WO2014089651A1

WO2014089651A1 - A device for unidirectionally retaining solids intended for fluids, a flow line system for laundry machines, and a method in a flow line system of a laundry machine

Info

Publication number: WO2014089651A1
Application number: PCT/BR2013/000530
Authority: WO
Inventors: Felipe SCHEER; Cirilo CAVALLI; Rodrigo BERNDSEN
Original assignee: Electrolux Do Brasil S.A.
Priority date: 2012-12-12
Filing date: 2013-12-03
Publication date: 2014-06-19
Also published as: BR102012031706A2

Abstract

The present invention is related to the filtration of water, and more particularly to the filtration of water through filters that retain solid particles, such as lint. In this context, the object of the present invention is to provide a device capable of allowing the passage of liquid and solids in one direction while allowing only liquid to return in the opposite direction, and retaining the solids. One further object of the present invention is to provide a method and a fluid lines system in a laundry machine capable of avoiding waste of water in automatic filtration of solids in a recirculation washing process and simultaneously operating with fewer components. In order to fulfill the objects described above, the present invention provides a device (100) for unidirectional retention of solids in fluids, comprising at least one filter element (110) that (i) allows the passage of fluid and solids in a first direction, (ii) allows the return of liquid in a second direction, opposite the first direction and (iii) prevents the return of solids in the second direction. The present invention further provides a fluid lines system for laundry machines comprising the device mentioned above and a filtration method for that system.

Description

"A DEVICE FOR UNIDIRECTIONALLY RETAINING SOLIDS INTENDED FOR FLUIDS, A FLOW LINE SYSTEM FOR LAUNDRY MACHINES, AND A METHOD IN A FLOW LINE SYSTEM OF A LAUNDRY MACHINE"

TECHNICAL FIELD

The present invention is related to water filtration. More particularly, the present invention is related to the filtration of water by means of filters that retain solid particles, such as lint.

DESCRIPTION OF THE PRIOR ART

There are disclosed in the prior art laundering machines comprising water recirculation systems, designed to reduce the consumption of water by circulating the water through the tank. Such circulation causes lint and other solids to be carried along with the water and deposited again onto the clothes during the washing cycle. Consequently, filters for lint and other solids came to be used in the path traveled by the water during recirculation, causing the same to be retained and preventing the return thereof to the tank.

The filters used in those machines may either be of a removable type, whereby the user performs periodical cleanings thereof, or non-removable, in which case the machine comprises a self-cleaning system for that purpose. In patents US 3,727,435 and US 3,282,427, for example, there are disclosed self-cleaning filters applied to laundry machines.

Additionally, document No. WO2012/061880 discloses a self- cleaning filter for a laundering machine, the filter including a filter element of a preferred cylindrical shape, and three ports, to wit, (i) a first port in communication with the tank; (ii) a second port in communication with the draining system (draining pump and duct); and (iii) a third port in communication with the recirculation system (recirculation pump and duct). The filter allows the passage of water between the first and second ports bypassing the filter element, and the passage between the third port and the other ports only passing through the filter element. Therefore, the lint is retained in the filter element during recirculation of the water and flushed to the draining duct upon the draining pump being switched on. A one-way valve is further provided near the port for the draining duct (second port) to prevent the reflux of drained water containing lint back to the filter.

Notwithstanding the practical aspect of the system with a self- cleaning filter described in document WO2012/061880, this technique entails waste, since during a washing cycle a part of the water carrying lint and other residue must be drained from time to time and thereupon is not returned to the washing cycle. Also, if the frequency of draining for removal of lint is reduced, thus reducing the waste of water, there will occur an accumulation of lint in the filter element with a consequent reduction of water flow rate in the recirculation system Still referring to the prior art, with this type of constructive arrangement, during the course of the washing cycle, a large amount of lint and other solids accumulates in a recirculation filter element, reducing the flow rate in the recirculation system. Thus, the flow rate of the recirculation pump lessens, causing an increasing accumulation of washing water within the tank. As described in document WO2012/061880, such problem can be solved by turning off the recirculation pump for a certain amount of time, such that the water contained in the recirculation duct may flow back due to the hydrostatic pressure difference, thereby dislodging the lint from the recirculation filter element. Subsequently, a draining pump may be turned on for a few moments, to allow any lint present in the washing water near the recirculation filter element to be removed by drainage. In this manner, the lint-containing volume of water thus removed does not return to the system, as it is eliminated when the tank is drained. At each cycle of removal of water containing lint as described above, approximately 500 ml of water is pumped into the draining duct and therefrom flushed from the machine. Since it may be necessary to repeat the cycle of removal of lint-containing water several times during a full cloth washing cycle, a large amount of water can be wasted.

Document No. BR102012021660, in the name of the same Applicant, proposes a partial solution for the problem identified in WO2012/061880 by providing a fluid lines system comprising: (i) a one-way valve located between the recirculation line and the drainage duct, (ii) a second filter located downstream of the one-way valve and (iii) a return duct to allow water pumped and retained downstream from the one-way valve to flow back into the recirculation line after being filtered by the second filter (see Figures 1 to 4 of BR102012021660). However, the solution proposed in BR102012021660 still does not allow all the water to flow back into the recirculation line, since part of that water will be caught between the second filter and the one-way valve. Furthermore, several components are required in order that the system may operate adequately, namely a second filter, a one-way valve and a return duct.

Thus, there is a need of a device to improve on the technique described by the above cited documents in order to warrant the removal of lint and other solids from the water recirculation cycle in an efficient manner, allowing the return of all the water pumped out of the recirculation line. OBJECTS OF THE INVENTION

A first object of the present invention is the provision of a device capable of allowing the passage of liquid and solids in one direction, while only allowing liquid to flow back in the opposite direction, thereby retaining the solid materials.

A second object of the present invention is the provision of a method and a fluid lines system in a laundry machine for the purpose of avoiding waste of water on automatic filtering of solids in a process of washing by recirculation.

A third object of the present invention is the provision of a method and a fluid lines system in a laundry machine having a simplified design, operating with a reduced number of component parts.

The cited objects and further advantages of the present invention will become clearer from the description that follows and from the attached drawings.

BRIEF DESCRIPTION OF THE INVENTION

In order to fulfill the objects described above, the present invention provides a device for unidirectional retention of solids for fluids, comprising at least one filter element that (i) allows the passage of fluid and solids in a first direction, (ii) allows the return of fluid in a second direction, opposite the first direction and (iii) prevents the return of solids in the second direction.

In order to fulfill the objects described above, the present invention provides a fluid lines system for laundry machines, the system comprising a recirculation line in communication with a drainage duct provided with at least one draining pump, the system additionally comprising a device for unidirectional retention of solids for fluids, as defined above, positioned in the said drainage duct.

The present invention further provides a method in a fluid lines system of a laundry machine comprising the steps of: (i) recirculating the fluid, by means of the recirculation pump, such that undesired particles and lint in suspension be retained by the recirculation filter element, (ii) turning off the recirculation pump to allow water contained in the recirculation duct to flow back to the intermediate duct and to the tank in the recirculation fluid line to dislodge solids retained in the recirculation filter element, (iii) draining fluid, using a draining pump, for a predetermined time "t" to allow fluid containing suspended solids to be pumped to the drainage duct passing through the retention device, (iv), turning off the draining pump and returning the fluid in the drainage duct from the portion upstream of the retention device to the portion downstream thereof, filtering the solids by way of a filter element, (v) repeating steps "i" to "iv" at least once and (vi) draining the fluid contained in the strainer/tank assembly, using a draining pump, removing from the drainage duct and from the retention device lint and undesired particles retained in step 'iv".

DESCRIPTION OF THE FIGURES

The detailed description provided further along herein bears reference to the attached figures, wherein:

- Figure 1 is an isometric cutaway illustration of the device according to the preferred embodiment of the present invention;

- Figure 2a is an exploded isometric view of a housing of the O

device of Figure 1;

- Figure 2b is a top view of a filter element of the device of

Figure 1;

- Figures 3a and 3b are schematic views in longitudinal section of the device of Figure 1 in operation, with a filter element in the open and closed positions, respectively;

- Figure 4 shows a laundry machine comprising the device of Figure 1 and a fluid lines system according to a first embodiment of the present invention;

- Figure 5 shows a laundry machine comprising the device of

Figure 1 and a fluid lines system according to a second embodiment of the present invention;

- Figure 6a shows a filter arrangement according to a preferred embodiment of the present invention with a recirculation system in operation;

- Figure 6b shows the filter arrangement of Figure 5a with a drainage system in operation.

DETAILED DESCRIPTION OF THE INVENTION

The description to follow will be based on a preferred embodiment of the invention. As will be obvious to any individual skilled in the art, however, the invention is not limited to such specific embodiment. Additionally, the description of document BR102012021660 will be incorporated herein for reference purposes.

Figures 1 to 3 show different views of the device for unidirectional retention of solids 100 for fluids in accordance with a preferred embodiment of the present invention. As shown, the device comprises a filter element 110 and, preferentially, a first port 120a, a second port 120b and a ^ housing 130. The fluid, which preferentially consists in water, is able to cross the solids retention device 100 both in the direction from the first port 120a to the second port 120b, and in the opposite direction. Preferentially, the ports establish communication of the solids retention device 100 with two sides of a water pipe (not shown).

The filter element 110, which is positioned between the first port 120a and the second port 120b, consists, in a preferred embodiment, in a flexible membrane secured at one end thereof 111 to the housing 130 of the retention device 100. The housing 130 is preferably made up of two parts, namely an upper part 130a and a lower part 130b. Thus, the filter element 110 may have its end 111 secured between the upper part 130a and the lower part 130b preferably by means of at least one pin 140 of the lower part 130b fitting into at least one hole 112 of the filter element 110. After engagement of the holes 112 by the pins 140, the upper part 130a may be fitted to the lower part 130b, and the upper part preferably comprises at least one housing 150 to receive the pins 140. In this manner, the end portion 111 of the filter element 110 is interposed between the upper part 130a and a lower part 130b of the housing 130 and secured by the pins 140, allowing an easy removal and replacement thereof whenever necessary.

The lower part 130b of the housing has a diameter that is smaller than the diameter of the filter element 110. Thus, in its natural position, the same lies supported against a surface 160 of the lower part 130b, closing the passage through the retention device 100. More specifically, the filter element 110 may lie supported against a circular ledge 161 of surface 160.

Since the filter element 110 is flexible, and therefore movable with relation to the end portion 111 thereof, it allows the passage of water and solids in the direction from the second port 120b to the first port 120a, that is, from the lower part 130b to the upper part 130a of the housing 130. This passage is allowed since the filter element 110 bends under the pressure of the water being pumped in that direction, as shown in Figure 3a. Once the pumping has ceased, as shown in Figure 3b, the filter element 110 returns to its closed position (natural position), where the weight of the water above the level where it is located contributes towards maintaining it in such position. There is provided a means to allow the return of water to the lower part through the filter element 110, such means consisting in at least one recess 162 provided in the circular ledge 161 of surface 160. Thus, since the recesses 162 correspond to very small water passage pathways, the solids will be retained above the filter element 110, while the water will be able to slowly return to the lower part through the cited recesses 162.

Whenever water is once again pumped upwards, the filter element 110 will once again open while the pressure in the lower part is higher than that of the upper part, allowing a further amount of water with solids to be carried to the part located above the said filter element 110. When the pumping stops, the filter element 110 returns once again to its closed position. The water retained in the upper part will again return by gravity to the lower part and the solids will stay retained above the filer element 110. Thus, with each pumping cycle, an increasing amount of solids will keep accumulating above the filter element 110, with the pumped water always returning.

Alternatively, the filter element 110 may consist in a permeable membrane, allowing the return of water through the same. In this embodiment, the recesses 162 may be present or not, since the filter element 110 itself will already constitute a pathway for the passage of water when the same is in the closed position.

Optionally there may be provided alignment pins 180 in the lower part 130b for engagement into alignment holes 181 of the upper part 130a in order to warrant the first fitting engagement and the alignment of the arrangement at the time of assembly.

Further optionally, the lower part 130b fits into engagement with the upper part 130a by means of lateral fasteners that may allow an easy disassembly of the arrangement, such as locking tabs 170, screws (not shown), etc. Alternatively, the entire retention device 100 is made in the form of a single component. In such case, the entire arrangement should be replaced at the time of eventual maintenance.

The device for unidirectional retention of solids 100 for fluids as recited above may be used, for example, in a fluid lines system similar to that of BR102012021660, providing thereto a significant improvement in terms of the amount of water saved during the automatic process of lint removal of the recirculation cycle of a laundry machine. Such system is described below.

In Figure 4 there is shown a schematic cutaway view of a laundry machine 10 comprising a fluid lines system according to a preferred embodiment of the present invention. As may be noted, the laundry machine 10 in which the present system is applied preferably comprises a tank or bowl 12 and a strainer or basket 14 wherein the clothes are washed. The laundry machine 10 may comprise a system of washing by recirculation, in which the wash water is initially drained from the strainer 14 into the tank 12 wherefrom it subsequently proceeds to the intermediate duct 16 through an outlet of the tank 18. The recirculation system comprises a recirculation duct 20, originating from the intermediate duct 16, a recirculation pump 22, which pumps the drained water back into the strainer 14, and optionally a recirculation filer element 24, which retains solids present in the water, such as lint, avoiding the ingress thereof into the recirculation duct 20 and their consequent return to the clothes contained in the strainer 14. For descriptive purposes, a recirculation line may be defined as starting at the tank 12, proceeding along the intermediate duct 16, then through the recirculation filter element 24, following along the recirculation duct 20 and returning to the strainer 14, and subsequently to the tank 12. Additionally, a drainage line may be defined as starting at the tank 12, proceeding along the intermediate duct 16 and ending in a drainage duct 25.

The retention device 100 in accordance with the present invention is provided in the drainage duct 25, in order to retain the lint in this duct, that is, out of the recirculation line. A draining pump 28 is also provided downstream from the point of communication between the intermediate duct 16 and the recirculation duct 20, preferably in the drainage duct 25. Thus, the embodiment proposed above allows all the water containing lint that is pumped into the drainage duct 25 to be returned filtered, that is, devoid of lint, into the recirculation line, since the lint will be retained in the drainage duct by the retention device 100. Thus, the returning filtered water is once again used in the washing cycle and may be recirculated again through the recirculation system. The use of the retention device 100 in the drainage duct 25 obviates the need of an additional filter, a return duct and a one-way valve described in document BR102012021660. In the case of the filter element 24, for example, the first port

36a is the inlet from the intermediate duct 16 or directly from the tank 12. The second port 36b is the outlet to the one-way valve, and consequently to the drainage duct 25. The third port 36c is the outlet to the recirculation duct 20. Thus, when the recirculation system is in operation (Figure 6a), the lint is retained in the filter element 24, since from the first port 36a to the third port 36c the water must necessarily pass across the filter element 24. When the draining pump 28 is turned on (Figure 6b), the water follows a non-filtering path from the first port 36a to the second port 36b, carrying the lint to the drainage duct 25 and cleaning the filter element 24. This filter arrangement is applied in the embodiment shown in Figure 5.

Figures 6a and 6b show detailed illustrations of the embodiment that may be applied to the filter element 24. A housing 35 is provided with a preferred cylindrical cross section and comprising a first port 36a, a second port 36b and a third port 36c. The filter elements 24 (which are merely thin mesh screens that allow the passage of water and retain solids in suspension) also have a preferred cylindrical shape, dividing the inside of the housing 35 and allowing the provision of a non-filtering path (Figure 6b) between the first port 36a and the second port 36b, and the provision of a filtration path (Figure 6a) between the first port 36a and the third port 36c. In this manner, the first port 36a and the second port 36b are positioned in a first side (internal side) of the filter element 24, and the third port 36c is positioned in a second side (external side) of the filter element 24. All possible variants of the filter arrangement described in document WO 2012/061880 are also incorporated herein. For example, the ports 36a, 36b and 36c described above may be located in any positions in the housing 24a, provided that the water will have to pass across the filter element 24 in order to proceed from the first port 36a to the third port 36c, without having to pass across the same to flow out the second port 36b.

By associating the recirculation filter element 24 with the retention device 100, the present invention further provides a method in a fluid lines system of a laundry machine 10, comprising the steps of: i) recirculating the fluid, by means of the recirculation pump 22, such that undesired particles and lint in suspension be retained by the recirculation filter element 24; ii) turning off the recirculation pump 22 to allow the water contained in the recirculation duct 20 to return to the intermediate duct 16 and to the tank 12 in the recirculation fluid line in order to dislodge solids retained in the recirculation filter element 24; iii) draining fluid, by means of a draining pump 28, for a predetermined length of time "t" so as to allow fluid containing suspended solids to be pumped into the drainage duct 25 passing through the retaining device 100; iv) turning off the draining pump 28 and returning the fluid in the drainage duct 25 from the portion located upstream of the retention device 100 to the portion located downstream the same, filtering the solids by means of a filter element 110; v) repeating steps "i" to "iv" at least once; and vi) draining the fluid contained in the strainer/tank assembly, by means of a draining pump 28, removing from the drainage duct 25 and from the retention device 100 the lint and undesired particles retained during step "iv".

The predetermined fluid drainage time "t", that is, the time during which the draining pump is driven, is comprised within a time interval between 0.1 and 5s. Preferably, the predetermined fluid drainage time "t" is Is.

Many variations of the instant application are possible within the scope of protection hereof. Therefore, there is hereby stressed the fact that that the present invention is not limited to the specific configurations/embodiments described above.

Claims

1. Device for unidirectionally retaining solids (100) intended for fluids, characterized by comprising at least one filtering element (1 10) which:

allows passage of fluid and solids in a first direction;

allows return of fluid in a second direction; and prevents return of solids in the second direction.

2. Device, according to claim 1, characterized in that said filtering element (110) is a flexible membrane which moves between an opened position and a closed position.

3. Device, according to claim 2, characterized in that said flexible membrane is permeable.

4. Device, according to any one of claims 1 to 3, characterized in that said filtering element (1 10) has an end (11 1) fixed with respect to a housing (130) of the retaining device (100).

5. Device, according to claim 4, characterized in that said housing (130) is constituted of an upper part (130a) and a lower part (130b).

6. Device, according to claim 5, characterized in that said end (1 11) is interposed between the upper part (130a) and the lower part (130b).

7. Device, according to any one of claims 4 to 6, characterized in that said end (111) comprises at least one hole (112) which receives at least one pin (140) of the housing (130).

8. Device, according to any one of claims 2 to 7, characterized in that said filtering element (110) lies onto a surface (160).

9. Device, according to claim 8, characterized in that said surface (160) comprises at least one recess to allow water passage when the filtering element (110) is in the closed position.

10. Device, according to any one of claims 2 to 7, characterized in that said filtering element (110) lies onto circular ledge (161).

1 1. Device, according to claim 10, characterized in that said circular ledge (161) comprises at least one recess (162) to allow water passage when the filtering element (110) is in the closed position.

12. Device, according to claim 5 or 6, characterized in that said upper part (130a) and said lower part (130b) are connected by means of at least one of locking tab (170) and bolts.

13. Device, according to claim 5, 6 or 12, characterized in that said upper part (130a) and said lower part (130b) comprise alignment pins (180) and alignment holes (181).

14. Flow line system for laundry machines (10), the system comprising a recirculation flow line in communication with a drainage duct (25) having at least one drainage pump (28), characterized by further comprising a device for unidirectionally retaining solids (100) intended for fluids as defined in any one of claims 1 to 13 positioned on said drainage duct (25).

15. System, according to claim 14, characterized in that said recirculation flow line comprises a recirculation filtering element (24).

16. System, according to claim 14 or 15, characterized in that said recirculation flow line comprises a recirculation pump (22).

17. System, according to any one of claims 14 to 16, characterized in that said recirculation filtering element (24) is comprised in a filter arrangement which further comprises:

a housing (35) surrounding the filtering element (24, 32);

a first (36a), a second (36b) and a third (36c) ports,

in which the first (36a) and the second (36b) port are located on a first side of the filter element (24, 32), and the third (36c) port is located on a second side of the filter element (24, 32).

18. System, according to claim 17, characterized in that the filtering element (24, 32) divides the interior of the housing (24a, 32a) providing an unfiltered liquid path between the first (36a) and the second (36b) ports, and a filtered liquid path between the first (36a) and the third (36c) ports.

19. Method in a flow line system for laundry machines (10), characterized by comprising the steps of:

i) recirculating fluid by means of a recirculation pump (22) in a way that undesired particles and lint in suspension be retained by the recirculation filtering element (24);

ii) turning off the recirculation pump (22) so as to allow that water inside the recirculation duct (20) return for the upstream of the first flow line for detaching retained solids on the recirculation filtering element (24);

iii) draining fluid by means of a drainage pump (28), for a predetermined time "t" so as to allow the fluid containing solids in suspension to be pumped for the drainage duct (25) going through the retaining device (100);

iv) turning off the drainage pump (28) and return the fluid in the drainage duct (25) comprised in the portion above the retaining device (100) to the portion below thereof filtering solids in a filtering element (1 10);

v) repeating steps "i" to "iv" at least once; and

vi) draining the fluid comprised inside the drum/tub assembly, by a drainage pump (28), removing from the drainage duct (25) and from the return retaining device (100) lint and undesired particles retained during step "iv".

20. Method, according to claim 19, characterized in that the predetermined time "t" of the draining step is comprised in a time range from 0,1 to 5s.

21. Method, according to claim 20, characterized in that the predetermined time "t" of the draining step is Is.