A HOUSEHOLD APPLIANCE USING OZONE GAS

[0001] The present invention relates to a household appliance wherein ozone gas is used in the washing and/or drying processes.

[0002] In household appliances for example in washing machines and/or dryers or dishwashers, the use of ozone gas (O ₃ ) having disinfectant and soil removing properties is known in order to increase the effectiveness of the washing process and maintaining hygiene. By means of the ozone gas used in the washing process, detergent and water consumption is reduced and energy savings is provided since the washing process can be performed at lower temperatures. The ozone generators are operated with air supply from the outside; the oxygen gas present in the air is converted into ozone gas in the generator and delivered into the washing milieu directly as ozone gas or by dissolving in the wash water. The ozone generator has to have a large capacity in order to produce the desired amount of ozone gas and the dimensions have to be increased for increasing the capacity. The use of an ozone generator with large dimensions is not suitable for domestic type washing machines or dishwashers, resulting in installment and cost problems. Ozone generators with smaller dimensions and higher capacity are available; however, an oxygen cylinder or other additional units for enriching oxygen are required for operating these generators.

[0003] Moreover, health risks may arise in washers wherein ozone gas is used as a result of the ozone gas leaking outside of the machine and the insulation operations for preventing ozone gas leakage, this time causes the interior pressure of the machine to increase and creates safety problems.

[0004] In the patent document no JP7051500, a method and device for sterilizing clothes are explained. In the said device, ozone gas is blown onto the laundry agitated in a rotating drum by an ozone generation device and the air discharged outside the device is passed through a catalyst machine.

[0005] In the patent application no WO2007043326, in a cloth drier, or a washing machine or a washing machine with cloth drying function, ozone gas is applied in order to deodorize and sterilize the dried cloths, the ozone gas is delivered unto the dry laundry in the tub before the washing process or after the drying process.

[0006] In the patent application no WO2007143785, an ozone supply means is explained which delivers ozone gas into the wash liquid in a washing apparatus.

[0007] The aim of the present invention is the realization of a household appliance comprising an ozone generator with increased ozone gas generation capacity.

[0008] The household appliance realized in order to attain the aim of the present invention, explicated in the attached claims.

[0009] In the household appliance of the present invention, an ozone generator is used in order to maintain hygiene of the washed items and while the ozone gas generated by the ozone generator is delivered into the tub by an ozone supply line, the air required by the ozone generator for generating ozone gas is not received from the outside but received by an air supply line again from inside the tub.

[0010] In the household appliance, the ozone gas generated by the ozone generator reacts with the other substances and converts back into oxygen gas when pressurized by means of a fan and delivered into the tub through the ozone supply line. Moreover, the ozone gas, being an unstable gas converts into oxygen gas in short time , even though it is not in contact with any substances in the tub. Thus, the oxygen-rich air required by the ozone generator to generate ozone gas is created in the tub and is supplied back to the ozone generator through the air supply line. Consequently, it is not necessary to use an ozone generator with a high capacity and large dimensions or use an oxygen cylinder and similar devices in order to produce the required amount of ozone gas.

[0011] In an embodiment of the present invention, in the household appliance, the ozone gas produced in the ozone generator and flowing in the ozone supply line enters into the tub from an opening provided on the upper wall of the tub and the oxygen-rich air in the tub is discharged out of the tub from an opening again on the upper wall and farther away from the first opening, passing into the air supply line. [0012] In an embodiment of the present invention, the household appliance, is for example a washing machine, and comprises a cylindrically shaped tub in the horizontal position, a drum having perforations thereon for passing of wash water, which agitates the washed laundry by rotating inside the tub around a horizontal axis and furthermore a first opening and a second opening, situated at the upper half of the tub so as to stay above the maximum level of wash water in the tub, arranged at different points from each other such that they are close to the opposite side walls or corners of the household appliance exterior body.

[0013] In another embodiment of the present invention, the household appliance, is for example a dishwasher and comprises a tub in the shape of a rectangular prism, with a first opening and a second opening arranged on the ceiling of the tub at different points from each other such that they are close to the opposite side walls or corners of the household appliance exterior body.

[0014] In another embodiment of the present invention, the household appliance comprises a water receptacle situated outside the tub, connected to the air supply line, which collects the wash water leaking into the air supply line from the tub, for example as a result of the negative pressure created at the air outlet with the circulation caused by the drum rotating at high speed or by the ozone gas fan and prevents from reaching the ozone generator. The water collected in the water receptacle is delivered to the tub by means of a return pipe and a valve is provided on the return pipe that allows water to flow into the tub but does not allow flow in the reverse direction.

[0015] The household appliance realized in order to attain the aim of the present invention is illustrated in the attached figures, where:

[0016] Figure 1 - is the schematic view of a household appliance comprising an ozone generator.

[0017] Figure 2 - is the schematic view of a household appliance in another embodiment of the present invention.

[0018] Figure 3 - is the schematic top view of a household appliance comprising ozone inlet and discharge openings on the tub. [0019] Figure 4 - is the schematic top view of a household appliance comprising ozone inlet and discharge openings on the tub in another embodiment of the present invention.

[0020] The elements illustrated in the figures are numbered as follows:

1. Household appliance

2. Tub

3. Ozone generator

4. Air inlet

5. Ozone outlet

6. Ozone supply line

7. Air supply line

8. Fan

9. Drum

10. , 110. Opening

11. Water receptacle

12. Return pipe

13. Valve

[0021] The household appliance (1), for example a washing machine and/or dryer or a dishwasher comprises a tub (2) wherein the washing process is performed and an ozone generator (3) situated outside the tub (2) and which generates ozone gas (O ₃ ).

[0022] The ozone generator (3) comprises an air inlet (4) for the entry of air used in producing the ozone gas and an ozone outlet (5) for the exit of the ozone gas to the outside.

[0023] The household appliance (1) of the present invention comprises:

- an ozone supply line (6) with one end connected to the ozone outlet (5) and the other end to the tub (2), for delivering the ozone gas from the ozone generator (3) to the tub (2) and

- an air supply line (7), with one end connected to the air inlet (4) and the other end to the tub (2), for the feedback of oxygen - rich air (H) in the tub (2) to the ozone generator (3) (Figures 1 and 2).

[0024] The household appliance (1) furthermore comprises at least one fan (8) situated preferably near the ozone outlet (5) or air inlet (4) of the ozone generator (3), which blows the ozone gas into the tub (2) from the ozone supply line (6) and/or draws the air (H) from the tub (2) into the ozone generator (3).

[0025] In the household appliance (1) the ozone gas produced by the ozone generator (3) is delivered into the tub (2) by means of the ozone supply line (6) by pressurizing by the fan (8) and the ozone gas is converted into oxygen gas by reacting with other materials which may be oxidized such as dirt, microorganisms and heavy metals present in the environment of usage. The ozone gas, being an unstable gas is transformed into oxygen gas in a short while even without contacting any substances in the tub (2). When ozone gas is supplied into the tub (2) during washing, an oxygen-rich interior air (H) is created inside the tub (2). The fan (8), while blowing ozone gas into the tub (2) simultaneously draws the air (H) inside the tub (2) into the ozone generator (3) and a closed cycle is formed that follows the sequence of the ozone generator (3) - the ozone supply line (6) - the tub (2) - air supply line (7) - the ozone generator (3) whereby the oxygen-rich air (H) is drawn continuously to be converted into ozone gas. The oxygen-rich air (H) is supplied from the tub (2) into the ozone generator (3) by the air supply line (7) thereby the ozone gas production capacity of the ozone generator (3) is increased. For example, the 500 mg/h ozone gas production capacity of the ozone generator (3) increases by 50 % reaching the value of 750 mg/h when oxygen-rich air (H) is supplied from the tub (2) for 20 minutes during washing.

[0026] The household appliance (1) comprises a first opening (10) situated on the upper wall of the tub (2) for entry of the ozone gas delivered from the ozone supply line (6) into the tub (2) and a second opening (110) situated on the upper wall of the tub (2) to pass the oxygen-rich air (H) from the tub (2) into the air supply line (7) by leaving the tub (2) (Figures 1 - 4).

[0027] The ozone generator (3) is positioned at the upper side of the tub (2) and the level of the ozone outlet (5) is higher up with respect to the first opening (10) and similarly the level of the air inlet (4) is higher up with respect to the second opening (110). The ozone supply line (6) is connected to the ozone outlet (6) above the first opening (10) and the air supply line (7) is connected to the air inlet (4) above the second opening (110), thereby the risk of water from the tub (2) reaching and damaging the ozone generator (3) is minimized since the water in the washing milieu inside the tub (2) collects at the lower side of the tub (2) by the effect of gravity.

[0028] In an embodiment of the present invention, the household appliance (1) is, for example a washing machine, and comprises a cylindrically shaped tub (2), arranged in the horizontal position and a drum (9) having perforations (D) thereon for passing of water, that agitates the washed laundry by rotating inside the tub (2) around a horizontal axis. The household appliance (1) furthermore comprises a first opening (10) and a second opening (110), situated at the upper half of the tub (2) so as to stay above the maximum level of wash water in the tub (2), arranged at separate points from each other such that they are close to the opposite side walls or corners of the household appliance (1) exterior body (G) (Figures 3 and 4).

[0029] The ozone gas received from the ozone supply line (6) passes from the first opening (10) and enters between the tub (2) and the drum (9) and afterwards into the drum (9) through the perforations (D); after the ozone gas is used in the drum (9) and converted into oxygen gas, the oxygen-rich air (H) inside the drum (9) passes between the drum (9) and the tub (2) through the perforations (D) on the drum (9) and from here passes to the air supply line (7) from the tub (2) by way of the second opening (110).

[0030] In another embodiment of the present invention, the household appliance (1), is for example a dishwasher and comprises a tub (2) in the shape of a rectangular prism. The household appliance (1) furthermore comprises a first opening (10) and a second opening (110), situated on the ceiling of the tub (2), arranged at separate points from each other such that they are close to the opposite side walls or corners of the household appliance (1) exterior body (G) (Figures 3 and 4).

[0031] By means of the first opening (10) and the second opening (110), on the upper wall of the tub (2) at points far away from each other, mentioned in the above embodiments, the re-absorption of the ozone gas at the moment it is delivered into the tub (2) is prevented, and the contact duration of the ozone gas with the washed items, during which the ozone gas enters into the tub (2) from the first opening (10) and stays there until it leaves from the second opening (110), is prolonged. [0032] In another embodiment of the present invention, the household appliance

(I) comprises a water receptacle (11) situated outside the tub (2), connected to the air supply line (7), which collects the wash water escaping from the tub (2) into the air supply line (7), for example due to the circulation effect caused by the drum (9) rotating at high speed or as a result of the aspiration effect (negative pressure) created at the second opening (110) by the fan (8) and prevents from reaching the ozone generator (3) and a return pipe (12) with one end connected to the water receptacle (11), the other end to the tub (2) for redelivering the water collected in the water receptacle (11) to the tub (2) (Figure 2).

[0033] In this embodiment, the household appliance (1) furthermore comprises a valve (13) provided on the return pipe (12), that opens and closes in one direction, opening with the effect of water flowing from the water receptacle (11) into the tub (2) thereby allowing water to flow from the return pipe (12) into the tub (2) and closing in case the flow is in the reverse direction and preventing water flow from the return pipe (12) to the water receptacle (11) (Figure 2).

[0034] In the household appliance (1) for example the drum (9) when operates at high speed, the water that is dispersed by centrifugal force can enter the air supply line (7) together with the effect of the fan (8). In the embodiment of the present invention, the wash water collects in the water receptacle

II 1) without reaching the ozone generator (3) and returns from here into the washing milieu inside the tub (2) by means of the return pipe (12) (Figure 2). The valve (13) allows water to flow from the water receptacle (11) towards the tub (2), not allowing water flow from the tub (2) towards the water receptacle (11) thereby preventing excessive amount of water to collect in the water receptacle (11).

[0035] In the household appliance (1) of the present invention, suitable for the operations of laundry washing and/or laundry drying or dishwashing, a low cost ozone generator (3) with a low capacity and occupying less space can be used by supplying back to the ozone generator (3) the oxygen-rich air (H) which is created by the conversion of ozone and available in the washing milieu inside the tub (2). The risks that may arise due to increased pressure caused by continuous supply of gas into a closed space by the ozone generator (3) are reduced, and safety is increased since the second opening (110) at the tub (2) also functions as an exhaust outlet. The present invention is not limited by the embodiments disclosed above and a person skilled in the art can easily introduce different embodiments. These should be considered within the scope of the protection disclosed by the claims of the present invention.