HOUSEHOLD APPLIANCE

Abstract

The invention concerns a household appliance, the household appliance comprising: a washing chamber for washing of items to be cleaned; a water system configured to feed water to and from the washing chamber for cleaning and/or rinsing of the items therein; wherein the water system comprises a UV-treatment chamber for disinfection and/or sterilization of water to be fed to the washing chamber during operation of the household appliance, wherein the UV-treatment chamber is provided with at least a first UV-light source arranged to direct UV-light towards water present in the UV-treatment chamber. The UV-treatment chamber is further provided with at least a first UV-light reflector. The invention also concerns a method for operating a household appliance.

Claims

1. Household appliance, the household appliance comprising: a washing chamber for washing of items to be cleaned; a water system configured to feed water to and from the washing chamber for cleaning and/or rinsing of the items therein; wherein the water system comprises a UV-treatment chamber for disinfection and/or sterilization of water to be fed to the washing chamber during operation of the household appliance, wherein the UV-treatment chamber is provided with a first UV-light source arranged to direct UV-light towards water present in the UV-treatment chamber, characterized in that the UV-treatment chamber is provided with a first UV-light reflector.

2. Household appliance according to claim 1, wherein the first UV-light source is arranged to direct UV-light towards the first UV-light reflector, wherein the first UV-light source and the first UV-light reflector are arranged in relation to each other so that, when UV-light is emitted from the first UV-light source and water is present in the UV-treatment chamber, the UV-light from the first UV-light source passes through water in the UV-treatment chamber before striking the first UV-light reflector, and wherein the first UV-light reflector is arranged so that the UV-light from the first UV-light source striking the first UV-light reflector is reflected into the water present in the UV-treatment chamber.

3. Household appliance according to claim 1, wherein the first UV-light source is arranged in association with a first opening in a wall of the UV-treatment chamber, wherein the first opening is provided with a first sealed cover that at least partly is made of a UV-transparent material and that has an inner side facing the UV-treatment chamber and an outer side facing away from the UV-treatment chamber, wherein at least a part of the first sealed cover exhibits a UV-transparent zone, and wherein the first UV-light source is arranged on an outside of the first sealed cover and directed towards the UV-treatment chamber so as to direct the UV-light through the UV-transparent zone and into the UV-treatment chamber.

4. Household appliance according to claim 1, wherein the first UV-light reflector is arranged in association with a second opening in a wall of the UV-treatment chamber, wherein the second opening is provided with a second sealed cover.

5. Household appliance according to claim 4, wherein the first UV-light reflector is arranged on an inside of the second sealed cover so as to reflect UV-light before it reaches the second sealed cover.

6. Household appliance according to claim 4, wherein the second sealed cover is at least partly made of a UV-transparent material, and wherein the first UV-light reflector is arranged on an outside of the UV-transparent material so as to allow UV-light directed towards the second opening to pass through the UV-transparent material, reflect onto the first UV-light reflector and pass back through the UV-transparent material into the UV-treatment chamber.

7. Household appliance according to claim 3, wherein the UV-treatment chamber is provided with a second UV-light reflector in addition to the first UV-light reflector, wherein the second UV-light reflector is arranged in association with the first UV-light source at the first opening, and wherein the second UV-light reflector is arranged on the outside or an inside of the UV-transparent material of the first sealed cover around or at a side of the UV-transparent zone so as to, while still allowing UV-light from the first UV-light source to pass through the UV-transparent zone and into the UV-treatment chamber, allow UV-light directed towards the first opening to be reflected back into the UV-treatment chamber.

8. Household appliance according to claim 1, wherein the UV-light reflector is made of aluminium, preferably a thin layer of aluminium, such as an aluminium foil.

9. Household appliance according to claim 1, wherein the UV-light reflector is made of Teflon, preferably a thin layer of Teflon, such as a Teflon foil.

10. Household appliance according to any of the above claims claim 1, wherein the UV-transparent material is quartz glass.

11. Household appliance according to claim 1, wherein the UV-light source is configured to emit UV-light within a range that at least partly includes wavelengths between 100-280 nm (UV-C).

12. Household appliance according to any of the above claims claim 1, wherein the UV-treatment chamber forms a through-flow conduit for water.

13. Household appliance according to claim 12, wherein the first UV-light source is arranged at a wall of the UV-treatment chamber so as to direct UV-light into the UV-treatment chamber in a direction across a flow direction of the water when water flows through the UV-treatment chamber.

14. Household appliance according to claim 12, wherein also the first UV-light reflector is arranged at the wall of the UV-treatment chamber but displaced in relation to the first UV-light source with regard to a circumference of the UV-treatment chamber so that, when UV-light is emitted from the first UV-light source and water flows through the UV-treatment chamber, the UV-light from the first UV-light source passes through the water across the flow direction thereof before striking the first UV-light reflector.

15. Household appliance according to claim 1, wherein the water system comprises a recirculation system for recirculating of water to be fed to the washing chamber during operation of the household appliance, wherein the UV-treatment chamber is arranged in said recirculation system.

16. Household appliance according to claim 15, wherein the circulation system is arranged to recirculate water from the washing chamber and back to the washing chamber.

17. Household appliance according to claim 15, wherein the water system comprises a tank for storage of incoming fresh water and/or water coming from the washing chamber, wherein the recirculation system is arranged to recirculate water from the tank and back to the tank.

18. Household appliance according to claim 1, wherein the household appliance comprises a fresh water inlet and an outlet for used water, both of which being connected to the water system.

19. Household appliance according to claim 1, wherein the household appliance is a dishwasher machine.

20. Household appliance according to claim 1, wherein the household appliance is provided with a turbidity sensor arranged to sense a turbidity of water present, or water to be present or water that has been present, in the UV-treatment chamber during operation of the household appliance.

21. Method for operating a household appliance according to claim 20, the method comprising: operating the household appliance with the first UV-light source activated; receiving a signal from the turbidity sensor; determining, based on the turbidity sensor signal, whether the turbidity is above a threshold; and if the turbidity is above the threshold: deactivating the first UV-light source and/or control the water system so as to lower the turbidity in the water present or to be present in the UV-treatment chamber.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0050] In the description of the invention given below reference is made to the following figure, in which:

[0051] FIG. 1 shows a first embodiment of a household appliance according to this

[0052] FIG. 2 shows a second embodiment of a household appliance according to this disclosure;

[0053] FIGS. 3A, 3B, 4, 5 and 6 show a first embodiment of a UV-treatment chamber according to this disclosure; and disclosure;

[0054] FIGS. 7-8 show a second embodiment of a UV-treatment chamber according to this disclosure.

DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

[0055] FIG. 1 shows a first embodiment of a household appliance in the form of a dishwasher 1 comprising a (dish) washing chamber 20 that can be closed by a door 14. Upper and lower baskets 2 and upper and lower spray arms 3, 4 are arranged inside the washing chamber 20.

[0056] The dishwasher 1 further comprises water conducting pipes 5, a diverter 6, a recirculation pump 7, a heater 8, a UV-treatment chamber 9 with a UV light source 10 indicated, a filter bottom (sump) 11, a turbidity sensor 12, a control unit 13, a drain pump 15, a drain connection (main outlet) 16, tap/fresh water connection (main inlet) 17 and a water intake/inlet system 18 comprising e.g. a valve and an airbrake softener. As can be understood when studying this disclosure, all these parts are not necessary for the invention.

[0057] The dishwasher 1 thus comprises a water system configured to feed water to and from the washing chamber 20 for cleaning and/or rinsing of the items therein. This water system includes the tap/fresh water connection 17 arranged (in this example) to feed water directly to a bottom part of the washing chamber 20 and it also includes a recirculation system driven by the recirculation pump 7. In the recirculation system, water is recirculated through the water conducting pipes 5 from the sump 11, via/through the UV-treatment chamber 9 and the heater 8 to the recirculation pump 7, and further to the diverter 6 and spray arms 3, 4 back to the washing chamber 20 (and down to the sump 11).

[0058] As indicated in FIG. 1, the control unit 13 is arranged to receive signals from the turbidity sensor 12 and to control the UV light source 10. The control unit 13 is also configured to control other components of the dishwasher 1, such as the pumps 7, 15, the heater 8 and the valve in the water intake/inlet system 18, so as to control the normal operation of the dishwasher 1.

[0059] A method for operating the dishwasher 1 may comprise: [0060] operating the dishwasher 1 with the UV-light source 10 activated; [0061] receiving, by the control unit 13, a signal from the turbidity sensor 12; [0062] determining, by the control unit 13, based on the turbidity sensor signal, whether the turbidity is above a threshold; and if the turbidity is above the threshold: [0063] deactivating, using the control unit 13, the UV-light source 10 and/or controlling the water system so as to lower the turbidity in the water present or to be present in the UV-treatment chamber 9.

[0064] Lowering the turbidity in the water present in the recirculation system, i.e. for instance in the sump 11, can be achieved by discharging at least a portion of the recirculating water from the dishwasher 1 using the drain pump 15 and replacing that water with fresh water using the valve in the water intake/inlet system 18. The UV-light source 10 may be activated again when the turbidity falls below the threshold.

[0065] FIG. 2 shows a second embodiment of a household appliance according to this disclosure. The appliance of FIG. 2 is also a dishwasher 100 that is similar to the dishwasher 1 of FIG. 1 but illustrated in a more simplified manner. The principal structure and function of the dishwasher 100 of FIG. 2 is similar to the dishwasher 1 of FIG. 1 and similar components have therefore been given the same reference numbers. Also the dishwasher 100 in FIG. 2 is provided with a control unit (not shown) for controlling various components and operation of the dishwasher 100.

[0066] What mainly differs between the dishwashers 1, 100 in FIGS. 1 and 2 is that the dishwasher 100 in FIG. 2 is provided with a tap/fresh water tank 22 and that a UV-treatment chamber 19, together with a pump 21, is arranged in a recirculation system connected to the water tank 22. Water present in the water tank 22 may thus be recirculated using the pump 21 so as to be treated in the UV-treatment chamber 19 and fed back to the water tank 22.

[0067] FIG. 2 indicates that the water recirculated from and to the washing chamber 20 via the pipes 5 is fed via the water tank 22 so as to mix with any tap/fresh water present there. An alternative is to arrange a separation plate inside the water tank 22, or arrange a separate tank or flow path for the water recirculating from and to the washing chamber 20, so that only tap/fresh water is allowed to enter the water tank 22. This is particularly suitable when it is desired to disinfect the tap/fresh water before it is allowed to be fed further to the washing chamber 20 of the dishwasher 100.

[0068] The dishwasher 100 may be provided with an additional UV-treatment chamber somewhere in the recirculation system, i.e. somewhere in the water conducting pipes 5, in line with what is described in relation to FIG. 1.

[0069] Each of the schematically illustrated UV-treatment chambers 9, 19 in FIGS. 1 and 2 comprises at least a first UV-light source and at least a first UV-light reflector that may be arranged in different ways.

[0070] FIGS. 3A, 3B, 4, 5 and 6 show a first embodiment of a UV-treatment chamber 50 according to this disclosure. In this example the UV-treatment chamber 50 has a water inlet 52, a water outlet 53 and a chamber body 51 through which water flows during operation of the dishwasher 1, 100 (or at least during operation of the recirculation pumps 7 and 21). The chamber body 51 has a hexagonal cross section and is provided with six UV source/reflector units 54a-54f arranged in pairs on opposite sides of the hexagonal chamber body 51 (see FIG. 6).

[0071] Each UV source/reflector unit 54a-54f, as exemplified for a first UV source/reflector 54a in FIG. 4 (exploded view) and 5, is arranged in a corresponding opening 61a in the wall of the chamber body 51 and comprises a UV-light source 55a (with electric connections 59a), a UV-light reflector 56a in the form of a circular foil of aluminium provided with a central hole 62a that forms a UV-transparent zone allowing UV-light from the UV-light source 55a to pass through and into the chamber body 51, a cover 57a for the opening 61a, wherein the cover 57a is made of UV transparent quartz glass, and sealing 58a in the form of an O-ring for sealing the cover 57a around the opening 61a. The unit 54a is attached to the body 51 by means of snap-fitting element 60a. FIG. 5 shows the first UV source/reflector 54a put together.

[0072] Each UV-light source 55a is thus arranged on an outside of the corresponding sealed cover 57a and is directed towards the UV-treatment chamber 50 so as to direct the UV-light through the UV-transparent zone 62a and into the UV-treatment chamber 50.

[0073] Each pair of units 54a-54f are aligned with each other in an axial direction of the UV-treatment chamber 50 and also directed towards each other so that the UV-light from one unit in a one of pairs pair passes across the UV-treatment chamber 50 and, if not absorbed by the process water inside the chamber 50, hits the reflector of the other unit in the same pair of units. As exemplified in FIG. 6, the UV-light emitted by the UV source 55a in the first unit 54a hits a corresponding reflector 56d of the second unit 54d arranged in a corresponding opening 61d. Similarly, the UV-light emitted by the UV source 55d in the second unit 54d hits the reflector 56a of the first unit 54a.

[0074] The UV-light source 55a of the first UV source/reflector unit 54a may be considered to be the first UV-light source and the UV-light reflector 56d of the second UV source/reflector unit 54d can be considered to be the first UV-light reflector and thus it can be said that the first UV-light source is arranged to direct UV-light towards the first UV-light reflector.

[0075] FIGS. 7-8 show a second embodiment of a UV-treatment chamber 70 according to this disclosure. Also in this example the UV-treatment chamber 70 has a water inlet 72, a water outlet 73 and a chamber body 71 through which water flows during operation of the dishwasher 1, 100 (or at least during operation of the recirculation pumps 7 and 21). The chamber body 71 has in this case a circular cross section and is provided with three UV source/reflector units 74a-74c evenly distributed circumferentially around the chamber body 71. Each unit 74a-74c emits UV-light in a wide beam so that the UV-light is directed also towards both the two other units. In this case, the units therefore do not have to be arranged in pairs and be located directly opposite each other as in the example described above.

[0076] Each UV source/reflector unit 74a-74c, as exemplified for a first UV source/reflector 74a in FIG. 8, is arranged in a corresponding opening 81a in the wall of the chamber body 71 and comprises a UV-light source 75a arranged on a PCB 79a with connector 85a and holder/lid 86a, a cover 77a for the opening 81a, wherein the cover 77a is made of UV transparent quartz glass, a UV-light reflector 76a in the form of a rectangular foil of Teflon provided with a central hole 82a that forms a UV-transparent zone allowing UV-light from the UV-light source 75a to pass through and into the chamber body 71 (with a wide beam directed also towards the other UV source/reflector units 54b, 54c), and a sealing 88a for sealing the cover 77a around the opening 81a.

[0077] Each UV-light source 75a is thus arranged on an outside of the corresponding sealed cover 77a and is directed towards the UV-treatment chamber 70 so as to direct the UV-light through the UV-transparent zone 82a, i.e. the hole 82a in the Teflon foil 76a, and into the UV-treatment chamber 70.

[0078] The units 74a-74c are aligned with each other in an axial direction of the UV-treatment chamber 70 (which, however, is not necessary in this case as the beam of UV-light is wide) and also directed towards each other (although not directly towards each other, but sufficiently for the spread of the UV beam) so that the UV-light emitted from one unit passes across the UV-treatment chamber 70 and, if not absorbed by the process water inside the chamber 70, hits the reflector of the other units. As exemplified in FIG. 8, the UV-light emitted by the UV source 75a in the first unit 74a hits a corresponding reflector 76c of another unit 74c arranged in a corresponding opening. Similarly, the UV-light emitted by the UV source in the other unit 74c hits the reflector 76a of the first unit 74a.

[0079] The UV-light source 55a of the first UV source/reflector unit 54a may be considered to be the first UV-light source and the UV-light reflector 56d of the second UV source/reflector unit 54d can be considered to be the first UV-light reflector and thus it can be said that the first UV-light source is arranged to direct UV-light towards the first UV-light reflector.

[0080] Similar to the explanation provided above for first embodiment, any of the UV source/reflector units 74a-74c can be considered be provided with the first UV-light source any of the other UV source/reflector units 74a-74c can be considered to be provided with the first UV-light reflector so that the first UV-light source is arranged to direct UV-light towards the first UV-light reflector.

[0081] The invention is not limited by the embodiments described above but can be modified in various ways within the scope of the claims. For instance, the UV-light sources and reflectors do not necessarily have to be arranged in source/reflector units as described above but may instead form separate components. Further, the number and of sources, reflectors or source/reflector units may be varied as also the relative position between source(s) and reflector(s). The detailed structure of the components may also be modified. As to the household appliance, the dishwasher may be structured in another way than exemplified in FIGS. 1 and 2, and the household appliance may instead be a laundry machine.