Exhaust treatment system and method

Claim 1

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 an open interior portion for flow of said moving fluid and comprised of a conductive material 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 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, the alternating current electric field comprising a series of damped sinusoidal waveforms; directing said moving fluid through the interior portion of said treatment chamber and said electric field, wherein the fluid in the treatment chamber has a residence in the range of about 1 to 200 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.

Claim 2

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 an open interior portion for flow of said moving fluid and comprised of a conductive material 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 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, the alternating current electric field comprising a series of damped sinusoidal waveforms; directing said moving fluid through the interior portion of said treatment chamber and said electric field, wherein the fluid in the treatment chamber has a residence in the range of about 1 to 200 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.

Claim 3

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 an 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., said field including a plurality of frequency components including a damped sinusoid of a first frequency and an oscillatory signal of a second frequency; 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 4

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 an 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., said field including a plurality of frequency components including a damped sinusoid of a first frequency and an oscillatory signal of a second frequency; 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 8

An 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 an open interior portion through which said moving fluid passes and comprised of a conductive material 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., the electrical field comprises a train of waveforms, said train of waveforms comprising a damped oscillatory signal.

Claim 9

An 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 an open interior portion through which said moving fluid passes and comprised of a conductive material 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., the electrical field comprises a train of waveforms, said train of waveforms comprising a damped oscillatory signal.

Claim 12

A method for reducing pollutants including NOx in a gas produced by a combustion source comprising the steps of: flowing the gas through an 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., the varying electric field comprising a series of damped oscillatory waveforms.

Claim 13

A method for reducing pollutants including NOx in a gas produced by a combustion source comprising the steps of: flowing the gas through an 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., the varying electric field comprising a series of damped oscillatory waveforms.

Claim 17

A method for reducing pollutants including NOx in the exhaust gas of a diesel engine comprising the steps of: flowing the exhaust gas through an 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., the varying electric field comprising a series of damped oscillatory waveforms.

Claim 18

A method for reducing pollutants including NOx in the exhaust gas of a diesel engine comprising the steps of: flowing the exhaust gas through an 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., the varying electric field comprising a series of damped oscillatory waveforms.