LAUNDRY WASHING MACHINE EQUIPPED WITH A MICROPARTICLES FILTER DEVICE AND METHOD FOR CONTROLLING SAID MACHINE

Abstract

A laundry washing machine including a washing tub containing a washing drum washed, a liquid supply system a draining system fluidly arranged downstream the washing tub and comprising a draining pump that has an inlet fluidly connected to the washing tub and an outlet fluidly connected to an outlet pipe to drain liquid outside an outer cabinet. A microparticles filter device arranged downstream the draining pump and including a housing body, an inlet a filtering chamber housed in the housing body. a first outlet for delivering filtered liquid towards the outlet pipe, and a second outlet fluidly connected to the draining system upstream the draining pump and arranged at a higher vertical level with respect to the draining pump such that a portion of the filtered liquid is cyclically circulated through the microparticles filter device during the operation of the draining pump or returned towards said draining system when the draining pump is not operating.

Description

FIELD OF THE INVENTION

The present invention concerns the field of laundry washing techniques.

Specifically, the invention relates to a laundry washing machine equipped with a microparticles filter device. The invention also relates a method for controlling the machine.

BACKGROUND ART

Nowadays the use of laundry washing machines, both “simple” laundry washing machines (i.e. laundry washing machines which can only wash, rinse and spin laundry) and laundry washing-drying machines (i.e. laundry washing machines which can also dry laundry by means of a drying airflow), is widespread.

In the present description the term “laundry washing machine” will refer to a simple laundry washing machine or a laundry washing-drying machine.

As known, in laundry washing machine laundry to be washed is received in a rotatable washing drum contained in a washing tub.

It is known that during laundry washing cycles, laundry undergoes to mechanical and/or chemical treatments inside the washing drum with the use of a washing liquor, typically water with the possible addition of washing/rinsing products such as detergent, softener, rinse conditioner, etc.

Laundry to be treated in a laundry washing machine typically comprises clothes and linens made of natural or synthetic fabrics. During washing and/or rinsing treatments, laundry loses tiny particles, called microparticles or microfibers. In particular, clothes comprising synthetic materials lose tiny plastic particles fibres, called microplastics, which are non-biodegradable.

Microparticles/microplastics end up in the wastewater drained from the laundry washing machine and eventually end up in the environment contributing to environmental pollution. For example, microplastics washed off from laundry greatly contribute to plastic that is polluting seas and oceans.

Different solutions have been proposed in known laundry washing machines by arranging a microparticles filter to capture microparticles and reduce their drainage in the wastewater.

In a first type of known systems, the microparticles filter is placed outside the machine along the draining hose that is connected to a drainage.

In different embodiments of known systems, the microparticles filter is placed along a proper hydraulic line inside the machine and is then removable therefrom for maintenance.

A first known system for microparticles filtration used in laundry washing machine is disclosed in WO2020089727A1. Here an assembly comprising a microparticles filter group is positioned along a drainage hose and a filter body houses the filter group. The assembly is made in cylindrical shape and is insertable/removable as a cartridge through an opening made on an outer washing machine wall to allow maintenance and replacement operations of the filter group. The assembly is arranged in the lower right side of the machine and the drainage hose extends vertically up to its upper end protruding outside the machine.

A drainage pump group is also positioned along the drainage hose and is connected to the filter assembly. When the drainage pump group operates, the liquid is filtered by the filter group and then expelled to the outside through the drainage hose. When the drainage pump group is not operating, for example at the end of a washing cycle, a user may intervene for maintenance by extracting the filter assembly from the washing machine wall.

A first drawback of the known system arises after the drainage pump group is stopped when residue liquid may remain inside the filter body housing. Residue liquid may favour proliferation of bacteria and yeasts, which may worsen the hygienic conditions and/or may cause bad smells.

Another drawback of the known system arises when the filter assembly is extracted from the washing machine cabinet wall. After the drainage pump group is stopped, in fact, residue liquid may remain inside the filter body. When the filter assembly is extracted from the washing machine said residue liquid may spill outside the machine and eventually falling on the floor. This makes maintenance operations uncomfortable for a user, who has to manage periodical filter cleaning and/or substitution operation acting on a heavily wet environment with the risk of getting dirty or even dispersing collected microparticles around the washing machine.

The object of the present invention is therefore to overcome the drawback posed by the known techniques.

An object of the invention to provide a laundry washing machine that makes it possible to reduce proliferation of bacteria and/or yeasts therefore improving hygienic conditions.

Another object of the present invention is therefore to provide a solution that makes periodical maintenance operations more comfortable, in particular for the washing machine user, compared to known system.

Still a further object of the present invention is to reduce the risk of getting dirty when operating on a microparticles filter device.

DISCLOSURE OF INVENTION

Applicant has found that by providing a laundry washing machine comprising a washing tub containing a washing drum suited to receive the laundry to be washed, a draining system, fluidly arranged downstream the washing tub and comprising a draining pump that has an inlet fluidly connected to the washing tub and an outlet fluidly connected to an outlet pipe to drain liquid outside the cabinet; a microparticles filter device arranged in the draining system and having an inlet for liquid to be filtered and a first outlet for delivering filtered liquid towards the outlet pipe and by providing the microparticles filter device with a second outlet which is fluidly connected to the draining system upstream the draining pump and arranged at a higher vertical level with respect to the draining pump it is possible to reach the mentioned objects.

In a first aspect thereof the present invention relates, therefore, to a laundry washing machine comprising:

• • an outer cabinet;
  • a washing tub containing a washing drum suited to receive the laundry to be washed;
  • a liquid supply system suitable to convey a liquid to said washing tub;
  • a draining system, fluidly arranged downstream said washing tub and comprising a draining pump that has an inlet fluidly connected to said washing tub and an outlet fluidly connected to an outlet pipe to drain liquid outside said outer cabinet;
  • a microparticles filter device arranged downstream said draining pump, said microparticles filter device comprising:
  • a housing body;
  • an inlet for liquid to be filtered;
  • a filtering chamber housed in said housing body, said filtering chamber comprising a microparticles filter element having a filtering surface on which microparticles accumulate while said liquid flows therethrough;
  • a first outlet for delivering filtered liquid towards said outlet pipe;
    wherein said microparticles filter device further comprises a second outlet which is fluidly connected to said draining system upstream said draining pump and arranged at a higher vertical level with respect to said draining pump such that a portion of said filtered liquid is cyclically circulated through said microparticles filter device during the operation of said draining pump or returned towards said draining system when said draining pump is not operating.

The second outlet is arranged at a higher vertical level with respect to the draining pump considering the machine placed in its standing working position. Preferably, the second outlet is provided in a liquid stagnation or sump portion of the microparticles filter housing body.

Advantageously, when the draining pump is not operating, the (residue) liquid inside the filtering chamber exits the second outlet and returns towards the draining system and the filtering chamber remains completely emptied. Removal of any residue liquid in the filtering chamber avoids proliferation of bacteria and/or yeasts thus improving hygienic conditions and preventing bad smells.

Preferably, the majority of the microparticles filter device is arranged inside the outer cabinet of the laundry washing machine.

In a preferred embodiment, the microparticles filter device is arranged in an upper position of the machine.

This position enhances the user interaction with the microparticles filter device.

Preferably, the draining system further comprises an objects filter device arranged upstream the draining pump for stopping objects having a maximum dimension higher than 5 mm contained in the liquid to be filtered when the liquid flows therethrough.

Advantageously, the objects filter device prevents undesirable objects to reach the draining pump causing a potential damage thereto.

According to a preferred embodiment of the invention, the second outlet of the microparticles filter device is fluidly connected upstream said objects filter device.

Advantageously, filtered liquid coming from the microparticles filter device mixes with unfiltered liquid coming from the washing tub and dilutes it.

In a preferred embodiment, the microparticles filter device comprises a cleaning device movably arranged in the filtering chamber for removing microparticles that accumulate on the filtering surface, the cleaning device moving microparticles removed from the filtering surface towards a storage volume of a collecting chamber arranged at a side of the filtering chamber and in communication therewith.

Preferably, the collecting chamber is configured to be removably coupled with respect to the housing body.

According to a preferred embodiment of the invention, the cleaning device comprises at least a portion extending into the storage volume of the collecting chamber thereby providing an extraction aid member to remove the cleaning device from the housing body when the collecting chamber is removed from the housing body.

Advantageously, the collecting chamber, when coupled with the housing body of the microparticles filter device, closes an opening, which is provided in said housing body, through which, or by means of which, an extraction aid member can be reached by a user to remove the cleaning device from the housing body. In one embodiment, the extraction aid member can be removed from the housing body by passing the cleaning device through said opening.

In a preferred embodiment, the collecting chamber is embodied as a cap for closing an opening provided in the housing body.

In a preferred embodiment, the portion of the cleaning device extending into the storage volume, provided in said collecting chamber to accumulate microparticles, occupies a volume portion of the storage volume ranging from 2% to 30%, or 25% or 20% or 15% or 10% or 8% or 5% of the overall storage volume. The volume portion occupied by the portion of the cleaning device extending into said storage volume is dimensioned according to the microparticles accumulation capacity that has to be assigned to the microparticles filter device, taking also into account the free space available within the outer cabinet of a laundry treating machine and the resulting size of the microparticles filter device. This has beneficial advantages on increasing the number of laundry treatments that the machine can perform without emptying the collecting chamber.

In an embodiment of the invention, the cleaning device extends into the storage volume of said collecting chamber, along an extension direction which is ranging from 15% to 100% of the storage volume extension along the same direction.

In an embodiment of the invention wherein the cleaning device extends into the storage volume of the collecting chamber along an extension direction which is lower than 100% of the storage volume extension along the same direction, the cleaning device has a cantilever end portion inside the storage volume, i.e. inside the collecting chamber.

Advantageously, when the collecting chamber is removed from the housing body the portion of the cleaning device extending into the collecting chamber may be used as an extraction aid member to remove the cleaning device. After removal of the cleaning device, the microparticles filter element is advantageously accessible for a proper cleaning process.

In a preferred embodiment, the microparticles filter element is removably arranged in the filtering chamber.

Advantageously, the microparticles filter element may be extracted out from the filtering chamber and from the housing body for a proper cleaning process or substitution, if necessary.

Further advantageously, the microparticles filter element may be extracted out from the filtering chamber and from the housing body through an opening provided in the housing body.

In one embodiment the same opening provided in the housing body allows the extraction of the cleaning device and the microparticles filter element from the housing body.

According to a preferred embodiment of the invention, the cleaning device is configured to be removably coupled to the filtering chamber.

Advantageously, the cleaning device may be easily extracted out from the filtering chamber so that the microparticles filter element and its filtering surface are advantageously accessible from outside. A user may hence advantageously reach the microparticles filter element and its filtering surface for a proper cleaning process.

In a preferred embodiment, the cleaning device comprises a rotatable element apt to remove microparticles that accumulate on the filtering surface.

Preferably, the rotatable element comprises a worm comprising a first end shaft body, a second end shaft body and a helix-shaped element connecting the end shaft bodies and winding around a main axis.

According to a preferred embodiment of the invention, the rotatable element further comprises a central shaft body extending along the main axis between the first and second end shaft bodies, wherein the helix-shaped element winds around the central shaft body.

Advantageously, the rotatable element wipes a side of the filtering surface of the microparticles filter element and moves microparticles towards the collecting chamber, acting as a worm conveyor.

In a preferred embodiment, the helix-shaped element at least partially extends into the collecting chamber.

Advantageously, microparticles moved towards the collecting chamber are pressed therein maximizing the storage of microparticles inside the collecting chamber.

Preferably, the cleaning device comprises a translatable element provided for wiping a side of the filtering surface.

According to a preferred embodiment of the invention, an actuating device is provided for moving the cleaning device.

In a preferred embodiment, the actuating device comprises an electric motor.

Preferably, the cleaning device and the collecting chamber are removably coupled one another, so that when the collecting chamber is removed from the housing body the collecting chamber is disconnected from the cleaning device.

In a further alternative preferred embodiment, the cleaning device and the collecting chamber are removably connected one another by means of a releasable locking device, so that they can be disconnected one from the other by releasing the releasable locking device after being unitarily removed from said housing body.

Preferably, the collecting chamber is screwable to the housing body.

Advantageously, the collecting chamber may be easily disconnected/connected from/to the housing body.

In a preferred embodiment, the microparticles filter element is a disposable filter element.

According to a preferred embodiment of the invention, the microparticles filter device is arranged in the draining system.

In a preferred embodiment, the outer casing of the machine further comprises an aperture so that the collecting chamber of the microparticles filter device is accessible therefrom. Preferably, the outer casing further comprises an openable door associated to the aperture.

According to a preferred embodiment of the invention, the collecting chamber is arranged to close the aperture so that the collecting chamber is directly accessible to a user.

In a further preferred embodiment of the invention, the microparticles filter device is mounted to an outer side of a wall of the outer cabinet and the inlet of the microparticles filter device is connected to the draining system by means of an outlet pipe ending outside the outer cabinet of the laundry washing machine.

Preferably, the microparticles filter device is mounted to an outer side of a wall of the outer cabinet by means of a connecting device.

According to this embodiment, advantageously, an existing laundry washing machine may be equipped with a microparticles filter device preventing microparticles leaving the laundry washing machine.

Preferably, the microparticles filter device is a filter suitable to retain particles having a minimum dimension comprised between 0.1 μm and 5 mm, preferably a minimum dimension comprised between 10 μm and 100 μm, more preferably a minimum dimension comprised between 10 μm and 75 μm.

Advantageously, the microparticles filter device is suitable to retain particles present in the waste liquid produced by mechanical and/or chemical treatments of the laundry inside the washing drum, preferably tiny plastic particles released by the laundry, also indicated as microplastics, which are non-biodegradable.

According to a preferred embodiment of the invention, the liquid supply system includes at least one recirculation system for draining liquid from a bottom region of the washing tub to a second region of the washing tub.

In a further aspect thereof, the present invention relates to a method for operating a laundry washing machine realized as described above wherein the method comprises a step wherein said draining pump is operated so that a first portion of said liquid filtered by the microparticles filter device is drained out of the laundry washing machine while a second portion of liquid filtered by the microparticles filter device is cyclically circulated between the draining pump and the microparticles filter device, and a step wherein said draining pump is not operated and liquid filtered by said the microparticles filter device and remaining therein at the end of the draining pump operation is returned towards said draining system.

Preferably, if the laundry washing machine includes at least the feature that the collecting chamber is configured to be removably coupled with respect to the housing body then, in the step wherein the draining pump is not operated, the collecting chamber is removed from the housing body of the microparticles filter device.

Preferably, if the laundry washing machine includes at least the feature that the microparticles filter device comprises a cleaning device movably arranged in said filtering chamber for removing microparticles that accumulate on the filtering surface and the feature that the cleaning device comprises at least a portion extending into the collecting chamber thereby providing an extraction aid member to remove the cleaning device from the housing body then, in the method step wherein the draining pump is not operated, the cleaning device is removed from said housing body.

Preferably, if the laundry washing machine includes at least the feature that the cleaning device and the collecting chamber are removably connected one another by means of a releasable locking device, so that they can be disconnected one from the other by releasing said releasable locking device after being unitarily removed from said housing body then, in the method step wherein the draining pump is not operated, the removal of the collecting chamber from the housing body causes the cleaning device to be removed from the housing body.

Preferably, if the laundry washing machine includes at least the feature that the microparticles filter element is removably arranged in the filtering chamber then, in the method step wherein the draining pump is not operated, the microparticles filter element is removed from the filtering chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the present invention will be highlighted in greater detail in the following detailed description of some of its preferred embodiments, provided with reference to the enclosed drawings. In the drawings, corresponding characteristics and/or components are identified by the same reference numbers. In particular:

FIG. 1 shows a frontal view of a laundry washing machine according to a first embodiment of the invention;

FIG. 2 shows a schematic view of the laundry washing machine of FIG. 1;

FIG. 3 shows a lateral view of the laundry washing machine of FIG. 1 with an external side wall removed therefrom;

FIG. 4 shows the microparticles filter device of the laundry washing machine of FIG. 3 isolated from the rest;

FIG. 5 is a longitudinal sectional view of the microparticles filter device of FIG. 4;

FIG. 6 shows the microparticles filter device of FIG. 5 in a first operating position;

FIG. 7 shows an exploded view of the microparticles filter device of FIG. 5;

FIG. 8 shows a further embodiment of an element of the microparticles filter device according to the invention;

FIG. 9 shows a schematic view of the laundry washing machine of the invention according to a further embodiment of the invention;

FIG. 10 shows a schematic view of the laundry washing machine of the invention according to another embodiment of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

As described below, the present invention has proved to be particularly advantageous when applied to laundry washing machines, i.e. appliances able to carry out at least a washing process on laundry and optionally further able to perform a drying process on laundry. In this view the present invention can be applied to laundry washing and drying machines.

With reference to FIGS. 1 to 3, a preferred embodiment of a laundry washing machine 1 according to the invention is described.

The laundry washing machine 1 preferably comprises an external casing or outer cabinet 2, a washing tub 3, a container 4, preferably a perforated washing drum 4, where the laundry to be treated can be loaded.

The washing tub 3 and the washing drum 4 both preferably have a substantially cylindrical shape.

The cabinet 2 at its front side wall 2a is provided with a loading/unloading door 8 which allows access to the washing drum 4.

The washing drum 4 is advantageously rotated by an electric motor, as known in the art, which preferably transmits the rotating motion to the shaft of the washing drum 4, advantageously by means of a belt/pulley system. In a different embodiment of the invention, the motor can be directly associated with the shaft of the washing drum 4.

The washing drum 4 is advantageously provided with holes or apertures which allow the liquid flowing therethrough. Said holes are typically and preferably homogeneously distributed on the cylindrical side wall of the washing drum 4.

The bottom region 3a of the washing tub 3 preferably comprises a seat 15, or sump, suitable for receiving a heating device 10. The heating device 10, when activated, heats the liquid collected inside the sump 15.

In further embodiments, other type of heating device may be advantageously placed in the machine 1 to heat liquid.

Preferably, the laundry washing machine 1 comprises a device 19 suited to sense (or detect) the liquid level inside the washing tub 3.

The sensor device 19 preferably comprises a pressure sensor which senses the pressure in a chamber formed in, or connected to, the washing tub 3. Such chamber can be partially filled by the liquid contained in the washing tub 3, thereby modifying the pressure in the unfilled portion of said chamber. From the pressure values sensed by the sensor device 19 it is possible to determine the liquid level of the liquid inside the washing tub 3. In another embodiment, not illustrated, laundry washing machine may preferably comprise (in addition to or as a replacement of the pressure sensor) a level sensor (for example mechanical, electro-mechanical, optical, etc.) adapted to sense (or detect) the liquid level inside the washing tub 3.

A liquid (water) supply system 5 is preferably arranged in the upper part of the laundry washing machine 1 and is suited to supply water into the washing tub 3 from an external water supply line E. The water supply system 5 preferably comprises a controlled supply valve 5a which is properly controlled, opened and closed, during a washing cycle to properly carry out all the phases thereof. The water supply system of a laundry washing machine is well known in the art, and therefore it will not be described in detail.

Liquid supply system refers, in general, to any system apt to supply water or any liquid into the tub.

The laundry washing machine 1 advantageously comprises a treating agents dispenser 14 to supply one or more treating agents into the washing tub 3 during a washing cycle. Treating agents may comprise, for example, detergents, rinse additives, fabric softeners or fabric conditioners, waterproofing agents, fabric enhancers, rinse sanitization additives, chlorine-based additives, etc.

Preferably, the treating agents dispenser 14 comprises a removable drawer 6 provided with various compartments suited to be filled with the treating agents.

In the preferred embodiment here illustrated, the water is supplied into the washing tub 3 from the water supply system 5 by making it flow through the treating agents dispenser 14 and then through a supply pipe 18. The provision of the treating agents to the washing tub 3 may be performed by automatically dosing an amount of said agents before delivering them to the washing tub 3. Such dosage is preferably performed by a dosing device having metering means for measuring a desired amount of an agent to be taken from a treating agent storage and delivered to the washing tub 3.

In an alternative embodiment of the invention, a further separate water supply pipe can be provided, which supplies exclusively clean water into the washing tub from the external water supply line.

In further preferred embodiments, not illustrated herein, a water softening device may preferably be arranged/interposed between the external water supply line and the treating agents dispenser so as to be crossed by the fresh water flowing from the external water supply line. The water softening device, as known, is structured for reducing the hardness degree of the fresh water drawn from the external water supply line and conveyed to the treating agents dispenser.

In a different embodiment, the water softening device may be arranged/interposed between the external water supply line and the washing tub, so as to be crossed by the fresh water flowing from the external water supply line and conveying it directly to the washing tub.

Laundry washing machine 1 preferably comprises a draining system 20 to drain liquid outside the cabinet 2 up to a drainage (not shown). More preferably the draining system 20 withdraws liquid from the bottom region 3a of the washing tub 3 and drains it outside the cabinet 2.

The draining system 20 preferably comprises a main pipe 22, a draining pump 24 and an outlet pipe 26 ending outside the cabinet 2.

Preferably, the draining pump 24 is a centrifugal pump provided with a rotating component, or impeller, that moves the liquid to a pump fluid outlet 24a.

The draining system 20 preferably further comprises an objects filter device 28 arranged between the main pipe 22 and the draining pump 24.

The objects filter device 28 is adapted to stop objects before they reach the draining pump 24. The objects filter device 28 has the aim of retain undesirable objects that may damage the draining pump 24, for example may damage the impeller in case a centrifugal pump design is used.

Said kind of objects, also indicated hereinafter as coarse material, may comprise, for example, buttons, coins, screws, needles, paper clips, pieces of clothes, etc.

Preferably, the objects filter device 28 is suitable to filter objects having a maximum dimension higher than 5 mm.

In a preferred embodiment, the objects filter device preferably comprises a casing having a housing wherein an objects filter element is received. The housing preferably forms a channel through which liquid to be filtered flows. Said objects filter element is preferably provided with a meandering structure, for example in the form of tabs that are arranged along the channel when the objects filter element is placed within the housing so as to create a labyrinthic path through which the liquid flows while objects are stopped by the tabs.

For cleaning purposes, the objects filter device 28 can preferably be removed from the housing and from the cabinet 2 through an openable gate 13 placed advantageously on the front side wall 2a of the cabinet 2, as illustrated in FIG. 1.

The objects filter device 28 and respective gate 13 are arranged in the lower part of the laundry washing machine 1, more preferably in the lower right side of the laundry washing machine 1.

The draining pump 24 and the objects filter device 28 are preferably embodied as a group assembly, for example by directly connecting the draining pump 24 to the casing defining the housing of the objects filter device 28.

The main pipe 22 preferably connects the bottom region 3a of the washing tub 3 to the objects filter device 28.

In a further embodiment, not illustrated, the casing of the objects filter device may be provided directly in the washing tub, preferably obtained in a single piece construction with the latter. In this case, the objects filter device is fluidly connected to the outlet of the washing tub, in such a way that liquid drained from the washing tub enters the objects filter device.

Activation of the draining pump 24 drains the liquid, i.e. water or water mixed with washing and/or rinsing products, from the washing tub 3 to the outside.

Laundry washing machine 1 advantageously comprises a control unit 11 which is in signal and/or electrical communication to the various operational parts of the laundry washing machine 1 such as drum motor, sensors, etc., in order to ensure its operation for carrying out a laundry treating program. The control unit 11 is advantageously connected also to an interface unit 11a which is accessible to the user and by means of which the user selects and sets the washing parameters from time to time, in particular a desired laundry washing or treating program.

According to an aspect of the invention, the laundry washing machine 1 comprises a microparticles filter device 30. According to the preferred embodiment shown in FIGS. 1 to 7, the microparticles filter device 30 is preferably arranged in the draining system 20. Preferably the microparticles filter device 30 is arranged along the outlet pipe 26 of the draining system 20, more preferably in a portion of said outlet pipe 26 contained within the volume defined by the cabinet 2.

The microparticles filter device 30 is arranged downstream the draining pump 24, in particular arranged downstream the fluid outlet 24a of the draining pump 24, that is the microparticles filter device 30 receives liquid pumped by the draining pump 24.

Before the liquid reaches a drainage outside the machine 1, liquid is therefore subjected to a filtration process preventing microparticles leaving the laundry washing machine 1.

The microparticles filter device 30 is configured to retain particles having a minimum dimension comprised between 0.1 μm and 5 mm, preferably a minimum dimension comprised between 10 μm and 100 μm, more preferably a minimum dimension comprised between 10 μm and 75 μm.

Particles of this type are typically present in the waste liquid produced by mechanical and/or chemical treatments of the laundry inside the washing drum 4 as tiny particles are released by the laundry. In particular, laundry comprising synthetic materials loses tiny plastic particles fibres, also indicated as microplastics, which are non-biodegradable.

The microparticles filter device 30, therefore, advantageously acts as a microplastics filter device 30.

The microparticles filter device 30 is preferably arranged downstream the objects filter device 28 or, in other words, the objects filter device 28 is preferably arranged upstream the microparticles filter device 30 to advantageously prevent coarse material to reach the microparticles filter device 30 causing a potential damage thereto.

The microparticles filter device 30 is better described in detail with reference to FIGS. 4 to 7.

The microparticles filter device 30 preferably shows an elongated shape that extends along a main axis X.

The microparticles filter device 30 comprises a housing body 32, preferably made of a plastic, i.e. polymeric, material.

According to the preferred embodiment illustrated in the FIGS. 1-7, the microparticles filter device 30 is preferably arranged in the upper part of the laundry washing machine 1, more preferably in the upper right side of the laundry washing machine 1. Positioning of the microparticles filter device 30 in the upper position enhances the user interaction with the same microparticles filter device 30.

The microparticles filter device 30 is preferably vertically aligned to the draining pump 24 to keep the pipe length connecting the draining pump 24 with the microparticles filter device 30 as short as possible to reduce the pump 24 strength.

The microparticles filter device 30 comprises an inlet 34 for liquid to be filtered, a filtering chamber 36 and a first outlet 38 for filtered liquid.

The inlet 34 of the microparticles filter device 30 is connected to a first portion 26a of the outlet pipe 26 and the first outlet 38 of the microparticles filter device 30 is connected to a second portion 26b of the outlet pipe 26 which preferably protrudes out of the cabinet 2, preferably from a rear side wall of the cabinet 2.

The second portion 26b of the outlet pipe 26 preferably comprises an end connector on an outer surface, preferably the real wall, of the cabinet 2 to hydraulically connect the laundry washing machine 1 to a drainage outside the machine 1.

The first portion 26a of the outlet pipe 26 fluidically connects the draining pump 24 and the microparticles filter device 30.

The filtering chamber 36, better visible in FIG. 7, receives therein a microparticles filter element 40 having a filtering surface 42 at which microparticles accumulate while the liquid flows therethrough.

An amount of the volume encased by the housing body 32 defines the filtering chamber 36.

The filtering chamber 36 is thus housed in the housing body 32.

The filtering chamber 36 is preferably cylindrically shaped and the microparticles filter element 40 preferably has a cylindrical tubular shape. The filtering chamber 36 and the microparticles filter element 40 preferably extends along said main axis X. The filtering surface 42 preferably comprises a plurality of meshes 42a, more preferably rectangular meshes 42a (as visible in FIG. 7).

Meshes 42a are preferably realized with a woven wire. In a preferred embodiment the wire is made of polyethylene. Said plurality of meshes 42a can be provided by one or more layers of woven wire covering a plurality of openings formed in a body portion of the microparticles filter element 40.

Preferably, the mesh is chosen to have a mesh size configured to retain particles having a minimum dimension comprised between 0.1 μm and 5 mm, preferably a minimum dimension comprised between 10 μm and 100 μm, more preferably a minimum dimension comprised between 10 μm and 75 μm, as said above.

The microparticles filter element 40 preferably defines an unfiltered volume 43 apt to receive the liquid before its filtration and coming from the inlet 34. According to the preferred embodiment here illustrated, the unfiltered volume 43 corresponds to the inner cylindrical volume of the microparticles filter element 40. In a normal operating condition of the microparticles filter device 30, the liquid is supplied into the unfiltered volume 43 from the inlet 34 and then undergoes to filtration by passing through the microparticles filter element 40, in particular by passing through meshes 42a. The filtered liquid thus reaches an elongated annular chamber 44 that is radially outer the microparticles filter element 40 and that forms part of the filtering chamber 36. The elongated annular chamber 44 hydraulically communicates with the first outlet 38 of the microparticles filter device 30.

While the liquid flows through the microparticles filter element 40, microparticles progressively accumulate on the filtering surface 42.

The extension of the filtering chamber 36 along the main axis X substantially corresponds to the filtering area defined by the microparticles filter element 40 and, more preferably, defined by said meshes 42a.

Nevertheless, the filtering chamber 36 may comprise portions that extends outside said filtering area and that are preferably used to assemble the microparticles filter element, for example for receiving sealing elements as described later, or for the connection of the microparticles filter element to other parts of the microparticles filter device.

According to an aspect of the invention, the microparticles filter device 30 further comprises a second outlet 102 which is fluidly connected to the draining system 20 upstream the draining pump 24. Preferably, the second outlet 102 is provided in a liquid stagnation or sump portion 33 of the microparticles filter housing body 32. The liquid stagnation or sump portion 33 is preferably embodied as a funnel-shaped part of the main body 32.

Further, preferably, the second outlet 102 is fluidly connected to the draining system 20 through a discharging duct 104. The discharging duct 104 terminates upstream the draining pump 24. According to the preferred embodiment illustrated in the FIGS. 1-7, the discharging duct 104 is preferably directly connected to the objects filter device 28.

According to another aspect of the invention, the microparticles filter device 30 is arranged so that the second outlet 102 is at a higher vertical level with respect to the draining pump 24.

The second outlet 102 is arranged at a higher vertical level with respect to the draining pump 24 considering the machine 1 placed in its standing working position.

In the normal operating condition of the laundry washing machine 1, as described above, when the draining pump 24 is operated, a first portion of the liquid is supplied into the unfiltered area 43 from the inlet 34 and then undergoes to filtration by passing through the microparticles filter element 40. The first portion of filtered liquid reaches thus the annular chamber 44 external to the microparticles filter element 40 and from there it is drained outside the cabinet 2 through the first outlet 38 and the second portion 26b of the outlet pipe 26.

In the same operating condition, a second portion of the filtered liquid from the annular chamber 44 exits the second outlet 102, flows through the discharging duct 104 and discharged upstream the draining pump 24. Said second portion of filtered liquid is thus subjected again to the pumping action of the draining pump 24 that, together with the liquid coming from the main pipe 22, conveys the liquid again towards the microparticles filter device 30 through the first portion 26a of the outlet pipe 26.

As the draining pump 24 is operated (normal operating condition), therefore, part of the filtered liquid (the first portion of filtered liquid) is drained outside the cabinet 2 through the first outlet 38 and a second portion of the filtered liquid is cyclically circulated through the microparticles filter device 30 flowing through the second outlet 102, the discharging duct 104, the draining pump 24 and the first portion 26a of the outlet pipe 26.

Advantageously, filtered liquid which is cyclically circulated through the microparticles filter device 30 undergoes to a more efficient filtering process with multiple filtrations before releasing the liquid outside the laundry washing machine 1.

Furthermore, advantageously, the second portion of filtered liquid coming from the discharging duct 104 mixes with unfiltered liquid coming from the sump 15 through the main pipe 22 and dilutes it. Dilution of the liquid, that is then pumped by the draining pump 24 to the microparticles filter device 30, enhances the filtration by the microparticles filter device 30 since the filtering surface 42 of the microparticles filter element 40 gets clogged more uniformly thus maintaining the efficiency longer over time.

When the draining pump 24 is not operating, or stopping operating condition, the liquid is not conveyed to the microparticles filter device 30 and hence not drained outside the cabinet 2. In this condition, residue liquid may remain inside the filtering chamber 36.

According to an advantageous aspect of the invention, when the draining pump 24 is not operating, the liquid, or residue liquid, collecting in the stagnation or sump portion 33 of the microparticles filter housing body 32, inside the filtering chamber 36, returns towards the draining system 20 through the second outlet 102 and the discharging duct 104 by means of gravity force.

Preferably, the (residue) liquid exits the second outlet 102 of the filtering chamber 36 and falls through the discharging duct 104 towards the draining system 20, more preferably towards the objects filter device 28 where the discharging duct 104 terminates. The filtering chamber 36 thus remains completely emptied.

Removal of any residue liquid in the filtering chamber 36 avoids proliferation of bacteria and/or yeasts thus improving hygienic conditions and preventing bad smells.

According to another aspect of the invention, the microparticles filter device 30 is equipped with a cleaning device 50 which is configured to remove microparticles that accumulate on the first side of the filtering surface 42 of the filtering element 40 that the liquid encounters when passing through said filtering surface 42.

The cleaning device 50 is preferably arranged inside the microparticles filter element 40 for moving microparticles it removes from the filtering surface 42 towards a storage volume 61 of a collecting chamber 60. The collecting chamber 60 is arranged at a side, in particular an end side, of the filtering chamber 36 and in communication therewith.

According to the preferred embodiment described herein, the movable cleaning device 50 comprises a rotatable element 51 wiping a side of the filtering surface 42, preferably wiping the first side of the filtering surface 42 that the liquid encounters and where microparticles accumulates. More preferably, the rotatable element 51 may be embodied as a worm having a first end shaft body 52, a second end shaft body 54 and a helix-shaped element 56 connecting the end shaft bodies 52, 54 and winding around a main axis X.

This main axis X corresponds to the direction through which the rotatable element 51 extends. In the preferred embodiment described herein, this main axis X preferably coincides with the main axis X of the microparticles filter device 30.

The helix-shaped element 56 is preferably a circular helix-shaped element 56. The central part of the rotatable element 51, embodied as a worm, between the end shaft bodies 52, 54 and enclosed by the helix-shaped element 56 is therefore void and therefore the rotatable element 51 is embodied as a hollow worm.

In the embodiment described above, the rotatable element 51 is rotated around the main axis X, the helix-shaped element 56 wipes a side of the filtering surface 42 of the microparticles filter element 40 thereby removing microparticles accumulated thereon, and, at the same time, it is able to move microparticles towards the storage volume 61 of the collecting chamber 60, acting as a worm conveyor.

Microparticles are therefore collected into the storage volume 61 of the collecting chamber 60 as the rotatable element 51 rotates. Microparticles removed from the filtering surface 42 are conveyed towards the storage volume 61 of the collecting chamber 60 and towards an opening 37 provided in the housing body 32, such that microparticles can be removed from the microparticles filter device 30 by removing the collecting chamber 60 therefrom.

Preferably, the helix-shaped element 56 of the rotatable element 51 has its terminal part 56a that at least partially extends into the storage volume 61 of the collecting chamber 60.

Advantageously, microparticles moved towards the collecting chamber 60 are pressed in the storage volume 61 by the action of the terminal part 56a of the rotatable element 51. Microparticles are preferably squeezed inside the storage volume 61 with removal of the surplus of liquid contained therein that flow back to the filtering chamber 36. This maximizes the storage of microparticles inside the storage volume 61.

Rotation of the rotatable element 51 is preferably obtained through an actuating device 70.

The actuating device 70 is preferably arranged at said first end shaft body 52 of the rotatable element 51 and preferably comprises an electric motor 72 having a rotatable shaft 74 cooperating with the first end shaft body 52 of the rotatable element 51.

An interconnection device 76 is preferably arranged between the first end shaft body 52 of the rotatable element 51 and the rotatable shaft 74 of the electric motor 72. The interconnection device 76 allows transmission of rotation of the rotatable shaft 74 to the rotatable element 51 and also allows disconnection of the rotatable element 51 from the rotatable shaft 74 so that the rotatable element 51 may be removed from the filtering chamber 36, as better described later.

Preferably, the interconnection device 76 comprises a joint element 78 rotatably mounted on the housing body 32 of the microparticles filter device 30 through a ball round bearing 80. The joint element 78 comprises a first end 82 connected to the shaft 74 of the motor 72 and a second end with a seat 84 receiving the first end shaft body 52 of the rotatable element 51. The seat 84 and the first end shaft body 52 of the rotatable element 51 are complementarily shaped, for example a cylindrical shape with a flat portion is used, so that they can rotate together when the rotatable element 51 works/rotates and they can be disconnected when the rotatable element 51 stops, preferably by extracting the rotatable element 51 from the seat 84 when the rotatable element 51 is pulled along the main axis X direction.

According to an aspect of the invention, the collecting chamber 60 is configured to be removably coupled with respect to the housing body 32. The collecting chamber 60 works as a cap for the opening 37, closing the latter when it is coupled to the housing body 32.

According to a preferred embodiment illustrated in FIGS. 4-7, the collecting chamber 60 is preferably screwable to the housing body 32. A male thread 62 of the collecting chamber 60 preferably engages with a female thread 64 on the housing body 32 of the microparticles filter device 30.

Preferably, the collecting chamber 60 is screwable in a first direction to the housing body 32, preferably the clockwise direction, and the rotatable element 51 is also operated/rotated in the same first direction. Advantageously, when the rotatable element 51 is operated/rotated the risk of unscrewing the collecting chamber 60 from the housing body 32 is prevented.

In further preferred embodiments, the collecting chamber may be configured to be removably coupled to the housing body 32 by a pushing or snap-in action.

According to a further aspect of the invention, the cleaning device 50 comprises a portion 90 extending into the storage volume 61 of the collecting chamber 60 thereby providing an extraction aid member 90 to remove the cleaning device 50 from the housing body 32 when the collecting chamber 60 is removed from the housing body 32, as better described later.

According to the preferred embodiment illustrated in FIGS. 4-7, the portion 90 of the cleaning device 50 extending into the storage volume 61 of the collecting chamber 60 is preferably embodied as a portion 90 that protrudes from the filtering chamber 36 and extends into the storage volume 61 of the collecting chamber 60. In this embodiment, the cleaning device 50 extends into the storage volume 61 of the collecting chamber 60 along the axis X for the entire storage volume 61 extension along the same axis X. The volume occupied by the cleaning device portion 90 extending inside the storage volume 61 is about 5% of the storage volume where microparticles are accumulated. In different embodiments, not shown in the drawings, the cleaning device 50 may extend into the storage volume 61 along a direction, for example the axis X in the FIGS. 4-7, for only a part of the storage volume extension along the same direction. The cleaning device may thus have a cantilever end portion.

Preferably, the portion 90 comprises an elongated pin at the second end shaft body 54 of the rotatable element 51. The elongated pin 90 is preferably integrally realized with the rotatable element 51.

The elongated pin 90 and the collecting chamber 60 are preferably removably coupled one another. The elongated pin 90 is preferably received in a supporting seat 63 realized in the storage volume 61 of the collecting chamber 60.

When the rotatable element 51 rotates, the elongated pin 90 rotates within the supporting seat 63. The supporting seat 63 preferably acts as a centering means while the rotatable element 51 works/rotates.

The supporting seat 63 and the elongated pin 90 are shaped, for example both cylindrically shaped, so that the elongated pin 90 may rotate with respect to the supporting seat 63 when the rotatable element 51 rotates while the collecting chamber 60 may be disengaged from the elongated pin 90 when the collecting chamber 60 is removed (unscrewed) from the housing body 32.

The cleaning device 50 and the collecting chamber 60 are therefore preferably removably coupled one another so that the collecting chamber 60 can be disconnected from the cleaning device 50 when the collecting chamber 60 is removed from the housing body 32.

When the collecting chamber 60 is removed (unscrewed) from the housing body 32, as illustrated in FIG. 6, the elongated pin 90 provides an extraction aid member 90 to remove the rotatable element 51 from the housing body 32. The rotatable element 51 is hence also advantageously removable from the filtering chamber 36. In particular, the rotatable element 51 can be removed from the filtering chamber 36 by extracting the rotatable element 51 through the opening 37 of the housing body 32.

The elongated pin 90, in fact, can be usefully grasped by a user and pulled along the main axis X so that the rotatable element 51 disconnects from the joint element 78 and can be fully extracted out of the housing body 32.

Operating position as illustrated in FIG. 6 preferably refers to a maintenance phase of the laundry washing machine 1 when the collecting chamber 60 needs to be removed and then cleaned from microparticles stored in the storage volume 61.

As said above, from this operating position the rotatable element 51 may be fully extracted out of the housing body 32 by means of the extraction aid member 90 constituted by the elongated pin 90.

After the rotatable element 51 is fully extracted out of the housing body 32, the microparticles filter element 40 and its filtering surface 42 are advantageously accessible from outside. A user may reach the microparticles filter element 40 and its filtering surface 42 for a proper cleaning process that might be due after a relatively long operation time of the rotatable element 51 wiping a side of the filtering surface 42.

More preferably, the microparticles filter element 40 is removably arranged in the filtering chamber 36. Advantageously, after removal of the collecting chamber 60 the user may also extract the microparticles filter element 40 from the filtering chamber 36 and hence facilitating the cleaning process and/or substitution of the same in case the microparticles filter element 40 is worn out or damaged, as illustrated for example in the operating position of FIG. 7. In particular, the microparticles filter element 40 can be extracted from the filtering chamber 36 through the opening 37 of the housing body 32.

According to a preferred embodiment illustrated in the FIGS. 4-7, the microparticles filter element 40 is preferably removably received in the housing body 32 of the microparticles filter device 30 and may be preferably inserted and extracted along the main axis X, in particular through the opening 37 of the housing body 32. Therefore, the microparticles filter element 40 may be embodied as a disposable filter element that can be substituted, whenever it is necessary.

Between the microparticles filter element 40 and the housing body 32, sealing elements 46a, 46b, for example plastic, i.e. polymeric, O-rings, are preferably arranged to guarantee watertightness of the filtering chamber 36 during the filtering process.

The microparticles filter element 40 preferably extends towards the frontal part of the housing body 32 of the microparticles filter device 30 and preferably receives a portion of the collecting chamber 60 therein.

This facilitates extraction of the microparticles filter element 40 which may be grasped by the user after removal of the collecting chamber 60.

Preferably, a sealing element 47, for example plastic, i.e. polymeric, O-rings, is preferably arranged between the microparticles filter element 40 and the collecting chamber 60 to guarantee watertightness of the filtering chamber 36 during the filtering process.

As said above, the collecting chamber 60 is configured to be removably coupled with respect to the housing body 32 and in the preferred embodiment illustrated in FIGS. 4-7 the collecting chamber 60 is directly screwable to the housing body 32 through male and female threads 62, 64. In further preferred embodiments, not illustrated, the collecting chamber may be removably coupled with respect to the housing body not directly coupling the collecting chamber to the housing body. For example, the collecting chamber may be removably coupled, e.g. screwable, to the frontal part of the microparticles filter element instead of to the housing body.

In a preferred embodiment illustrated herein, the cabinet 2 comprises an aperture 7, as shown in FIG. 1, so that the collecting chamber 60 of the microparticles filter device 30 is accessible to a user, from outside the cabinet 2.

The aperture 7 is preferably realized in the upper right side of the front side wall 2a of the laundry washing machine 1 and aligned with the microparticles filter device 30.

The collecting chamber 60 is preferably arranged to close the aperture 7 of the cabinet 2 so that said collecting chamber 60 is directly accessible to the user from a part of the cabinet remaining exposed to a user interaction.

More preferably, the microparticles filter device 30 is arranged with respect to said aperture 7 of the cabinet 2 so that the exposed surface 65 of the collecting chamber 60 fits preferably flush with the front side wall 2a of the cabinet 2 of the laundry washing machine 1.

The majority of the microparticles filter device 30 is thus preferably arranged inside the cabinet 2. Parts of the collecting chamber 60 accessible to the user, for example said exposed surface 65 flushing with the front side wall 2a of the cabinet 2, may not be arranged inside the cabinet 2.

In a further preferred embodiment (not shown), the cabinet may comprise an openable door associated to the aperture 7 to give access thereto, and so that the microparticles filter device is preferably completely placed inside the cabinet.

As described above, when the draining pump 24 is not operating, the liquid, or residue liquid, collecting in the stagnation or sump portion 33 of the microparticles filter housing body 32, inside the filtering chamber 36 returns towards the draining system 20 through the second outlet 102 by effect of the gravity force.

Preferably, the (residue) liquid exits the second outlet 102 of the filtering chamber 36 and falls through the discharging duct 104 towards the draining system 20, more preferably towards the objects filter device 28 where the discharging duct 104 terminates. The filtering chamber 36 thus remains completely emptied and gets dry when the laundry washing machine 1 is not in use.

Removal of any residue liquid in the filtering chamber 36 avoids that liquid may spill outside the machine, and eventually falling on the floor, when the collecting chamber 60 is removed, preferably unscrewed, from the housing body 32 and/or when the rotatable element 51 is extracted from the filtering chamber 36 and/or when the microparticles filter element 40 is extracted from the filtering chamber 36.

FIG. 8 shows an alternative preferred embodiment of the rotatable element 251 of the invention, forming part of the cleaning device 250, which differs from the preferred embodiment previously described in that the rotatable element 251 is not a hollow worm.

The rotatable element 251 comprises a central shaft body 252 extending along the main axis X between the end shaft bodies 52, 54 and a helix-shaped element 256 that winds around the central shaft body 252, preferably integrally made with the central shaft body 252. The helix-shaped element 256 is preferably a circular helix-shaped element 256. According to this embodiment, the helix-shaped element 256 substantially defines a helicoid.

According to a further preferred embodiment, not illustrated, the cleaning device and the collecting chamber are removably connected one another by means of a releasable locking device, so that they can be disconnected one from the other by releasing said releasable locking device after being unitarily removed from the housing body.

When the collecting chamber is removed (for example unscrewed) from the housing body, the collecting chamber remains engaged with the cleaning device. Once the collecting chamber has been removed (for example unscrewed) from the housing body, the collecting chamber may be removed from the cleaning device through the releasable locking device. The collecting chamber can hence be cleaned from microparticles stored in the storage area.

FIG. 9 shows a schematic view of a further preferred embodiment of a laundry washing machine 300 according to the invention. In the drawing, corresponding characteristics and/or components of the embodiment described in FIG. 2 are identified by the same reference numbers.

This preferred embodiment of the invention differs from the preferred embodiment previously described with reference to FIG. 2 in that the laundry washing machine 300 preferably comprises a first recirculation system 330 which is adapted to drain liquid from a bottom region 3a, placed at a bottom part of the washing tub 3, and to re-admit such a liquid back again into said bottom region 3a of the washing tub 3 and a second recirculation system 340 which is adapted to drain liquid from said bottom region 3a of the washing tub 3 and to re-admit such a liquid into a second region 3b of the washing tub 3, placed at a higher level relative to the bottom region 3a.

The liquid taken from the washing tub 3 is preferably re-admitted to the bottom region 3a of the washing tub 3 for mixing and/or dissolving laundry treating products, in particular detergent in powder or liquid form. Mixing and/or dissolving of a laundry treating product is preferably carried out during a washing cycle when one of the products is supplied into the washing tub 3 from the treating agents dispenser 14.

Preferably, the second region 3b of the washing tub 3 substantially corresponds to an upper region 3b of the washing tub 3. The liquid is preferably re-admitted to the upper region 3b of the washing tub 3 to improve wetting of the laundry inside the washing drum 4. This action is preferably carried out at the beginning of a washing cycle when the laundry needs to be completely soaked. Furthermore, this action is preferably carried out during rinsing phases at the beginning of the washing cycle or during rinsing phases in successive steps of the washing cycle. Furthermore, this action can be also carried out during a main wash phase so as to efficiently reach laundry that rest in an upper region of the drum.

The first recirculation system 330 preferably comprises a first recirculation pump 332 connected downstream the objects filter device 28 and a first recirculation line 334 for conveying liquid to the bottom region 3a of the washing tub 3.

The second recirculation system 340 preferably comprises a second recirculation pump 342 connected downstream the objects filter device 28 and a second recirculation line 344 for conveying liquid to the second region 3b of the washing tub 3.

In the preferred embodiments described above, the cleaning device preferably comprises a rotatable element, in particular a worm, provided with a portion that acts as an extraction aid member.

In further preferred embodiments, the cleaning device may preferably comprise a translatable element wiping a side of the filtering surface of the microparticles filter member.

For example, the translatable element may comprise a piston with a reciprocating rectilinear motion along the main axis direction and having surfaces that wipes the filtering surface of the microparticles filter element. A motor or a pneumatic system may be preferably provided for translating the translatable element.

Furthermore, the translatable element is provided with a portion that acts as an extraction aid member, for example an elongated portion (a pin) protruding from the head of said piston.

In the preferred embodiments described above, the microparticles filter device is preferably arranged within the cabinet of the laundry washing machine.

In further preferred embodiments, the microparticles filter device may be mounted to an outer side of a cabinet wall and may be fluidly connected to the laundry washing machine draining system. In this way, a user can easily handle the microparticles filter device when it is needed to remove microparticles accumulated therein. In addition, by providing a microparticles filter device mounted to a side of a cabinet wall, i.e. outside of the inner volume defined by the laundry washing machine cabinet walls, it is possible to enlarge the microparticles storage capacity of the filter device, so as to prolong the operation of the filter device before a microparticles removal intervention is required.

FIG. 10 exemplary shows a solution of this type. In the drawing, corresponding characteristics and/or components of the first embodiment described above, in particular with reference to FIG. 2, are identified by the same reference numbers.

According to this embodiment, a microparticles filter device 430 is embodied as a unit provided to the laundry washing machine 400 by being mounted to an outer side of a wall of the outer cabinet 2. The microparticles filter device 430 is preferably mounted to the outer cabinet 2 of the laundry washing machine 400 through a connecting device 450, for example an L-shaped bracket or a hooking device. The microparticles filter device 430 preferably, though not necessarily, comprises an external housing 452 and the latest is preferably connectable/connected to the outer cabinet 2 of the laundry washing machine 400 through said connecting device 450. In another embodiment, the housing body 32 of the microparticles filter device 430 can be provided with connecting members, such as eyelets, allowing the housing body 32 to be mounted to the outer cabinet 2 of the laundry washing machine 400.

The microparticles filter device 430 may be realized according to preferred embodiments as described above.

According to this embodiment, the inlet 34 of the microparticles filter device 430 is preferably connected to the second portion 26b of the outlet pipe 26 protruding out of the cabinet 2, preferably through a proper hydraulic connector 456.

The outlet 38 of the microparticles filter device 330 is preferably provided for being hydraulically connected to a drainage outside the machine 400, preferably through an outlet pipe 454.

The second outlet 102 of the microparticles filter device 430 is preferably provided for being fluidly connected to the draining system 20 upstream the draining pump 24. The second outlet 102 is fluidly connected to the draining system 20 through the discharging duct 104.

The second outlet 102 is preferably connected to and end of the discharging duct 104, preferably through a proper hydraulic connector 458, which is made available on a cabinet wall.

Before the liquid reaches the drainage outside the machine 400, liquid is therefore subjected to a filtration process by means of the microparticles filter device 430, preventing microparticles leaving the laundry washing machine 400. In a preferred embodiment, the external housing 452 preferably comprises an aperture (not shown) so that the collecting chamber of the microparticles filter device 430 is accessible to a user, from outside the external housing 452. The collecting chamber is preferably arranged to close the aperture of the external housing 452 so that said collecting chamber is directly accessible to the user from a part of the external housing 452 remaining exposed to a user interaction.

More preferably, the microparticles filter device 430 is arranged with respect to said aperture of the external housing 452 so that the exposed surface 65 of the collecting chamber 60 fits preferably flush with a side wall of the external housing 452.

The majority of the microparticles filter device 430 is thus preferably arranged inside the external housing 452. In a further preferred embodiment, the external housing 452 may comprise an openable door associated to the aperture to give access thereto, and so that the microparticles filter device is preferably completely placed inside the external housing 452.

According to this embodiment, advantageously, an existing laundry washing machine may be equipped with a microparticles filter device according to the invention preventing microparticles leaving the laundry washing machine.

It has thus been shown that the present invention allows all the set objects to be achieved. In particular, it makes it possible to provide a laundry washing machine that reduces proliferation of bacteria and/or yeasts and improves hygienic conditions compared to known laundry washing machines.

While the present invention has been described with reference to the particular embodiments shown in the figures, it should be noted that the present invention not limited to the specific embodiments illustrated and described herein; on the contrary, further variants of the embodiments described herein fall within the scope of the present invention, which is defined in the appended claims.

Claims

1. A laundry washing machine comprising:

an outer cabinet;

a washing tub containing a washing drum suited to receive the laundry to be washed;

a liquid supply system suitable to convey a liquid to the washing tub;

a draining system fluidly arranged downstream the washing tub and comprising a draining pump that has an inlet fluidly connected to the washing tub and an outlet fluidly connected to an outlet pipe to drain liquid outside the outer cabinet; and

a microparticles filter device arranged downstream the draining pump, the microparticles filter device comprising:

a housing body;

an inlet for liquid to be filtered;

a filtering chamber housed in the housing body, the filtering chamber comprising a microparticles filter element having a filtering surface on which microparticles accumulate while the liquid flows therethrough; and

a first outlet for delivering filtered liquid towards the outlet pipe;

wherein the microparticles filter device further comprises a second outlet that is fluidly connected to the draining system upstream the draining pump and arranged at a higher vertical level with respect to the draining pump such that a portion of the filtered liquid is cyclically circulated through the microparticles filter device during the operation of the draining pump or returned towards the draining system when the draining pump is not operating.

2. The laundry washing machine according to claim 1, wherein the microparticles filter device is arranged in an upper position of the machine.

3. The laundry washing machine according to claim 1, wherein the draining system further comprises an objects filter device arranged upstream the draining pump for stopping objects having a maximum dimension higher than 5 mm contained in the liquid to be filtered when the liquid flows therethrough.

4. The laundry washing machine according to claim 3, wherein the second outlet of the microparticles filter device is fluidly connected upstream the objects filter device.

5. The laundry washing machine according to claim 1, wherein the microparticles filter device comprises a cleaning device movably arranged in the filtering chamber for removing microparticles that accumulate on the filtering surface, the cleaning device moving microparticles removed from the filtering surface towards a storage volume of a collecting chamber arranged at a side of the filtering chamber and in communication therewith.

6. The laundry washing machine according to claim 5, wherein the collecting chamber is configured to be removably coupled with respect to the housing body.

7. The laundry washing machine according to claim 5, wherein the cleaning device comprises at least a portion extending into the storage volume of the collecting chamber thereby providing an extraction aid member to remove the cleaning device from the housing body when the collecting chamber is removed from the housing body.

8. (canceled)

9. The laundry washing machine according to claim 5, wherein the cleaning device is configured to be removably coupled to the filtering chamber.

10. The laundry washing machine according to claim 5, wherein the cleaning device comprises a rotatable element configured to remove microparticles that accumulate on the filtering surface.

11-13. (canceled)

14. The laundry washing machine according to claim 5, wherein the cleaning device comprises a translatable element provided for wiping a side of the filtering surface.

15. The laundry washing machine according to claim 5, further comprising an actuating device for moving the cleaning device.

16. (canceled)

17. The laundry washing machine according to claim 5, wherein the cleaning device and the collecting chamber are removably coupled to one another, so that when the collecting chamber is removed from the housing body the collecting chamber is disconnected from the cleaning device.

18. The laundry washing machine according to claim 5, wherein the cleaning device and the collecting chamber are removably connected to one another by means of a releasable locking device, so that they can be disconnected one from the other by releasing the releasable locking device after being unitarily removed from the housing body.

19. The laundry washing machine according to claim 5, wherein the collecting chamber is screwable to the housing body.

20-26. (canceled)

27. The laundry washing machine according to claim 5, wherein the microparticles filter device is a filter suitable to retain particles having a minimum dimension ranging between 0.1 μm and 5 mm.

28. The laundry washing machine according to claim 5, wherein the liquid supply system includes at least one recirculation system for draining liquid from a bottom region of the washing tub to a second region of the washing tub.

29. A method for operating the laundry washing machine claim 1, wherein the draining pump is operated so that a first portion of the liquid filtered by the microparticles filter device is drained out of the laundry washing machine while a second portion of liquid filtered by the microparticles filter device is cyclically circulated between the draining pump and the microparticles filter device, and a step-wherein when the draining pump is not operated, liquid filtered by the microparticles filter device and remaining therein at the end of the draining pump operation is returned towards the draining system.

30. The method according to claim 29, wherein when the draining pump is not operated, the collecting chamber is removed from the housing body of the microparticles filter device.

31. The method according to claim 30, washing machine the step wherein when the draining pump is not operated, the cleaning device is removed from the housing body.

32. The method according to claim 31, wherein when the draining pump is not operated, the removal of the collecting chamber from the housing body causes the cleaning device to be removed from the housing body.

33. (canceled)