Method for disinfectant washing of laundry in ozone and apparatus for performing the method

Abstract

The invention relates to a method for disinfectant washing of laundry in ozone, comprising a washing step, at least one spin-drying step, and at least one rinsing step, in which the laundry is washed in water containing a detergent suitable for washing in ozone, wherein during the washing step ozone is continuously introduced into the washing solution in an amount sufficient to achieve an ozone concentration in the washing solution of at least 1 ppm, and subsequently, during the final rinsing step, ozone is introduced into the water in an amount sufficient to achieve an ozone concentration in the water of at least 1 ppm. The invention also relates to an apparatus for disinfectant washing in ozone.

Description

[0001] Method for disinfectant washing of laundry in ozone and apparatus for performing the method

[0002] Technical field

[0003] The invention relates to a method for washing laundry and to an apparatus for carrying out said method of washing.

[0004] Background Art

[0005] Industrial laundries and dry-cleaning facilities use a method of washing with water enriched with ozone, wherein the water is enriched with ozone in external devices and subsequently introduced into the washing machine during the rinsing cycle of the laundry. Ozone remains dissolved in water only for a very short time, and before it is supplied to the washing machine, a large portion decomposes, thereby reducing its effectiveness. Consequently, water enriched with ozone serves only for disinfecting the laundry during the rinsing step. In conventional washing, temperatures of 40 to 90 °C and common detergents are used, which, when in contact with ozone, produce toxic by-products that enter wastewater.

[0006] Summary of the Invention

[0007] The above-mentioned drawbacks are eliminated by a method for disinfectant washing of laundry in ozone according to the present invention, which comprises the following steps: washing and at least one rinsing step.

[0008] The essence of the invention lies in that the laundry is washed in water containing a detergent suitable for washing in ozone, wherein during the washing step ozone is continuously introduced into the washing solution in an amount sufficient to achieve an ozone concentration in the washing solution of at least 1 ppm, and subsequently, during the final rinsing step, ozone is introduced into the water in an amount sufficient to achieve an ozone concentration in the water of at least 1 ppm.

[0009] The temperature of the washing solution during washing in water containing ozone is from 23 to 27 °C.

[0010] In the washing solution, a minimum ozone concentration of 1 ppm, preferably 2 ppm, must be maintained.

[0011] During the final rinsing step, a minimum ozone concentration of 1 ppm, preferably 2 ppm, must be maintained in the water.

[0012] After the final rinsing step, a spin-drying step may follow.

[0013] The advantage of this washing method is the lower water temperature during washing, since ozone is added continuously throughout the entire washing cycle as well as during rinsing. Therefore, it is necessary to use special detergents which, when in contact with ozone, do not produce substances harmful to the environment.

[0014] Another essence of this invention is an apparatus for disinfectant washing in ozone, which comprises a washing machine suitable for washing in ozone, an ozone unit for generating ozone comprising an oxygen concentrator and an ozone generator, and a control unit for ozone generation and dosing, wherein the ozone generator is connected to the outer drum of the washing machine by a hose or a tube, wherein the hose or tube is terminated on the side of the outer drum by an injector having an ozone flow rate of 8 to 20 g per hour, preferably 10 to 18 g per hour, and a pore size of 3 to 7 pm, preferably 5 pm.

[0015] The oxygen concentrator preferably has an outlet pressure of 0.04 to 0.06 MPa. The injector according to this invention preferably comprises a porous cylindrical filter, wherein the lateral surface of the cylinder forms an area for ozone release into the outer drum of the washing machine, and wherein one base of the cylinder is provided with a connection fitting for ozone inlet adapted to be attached to the hose or tube connected to the ozone generator. The opposite base of the cylinder is preferably closed with an end cap.

[0016] According to a preferred embodiment, 30 to 35% of the lateral surface area of the cylinder comprises pores having a size of 5 pm.

[0017] Preferably, the porous filter has a length of 150 to 300 mm, more preferably 200 mm, and a diameter of 10 to 15 mm, more preferably 12 mm.

[0018] Preferably, the connection fitting for ozone inlet has a length of 40 to 80 mm, more preferably 60 mm, and a diameter of 8 to 12 mm, more preferably 10 mm.

[0019] According to a preferred embodiment, the connection fitting for ozone inlet and the porous filter are arranged coaxially.

[0020] The porous filter may be made of sintered titanium, and the connection fitting for ozone inlet and, if applicable, the end cap may be made of stainless steel.

[0021] The washing machine suitable for washing in ozone preferably comprises silicone and Viton® seals for sealing parts in contact with ozone.

[0022] According to a preferred embodiment, the porous filter has pores having a size of 5 pm, a length of 200 mm, and a diameter of 12 mm.

[0023] Brief Description of the Drawings Figure 1 shows a schematic connection of the washing machine.

[0024] Figure 2 shows an ozone injector.

[0025] Detailed description

[0026] Into an industrial washing machine suitable for washing in ozone, 28 kg of laundry and the prescribed amount of detergent suitable for washing in ozone were placed (the detergents are a combination of active substances such as nonionic surfactant, butyl glycol, hydrogen peroxide, etc.). The washing machine filled the specified amount of water and heated it to 27 °C. The ozone unit, i.e. the oxygen concentrator and the ozone generator, was started. The control unit controls the production of ozone and its dosing into the washing machine. During washing, the concentration of ozone in the washing solution was maintained at a value of 2 ppm.

[0027] Washing of Towels in Ozone:

[0028] Washing of 28 kg of towels in an industrial high-speed washing machine with a capacity of 28 kg.

[0029] 1. Step - Washing

[0030] Duration of the step: 12 minutes

[0031] Washing temperature: 27 °C

[0032] Amount of water: medium level - approx. 140 I

[0033] Detergents used:

[0034] • Ozo Wash (detergent based on nonionic surfactants) 150 ml

[0035] • Ozo Degreaser (washing enhancer based on nonionic surfactants) 100 ml • Ozo Oxi Plus (washing enhancer based on 35% hydrogen peroxide) 15 ml. Continuous supply of ozone into the water solution after reaching the set level for 12 minutes to maintain the ozone concentration in the washing solution at a value of 2 ppm. 2. Step - 1st Rinsing

[0036] Duration of the step: 3 minutes

[0037] Cold water

[0038] Amount of water: high level - approx. 168 I

[0039] Step without the use of detergents.

[0040] 3. Step - 1st Spin-drying

[0041] Duration of the step: 1.5 minutes

[0042] Spin speed: 456 rpm

[0043] Step without water in the drum.

[0044] 4. Step - 2nd Rinsing

[0045] Duration of the step: 3 minutes

[0046] Cold water

[0047] Amount of water: high level - approx. 168 I

[0048] Step without the use of detergents.

[0049] Continuous supply of ozone into the water solution after reaching the set level for 3 minutes to maintain the ozone concentration in the washing solution at a value of 2 ppm.

[0050] 5. Step - 2nd Spin-drying

[0051] Duration of the step: 6 minutes

[0052] Spin speed: 913 rpm

[0053] Step without water in the drum.

[0054] The entire apparatus, as shown in the attached figure, consists of an industrial washing machine (4) suitable for ozone washing, to which an ozone unit is connected, consisting of an oxygen concentrator (1), an ozone generator (2) and an ozone injector (3), and an external control unit (5) for controlling the ozone unit and the washing machine (4). The ozone generator (2) produces ozone from the concentrated air generated in the oxygen concentrator (1). The ozone generator is connected by a hose terminated with the ozone injector directly to the outer drum of the washing machine for supplying ozone into the inner drum of the washing machine. The connection fitting of the injector (3a) has a diameter of 3.18 mm, which is sufficient to create an ozone concentration of 2 ppm in the washing solution. The ozone unit and the washing machine are controlled by an external control unit.

[0055] The ozone injector used had the following parameters:

[0056] • design: connection fitting (3a) for ozone inlet made of stainless steel and porous filter (3b) made of sintered titanium,

[0057] • 5 pm openings (to ensure binding of O3 in water),

[0058] • filter length 250 mm,

[0059] • filter diameter 12 mm,

[0060] • achieved concentration of bound ozone in water 1.8 ppm to 2 ppm,

[0061] • the ozone injector is porous with a porosity of 5 microns on 35% of the surface of the injector.

Claims

Claims1. A method for disinfectant washing of laundry in ozone, comprising a washing step, at least one spin-drying step, and at least one rinsing step, characterized in that the laundry is washed in water containing a detergent suitable for washing in ozone, wherein during the washing step ozone is continuously introduced into the washing solution in an amount sufficient to achieve an ozone concentration of at least 1 ppm in the washing solution, and subsequently, during the final rinsing step, ozone is introduced into the water in an amount sufficient to achieve an ozone concentration in the water of at least 1 ppm.

2. The method according to claim 1, characterized in that the washing temperature is from 23 to J °C.

3. The method according to claim 1 or 2, characterized in that the ozone concentration in the washing solution is maintained at 2 ppm.

4. The method according to any one of the preceding claims, characterized in that after the washing step and / or after the first rinsing step, a spin-drying step follows.

5. The method according to any one of the preceding claims, characterized in that the ozone concentration in the water during the final rinsing step is maintained at 2 ppm.

6. The method according to any one of the preceding claims, characterized in that after the final rinsing step, a spin-drying step follows.

7. An apparatus for disinfectant washing in ozone, characterized in that it comprises a washing machine (4) suitable for washing in ozone, an ozoneunit for generating ozone comprising an oxygen concentrator (1) and an ozone generator (2), and a control unit (5) for ozone generation and dosing, wherein the ozone generator (2) is connected to the outer drum of the washing machine (4) by a hose or a tube, wherein the hose or tube is terminated on the side of the outer drum by an injector (3) having an ozone flow rate of 8 to 20 g per hour, preferably 10 to 18 g per hour, and a pore size of 3 to 7 pm, preferably 5 pm.

8. The apparatus according to claim 7, characterized in that the oxygen concentrator (1) has an outlet pressure of 0.04 to 0.06 MPa.

9. The apparatus according to claim 7 or 8, characterized in that the injector (3) comprises a porous cylindrical filter (3b), wherein the lateral surface of the cylinder forms an area for ozone release into the outer drum of the washing machine (4), and wherein one base of the cylinder is provided with a connection fitting (3a) for ozone inlet adapted to be attached to the hose or tube, and the opposite base of the cylinder is preferably closed with an end cap.

10. The apparatus according to claim 9, characterized in that 30 to 35% of the lateral surface area of the cylinder comprises pores having a size of 5 pm.

11. The apparatus according to claim 9 or 10, characterized in that the porous filter (3b) has a length of 150 to 300 mm, preferably 200 mm, and a diameter of 10 to 15 mm, preferably 12 mm.

12. The apparatus according to any one of claims 9 to 11, characterized in that the connection fitting (3a) for ozone inlet has a length of 40 to 80 mm, preferably 60 mm, and a diameter of 8 to 12 mm, preferably 10 mm.

13. The apparatus according to any one of claims 9 to 11, characterized in that the connection fitting (3a) for ozone inlet and the porous filter (3b) are arranged coaxially.

14. The apparatus according to any one of claims 9 to 13, characterized in that the porous filter (3b) is made of sintered titanium.

15. The apparatus according to any one of claims 9 to 14, characterized in that the connection fitting (3a) for ozone inlet, and preferably also the end cap, are made of stainless steel.

16. The apparatus according to any one of claims 7 to 15, characterized in that the washing machine (4) suitable for washing in ozone comprises silicone and Viton® seals for sealing parts in contact with ozone.

17. The apparatus according to any one of claims 7 to 16, characterized in that the porous filter (3b) has pores having a size of 5 pm, a length of 200 mm and a diameter of 12 mm.

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