In situ sterilization and decontamination system using a non-thermal plasma discharge

• US 20030132100A1
• Filed: 11/04/2002
• Published: 07/17/2003
• Est. Priority Date: 12/15/1999
• Status: Active Grant

• Current Assignee: Stevens Institute Of Technology, PlasmaSol Corp. (Stryker Corporation)
• Original Assignee: PlasmaSol Corp. (Stryker Corporation)
• Inventors: Babko-Malyi, Sergei, Crowe, Richard, Korfiatis, George
• Granted Patent: US 7,192,553 B2
• Time in Patent Office: Days
• US Class Current: 204/164
• CPC Class Codes: A61L 2/14 Plasma, i.e. ionised gases
• CPC Class Codes: A61L 9/22 Ionisation
• CPC Class Codes: B01D 2257/91 Bacteria; Microorganisms
• CPC Class Codes: B01D 2259/818 Employing electrical discharges or the generation of a plasma
• CPC Class Codes: B01D 53/323 by electrostatic effects or by high-voltage electric fields
• CPC Class Codes: F24F 8/20 by sterilisation
• CPC Class Codes: H05H 1/2406 using dielectric barrier discharges, i.e. with a dielectric interposed between the electrodes
• CPC Class Codes: H05H 1/2443 the plasma fluid flowing through a dielectric tube
• CPC Class Codes: H05H 2245/15 Ambient air; Ozonisers

Abstract

A sterilization and decontamination system in which a non-thermal plasma discharge device is disposed upstream of a suspension media (e.g., a filter, electrostatic precipitator, carbon bed). The plasma discharge device generates a plasma that is emitted through apertures (e.g., capillaries or slits) in the primary dielectric. Plasma generated active sterilizing species when exposed to contaminants or undesirable particulate matter is able to deactivate or reduce such matter in contaminated fluid stream and/or on objects. Thus, the undesirable contaminants in the fluid to be treated are first reduced during their exposure to the plasma generated active sterilizing species in the plasma region of the discharge device. Furthermore, the plasma generated active sterilizing species are carried downstream to suspension media and upon contact therewith deactivate the contaminants collected on the suspension media itself. Advantageously, the suspension media may be cleansed in situ. To increase the sterilization efficiency an additive, free or carrier gas (e.g., alcohol, water, dry air) may be injected into the apertures defined in the primary dielectric. These additives increase the concentration of plasma generated active sterilizing agents while reducing the byproduct of generated undesirable ozone pollutants. Downstream of the filter the fluid stream may be further treated by being exposed to a catalyst media or additional suspension media to further reduce the amount of undesirable particulate matter.

Claims

1. A sterilization and decontamination system, comprising:

a plasma discharge device having a primary dielectric with at least one aperture defined therethrough that allows the passage of plasma discharge; and

a suspension media disposed downstream of the plasma discharge device.

2. The sterilization and decontamination system in accordance with claim 1, further comprising an additive fluid injected into the aperture of the primary dielectric.

3. The sterilization and decontamination system in accordance with claim 1, wherein the plasma discharge device is a capillary dielectric configuration and the at least one aperture is a capillary.

4. The sterilization and decontamination system in accordance with claim 1, wherein the plasma discharge device is a slit dielectric configuration and the at least one aperture is a slit.

5. The sterilization and decontamination system in accordance with claim 1, wherein the additive fluid is an alcohol.

6. The sterilization and decontamination system in accordance with claim 5, wherein the alcohol is ethanol or methanol.

7. The sterilization and decontamination system in accordance with claim 1, wherein the additive fluid is water vapor.

8. The sterilization and decontamination system in accordance with claim 1, wherein the additive fluid is dry air.

9. The sterilization and decontamination system in accordance with claim 1, further comprising a catalyst media disposed downstream of the suspension media.

10. The sterilization and decontamination system in accordance with claim 1, wherein the plasma discharge is a non-thermal plasma discharge.

11. The sterilization and decontamination system in accordance with claim 1, wherein the plasma discharge is a corona discharge configuration.

12. The sterilization and decontamination system in accordance with claim 1, wherein the plasma discharge is a barrier discharge configuration.

13. A method of sterilizing and decontaminating a fluid to be treated using a plasma discharge device having a primary dielectric with at least one aperture defined therethrough, a primary electrode disposed proximate and in fluid communication with the at least one aperture, a receiving electrode disposed proximate the primary dielectric, and a suspension media disposed downstream of the plasma discharge device, the method comprising the steps of:

producing plasma generated active sterilizing species by applying a voltage differential to the primary electrode and receiving electrode to emit a plasma discharge through the at least one aperture; and

exposing the fluid to be treated to the generated active sterilizing species;

collecting particulate matter from the exposed fluid to be treated in the filter; and

cleansing the collected particulate matter from the suspension media by spraying of the suspension media with the generated active sterilizing species.

14. The method in accordance with claim 13, wherein the producing step further comprises injecting an additive fluid into the aperture of the primary dielectric.

15. The method in accordance with claim 14, wherein the additive fluid is at least one of air, alcohol or water.

16. The method in accordance with claim 13, further comprising subjecting the fluid to be treated after passing through the suspension media to a catalyst media.

17. The method in accordance with claim 13, wherein the plasma discharge device is a capillary dielectric configuration.

18. The method in accordance with claim 13, wherein the plasma discharge device is a slit dielectric configuration.

19. The method in accordance with claim 13, wherein the plasma discharge device is a barrier discharge configuration.

20. The method in accordance with claim 13, wherein the plasma discharge device is a corona discharge configuration.

21. The method in accordance with claim 13, wherein the plasma discharge device is a non-thermal plasma discharge device.

22. The method in accordance with claim 14, wherein the additive fluid is an alcohol.

23. The method in accordance with claim 22, wherein the alcohol is ethanol or methanol.

24. The method in accordance with claim 14, wherein the additive fluid is water vapor.

25. The method in accordance with claim 14, wherein the additive fluid is dry air.