EP3090093B1

EP3090093B1 - Laundry treatment apparatus with fluff filter washing arrangement

Info

Publication number: EP3090093B1
Application number: EP13814997.6A
Authority: EP
Inventors: Alberto Bison; Nicola Reid; Giuseppe Rossi
Original assignee: Electrolux Appliances AB
Current assignee: Electrolux Appliances AB
Priority date: 2013-12-30
Filing date: 2013-12-30
Publication date: 2018-12-19
Anticipated expiration: 2033-12-30
Also published as: WO2015101387A1; EP3090093A1

Description

The invention relates to a laundry treatment apparatus, in particular dryer, condensate dryer, heat pump tumble dryer or washing machine having a dryer function, the apparatus comprising a fluff filter and a washing liquid collector arranged for collecting liquid carrying fluff washed off from the filter surface.
DE 10 2008 054 832 A1 teaches an apparatus and a method for cleaning a device arranged within a process air circuit, wherein a liquid condensed from the process air is guided to a condensate tank from where it is flowing to the device for the cleaning process. A fluff filter is arranged separately from the condensate tank and adapted for removing fluff from the condensed liquid before it reaches the condensate tank.
EP 2 072 660 A1 discloses a laundry dryer, wherein a process air fluff filter is washed with condensate conveyed to a nozzle by means of a pump. The fluff filter is arranged close to a laundry door opening. A Y-valve is provided such that the pump may convey condensate to the nozzle or discharges condensate to the outside of the dryer. After cleaning the fluff filter, contaminated washing water is conveyed to a tank where it is filtered by a filter unit. The filtered (clean) water flows through an outlet back into the base unit. The filter unit is removable for cleaning by a user
EP 0 816 549 A2 discloses a washer dryer comprising a sliding filter which is cleaned via a sprinkler nozzle with condensate collected in a condensate tank and pumped by an auxiliary pump. A washing water collection tank is directly connected to a drain/discharge pump. A flow diverter directs the flow generated by the pump to the nozzle or to the drum in case the pump is also used for recycling washing water or rinsing water. The tanks are located at a higher level than the maximum filling level of the washing tank to avoid back-ups of washing liquid.
DE 10 2009 001 548 A1 discloses a heat pump laundry dryer, wherein an process air fluff filter is cleaned with condensate which has been conveyed from a main condensate collector to a rinsing tank. A diverter directs condensate to the air fluff filter. Contaminated washing liquid flows to a fluff depot where fluff is filtered from the water and clean water flows into the main condensate collector. A user has to clean the removable fluff depot.
EP 2 196 577 A1 discloses a laundry dryer with a process air fluff filter which is washed with condensate from a container. Contaminated washing liquid flows into a collecting tank and via a conduit back into a main condensate collector in a base unit.
EP 0 356 689 A1 discloses a clothes dryer comprising a siphon that is disposed on the bottom of a cooling water-containing portion of a condensation unit to drain cooling water and condensed water.
It is an object of the invention to provide a laundry treatment apparatus comprising a fluff filter and an improved arrangement for cleaning the fluff filter.
The invention is defined in claim 1. Particular embodiments of the invention are set out in the dependent claims.
According to claim 1, a laundry treatment apparatus, in particular dryer, condensate dryer, heat pump tumble dryer, or washing machine having a dryer function, comprises a control unit, an apparatus cabinet, a laundry treatment chamber, and a fluff filter. The control unit is arranged for controlling the operation of the laundry treatment apparatus. The laundry treatment chamber is adapted for treating laundry stored therein using process air that is circulated in a process air circuit. The process air is cooled at a heat exchanger arranged in the process air circuit whereby humidity carried by the process air is condensed, and a condensate collector is assigned to the heat exchanger for collecting the condensate condensed at the heat exchanger. The fluff filter is arranged in the process air circuit upstream the heat exchanger for filtering fluff from the process air passing the fluff filter. In particular the fluff filter is arranged in the process air channel between the laundry treatment chamber and the heat exchanger. Assigned to the fluff filter, there is a washing liquid collector adapted to collect washing liquid from the fluff filter. A condensate pump is arranged in liquid connection to the condensate collector and adapted to convey the collected condensate. The condensate pumped by the condensate pump is received by a condensate directing means adapted to selectively direct the condensate flow under the control of the control unit either to a condensate sink or to the fluff filter for washing at least a portion of the filter surface by removing fluff. Preferably the collected condensate is provided from an outlet or nozzle such that the entire or essentially the entire filter surface filtering fluff is washed. The fluff filter and the washing liquid collector are arranged such that the washing liquid is flowing along at least a portion of the surface of the fluff filter and is carrying fluff washed off from the surface into the washing liquid collector which is adapted to collect the contaminated washing liquid.
Here and in the following, condensate that is supplied to the fluff filter for filter washing is denoted "washing liquid". Herein 'contaminated' means that the liquid comprises fluff or other contaminants or particles collected at the fluff filter during a drying process. The 'washing liquid' is not contaminated as it is formed by the condensate which is not or only extremely minimally contaminated by fluff that unintentionally passed the fluff filter towards the heat exchanger.
The condensate collector is dedicated exclusively to the heat exchanger, i.e. it exclusively collects condensate from the heat exchanger and receives no or substantially no liquid from other sources, namely no or essentially no washing liquid from filter washing. Washing liquid from filter washing is received by a washing liquid collector that is separate from the condensate collector.
The fluff filter is positioned in a bottom region within the apparatus cabinet and/or the basement of the apparatus. (Here and in the following the basement of the apparatus will also be denoted "base unit" of the apparatus.)
In an embodiment, the fluff filter is designed such that the washing liquid is flowing along the surface of the filter from where the washing liquid is applied and such that no or substantially no washing liquid is passing through the fluff filter. In addition or alternatively, at least one washing liquid outlet and/or nozzle for applying the washing liquid to the fluff filter is arranged relative to the fluff filter such that the washing liquid is applied at that side of the fluff filter which is exposed to the fluff transported in the process air from the laundry treatment chamber.
In an embodiment, the laundry treatment apparatus further comprises a drain pump in liquid connection to the washing liquid collector to convey the contaminated washing liquid to a drain outlet for draining the contaminated washing liquid to a contaminated washing liquid sink.
In an embodiment, the drain pump is arranged within the apparatus cabinet either between a process air fan or a cooling air fan and a front wall of the apparatus cabinet or between a heat pump refrigerant compressor and a front wall of the apparatus cabinet.
According to an embodiment, the outlet of the condensate directing means which directs the condensate flow towards the condensate sink is connected to an inlet of a conduit, wherein the conduit has an outlet and wherein a siphon is arranged in the conduit between the inlet and outlet such as to prevent compensation of pressure differences by an airflow between the both ends of the conduit when the condensate pump is stopped and liquid is drained out of the conduit.
Here and in the following reference is made to a 'siphon' provided in or at a conduit or at a condensate or washing water collector. Between the inlet and outlet of the conduit or between the two sides of the collector passage or opening, a pressure difference may exist or build up during operation of the apparatus. In particular when the process air is circulating through the process air loop (including through the laundry treatment cabinet and the fluff filter and in embodiments through a heat exchanger (e.g. evaporator and/or condenser of a heat pump system)), a pressure drop may arise (increasing for example with processing time through the fluff filter and/or the laundry storing cabinet). When for example no liquid is actively conveyed through the conduit or when no siphon would be provided at the outlet or opening of the collector, the air pressure difference may cause an air flow through the passage or conduit. Thereby ambient air may be drawn into the otherwise closed process air loop or process air may be exhausted to the outside or the intended process air path is bypassed (e.g. around the fluff filter or the evaporator). Therefore the siphon is provided in or at the conduit or passage such that it is filled with water (condensate or washing liquid) so that the pressure difference can not remove the water sealing in the siphon and no air passes through the conduit or opening. Here and in the following the (or each or some of the siphons) is replaced by a 1 -way valve that is closed in the inactivated state (no control signal from control unit to open the valve) or is replaced by a check or back-pressure valve for preventing air flow due to a pressure difference.
In an embodiment, the laundry treatment apparatus further comprises a controllable draining directing means such that the liquid conveyed from the washing liquid collector is selectively and controllably directed to a drain outlet for draining the liquid to the exterior of the apparatus cabinet and/or to the removable tank removably installed in the apparatus cabinet.
In an embodiment, the laundry treatment apparatus further comprises an intermediate tank for storing condensate for fluff filter washing, a condensate pump, and a washing pump. The condensate pump is arranged in liquid connection to the condensate collector and adapted to convey the collected condensate into the intermediate tank for storing condensate for fluff filter washing. The washing pump is arranged in liquid connection to the intermediate tank and adapted to convey stored condensate from the intermediate tank to the fluff filter for washing at least a portion of the filter surface by removing fluff.
Preferably, the laundry treatment apparatus further comprises a washing liquid outlet and/or a nozzle for applying the washing liquid to the fluff filter, a conduit connecting the washing pump and the nozzle, and a siphon formed in the conduit for avoiding the liquid flow before the pump is started and also for preventing compensation of an air pressure difference across the conduit. Alternatively or additionally the siphon is designed such as to interrupt the liquid flow from the intermediate tank to the washing liquid outlet and/or nozzle after deactivating the washing pump. pump is connected by a conduit to an inlet of the intermediate tank.
Preferably, the condensate collector is arranged in a base unit of the laundry treatment apparatus. Preferably, the washing liquid collector is arranged in the base unit of the laundry treatment apparatus.
Preferably, a removable tank housing of the removable tank comprises an overflow passage fluidly connected to the washing liquid collector via an overflow conduit for conveying to the washing liquid collector excess of condensate overflowing from the removable tank.
In an embodiment, a or the intermediate tank has an overflow passage and optionally a flow guiding element such that excess condensate flows from the intermediate tank to the washing liquid collector and/or to a or the removable tank and/or to the condensate collector. In an embodiment, the condensate collector has an overflow passage and optionally a flow guiding element such that excess condensate flows from the condensate collector to the washing liquid collector and/or to a or the removable tank.
In an embodiment, the outlet of a or the washing pump is connected by a conduit to a washing outlet and/or nozzle for applying the condensate onto the filter surface.
In an embodiment, the draining pump and/or the condensate pump and/or a or the washing pump is a high conveyance rate pump and/or a centrifugal pump.
Preferably the centrifugal pump is designed to have a spacing between an inner wall of the pump body and the outer extension of the conveying blades such that the spacing enables solid contaminants to pass from the pump inlet to the pump outlet between the conveying blades.
Reference is made in detail to preferred embodiments of the invention, examples of which are illustrated in the accompanying figures, which show:

Fig. 1: a perspective side view of a laundry treatment apparatus,
Figs. 2a, 2b, 2c,: schematic views of different embodiments of a laundry treatment apparatus and some of the components thereof in different arrangements or configurations,
Figs. 3, 4, 5: further schematic views of further embodiments of a laundry treatment apparatus with different arrangements or configurations of some of the components,
Fig. 6a: a perspective front view of the base unit in an embodiment of a laundry treatment apparatus,
Fig. 6b: a perspective front view of a collector cover,
Fig. 6c: a sectional view of the basement from apparatus front (right side in figure) to apparatus rear (left side of figure) through a condensate collector,
Fig. 6d: a sectional view of the basement from apparatus front (right side) to apparatus rear (left side) through a washing liquid collector which is in front (with respect to the drawing plane) of the condensate collector shown in Fig. 6c,
Fig. 7: a perspective rear view of the base unit in an embodiment of a laundry treatment apparatus,
Fig. 8a: another perspective front view of the base unit in an embodiment of a laundry treatment apparatus,
Fig. 8b: another perspective rear view of the base unit in an embodiment of a laundry treatment apparatus,
Fig. 9: a perspective rear view of an embodiment of a laundry treatment apparatus,
Fig. 10: a perspective front view of another embodiment of a base unit in a laundry treatment apparatus,
Fig. 11: another perspective front view of the embodiment of the base unit shown in Fig. 10,
Fig. 12a: a perspective view of an embodiment of a high conveyance rate pump,
Fig. 12b: a sectional view of the high conveyance rate pump, and
Fig. 12c: a sectional view of another embodiment of a high conveyance rate pump.

The following figures are not drawn to scale and are provided for illustrative purposes.
Fig. 1 shows a perspective side view of a laundry treatment apparatus 2 - in this arrangement a heat pump tumble dryer - with an apparatus cabinet 3 and comprising a base unit 30 above which a laundry drum 4 is arranged. The laundry treatment apparatus 2 is a front-loading type, i.e. a loading opening 6 for loading laundry into the drum 4 is provided at a front face of the apparatus 2 that can be covered and closed by a loading door 5 shown in the opened state.
A heat exchanger 38 for cooling process air downstream the drum 4 is arranged within the base unit 30. A filter arrangement 10 (shown partially removed) is adapted to filter process air. In the embodiment shown, it is arranged at the loading opening 6 in a section of the process air channel 24 downstream the drum 4 and upstream the heat exchanger 38. Process air from the drum 4 is guided through the filter arrangement 10, whereby fluff is removed from the process air flow. The filtered process air is conveyed through the process air channel section 24 downstream the filter arrangement 10 towards the heat exchanger 38 to be cooled down, i.e. to remove moisture from the process air which condensates at the heat exchanger 38. The liquid condensed at the heat exchanger is collected in the condensate collector 32 (see Fig. 2a). In this particular embodiment of a heat pump tumble dryer a second heat exchanger (not shown) is provided downstream the heat exchanger 38 for heating the process air before the heated process air is reintroduced into the laundry drum 4.
In Fig. 1, a front portion of the base unit 30 is opened by opening a base panel door 15 and opening a removable cover 14 arranged behind the base panel door 15 to allow a view of the heat exchanger 38 and a section 24 of the process air channel which is upstream the heat exchanger 38 and downstream the filter arrangement 10. The removable or pivotably attached cover 14 (compare also Fig. 7) is adapted to cover and close the opening at that part of the process air channel section to allow inspection and service of the heat exchanger 38 and/or other components such as a fluff filter 36 according to another embodiment (see below).
In the embodiment depicted in Fig. 2a, the fluff filter 36 is arranged in the base unit in the process air flow A upstream the heat exchanger 38 and downstream the process air channel section 24. Preferably in these embodiments where the fluff filter 36 is arranged close in front of the heat exchanger 38, no filter arrangement 10 as the one in the embodiment of Fig. 1 is provided (here Fig. 1 is provided for illustrative purposes showing the typical exterior of the apparatus).
Fig. 2a is a schematic view of an embodiment of the laundry treatment apparatus 2 comprising the apparatus cabinet 3, a control unit 16, the laundry treatment chamber 8, a process air circuit (a section 24 of which is shown in Fig. 1), the heat exchanger 38, a condensate collector 32, the fluff filter 36, the optional filter arrangement 10, a condensate pump 52, and a washing liquid collector 34. The control unit 16 is for controlling the operation of the apparatus 2, e.g. according to at least one predetermined laundry treatment program selected by the user. The laundry to be treated is stored inside the laundry treatment chamber 8, which may be formed as a drum 4 rotatable around a horizontal axis and being accessible through a loading opening 6.
The process air circuit circulates a flow of process air A which passes through the laundry inside the laundry drum. In this embodiment a process air fan (not shown) is arranged in a rear section of the process air circuit and is adapted to create the process air flow. From the laundry treatment chamber 8, the process air A is guided through the process air channel section 24 with the optional filter arrangement 10 that can remove fluff from the air flow. The process air A then passes through the fluff filter 36 for removal of (remaining) fluff before reaching the heat exchanger 38 by which it is cooled down. Due to the below described fluff filter washing arrangement the filter arrangement 10 is not required and all fluff can efficiently be filtered using the fluff filter 36 as single fluff filter.
At the heat exchanger 38, part of the humidity carried by the process air stream condenses creating a condensate C that is collected in the condensate collector 32. Downstream of the heat exchanger 38, the dried flow of process air A is heated. In the heat-pump type laundry dryer or washer heating of the process air is provided by the second heat exchanger 40 (condenser). In a condensation-type laundry dryer or washer-dryer the process air is heated by an electric heater arranged in the process air circuit downstream the first heat exchanger 38. Downstream the heater the process air is then guided back to the laundry treatment chamber 8.
The condensate pump 52 is arranged in liquid connection to the condensate collector 32 and adapted to provide the condensate to the fluff filter 36 for washing at least a portion of the filter 36. Preferably, the condensate pump 52 is a high conveyance rate pump, preferably comprising a rotor as described below. Here and in the following the terms "high conveyance rate pump" and "high flow rate pump" are used to denote a pump arranged for conveying a liquid at a minimum pumping rate of preferably 20 l/min or above.
In an embodiment, a liquid conduit 66 is arranged for guiding the condensate from the outlet of the condensate pump 52 to a washing outlet or washing nozzle where it is conveyed as a washing liquid L to the fluff filter 36. After washing the filter 36 (or at least a portion of it), the washing liquid L is collected in the washing liquid collector 34. The fluff filter 36 and the washing liquid collector 34 are arranged such that the washing liquid flows along at least a portion of the surface of the fluff filter and carries fluff washed off from the surface into the washing liquid collector 34. The washing liquid collector is adapted to collect the contaminated washing liquid.
Preferably, the fluff filter 36 is arranged such that the washing liquid L is flowing along the surface of the filter from where the washing liquid is applied and such that no or only very little washing liquid L passes through the fluff filter. In addition or alternatively, the washing outlet/nozzle 68 is arranged relative to the fluff filter 36 in such a way that the washing liquid L is applied to that side of the fluff filter 36 which is exposed to the fluff transported in the process air A and/or in such a way that no or only very little washing liquid L passes through the filter 36.
In the depicted embodiment the laundry treatment apparatus further comprises a drain pump 72 in liquid connection to the washing liquid collector 34 for conveying the contaminated washing liquid L to a drain outlet 74. Preferably, the drain pump 72 is a high flow rate pump, preferably comprising a rotor (see also below). The drain outlet 74 is adapted to drain the contaminated washing liquid L to a contaminated washing liquid sink such as a removable tank 12 as shown in Fig. 2a and/or to the exterior of the apparatus cabinet. In the latter case a liquid conduit may be provided at the outside of the cabinet for guiding the washing liquid to the user's home sink and/or another means for dirty water removal. Preferably, a drain conduit 73 is arranged for directing the contaminated washing liquid from the outlet of the drain pump 72 to the drain outlet 74. Preferably, the conduit comprises a siphon 73a (implementation e.g. as shown in Fig. 9) adapted to compensate potential pressure differences between the removable tank 12 and the outlet of the draining pump 72 and/or the washing liquid collector 34 when the draining pump is inactive.
In an embodiment, the filter arrangement 10 is removable so that it can be cleaned by the user and clogging of the process air circuit by fluff in the filter arrangement can be avoided. If optionally provided, the filter arrangement 10 is adapted for removing larger fluff components from the process air before the process air reaches the fluff filter 36 where remaining fluff is filtered. Preferably the fluff filter 36 and/or the described washing mechanism are adapted to also remove larger fluff components so that the filter arrangement 10 is not needed. Such a design is particularly beneficial as it does not need cleaning of the filter arrangement by the user, it is simpler, and/or reduces production and/or operating costs of the laundry treatment apparatus. The filter arrangement 10 is not shown in the embodiment depicted by the following figures. Nevertheless a skilled person will notice that it can equally be applied in any one of these embodiments as appropriate. In such embodiments in which fluff filter 10 is not used, preferably a fixed or removable grill will lie in its place at the inlet to the process air channel at the loading opening 6 to prevent laundry and foreign objects to fall into the process air channel and reach the washing liquid collector.
The embodiment shown in Fig. 2b additionally (as compared to Fig. 2a) comprises a condensate directing means 54, e.g. valve, that receives the condensate C from the condensate pump 52 and directs it either to the fluff filter 36 for washing at least a portion of the fluff filter surface or to a condensate sink. The condensate directing means 54 is controlled by the control unit 16, preferably through control signals sent from the control unit 16 to the condensate directing means 54 on a control signal line 18. Preferably, the condensate sink is the washing liquid collector 34 (as in the embodiment shown in Fig. 2b) and/or the removable tank 12 and/or an overflow passage 76 thereof and/or an external outlet for draining condensate to the exterior of the apparatus cabinet. Preferably, a liquid conduit 58 connects an outlet of the condensate directing means 54 to the condensate sink, here the washing liquid collector 34. A siphon 58a may be arranged in the liquid conduit 58 in order to prevent an air flow through the conduit 58 due to a pressure difference between the inlet and outlet of the conduit and/or to stop the condensate flow from the condensate collector 32 through the condensate directing means 54 and the conduit 58 to the condensate sink when the condensate pump is inactive. In addition or alternatively, the condensate directing means is designed to fluidly seal off the inlet of the condensate directing means 54 from the outlet directing condensate to the the conduit 66. I.e. in its default or non-activated position the condensate directing means 54 seals off the passage towards the conduit 66. Alternatively or additionally a siphon or 1-way valve placed downstream to the directing means 54 is provided to seal off the passage towards or through the conduit 66.
Alternatively or in addition to the condensate directing means 54, the laundry treatment apparatus may comprise a direct condensate overflow 33 as shown in Fig. 3 for draining excess condensate from the condensate collector 32 to the washing liquid collector 34. Preferably the condensate overflow 33 comprises a siphon (not shown), e.g. for compensating pressure differences between the condensate collector 32 and the washing liquid collector 34. The condensate overflow allows excess condensate in the condensate collector to pass from the condensate collector to the washing liquid collector. Allowing excess condensate to leave the condensate collector and pass to the washing liquid collector helps to reduce operating noise of the laundry treatment apparatus, because the condensate pump does not need to be activated even when the condensate collector is full. Moreover no fluff filter washing for removing the condensate from condensate collector 32 is required when there is excessive condensate and no need for filter washing.
Preferably, the fluff filter 36 is washed before it is clogged by fluff transported in the process air flow. Preferably, the fluff filter 36 is washed at the beginning or at the end of a laundry treatment program or sub-program. More preferably, washing the fluff filter 36 is avoided during an ongoing or running laundry treatment program or sub-program that requires drying of the process air flow, because washing the fluff filter 36 wets the filter whereby extra humidity is added to the process air A passing through it. Thus, incorporating a condensate directing means 54 and/or a condensate overflow 33 is particularly beneficial because it enables draining or partial draining of the condensate collector 32 when the condensate collector is full without the need of conveying condensate to (i.e. washing) the fluff filter 36.
As described above, the condensate sink to which a condensate directing means 54 can direct the condensate C received from the condensate pump 52 may be the removable tank 12 as shown schematically in Fig. 4. A liquid conduit 58 serves for guiding the condensate C from the condensate directing means 54 to the removable tank 12, more particularly the condensate is supplied to the removable tank housing from which the water flows spontaneously to the washing liquid collector or is supplied to an overflow passage of the removable tank. A siphon 58a is preferably arranged in the conduit 58 in order to compensate pressure differences between the condensate collector 32 and the removable tank 12 and/or the overflow passage 76 and/or in order to interrupt liquid flow from the condensate collector 32 to the removable tank and/or the overflow passage 76 when the condensate pump 72 is stopped. An overflow conduit 78 is arranged to guide liquid from the removable tank overflow passage 76 to the washing liquid collector 34 and/or to another liquid sink such as an outlet at the apparatus cabinet and/or an external tank. Preferably, a siphon 78a is arranged in the overflow conduit 78 in order to compensate pressure differences between the overflow passage 76 and the washing liquid collector 34 and/or another liquid sink and/or to interrupt liquid flow from the overflow passage 76 to the washing liquid collector 34 and/or another liquid sink. Although only shown in some of the embodiments, the overflow passage 76 and its arrangement at the bottom of the housing 75 of the removable tank 12 can be provided in each of the other embodiments.
Fig. 2c schematically depicts an embodiment of a laundry treatment apparatus 2 further comprising an intermediate tank 60 adapted for intermediate storage of condensate C and a washing pump 64 for conveying the condensate from the intermediate tank to the fluff filter 36 for fluff filter washing. The condensate pump 52 pumps the condensate C from the condensate collector to the intermediate tank 60 through a liquid conduit 56 connecting the outlet of the condensate pump 52 and an inlet 61 of the intermediate tank. Preferably the intermediate tank comprises an overflow passage 62 from where excess condensate can be drained to a sink, e.g. the washing liquid collector 34, when the intermediate tank 60 is full. A flow guiding element 63 is arranged for directing the excess condensate from the overflow passage 62 to the sink.
When the fluff filter 36 is to be washed, the washing pump 64 which is fluidly connected to the intermediate tank 60 conveys liquid from the intermediate tank 60 through a conduit 66 to the washing outlet/nozzle 68 from where it is applied to the fluff filter 36 for washing at least a portion of the fluff filter surface. Preferably, the washing pump 64 is a high flow rate pump. In such an embodiment, the condensate pump 52 may be a smaller pump, preferably with a maximum pumping rate below 25 l/min. The condensate pump 52 may be adjusted to create only very little operating noise, thus reducing the overall noise level of the laundry treatment apparatus 2. In order to prevent spontaneous flowing of water from the intermediate tank 60 to the nozzle 68 before the washing pump 64 becomes active and/or to interrupt the flow of condensate from the intermediate tank 60 through the liquid conduit 66 to the washing outlet/nozzle 68 when the washing pump becomes inactive, a siphon 66a may be arranged in the conduit 66.
Fig. 5 is a schematic view of a further embodiment of a laundry treatment apparatus 2. It differs from the embodiments shown in Figs. 2, 3, and 4 in that the drain pump 72 is arranged close to the fluff filter 36, namely at or close to the front of the apparatus 2, more precisely the front of the base unit 30. In this arrangement the shorter distance between the fluff filter 36 and the drain pump 72 allows a more compact layout of the washing liquid collector 34 with shorter liquid channels which in turn results in a more efficient draining of the collector 34 with better removal of the contaminated washing liquid L and the fluff contained therein.
In the embodiments shown in Figs. 3 and 5 the overflow 76 which is provided in the housing 75 of the removable tank 12 guides excess liquid that spills out from the removable tank 12 into the housing 75 to the washing liquid collector 34 and/or to the exterior of the apparatus cabinet when the removable tank 12 is full. This arrangement of tank housing 75 and overflow 76 is also applicable to the other embodiments of a laundry treatment apparatus described herein, and in particular to the embodiments depicted in Figs. 2 and 4.
Fig. 6a is a perspective front view of an embodiment of the base unit 30 of a disassembled laundry treatment apparatus 2 showing the condensate collector 32 and the washing liquid collector 34. The condensate collector 32 and the washing liquid collector 34 are separated by means of a separating wall 106. During and after filter washing, the contaminated washing liquid L from the fluff filter 36 reaches a front section 34a of the washing liquid collector 34 from where it is guided by a channeling section 34b to a pump section 34c located at the rear side of the base unit 30. The condensate C produced at the heat exchanger 38 of the assembled apparatus is collected in a condensate collector main section 32a of the condensate collector and flows from there to a condensate collector pump section 32b. Further, a process air fan casing 120 is arranged for attachment of a process air fan (not shown).
Fig. 6b is a perspective front view of a collector cover 110. It is adapted to be placed on top of the condensate collector 32 and the washing liquid collector 34 in the base unit 30 shown in Fig. 6a as indicated by the arrow below the figure. It may comprise a condensate well 112 for guiding condensate C received from the heat exchanger 38 to a condensate passage 114 and therethrough to the condensate collector 32. The condensate well 112 may be limited by a containment wall 117 arranged for avoiding condensate to reach downstream sections of the process air circuit, in particular the condenser 40 for heating the process air A or the process air fan. The positioning of the condensate passage 114 is adjusted so that condensate is directed to the condensate collector. The collector cover 110 and/or the condensate well 112 may be sloped so as to guide the condensate C towards the condensate passage 114. The collector cover 110 may further comprise a process air guidance 118 for guiding process air A from the heat exchanger 38 (not shown) to the process air fan (not shown) in the process air fan casing 120.
As can be seen from the sectional view along the condensate collector 32 depicted in Fig. 6c and the sectional view along the washing liquid collector 34 depicted in Fig. 6d, the base unit 30 is preferably arranged so that

at least the floor of the main section 32a of the condensate collector is sloped so that condensate C in the condensate collector 32 is directed towards the pump section 32b of the condensate collector; and/or
at least the floor of the channeling section 34b and/or the floor of the front section 34a of the washing liquid collector is sloped so that washing liquid L in the washing liquid collector 34 is directed towards the pump section 34c of the washing liquid collector.

Preferably, the slopes in the condensate collector 32 and/or the washing liquid collector 34 are adjusted so that the liquid in the respective collector flows into the corresponding pump section at a sufficiently high flow rate to make sure that condensate or washing liquid is primarily supplied to the condensate pump 52 and/or the washing liquid pump 72 and at a flow rate such that liquid contaminations such as fluff in the washing liquid are reliably transported together with the liquid. Furthermore, the slopes in the condensate collector 32 and/or the washing liquid collector 34 may be adjusted so that the liquid in the respective collector is directed towards the corresponding pump section even when the laundry treatment apparatus 2 is not installed on a perfectly horizontal surface.
Fig. 7 is a perspective rear view of the base unit 30 as shown in Fig. 6a, but with an attached collector cover 110 according to Fig. 6b. In addition, also the condensate pump 52, the drain pump 72, the fluff filter 36, and the removable cover 14 are shown assembled in this view. Preferably, the removable cover 14 is adapted to cover the process air channel section upstream of the fluff filter during laundry treatment and to allow inspection and service of the heat exchanger 38 (removed in this figure) and/or the fluff filter 36. The condensate well 112, the condensate passage, the process air guidance 118, and the process air fan casing 120 have been described above. Preferably, the condensate pump 52 is in liquid connection to the condensate collector 32, and the drain pump 72 is in liquid connection to the washing liquid collector 34 (see e.g. Figs. 2, 3, 4).
Fig. 8a shows a perspective front view and Fig. 8b a perspective rear view of the base unit 30 depicted in Fig. 7 after assembly of the following additional components:

the process air channel section 24,
the heat exchanger 38 (not visible, below the cover 122),
a cover 122 arranged for covering the heat exchanger 38 and forming the sections of the process air channel between the fluff filter and the process air fan casing 120 (cover 122 covers the so called battery channel of a heat-pump type basement in which the evaporator and condenser are arranged), and
a conduit 66 arranged for guiding condensate to a washing outlet and/or washing nozzle 68.

In an embodiment, the conduit 66 is attached to the outlet of the condensate pump 52 and guides condensate from the condensate pump directly to the washing outlet and/or washing nozzle 68 as shown, e.g., in the schematic view of Fig. 2a. In another embodiment, the conduit 66 is attached to a condensate directing means 54 (not shown), e.g., according to the schematic view of Fig. 2b. Preferably, the condensate directing means 54 may be located adjacent to the condensate pump 52 or may be integrated into the housing of the condensate pump 52.
Fig. 9 is a perspective rear view of an embodiment of an embodiment of the laundry treatment apparatus 2 in an apparatus cabinet 3. Apart from the components of the base unit 30 that have been described above, the figure also shows the drain conduit 73, preferably comprising the siphon 73a, connected to the outlet of the drain pump 72 and adapted for directing washing liquid conveyed by the drain pump to an upper part of the apparatus 2, preferably to the drain outlet 74, preferably located at or in the removable tank 12 or at or in an overflow passage 76 of the removable tank. In the embodiment, the drain pump 72 is located at the rear side of the laundry treatment apparatus 2 (cf. the schematic views of Figs. 2, 3, and 4). A process air fan back cover 121 forms the rear part of the process air fan casing 120 and a section of the process air channel guiding process air A from the process air fan to the laundry treatment chamber.
A perspective front view of another embodiment of the base unit 30 of a disassembled laundry treatment apparatus 2 is depicted in Fig. 10. As compared to the embodiment of Fig. 6a, the washing liquid collector preferably comprises the front section 34a and the pump section 34c both located at or close to the front side of the base unit 30. Preferably, the pump section 34c of the washing liquid collector is in liquid connection to the drain pump 72 also located at or close to the front side of the base unit 30. During and after filter washing, the contaminated washing liquid L from the fluff filter 36 reaches the front section 34a of the washing liquid collector 34 from where it is directly guided to the pump section 34c. As can be seen, the length and/or the average length and/or the slope and/or the average slope of the path to be covered by the contaminated washing liquid from the front section 34a to the pump section 34c is substantially shorter in this embodiment than in the embodiment according to Fig. 6a. As a result, contaminated washing liquid L and the fluff contained therein can be removed more efficiently from the washing liquid collector 34 by the draining pump 72. Furthermore, in this embodiment, the condensate collector 32 comprises the main section 32a and the pump section 32b may span a larger portion of the base area of the base unit 30 than in the embodiment shown in Fig. 6a, because the channel section 34b of the washing liquid collector 34 for directing washing liquid L to the rear side of the base unit 30 is not needed. The condensate pump 52 is in liquid connection to the pump section 32 of the condensate collector. The process air fan casing 120 is arranged for attachment of the process air fan (not shown).
As compared to Fig. 10, the perspective front view of Fig. 11 additionally shows the components:

the collector cover 110 similar to the one shown in Fig. 6b arranged for covering the condensate collector 32,
the drain conduit 73, preferably comprising the siphon 73a, attached to the outlet of the drain pump 72 and adapted to guide contaminated washing liquid L from the washing liquid collector 34 to the drain outlet 74.

Preferably, the collector cover 110 comprises the condensate well 112 adjusted to guide condensate C received from the heat exchanger 38 to the condensate passage 114 and from there to the condensate collector 32. In the embodiment of Fig. 11, the collector cover 110 also comprises the process air guidance arranged for guiding process air A from the heat exchanger 38 to the process air fan (not shown) arranged in the process air fan casing 120.
As described above, the condensate pump 52 and/or the drain pump 72 preferably are high flow rate pumps, i.e. arranged for a minimum liquid pumping rate of 20 l/min or above. A perspective view of an embodiment of an example for a high flow rate pump 200 is shown in Fig. 12a. It comprises a liquid inlet 204, a liquid outlet 218, and a motor unit 220 with a power plug 222. Preferably, the pump is activated by supplying electrical power to the power plug 222. When the pump is active, the motor unit 220 drives an internal pump rotor 206 (see below) which causes liquid to be conveyed from the liquid inlet 204 to the liquid outlet 218.
Fig. 12b is a sectional view of the embodiment of the high flow rate pump 200 shown in Fig. 12a. Apart from the components described above, it depicts a suction well 202 arranged for providing the liquid to be conveyed by the pump 200 and the internal pump rotor 206 driven by the motor unit 220. When power is provided to the motor unit 220 via the power plug 222, the pump rotor 206 rotates and creates a centrifugal acceleration in the surrounding liquid volume, whereby the liquid is pushed in a direction perpendicular to the rotor axis into the liquid channel 216, resulting in a liquid flow as indicated by the arrow. Preferably, the outer edges of the blades of the pump rotor 206 do not contact the pump chamber walls 208, but are (at least laterally and at the suction side) separated from the pump chamber walls 208 by a certain distance "b". In the embodiment, the bottom edges of the rotor blades are also separated from the pump inlet 204 by a certain distance "a" and are inclined at an angle "α" with respect to the direction of liquid flow. Preferably, the distances "a" and "b" and the angle "α" are adjusted so that particles contaminating the liquid (e.g. fluff in the contaminated washing liquid) can easily pass the rotor without blocking it and thus are conveyed together with the liquid. Preferably, the distances "a" and/or "b" are at least 5 mm. Preferably, the liquid inlet 204 has a circular shape with an opening diameter of at least 15 mm. More preferably, the liquid channel 216 and/or the liquid outlet 218 have a circular cross section with a diameter of at least 15 mm. More preferably, the distance between the liquid inlet 204 and the floor of the suction well 202 is at least 5 mm. Furthermore, the pump rotor 206 may comprise a disk at the shaft to the motor so as to avoid fabric to enter the motor and/or block the shaft. As an advantage of the described design, the high flow rate pump 200 does not get clogged by contaminations of the liquid and is able to convey liquid with or without contaminations at high pumping rates.

Fig. 12c is a sectional view of another embodiment of a high flow rate pump 200. In difference to the embodiments of Figs. 12a and 12b, the outlet direction is not vertical but horizontal, because the liquid channel 216 is not bent upwards.

Reference Numeral List:

2	laundry treatment apparatus	58a	siphon
3	apparatus cabinet	60	intermediate tank
4	drum	61	intermediate tank inlet
5	loading door	62	intermediate tank overflow passage
6	loading opening	63	flow guiding element
8	laundry treatment chamber	64	washing pump
10	filter arrangement	66	conduit
12	removable tank	66a	siphon
14	removable cover	68	washing outlet/nozzle
15	base panel cover	72	drain pump
16	control unit	73	drain conduit
18	control signal line	73a	siphon
		74	drain outlet
24	process air channel section	75	removable tank housing
30	base unit	76	removable tank overflow (outlet)
32	condensate collector
32a	main section of condensate collector	78	overflow conduit
32b	pump section of condensate collector	78a	siphon
33	condensate overflow	106	separating wall
34	washing liquid collector	110	collector cover
34a	front section of washing liquid collector	112	condensate well
34b	channeling section of washing liquid collector	114	condensate passage
34c	pump section of washing liquid collector	117	containment wall
36	fluff filter	118	process air guidance
38	heat exchanger (evaporator)	120	process air fan casing
40	second heat exchanger (condenser)	121	process air fan back cover
52	condensate pump	122	cover
54	condensate directing means	200	high flow rate pump
56, 58	conduit	202	suction well
		204	liquid inlet
		206	pump rotor
		208	pump chamber wall
		216	liquid channel
		218	liquid outlet
220	motor unit	C	condensate
222	power plug	L	washing liquid
A	process air

Claims

Laundry treatment apparatus (2), in particular dryer, condensate dryer or heat pump tumble dryer, the apparatus (2) comprising:
a control unit (16) for controlling the operation of the laundry treatment apparatus,

an apparatus cabinet (3),

a laundry treatment chamber (8) for treating laundry using process air (A),

a process air circuit for circulating the process air (A),

a heat exchanger (38) arranged in the process air circuit for cooling the process air (A) and condensing humidity from the process air,

a condensate collector (32) assigned to the heat exchanger (38) for collecting condensate (C) condensed at the heat exchanger,

a fluff filter (36) arranged in the process air circuit upstream the heat exchanger (38) for filtering fluff from the process air (A) passing the fluff filter,

a condensate pump (52) in liquid connection to the condensate collector (32) and being adapted to convey the condensate (C),

a condensate directing means (54) receiving the condensate (C) pumped by the condensate pump (52) and for selectively directing the condensate flow under the control of the control unit (16)
a) to a conduit guiding the condensate flow towards the fluff filter (36) for washing at least a portion of the filter surface by removing fluff, or

b) to a condensate sink;

characterized by

a washing liquid collector (34) assigned to the fluff filter (36) and being adapted to collect washing liquid (L) from the fluff filter,

wherein the fluff filter (36) and the washing liquid collector (34) are arranged such that the washing liquid (L) flows along at least a portion of the surface of the fluff filter (36) and carries fluff washed off from the surface into the washing liquid collector (34) which is adapted to collect the washing liquid (L) contaminated with fluff,

wherein the washing liquid collector (34) is separate from the condensate collector (32),

wherein the condensate collector (32) exclusively collects condensate from the heat exchanger (38) and receives no or essentially no washing liquid from filter washing, and

wherein the fluff filter (36) is positioned within a process air channel section which is located in one or more of:
a bottom region within the apparatus cabinet (3), and

the basement (30) of the apparatus.
Laundry treatment apparatus (2) according to claim 1, wherein the fluff filter (36) is designed such that the washing liquid (L) is flowing along the surface of the filter (36) to which the washing liquid is applied and such that no or substantially no washing liquid (L) is passing through the fluff filter (36), or
wherein the or a nozzle (68) for applying the washing liquid (L) to the fluff filter (36) is arranged relative to the fluff filter such that the washing liquid (L) is applied at that side of the fluff filter (36) which is exposed to the fluff transported in the process air (A) from the laundry treatment chamber (8).
Laundry treatment apparatus (2) according to any of the previous claims, further comprising a drain pump (72) in liquid connection to the washing liquid collector (34) to convey the contaminated washing liquid (L) to a drain outlet (74) for draining the contaminated washing liquid (L) to a contaminated washing liquid sink.
Laundry treatment apparatus (2) according to claim 3, wherein the drain pump (72) is arranged either between a process air fan or a cooling air fan and a front wall of the apparatus cabinet (3) or between a heat pump refrigerant compressor and a front wall of the apparatus cabinet (3).
Laundry treatment apparatus (2) according to any of the previous claims, wherein the outlet of the condensate directing means (54) which directs the condensate flow towards the condensate sink is connected to an inlet of a conduit (58), wherein the conduit (58) has an outlet and wherein a siphon (58a) is arranged in the conduit between the inlet and outlet such as to avoid airflow through the conduit due to an air pressure difference between the ends of the conduit.
Laundry treatment apparatus (2) according to any of the previous claims, further comprising a controllable draining directing means such that the liquid (L) conveyed from the washing liquid collector (34) is selectively and controllably directed to a drain outlet for draining the liquid (L) to the exterior of the apparatus cabinet or to a removable tank (12).
Laundry treatment apparatus (2) according to any of the previous claims, further comprising an intermediate tank (60) for storing condensate (C) for fluff filter washing, the condensate pump (52) in liquid connection to the condensate collector (32) and being adapted to convey the collected condensate (C) into the intermediate tank (60),
a washing pump (64) in liquid connection to the intermediate tank (60) and being adapted to convey the stored condensate (C) to the fluff filter (36) for washing at least a portion of the filter surface by removing fluff.
Laundry treatment apparatus (2) according to claim 7, further comprising a nozzle (68) for applying the washing liquid (L) to the fluff filter (36), a conduit (66) connecting the washing pump (64) and the nozzle (68), and optionally a siphon (66a) formed in the conduit (66) for avoiding an airflow through the conduit due to an air pressure difference between the ends of the conduit or for or for interrupting the liquid flow from the intermediate tank (60) to the nozzle (68) after deactivating or before activating the washing pump (64).
Laundry treatment apparatus (2) according to claim 7 or 8, wherein the outlet of the condensate pump (52) is connected by a conduit (56) to an inlet (61) of the intermediate tank (60).
Laundry treatment apparatus (2) according to any of the previous claims, wherein the condensate collector (32), the washing liquid collector (34) or the condensate and washing liquid collectors (32, 34) are arranged in a base unit (30) of the treatment apparatus (2).
Laundry treatment apparatus (2) according to any of the previous claims, wherein a or the intermediate tank (60) has an overflow passage (62) and optionally a flow guiding element (63) such that excess condensate (C) flows from the intermediate tank (60) to the washing liquid collector (34) or to a or the removable tank (12), or
wherein the condensate collector (32) has an overflow passage (33) and optionally a flow guiding element such that excess condensate (C) flows from the condensate collector (32) to the washing liquid collector (34) or to a or the removable tank (12).
Laundry treatment apparatus (2) according to any of the previous claims, wherein the outlet of a or the washing pump (64) is connected by a conduit (66) to a washing outlet or nozzle (68) for applying the condensate (C) onto the filter surface.
Laundry treatment apparatus (2) according to any of the previous claims, wherein a removable tank housing (75) of a or the removable tank (12) comprises an overflow passage (76) fluidly connected to the washing liquid collector (34) via an overflow conduit (78) for conveying to the washing liquid collector (34) excess of condensate overflowing from the removable tank (12).
Laundry treatment apparatus (2) according to any of the previous claims, wherein a or the drain pump (72) or the condensate pump (52) or a or the washing pump (64) is a high conveyance rate pump or a centrifugal pump.
Laundry treatment apparatus (2) according to claim 14, wherein the centrifugal pump has a spacing between an inner wall of the pump body and the outer extension of the conveying blades such that the spacing enables solid contaminants to pass from the pump inlet to the pump outlet between the conveying blades.