US20090282817A1 - Plasma processing apparatus - Google Patents

Plasma processing apparatus Download PDF

Info

Publication number
US20090282817A1
US20090282817A1 US12/435,086 US43508609A US2009282817A1 US 20090282817 A1 US20090282817 A1 US 20090282817A1 US 43508609 A US43508609 A US 43508609A US 2009282817 A1 US2009282817 A1 US 2009282817A1
Authority
US
United States
Prior art keywords
honeycomb
conductor
processing apparatus
insulator
plasma processing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US12/435,086
Other languages
English (en)
Inventor
Masaaki Masuda
Yukio Miyairi
Michio Takahashi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NGK Insulators Ltd
Original Assignee
NGK Insulators Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NGK Insulators Ltd filed Critical NGK Insulators Ltd
Assigned to NGK INSULATORS, LTD. reassignment NGK INSULATORS, LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: MASUDA, MASAAKI, MIYAIRI, YUKIO, TAKAHASHI, MICHIO
Publication of US20090282817A1 publication Critical patent/US20090282817A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H1/00—Generating plasma; Handling plasma
    • H05H1/24—Generating plasma
    • H05H1/47—Generating plasma using corona discharges
    • H05H1/471—Pointed electrodes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/32—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by electrical effects other than those provided for in group B01D61/00
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/922—Mixtures of carbon monoxide or hydrocarbons and nitrogen oxides
    • B01D53/925—Simultaneous elimination of carbon monoxide or hydrocarbons and nitrogen oxides
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/009—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more separate purifying devices arranged in series
    • F01N13/0097—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more separate purifying devices arranged in series the purifying devices are arranged in a single housing
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/0892—Electric or magnetic treatment, e.g. dissociation of noxious components
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/24—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by constructional aspects of converting apparatus
    • F01N3/28—Construction of catalytic reactors
    • F01N3/2803—Construction of catalytic reactors characterised by structure, by material or by manufacturing of catalyst support
    • F01N3/2825—Ceramics
    • F01N3/2828—Ceramic multi-channel monoliths, e.g. honeycombs
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/32431—Constructional details of the reactor
    • H01J37/32532—Electrodes
    • H01J37/32541—Shape
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/32431—Constructional details of the reactor
    • H01J37/32798—Further details of plasma apparatus not provided for in groups H01J37/3244 - H01J37/32788; special provisions for cleaning or maintenance of the apparatus
    • H01J37/32816—Pressure
    • H01J37/32825—Working under atmospheric pressure or higher
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H1/00—Generating plasma; Handling plasma
    • H05H1/24—Generating plasma
    • H05H1/48—Generating plasma using an arc
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2259/00—Type of treatment
    • B01D2259/80—Employing electric, magnetic, electromagnetic or wave energy, or particle radiation
    • B01D2259/818—Employing electrical discharges or the generation of a plasma
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2340/00—Dimensional characteristics of the exhaust system, e.g. length, diameter or volume of the apparatus; Spatial arrangements of exhaust apparatuses
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2340/00—Dimensional characteristics of the exhaust system, e.g. length, diameter or volume of the apparatus; Spatial arrangements of exhaust apparatuses
    • F01N2340/02—Dimensional characteristics of the exhaust system, e.g. length, diameter or volume of the apparatus; Spatial arrangements of exhaust apparatuses characterised by the distance of the apparatus to the engine, or the distance between two exhaust treating apparatuses
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H2245/00—Applications of plasma devices
    • H05H2245/10—Treatment of gases
    • H05H2245/17—Exhaust gases

Definitions

  • the present invention relates to a plasma processing apparatus that effectively purifies toxic substances (particularly hydrocarbons (HC) that are produced in large quantities) discharged from an internal combustion engine during startup (cold start).
  • toxic substances particularly hydrocarbons (HC) that are produced in large quantities
  • Such a catalytic converter is produced by coating the surface of a partition wall of a honeycomb-structured carrier (honeycomb carrier) with a catalyst layer in which a catalyst (e.g., precious metal) is dispersed in and supported on a heat-resistant inorganic oxide having a large specific surface area (e.g., alumina), the honeycomb-structured carrier including a porous partition wall that is disposed so that a plurality of cells are formed between the end faces of the honeycomb-structured carrier
  • the metal catalyst of the catalytic converter In order to promote purification of exhaust gas, it is necessary to increase the temperature of the metal catalyst of the catalytic converter so that the metal catalyst is activated.
  • the metal catalyst is activated by high-temperature exhaust gas after a given period of time has elapsed after starting an engine.
  • the catalyst is not sufficiently activated immediately after starting an engine due to a low exhaust gas temperature so that toxic substances pass through the catalytic converter without being purified.
  • JP-A-8-218857 discloses an electrical heating-type catalyst that is formed of a honeycomb structure having a circular cross section and provided with exhaust passages and has a slit.
  • the electrical heating-type catalyst disclosed in P-A-8-218857 exhibits an improved exhaust gas purification capability since the temperature distribution of the catalyst carrier can be made uniform.
  • JP-A-2008-45435 discloses an electrical heating-type catalyst apparatus that can efficiently heat the catalyst within a short time without requiring a complex configuration and exhibits an improved exhaust gas purification capability. According to JP-A-2008-45435, power is supplied to the catalyst carrier formed in the shape of a sheet to generate heat so that the exhaust gas purification catalyst is heated.
  • the catalyst apparatus has a narrow portion in which the width in the power supply path direction is partially reduced.
  • JP-A-2005-342714 discloses a catalytic ignition promoter that contains at least one activation metal for reducing the catalytic ignition activation energy.
  • the catalytic ignition promoter is easily prepared from a number of metal supply sources including a spent catalyst and is activated promptly to ensure effective catalytic ignition.
  • JP-T-2007-505265 discloses a method of operating a catalyst for treating exhaust gas from an internal combustion engine, the catalyst including catalytically active precious metals and storage components for storing hydrocarbons.
  • P-A-2007-38121 discloses a gas purification system that effectively decomposes hydrocarbons during startup of an engine by utilizing reactive species generated by plasma without using a catalyst of which the purification function changes depending on the temperature.
  • JP-A-2007-38121 discloses an embodiment in which a discharge reaction section that generates plasma includes a rod-like conductor electrode and a planar common electrode. This makes it possible to initiate a high-energy discharge at a low applied voltage so that gas can be effectively purified at a low temperature at which catalytic activation does not occur.
  • JP-T-2004-160297 discloses an exhaust gas purification apparatus that includes a catalyst that purifies exhaust gas that is discharged from an internal combustion engine and contains NO x and HC, and a plasma generation device that generates plasma. NO contained in exhaust gas is oxidized into active NO 2 by utilizing plasma, and NO 2 is reduced and purified by utilizing the catalyst.
  • JP-A-5-98956 discloses an exhaust gas purification system that includes an exhaust gas purification catalyst, a corona discharge device, and an air supply device provided on the upstream side of the corona discharge device.
  • the exhaust gas purification system disclosed in JP-A-5-98956 causes a corona discharge in a state in which exhaust gas has a high hydrocarbon concentration and the temperature of the catalyst has not reached the activating temperature immediately after starting an engine to obtain a sufficiently high hydrocarbon conversion rate.
  • JP-A-2007-38121 gas is purified by utilizing plasma without using a catalyst.
  • a large amount of power is required since a catalyst is not used.
  • JP-T-2004-160297 and JP-A-5-98956 utilize plasma when the temperature of the catalyst is low.
  • gas is reduced and purified by utilizing the catalyst, the purification efficiency at a low temperature is insufficient, and power is required to generate plasma until the temperature of the catalyst increases. Therefore, power is not efficiently utilized.
  • An object of the present invention is to provide a plasma processing apparatus that utilizes a honeycomb structure and can effectively purify toxic substances (particularly hydrocarbons) discharged from an internal combustion engine during startup.
  • the inventors of the present invention found that heat generated by plasma can be transmitted to an insulator honeycomb to promote a reaction so that a purification target gas can be efficiently purified by disposing an insulator honeycomb, a conductor honeycomb that is disposed to be able to transmit heat to the insulator honeycomb, and a discharge electrode that forms a pair of electrodes with the conductor honeycomb in the inner space of a main body.
  • the following plasma processing apparatus is provided.
  • a plasma processing apparatus comprising a main body that has an inlet for a purification target gas and an outlet for a purified gas, an insulator honeycomb that includes a plurality of cells that are partitioned by a partition wall and serve as gas passages and purifies the purification target gas, a catalyst being supported on the partition wall, a conductor honeycomb that is disposed to be able to transmit heat to the insulator honeycomb and includes a plurality of cells that are partitioned by a partition wall and serve as gas passages, a discharge electrode that is disposed opposite to the conductor honeycomb and forms a pair of electrodes with the conductor honeycomb, and a pulse power supply that applies a pulse voltage between the pair of electrodes to generate plasma between the pair of electrodes, the insulator honeycomb, the conductor honeycomb, and the discharge electrode being disposed in an inner space of the main body.
  • the plasma processing apparatus includes the conductor honeycomb and the discharge electrode that forms a pair of electrodes with the conductor honeycomb, heat generated by plasma that is generated between the pair of electrodes can be transmitted to the insulator honeycomb to promote a reaction so that the purification target gas can be efficiently purified.
  • the conductor honeycomb forms part of the honeycomb structure that purifies the purification target gas
  • the temperature of the conductor honeycomb can be increased by applying a pulse voltage within a short time using only a small amount of power, and the catalyst supported on the insulator honeycomb can be activated by utilizing heat generated by the conductor honeycomb so that purification of the purification target gas can be promoted.
  • the catalyst can be activated within a short time so that exhaust gas can be purified using only a small amount of power. Therefore, toxic substances (particularly hydrocarbons (HC) that are produced in large quantities) discharged from an internal combustion engine during startup (cold start) can be effectively purified.
  • toxic substances particularly hydrocarbons (HC) that are produced in large quantities
  • FIG. 1 is a schematic cross-sectional view showing a plasma processing apparatus (reactor 1 ) according to a first embodiment of the present invention.
  • FIG. 2 is a schematic view showing a power supply line configuration of a plasma processing apparatus (reactor 1 ) according to a first embodiment of the present invention.
  • FIG. 3 is a schematic cross-sectional view showing a plasma processing apparatus (reactor 2 ) according to a second embodiment of the present invention.
  • FIG. 4 is a schematic cross-sectional view showing a plasma processing apparatus (reactor 3 ) according to a third embodiment of the present invention.
  • FIG. 5 is a schematic view showing a power supply line configuration of a plasma processing apparatus (reactor 3 ) according to a third embodiment of the present invention.
  • FIG. 6 is a schematic cross-sectional view showing a plasma processing apparatus (reactor 4 ) according to a fourth embodiment of the present invention.
  • FIG. 7 is a schematic view showing a power supply line configuration of a plasma processing apparatus (reactor 4 ) according to a fourth embodiment of the present invention.
  • FIG. 8 is a schematic view showing a system used to evaluate the performance of a plasma processing apparatus in the examples
  • FIGS. 1 and 2 show a plasma processing apparatus 1 (reactor 1 ) according to a first embodiment of the present invention.
  • FIG. 1 is a schematic cross-sectional view showing the plasma processing apparatus 1 according to the first embodiment.
  • FIG. 2 is a schematic view showing a plasma generation power supply line configuration.
  • the plasma processing apparatus 1 includes a main body 10 that has an inlet for a purification target gas and an outlet for a purified gas, an insulator honeycomb 11 that includes a plurality of cells 3 a that are partitioned by a partition wall 2 a and serve as gas passages, a conductor honeycomb 12 that is disposed to be able to transmit heat to the insulator honeycomb 11 , a discharge electrode 13 that is disposed opposite to the conductor honeycomb 12 and forms a pair of electrodes with the conductor honeycomb 12 , and a pulse power supply 14 that applies a pulse voltage between the pair of electrodes, the insulator honeycomb 11 , the conductor honeycomb 12 , and the discharge electrode 13 being disposed in an inner space of the main body 10 .
  • the main body 10 is a tubular structure in which an inlet for a purification target gas and an outlet for a purified gas are formed. It is necessary for the main body 10 to be hollow so that gas can pass through.
  • the shape of the main body 10 is not particularly limited as long as the main body 10 is hollow.
  • the main body 10 may have a cylindrical shape, a rectangular cylindrical shape, or the like.
  • the maximum inner diameter of the main body 10 is not particularly limited.
  • the size of the main body 10 may be appropriately determined corresponding to the application of the plasma processing apparatus.
  • the material for the main body 10 is not particularly limited. It is preferable to form the housing area of the main body 10 using a metal (e.g., stainless steel) having excellent workability. It is preferable that the electrode installation section and the like inside the housing be formed of an insulating material from the viewpoint of preventing a short circuit.
  • a metal e.g., stainless steel
  • the conductor honeycomb 12 is formed so that a purification target gas (e.g., exhaust gas) can pass through the conductor honeycomb 12 from one end to the other end.
  • the conductor honeycomb 12 is a cylindrical honeycomb structure.
  • the shape of the conductor honeycomb 12 is not limited thereto.
  • the conductor honeycomb 12 may be a honeycomb structure of another shape such as a quadrangular prism.
  • As the material for the conductor honeycomb 12 it is preferable to use a ceramic that exhibits excellent heat resistance taking a usage environment into consideration. It is particularly preferable to use silicon carbide that also exhibits heat transfer properties. Note that the entire conductor honeycomb 12 need not necessarily be formed of silicon carbide.
  • the conductor honeycomb 12 be formed of a conductive ceramic that contains silicon carbide. It is preferable that the conductive ceramic have a volume resistivity of 1—10 ⁇ 2 ⁇ cm to 1 ⁇ 10 6 ⁇ cm and a thermal conductivity at room temperature of 10 to 300 W/mK. Note that the volume resistivity and the thermal conductivity are not limited thereto.
  • the structure of the conductor honeycomb 12 is not particularly limited as long as the conductor honeycomb 12 is a honeycomb structure in which a plurality of cells 3 b that serve as gas passages are partitioned by the partition wall 2 b.
  • the shape of the cells may be appropriately selected from a circle, an ellipse, a triangle, a quadrangle, another polygonal shape, and the like corresponding to the shape of the cells of the insulator honeycomb. It is more preferable that the cells of the conductor honeycomb 12 have the same shape as that of the cells of the insulator honeycomb 11 .
  • the cell density (i.e., the number of cells per unit cross-sectional area) of the conductor honeycomb 12 is not particularly limited, but may be appropriately designed corresponding to the objective. It is preferable that the conductor honeycomb 12 have the same cell density as that of the insulator honeycomb 11 . In this case, it is preferable that the conductor honeycomb 12 have a cell density of 25 to 2000 cells/in 2 (4 to 320 cells/cm 2 ). If the cell density of the conductor honeycomb 12 is less than 25 cells/in 2 , the strength of the partition wall 2 b may decrease so that the strength and the effective geometric surface area (GSA) of the conductor honeycomb 11 may become insufficient. If the cell density of the conductor honeycomb 12 is more than 2000 cells/in 2 , a pressure loss that occurs when exhaust gas flows may increase.
  • the length of the conductor honeycomb 12 is more than 40% of the length of the insulator honeycomb 11 , the volume ratio of the conductor honeycomb 12 to the insulator honeycomb 11 increases so that the exhaust gas purification function of the insulator honeycomb 11 may deteriorate.
  • the conductor honeycomb 12 have an electrical resistance of 2 ⁇ or less, and more preferably 0.3 ⁇ or less at a temperature of 180° C. and an applied voltage of 3.5 V, from the viewpoint of ensuring conductivity.
  • silicon carbide as the conductive ceramic and mix metal silicon with silicon carbide or form a silicon carbide-metal silicon composite, for example.
  • electrical resistance refers to a value determined by measuring the electrical resistance of a rectangular parallelepiped sample (length: 3.3 cm, cross-sectional area: 1.1 cm 2 (cross-sectional area of the cross section perpendicular to the gas flow direction)) obtained by cutting the honeycomb electrode along the gas flow direction (cell formation direction) by a constant-current four-terminal method using a direct-current power supply at a temperature of 180° C. and a voltage terminal distance of 2.3 cm.
  • a metal catalyst supported on the conductor honeycomb 12 includes at least one element selected from the group consisting of a precious metal (i.e., platinum, rhodium, palladium, ruthenium, indium, silver, and gold), aluminum, nickel, zirconium, titanium, cerium, cobalt, manganese, zinc, copper, tin, iron, niobium, magnesium, lanthanum, samarium, bismuth, and barium. These elements may be in the form of an oxide or a compound other than an oxide.
  • a carrier that supports the metal catalyst preferably includes at least one element selected from the group consisting of alumina, ceria, and zirconia.
  • the amount of catalyst (metal catalyst+carrier) supported on the conductor honeycomb 12 is preferably 10 to 400 g/l. When using a precious metal as the metal catalyst, the amount of catalyst supported on the conductor honeycomb 12 is more preferably 0.1 to 5 g/l. If the amount of catalyst (metal catalyst+carrier) supported on the conductor honeycomb 12 is less than 10 g/l, the catalyst may not exhibit a catalytic effect. If the amount of catalyst supported on the conductor honeycomb 12 is more than 400 g/l, a pressure loss and the production cost may increase.
  • the discharge electrode 13 is described below.
  • the discharge electrode 13 is formed as a needle-like electrode.
  • the term “linear electrode” used herein refers to a rod-like electrode. Examples of the linear electrode include a needle-like electrode and the like in addition to a rod-like electrode.
  • the term “rod-like” refers to a linear cylindrical shape of which the outer diameter is uniform along the longitudinal direction.
  • the term “needle-like” refers to a linear shape having a sharp end.
  • the linear electrode is not necessarily limited to a linear shape such as that of a rod-like electrode and a needle-like electrode.
  • the linear electrode may be bent such as in the shape of the letter “L”. It suffices that at least one linear electrode be disposed (i.e., a plurality of linear electrodes may be disposed).
  • the linear electrode be formed of a highly conductive material (e.g., metal, alloy, or conductive ceramic) from the viewpoint of ensuring conductivity.
  • a highly conductive metal include stainless steel, nickel, copper, aluminum, iron, and the like.
  • a highly conductive alloy include an aluminum-copper alloy, a titanium alloy, Inconel (registered trademark), and the like.
  • a conductive ceramic include silicon carbide and the like. Examples of other materials include carbon and the like.
  • the length of the linear electrode is preferably 3 to 50 mm, and more preferably 5 to 30 mm, in order to reduce the size of the plasma processing apparatus 1 . If the length of the linear electrode is less than 3 mm, handling of the linear electrode may become unstable when producing the plasma processing apparatus 1 so that it may be difficult to secure the linear electrode. If the length of the linear electrode is more than 50 mm, the linear electrode may be curved due to contact with the flow of a purification target gas.
  • the outer diameter of the linear electrode is preferably 0.1 to 5 mm, and more preferably 0.5 to 3 mm. If the outer diameter of the linear electrode is less than 0.1 mm, the linear electrode may be curved due to contact with the flow of a purification target gas. As a result, a plasma discharge may become unstable. If the outer diameter of the linear electrode is more than 5 mm, it may be difficult to control a plasma discharge.
  • the linear electrode discharge electrode 13
  • the electrode-to-electrode distance between the linear electrode and the conductor honeycomb 12 is 1 to 30 mm, and more preferably 5 to 10 mm. If the electrode-to-electrode distance is less than 1 mm, a short circuit may easily occur due to electric field concentration. If the electrode-to-electrode distance is more than 30 mm, a plasma discharge may become unstable so that the plasma generation efficiency may decrease.
  • the pulse power supply 14 is described below.
  • the term “pulse power supply” refers to a power supply that applies a pulse voltage between a pair of electrodes.
  • a power supply that can periodically apply a voltage may be used as the pulse power supply 14 . It is preferable to use a power supply that can supply (a) a pulse waveform having a peak voltage of 1 kV or more and a pulse number per second of 1 or more, (b) an AC voltage waveform having a peak voltage of 1 kV or more and a frequency of 1 or more, (c) a DC waveform having a voltage of 1 kV or more, or (d) a voltage waveform formed by superimposing these waveforms.
  • Examples of such a power supply include a high-voltage pulse power supply that utilizes a static induction thyristor (SI thyristor) (manufactured by NGK Insulators, Ltd.) and the like.
  • the insulator honeycomb 11 is described below.
  • the insulator honeycomb 11 has insulating properties and is formed in the shape of a culumn so that gas can pass through the insulator honeycomb 11 from one end to the other end.
  • the insulator honeycomb 11 is a cylindrical honeycomb structure.
  • the insulator honeycomb 11 may be a honeycomb structure of another shape such as a quadrangular prism.
  • the insulator honeycomb main body is formed of an insulating material. It is preferable that the insulator honeycomb main body be formed of a ceramic (insulating ceramic).
  • As the ceramic alumina, zirconia, silicon nitride, aluminum nitride, sialon, mullite, silica, cordierite, or the like may be suitably used. These materials may be used either individually or in combination.
  • a catalyst is supported on the insulator honeycomb 11 .
  • a metal catalyst supported on the insulator honeycomb 11 is not particularly limited as long as exhaust gas can be purified. It is preferable that the metal catalyst include at least one element selected from precious metals such as platinum, rhodium, and palladium. These elements may be in the form of an oxide or a compound other than an oxide.
  • a carrier that supports the metal catalyst preferably includes at least one element selected from the group consisting of alumina, ceria, and zirconia.
  • the amount of catalyst (metal catalyst+carrier) supported on the insulator honeycomb 11 is preferably 10 to 400 g/l. When using a precious metal as the metal catalyst, the amount of catalyst supported on the insulator honeycomb 11 is more preferably 0. 1 to 5 g/l. If the amount of catalyst (metal catalyst+carrier) supported on the insulator honeycomb 11 is less than 10 g/l, the catalyst may not exhibit a catalytic effect. If the amount of catalyst supported on the insulator honeycomb 11 is more than 400 g/l, a pressure loss and the production cost may increase.
  • the discharge electrode 13 , the conductor honeycomb 12 , and the insulator honeycomb 11 are disposed in the inner space of the main body 10 in this order from the inlet side to the outlet side.
  • the discharge electrode 13 is formed as a linear electrode.
  • the linear electrode is disposed opposite to the conductor honeycomb 12 so that plasma is generated between the linear electrode and the conductor honeycomb 12 .
  • the conductor honeycomb 12 is disposed to be able to transmit heat to the insulator honeycomb 11 so that heat generated by the conductor honeycomb 12 is transmitted to the insulator honeycomb 11 and serves as an ignition source for the catalyst supported on the insulator honeycomb 11 .
  • the conductor honeycomb 12 is disposed on the upstream side of the insulator honeycomb 11 at an interval from the insulator honeycomb 11 . Since the conductor honeycomb 12 is disposed at an interval from the insulator honeycomb 11 , active species and the like (that contribute to HC purification) generated by plasma are easily diffused in the insulator honeycomb 11 as compared with a plasma processing apparatus in which the conductor honeycomb 12 is in contact with the insulator honeycomb 11 .
  • activation (ignition) of the catalyst supported on the insulator honeycomb 11 can be promoted using plasma generated by supplying only a small amount of power. Specifically, heat is generated by the conductor honeycomb 12 by generating plasma between the conductor honeycomb 12 and the linear electrode, and is transmitted to the insulator honeycomb 11 to activate the catalyst supported on the insulator honeycomb 11 .
  • a purification target gas exhaust gas
  • the temperature of the catalyst can be increased within a short time using a small amount of power so that exhaust gas can be efficiently purified.
  • activation of the catalyst can be further promoted by utilizing the heat of an exhaust gas purification reaction generated by the conductor honeycomb 11 that supports the catalyst.
  • toxic substances discharged during startup (cold start) of an engine can be purified instantaneously by utilizing the catalyst and plasma generated using a small amount of power.
  • the plasma processing apparatus 1 is particularly effective to purify hydrocarbons (HC) that are produced in large quantities.
  • FIG. 3 shows a plasma processing apparatus 1 (reactor 2 ) according to a second embodiment of the present invention.
  • the conductor honeycomb 12 may be disposed to physically come in contact with the insulator honeycomb 11 .
  • the conductor honeycomb 12 is disposed to come in contact with the purification target gas inlet side of the insulator honeycomb 11 . According to this configuration, heat generated by generating plasma between the linear electrode and the conductor honeycomb 12 can be directly transmitted to the insulator honeycomb 12 and used as an ignition source for the catalyst supported on the insulator honeycomb 11 .
  • FIGS. 4 and 5 show a plasma processing apparatus 1 (reactor 3 ) according to a third embodiment of the present invention.
  • the plasma processing apparatus 1 according to the third embodiment includes a plurality of discharge electrodes 13 and a plurality of pulse power supplies 14 .
  • the plasma generation area is increased by disposing a plurality of discharge electrodes 13 so that gas can be efficiently purified. Therefore, it is preferable to dispose a plurality of discharge electrodes 13 .
  • FIGS. 6 and 7 show a plasma processing apparatus 1 (reactor 4 ) according to a fourth embodiment of the present invention.
  • the conductor honeycomb 12 is disposed to physically come in contact with the insulator honeycomb 11 , as shown in FIGS. 6 and 7 .
  • the conductor honeycomb is embedded in part of the purification target gas inlet side of the insulator honeycomb. According to this configuration, since heat generated by the conductor honeycomb can be easily transmitted to the insulator honeycomb, gas can be purified more efficiently.
  • an increase in temperature of the insulator honeycomb 11 may be insufficient so that the catalytic ignition effect may decrease. If the width of the conductor honeycomb 12 is more than 90% of the width of the insulator honeycomb 11 , the conductor honeycomb 12 that holds the insulator honeycomb 11 may exhibit an insufficient strength.
  • honeycomb structure As a conductor honeycomb, a honeycomb structure which was formed of silicon carbide (content: 75 mass %) and in which a plurality of cells 3 b serving as gas passages were partitioned by a partition wall 2 b was used.
  • the honeycomb structure was obtained by cutting a silicon carbide diesel particulate filter (“SiC-DPF” manufactured by NGK Insulators, Ltd.) for trapping particulate matter contained in engine exhaust gas or the like.
  • two honeycomb structures that differed in size were cut from the diesel particulate filter “SiC-DPF”.
  • One of the two honeycomb structures was a cylindrical honeycomb structure having a square cell shape, a cell density of 96 cells/cm 2 , an outer diameter of 100 mm, and a length (length in the gas flow direction) of 30 mm.
  • the other of the two honeycomb structures was a cylindrical honeycomb structure having a square cell shape, a cell density of 96 cells/cm 2 , an outer diameter of 30 mm, and a length (length in the gas flow direction) of 30 mm.
  • a rectangular parallelepiped sample (length: 3.3 cm, cross-sectional area: 12.3 cm 2 (cross-sectional area of the cross section perpendicular to the gas flow direction)) was obtained by cutting the diesel particulate filter “SiC-DPF” (manufactured by NGK Insulators, Ltd.).
  • the electrical resistance of the sample measured by a constant-current four-terminal method using a direct-current power supply at a temperature of 180° C. and a voltage terminal distance of 2.5 cm was 0.2 ⁇ .
  • the thermal conductivity of the sample measured at 180° C. was 100 W/mK.
  • the thermal conductivity of the sample measured at room temperature was 10 W/mK.
  • a raw material (cordierite) was extruded using a metal die and then fired to obtain an insulator honeycomb.
  • the insulator honeycomb was formed so that the length of the insulator honeycomb in the exhaust gas flow direction was 100 mm, the diameter of the end face was 100 mm, the cell density was 96 cells/cm 2 , and the thickness of the partition wall 2 a was 0.1 mm (dimensions after firing).
  • a catalyst was supported on the insulator honeycomb and the conductor honeycomb as follows.
  • a ⁇ -Al 2 O 3 powder and a CeO 2 powder were mixed in a weight ratio of 70:30. Water and a small amount of nitric acid were added to the mixed powder. The mixture was wet-ground to prepare a carrier slurry.
  • a washcoat layer was formed on each of the conductor honeycomb and the insulator honeycomb by a dipping method using the carrier slurry. The washcoat layer was dried and fired at 500° C. so that each honeycomb was coated with ⁇ -Al 2 O 3 and CeO 2 .
  • the catalyst was supported on the insulator honeycombs of the examples and comparative examples. The presence or absence of catalyst supported on the conductor honeycomb is shown in Table 1.
  • a discharge electrode As a discharge electrode, a rod-like product formed of a nickel alloy (“Inconel 600” manufactured by Nilaco Corporation) and having a length of 10 mm and an outer diameter of 0.5 mm was used.
  • the conductor honeycomb was disposed so that the electrode-to-electrode distance between the conductor honeycomb and the discharge electrode (linear electrode) was 5 mm.
  • the linear electrode was used as a positive electrode.
  • a reactor in which the distance between the conductor honeycomb and the insulator honeycomb was 5 mm was produced (Example 1: see FIG. 1 ).
  • a reactor in which the conductor honeycomb was in contact with the insulator honeycomb was also produced (Examples 2, 3, 5, and 6 and Comparative Example 2: see FIG. 3 for Examples 2 and 5 and Comparative Example 2, and see FIG. 4 for Examples 3 and 6).
  • a reactor in which the conductor honeycomb was embedded in the exhaust gas inlet side of the insulator honeycomb was also produced (Example 4: see FIG. 6 ).
  • a cylindrical body As a main body of the plasma processing apparatus, a cylindrical body (the housing area was made of stainless steel) was used.
  • the linear electrode (discharge electrode), the conductor honeycomb, and the insulator honeycomb were disposed inside the cylindrical body.
  • a pulse power supply As a pulse power supply, a high-voltage pulse power supply that utilizes an SI thyristor (manufactured by NGK Insulators, Ltd.) was used.
  • the pulse power supply was electrically connected to the linear electrode (positive electrode) and the conductor honeycomb (negative electrode). A pulse voltage was applied between the linear electrode and the conductor honeycomb from the pulse power supply in a cycle of 3 kHz.
  • MF test A manifold system (MF) shown in FIG. 8 was formed.
  • the manifold system included an engine 21 , s plasma processing apparatus 1 , a light-off catalyst 22 , and a main catalyst 23 in this order from the upstream side.
  • an L4 engine (displacement: 2000 cc) was used.
  • the Bag emission was measured in accordance with the Federal Test Procedure (FTP) under conditions shown in Table 1 to evaluate the cold start characteristics of the examples and comparative examples.
  • FTP Federal Test Procedure
  • the conductor honeycomb be in contact with the insulator honeycomb in order to effectively activate the catalyst supported on the insulator honeycomb.
  • Example 2 and Example 3 differ in only the number of linear electrodes.
  • the HC emission was reduced in Example 3 as compared with Example 2. This is considered to be because the plasma generation area was increased by disposing a plurality of linear electrodes although the amount of power supplied to one linear electrode decreased. Therefore, it is preferable to dispose a plurality of linear electrodes.
  • Example 2 and Example 4 differ in the installation position of the conductor honeycomb.
  • the HC emission was reduced in Example 4 as compared with Example 2. This is considered to be because heat generated by the conductor honeycomb was easily transmitted to the insulator honeycomb so that activation of the catalyst was further promoted.
  • the present invention is effective to reduce exhaust gas during startup (cold start) of an engine.
  • Example 2 and Comparative Example 2 demonstrate the effect of plasma (catalyst was not used). It is obvious that the HC emission cannot be reduced by merely disposing the conductor honeycomb to come in contact with the insulator honeycomb.
  • the plasma processing apparatus can be used as an exhaust gas purification system that effectively purifies toxic substances (e.g., hydrocarbon (HC), carbon monoxide (CO), and nitrogen oxide (NOx); particularly HC that are produced in large quantities) discharged from an internal combustion engine during startup (cold start).
  • toxic substances e.g., hydrocarbon (HC), carbon monoxide (CO), and nitrogen oxide (NOx); particularly HC that are produced in large quantities

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Analytical Chemistry (AREA)
  • Combustion & Propulsion (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • General Chemical & Material Sciences (AREA)
  • Ceramic Engineering (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Biomedical Technology (AREA)
  • Environmental & Geological Engineering (AREA)
  • Exhaust Gas After Treatment (AREA)
  • Exhaust Gas Treatment By Means Of Catalyst (AREA)
  • Plasma Technology (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)
US12/435,086 2008-05-13 2009-05-04 Plasma processing apparatus Abandoned US20090282817A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2008-126231 2008-05-13
JP2008126231A JP5027732B2 (ja) 2008-05-13 2008-05-13 プラズマ処理装置

Publications (1)

Publication Number Publication Date
US20090282817A1 true US20090282817A1 (en) 2009-11-19

Family

ID=40937549

Family Applications (1)

Application Number Title Priority Date Filing Date
US12/435,086 Abandoned US20090282817A1 (en) 2008-05-13 2009-05-04 Plasma processing apparatus

Country Status (4)

Country Link
US (1) US20090282817A1 (de)
EP (1) EP2120254A3 (de)
JP (1) JP5027732B2 (de)
KR (1) KR20090118824A (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013095796A1 (en) * 2011-12-20 2013-06-27 Caterpillar Inc. Pulsed plasma regeneration of a particulate filter
WO2014054932A2 (ru) * 2012-10-04 2014-04-10 Уаб "Екологиёс Технологию Тиримо Ир Дегимо Институтас" Способ изготовления каталитического сотового элемента с равномерно распределенным по объему плазменным разрядом
US20160040567A1 (en) * 2013-01-28 2016-02-11 Continental Automotive Gmbh Device and method for treating an exhaust gas containing particles
CN111279800A (zh) * 2017-04-20 2020-06-12 埃尔因斯佩斯公司 电晕等离子体设备和等离子体反应器

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6051371B2 (ja) 2011-06-30 2016-12-27 イマジニアリング株式会社 プラズマ生成装置
CN103362602B (zh) * 2012-03-30 2016-01-20 蔡诗敏 汽车尾气净化装置
US20170122269A1 (en) * 2014-10-21 2017-05-04 Eduardo L. COBANKIAT Oxygen excitation system for increasing efficiency and minimizing pollutants of combustion
KR101688611B1 (ko) * 2015-06-15 2016-12-21 한국기계연구원 플라즈마-촉매 방식의 스크러버
CN105771568A (zh) * 2016-03-02 2016-07-20 马骏 一种基于485通讯技术的新型废气处理设备
FR3087677B1 (fr) * 2018-10-25 2022-12-16 Airinspace Nouveau dispositif d’epuration d’air par plasma
US11291102B2 (en) 2017-04-20 2022-03-29 Airinspace S.E. Corona effect plasma device and plasma reactor
EP3849283A1 (de) * 2020-01-09 2021-07-14 terraplasma emission control GmbH Abgasplasmagerät

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4535589A (en) * 1981-05-26 1985-08-20 Nippon Soken, Inc. Exhaust gas cleaning device for internal combustion engine
US6787002B2 (en) * 2000-06-02 2004-09-07 Emitec Gesellschaft Fuer Emissionstechnologie Mbh Compact plasma reactor
US20050063879A1 (en) * 2003-09-24 2005-03-24 Toyota Jidosha Kabushiki Kaisha Exhaust gas purification system
US20050174062A1 (en) * 2004-02-10 2005-08-11 Daikin Industries, Ltd. Plasma reactor and purification equipment
US20050271572A1 (en) * 2004-06-03 2005-12-08 Rohm And Haas Company Activated ignition promoters for metal catalyzed reactions
US20060204409A1 (en) * 1999-05-20 2006-09-14 Institute For Advanced Enginnering Purification system of exhaust gases of an internal combustion engine
US20070166827A1 (en) * 2003-05-16 2007-07-19 Umicore Ag & Co., Kg Method of operating a catalyst which includes components for storing hydrocarbon
US20080072574A1 (en) * 2006-03-30 2008-03-27 Ngk Insulators, Ltd. Plasma reactor
US7946111B2 (en) * 2005-05-18 2011-05-24 Toyota Jidosha Kabushiki Kaisha Apparatus and method for PM purification

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0598956A (ja) 1991-05-24 1993-04-20 Hitachi Ltd 排気浄化システムと浄化方法及びそれを用いた自動車
JPH08218857A (ja) 1995-02-15 1996-08-27 Honda Motor Co Ltd 電気加熱式触媒
US6322757B1 (en) * 1999-08-23 2001-11-27 Massachusetts Institute Of Technology Low power compact plasma fuel converter
JP2004160297A (ja) * 2002-11-11 2004-06-10 Toyota Central Res & Dev Lab Inc ＮＯｘ浄化用プラズマアシスト触媒と排ガス浄化装置及び排ガス浄化方法
JP4329466B2 (ja) * 2003-09-22 2009-09-09 トヨタ自動車株式会社 排気浄化装置
JP2007038121A (ja) 2005-08-02 2007-02-15 Toshiba Corp ガス浄化システムおよびガス浄化方法
JP2007107450A (ja) * 2005-10-13 2007-04-26 Hino Motors Ltd 排気浄化装置
JP2008045435A (ja) 2006-08-11 2008-02-28 Suzuki Motor Corp 電気加熱触媒装置

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4535589A (en) * 1981-05-26 1985-08-20 Nippon Soken, Inc. Exhaust gas cleaning device for internal combustion engine
US20060204409A1 (en) * 1999-05-20 2006-09-14 Institute For Advanced Enginnering Purification system of exhaust gases of an internal combustion engine
US6787002B2 (en) * 2000-06-02 2004-09-07 Emitec Gesellschaft Fuer Emissionstechnologie Mbh Compact plasma reactor
US20070166827A1 (en) * 2003-05-16 2007-07-19 Umicore Ag & Co., Kg Method of operating a catalyst which includes components for storing hydrocarbon
US20050063879A1 (en) * 2003-09-24 2005-03-24 Toyota Jidosha Kabushiki Kaisha Exhaust gas purification system
US20050174062A1 (en) * 2004-02-10 2005-08-11 Daikin Industries, Ltd. Plasma reactor and purification equipment
US20050271572A1 (en) * 2004-06-03 2005-12-08 Rohm And Haas Company Activated ignition promoters for metal catalyzed reactions
US7946111B2 (en) * 2005-05-18 2011-05-24 Toyota Jidosha Kabushiki Kaisha Apparatus and method for PM purification
US20080072574A1 (en) * 2006-03-30 2008-03-27 Ngk Insulators, Ltd. Plasma reactor

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013095796A1 (en) * 2011-12-20 2013-06-27 Caterpillar Inc. Pulsed plasma regeneration of a particulate filter
US8679209B2 (en) 2011-12-20 2014-03-25 Caterpillar Inc. Pulsed plasma regeneration of a particulate filter
WO2014054932A2 (ru) * 2012-10-04 2014-04-10 Уаб "Екологиёс Технологию Тиримо Ир Дегимо Институтас" Способ изготовления каталитического сотового элемента с равномерно распределенным по объему плазменным разрядом
WO2014054932A3 (ru) * 2012-10-04 2015-01-22 Уаб "Екологиёс Технологию Тиримо Ир Дегимо Институтас" Способ изготовления каталитического сотового элемента с равномерно распределенным по объему плазменным разрядом
US20160040567A1 (en) * 2013-01-28 2016-02-11 Continental Automotive Gmbh Device and method for treating an exhaust gas containing particles
US9657617B2 (en) * 2013-01-28 2017-05-23 Continental Automotive Gmbh Device and method for treating an exhaust gas containing particles
CN111279800A (zh) * 2017-04-20 2020-06-12 埃尔因斯佩斯公司 电晕等离子体设备和等离子体反应器

Also Published As

Publication number Publication date
JP2009275555A (ja) 2009-11-26
KR20090118824A (ko) 2009-11-18
JP5027732B2 (ja) 2012-09-19
EP2120254A2 (de) 2009-11-18
EP2120254A3 (de) 2012-04-11

Similar Documents

Publication Publication Date Title
US20090282817A1 (en) Plasma processing apparatus
US4976929A (en) Electrically heated catalytic converter
US5140813A (en) Composite catalytic converter
US7863540B2 (en) Plasma reactor
EP2977096B1 (de) Reduktionsmittelinjektionsvorrichtung, abgasbehandlungsvorrichtung und abgasbehandlungsverfahren
JP4746986B2 (ja) プラズマ発生電極及びプラズマ発生装置、並びに排気ガス浄化装置
EP2272586B1 (de) Plasmareaktor
EP2181755A2 (de) Wabenstruktur und Reaktor, der eine Wabenstruktur einsetzt
EP0661097B1 (de) Honigwabenheizgerät
EP0490222A1 (de) Struktur für einen elektrisch beheizbaren katalytischen Kern
KR20100098505A (ko) 플라즈마 리액터
US7648683B2 (en) Plasma generating electrode, plasma generator, and exhaust gas purifying device
JP3210508B2 (ja) ハニカムヒーター
US20230374925A1 (en) Heating carrier, and exhaust gas reduction carrier having heating carrier
JPH0666132A (ja) ハニカムヒーター
EP2196258A1 (de) Reaktor
US8263011B2 (en) Reactor
JP2004245096A (ja) プラズマリアクタ
US20100247402A1 (en) Reactor
EP0661421B1 (de) Honigwabenheizgerät
JPH115021A (ja) 排ガス浄化システム
JPH06296873A (ja) ハニカムヒータおよびこれを用いた排気ガス浄化装置
JP2001252573A (ja) ハニカムヒーター

Legal Events

Date Code Title Description
AS Assignment

Owner name: NGK INSULATORS, LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:MASUDA, MASAAKI;MIYAIRI, YUKIO;TAKAHASHI, MICHIO;REEL/FRAME:022638/0772

Effective date: 20090417

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION