EP3117036B1 - Dryer with flushing device and lint receptacle, and method for operating same - Google Patents

Description

The invention relates to a dryer with a drying chamber for items to be dried, a process air duct in which a blower for the transport of process air, a heat sink, a heat source and a lint filter, a control unit, a liquid sensor, a flushing device and a collecting device for condensate and / or lint, wherein the catcher is configured as a lint depot with a filter which is permeable to an aqueous liquid but retains lint and a trough for receiving the liquid passed through the filter and the trough is associated with at least one level sensor a flowed from the lint depot through the filter into the tub aqueous liquid is detectable, and a method for operating this dryer.

Such a dryer and a method of its operation will be apparent from the publication WO 2012/022803 A1 ,

The term "dryer" used herein is not only used for laundry dryers in the true sense, but also for washer-dryer, so for combination devices, with which a washing of laundry items can be performed.

The term "fluff" as used herein means any impurities which may pass from the drying chamber into the process air channel during the course of a wet laundry drying process by means of the moist, warm process air and may be deposited in the process air channel or in heat exchangers and the like. In addition to fluff in the actual sense, this includes other foreign particles such as e.g. Hair, lime and detergent residues and dust.

The term "liquid sensor" as used herein means a sensor that can detect the presence of, in particular, an aqueous liquid. The liquid sensor is generally a level sensor.

In a dryer, in particular in a condensation dryer, air (so-called process air) through a fan via a heater in a wet laundry containing drying chamber, usually a drum, passed. The hot air absorbs moisture from the laundry to be dried. After passing through the drying chamber, the then moist, warm process air is led into a heat exchanger as a heat sink, where the moist, warm process air condenses out of the water is cooled. The lint filter is generally preceded by a lint filter for filtering lint from the moist, warm process air stream that originates from the laundry items. In addition, due to the humid atmosphere prevailing therein, fluff can also be separated from the laundry items in the heat exchanger, in particular finely divided lint, if a lint filter is present which already catches the larger lint. Such deposits in the heat exchanger can lead to a reduction in the efficiency of the heat exchanger. Moreover, when using a lint filter between the drum and the heat exchanger, it is possible for the lint filter to become clogged and thus present a considerable flow resistance. In addition, it can lead to overheating of the system and thus to a fire hazard. Also, an internal cleaning of the lint filter of adhering lint is therefore desirable.

Therefore, dryers with an internal cleaning device, in particular also those with a flushing device, have been developed. In tumble dryers equipped with an internal cleaning, impurities, especially lint, are often collected in a cassette. As a result, the cassette (herein also referred to as "fluff depot") fills with lint over time. If this cassette is filled with lint, it must generally be emptied.

From the publications EP 1 788 140 A1 and EP 1 788 141 A2 In each case a dryer for drying laundry by means of an air flow is known. In the dryer, a sieve for filtering lint from the process air stream is arranged in the area of a bearing plate. By means of a doctor blade, the lint collected on the sieve is stripped off the sieve fabric of the lint filter and stored in a container arranged adjacent to the doctor blade and to the sieve. Since the lint is stored in the dried state, they occupy a relatively large volume.

The publication DE 10 2010 039 603 A1 describes a laundry treatment appliance, comprising at least one lint filter, wherein at least one lint filter is a life lint depot. This is intended as a costly called automatic detection of the filling of a filter chamber, ie a lint, can be avoided.

However, such a laundry treating appliance is limited in view of the number of practicable drying processes. The recognition of a degree of filling of the lint, in particular a full lint, is therefore generally important.

The publication WO 2010/028992 A2 describes a dryer comprising a drying chamber for receiving a moist material and a process air guide for supplying process air into the drying chamber and for discharging process air from the drying chamber, which process air guide a heat source for heating the process air before entering the drying chamber and a heat sink for cooling the process air after its exit from the drying chamber, and arranged between the drying chamber and the heat sink first lint filter for collecting lint from the process air. The first lint filter is associated with a first cleaning device, which comprises a collector for a liquid, a first flushing line connected to the collector, a first control element located in this first flushing line and a first distributor connected to the first flushing line for distributing liquid conveyed through the first flushing line to the first lint filter and to receive trapped lint from the first lint filter and a first drain for discharging the liquid with the collected lint from the first lint filter to the collector.

The publication WO 2012/022803 A1 describes a laundry treatment appliance, in particular a tumble dryer, which has a sieve receptacle for receiving a sieve, wherein the sieve receiving at least one level measuring device for measuring at least one water level is assigned to the Siebaufnahme and wherein the Siebaufnahme is connected to a flood chamber according to the principle of communicating vessels and the at least one level measuring device is arranged and arranged for measuring at least one water level of the flood chamber. In this case, the fluidic connection can be realized by a arranged in the vicinity of a bottom of the flood chamber lower passage opening. In a preferred embodiment, a plurality of moisture sensors are at least partially disposed in the flood chamber, which respond to different levels of a liquid in the flood chamber. At the in Fig. 2 In the embodiment shown, a lint filter is located in a cup-shaped sieve receiver, wherein condensate purified in a bottom-side outlet by means of the lint filter flows into a collecting tray.

To detect the level in a creek depot, it is thus from the publication WO 2012/022803 A1 It is known to use a sensor arranged in the creek depot (also referred to herein as a "trap sensor") with which a backflow of aqueous liquid is detected in the creek depot. Thus, the level determination in the river depot is used as a measure of the degree of filling of the river deposit. The trap sensor is generally located within the more or less lint-contaminated liquid or wet lint mass. Although it is also possible to arrange liquid sensors in a flood chamber filled with relatively clean aqueous liquid. However, this structure is complex.

The publication DE 10 2009 047 155 A1 describes a condensate collection container for a laundry dryer, comprising a condensate inlet, wherein the condensate container comprises a condensate filter with at least one sieve, which is arranged fluidically between the condensate inlet and the condensate drain, and a laundry drying apparatus with such a condensate collection container. The condensate introduced into the condensate inlet flows essentially completely through the condensate filter before it can be discharged as filtered condensate through the condensate drain.

The publication DE 100 02 743 A1 describes a heat pump tumble dryer with a arranged in the process air circulation heat exchanger (evaporator), a condensate trap below the heat exchanger and a cleaning device for removing the adhering to the surface of the heat exchanger lint, wherein the dripping from the heat exchanger condensate and the lint removed from a removable Receiving plate of the condensate collecting device are added. The cleaning device is designed as a spraying device. At the in Fig. 3 shown section of a dryer is a schematic partial view of the Heat exchanger with spray water distribution device and condensate and spray water collecting device shown, the level of the collecting container can be monitored and at a predetermined level, a display device emits a signal indicative of the state and the user to empty the collection container.

The publication DE 10 2008 054 832 A1 describes a device for cleaning a arranged in a process air cycle of a washer or dryer component, wherein separated from the process air condensate enters a condensate tank, from which it flows during a cleaning process as a cleaning condensate to the component, the condensate on its way to Condensate tank flows through at least one lint filter, which is arranged separately from the condensate tank and removable. In embodiments, the lint filter has a fill level indicator and a trough conveys cleaning condensate from the component into the lint filter.

The publication DE 43 00 694 C2 describes a clothes dryer with a condenser and a condensate collecting tank, from which the condensate is supplied by means of a pump via a line to a removable receptacle or a surrounding tub, wherein the collecting vessel or the tub via a drain line to the condensate collecting tank is connected and provided in the drain line a discharge delay device. This should allow a user to recognize what kind of an existing disorder. In the description of Fig. 1 With regard to the condensate collection container, the use of a level controller for the prevention of condensate congestion is disclosed.

Against this background, it was an object of the present invention to provide a dryer with a flushing device and a Flusendepot, in which it can be reliably and easily determined when the creek depot is filled, so that an emptying or cleaning of the lint can is indicated. Also to be provided is a method of operating this dryer.

The solution of this object is achieved according to this invention by a dryer and a method for operating a dryer with the features of the respective independent claim. Preferred embodiments of the invention The method and the dryer according to the invention are listed in respective dependent claims, wherein preferred embodiments of the dryer according to the invention correspond to preferred embodiments of the method according to the invention and vice versa, even if this is not explicitly stated herein.

The invention thus relates to a dryer with a drying chamber for items to be dried, a process air duct in which a blower for the transport of process air, a heat sink, a heat source and a lint filter, a control unit, a liquid sensor, a flushing device and a collecting device for condensate and / or lint, the collecting device being designed as a lint depot with a filter which is permeable to an aqueous liquid but retaining lint and a trough for receiving the liquid passed through the filter and the trough being associated with at least one level sensor, with which an aqueous liquid which has flowed from the lint depot through the filter into the trough can be detected; Furthermore, a timing device is provided, which makes it possible to measure a time interval between a purging of a dryer component, a sensor signal of the at least one level sensor and / or a sensor signal of a Flusendepotsensors for the determination of the presence of an aqueous liquid in the river depot, and is the control unit designed to measure the time interval measured by the time measuring device as a measure of the degree of filling of the lint depot.

The heat source for heating the process air before it enters the drying chamber and the heat sink for cooling the process air after it exits the drying chamber.

The process air duct can be open or closed, so that the dryer according to the invention can be an exhaust air dryer or a circulating air dryer. According to the invention, the dryer is preferably a circulating air dryer.

According to the invention, a time measuring device is provided in the dryer which makes it possible to measure a time interval between a rinsing of a dryer component to be cleaned, a sensor signal of the at least one fill level sensor and / or a sensor signal of the flow depot sensor.

According to the invention, the control device is designed to measure the time interval measured by a time measuring device between a flushing of a dryer component, a sensor signal of the at least one fill level sensor and / or a sensor signal of the flow depot sensor as a measure of the degree of filling of the flood depot with lint.

For example, the time interval Δt _SFS1 between the triggering of a rinsing step with rinsing liquid and the response of the first level sensor in the trough can be used as a measure of the filling level F of the lint. Similarly, the time interval .DELTA.t _SF1SF2 between the response of the first level sensor and the response of the second level sensor can be used as a measure of the degree of filling F of the lint store. If a flow depot sensor is present, the time interval Δt _FDSFS1 between the response of the flow depot sensor and the response of the first fill level sensor in the trough can also be used as a measure of the degree of filling F of the lint depot. In general, Δt _SFS1 , Δt _SF1SF2 and Δt _FDSFS1 increase as the fill level of the lime dump increases.

In the control _device , a relationship is generally stored for this determination between .DELTA.t _SFS1 , At _SF1SF2 and / or .DELTA.t _FDSFS1 and the _{degree of} filling F. This relationship can also be deposited for different amounts of flushing liquid. In accordance with the invention, the determination of the degree of filling can be carried out in the context of a rinsing step in which comparatively much aqueous liquid is used, or else in a separate measuring step for determining the degree of filling in which, if appropriate, little aqueous liquid can be used. Thus, in the dryer may be a counter that counts the performed drying processes, for example the drying processes carried out after a final emptying of the river deposit. As long as the number of drying processes carried out is low, should be sufficient for the separate measuring step, but also for the rinsing step, a comparatively small amount of rinsing liquid.

The dryer according to the invention also makes it possible in particular to determine the absence of a lint filter and a collecting device in a dryer. In a preferred embodiment of the dryer, therefore, the control device is designed so that when measuring a time interval .DELTA.t <.DELTA.t _{min is closed} on the absence of the lint filter. In this case .DELTA.t _{min is} the period of time that requires a liquid used for cleaning ("rinsing liquid") from the rinsing device from the initiation of a rinsing step at least to reach after passing through an empty lint and possibly a clean lint filter a first level sensor. Δt and Δt _min may vary depending on the liquid sensors used for the determination.

According to the invention, the collecting device for condensate and / or lint is designed as a lint depot with a filter which is permeable to an aqueous liquid but can retain lint. The term "Flusendepot with a filter" is hereby interpreted broadly. For example, the lint can be designed as a rigid chamber whose bottom is perforated for the passage of an aqueous liquid. In such a rigid chamber can be arranged as a filter, a rigid filter material, for example in the form of a perforated sheet metal part or a perforated plastic part. In another embodiment, the filter is configured as a sieve or a filter bag, wherein in particular a filled with fluff filter bag for disposal from the dryer or the rigid chamber can be removed. In this case, the filter may comprise a fabric, for example a fleece. Finally, in another embodiment, the lint can be releasably or permanently connected to the filter. In both embodiments, the lint depot is generally removable from the dryer. In this way, either the river depot can be emptied as such or a filter bag contained in this can be replaced. The filter is also preferably a rigid filter or screen in the last embodiment. The filter may also include a filter cloth held by a rigid support.

In one embodiment of the dryer according to the invention, the fill level sensor is arranged in the trough.

In one embodiment, the collecting device has a rigid, open-topped container as a flute depot, in the bottom of which and possibly in its side walls a plurality of holes are arranged, through which an aqueous liquid can flow. This container may be lined on its inside with a filter fabric. The holes then serve not to retain lint, but in particular a good passage for a purified rinsing liquid, e.g. purified condensate. Such a solution enables a stable support for the filter fabric. Alternatively, the holes may be sized so that the container as such exhibits the desired filtering action.

The lint depot and in particular the filter are preferably at least partially antimicrobial designed to suppress the formation of microorganisms (bacteria, fungi) in the deposited lint. As a result, a possible decomposition of the lint and an associated odor development can be avoided. For this purpose, the lint depot and filter may at least partially have a superficial coating which contains, for example, copper or silver or consists of this. Such a coating is particularly durable and antimicrobial effective.

In one embodiment of the dryer according to the invention, the trough is arranged in the dryer below the lint. The tub can be arranged for example in the bottom group of the dryer or form the bottom group. This arrangement of the tub below the lint can generally makes it possible for an aqueous Liquid in the river depot can flow through the filter into the trough solely due to the gravitational force. The type and shape of the tub are not limited, as long as an aqueous liquid can be collected and then suitably removed from the tub.

For example, the tub may be designed as a pure receptacle, which can be emptied at a given time, for example, by removing the tub from the dryer. Since the aqueous liquid in the trough is a filtered, relatively clean aqueous liquid, it can be used in many different ways.

In a preferred embodiment of the dryer according to the invention, however, the filtered through the filter aqueous liquid from the tub is passed into a reservoir, which is also referred to herein as a "condensate tank". For this purpose, the tub is preferably connected via a pipe or hose line, which is also referred to herein as "condensate line", and generally a pump, which is referred to herein as a "condensate pump" connected to the condensate tank. The condensate container in particular allows a longer storage of the filtered aqueous liquid, for example, for further use in the dryer. If present, the condensate container in the dryer according to the invention serves in particular as a reservoir for an aqueous rinsing liquid as a component of a rinsing device.

According to the invention, the trough is assigned at least one fill level sensor. The level sensor is not limited according to the invention, as long as it is possible with him to determine the level of an aqueous liquid. For example, the level sensor can be a conductivity sensor or an optical sensor, or have a float arranged in the tub, which is coupled to or has a reed sensor or reed switch. In addition, the level sensor may be a system of several of these sensors. Preferably, the at least one level sensor is a conductivity sensor and / or an optical sensor. A conductivity sensor generally consists of a pair of electrodes, between which an electric field is applied, so that the conductivity of a medium present between the electrodes, for example water, can be measured. Since the conductivity of water is significantly greater than that of air, the presence of water can be determined by measuring the conductivity.

According to the invention, it is preferable for a first fill level sensor, which responds upon reaching a first fill level H ₁ , and a second fill level sensor, which responds upon reaching a second fill level H ₂ , to be present, wherein H ₁ <H ₂ . Herein, "sensor response" means that a sensor signal measured by the sensor indicates the presence of an aqueous fluid. The at least one fill level sensor makes it possible for the time span required by a flushing liquid from the flushing device to reach the at least one fill level sensor to be evaluated with regard to a functioning separation of lint. For this purpose, in the presence of, for example, two level sensors, which respond at different levels of an aqueous liquid, the time interval between a response of the first and the second level sensor with respect to the presence of aqueous liquid are measured and evaluated with regard to the degree of filling F of the lint ,

The term "degree of filling" is to be interpreted practically. According to the invention, it should be possible, in particular, to prevent overflow of the lint depot with liquid. In addition, a rapid flow of an aqueous liquid should be possible from the Flusendepot so that, for example, a condensate pump operated properly and a condensate tank can be filled as efficiently as possible. According to the invention, it is therefore already possible to conclude a "full" flute depot and to indicate the necessity of evacuation if the flusepepot is not completely filled with lint, but opposes a high flow resistance to the aqueous liquid.

In a preferred embodiment of the invention, a flow depot sensor for determining the presence of an aqueous liquid in the flute depot is arranged in the flume depot of the dryer. Such a Flusendepotsensor (also referred to as "case sensor") is as discussed above, for example in the WO 2012/022803 A1 rubbed closer.

Usually, the rinsing of a dryer component to be cleaned takes place in a surge-like manner by contacting an aqueous liquid as the rinsing liquid with the dryer component to be cleaned in a relatively short period of time. As a reference point for the determination of the time interval, therefore, the triggering of a rinsing step is preferably assumed.

Preferably, the control device is designed so that upon detection of reaching a predetermined maximum degree of filling F _{max of} the lint, or in the case of a missing lint or filter, a drying process can no longer be performed and / or a start of a new drying process is suppressed until the lagoons emptied has been.

The dryer component to be cleaned according to the invention is not limited. However, in particular, the heat sink and a lint filter tend to deposit lint. It is therefore preferred according to the invention for the dryer component to be cleaned to be the heat sink and / or the lint filter. In a preferred embodiment of the dryer, the lint depot is arranged below a heat sink to be cleaned (eg an air-air heat exchanger). This eliminates the need for a special channel from the heat exchanger to the lint filter. Instead, the liquid can pass directly from the heat exchanger into the lint filter.

The heat source and the heat sink are not limited according to the invention. For example, the heat source may be an electric heater, a fuel heater (gas, oil) or a condenser of a heat pump. The dryer according to the invention also has a heat sink in which the moist, warm process air is cooled to form condensate. The heat sink may be, for example, an air-to-air heat exchanger or a heat sink of a heat pump, for example an evaporator. If the heat source is an electric heater or a gas or oil heater, the heat sink is generally an air-to-air heat exchanger. If, on the other hand, a condenser of a heat pump is present as the heat source, the evaporator of the heat pump is used as the heat sink, above all.

In a preferred embodiment, the dryer has a heat pump. In particular, in a dryer equipped with a heat pump, an internal cleaning of the heat exchanger, in particular the heat sink (evaporator), makes sense, since the components of a heat pump are generally firmly connected to each other, so that the heat exchanger can not be removed for cleaning. For this case, it is particularly advantageous to clean the heat sink with a flushing device present in the dryer of fluff that could not be caught by the lint filter and have deposited on the evaporator.

The heat pump may be a thermoelectric heat pump or, preferably, a compressor-type heat pump. The heat sink is therefore preferably the evaporator of a heat pump of the compressor type.

A heat pump clothes dryer generally has a closed process air cycle and a heat pump cycle (also referred to herein as "refrigerant cycle"). In a dryer equipped with a compressor-type heat pump, the cooling of the warm, moisture-laden process air substantially takes place in the heat sink evaporator of the heat pump, where the heat transferred is used to evaporate a refrigerant circulating in the heat pump. The vaporized refrigerant reaches the Compressor and from the compressor to the condenser, where it is liquefied with the release of heat. The heat released heats the process air. The liquefied refrigerant flows through a throttle, where its internal pressure is reduced, back to the evaporator, which closes the circuit.

In a particularly preferred embodiment, the dryer has a display device which can display a user information about the filling of the river storage. The display device may in particular be an optical and / or acoustic display device. For example, the display device may be configured to indicate to a user the actual degree of filling of the lint store with lint or to indicate to a user that the lint is to be emptied only upon detection of reaching a predetermined degree of filling F _{1 of} the lint. In addition, the visual and / or acoustic display device can enable the user of the dryer to display eg operating parameters and / or an expected duration of the drying process.

The case that a determination of reaching a predetermined maximum degree of filling F _{max of} the flow depot aborted a drying process and / or a start of a new drying process is prevented, can also be displayed on a display device.

The dryer according to the invention has a flushing device. The rinsing device is generally designed to provide an aqueous liquid for cleaning dryer components to be cleaned. In this case, this aqueous liquid (also referred to herein as "rinsing liquid") in the dryer accumulating condensate, which should be as clean as possible, and / or tap water of an optionally connected external water supply.

According to the invention, a dryer is preferred in which the flushing device comprises a condensate tank which is connected to the tank via a condensate line and a condensate pump. This allows the provision of filtered condensate as a rinsing liquid.

The lint filter absorbs most of the lint that results from a drying process in the dryer. These fluff as well as the lint from a heat sink go into the rinsing liquid. The river depot can catch these lint. The rinsed fluff forms a relatively compact wet lump, which can generally be disposed of easily and without dust formation.

The flushing device allows several dryer components to be flushed with the flushing liquid at the same time or at different times. For this purpose, the flushing device generally has different flushing lines, which can be opened and closed with controllable closure devices, generally valves. In addition, there are generally suitable rinse liquid dispensers on the dryer components.

The invention also relates to a method of operating a dryer having a drying chamber for laundry items to be dried, a process air duct containing a blower for conveying process air, a heat sink, a heat source and a lint filter, a control unit, a liquid sensor, a flushing device and a trap for condensate and / or lint, wherein the catcher is configured as a flute depot having a filter that is permeable to an aqueous liquid but retains lint and a sump for holding the liquid left by the filter, and the sump is at least one level sensor is assigned, with which a flowed from the lint depot through the filter into the tub aqueous liquid is detectable; Furthermore, a timing device is provided, which allows a time interval between a purging of a dryer component, a sensor signal of the at least one level sensor and / or a sensor signal of a Flusendepotsensors for the determination of the presence of an aqueous liquid in the Flusendepot as a measure of the degree of F of Flusendepots to be measured, wherein a time required by a rinsing liquid from the rinsing device to reach the at least one level sensor time with regard to a functioning separation of lint is evaluated.

In a preferred embodiment of the method, the time required by a rinsing liquid from the rinsing device until the at least one level sensor is reached is evaluated with regard to a functioning separation of lint, using a time-measuring device provided in the drier which allows measure a time interval between a purging of a dryer component, a sensor signal of the at least one level sensor and / or a sensor signal of a flow depot sensor arranged in the lint depot, and a control device that is designed to measure the time interval between the purging of a dryer component measured by the time-measuring device to evaluate the sensor signal of the at least one fill level sensor and / or the sensor signal of the Flusendepotsensors with regard to a functioning separation of lint.

A further preferred embodiment of the method makes it possible to determine the absence of the lint filter by concluding the absence of the lint filter when measuring a time interval Δt <Δt _min . The dryer according to the invention also makes it possible in particular to determine the absence of a collecting device in a dryer. In a further preferred embodiment of the method according to the invention, therefore, the control device is designed so that when measuring a time interval Δt <Δt _min can be concluded not only on the absence of a lint filter, but also on the absence of a collecting device for condensate and / or lint. In this case .DELTA.t _{min is} the period of time that requires a liquid used for cleaning ("rinsing liquid") from the rinsing device from the initiation of a rinsing step at least to reach after passing through an empty lint and possibly a clean lint filter a first level sensor. Δt and Δt _min may vary depending on the liquid sensors used for the determination.

Incidentally, it can also be determined for such a determination whether there is a short-term detection of the case sensor. If this does not happen, the catcher is not present. Incidentally, a missing catching device or a missing lint screen is present if the time interval for the sensor signals between the fall sensor and the first fill level sensor or between the first fill level sensor and the second fill level sensor is too small.

In addition, a method is preferred in which with an aqueous liquid from the flushing device, which comprises a condensate tank, which is connected via a condensate line and a condensate pump with the tub, a dryer component in The process air duct is rinsed and the aqueous liquid passing through the filter into the sump is returned to the condensate tank by means of the condensate pump in the condensate line.

In a further preferred embodiment of the method according to the invention, it is taken into account which time span has elapsed since the execution of a last drying process and the measurement of the degree of filling of the river deposit in order to determine the influence of the moisture content of the lint in the river depot on the evaluation. In this case, it is advantageously possible to predefine a period Δt _{set to} be maintained at least after which a certain moisture content is present in the river depot, for example on the basis of empirical values.

The invention has numerous advantages. Thus, a dryer is provided by the invention, in which a maintenance case, in particular the need for emptying a lint, in a simple and rapid manner can be determined and displayed. In addition, it can be easily recognized whether a fluff grid is present in the process air duct. Finally, it can also be determined in the case of a removable flotation depot, if the Flusendepot ever installed. An internal cleaning of the dryer is particularly important in heat pump dryers of importance. The invention therefore makes possible in particular an improved operation of a dryer with a heat pump.

The invention makes it possible to automatically determine the point in time at which the river depot should or should be emptied, and that emptying intervals specified in a user manual need not be complied with. The invention also makes it possible in a simple manner to prevent the filter chamber or the filter bag from overflowing by notifying a user of a necessary emptying or cleaning of the fluid depot, or, if such instructions are not followed, further operation of the dryer prior to such cleaning finally is no longer possible.

Further details of the invention will become apparent from the following description of an embodiment of a dryer and a method for operating this dryer. Reference is made to the FIGS. 1 to 3.g , Figure 1 shows a vertical section through a dryer, which according to a preferred embodiment is a heat pump dryer.

Fig. 2 schematically shows the essential parts of the dryer of the present invention of Fig. 1 ,

Fig. 3 shows in the case that a case sensor is present in the dryer, the relationship between the time interval of sensor signals at the case sensor and the first level sensor and the filling of the collecting device for condensate and / or lint.

The Fig. 1 shows a vertical section through a dryer, which is a heat pump dryer according to a first embodiment of the invention, in which the heat source, the condenser 23 and the heat sink, the evaporator 21 of a heat pump 21,22,23,24 compressor type. The vaporized in the evaporator 21 refrigerant of the heat pump 21,22,23,24 is passed through the compressor 24 to the condenser 23. In the condenser 23, the refrigerant liquefies under heat to the process air flowing in the process air duct 4 process air. The now present in liquid refrigerant is passed through the throttle 22 in turn to the evaporator 21, whereby the refrigerant circuit 20 is closed.

The drier 1 comprises a drying chamber 2 (washing drum 2) designed as a rotatable drum, which receives moist laundry items 3. At the in FIG. 1 In the embodiment shown, the dryer 1 has a closed process air duct 4, in which, driven by a fan 5, a process air flow is circulated, which absorbs and removes moisture from the laundry items 3. In the condenser 23 of the heat pump as a heat source, the process air is heated before it enters the drying chamber 2. After the heated process air flows around the laundry items 3 and / or flows through them, it leaves the drying chamber 2 and passes over a lint filter 12 to the evaporator 21 of the heat pump as a heat sink. There it is cooled, so that the entrained moisture condenses and precipitated as condensate in liquid form on the structures of the evaporator 21 and dripped into a arranged below the evaporator 21 collecting device 6 for lint and condensate.

At the in Fig. 1 As shown in the embodiment of a dryer according to the invention, the lint filter 12 is cleaned by means of an aqueous liquid (also referred to herein as "rinsing liquid") from a rinsing device 11, 15, which here comprises a condensate container 11 and a lint filter cleaning device 15. The flushing device thus comprises a condensate tank 11, which is connected via a condensate line 13 and a condensate pump 14 to the tub 8. For rinsing, the rinsing liquid passes to the lint filter cleaning device 15, which makes the rinsing liquid suitable for rinsing on the lint filter 12. The rinsing liquid then passes together with rinsed lint via a flushing water discharge 16 also in the collecting device 6. The rinsing liquid is in this case in particular collected condensate from previous drying processes. In the case of the dryer 1 of the embodiment shown here, the condensate container 11 is additionally connected via a third controllable closure device 31 and a supply line 32 to an external water supply. This allows the additional or alternative use of tap water as rinse water.

The control of dryer 1 via a control unit 18, which can be controlled by the user via a control unit, not shown here, which allows the user of the dryer 1 to select from a variety of programs offered a desired for the drying process to be carried out drying program. Moreover, the control unit 18 can control the implementation of the method according to the invention.

The lint filter 12 generally can not completely absorb the fluff entrained by the process air. A finely divided proportion of lint will pass through the lint filter 12. These finely divided fluff then settle more or less completely in the evaporator 21, wherein the condensate occurring there promotes adhesion to the inner surface of the evaporator 21. These fluff can significantly affect the function of the evaporator 21, so that in particular its efficiency decreases. In addition, it should be noted that because of the required complete sealing of the refrigerant circuit 20, a removal of the evaporator 21 from the dryer 1 for the purpose of cleaning is not possible. Therefore, the evaporator 21 is associated with a Wärmesenkenspülvorrichtung 25, which also uses the present in the condensate tank 11 aqueous liquid as a rinsing liquid to rinse the process air exposed surfaces of the evaporator 21 and remove the resulting lint. For this purpose, a heat sink flushing line 29 with a valve 28 arranged therein is connected to the condensate tank 11 as a second controllable closure device which connects the condensate tank 11 with the heat sink flushing device 25 designed as a distributor. The rinsing liquid loaded with lint flows into the lint depot 6. In the event that a relatively strong flow of the rinsing liquid is desired for the corresponding cleaning purpose, a pump may be provided in addition to each valve 27 or 28. Optionally, a single pump could be associated with both valves 27 and 28.

From the collecting device 6, which is configured here as a lint depot with a filter 7, which is permeable to an aqueous liquid, but holds back lint, the aqueous liquid or rinsing liquid can flow through the filter 7 and into a arranged below the lint 6 bucket. 8 reach. The tub 8 is here a bottom tray of the dryer.

In the trough 8, in the embodiment shown here, a first fill level sensor 9, which responds when a first fill level H _{1 is reached} , and a second fill level sensor 10, which responds upon reaching a second fill level H ₂ , where H ₁ <H ₂ , are present , In addition, in this embodiment, in the river depot 6, a pile depot sensor 30 for determining the presence of an aqueous liquid is disposed in the river deposit 6. The two level sensors 9 and 10 as well as the Flusendepotsensor 30 are configured in the embodiment shown here as conductivity sensors.

Moreover, the dryer 1 has a time measuring device 19, which makes it possible to measure a time interval, ie a period of time, between rinsing a dryer component 12, 21 with a rinsing liquid, sensor signals of the two fill level sensors 9 and 10 and the flow deposit sensor 30.

Moreover, the control unit 18 is configured such that the time interval measured by the time measuring device 19 between the purging of the dryer components, here the lint filter 12 and the evaporator 21, and sensor signals of the two level sensors 9, 10 and / or a sensor signal of the flow depot sensor 30 as a measure can be used for the degree of filling F of the lint 6.

In principle, the measurement of a single time interval between two of these sensors is sufficient for the measurement of the degree of filling F of the fluid depot 6. However, increased measurement accuracy is obtained when multiple time intervals, i. the time intervals between different sensor pairs are measured.

In the case of the dryer 1, the control unit 18 is configured such that, when a predetermined maximum filling F _max of the cascade depot 6 has been reached, a drying process can no longer be carried out until the cascade depot 6 has been emptied.

Incidentally, in the case of the dryer 1 shown here, the control unit 18 is designed such that, when a time interval Δt <Δt _{min is} measured, it is possible to conclude the absence of the lint filter 12 and / or the lint depot 6 with the filter 7.

The condensate tank 11 is in the embodiment shown here otherwise designed so that it can be taken out of the dryer 1, in particular after completion of a drying process to pour the liquid out of him and supply it to a suitable disposal or possibly clean it, as a gradual accumulation of extremely finely divided lint or dust in the condensate tank 11 can not be excluded. However, in the embodiment shown here, after filtration through the filter 7, a relatively clean aqueous liquid is produced, which is used to clean dryer components in the process air duct 4 or for other purposes, e.g. for ironing, can be used.

The dried process air in the evaporator 21 is further led to a condenser 23 of the heat pump as a heater and passed from there back into the laundry drum 2. An optical / acoustic display device 17 allows the user of the dryer 1 to display eg operating parameters and / or an expected duration of the drying process. The display device 17 also indicates upon detection of reaching a predetermined degree of filling F _{1 of} the lint 6, that the lint 6 should be emptied. If a predetermined maximum degree of filling F _{max is} reached, this state is also displayed.

According to the invention, both the lint filter 12 and the evaporator 21 can be cleaned of lint by being flushed with flushing liquid from the condensate container 11 at the same time or individually. The rinsing liquid can be, for example, fresh water from a water supply of the drier 1 and / or condensate, which is preferably stored in a condensate tank 11 for this purpose. The rinsing can be done for example by a rapid emptying when the condensate tank 11 in the dryer 1 is relatively high. The condensate, etc., thus splashes on the lint filter 12 and / or the evaporator 21 and tears the lint present there, etc. with. The then lint-laden condensate enters the lint 6 and is separated by the filter 7 of lint. The existing in the Flusendepot 6 condensate thus passes through the filter 7 leaving the lint, etc. and can continue to flow to the condensate pump 14, which can pump the largely lint-free condensate to a drain, not shown here or back into the condensate tank 11.

In the dryer 1, a method according to the invention can be carried out in which the time required by a rinsing liquid from the rinsing device 11, 15 to reach the at least one level sensor 9, 10 is evaluated with regard to a functioning separation of lint. In this case, by means of the time measuring device 19, a time interval between a flushing of a dryer component 12,21, a sensor signal of the two level sensors 9,10 and / or a sensor signal of the Flusendepotsensors 30 are measured and then by means of the control unit 18 of the time measuring device 19 measured time interval between the flushing of a dryer component 12, 21, the sensor signal of the at least one fill level sensor 9, 10, and / or the sensor signal of the flood depot sensor 30 are evaluated with regard to the degree of filling of the flood depot 6. Finally, when measuring a time interval .DELTA.t <.DELTA.t _min, for example, the absence of the lint filter 12 can be concluded.

Finally, the dryer 1 described here enables a method for its operation, in which with an aqueous liquid from the flushing device 11,15, which comprises a condensate tank 11 which is connected via a condensate line 13 and a condensate pump 14 with the trough 8, a dryer component 12,21 is rinsed in the process air duct 4 and the passing through the filter 7 in the tub 8 aqueous liquid is conveyed by means of the condensate pump 14 in the condensate line 13 back into the condensate tank 11.

In a drying process, process air is generally circulated repeatedly through the process air duct 4 until preferably a desired degree of drying of the laundry items 3 is achieved.

Fig. 2 schematically shows the essential parts of the dryer of the present invention of Fig. 1 ,

Shown here is part of a flushing device, a condensate tank 11, which is connected via a condensate line 13 with a trough 8, so that an entering into the tub 8 aqueous liquid can be conveyed into the condensate tank 11. The condensate tank 11 is also connected via a Flusensiebspülleitung 26 with a lint filter 12 and a Wärmesenkenspülleitung 29 with the evaporator 21 of a heat pump not shown here. The lint filter 12 and the evaporator 21 are thus here to be cleaned dryer components. The rinsing liquid used for cleaning from the condensate tank 11 finally arrives after a cleaning of one or both dryer components directly or via a rinsing water discharge 16 into the collecting device 6, which is separated from the trough 8 by a filter 7. The filter 7 retains lint, but leaves the purified rinsing liquid through, which can therefore reach the condensate tank 11 via the condensate line 13.

Fig. 3 shows in the case that a case sensor is present in the dryer, the relationship between the time interval of sensor signals at the case sensor and the first level sensor (At _FDSFS1 ) and the _{degree of} filling of the collecting device for condensate and / or lint. As a measure of the degree of filling here is the number of carried out after emptying the lint drainage drying processes. With increasing number of drying processes increases the filling of the catcher with lint. The fluff are arranged on the filter, which separates the collecting device from an underlying trough, in which the first level sensor is arranged. Since the lint is a flow resistance for the aqueous liquid flowing out of the collecting device into the trough, the time interval .DELTA.t between the sensor signals of a sensor pair increases with increasing degree of filling of the lint catcher. In particular, the time interval Δt _FDSFS1 between the response of the flow depot sensor and the response of the first fill level sensor in the trough will also increase as a measure of the fill level F of the lint store.

reference numeral

1

dryer

2

Drying chamber, (laundry) drum

3

laundry

4

Process air duct

5

fan

6

Collecting device for lint and / or condensate; Flusendepot

7

Filter, Flusendepotfilter

8th

Tub (below the creek deposit); floor pan

9

First level sensor; liquid sensor

10

Second level sensor; liquid sensor

11

condensate tank

12

lint

13

condensate line

14

condensate pump

15

Flusenfilterreinigungsvorrichtung

16

Spülwasserableitung

17

optical / acoustic display device

18

control unit

19

Timing device

20

Refrigerant circulation

21

Heat sink, e.g. Evaporator of a heat pump

22

throttle

23

Heat source, e.g. Condenser of a heat pump

24

compressor

25

Wärmesenkenspülvorrichtung

26

Flusensiebspülleitung

27

First adjustable closure device; Valve

28

Second adjustable closure device; Valve

29

Wärmesenkenspülleitung

30

Flusendepotsensor

31

Third adjustable closure device; Valve (for external water supply)

32

Supply line for external water supply

Claims (15)

1. Dryer (1) having a drying chamber (2) for laundry items (3) to be dried, a process air duct (4), in which are disposed a fan (5) for conveying process air, a heat sink (21), a heat source (23) and a lint filter (12), having a control unit (18), a liquid sensor (9, 10, 30), a flushing device (11, 15) and a collection device (6) for condensation and/or lint, wherein the collection device (6) is embodied as a lint receptacle with a filter (7), which is permeable to aqueous liquid, but retains lint, and with a trough (8) for receiving the liquid allowed through the filter (7), and the trough (8) is assigned at least one fill level sensor (9, 10), with which an aqueous liquid that has flowed out of the lint receptacle (6) through the filter (7) into the trough (8) can be detected, characterised in that a time measuring device (19) is provided which allows the measurement of a time lag between a flushing of a dryer component (12, 21), a sensor signal of the at least one fill level sensor (9, 10) and/or a sensor signal of a lint receptacle sensor (30) for determining the presence of an aqueous liquid in the lint receptacle (6), and the control unit (18) is designed to measure the time lag measured by the time measuring device (19) as a measure of the fill level F of the lint receptacle (6).
2. Dryer (1) according to claim 1, characterised in that the fill level sensor (9, 10) is arranged in the trough (8).
3. Dryer (1) according to claim 2, characterised in that the trough (8) is arranged below the lint receptacle (6).
4. Dryer (1) according to one of the preceding claims, characterised in that the at least one fill level sensor (9, 10) is a conductivity sensor and/or an optical sensor.
5. Dryer (1) according to one of the preceding claims, characterised in that a first fill level sensor (9), which responds when a first fill level H ₁ is reached, and a second fill level sensor (10), which responds when a second fill level H₂ is reached, are provided, wherein H₁< H ₂.
6. Dryer (1) according to one of the preceding claims, characterised in that arranged in the lint receptacle (6) is a lint receptacle sensor (30) for determining the presence of an aqueous liquid in the lint receptacle (6).
7. Dryer (1) according to one of claims 1 to 6, characterised in that the dryer components (12, 21) are the heat sink (21) and/or the lint filter (12).
8. Dryer (1) according to one of claims 6 to 7, characterised in that the control unit (18) is designed such that the absence of the lint filter (12) is indicated if a time lag Δt<Δt_min is measured.
9. Dryer (1) according to one of the preceding claims, characterised in that the dryer (1) has an optical and/or acoustic display device (17), which, upon establishing that a predetermined fill level F ₁ of the lint receptacle (6) has been reached, indicates that the lint receptacle (6) is to be emptied.
10. Dryer (1) according to one of the preceding claims, characterised in that the control unit (18) is embodied such that a drying process can no longer be performed upon establishing that a predetermined maximum fill level F_max of the lint receptacle (6) has been reached, and/or a start of a new drying process is prevented until the lint receptacle (6) has been emptied.
11. Dryer (1) according to one of the preceding claims, characterised in that the flushing device (11, 15) comprises a condensation container (11), which is connected via a condensation line (13) and a condensation pump (14) with the trough (8).
12. Method for operating a dryer (1) having a drying chamber (2) for laundry items (3) to be dried, a process air duct (4), in which are disposed a fan (5) for conveying process air, a heat sink (21), a heat source (23) and a lint filter (12), having a control unit (18), a liquid sensor (9, 10, 30), a flushing device (11, 15) and a collection device (6) for condensation and/or lint, wherein the collection device (6) is embodied as a lint receptacle with a filter (7), which is permeable to aqueous liquid, but retains lint, and with a trough (8) for receiving the liquid allowed through the filter (7), and the trough (8) is assigned at least one fill level sensor (9, 10), with which an aqueous liquid that has flowed out of the lint receptacle (6) through the filter (7) into the trough (8) can be detected, characterised in that a time measuring device (19) is provided which allows the measurement of a time lag between a flushing of a dryer component (12, 21), a sensor signal of the at least one fill level sensor (9, 10) and/or a sensor signal of a lint receptacle sensor (30) for determining the presence of an aqueous liquid in the lint receptacle (6) as a measure of the fill level F of the lint receptacle (6), wherein a period of time required by a flushing liquid from the flushing device (11, 14) until the at least one fill level sensor (9, 10) is reached is evaluated in respect of a functioning separation of lint.
13. Method according to claim 12, characterised in that the period of time required by the flushing liquid is evaluated using the time measuring device (19) and a control device (18), which is designed to evaluate the time lag measured by the time measuring device (19) in respect of a functioning separation of lint.
14. Method according to one of claims 12 and 13, characterised in that the absence of the lint filter (12) is indicated if a time lag Δt<Δt _min is measured.
15. Method according to one of claims 12 to 14, characterised in that a dryer component (12, 21) in the process air duct (4) is flushed using an aqueous liquid from the flushing device (11, 15), which comprises a condensation container (11), which is connected via a condensation line (13) and a condensation pump (14) to the trough (8) and the aqueous liquid passing through the filter (7) into the trough (8) is conveyed by means of the condensation pump (14) in a condensation line (13) back into the condensation container (11).

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