EP2314759B1

EP2314759B1 - Laundry dryer machine having a system for washing the drying air filter

Info

Publication number: EP2314759B1
Application number: EP09425414A
Authority: EP
Inventors: Silvano Fumagalli
Original assignee: Candy SpA
Current assignee: Candy SpA
Priority date: 2009-10-20
Filing date: 2009-10-20
Publication date: 2012-02-29
Anticipated expiration: 2029-10-20
Also published as: ATE547554T1; EP2314759A1

Abstract

The present invention concerns a laundry drying machine (11) comprising a drum (13) with a cavity (41) for receiving the laundry to be dried, heating means (14) for heating the drying air, a condenser (15) for removing moisture from the drying air and conveying means (16), for successively circulating the drying air through the drum (13), the condenser (15) and the heating means (14), the machine further comprising a collection container (32) for collecting the water condensed in the condenser (15) and a filter (26) for the drying air that exits from the drum (13). Said container (32) has at least one drain (75,175,275) for draining the water contained in the container (32) towards said filter (26).

Description

The present invention relates to a laundry dryer machine having a system for washing the drying air filter.
It is known in the art to provide laundry dryer machines comprising a rotary drum designed to internally receive the laundry to be dried, means for heating the drying air and a condenser for removing the moisture contained in the drying air exiting the rotary drum. These parts are arranged within a casing of the household appliance.
The machine also comprises a special fan which successively circulates the drying air through the drum, the condenser and the heating means (typically an electrical resistor) during operation of the apparatus.
The laundry dryer comprises a container for collecting condensed water, which can be typically removed from the household appliance to allow the user to drain the condensate at the end of a drying cycle.
When exiting from the drum, the drying air flow may carry impurities therein, such as fibers, threads, fluff, released from the laundry.
Prior art machines comprise a drying air filter downstream from the drum, which retains these air-borne impurities, and prevents them from being circulated within the machine.
With time, a large amount of impurities may build up in the filter, to such an extent as to impair normal operation of the machine and to require cleaning.
The prior European patent application EP 0.816.549 discloses a washer-dryer machine including a rotating drum and a filter for trapping the fluff freed during the drying process. The machine includes also a tank for collecting water for washing the filter and a tank for collecting the condensation. The machine provides for an automatic operation for cleaning the filter with the rinsing water or with the condensation water at the end of a drying stage.
In view of the above state of the art, the object of this invention is to provide a laundry dryer machine, which allows the filter to be maintained in a satisfactorily clean state, without requiring laborious maintenance or washing procedures.
A further object of the invention is to provide a machine having a simple and inexpensive structure.
Another object of the invention is to provide a machine that can also maintain the condenser in a satisfactorily clean state, without requiring laborious maintenance procedures.
According to the present invention, these objects are fulfilled by a laundry dryer machine that comprises a drum with a cavity for receiving the laundry to be dried, means for heating a drying air, a condenser for removing moisture from the drying air and conveying means, for successively circulating the drying air through the drum, the condenser and the heating means, the machine further comprising a container for collecting the water condensed in the condenser and a drying air filter, characterized in that said container has at least one drain for draining the water contained in the container towards said filter.
The features and advantages of the present invention will appear from the following detailed description of a few practical embodiments, which are given by way of example and without limitation with reference to the annexed drawings, in which:

Figure 1 is a perspective view of a laundry dryer machine of the invention, with some parts being omitted for a clearer vision of the internal components of the appliance,
Figure 2 is a front view of the container for collecting condensed water according to a first embodiment of the invention,
Figure 3 is a side view of the container for collecting condensed water as shown in Figure 2,
Figure 4 is a front view of a container for collecting condensed water according to a second alternative embodiment of the invention,
Figure 5 is a front view of a container for collecting condensed water according to a third alternative embodiment of the invention,
Figure 6 is an alternative embodiment of the drying air filter and its respective housing within the machine frame.

Referring now to Figures 1 to 3, a laundry dryer machine 11 is described, which comprises an outer casing 12, with a rotary drum 13, a condenser 15 and heating means 14 arranged therein.
The rotary drum 13 has a cavity 41 (Fig. 3) for receiving the laundry to be dried, and is rotated, in use, by known motor means.
The drum 13 has a front opening 50, through which the laundry may be loaded and unloaded from the drying cavity 41. The drum 13 has a substantially horizontal axis of rotation.
An opening is formed on the front of the casing 12, for the user to access the interior of the drum 13 therethrough. The opening can be closed by a door 39, preferably formed as a transparent window hinged to the casing 12 of the household appliance.
In use, the heating means 14 have the task of heating the drying air 24 circulating in the household appliance. Preferably, these means are made by an electrical resistor 14 placed on the back of the machine 12, i.e. on the side opposite to the window 39.
In use, the condenser 15 has the task of removing moisture from the drying air 24 exiting the drum 13 and may be formed per se according to the prior art. The condenser 15 is placed under the drum 13.
The laundry dryer 11 also comprises conveying means 16 for successively circulating the drying air through the rotary drum 13, the condenser 15 and the heating means 14. These conveying means preferably include a fan 16 placed downstream from the condenser 15 and upstream from the heating means 14.
The laundry dryer machine 11 also comprises a fan 17 for causing cooling air 19 to pass through the condenser 15, by introducing it into the casing of the household appliance through the inlet 18.
The machine 11 also comprises a drying air filter 26, downstream from the drum 13 and upstream from the condenser 15. Such filter 26 has the task of trapping any impurity carried by the drying air exiting the drum 13, such as fibers, lint or fluff released from the laundry during drying. The filter 26 is made of known filtering meshes, and has a substantially flat shape, vertically arranged close to a front wall of the machine.
A tank 30 is placed downstream from the condenser 13 for collecting condensed water, the latter being pumped towards a container 32 by the pump 31. Particularly, the pump 31 conveys the condensed water through the conduit 33 to a nozzle 34 located above a top opening 35 for filling the container 32.
The container 32 is designed to collect the condensed water and is located at the opening 50 of the drum 13, within an annular wall 53, 70 of the fixed frame of the machine. In use, the container 32 is preferably engaged in a frame 55 of the window 39 and, when the door 39 is closed, it remains within the casing 12.
The laundry dryer 11 comprises a passageway 51 for letting air out of the drum 13, that carries wet air towards the filter 26. The passageway 51 is preferably formed between a bottom wall of the container 32 and the wall 53 of the machine frame.
The container 32 comprises a filter 71 located below the inlet 35 for the condensed water.
Preferably, the laundry dryer 11 comprises control means, for controlling the various features and parts of the machine (rotation of the drum 13, heating by the resistor 14, operation of the fans 16, 17, etc.). The control means are associated with a user interface, which may include knobs and/or pushbuttons, that the user may access from the front of the household appliance to control their operation.
According to the present invention, the collection container 32 comprises at least one drain 75 for draining water through the filter 26.
Preferably, the drain 75 is made by of an opening formed on a bottom wall of the container 32, above the filter 26.
In one embodiment of the invention, the container 32 comprises a plurality of drain openings 75, arranged along the filter 26.
Preferably, the container 32 has means for feeding through the drain 75 a volume of water already collected in the container, thereby quickly lowering the level of water in the container to a predetermined height, lower than the maximum level that can be reached in the container 32.
The means for feeding a volume of water to the drain preferably comprise a valve 73, openable to put the inner volume of the container 32 in communication with the drain 75, thereby flushing the filter with a considerable volume of water.
The valve 73 has a closing member that can be moved by an actuator 74, of a type known per se.
Preferably, the drain 75 is formed in a conduit 76 located at the lower part of the container, and separated from the main inner volume of the container.
The valve 73 is driven by the control means of the laundry dryer machine.
The maximum volume of drained water is at least one sixth of the overall volume of the container 32, preferably at least one fourth of such overall volume.
The flow of flushing water passes through the filter 26 and cleans away impurity buildups appeared during the drying cycle, thereby actually washing the filter and ensuring proper operation of the machine, both during the final step of the current drying cycle and in the following drying cycle.
The flushing water flows by gravity through the condenser 15 located downstream from the filter, at a lower level, too. Thus, the drained water flows into the collection tank 30, where impurities are retained by a special filtering system upstream from the pump 31.
The container 32 also has an overflow conduit 72, which puts the interior volume of the container 32 in communication with the drain 75, particularly through the lower conduit 76. The overflow conduit 72 has a top opening that opens into the container and defines the maximum water volume in the container 32.
Figure 4 shows an alternative embodiment of the container 132, which replaces the above described container 32. The other components of the laundry dryer machine shall be intended to be unchanged from the first embodiment.
The container 132 has an overflow conduit 161 with a top opening 163 that puts it in communication with the interior of the container at a level close to the top end of the container. The opening 163 defines the maximum water level in the container 132.
The container 132 also has a second conduit 160 that communicates with the interior of the container 132 through a top opening 164, located at a level separate from and lower than the opening 163.
Both openings 163 and 164 may be equipped with a downwardly bent pipe portion, for drawing water at a level lower than the water surface in the container.
Both conduits 160 and 161 lead to the drain 175, which is formed in the bottom wall of the container 132. The conduits 160 and 161 are placed on opposite lateral sides of the container 132.
A valve comprising a closing member 162 is associated with the drain 175. Depending on the position of the closing member 162, the conduit 160 may be alternately put in communication with the drain 175 or be hydraulically separated from the drain.
Conversely, the conduit 161 is always in communication with the drain 175.
Preferably, the closing member 162 includes a plate rotating about a horizontal axis. In the position as shown in the figure, the closing member 162 is inclined to prevent water from flowing through the conduit 160 towards the drain 175. In this condition, water may be collected in the container 132 to reach the level defined by the opening 163. When the closing member 162 is moved to a horizontal position, the valve is opened and all the water above the opening 164 is discharged through the drain 175 for abruptly flushing the filter.
Figure 4 shows the maximum amount Q of water that may be drained by opening the closing member 162 when the container has reached its maximum capacity defined by the overflow 161.
The closing member may be driven manually, using suitable control members (not shown) that the user can access from outside the machine.
Figure 5 shows a third alternative embodiment of the condensed water collection container 232. The other parts of the laundry dryer machine are intended to be unchanged from the previous embodiments.
The container 232 comprises a plurality of drains 275 formed on the bottom wall of the container 232, at a conduit 276 that, in use, extends horizontally along the bottom wall of the container 232.
In this embodiment, the means for feeding water to the drain comprise a conduit which in turn comprises a first stationary part 280 and a second movable part 281 which moves relative to the first. The movable part 281 can slide vertically within the stationary part 280 while maintaining a hydraulic seal between the two parts.
The stationary part 280 is connected to the conduit 276.
The movable part 281 has a top opening 282 that defines the maximum water level in the container 232. The control member 262, preferably a rod projecting out of the top of the container 232, is fixed to the movable part 281.
Acting upon the rod 262, the level of the opening 282 may be changed, i.e. moved to the position designated by 282a, in which the movable part 281 is caused to slide downwards in the stationary part 280 of the conduit (position 281a).
Thus, the water above the opening 282a is discharged through the conduit 280 and the drain 275, to wash the filter 26.
The rod 262 may be manually driven and be possibly connected to control members (not shown) accessible to the user.
In Figure 5, "Q" designates the level of water that is discharged when the movable part of the conduit is moved from the position 281 to the position 281a.
Figure 6 shows an alternative embodiment 326 of the drying air filter at the exit of the drum 13, and its housing within the frame of the machine.
Particularly, the filter 326 has a greater thickness and has a first filtering mesh 393 and a second filtering mesh 394 finer than the first.
The filter 326 has a bottom door 392 that can be opened to ease cleaning of the filter.
The filter housing is widened between the two walls 390 and 391 of the machine framework. Particularly, the wall 391 is formed with a specially conceived concavity, for receiving the filter of larger size.
Preferably, condensed water drainage may be controlled by the control means to occur at the end of the drying cycle, so that condensed water may release its heat to the drying cavity 41, for a long time during normal operation of the machine.
The container 32, 132, 232 is preferably formed of transparent materials, so that the user can check the load and the container filling state.
The above clearly shows that the objects of the present invention have been fulfilled.
Particularly, a laundry drying machine has been provided, which can easily and quickly maintain the drying air filter in a satisfactorily clean state, without requiring any laborious cleaning procedure with the machine is open.
Furthermore, the machine has a simple and inexpensive construction, as it utilizes the condensed water collected in the container to wash the filter, without requiring any complex washing system.
The machine of the invention also allows quick and easy washing of the condenser located downstream from the air filter.
The discharge of a considerable amount of water in a short time allows satisfactory cleaning of the components flushed by the flow.
Those skilled in the art will obviously appreciate that a number of changes and variants may be made to the arrangements as described hereinbefore to meet incidental and specific needs, without departure from the scope of the invention, as defined in the following claims.

Claims

A laundry dryer machine comprising a drum (13) with a cavity (41) for receiving the laundry to be dried, heating means (14) for heating a drying air, a condenser (15) for removing moisture from the drying air and conveying means (16), for successively circulating the drying air through the drum (13), the condenser (15) and the heating means (14), the machine further comprising a collection container (32) for collecting the water condensed in the condenser (15) and a drying air filter (26), said collection container (32) having at least one drain (75, 175, 275) for draining the water contained in the collection container (32) towards said filter (26), characterized in that, at least in an operating state, the collection container (32) is placed above said filter (26).
A machine as claimed in claim 1, characterized in that it comprises controllable means (73, 162, 262, 282) for feeding a volume of water already collected in the collection container (32) to the drain (75, 175, 275), said controllable means (73,162,262,282) being adapted to lower the water level in the collection container (32) below a maximum level that can be reached by water in said collection container (32, 132).
A machine as claimed in claim 2, characterized in that said means for feeding a volume of water to the drain comprise a valve (73, 162) associated with the drain (75, 175), that can be opened to control water discharge.
A machine as claimed in claim 3, characterized in that said valve (162) is interposed between the drain (175) and a conduit (160) that opens into the collection container (32, 132) and is located at a level lower than the maximum water level in the collection container (32, 132).
A machine as claimed in claim 3 or 4, characterized in that the valve (73) is controlled by machine control means.
A machine as claimed in one or more of the preceding claims, characterized in that the container (32, 132) comprises an overflow conduit (72, 161), which puts the inner volume of said collection container (32,132) in communication with said drain (75, 175) to define the maximum water level in the collection container (32,132).
A machine as claimed in one or more of the preceding claims, characterized in that the condenser (15) is placed at a level below the filter (26), so that the water discharged through the drain (75) may also flow by gravity through the condenser (15).
A machine as claimed in one or more of the preceding claims, characterized in that a collection tank (30) for water just condensed is placed downstream from the condenser (15), a pump (31) being provided for feeding the water from the collection tank (30) to the collection container (32).
A machine as claimed in one or more of the preceding claims, characterized in that, at least in an operating drying state, said collection container (32) is mounted to a door (39) that is adapted to close an opening for access to the cavity (41) of the drum (13).
A machine as claimed in one or more of the preceding claims, characterized in that an outlet passageway (51) for letting drying air out of the drum (13) is placed directly below the collection container (32).
A machine as claimed in one of claims 1-10, characterized in that the means for feeding a volume of water to the drain (275) comprise a conduit that puts the inside of the collection container (232) in communication with the drain (275), said conduit being made of a first stationary part (280) connected to the drain (275) and a second movable part (281), moving relative to said first stationary part (280), that carries an opening (282) defining the maximum water level in the collection container (232).
A machine as claimed in one of claims 1-11, characterized in that said means for feeding a volume of water to the drain (275) are such that, after drainage, a volume of water of at least one third of the overall capacity of the collection container (132, 232) is left in said same collection container (132,232).
A machine as claimed in one of claims 1-12, characterized in that the volume of water that can be drained by the means for feeding a volume of water is at least one sixth of the overall volume of the collection container (132,232).
A machine as claimed in one or more of the preceding claims, characterized in that the drying air filter (26) is located in such a position as to be able to filter air that exits from the drum (13).