Process for vaporizing hydrogen peroxide to sterilize surfaces

• US 6,096,265 A
• Filed: 08/09/1996
• Issued: 08/01/2000
• Est. Priority Date: 08/11/1995
• Status: Expired due to Term

• Current Assignee: Nestec SA (Nestle SA)
• Original Assignee: Nestec SA (Nestle SA)
• Inventors: Schmied, Christian, Mezger, Ulrich
• Primary Examiner(s): Eyler, Yvonne
• Assistant Examiner(s): LAZAR WESLEY, ELIANE M
• Application Number:
  US08/700,659
• Time in Patent Office: 1,453 Days
• Field of Search: 422/28, 422/27, 422/29, 422/32, 422/292, 422/298, 422/299, 422/9, 422/302, 422/306, 422/33, 422/108, 261/161, 261/99, 239/145
• US Class Current: 422/28
• CPC Class Codes: A61L 2/208 Hydrogen peroxide
• CPC Class Codes: A61L 2/24 Apparatus using programmed or automatic operation
• CPC Class Codes: B65B 55/02 Sterilising, e.g. of complete packages
• CPC Class Codes: B65B 55/10 by liquids or gases

Abstract

For sterilizing surfaces with hydrogen peroxide, a stream of hot air is fed through a tube which includes a porous section, and vaporized hydrogen peroxide is diffused from the porous section into the hot air stream to obtain a combined hot air and vaporized stream mixture for supplying the vaporized hydrogen peroxide to a surface for sterilizing the surface. Further for carrying out the process, liquid hydrogen peroxide is fed to the porous section for forming a film on the porous section, and the porous section is heated to a temperature to vaporize the hydrogen peroxide for diffusion via the porous section into the hot air stream.

Claims

1. A process for supplying hydrogen peroxide for sterilizing a surface comprising feeding a stream of hot air to and within and longitudinally through a tube which comprises a porous section and diffusing vaporized hydrogen peroxide from the porous section into the hot air stream to obtain a combined hot air and vaporized hydrogen peroxide stream mixture for supplying the vaporized hydrogen peroxide to a surface for sterilizing the surface.

2. A process according to claim 1 further comprising feeding liquid hydrogen peroxide to the porous section for forming a film on the porous section and heating the porous section to a temperature to vaporize the hydrogen peroxide for diffusion via the porous section into the hot air stream.

3. A process according to claim 2 wherein the porous section is heated to a temperature of from 110°

C. to 130°

C. for vaporizing the liquid hydrogen peroxide.

4. A process according to claim 2 wherein the porous section is heated to a temperature of around 120°

C. for vaporizing the liquid hydrogen peroxide.

5. A process according to claim 1 further comprising monitoring the combined stream mixture and measuring hydrogen peroxide concentration of the mixture.

6. A process according to claim 5 wherein the concentration is measured with a photometer.

7. A process according to claim 5 wherein the concentration is measured with a thermal catalytic decomposition catalyst.

8. A process according to claim 1 to or 2 wherein the porous section has pores having a diameter of from 20 microns to 80 microns.

9. A process according to claim 8 wherein the porous section has a thickness of from 3 mm to 4 mm.

10. A process according to claim 8 wherein the hot air stream is fed to, within and through the tube at a rate of from 20 l/min to 50 l/min and wherein the hydrogen peroxide is diffused so that the combined stream mixture has a hydrogen peroxide concentration of from 5 mg to 20 mg per liter hot air.

11. A process according to claim 10 wherein the porous section has a thickness of from 3 mm to 4 mm.

12. A process according to claim 1 or 2 wherein the porous section is a sintered metal tube.

13. A process according to claim 8, wherein the porous section has a thickness of from 3 mm to 4 mm.

14. A process according to claim 1 or 2 wherein the hydrogen peroxide is diffused so that the combined stream mixture has a hydrogen peroxide concentration of from 5 mg to 20 mg per liter hot air.

15. A process according to claim 14 wherein the hot air stream is fed to, within and through the tube at a rate of from 20 l/min to 50 l/min.

16. A process according to claim 1 or 2 wherein the tube including the porous section is maintained at a temperature on an order of 120°

C.