process air duct 3 or the heat-moist process air P heat removed therefrom and onto the evaporator 5 transfer. The heat pump 5 - 8th Further, in basically known manner, in a refrigeration cycle connected in series, a compressor or compressor 6 , a condenser or condenser 7 , and a relaxation device 8th , eg in the form of an expansion valve. The condenser 7 is with the process air duct 3 thermally coupled and used to heat the previously condensed process air P before re-introduction into the laundry drum 2 , The compressor 6 serves as a drive for generating a heat flow from the evaporator 5 to the liquefier 7 , In this way, cooling and heating of the process air P is achieved in a particularly energy-saving manner.

In the flow direction of the process air P after the laundry drum 2 and in front of the condensate separator / evaporator 5 is a lint filter 9 in the process air duct 3 introduced, which at least a significant portion of entrained by the laundry W fluff (including hair, etc.) filters out of the process air. The lint filter 9 continues to increase as the drying time progresses. The strength of the addition depends on the conditions of the drying, for example on a load, a type of laundry, an age of the laundry W, etc. Especially in terry or bed linen, it quickly comes to a strong addition. This addition of the screen represents a resistance in the airways, which leads to a lower air flow. As a result, the efficiency and effectiveness of the tumble dryer deteriorate 1 , This in turn increases a drying time and energy consumption significantly.

For cleaning the lint filter 9 Of the lint is a cleaning device in the form of a purging device 10 available, which rinsing liquid (eg condensation) over the lint filter 9 passes. The rinsing fluid tears the lint and cleans the lint filter 9 , The rinsing device 10 is from a central controller 11 operable, in particular selectively activated and deactivated, even during a drying process or drying operation.

In particular, likes the tumble dryer 1 the rinsing device 10 as a function of a temperature difference of the process air P before and after the condensate / evaporator 5 as an operating parameter of the tumble dryer 1 actuate. To determine this temperature difference are two temperature sensors 12 or temperature sensors in front of or behind the condensate separator / evaporator 5 arranged without leaving another functional element of the tumble dryer 1 in between. The of the temperature sensors 12 sensed measured values reach the control device via electrical lines indicated by dotted lines 11 where they are further processed, in particular differentiated from each other. The control device 11 can now the purging device 10 when the temperature difference or a value derived therefrom reaches, exceeds or falls below an associated threshold depending on whether exceeding or falling below an undesirable degree of clogging of the lint filter 9 represents.

Alternatively or additionally, the tumble dryer likes 1 the rinsing device 10 as a function of a pressure difference of the process air P in front of and behind the lint filter 9 actuate. The clothes dryer likes this 1 appropriately arranged pressure sensors 13 and react to the pressure difference in particular analogous to the temperature difference, for example by actuation of the purging device 10 when the pressure difference or a value derived therefrom reaches, exceeds or falls below an associated threshold value.

Alternatively or additionally, the tumble dryer likes 1 the rinsing device 10 depending on a temperature of a in the cooling circuit of the heat pump 5 - 8th operate circulating refrigerant, in particular with reaching or exceeding an associated threshold. The temperature of the refrigerant may be, for example, by means of a temperature sensor 14 be felt.

Alternatively or additionally, the tumble dryer likes 1 the rinsing device 10 depending on a state change during operation of the compressor 6 Press, namely when the compressor 6 is switched from a continuous operation in a clocked operation or should be. This may for example be the case when a temperature of the refrigerant or the compressor 6 gets too high.

2 shows as a plot of air flow L or a process air volume flow of the process air P in the process air duct 3 over a drying time t of the tumble dryer 1 a course without intermediate actuation of the flushing device 10 (dashed line K1) and with intermittent actuation of the purging device 10 (dash-dotted line K2).

While the air capacity L without intermediate operation of the flushing 10 decreases continuously and decreases particularly strongly towards the end of the drying time t, the air power L increases due to the intermittent actuation of the flushing device 10 as can be seen by the sudden increase A of the air flow L. In this example, the purging device is 10 has been operated twice, whereby a drop in the air flow L can be limited to less than half of the drop in the air flow L without flushing. In addition, the absolute drying time t extended without intermittent actuation of the purging device 10 considerably due to the poorer drying efficiency.

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

Thus, after the drying process, a final actuation of the rinsing device may be carried out in order to clean the lint filter for a next drying cycle.

LIST OF REFERENCE NUMBERS

1

 clothes dryer

2

 washing drum

3

 Process air duct

4

 Process air fan

5

 Evaporator

6

 compressor

7

 condenser

8th

 expansion device

9

 lint filter

10

 flushing

11

 control device

12

 Temperature probes

13

 pressure sensor

14

 Temperature probes

A

 Increase in air output

P

 process air

L

 air output

W

 Laundry

t

 drying time

K1

 Course of the air flow without intermediate operation of the flushing device

K2

 Course of the air power with intermittent actuation of the flushing device

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 3738033 A1 [0002]
• DE 3738031 A1 [0003]
• DE 102008055086 A1 [0004]
• DE 3930727 A1 [0005]
• DE 2135932A [0006]

Claims (10)

Household laundry drying machine ( 1 ), comprising - a process air channel ( 3 ), - one in the process air channel ( 3 ) lint filter ( 9 ) and - a cleaning device ( 10 ) for removing lint from the lint filter ( 9 ), characterized in that - the household laundry drying device ( 1 ) is adapted to the cleaning device ( 10 ) during a drying process. Household laundry drying machine ( 1 ) according to claim 1, characterized in that the cleaning device ( 10 ) is operable at predetermined time intervals. Household laundry drying machine ( 1 ) according to one of the preceding claims, characterized in that the cleaning device ( 10 ) can be actuated as a function of at least one set operating parameter. Household laundry drying machine ( 1 ) according to claim 3, characterized in that the cleaning device ( 10 ) can be actuated as a function of at least one operating parameter set by the user. Household laundry drying machine ( 1 ) according to one of the preceding claims, characterized in that the cleaning device ( 10 ) can be actuated as a function of at least one sensed operating parameter. Household laundry drying machine ( 1 ) according to claim 5, characterized in that the cleaning device ( 10 ) Is actuated in response to a temperature difference. Household laundry drying machine ( 1 ) according to one of claims 5 or 6, characterized in that the cleaning device ( 10 ) is actuated in response to a pressure difference. Household laundry drying machine ( 1 ) according to one of the preceding claims, characterized in that the household laundry drying device ( 1 ) a heat pump ( 5 - 8th ) and the cleaning device ( 10 ) as a function of at least one operating parameter of the heat pump ( 5 - 8th ) is activated. Household laundry drying machine ( 1 ) according to claim 8, characterized in that the operating parameter is a presence of a clocking of a drive ( 6 ) of the heat pump ( 5 - 8th ). Household laundry drying machine ( 1 ) According to any one of the preceding claims, characterized in that the cleaning device ( 10 ) a rinsing device for rinsing the lint filter ( 9 ).

Images