US5284556A — Exhaust treatment system and method

Claim 1

Independent Claim 174 words

A method for reducing pollutants including NOx compounds in a moving fluid produced by a combustion source, said method comprising the steps of: providing a closed treatment chamber having a length and an input and output and a substantially open interior portion for flow of said moving fluid and comprised of a conductive material sufficient to make said treatment chamber a first electrode; providing a dielectric insulating element within said treatment chamber; placing within said dielectric insulating element conductive material sufficient to create a second electrode; generating an alternating current electric field between said first and second electrodes in the interior portion of said treatment chamber; directing said moving fluid through the interior portion of said treatment chamber and said electric field; and adjusting the frequency and strength of said electric field so that a dielectric discharge occurs while said field strength remains low enough that the temperature of said moving fluid remains in a temperature range of lower than about 1800° F. where the heat of formation of said NOx compounds is negative.

Claim 2

Independent Claim 174 words

A method for reducing pollutants including NOx compounds in a moving fluid produced by a combustion source, said method comprising the steps of: providing a closed treatment chamber having a length and an input and output and a substantially open interior portion for flow of said moving fluid and comprised of a conductive material sufficient to make said treatment chamber a first electrode; providing a dielectric insulating element within said treatment chamber; placing within said dielectric insulating element conductive material sufficient to create a second electrode; generating an alternating current electric field between said first and second electrodes in the interior portion of said treatment chamber; directing said moving fluid through the interior portion of said treatment chamber and said electric field; and adjusting the frequency and strength of said electric field so that a dielectric discharge occurs while said field strength remains low enough that the temperature of said moving fluid remains in a temperature range of lower than about 1800° F. where the heat of formation of said NOx compounds is negative.

Claim 3

Dependent Claim 41 words

The method according to claim 1, further including the step of: adjusting said treatment chamber length and said alternating currency frequency such that said moving fluid is subjected to at least eight half-cycles of said discharge while in said treatment chamber.

Claim 4

Independent Claim 158 words

A method for reducing pollutants, including NOx compounds, in a moving fluid produced by a combustion source in a closed treatment chamber having a length and a substantially open interior portion for flow of said fluid and at least one pair of electrodes separated by an insulator, said method comprising the steps of: directing said fluid through the interior portion of said chamber; applying an alternating current electrical field across said electrodes to cause a dielectric discharge to occur between said electrodes and in the interior portion of said chamber, said field having a frequency and a strength low enough that the temperature of said fluid remains in a temperature range of lower than about 1800° F. where the heat of formation of said NOx compounds is negative; and adjusting said treatment chamber length and said alternating current frequency such that said fluid is subjected to at least eight half-cycles of said discharge while in said treatment chamber.

Claim 5

Independent Claim 158 words

A method for reducing pollutants, including NOx compounds, in a moving fluid produced by a combustion source in a closed treatment chamber having a length and a substantially open interior portion for flow of said fluid and at least one pair of electrodes separated by an insulator, said method comprising the steps of: directing said fluid through the interior portion of said chamber; applying an alternating current electrical field across said electrodes to cause a dielectric discharge to occur between said electrodes and in the interior portion of said chamber, said field having a frequency and a strength low enough that the temperature of said fluid remains in a temperature range of lower than about 1800° F. where the heat of formation of said NOx compounds is negative; and adjusting said treatment chamber length and said alternating current frequency such that said fluid is subjected to at least eight half-cycles of said discharge while in said treatment chamber.

Claim 6

Dependent Claim 32 words

The method according to claim 3, wherein said first electrode comprises said treatment chamber, and said second electrode comprises a electrical conductor located inside a dielectric insulator placed within said treatment chamber.

Claim 7

Dependent Claim 19 words

The method according to claim 4, wherein a portion of the inside of said treatment chamber comprises a catalyst.

Claim 8

Dependent Claim 27 words

The method according to claim 4, further including an ultraviolet light source positioned such that said moving fluid passes through the light emitted from said light source.

Claim 9

Dependent Claim 27 words

The method according to claim 3, further including an ultraviolet light source positioned such that said moving fluid passes through the light emitted from said light source.

Claim 10

Dependent Claim 167 words

Apparatus for reducing pollutants, including NOx compounds, in a moving fluid produced by a combustion source, said apparatus comprising: a treatment chamber having an inlet and an outlet and a substantially open interior portion through which said moving fluid passes and comprised of a conductive material sufficient to form a first electrode; a tubular element within said treatment chamber positioned such that said moving fluid passes between said tubular element and said first electrode, said tubular element comprising a dielectric insulating material and having a conductive material located within said tubular element to form a second electrode; means for generating an alternating current electrical field between said first and second electrodes in the interior portion of said treatment chamber, the electrical field having a strength high enough that a dielectric discharge occurs between said electrodes, and low enough that the temperature of said moving fluid remains in a temperature range of lower than about 1800° F. where the heat of formation of said NOx compounds is negative.

Claim 11

Dependent Claim 167 words

Apparatus for reducing pollutants, including NOx compounds, in a moving fluid produced by a combustion source, said apparatus comprising: a treatment chamber having an inlet and an outlet and a substantially open interior portion through which said moving fluid passes and comprised of a conductive material sufficient to form a first electrode; a tubular element within said treatment chamber positioned such that said moving fluid passes between said tubular element and said first electrode, said tubular element comprising a dielectric insulating material and having a conductive material located within said tubular element to form a second electrode; means for generating an alternating current electrical field between said first and second electrodes in the interior portion of said treatment chamber, the electrical field having a strength high enough that a dielectric discharge occurs between said electrodes, and low enough that the temperature of said moving fluid remains in a temperature range of lower than about 1800° F. where the heat of formation of said NOx compounds is negative.

Claim 12

Dependent Claim 15 words

Apparatus according to claim 8, wherein a portion of said treatment chamber comprises a catalyst.

Claim 13

Dependent Claim 26 words

Apparatus according to claim 8, further including an ultraviolet light source positioned such that said moving fluid passes through the light emitted from said light source.

Claim 14

Dependent Claim 26 words

Apparatus according to claim 9, further including an ultraviolet light source positioned such that said moving fluid passes through the light emitted from said light source.

Claim 15

Dependent Claim 19 words

Apparatus according to claim 8, wherein said treatment chamber is cylindrical and said fluid passes longitudinally through said chamber.

Claim 16

Dependent Claim 15 words

Apparatus according to claim 12, wherein said insulating material comprises fused quartz or boron nitride.

Claim 17

Dependent Claim 40 words

Apparatus according to claim 13, wherein said treatment chamber is of a length and said electric field has a frequency such that said moving fluid is subjected to at least eight half-cycles of electric discharge while in said treatment chamber.

Claim 18

Dependent Claim 172 words

Apparatus for reducing pollutants, including NOx compounds, in a moving fluid produced by a combustion source, said apparatus comprising: a cylindrical treatment chamber comprised of an electrically conductive material sufficient to form a first electrode, said chamber having an inlet and an outlet and a substantially open interior portion for flow of said fluid and an axis; a tubular insulator structure located in said chamber along said chamber axis and passing through said chamber; a second electrode located on the inside of said tubular insulator structure; a power supply for generating an alternating current voltage; and means for applying said electrical voltage to said first and second electrodes to create an electric field within the interior portion of said chamber, said field having a strength sufficient that a dielectric discharge occurs between said first and second electrodes, but said field strength being low enough that the temperature of said fluid remains in a temperature range of lower than about 1800° F. where the heat of formation of said NOx compounds is negative.

Claim 19

Dependent Claim 172 words

Apparatus for reducing pollutants, including NOx compounds, in a moving fluid produced by a combustion source, said apparatus comprising: a cylindrical treatment chamber comprised of an electrically conductive material sufficient to form a first electrode, said chamber having an inlet and an outlet and a substantially open interior portion for flow of said fluid and an axis; a tubular insulator structure located in said chamber along said chamber axis and passing through said chamber; a second electrode located on the inside of said tubular insulator structure; a power supply for generating an alternating current voltage; and means for applying said electrical voltage to said first and second electrodes to create an electric field within the interior portion of said chamber, said field having a strength sufficient that a dielectric discharge occurs between said first and second electrodes, but said field strength being low enough that the temperature of said fluid remains in a temperature range of lower than about 1800° F. where the heat of formation of said NOx compounds is negative.

Claim 20

Dependent Claim 15 words

Apparatus according to claim 15, wherein a portion of said treatment chamber comprises a catalyst.

Claim 21

Dependent Claim 26 words

Apparatus according to claim 16, further including an ultraviolet light source positioned such that said moving fluid passes through the light emitted from said light source.

Claim 22

Dependent Claim 26 words

Apparatus according to claim 17, further including an ultraviolet light source positioned such that said moving fluid passes through the light emitted from said light source.

Claim 23

Dependent Claim 22 words

Apparatus for treating pollutants in a moving fluid according to claim 17 wherein said insulator structure comprises fused quartz or boron nitride.

Claim 24

Independent Claim 120 words

A method for reducing pollutants including NOx in a gas produced by a combustion source comprising the steps of: flowing the gas through a substantially open treatment zone defined by first and second electrodes, the first electrode being covered by an insulator; generating a cyclically varying electric field between the first and second electrodes so as to subject the gas to a plurality of cycles of the varying electric field, the varying electric field having a strength high enough to create a dielectric discharge between the first and second electrodes and low enough that the temperature of the gas remains in a temperature range of lower than about 1800° F. in which the heat of formation of NOx is negative.

Claim 25

Independent Claim 120 words

A method for reducing pollutants including NOx in a gas produced by a combustion source comprising the steps of: flowing the gas through a substantially open treatment zone defined by first and second electrodes, the first electrode being covered by an insulator; generating a cyclically varying electric field between the first and second electrodes so as to subject the gas to a plurality of cycles of the varying electric field, the varying electric field having a strength high enough to create a dielectric discharge between the first and second electrodes and low enough that the temperature of the gas remains in a temperature range of lower than about 1800° F. in which the heat of formation of NOx is negative.

Claim 26

Dependent Claim 13 words

The method of claim 20 wherein the cyclically varying electric field is sinusoidal.

Claim 27

Dependent Claim 21 words

The method of claim 20 wherein the cyclically varying electric field is of a frequency at or above approximately 300 hertz.

Claim 28

Dependent Claim 21 words

The method of claim 21 wherein the cyclically varying electric field is of a frequency at or above approximately 300 hertz.

Claim 29

Dependent Claim 24 words

The method of claim 20 further comprising the step of subjecting the gas to ultraviolet radiation as the gas flows through the treatment zone.

Claim 30

Dependent Claim 17 words

The method of claim 24 wherein the ultraviolet radiation is directed towards an ultraviolet radiation reflective surface.

Claim 31

Dependent Claim 13 words

The method of claim 20 wherein the second electrode includes a catalytic surface.

Claim 32

Dependent Claim 14 words

The method of claim 26 wherein the catalytic surface comprises rhodium, platinum or nickel.

Claim 33

Independent Claim 123 words

A method for reducing pollutants including NOx in the exhaust gas of a diesel engine comprising the steps of: flowing the exhaust gas through a substantially open treatment zone defined by first and second electrodes, the first electrode being covered by an insulator; generating a cyclically varying electric field between the first and second electrodes so as to subject the exhaust gas to a plurality of cycles of the varying electric field, the varying electric field having a strength high enough to create a dielectric discharge between the first and second electrodes and low enough that the temperature of the exhaust gas remains in a temperature range of lower than about 1800° F. in which the heat of formation of NOx is negative.

Claim 34

Independent Claim 123 words

A method for reducing pollutants including NOx in the exhaust gas of a diesel engine comprising the steps of: flowing the exhaust gas through a substantially open treatment zone defined by first and second electrodes, the first electrode being covered by an insulator; generating a cyclically varying electric field between the first and second electrodes so as to subject the exhaust gas to a plurality of cycles of the varying electric field, the varying electric field having a strength high enough to create a dielectric discharge between the first and second electrodes and low enough that the temperature of the exhaust gas remains in a temperature range of lower than about 1800° F. in which the heat of formation of NOx is negative.

Claim 35

Dependent Claim 13 words

The method of claim 28 wherein the cyclically varying electric field is sinusoidal.

Claim 36

Dependent Claim 21 words

The method of claim 28 wherein the cyclically varying electric field is of a frequency at or above approximately 300 hertz.

Claim 37

Dependent Claim 21 words

The method of claim 29 wherein the cyclically varying electric field is of a frequency at or above approximately 300 hertz.

Claim 38

Dependent Claim 25 words

The method of claim 28 further comprising the step of subjecting the exhaust gas to ultraviolet radiation as the gas flows through the treatment zone.

Claim 39

Dependent Claim 17 words

The method of claim 32 wherein the ultraviolet radiation is directed towards an ultraviolet radiation reflective surface.

Claim 40

Dependent Claim 13 words

The method of claim 28 wherein the second electrode includes a catalytic surface.

Claim 41

Dependent Claim 14 words

The method of claim 34 wherein the catalytic surface comprises rhodium, platinum or nickel.

Claim 42

Independent Claim 190 words

A method for reducing pollutants including NOx compounds in a moving fluid produced by a combustion source, said method comprising the steps of: providing a closed treatment chamber having a length and an input and output and a substantially open interior portion for flow of said moving fluid and comprised of a conductive material sufficient to make said treatment chamber a first electrode; providing a dielectric insulating element within said treatment chamber; placing within said dielectric insulating element conductive material sufficient to create a second electrode; generating an alternating current electric field between said first and second electrodes in the interior portion of said treatment chamber; directing said moving fluid through the interior portion of said treatment chamber and electric field, wherein the residence of the fluid in the treatment chamber is on the order of 15 milliseconds; and adjusting the frequency and strength of said electric field so that a dielectric discharge occurs while said field strength remains low enough that the temperature of said moving fluid remains in a temperature range of lower than about 1800° F. where the heat of formation of said NOx compounds is negative.

Claim 43

Independent Claim 190 words

A method for reducing pollutants including NOx compounds in a moving fluid produced by a combustion source, said method comprising the steps of: providing a closed treatment chamber having a length and an input and output and a substantially open interior portion for flow of said moving fluid and comprised of a conductive material sufficient to make said treatment chamber a first electrode; providing a dielectric insulating element within said treatment chamber; placing within said dielectric insulating element conductive material sufficient to create a second electrode; generating an alternating current electric field between said first and second electrodes in the interior portion of said treatment chamber; directing said moving fluid through the interior portion of said treatment chamber and electric field, wherein the residence of the fluid in the treatment chamber is on the order of 15 milliseconds; and adjusting the frequency and strength of said electric field so that a dielectric discharge occurs while said field strength remains low enough that the temperature of said moving fluid remains in a temperature range of lower than about 1800° F. where the heat of formation of said NOx compounds is negative.

Claim 44

Dependent Claim 41 words

The method according to claim 36, further including the step of: adjusting said treatment chamber length and said alternating currency frequency such that said moving fluid is subjected to at least eight half-cycles of said discharge while in said treatment chamber.

Claim 45

Independent Claim 175 words

A method for reducing pollutants, including NOx compounds, in a moving fluid produced by a combustion source in a closed treatment chamber having a length and a substantially open interior portion for flow of said fluid and at least one pair of electrodes separated by an insulator, said method comprising the steps of: directing said fluid through the interior portion of said chamber; applying an alternating current electrical field across said electrode to cause a dielectric discharge to occur between said electrodes and in the interior portion of said chamber, said field having a frequency and a strength low enough that the temperature of said fluid remains in a temperature range of lower than about 1800° F. where the heat of formation of said NOx compounds is negative; and adjusting said treatment chamber length and said alternating current frequency such that said fluid is subjected to at least eight half-cycles of said discharge while in said treatment chamber, wherein the residence of the fluid in the treatment chamber is on the order of 15 milliseconds.

Claim 46

Independent Claim 175 words

A method for reducing pollutants, including NOx compounds, in a moving fluid produced by a combustion source in a closed treatment chamber having a length and a substantially open interior portion for flow of said fluid and at least one pair of electrodes separated by an insulator, said method comprising the steps of: directing said fluid through the interior portion of said chamber; applying an alternating current electrical field across said electrode to cause a dielectric discharge to occur between said electrodes and in the interior portion of said chamber, said field having a frequency and a strength low enough that the temperature of said fluid remains in a temperature range of lower than about 1800° F. where the heat of formation of said NOx compounds is negative; and adjusting said treatment chamber length and said alternating current frequency such that said fluid is subjected to at least eight half-cycles of said discharge while in said treatment chamber, wherein the residence of the fluid in the treatment chamber is on the order of 15 milliseconds.

Claim 47

Dependent Claim 32 words

The method according to claim 38, wherein said first electrode comprises said treatment chamber, and said second electrode comprises a electrical conductor located inside a dielectric insulator placed within said treatment chamber.

Claim 48

Dependent Claim 19 words

The method according to claim 39, wherein a portion of the inside of said treatment chamber comprises a catalyst.

Claim 49

Dependent Claim 27 words

The method according to claim 39, further including an ultraviolet light source positioned such that said moving fluid passes through the light emitted from said light source.

Claim 50

Dependent Claim 27 words

The method according to claim 38, further including an ultraviolet light source positioned such that said moving fluid passes through the light emitted from said light source.

Claim 51

Dependent Claim 184 words

Apparatus for reducing pollutants, including NOx compounds in a moving fluid produced by a combustion source, said apparatus comprising: a treatment chamber having an inlet and an outlet and a substantially open interior portion through which said moving fluid passes and comprised of a conductive material sufficient to form a first electrode; a tubular element within said treatment chamber positioned such that said moving fluid passes between said tubular element and said first electrode, said tubular element comprising a dielectric insulating material and having a conductive material located within said tubular element to form a second electrode; means for generating an alternating current electrical field between said first and second electrodes in the interior portion of said treatment chamber, the electrical field having a strength high enough that a dielectric discharge occurs between said electrodes, and low enough that the temperature of said moving fluid remains in a temperature range of lower that about 1800° F. where the heat of formation of said NOx compounds is negative; wherein the residence of the fluid in the treatment chamber is on the order of 15 milliseconds.

Claim 52

Dependent Claim 184 words

Apparatus for reducing pollutants, including NOx compounds in a moving fluid produced by a combustion source, said apparatus comprising: a treatment chamber having an inlet and an outlet and a substantially open interior portion through which said moving fluid passes and comprised of a conductive material sufficient to form a first electrode; a tubular element within said treatment chamber positioned such that said moving fluid passes between said tubular element and said first electrode, said tubular element comprising a dielectric insulating material and having a conductive material located within said tubular element to form a second electrode; means for generating an alternating current electrical field between said first and second electrodes in the interior portion of said treatment chamber, the electrical field having a strength high enough that a dielectric discharge occurs between said electrodes, and low enough that the temperature of said moving fluid remains in a temperature range of lower that about 1800° F. where the heat of formation of said NOx compounds is negative; wherein the residence of the fluid in the treatment chamber is on the order of 15 milliseconds.

Claim 53

Dependent Claim 15 words

Apparatus according to claim 43, wherein a portion of said treatment chamber comprises a catalyst.

Claim 54

Dependent Claim 26 words

Apparatus according to claim 44, further including an ultraviolet light source positioned such that said moving fluid passes through the light emitted from said light source.

Claim 55

Dependent Claim 26 words

Apparatus according to claim 43, further including an ultraviolet light source positioned such that said moving fluid passes through the light emitted from said light source.

Claim 56

Dependent Claim 19 words

Apparatus according to claim 43, wherein said treatment chamber is cylindrical and said fluid passes longitudinally through said chamber.

Claim 57

Dependent Claim 15 words

Apparatus according to claim 47, wherein said insulating material comprises fused quartz or born nitride.

Claim 58

Dependent Claim 40 words

Apparatus according to claim 48, wherein said treatment chamber is of a length and said electric field has a frequency such that said moving fluid is subjected to at least eight half-cycles of electric discharge while in said treatment chamber.

Claim 59

Dependent Claim 189 words

Apparatus for reducing pollutants, including NOx compounds, in a moving fluid produced by a combustion source, said apparatus comprising: a cylindrical treatment chamber comprised of an electrically conductive material sufficient to form a first electrode, said chamber having an inlet and an outlet and a substantially open interior portion for flow of said fluid and an axis; a tubular insulator structure located in said chamber along said chamber axis and passing through said chamber; a second electrode located on the inside of said tubular insulator structure; a power supply for generating an alternating current voltage; and means for applying said electrical voltage to said first and second electrodes to create an electric field within the interior portion of said chamber, said field having a strength sufficient that a dielectric discharge occurs between said first and second electrodes, but said field strength being low enough that the temperature of said fluid remains in a temperature range of lower than about 1800° F. where the heat of formation of said NOx compounds is negative; wherein the residence of the fluid in the treatment chamber is on the order of 15 milliseconds.

Claim 60

Dependent Claim 189 words

Apparatus for reducing pollutants, including NOx compounds, in a moving fluid produced by a combustion source, said apparatus comprising: a cylindrical treatment chamber comprised of an electrically conductive material sufficient to form a first electrode, said chamber having an inlet and an outlet and a substantially open interior portion for flow of said fluid and an axis; a tubular insulator structure located in said chamber along said chamber axis and passing through said chamber; a second electrode located on the inside of said tubular insulator structure; a power supply for generating an alternating current voltage; and means for applying said electrical voltage to said first and second electrodes to create an electric field within the interior portion of said chamber, said field having a strength sufficient that a dielectric discharge occurs between said first and second electrodes, but said field strength being low enough that the temperature of said fluid remains in a temperature range of lower than about 1800° F. where the heat of formation of said NOx compounds is negative; wherein the residence of the fluid in the treatment chamber is on the order of 15 milliseconds.

Claim 61

Dependent Claim 15 words

Apparatus according to claim 50, wherein a portion of said treatment chamber comprises a catalyst.

Claim 62

Dependent Claim 26 words

Apparatus according to claim 51, further including an ultraviolet light source positioned such that said moving fluid passes through the light emitted from said light source.

Claim 63

Dependent Claim 26 words

Apparatus according to claim 52, further including an ultraviolet light source positioned such that said moving fluid passes through the light emitted from said light source.

Claim 64

Dependent Claim 22 words

Apparatus for treating pollutants in a moving fluid according to claim 52 wherein said insulator structure comprises fused quartz or boron nitride.

Claim 65

Independent Claim 137 words

A method for reducing pollutants including NOx in a gas produced by a combustion source comprising the steps of: flowing the gas through a substantially open treatment zone defined by first and second electrodes, the first electrode being covered by an insulator; generating a cyclically varying electric field between the first and second electrodes so as to subject the gas to a plurality of cycles of the varying electric field, the varying electric field having a strength high enough to create a dielectric discharge between the first and second electrodes and low enough that the temperature of the gas remains in a temperature range of lower than about 1800° F. in which the heat of formation of NOx is negative, wherein the residence of the fluid in the treatment chamber is on the order of 15 milliseconds.

Claim 66

Independent Claim 137 words

A method for reducing pollutants including NOx in a gas produced by a combustion source comprising the steps of: flowing the gas through a substantially open treatment zone defined by first and second electrodes, the first electrode being covered by an insulator; generating a cyclically varying electric field between the first and second electrodes so as to subject the gas to a plurality of cycles of the varying electric field, the varying electric field having a strength high enough to create a dielectric discharge between the first and second electrodes and low enough that the temperature of the gas remains in a temperature range of lower than about 1800° F. in which the heat of formation of NOx is negative, wherein the residence of the fluid in the treatment chamber is on the order of 15 milliseconds.

Claim 67

Dependent Claim 13 words

The method of claim 55 wherein the cyclically varying electric field is sinusoidal.

Claim 68

Dependent Claim 21 words

The method of claim 55 wherein the cyclically varying electric field is of a frequency at or above approximately 300 hertz.

Claim 69

Dependent Claim 21 words

The method of claim 56 wherein the cyclically varying electric field is of a frequency at or above approximately 300 hertz.

Claim 70

Dependent Claim 24 words

The method of claim 55 further comprising the step of subjecting the gas to ultraviolet radiation as the gas flows through the treatment zone.

Claim 71

Dependent Claim 17 words

The method of claim 59 wherein the ultraviolet radiation is directed towards an ultraviolet radiation reflective surface.

Claim 72

Dependent Claim 13 words

The method of claim 55 wherein the second electrode includes a catalytic surface.

Claim 73

Dependent Claim 14 words

The method of claim 61 wherein the catalytic surface comprises rhodium, platinum or nickel.

Claim 74

Independent Claim 140 words

A method for reducing pollutants including NOx in the exhaust gas of a diesel engine comprising the steps of: flowing the exhaust gas through a substantially open treatment zone defined by first and second electrodes, the first electrode being covered by an insulator; generating a cyclically varying electric field between the first and second electrodes so as to subject the exhaust gas to a plurality of cycles of the varying electric field, the varying electric field having a strength high enough to create a dielectric discharge between the first and second electrodes and low enough that the temperature of the exhaust gas remains in a temperature range of lower than about 1800° F. in which the heat of formation of NOx is negative; wherein the residence of the fluid in the treatment chamber is on the order of 15 milliseconds.

Claim 75

Independent Claim 140 words

A method for reducing pollutants including NOx in the exhaust gas of a diesel engine comprising the steps of: flowing the exhaust gas through a substantially open treatment zone defined by first and second electrodes, the first electrode being covered by an insulator; generating a cyclically varying electric field between the first and second electrodes so as to subject the exhaust gas to a plurality of cycles of the varying electric field, the varying electric field having a strength high enough to create a dielectric discharge between the first and second electrodes and low enough that the temperature of the exhaust gas remains in a temperature range of lower than about 1800° F. in which the heat of formation of NOx is negative; wherein the residence of the fluid in the treatment chamber is on the order of 15 milliseconds.

Claim 76

Dependent Claim 13 words

The method of claim 63 wherein the cyclically varying electric field is sinusoidal.

Claim 77

Dependent Claim 21 words

The method of claim 63 wherein the cyclically varying electric field is of a frequency at or above approximately 300 hertz.

Claim 78

Dependent Claim 21 words

The method of claim 64 wherein the cyclically varying electric field is of a frequency at or above approximately 300 hertz.

Claim 79

Dependent Claim 25 words

The method of claim 63 further comprising the step of subjecting the exhaust gas to ultraviolet radiation as the gas flows through the treatment zone.

Claim 80

Dependent Claim 17 words

The method of claim 67 wherein the ultraviolet radiation is directed towards an ultraviolet radiation reflective surface.

Claim 81

Dependent Claim 13 words

The method of claim 63 wherein the second electrode includes a catalytic surface.

Claim 82

Dependent Claim 14 words

The method of claim 69 wherein the catalytic surface comprises rhodium, platinum or nickel.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1997-02-07	1997-08-09	1998-02-08	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2001-02-07	2001-08-09	2002-02-08	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2005-02-07	2005-08-09	2006-02-08	$7700.00	Window Closed / Lapsed

Exhaust treatment system and method

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