Plasma reactor, production method thereof, and emission control apparatus of a vehicle

• US 20030180199A1
• Filed: 12/30/2002
• Published: 09/25/2003
• Est. Priority Date: 03/19/2002
• Status: Active Grant

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Inventors: Hong, Eun-Ki, Kim, Yone-Seung, Cho, Hyung-Jei, Jeong, Chi-Young
• Granted Patent: US 7,211,227 B2
• Time in Patent Office: Days
• US Class Current: 422/186
• CPC Class Codes: B01D 2259/818 Employing electrical discharges or the generation of a plasma
• CPC Class Codes: B01D 53/92 of engine exhaust gases exhaust or silencing apparatus for internal combustion engines, machines or engines in general, having means for purifying, rendering innocuous or otherwise treating exhaust gases F01N3/00
• CPC Class Codes: B01J 15/005 in the presence of catalytically active bodies, e.g. porous plates
• CPC Class Codes: B01J 19/088 giving rise to electric discharges for heating purposes H05B7/00; for the production of ozone C01B13/11, H01T19/00
• CPC Class Codes: B01J 2219/0835 substantially flat
• CPC Class Codes: B01J 2219/0849 Corona pulse discharge
• CPC Class Codes: B01J 2219/0896 Cold plasma
• CPC Class Codes: F01N 2240/28 a plasma reactor
• CPC Class Codes: F01N 3/0892 Electric or magnetic treatment, e.g. dissociation of noxious components electric filters F01N3/01; regeneration of exhaust filters F01N3/023; heating catalytic converters F01N3/2006
• CPC Class Codes: H05H 1/2406 using dielectric barrier discharges, i.e. with a dielectric interposed between the electrodes
• CPC Class Codes: H05H 1/2418 the electrodes being embedded in the dielectric
• CPC Class Codes: H05H 2245/15 Ambient air; Ozonisers

Abstract

The present invention relates to a plasma reactor for reducing noxious gas by using a plasma reaction, a production method for such a plasma reactor, and an emission control apparatus for reducing noxious gas contained in exhaust gas of a vehicle by use of such a plasma reactor.

Claims

1. A plasma reactor comprising:

a first dielectric member;

a second dielectric member disposed facing the first dielectric member;

a gap spacer disposed between the first and second dielectric members so that a plasma region is formed therebetween;

first and second electrode members, disposed on the first and second dielectric members, respectively, for generating a corona discharge; and

first and second lead line members connected to the first and second electrode members so that the first and second electrode members receive electric voltage from the first and second lead line members, respectively.

2. The plasma reactor of claim 1, further comprising:

first and second junction holes in opposite sides of the first and second dielectric members and the gap spacer; and

first and second lead line members inserted into the first and second junction holes, respectively.

3. The plasma reactor of claim 1, wherein each surface of the first and second dielectric members in communication with the plasma region is coated with a washcoat and at least one of an oxidization catalyst and a de-NOx catalyst.

4. The plasma reactor of claim 1, wherein each surface of the first and second dielectric members in communication with the plasma region is rough so that a flow speed of an exhaust gas is reduced.

5. The plasma reactor of claim 1, wherein a thickness of the gap spacer is in the range of two to five times the thickness of the first or second dielectric members.

6. The plasma reactor of claim 1, wherein the first and second electrode members are coated with Ag, Cu, or an Ag—

Cu alloy.

7. The plasma reactor of claim 1, wherein the first and second electrode members are Cu plates.

8. The plasma reactor of claim 1, wherein the first and second electrode members are separated from the second and first lead line members, respectively, by a distance in the range of two to five times the distance between the electrode members.

9. The plasma reactor of claim 1, wherein the first and second electrode members are of a mesh configuration, or are porous.

10. The plasma reactor of claim 1, wherein the first and second lead line members are made of Ag, Cu, or an Ag—

Cu alloy.

11. The plasma reactor of claim 1, wherein the lead line members are of an inking line.

12. The plasma reactor of claim 1, wherein the lead line members are bolted into the first and second dielectric members.

13. The plasma reactor of claim 1, further comprising a spherically shaped wire mesh disposed in a junction hole formed within the gap spacer to enhance an electrical connection to the lead line member.

14. A method for producing a plasma reactor, comprising:

preparing first and second dielectric members of a planar shape, and a plurality of gap spacers;

orienting the second dielectric member to face the first dielectric member with the gap spacer therebetween to insulate the first dielectric member from the second so that a plasma region for enabling flow of exhaust gas is formed;

forming first and second junction holes, for receiving first and second lead line members, respectively, within the first and second dielectric members and the gap spacers;

forming an electrode member at each of the first and second dielectric members; and

producing a plasma reactor cell by inserting the first and second lead line members, respectively, into the first and second junction holes so the lead line members contact corresponding electrode members.

15. The plasma reactor production method of claim 14, further comprising:

accumulating a plurality of the plasma reactor cells; and

inserting conductive material into the first and second junction holes so that voltage can be applied to the electrode members of the plurality of plasma reactor cells.

16. The plasma reactor production method of claim 14, wherein each noxious gas contacting surface of the first and second dielectric members is coated with a washcoat and at least one of an oxidization catalyst and a de-NOx catalyst.

17. The plasma reactor production method of claim 14, wherein each noxious gas contacting surface of the first and second dielectric members is rough to reduce a flow speed of an exhaust gas.

18. The plasma reactor production method of claim 14, wherein a thickness of the gap spacer is in the range of two to five times the thickness of the first or second dielectric members.

19. The plasma reactor production method of claim 14, wherein the first and second electrode members are formed by coating Ag, Cu, or an Ag—

Cu alloy on the first and second dielectric members, respectively.

20. The plasma reactor production method of claim 14, wherein the first and second electrode members are Cu plates of a predetermined thickness.

21. The plasma reactor production method of claim 14, wherein the first and second electrode members are separated from the second and first lead line members, respectively, by a distance in the range of two to five times of that between the electrode members.

22. The plasma reactor production method of claim 14, wherein the first and second electrode members are of a mesh configuration, or are porous.

23. The plasma reactor production method of claim 14, wherein the first and second lead line members are made of Ag, Cu, or an Ag—

Cu alloy.

24. The plasma reactor production method of claim 14, wherein the lead line members are of an inking line.

25. The plasma reactor production method of claim 14, wherein the lead line members are bolted into the first and second dielectric members.

26. An emission control apparatus for an engine, comprising:

a housing for receiving exhaust gas from the engine;

a plasma reactor disposed in the housing, the plasma reactor comprising;

a first dielectric member,

a second dielectric member disposed facing the first dielectric member,

a gap spacer disposed between the first and second dielectric members such that a plasma region is formed therebetween,

first and second electrode members disposed at the first and second dielectric members, respectively, for generating a corona discharge, and

first and second lead line members connected to the first and second electrode members so that the first and second electrode members transmit electric voltage from the first and second lead line members, respectively;

a mat situated between the plasma reactor and the housing;

a power supply unit, comprising;

a power source of electric power,

a transformer unit for transforming the electric power to an AC voltage of 100-1,000 Hz and 1-100 kV, and

an electric cable for outputting the transformed electric power; and

a plug for receiving the transformed electric power through the electric cable, and for transmitting the received transformed electric power to the plasma reactor.

27. The emission control apparatus for an engine of claim 26, wherein the transformer unit comprises:

a receiver for receiving the electric power from the power source;

a controller for producing a frequency-and-voltage control signal for generating a corona discharge;

a function generator for transforming the electric power to an AC voltage with a frequency of 100-1,000 Hz according to the control signal;

a transformer for boosting voltage of the electric power to a range of 1-100 kV according to the control signal; and

an output part for outputting the transformed and boosted electric power.

28. The emission control apparatus for an engine of claim 26, wherein the plug comprises:

an external plug connected to the electric cable;

a joining part, formed at a lower side of the external plug, for tightly joining the plug to the housing so that exhaust gas does not leak through the junction;

a ceramic insulator, formed at a lower side of the joining part, for preventing arcing;

an internal plug, disposed at a lower side of the ceramic insulator, for preventing sparking; and

a plug electrode, penetrating from the external plug through the internal plug, so that the plug electrode is connected to the electric cable and exposed at a lower side of the internal plug.

29. The emission control apparatus for an engine of claim 28, wherein the ceramic insulator endures, within a predetermined frequency range, at least 1.5 times the output voltage of the power supply unit.

30. The emission control apparatus for an engine of claim 28, wherein the ceramic insulator has a circular cross-section and is installed inside the plasma reactor.

31. The emission control apparatus for an engine of claim 28, further comprising an elastic member disposed at the plug electrode so that an electrical connection to the lead line member is enhanced.

32. The emission control apparatus for an engine of claim 26, wherein the housing is made of stainless steel.

33. The emission control apparatus for an engine of claim 26, wherein insulating ceramic, having a compound of alumina, is applied to a portion where the plug is installed.

34. The emission control apparatus for an engine of claim 26, wherein the mat is 3-5 mm in thickness and is made of a compound with more than 90% alumina.

35. The emission control apparatus for an engine of claim 26, wherein a thickness of the mat is more than twice the distance between the first and second electrode members.