Dielectric barrier discharge fluid purification system

• US 6,811,757 B2
• Filed: 03/29/2002
• Issued: 11/02/2004
• Est. Priority Date: 04/04/2001
• Status: Expired due to Fees

• Current Assignee: Ecozone Technologies Limited
• Original Assignee: Ecozone Technologies Limited
• Inventors: Levitzky, Michael, Niv, Dror
• Primary Examiner(s): Mayekar, Kishor
• Application Number:
  US10/108,562
• Publication Number:
  US 20020153241A1
• Time in Patent Office: 949 Days
• Field of Search: 422/186.04, 204/164
• US Class Current: 422/186.04
• CPC Class Codes: H05H 1/2406 using dielectric barrier discharges, i.e. with a dielectric interposed between the electrodes
• CPC Class Codes: H05H 1/47 using corona discharges
• CPC Class Codes: H05H 2245/15 Ambient air; Ozonisers

Abstract

A dielectric barrier discharge plasma reactor device for plasma-based gas and liquid purification. The device comprises a series of electrodes arranged in rows of alternating polarity so as to form a series of triangular modules in which the spacing between adjacent electrodes is less than or equal to the diameter of an individual electrode. When an electrical power supply is connected to the electrodes, an electrical discharge is produced which reacts with the constituents of the fluid to produce activated radicals. The device further comprises a fluid swiveling device which facilitates homogenous flow of the contaminated fluid through the reactor by providing effective mixing between activated radicals and fluid, such that toxins contained in the fluid are attacked and decomposed by the radicals. A number of alternative embodiments of the fluid swiveling device are described.

Claims

1. A system for purification of contaminated fluids by use of non-thermal plasma produced by dielectric gas phase corona discharge, said system comprising:

a housing provided with a fluid inlet and a fluid outlet;

a corona discharge reactor means arranged in said housing for passage of the contaminated fluids therethrough, said reactor means comprising;

upper and lower frame elements, and

a plurality of spaced-apart oppositely charged electrodes being supported by said frame elements, arranged as a plurality of adjoining triangular modules, each of said electrodes having a conducting element surrounded by an insulating jacket, said plurality of electrodes being arranged perpendicular to said frame elements in rows of alternate polarity wherein spacing between said electrode rows of alternate polarity is less than or equal to a diameter of said electrodes; and

a fluid swiveling means in fluid communication with said corona discharge reactor means for creating and directing a turbulent flow of said fluid through said reactor,

such that when an electrical power supply is connected to said electrodes, a substantially uniformly distributed plurality of electrical microdischarges is produced,

said electrical microdischarges reacting with constituents of said fluid to produce activated radicals,

said fluid swiveling means providing high exposure of said fluid to said electrical microdischarges, such that contaminants contained in said fluid are attacked and decomposed by said radicals.

2. The system of claim 1 wherein a gap remains between said conducting element and said insulating jacket, said gap being filled with oil.

3. The system of claim 1 wherein said electrodes are open at one end, comprising a conducting end, and wherein said upper and lower frame elements each have a conducting and non-conducting portion,

wherein a first row of said electrodes has said conducting end electrically connected to said conducting portion of a first of said upper and lower frame elements, and its insulating jacket connected to said non-conducting portion of an opposing one of said frame elements,

wherein a second row of said electrodes has said conducting end electrically connected to said conducting portion of a second of said upper and lower frame elements, and its insulating jacket connected to said non-conducting portion of and opposing one of said frame elements.

4. The system of claim 1 wherein said electrodes are hollow and open-ended.

5. The system of claim 4 wherein said upper and lower frame elements are hollow each of said frame elements being provided with a plurality of holes arranged in rows for insertion and retention therein of said electrodes, wherein an electrical wire is connected between each of said electrodes and subsequent one of said electrodes of equivalent polarity.

6. The system of claim 5 wherein said hollow frame elements are filled with oil.

7. The system of claim 6 wherein said oil is passed through said hollow open-ended electrodes for cooling said electrodes.

8. The system of claim 7 wherein said passage of said oil is facilitated by a pump and heat exchange system.

9. The system of claim 1 wherein said fluid swiveling means comprises

a casing having a closed rear portion, an open front portion arranged perpendicular to a direction of flow of said fluid, and a fluid outlet;

and

a primary swiveling means and a secondary swiveling means mounted within said casing.

10. The system of claim 9 wherein said primary swiveling means comprises a first frame mounted within said open front portion of said casing and a first series of vortex chambers arranged within said first frame,

wherein each of said vortex chambers is provided with inlet channels positioned to receive incoming flow of said fluid and outlet channels arranged perpendicular to direction of said incoming fluid flow, such that said incoming fluid flow entering said vortex chambers undergoes swiveling;

and

wherein secondary swiveling means comprises a second frame mounted within said closed rear portion of said casing and a series of second vortex chambers arranged within said second frame.

11. The system of claim 9 wherein said primary swiveling means comprises a plurality of tubes, each of said tubes having an open end, a closed end and a series of apertures, said electrodes being interspersed between adjacent said tubes,

wherein a first set of said tubes serve as primary swivelers and a second set of said tubes serve as secondary swivelers, said secondary swivelers having greater length than said primary swivelers, said open ends of said primary swivelers being aligned with said closed ends of said secondary swivelers,

such that said fluid enters said open ends of said primary swivelers and exits through said apertures of said primary swiveler, passing through said interspersed electrodes,

such that said fluid enters said apertures of said secondary swiveler and exits through said open end of said secondary swiveler.

12. The system of claim 1 further provided with a micron filter positioned within said inlet of said housing, in front of said primary swiveling means, for removing particles from said fluid.

13. The system of claim 1 further provided with a blower for sucking decontaminated gas out of said housing and expelling said decontaminated gas through said fluid outlet.

14. The system of claim 1 wherein said electrodes are arranged in a series of concentric rings of increasing diameter around a central region, said central region being open at one end and closed at the other end, and wherein said swiveling means is positioned within said central region.

15. The system of claim 14 wherein said swiveling means comprises a tube having an open end positioned at said open end of said central region, a closed end positioned at said closed end of said central region, and a series of apertures situated along the length of said tube, such that said fluid enters through said open end of said tube and exits via said apertures.

16. The system of claim 15 wherein the total area of the vertical cross-sections of said apertures is greater than or equal to the area of said central tube.

17. The system of claim 15 wherein the distance between said central tube and the ring of electrodes of smallest diameter is equivalent to one quarter of the diameter of said apertures.

18. The system of claim 14 wherein said swiveling means comprises a cone having a base and a flattened end, said base being positioned at said closed end of said central region and said flattened end being positioned at said open end of said central region, said cone being further provided with turbulence wings arranged in a substantially spiral pattern around the external surface of said cone,

such that fluid entering said open end of said central region encounters said turbulence wings of said cone, and is directed into the form of a vortex and swiveled towards said electrode rings surrounding said central region.

19. A method for purification of contaminated fluid by use of non-thermal plasma produced by dielectric gas phase corona discharge, said method comprising:

providing a housing formed with a fluid inlet and a fluid outlet, a corona discharge reactor means arranged in said housing for passage of the contaminated fluids therethrough, said reactor means comprising upper and lower frame elements and a plurality of spaced-apart oppositely charged electrodes being supported by said frame elements, arranged as a plurality of adjoining triangular modules, each of said electrodes having a conducting element surrounded by an insulating jacket, said plurality of electrodes being arranged perpendicular to said frame elements in rows of alternate polarity wherein spacing between said electrode rows of alternate polarity is less than or equal to a diameter of said electrodes, and a fluid swiveling means in fluid communication with said corona discharge reactor for creating and directing a turbulent flow of said fluid through said reactor;

connecting an electrical power supply to said electrodes, such that a substantially uniformly distributed plurality of electrical microdischarges is produced; and

introducing the fluid into said fluid inlet,

such that said electrical microdischarges react with constituents of said fluid to produce activated radicals, while said fluid swiveling means provides high exposure of said fluid to said electrical microdischarges, such that contaminants contained in the fluid are attacked and decomposed by said radicals.