Strong acid sterilizing liquid containing hypochlorous acid at a low concentration, method and apparatus for generating same, and apparatus for generating and dispensing same

• US 5,858,201 A
• Filed: 01/28/1997
• Issued: 01/12/1999
• Est. Priority Date: 07/29/1994
• Status: Expired due to Fees

• Current Assignee: Toto Limited
• Original Assignee: Toto Limited
• Inventors: Otsuka, Toshiharu, Ando, Sigeru, Takeshita, Akemi, Eki, Toshio, Miyahara, Hidetaka
• Primary Examiner(s): Phasge, Arun S.
• Application Number:
  US08/776,388
• Time in Patent Office: 714 Days
• Field of Search: 205/701, 205/742, 205/556, 205/500, 204/275, 204/228
• US Class Current: 205/701
• CPC Class Codes: A01N 59/00 Biocides, pest repellants or attractants, or plant growth regulators containing elements or inorganic compounds
• CPC Class Codes: A61K 2300/00 Mixtures or combinations of active ingredients, wherein at least one active ingredient is fully defined in groups A61K31/00 - A61K41/00
• CPC Class Codes: A61K 33/00 Medicinal preparations containing inorganic active ingredients
• CPC Class Codes: A61K 33/20 Elemental chlorine; Inorganic compounds releasing chlorine
• CPC Class Codes: A61K 33/40 Peroxides
• CPC Class Codes: C02F 1/001 Processes for the treatment of water whereby the filtration technique is of importance C02F1/44 takes precedence; construction of filters in general B01D24/00 - B01D41/00
• CPC Class Codes: C02F 1/42 by ion-exchange ion-exchange in general B01J
• CPC Class Codes: C02F 1/44 by dialysis, osmosis or reverse osmosis general membrane separation processes B01D61/00, membrane modules B01D63/00, electrodialysis C02F1/4693, combination of membrane modules and bioreactors C02F3/1268
• CPC Class Codes: C02F 1/4618 for producing "ionised" acidic or basic water
• CPC Class Codes: C02F 1/4674 with halogen or compound of halogens, e.g. chlorine, bromine
• CPC Class Codes: C02F 2001/46152 characterised by the shape or form
• CPC Class Codes: C02F 2001/46185 only anodic or acidic water, e.g. for oxidizing or sterilizing
• CPC Class Codes: C02F 2103/026 Treating water for medical or cosmetic purposes
• CPC Class Codes: C02F 2201/4612 Controlling or monitoring
• CPC Class Codes: C02F 2201/4613 Inversing polarity
• CPC Class Codes: C02F 2201/46165 Special power supply, e.g. solar energy or batteries
• CPC Class Codes: C02F 2201/4617 DC only
• CPC Class Codes: C02F 2201/4618 Supplying or removing reactants or electrolyte
• CPC Class Codes: C02F 2209/005 Processes using a programmable logic controller [PLC]
• CPC Class Codes: C02F 2209/06 pH
• CPC Class Codes: C02F 2301/022 : Laminar
• CPC Class Codes: C02F 2303/04 : Disinfection

Abstract

A strong acid sterilizing liquid containing hypochlorous acid at a low concentration consists of electrolyzed salt water, wherein the pH of the liquid is 3 or less and the concentration of the hypochlorous acid is 0.2 ppm to 2 ppm.

Claims

1. A method for generating acid sterilizing liquid comprising the steps of:

providing first and second adjacent, parallel flat wall surfaces arranged to form a channel between them having a flow direction, wherein there is no barrier between the first and second wall surfaces;

providing a positive electrode plate to form at least part of said first wall surface;

providing a slit in the first wall surface at right angles to the flow direction;

providing a negative electrode plate to form at least part of the other of said wall surfaces;

passing salt water through the channel;

electrolyzing the salt water passing through the channel; and

taking a layer of acid liquid from said electrolyzed salt water passing through the channel through the slit to provide acid sterilizing liquid.

2. A method according to claim 1, wherein a distance between the first and second wall surfaces is between about 0.2 mm and about 0.5 mm.

3. A method according to claim 1, further comprising the step of controlling electric power during said step of electrolyzing.

4. A method according to claim 1, further comprising the step of controlling a salt concentration of said salt water.

5. A method for generating acid sterilizing liquid comprising the steps of:

providing first and second adjacent, parallel flat wall surfaces arranged to form a channel between them having a flow direction, wherein there is no barrier between the first and second wall surfaces;

providing a positive electrode plate to form at least part of said first wall surface;

providing a negative electrode plate to form at least part of the other of said wall surfaces;

providing a slit in the second wall surface at right angles to the flow direction;

passing salt water through the channel;

electrolyzing the salt water passing through the channel, generating a layer of acid liquid proximal to the positive electrode, and a layer of alkaline liquid proximal to the negative electrode; and

taking the layer of alkaline liquid through the slit, whereby acid sterilizing liquid is provided by said channel.

6. A method according to claim 5, wherein a distance between the first and second wall surfaces is between about 0.2 mm and about 0.5 mm.

7. A method according to claim 5, further comprising the step of controlling electric power during said step of electrolyzing.

8. A method according to claim 5, further comprising the step of controlling a salt concentration of said salt water.

9. An apparatus for generating acid sterilizing liquid comprising:

an electrolytic cell having first and second adjacent wall surfaces forming a first channel therebetween having a flow direction, wherein there is no barrier between the first and second wall surfaces, the first wall surface having a slit formed therein at right angles to the flow direction constructed to remove a layer of acid liquid proximal to the first wall surface, a positive electrode plate forming at least part of the first wall surface, a negative electrode plate forming at least part of the second wall surface;

a second channel communicating with the slit to remove acid liquid proximal to the first wall surface;

a third channel communicating with the first channel downstream of the slit to remove alkaline liquid proximal to the second wall surface;

a salt water tank;

a fourth channel communicating between the salt water tank and the first channel to supply salt water from the tank to the first channel; and

a DC power supply operatively connected to the positive and negative electrodes to apply a voltage across the electrodes.

10. An apparatus according to claim 9, wherein a distance between said first and second wall surfaces is between about 0.2 mm and about 0.5 mm.

11. An apparatus according to claim 9, further comprising a controller operably connected to the electrode plates, which controls electric power delivered to said electrolytic cell.

12. An apparatus according to claim 9, further comprising a controller operable connected to the fourth channel, which controls a salt concentration of salt water supplied to said first channel.

13. An apparatus for generating acid sterilizing liquid comprising:

an electrolytic cell having first and second adjacent wall surfaces forming a first channel therebetween having a flow direction, wherein there is no barrier between the first and second wall surfaces, the second wall surface having a slit formed therein at right angles to the flow direction constructed to remove a layer of alkaline liquid proximal to the second wall surface, a positive electrode plate forming at least part of the first wall surface, a negative electrode plate forming at least part of the second wall surface;

a second channel communicating with the slit to remove alkaline liquid proximal to the second wall surface;

a third channel communicating with the first channel downstream of the slit to remove acid liquid proximal to the second wall surface;

a salt water tank;

a fourth channel communicating between the salt water tank and the first channel to supply salt water from the tank to the first channel; and

a DC power supply operatively connected to the positive and negative electrodes to apply a voltage across the electrodes.

14. An apparatus according to claim 13, wherein a distance between said first and second wall surfaces is between about 0.2 mm and about 0.5 mm.

15. An apparatus according to claim 13, further comprising a controller operably connected to the electrode plates, which controls electric power delivered to said electrolytic cell.

16. An apparatus according to claim 13, further comprising a controller operable connected to the fourth channel, which controls a salt concentration of salt water supplied to said first channel.

17. An apparatus for generating and dispensing acid sterilizing liquid comprising:

a non-barrier electrolytic cell having first and second adjacent wall surfaces forming a first channel therebetween having a flow direction, wherein there is no barrier between the first and second wall surfaces, a positive electrode plate forming at least part of the first wall surface, a negative electrode plate forming at least part of the second wall surface, the first wall surface having a slit formed therein at right angles to the flow direction constructed to remove a layer of acidic liquid proximal to the first wall surface;

a second channel communicating with the slit to remove acid liquid proximal to the first wall surface;

a third channel communicating with the first channel downstream of the slit to remove alkaline liquid proximal to the second wall surface;

a salt water tank;

a fourth channel communicating between the salt water tank and the first channel to supply salt water from the tank to the first channel;

a supply device which feeds salt water from the salt water tank to the non-barrier electrolytic cell;

a recovery tank connected to the third channel to recover the alkaline liquid;

a DC power supply operatively connected to the positive and negative electrodes to apply a voltage across the electrodes; and

a controller operatively connected to control the operation of the DC power supply and the supply device.

18. An apparatus according to claim 17, wherein a distance between said first and second wall surfaces is between about 0.2 mm and about 0.5 mm.

19. An apparatus according to claim 17, wherein a ration of a cross sectional area of fourth channel to the third channel is 2 to 1.

20. An apparatus according to claim 17, further comprising a palm size electrolytic cell unit including said electrolytic cell, a base unit comprising the salt water tank, the recovery tank and the supply device, the DC power supply and the controller, and a harness connecting the cell unit with the base unit, and including the third and fourth channels.

21. An apparatus according to claim 20, wherein the base unit further comprises a compartment which receives the cell unit and harness.

22. An apparatus according to claim 20, further comprising means for hooking the cell unit on the base unit.

23. An apparatus according to claim 20, further comprising a hand switch disposed on the harness and operably connected to the controller.

24. An apparatus according to claim 20, wherein said supply device is a pump operably connected to the fourth channel.

25. An apparatus according to claim 20, wherein said supply device is a compressor operably connected to pressurize liquid in the salt water tank.

26. An apparatus according to claim 25, further comprising a closing valve connected to control closing of the fourth channel.

27. An apparatus according to claim 17, further comprising a switching device which reverses a polarity of voltage applied across said electrodes.

28. An apparatus according to claim 17, further comprising an ion exchange resin disposed in said salt water tank.

29. An apparatus according to claim 17, wherein said DC power supply is a battery.

30. An apparatus according to claim 17, further comprising a spray device operably connected to the second channel.

31. An apparatus according to claim 30, wherein the sprayer further comprises a porous plate and a piezoelectric element operable connected to the porous plate.

32. An apparatus according to claim 31, wherein said porous plate comprises acid resistant material.

33. An apparatus according to claim 31, wherein an entire surface area including pores is coated with acid resistant material.

34. An apparatus according to claim 31, further comprising a spray tank disposed between an outlet of the second channel and the porous plate.

35. An apparatus according to claim 34, wherein said spray tank has a depth of between about 0.5 mm and about 1.5 mm.

36. An apparatus for generating and dispensing acid sterilizing liquid comprising:

a non-barrier electrolytic cell having first and second adjacent wall surfaces forming a first channel therebetween having a flow direction, wherein there is no barrier between the first and second wall surfaces, a positive electrode plate forming at least part of the first wall surface, a negative electrode plate forming at least part of the second wall surface, the second wall surface having a slit formed therein at right angles to the flow direction constructed to remove a layer of alkaline liquid proximal to the second wall surface;

a second channel communicating with the slit to remove alkaline liquid proximal to the second wall surface;

a third channel communicating with the first channel downstream of the slit to remove acid liquid proximal to the first wall surface;

a salt water tank;

a fourth channel communicating between the salt water tank and the first channel to supply salt water from the tank to the first channel;

a supply device which feeds salt water from the salt water tank to the first channel of the non-barrier electrolytic cell;

a recovery tank connected to the second channel to recover the alkaline liquid;

a DC power supply operatively connected to the positive and negative electrodes to apply a voltage across the electrodes; and

a controller operatively connected to control the operation of the DC power supply and the supply device.

37. An apparatus according to claim 36, wherein a distance between said first and second wall surfaces is between about 0.2 mm and about 0.5 mm.

38. An apparatus according to claim 36, wherein a ration of a cross sectional area of fourth channel to the second channel is 2 to 1.

39. An apparatus according to claim 36, further comprising a palm size electrolytic cell unit including said electrolytic cell, a base unit comprising the salt water tank, the recovery tank and the supply device, the DC power supply and the controller, and a harness connecting the cell unit with the base unit, and including the second and fourth channels.

40. An apparatus according to claim 39, wherein the base unit further comprises a compartment which receives the cell unit and harness.

41. An apparatus according to claim 39, further comprising means for hooking the cell unit on the base unit.

42. An apparatus according to claim 39, further comprising a hand switch disposed on the harness and operably connected to the controller.

43. An apparatus according to claim 39, wherein said supply device is a pump operably connected to the fourth channel.

44. An apparatus according to claim 39, wherein said supply device is a compressor operably connected to pressurize liquid in the salt water tank.

45. An apparatus according to claim 44, further comprising a closing valve connected to control closing of the fourth channel.

46. An apparatus according to claim 36, further comprising a switching device which reverses a polarity of voltage applied across said electrodes.

47. An apparatus according to claim 36, further comprising an ion exchange resin disposed in said salt water tank.

48. An apparatus according to claim 36, wherein said DC power supply is a battery.

49. An apparatus according to claim 36, further comprising a spray device operably connected to the third channel.

50. An apparatus according to claim 49, wherein the sprayer further comprises a porous plate and a piezoelectric element operable connected to the porous plate.

51. An apparatus according to claim 50, wherein said porous plate comprises acid resistant material.

52. An apparatus according to claim 50, wherein an entire surface area including pores is coated with acid resistant material.

53. An apparatus according to claim 50, further comprising a spray tank disposed between an outlet of the second channel and the porous plate.

54. An apparatus according to claim 53, wherein said spray tank has a depth of between about 0.5 mm and about 1.5 mm.