Honda Motor Co., Ltd.

Ngk Insulators, Inc.

Kenji Dosaka

Masaaki Masuda

Yasumasa Fujioka

Keizo Iwama

Takeshi Sakuma

Masanobu Miki

Yukio Miyairi

Tatsuhiko Hatano

Yoshiyuki Nakanishi

Atsuo Kondou

Yuuichiro Imanishi

Shinya Ishimaru

Atsuo Kondo

Kazuhide Terada

Kazuhiro Kondo

A plasma generating electrode includes two types of plate-shaped unit electrodes of different polarities, the two types of unit electrodes of different polarities being hierarchically and alternately stacked at specific intervals, a discharge space for generating plasma being formed between the opposing unit electrodes, each of the unit electrodes of one polarity among the two types of unit electrodes of different polarities including a plate-shaped conductor exhibiting conductivity and a ceramic dielectric disposed to cover the conductor, the ceramic dielectric of the unit electrode of one polarity including a support protrusion for forming the discharge space for generating plasma between the opposing unit electrodes and at least a part of a space in which the unit electrode of the other polarity is disposed opposite to the unit electrode of one polarity and for supporting the unit electrode of one polarity, the support protrusion being integrally formed with the ceramic dielectric on at least one surface of the ceramic dielectric on at least one end of the ceramic dielectric in one direction.

Plasma generating electrode and plasma reactor

A plasma reactor is provided with two or more plasma generating electrodes which are installed in series inside a gas passage in a casing, with each plasma generating electrode being electrically controlled independently. The surface area of the conductor on each unit electrode forming the plasma generating electrode installed on the upstream side of the gas passage is smaller than the surface area of the conductor on the unit electrode forming the plasma generating electrode installed on the downstream side of the gas passage. Plasma can be generated between each of the unit electrodes by supplying each of the plasma generating electrodes with independently controlled electric power. The plasma reactor can efficiently react specific components contained in the gas passing through the gas passage.

Plasma reactor

An exhaust gas treating apparatusincludes; a case bodyand a plasma producing meanscapable of producing plasma inside the case bodyand treats the substances to be treated contained in the exhaust gas by the plasma producing means. The plasma producing meanshas one or more each of a pulse electrodeand a ground electrodethat are oppositely disposed in the case bodyand has a pulse power sourcecapable of feeding a pulse current to the pulse electrodeby switching frequency and/or voltage for different values at predetermined time intervals. The substances to be treated contained in the exhaust gas can selectively be treated by switching frequency and/or voltage value for different values at predetermined time intervals so that plasma of a kind adequate for the substances to be treated contained in an exhaust gas is produced between the pulse electrodeand the ground electrode

Apparatus and method of treating exhaust gas

A plasma generating electrodeof the present invention includes a plurality of unit electrodeshierarchically layered at predetermined intervals, the unit electrodesincluding a deficient unit electrodein which a conductive filmhas an absent portion and a normal unit electrodein which the conductive filmdoes not have an absent portion. Spaces V formed between the unit electrodesinclude a normal space Va formed so that the distance between conductive filmscorresponds to the distance between the unit electrodesand a deficient space Vb formed so that the distance between the conductive filmsis greater than the distance between the conductive filmsin the normal space Va. The plasma generating electrodeof the present invention can efficiently treat a plurality of predetermined components contained in a treatment target fluid by utilizing different types of plasma suitable for respective reactions by causing the treatment target fluid to flow only once.

Plasma generating electrode, plasma generator, and exhaust gas purifying device

A plasma generating electrodeof the invention includes at least a pair of electrodes, at least one electrodeof the pair of electrodesincluding a plate-like ceramic bodyas a dielectric and a plurality of conductive filmsdisposed in the ceramic bodyand each having a plurality of through-holesformed through the conductive filmin its thickness direction in a predetermined arrangement pattern, the through-holeshaving a cross-sectional shape including an arc shape along a plane perpendicular to the thickness direction, an arrangement pattern of the through-holesformed in at least one conductive filmbeing different from an arrangement pattern of the through-holesformed in the other conductive film. The plasma generating electrodeis capable of simultaneously generating different states of plasma upon application of voltage between the pair of electrodesdue to the different arrangement patterns of the through-holesin the conductive films

Plasma generating electrode, plasma generation device, and exhaust gas purifying device

A plasma generating electrode of the invention present includes at least a pair of electrodesat least one electrodeof the pair of electrodesincluding a plate-like ceramic bodyas a dielectric and a conductive filmdisposed inside the ceramic plateand having a plurality of through-holesformed through the conductive filmin its thickness direction, the through-holes having a cross-sectional shape including an arc shape along a plane perpendicular to the thickness direction. The plasma generating electrode can generate uniform and stable plasma at low power consumption.

A plasma generating electrode capable of generating plasma with a high energy level by using a small amount of electric power is provided. The plasma generating electrode includes at least a pair of unit electrodes including a unit electrode as an anode and a unit electrode as a cathode, and can generate plasma by applying voltage, the unit electrode as an anode and the unit electrode as a cathode being disposed facing each other, and at least the unit electrode as an anode having a plate-like ceramic dielectric and a conductive film disposed in the ceramic dielectric, wherein the unit electrode as a cathode can emit secondary electrons in a number five times or greater than the number of cations (primary particles) which it receives when the cations produced in the process of plasma generation collide therewith.

A plasma generation electrode capable of subjecting predetermined components contained in a fluid to be treated to their respective reaction treatments with plasmas having different intensities optimized on a reaction basis, by passing merely once the fluid to be treated, is provided. In the plasma generation electrode, a unit electrode is composed of a tabular ceramic material serving as a dielectric material and an electrically conductive film disposed in the inside of the ceramic material, a plurality of unit electrodes are layered at a constant spacing, the distance between the electrically conductive films disposed in the unit electrodes adjacent to each other is varied partly or the dielectric constant of the ceramic material constituting the unit electrode is varied partly, and plasmas having different intensities can be generated partly in the spaces.

Plasma generation electrode, plasma reactor, and exhaust gas cleaning apparatus

In an exhaust gas purifying technique in which discharge is utilized, the invention provides a technique in which purification efficiency can be enhanced while an increase in electric power consumption is suppressed. A discharge mode including a discharge period and an undischarged period is adopted in a configuration in which a plasma process is performed to exhaust gas from a Diesel engine by generating the discharge in a plasma generator. A basic waveform periodically exists in a repeated manner in the discharge period, and the discharge is not performed in the undischarged period. An amplitude and/or a period of the basic waveform is controlled according to a load on the Diesel engine, a continuous iteration count of the basic waveform is controlled according to purification reaction efficiency in the plasma process, and the burst period is controlled according to an exhaust gas flow rate.

Exhaust gas purifying apparatus

An exhaust gas purification system that is equipped, from an upstream side toward downstream side through which an exhaust gas flows, with a plasma reactor and a NOselective reduction catalyst unit having a NOselective reduction catalyst layer acting on the exhaust gas, and which system provides a reducing agent adding means adding a reducing agent to the exhaust gas at an upstream side of the plasma reactor, wherein the NOselective reduction catalyst layer comprises nickel and a NOselective reduction catalyst or wherein the NOselective reduction catalyst layer contains &#x3b3;-alumina that supports magnesium or wherein the NOselective reduction catalyst unit comprises a first purification unit where an exhaust gas via the plasma reactor is introduced, and a second purification unit where an exhaust gas via the first purification unit is introduced.

Exhaust gas purification system

A system for purifying an exhaust gas includes a plasma unit and a catalyst unit. The plasma unit generates energetic plasma species which react with particulate matters and nitrogen oxides contained in the exhaust gas. The catalyst unit has a catalyst which reacts with the exhaust gas. The plasma unit is disposed upstream relative to the catalyst unit in a direction of flow of the exhaust gas and the system provides sequential purification for the particulate matters and the nitrogen oxides.

System and method for purifying an exhaust gas

An exhaust gas purification system equipped, from an upstream side toward downstream side through which an exhaust gas flows, with a plasma reactor and a catalyst unit charged with a catalyst acting on NOin the exhaust gas in this order, and equipped with a reducing agent supplying device to supply a reducing agent at an upstream side of the plasma reactor, wherein the catalyst has an NOadsorptive catalyst layer and an NOselective reduction catalyst layer contacting the NOadsorptive catalyst layer.

Growing community of inventors

Shioya-gun, Japan

Kenji Dosaka