CA1083485A - Device for the purification of exhaust gases - Google Patents
Device for the purification of exhaust gasesInfo
- Publication number
- CA1083485A CA1083485A CA293,859A CA293859A CA1083485A CA 1083485 A CA1083485 A CA 1083485A CA 293859 A CA293859 A CA 293859A CA 1083485 A CA1083485 A CA 1083485A
- Authority
- CA
- Canada
- Prior art keywords
- pipe
- metal
- exhaust gases
- exhaust
- catalyst
- 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.)
- Expired
Links
Classifications
-
- 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
- B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
- B01D53/9445—Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC]
- B01D53/9454—Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC] characterised by a specific device
-
- 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
-
- 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
- F01N2510/00—Surface coverings
- F01N2510/06—Surface coverings for exhaust purification, e.g. catalytic reaction
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B1/00—Engines characterised by fuel-air mixture compression
- F02B1/02—Engines characterised by fuel-air mixture compression with positive ignition
- F02B1/04—Engines characterised by fuel-air mixture compression with positive ignition with fuel-air mixture admission into cylinder
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Abstract
ABSTRACT OF THE DISCLOSURE
The present invention relates to a device comprising a standard automobile exhaust pipe in the form of a metal tube which is so equipped to produce a specific back pressure namely; 0.3 to 2500 mm water column, as measured at an air velocity of 12 meters per second at room temperature. The tube is completely or partial-ly lined with a catalyst composition, for example a composition which will convert hydrocarbons and the carbon monoxide content of exhaust gases into water and carbondioxide, and further, convert nitrogen oxides to nitrogen. The significant advantage of the present invention is that it permits the dimensions of standard automobile exhaust pipes to be retained and does not require the expensive construction of a special canister for containing a monolithic or pelletized catalyst which has become a common fea-ture in automobile muffler systems in recent years.
The present invention relates to a device comprising a standard automobile exhaust pipe in the form of a metal tube which is so equipped to produce a specific back pressure namely; 0.3 to 2500 mm water column, as measured at an air velocity of 12 meters per second at room temperature. The tube is completely or partial-ly lined with a catalyst composition, for example a composition which will convert hydrocarbons and the carbon monoxide content of exhaust gases into water and carbondioxide, and further, convert nitrogen oxides to nitrogen. The significant advantage of the present invention is that it permits the dimensions of standard automobile exhaust pipes to be retained and does not require the expensive construction of a special canister for containing a monolithic or pelletized catalyst which has become a common fea-ture in automobile muffler systems in recent years.
Description
33~a~5 : ~
The deleterious substances of waste gases, particul- -arly of exhaust gases from internal combustion engines of motor vehicles constitute a danger to human health. In a number of countries they have been limited by fixing the maximim concentration of deleterious substances in exhaust gases from motor cars by law. Thus, for example, in the U.S.
and in ~apan the corresponding limiting values are so low that they can be maintained to a great extent only by catalytic purification.
It is the aim of the invention to create a very simple device by means of which the deleterious substances in the exhaust gases from internal combustion engines can be -reacted to a great extent. :
For the purification of exhaust gases from motor cars it is known to use catalyst mounted on ceramic support material. The use of ceramic supports has the disadvantage that they are sensitive to mechanical stresses and that they must be installed in the exhaust tail pipe by means of an additional mounting support.
Like a thermoreactor the supported catalysts and their mounting supports require, for their mounting, additional space in the vehicle near the engine. Since usually very little space is avaiable under the motor hood or under the chassis of the vehicle, any device reducing the space require-ments is of advantage.
Catalysts in which the catalytically active substance is coated on a metallic support have been described. For ;
example, the laid-open German Specification 22 51631 describes a process for the purification of waste gases on a metallic support of an electrically conductive material which is coated with a catalyst.
According to the laid-open Çerman Specifications .. .
..... . ...... . . . ~ ~ ~
'.
.
23 51 237 and 23 04 351 a cat~l~tically active material is coated on to a metallic support, which can be an imitation of a ceramic monolithic support. The geometric sur~ace required for this support is as large as that proposed accord-ing to the laid-open German Specification 24 50 664.
In the laid-open German Specification 23 13 040 the requirement of a small pressure loss due to the catalyst is pointed out. However, the catalyst described therein requires substantial amounts of metal resistant to high temperature and corrosion.
Similarly to the Gould catalyst for the reduction of nitric oxide which consists of nickel/copper alloy, in the catalyst of the laid-open German Specification 24 53 358 tHe support itself is catalytically active. However, the small specific surface which presents no ideal prerequisites for the catalytic reaction of the gas molecules on the active metal is a disadvantage of this catalyst type, which is also des-cribed in the laid-open German Specification 21 64 123.
Quite generally, the catalysts known at present are eXpensive and, in particular, they require a substantial amount of space. Therefore, it is the aim of the invention to overcome these disadvantages.
The subject matter of the invention is a device for the catalytic purification of exhaust gases, particularly of those from internal combustion engines of motor vehicles.
Accordingly, the present invention provides a device for a catalytic purification of exhaust gases, particularly from internal combustion engine of motor vehicles, comprising a metal tube or system of metal tubes which is so designed or ~itted that in use, it interferes with, and/or changes the direction of the flow of exhaust gases and which compared with a corresponding tube or system of tubes designed or fitted ~ ~V8;~41~5 in such a way that it does not interfere with the flow and/or does not change the direction of the flow, produces a pressure head increase of ~.3 to 2500 mm of water, measured at a velocity of air flow of 12 metres per second, and at room temperature, the metal tube being completely or partially lined with catalyst material.
In agreement with the exhaust pipe present in all motor vehicles the invention assigns a further function at least to a section thereof in that it designs the exhaust pipe in the latter's section near the engine as a catalytic con- -verter. For this purpose the device is mounted between the exhaust gas outlet of the engine and, for example, the muffler so that because of the hot combustion gases emerging directly from the engine the time of heating up the catalyst is short.
The flow interfering design or equipment and the lining with catalytically active layers are important features of the invention, The converter tube, which is resistant to high temperature and insensitive to corrosion, renders the exhaust gas flow turbulent by diverting and turning it and intensifies the turbulence. Surprisingly enough, it has been found that even a slight interference with the flow, which is evident ~;
from the increased pressure head, results in an unexpectedly high improvement of the conversion. This interference with the flow can be attained by baffles suitably installed in the metal tube.
The metal tube can have various shapes. Its cross-sectional shape can correspond to that of the exhaust pipe.
Circularity or a oval cross section are preferably chosen.
When designing the dimensions of the metal tube of the device the fact that at the high flow velocities encountered aperture cross sections which are too small offer undesirably high .,. ... ~
'.
~ 348S
resistances to the flow of the exhaust gas. Aperture cross sections which are too large are disadvantageous for reasons of space requirements. The metal tube can be installed immediately behind the engine outlet valve in order to }~ ~e the high exhaust gas temperatures behind said valve for the ~~ conversion of the deleterious substances.
A substantial advantage of the exhaust-gas-purifying device according to the invention over waste gas converters operating with loose material or monolithic catalysts lies in that the dimensions of conventional exhaust pipes of motor vehicles can be substantially retained.
The metal tube usually has an aperture which corres-ponds to a circular surface having a diameter of 8 to 250 mm.
The tube length can be between 80 and 3500 mm. In many cases it can be advantageous to replace the entire exhaust pipe by a device according to the invention of the same length.
Corresponding to the chemical and thermal stresses encountered the material of the metal tube consists of corrosion-resistant and high-temperature-resistant metal, as ~ a tr~/e~r-tJ ~ a~Je ~r~) for example, Thermax, Kanthal~ non-alloyed steel, etc. In this case the requirements of materal are substantially lower than in known exhuast-gas-purifiying devices.
The metal tube can be rendered flow-interfering by curving the tube axis. However, the required resistance to flow can also be obtained by a rough, fissured or angularly projecting design of the inside tube wall. Thus, for example, it may be sufficient to provide a cylindrical metal tube with ' grooves at intervals so that projecting edges are obtained in the wall, ~oreover, the metal tube, i.e., only in the gas-~nlet region, can be provided with baffles in the form of singly- or doubly coiled spiral threads, by means of which the exhaust-gas flow obtains an additional rotation about its .~
own axis.
,.,~. , ~:.: , ' . . . , , ,: ' .
According to a development of the device the metal tube is provided with flow-interfering baffles such as deflecting surfaces (blades), These baffles made of plate, perforated plate, metal net or ceramics are so shaped and arranged that the pressure head according to the invention is maintained. The device is preferably so designed that it produces an increase of the pressure head of 1 to 500 mm water column at an air speed of 12 metres per second and at room temperature as compared with a tube having, for example, a smooth inside wall. Laminar or spherically curved flow -~
disturbers can be arranged in labyrinth fashion in order to satisfy these conditions.
The flow-interfering baffles can be rigidly or detachably secured to the inside surface of the metal tube.
In a favourable modification of the manner of mounting, the -~
., : .
baffles are secured to strips arranged in the metal tube. The ~ -strips are in turn mounted detachably to one or several points in the tube~ Of course various kinds of flow-interfering members can be used in one and the same device in order to produce the desired control of the flow.
Moreover, the device according to the invention can be so designed that the construction or equipment which inter-feres with the flow and/or changes its direction is provided only in the inlet region of the exhaust gas into the metal tube or system of metal tubes. In this case the rear section of the metal tube is so designed that it does not interfere with the flow and/or does not change its direction.
However, according to a preferred modifiaation it is possible to arrange a catalyst-free, flow-interfering and/or flow~direction-changing construction or equipment of the metal tube or system of metal tubes in the direction of exhaust gas flow ahead of the flow section lined with catalyst material.
. ., - .- . , . , , , . ,. . , . . :
, . ,, ,. .. . .. , , . ", . ,.... , ", ... , , , . , ., , ,; ,, '' ' . ' ' ' ' : ' ''. ", ., . ' : ' ,: :., , '.. . : ' ' ' ':
~0~3485 However, the rear flow section lined entirely or partially with catalyst material need not be so designed that it interferes with the flow and/or changes its direction.
Einally, within the scope o~ the invention it is possible that the exhaust manifold of the internal combustion engine or the exhaust head (muffler) of the motor vehicle is so designed that it interferes with the flow and/or changes its direction.
Since the baffles are usually exposed to higher thermal stresses than the metal tube, at least the same type of material is used for the baffles as for the metal tube, or ceramics resistant to high temperatures, such as sintered corundum, silicon carbide or reaction-sintered silicon nitride.
However, tube and baffles do not have to consist of the same material.
The catalyst material may be coated on the inner surfaces of the metal tube or on the baffles or on both.
The catalyst material preferably contains at least one base-metallic oxide having a specific surface larger than 1 sq m per gram. Oxides of the elements of the second to fourth principal group of the periodic system as well as oxides of secondary,group elements having melting points above 1000C
are suitable base-metallic oxides. The use of mixed oxides is also possible.
Examples are ~-aluminium oxide, zirconium oxide, titanium dioxide, magnesium oxide, silicon dioxide, zinc oxide, chromium oxide, nickel oxide, manganese oxide, copper-chromium oxide, oxides of the rare earths such as cerium oxide as well as combinations of said oxides. However, these base-metallic oxides or mixed oxides can also be applied as a coating on a ~-catalytically inactive ceramic coating, the latter coating adhering to the metal surface of the converter tube. Examples - 6 ~
. . ., ,: .
--' ~ol33485 of these inert coatings are ~aluminium oxide, mullite or cordierite.
Catalyst systems containing base metal or noble metal are used as the catalytically active component. They are deposited either on the inert ceramics or on a combination of ceramic support and a base-metallic-oxide coating. Noble metals such as the metals of the platinum group are preferably used either individually or in mixture. This group includes particularly platinum, palladium, rhodium, iridium and ; ~
ruthenium but moxe specifically platinum, palladium and -rhodium. The noble metals are used in amounts from 20 to 5000 mg per litre.
The coating process can be carried out in ~arious ways:
1) The catalyst can be coated directly on the metal tube by applying it from a liquid, particularly aqueous phase or from the gas phase.
The deleterious substances of waste gases, particul- -arly of exhaust gases from internal combustion engines of motor vehicles constitute a danger to human health. In a number of countries they have been limited by fixing the maximim concentration of deleterious substances in exhaust gases from motor cars by law. Thus, for example, in the U.S.
and in ~apan the corresponding limiting values are so low that they can be maintained to a great extent only by catalytic purification.
It is the aim of the invention to create a very simple device by means of which the deleterious substances in the exhaust gases from internal combustion engines can be -reacted to a great extent. :
For the purification of exhaust gases from motor cars it is known to use catalyst mounted on ceramic support material. The use of ceramic supports has the disadvantage that they are sensitive to mechanical stresses and that they must be installed in the exhaust tail pipe by means of an additional mounting support.
Like a thermoreactor the supported catalysts and their mounting supports require, for their mounting, additional space in the vehicle near the engine. Since usually very little space is avaiable under the motor hood or under the chassis of the vehicle, any device reducing the space require-ments is of advantage.
Catalysts in which the catalytically active substance is coated on a metallic support have been described. For ;
example, the laid-open German Specification 22 51631 describes a process for the purification of waste gases on a metallic support of an electrically conductive material which is coated with a catalyst.
According to the laid-open Çerman Specifications .. .
..... . ...... . . . ~ ~ ~
'.
.
23 51 237 and 23 04 351 a cat~l~tically active material is coated on to a metallic support, which can be an imitation of a ceramic monolithic support. The geometric sur~ace required for this support is as large as that proposed accord-ing to the laid-open German Specification 24 50 664.
In the laid-open German Specification 23 13 040 the requirement of a small pressure loss due to the catalyst is pointed out. However, the catalyst described therein requires substantial amounts of metal resistant to high temperature and corrosion.
Similarly to the Gould catalyst for the reduction of nitric oxide which consists of nickel/copper alloy, in the catalyst of the laid-open German Specification 24 53 358 tHe support itself is catalytically active. However, the small specific surface which presents no ideal prerequisites for the catalytic reaction of the gas molecules on the active metal is a disadvantage of this catalyst type, which is also des-cribed in the laid-open German Specification 21 64 123.
Quite generally, the catalysts known at present are eXpensive and, in particular, they require a substantial amount of space. Therefore, it is the aim of the invention to overcome these disadvantages.
The subject matter of the invention is a device for the catalytic purification of exhaust gases, particularly of those from internal combustion engines of motor vehicles.
Accordingly, the present invention provides a device for a catalytic purification of exhaust gases, particularly from internal combustion engine of motor vehicles, comprising a metal tube or system of metal tubes which is so designed or ~itted that in use, it interferes with, and/or changes the direction of the flow of exhaust gases and which compared with a corresponding tube or system of tubes designed or fitted ~ ~V8;~41~5 in such a way that it does not interfere with the flow and/or does not change the direction of the flow, produces a pressure head increase of ~.3 to 2500 mm of water, measured at a velocity of air flow of 12 metres per second, and at room temperature, the metal tube being completely or partially lined with catalyst material.
In agreement with the exhaust pipe present in all motor vehicles the invention assigns a further function at least to a section thereof in that it designs the exhaust pipe in the latter's section near the engine as a catalytic con- -verter. For this purpose the device is mounted between the exhaust gas outlet of the engine and, for example, the muffler so that because of the hot combustion gases emerging directly from the engine the time of heating up the catalyst is short.
The flow interfering design or equipment and the lining with catalytically active layers are important features of the invention, The converter tube, which is resistant to high temperature and insensitive to corrosion, renders the exhaust gas flow turbulent by diverting and turning it and intensifies the turbulence. Surprisingly enough, it has been found that even a slight interference with the flow, which is evident ~;
from the increased pressure head, results in an unexpectedly high improvement of the conversion. This interference with the flow can be attained by baffles suitably installed in the metal tube.
The metal tube can have various shapes. Its cross-sectional shape can correspond to that of the exhaust pipe.
Circularity or a oval cross section are preferably chosen.
When designing the dimensions of the metal tube of the device the fact that at the high flow velocities encountered aperture cross sections which are too small offer undesirably high .,. ... ~
'.
~ 348S
resistances to the flow of the exhaust gas. Aperture cross sections which are too large are disadvantageous for reasons of space requirements. The metal tube can be installed immediately behind the engine outlet valve in order to }~ ~e the high exhaust gas temperatures behind said valve for the ~~ conversion of the deleterious substances.
A substantial advantage of the exhaust-gas-purifying device according to the invention over waste gas converters operating with loose material or monolithic catalysts lies in that the dimensions of conventional exhaust pipes of motor vehicles can be substantially retained.
The metal tube usually has an aperture which corres-ponds to a circular surface having a diameter of 8 to 250 mm.
The tube length can be between 80 and 3500 mm. In many cases it can be advantageous to replace the entire exhaust pipe by a device according to the invention of the same length.
Corresponding to the chemical and thermal stresses encountered the material of the metal tube consists of corrosion-resistant and high-temperature-resistant metal, as ~ a tr~/e~r-tJ ~ a~Je ~r~) for example, Thermax, Kanthal~ non-alloyed steel, etc. In this case the requirements of materal are substantially lower than in known exhuast-gas-purifiying devices.
The metal tube can be rendered flow-interfering by curving the tube axis. However, the required resistance to flow can also be obtained by a rough, fissured or angularly projecting design of the inside tube wall. Thus, for example, it may be sufficient to provide a cylindrical metal tube with ' grooves at intervals so that projecting edges are obtained in the wall, ~oreover, the metal tube, i.e., only in the gas-~nlet region, can be provided with baffles in the form of singly- or doubly coiled spiral threads, by means of which the exhaust-gas flow obtains an additional rotation about its .~
own axis.
,.,~. , ~:.: , ' . . . , , ,: ' .
According to a development of the device the metal tube is provided with flow-interfering baffles such as deflecting surfaces (blades), These baffles made of plate, perforated plate, metal net or ceramics are so shaped and arranged that the pressure head according to the invention is maintained. The device is preferably so designed that it produces an increase of the pressure head of 1 to 500 mm water column at an air speed of 12 metres per second and at room temperature as compared with a tube having, for example, a smooth inside wall. Laminar or spherically curved flow -~
disturbers can be arranged in labyrinth fashion in order to satisfy these conditions.
The flow-interfering baffles can be rigidly or detachably secured to the inside surface of the metal tube.
In a favourable modification of the manner of mounting, the -~
., : .
baffles are secured to strips arranged in the metal tube. The ~ -strips are in turn mounted detachably to one or several points in the tube~ Of course various kinds of flow-interfering members can be used in one and the same device in order to produce the desired control of the flow.
Moreover, the device according to the invention can be so designed that the construction or equipment which inter-feres with the flow and/or changes its direction is provided only in the inlet region of the exhaust gas into the metal tube or system of metal tubes. In this case the rear section of the metal tube is so designed that it does not interfere with the flow and/or does not change its direction.
However, according to a preferred modifiaation it is possible to arrange a catalyst-free, flow-interfering and/or flow~direction-changing construction or equipment of the metal tube or system of metal tubes in the direction of exhaust gas flow ahead of the flow section lined with catalyst material.
. ., - .- . , . , , , . ,. . , . . :
, . ,, ,. .. . .. , , . ", . ,.... , ", ... , , , . , ., , ,; ,, '' ' . ' ' ' ' : ' ''. ", ., . ' : ' ,: :., , '.. . : ' ' ' ':
~0~3485 However, the rear flow section lined entirely or partially with catalyst material need not be so designed that it interferes with the flow and/or changes its direction.
Einally, within the scope o~ the invention it is possible that the exhaust manifold of the internal combustion engine or the exhaust head (muffler) of the motor vehicle is so designed that it interferes with the flow and/or changes its direction.
Since the baffles are usually exposed to higher thermal stresses than the metal tube, at least the same type of material is used for the baffles as for the metal tube, or ceramics resistant to high temperatures, such as sintered corundum, silicon carbide or reaction-sintered silicon nitride.
However, tube and baffles do not have to consist of the same material.
The catalyst material may be coated on the inner surfaces of the metal tube or on the baffles or on both.
The catalyst material preferably contains at least one base-metallic oxide having a specific surface larger than 1 sq m per gram. Oxides of the elements of the second to fourth principal group of the periodic system as well as oxides of secondary,group elements having melting points above 1000C
are suitable base-metallic oxides. The use of mixed oxides is also possible.
Examples are ~-aluminium oxide, zirconium oxide, titanium dioxide, magnesium oxide, silicon dioxide, zinc oxide, chromium oxide, nickel oxide, manganese oxide, copper-chromium oxide, oxides of the rare earths such as cerium oxide as well as combinations of said oxides. However, these base-metallic oxides or mixed oxides can also be applied as a coating on a ~-catalytically inactive ceramic coating, the latter coating adhering to the metal surface of the converter tube. Examples - 6 ~
. . ., ,: .
--' ~ol33485 of these inert coatings are ~aluminium oxide, mullite or cordierite.
Catalyst systems containing base metal or noble metal are used as the catalytically active component. They are deposited either on the inert ceramics or on a combination of ceramic support and a base-metallic-oxide coating. Noble metals such as the metals of the platinum group are preferably used either individually or in mixture. This group includes particularly platinum, palladium, rhodium, iridium and ; ~
ruthenium but moxe specifically platinum, palladium and -rhodium. The noble metals are used in amounts from 20 to 5000 mg per litre.
The coating process can be carried out in ~arious ways:
1) The catalyst can be coated directly on the metal tube by applying it from a liquid, particularly aqueous phase or from the gas phase.
2) However, it is also possible to coat the metal tube first with a film of a highly superficial material, which can then be coated or impre-gnated with-the catalytically active material.
In this case, too, the steps of the process can differ. A material having a high specific surface can be precipitated from a salt solution or from a dispersion. The layer can be obtained by a chemical precipitaiion on the tube or, for example, by flame-spraying. In the latter case ~ -the material can be applied directly in the form in which it is used later, for example, as an oxide, or first in the elementary form, from which it is then converted into the final form -by additional treatment. This after-treatment :. . :
. . .
':
: . . .: . :, . . .
, ~
can be, for example, an oxidation with oxygen or with oxidizing agents contained in liquids. The catalyst can then be coated on this layer in the manner described hereinbefore.
In this case, too, the steps of the process can differ. A material having a high specific surface can be precipitated from a salt solution or from a dispersion. The layer can be obtained by a chemical precipitaiion on the tube or, for example, by flame-spraying. In the latter case ~ -the material can be applied directly in the form in which it is used later, for example, as an oxide, or first in the elementary form, from which it is then converted into the final form -by additional treatment. This after-treatment :. . :
. . .
':
: . . .: . :, . . .
, ~
can be, for example, an oxidation with oxygen or with oxidizing agents contained in liquids. The catalyst can then be coated on this layer in the manner described hereinbefore.
3) In some modes of application it is expedient to coat the metal coat first with a rigidly adhering layer of an inert material of ~-A1203, cordierite, mullite or the like. The catalyst can then be applied directly to this layer or after the coating with the intermediate layer described hereinbefore.
It is also possible to apply the metal of the intermediate layer jointly with the catalyst material in one step.
As mentioned hereinbefore, fundamentally it is always possible to deposit the material on the inside wall of the tube by two methods. The material can be adhesively applied from the gas phase by vapour deposition or from the liquid phase by separation. The latter method comprises the operation with molten material, for example, flame-spraying, dipping into the melt as well as working with solutions, dispersions, suspensions, which contain water or other inorganic or organic solvents as the liquid medium.
Irrespective of the coating method a preliminary treatment of the converter tube is carried out in most cases in .
prder to purify and/or roughen the metal surface. This can be done by brushing, sand blasting or grinding. If required, the baffles are included. In cases in which only the baffles are to be coated with catalyst solution they are first subject~
ed to surface treatment and then coated before being installed in the converter tube.
The coating from a liquid medium can be carried out from a solution or a dispersion or a suspension o~ the catalyst . .
, 8 -~L019348S
, material. It can be carried out in one stage or in several process steps. As mentioned hereinbe~ore, a melt-coating operation can be carried out by flame spraying or also by dipping the parts to be coated into molten catalyst material.
Catalyst materials in which the catalytically active metallic oxides or metals are coated on an intermediate layer of alkaline-earth-metal and/or earth-metal and/or rare-earth oxide, particularly of aluminium and/or titanium and/or zirconium oxide were found to be particularly effective and to have creep rupture strength. As mentioned hereinbefore, the intermediate layer can also be coated on a ceramic lining of the metal tube.
The conversion effects attainable with the devicè
according to the invention are unexpectedly high despite the simple construction. Thus, from the exhaust gas of an Otto carburetor engine having a metal tube provided with baffles (baffles and tube coated with catalyst material) said metal tube having only one tenth of the geometric surface of a conventional ceramic monolythic catalyst coated with the same catalyst material, 80% of the hydrocarbons and 60% of the carbon monoxide were reacted. As compared therewith 80% of the hydrocarbons and 95% of carbon monoxide were converted in the of the monolithic catalyst, The invention also covers the use of the device for the purification of the exhaust gases from internal combustion engines, particularly for the oxidation of hydrocarbons and carbon monoxide as well as for the reduction of nitric Qxides, which are contained as deleterious substances in the exhaust ~ ~
gases of Otto carburetor engines. Diesel engines and internal -combustion engines with revolving pistons.
The invention will now be described in more detail by way of example only, with reference to the drawings, in -- which;-~ g _ .
, ,: ~ :, :- . . . .
.' . ' ~ ' : , : ,. . .
-` ~L083~S
Figure 1 shows various embodiments in the direction of the tube axis for a circular tube diameter For oval, elliptic, rectangular, quadratlc or similarly shaped cross-sections the Figures 1 and 2 apply correspondingly.
The Figures lA, D, E, F, G, H and I show baffles having various shapes which reduce the free cross section of the tube. The remaining free cross section can be varied according to requirements by correspondingly increasing or decreasing the shapes shown in the Figures.
As is evident from said Figures the reduction can be obtained by means of a plate as shown in Figure lB, with perforated plate or, as shown in Figure lC, with a gauge wire!,.
However, a metal strip (Fig. lI), which is helically coiled or provided with additional, turbulence-producing surfaces (Fig, 2C) is also suitable. The strip can also be twisted and provided with additional surfaces.
However~ the interfering surfaces can also be installed.alternatingly in the tube (Fig. 2A, 2B). Figure 3 shows the embodiments 2C, 2D and 2A in perspective represent-ation, Example 1 ~ .
A tube having a length of 110 cm, an inside diameter of 45 mm and a wall thickness of 1.5 mm was provided with 10 diaphragms of the kind shown in Figure lA and 2A. The diaphragms covered 40% of the circular surface in each case and were rotated alternatingly by 180~ about the tube axis.
They ~ere installed at intervals of approximately 10 cm. The resistance to flow at an air speed of 12 metres per second ;~
and at room temperature was 400 mm water column compared with a corresponding tube haviny a smooth inside wall. This tube was freed from coarse impurities by slight sand-blasting and provided with a thin layer of ~A1203 by flame-spraying. Said ,, . : ' ~ -, . . ' . , ,. , , : ., ~. .. .
~as3~s layer was reinforced by a subsequently applied layer of ~-A1203 (specific surface of the solid 130 sq m per gram) -from an aqueous dispersion. ThiS layer was impregnated with an aqueous solution containing of 1 g of noble metal in a ratio of 8,5 parts of platinum to 1 part of rhodium.
Example 2 The tube described in example 1 was acted upon with 110 cu m of engine exhaust gas per hour. This exhaust gas contained 0.5% of CO, 0.02% of NO2, 0.015~ of hydrocarbons, 1.2% of 2 as well as 13.8% of CO2, approximately 10% of H2O
and a rest of nitrogen.
At 700C a conversion of 64% of hydrocarbons and 35.3~ of CO was obtained.
Example 3 (Comparison Example) A tube like that described in example 1 but without baffles (diaphragm) is-coated in the same manner as in example 1. This tube is tested corresponding to the conditions described in example 2. The resulting conversion is slight, i.e., 17.6~ of hydrocarbons and 20.0% of CO.
Example 4 A tube made of heat-resistant steel alloy Thermax and having an inside diameter of 40 mm and a length of 950 mm~`
is coated on the inside wall with 1 g of platinum and l g of A12O3 (specific surface 150 sq m per gram~ by precipitation with ammonia. Four perforated plates having boreholes of 2 mm `~ (remaining area 80%) are so installed at regular intervals of 200 mm (see Fig. lA, 2B) that as compared with the free tube an increase of the resistance to flow of 3 mm water column at an air speed of 12 metres per second is obtained.
Exa_ple 5 (Comparison Example) A tube like that in example 4 is produced but with-,.,~ , . .
out installing the four perforated plates.
- 11 - " ' ' ' ' ~ . . .
: ' . , : : ' 1~)83485 , Example 6 A tube like that in example 4 is produced. Four perforated plates are extending into the inside space of the tube to such an-extent that as compared with the tube if example 5, an increase of the resistance to flow of 110 mm water column at an air speed of 12 metres per second is obtained.
Example 7 The tubes produced according to the examples 4 to 6 are tested in a synthesis-gas testing apparatus. 24000 litres of air per hour are preheated to the measuring temperature whereupon 0.5~ by volume of CO and 200 p.p.m. of propene are added. The conversion is determined at intervals of 10C.
The following values for the temperature of the 50~ CO
reaction rate are obtained:
tube according to example 4 : 410~C
tube according to example 5 : 550~C
tube according to example 6 : 350~C
This example shows that, as compared with the free ~ -tube, the increase of the resistance to flow required to reduce the starting temperature by 140~C and thus to improve substantially the rate of reaction is surprisingly low.
. ~ ,.
.
';
' ' ''
It is also possible to apply the metal of the intermediate layer jointly with the catalyst material in one step.
As mentioned hereinbefore, fundamentally it is always possible to deposit the material on the inside wall of the tube by two methods. The material can be adhesively applied from the gas phase by vapour deposition or from the liquid phase by separation. The latter method comprises the operation with molten material, for example, flame-spraying, dipping into the melt as well as working with solutions, dispersions, suspensions, which contain water or other inorganic or organic solvents as the liquid medium.
Irrespective of the coating method a preliminary treatment of the converter tube is carried out in most cases in .
prder to purify and/or roughen the metal surface. This can be done by brushing, sand blasting or grinding. If required, the baffles are included. In cases in which only the baffles are to be coated with catalyst solution they are first subject~
ed to surface treatment and then coated before being installed in the converter tube.
The coating from a liquid medium can be carried out from a solution or a dispersion or a suspension o~ the catalyst . .
, 8 -~L019348S
, material. It can be carried out in one stage or in several process steps. As mentioned hereinbe~ore, a melt-coating operation can be carried out by flame spraying or also by dipping the parts to be coated into molten catalyst material.
Catalyst materials in which the catalytically active metallic oxides or metals are coated on an intermediate layer of alkaline-earth-metal and/or earth-metal and/or rare-earth oxide, particularly of aluminium and/or titanium and/or zirconium oxide were found to be particularly effective and to have creep rupture strength. As mentioned hereinbefore, the intermediate layer can also be coated on a ceramic lining of the metal tube.
The conversion effects attainable with the devicè
according to the invention are unexpectedly high despite the simple construction. Thus, from the exhaust gas of an Otto carburetor engine having a metal tube provided with baffles (baffles and tube coated with catalyst material) said metal tube having only one tenth of the geometric surface of a conventional ceramic monolythic catalyst coated with the same catalyst material, 80% of the hydrocarbons and 60% of the carbon monoxide were reacted. As compared therewith 80% of the hydrocarbons and 95% of carbon monoxide were converted in the of the monolithic catalyst, The invention also covers the use of the device for the purification of the exhaust gases from internal combustion engines, particularly for the oxidation of hydrocarbons and carbon monoxide as well as for the reduction of nitric Qxides, which are contained as deleterious substances in the exhaust ~ ~
gases of Otto carburetor engines. Diesel engines and internal -combustion engines with revolving pistons.
The invention will now be described in more detail by way of example only, with reference to the drawings, in -- which;-~ g _ .
, ,: ~ :, :- . . . .
.' . ' ~ ' : , : ,. . .
-` ~L083~S
Figure 1 shows various embodiments in the direction of the tube axis for a circular tube diameter For oval, elliptic, rectangular, quadratlc or similarly shaped cross-sections the Figures 1 and 2 apply correspondingly.
The Figures lA, D, E, F, G, H and I show baffles having various shapes which reduce the free cross section of the tube. The remaining free cross section can be varied according to requirements by correspondingly increasing or decreasing the shapes shown in the Figures.
As is evident from said Figures the reduction can be obtained by means of a plate as shown in Figure lB, with perforated plate or, as shown in Figure lC, with a gauge wire!,.
However, a metal strip (Fig. lI), which is helically coiled or provided with additional, turbulence-producing surfaces (Fig, 2C) is also suitable. The strip can also be twisted and provided with additional surfaces.
However~ the interfering surfaces can also be installed.alternatingly in the tube (Fig. 2A, 2B). Figure 3 shows the embodiments 2C, 2D and 2A in perspective represent-ation, Example 1 ~ .
A tube having a length of 110 cm, an inside diameter of 45 mm and a wall thickness of 1.5 mm was provided with 10 diaphragms of the kind shown in Figure lA and 2A. The diaphragms covered 40% of the circular surface in each case and were rotated alternatingly by 180~ about the tube axis.
They ~ere installed at intervals of approximately 10 cm. The resistance to flow at an air speed of 12 metres per second ;~
and at room temperature was 400 mm water column compared with a corresponding tube haviny a smooth inside wall. This tube was freed from coarse impurities by slight sand-blasting and provided with a thin layer of ~A1203 by flame-spraying. Said ,, . : ' ~ -, . . ' . , ,. , , : ., ~. .. .
~as3~s layer was reinforced by a subsequently applied layer of ~-A1203 (specific surface of the solid 130 sq m per gram) -from an aqueous dispersion. ThiS layer was impregnated with an aqueous solution containing of 1 g of noble metal in a ratio of 8,5 parts of platinum to 1 part of rhodium.
Example 2 The tube described in example 1 was acted upon with 110 cu m of engine exhaust gas per hour. This exhaust gas contained 0.5% of CO, 0.02% of NO2, 0.015~ of hydrocarbons, 1.2% of 2 as well as 13.8% of CO2, approximately 10% of H2O
and a rest of nitrogen.
At 700C a conversion of 64% of hydrocarbons and 35.3~ of CO was obtained.
Example 3 (Comparison Example) A tube like that described in example 1 but without baffles (diaphragm) is-coated in the same manner as in example 1. This tube is tested corresponding to the conditions described in example 2. The resulting conversion is slight, i.e., 17.6~ of hydrocarbons and 20.0% of CO.
Example 4 A tube made of heat-resistant steel alloy Thermax and having an inside diameter of 40 mm and a length of 950 mm~`
is coated on the inside wall with 1 g of platinum and l g of A12O3 (specific surface 150 sq m per gram~ by precipitation with ammonia. Four perforated plates having boreholes of 2 mm `~ (remaining area 80%) are so installed at regular intervals of 200 mm (see Fig. lA, 2B) that as compared with the free tube an increase of the resistance to flow of 3 mm water column at an air speed of 12 metres per second is obtained.
Exa_ple 5 (Comparison Example) A tube like that in example 4 is produced but with-,.,~ , . .
out installing the four perforated plates.
- 11 - " ' ' ' ' ~ . . .
: ' . , : : ' 1~)83485 , Example 6 A tube like that in example 4 is produced. Four perforated plates are extending into the inside space of the tube to such an-extent that as compared with the tube if example 5, an increase of the resistance to flow of 110 mm water column at an air speed of 12 metres per second is obtained.
Example 7 The tubes produced according to the examples 4 to 6 are tested in a synthesis-gas testing apparatus. 24000 litres of air per hour are preheated to the measuring temperature whereupon 0.5~ by volume of CO and 200 p.p.m. of propene are added. The conversion is determined at intervals of 10C.
The following values for the temperature of the 50~ CO
reaction rate are obtained:
tube according to example 4 : 410~C
tube according to example 5 : 550~C
tube according to example 6 : 350~C
This example shows that, as compared with the free ~ -tube, the increase of the resistance to flow required to reduce the starting temperature by 140~C and thus to improve substantially the rate of reaction is surprisingly low.
. ~ ,.
.
';
' ' ''
Claims (10)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Apparatus for the catalytic purification of exhaust gases from the combustion engines of motor vehicles comprising a metal automobile exhaust pipe provided with high temperature resistant means in the form of baffle surfaces positioned in said pipe in such a way so as to impart at least one of a flow disturb-ing and flow direction changing motion to exhaust gases when passing through said pipe and wherein said means increases the dynamic pressure inside said pipe by 1.0 to 500 mm of water measured at a flow velocity of air at room temperature of 12 meters/second and lowers the temperature for achieving 50% CO
conversion, as compared to a pipe not equipped with said means, the interior of said pipe being at least partially coated with a catalyst component and being mounted between the exhaust outlet of the engine and the muffler and wherein said exhaust gases pass through said pipe as the sole means for subjecting the exhaust gases to catalytic action to convert the hydrocarbons and CO content of said exhaust gas into H2O and CO2 and nitrogen oxides to nitrogen.
conversion, as compared to a pipe not equipped with said means, the interior of said pipe being at least partially coated with a catalyst component and being mounted between the exhaust outlet of the engine and the muffler and wherein said exhaust gases pass through said pipe as the sole means for subjecting the exhaust gases to catalytic action to convert the hydrocarbons and CO content of said exhaust gas into H2O and CO2 and nitrogen oxides to nitrogen.
2. An apparatus as defined in claim 1 wherein the metal pipe has an opening, the cross section of which corresponds to a circular cross-sectional surface area with a diameter of 8 to 250 mm and a length of 80 to 3500 mm.
3. An apparatus as defined in claim 1 wherein the metal pipe consists of corrosion resistant or temperature resistant metal.
4. An apparatus as defined in claim 1 wherein said baffle means are attached on strips disposed in the metal pipe.
5. An apparatus as defined in claim 1 wherein the catalyst material has a specific surface larger than 1 m2/g.
6. An apparatus as defined in claim 1, wherein oxides of the elements of the second to the fourth main group of the periodic system as well as oxides of the subgroup elements with a melting point above 1000°C are used in the catalyst composition.
7. An apparatus as defined in claim 6, wherein the platinum group metals are used in the catalyst.
8. An apparatus as defined in claim 7, wherein the platinum group metals are used in a quantity of 20 to 5000 mg/1 volume of metal pipe.
9. An apparatus as defined in claim 5, wherein catalytically active metal oxides or metals are applied on an intermediate layer selected from the group consisting of aluminium oxide, zirconium oxide, titanium dioxide, magnesium oxide, silicon dioxide, zinc oxide, chromium oxide, nickel oxide, manganese oxide, copper chromium oxide and rare earth oxides and mixtures thereof.
10. A process for the catalytic purification of exhaust gases from combustion engines of motor vehicles, comprising passing the exhaust gases from a motor vehicle through at least one metal exhaust pipe provided with high temperature resistant means in the form of baffle surfaces positioned in said pipe to impart at least one of a flow disturbing and flow direction changing motion to said exhaust gases when said gases pass through said pipe and wherein said means increases the dynamic pressure inside said pipe by 1.0 to 500 mm of water, measured at a flow velocity of air at room temperature of 12 meters/second, and lowers the temperature for achieving 50% CO conversion as compared to a pipe not equipped with said means, at least a portion of the interior surfaces in said pipe being coated with a catalyst component, said pipe being mounted between the exhaust outset of the engine and the muffler wherein the exhaust gases are subjected to catalytic action to convert the hydrocarbons and CO
content of said exhaust gas into H2O and/or reducing nitrogen oxides to nitrogen.
content of said exhaust gas into H2O and/or reducing nitrogen oxides to nitrogen.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP2658892.1 | 1976-12-24 | ||
| DE19762658892 DE2658892A1 (en) | 1976-12-24 | 1976-12-24 | DEVICE FOR CATALYTIC CLEANING OF EXHAUST GASES |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1083485A true CA1083485A (en) | 1980-08-12 |
Family
ID=5996669
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA293,859A Expired CA1083485A (en) | 1976-12-24 | 1977-12-23 | Device for the purification of exhaust gases |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US4318894A (en) |
| JP (1) | JPS53114773A (en) |
| CA (1) | CA1083485A (en) |
| DE (1) | DE2658892A1 (en) |
| FR (1) | FR2375449A1 (en) |
| GB (1) | GB1564560A (en) |
| PL (1) | PL117819B1 (en) |
| SE (1) | SE7714751L (en) |
Families Citing this family (45)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4442024A (en) * | 1982-02-09 | 1984-04-10 | Texaco Inc. | Catalyst and method of making the same |
| IT1182270B (en) * | 1984-09-18 | 1987-10-05 | Luigi Carboni | SILENCER SYSTEM FOR EXHAUST GAS OF TERNA COMBUSTION ENGINES |
| JPH0667454B2 (en) * | 1985-09-30 | 1994-08-31 | 三菱重工業株式会社 | Comprehensive exhaust gas treatment method |
| DE3735033A1 (en) * | 1987-10-16 | 1989-04-27 | Duerrwaechter E Dr Doduco | CATALYST AND METHOD FOR THE PRODUCTION THEREOF |
| AT396170B (en) * | 1989-06-01 | 1993-06-25 | Laimboeck Franz | EXHAUST SYSTEM FOR TWO-STROKE COMBUSTION ENGINES |
| US4985388A (en) * | 1989-06-29 | 1991-01-15 | W. R. Grace & Co.-Conn. | Catalytic exhaust pipe insert |
| US5589144A (en) * | 1990-05-01 | 1996-12-31 | Filippi; John E. | Thermal barrier for an exhaust system |
| JP2952997B2 (en) * | 1990-08-27 | 1999-09-27 | スズキ株式会社 | Exhaust gas purification device |
| US5358698A (en) * | 1991-02-26 | 1994-10-25 | Fina Technology, Inc. | Apparatus for dehydrogenation of ethylbenzene to styrene |
| DE4142505C2 (en) * | 1991-12-21 | 1994-12-08 | Draegerwerk Ag | Chemical oxygen generator with reaction controls |
| DE4142504C1 (en) * | 1991-12-21 | 1993-03-18 | Draegerwerk Ag, 2400 Luebeck, De | |
| US5639429A (en) * | 1992-02-24 | 1997-06-17 | Consejo Superior Investigaciones Cientificas | Reactor for the production of short ceramic fibers from gas |
| IT1273749B (en) * | 1993-04-02 | 1997-07-10 | Gutehoffnungshuette Man | DEVICE FOR THE PURIFICATION OF HEAVY METALS AND SLOTS OF SYNTHESIS GAS GENERATED FROM REFINERY WASTE |
| US5492678A (en) * | 1993-07-23 | 1996-02-20 | Hokushin Industries, Inc. | Gas-cleaning equipment and its use |
| US5425924A (en) * | 1993-09-07 | 1995-06-20 | Finley; Charles M. | Compact fixed-bed reactor with folded reaction path |
| US5512250A (en) * | 1994-03-02 | 1996-04-30 | Catalytica, Inc. | Catalyst structure employing integral heat exchange |
| US5427746A (en) * | 1994-03-08 | 1995-06-27 | W. R. Grace & Co.-Conn. | Flow modification devices for reducing emissions from thermal voc oxidizers |
| WO1996020783A1 (en) * | 1995-01-04 | 1996-07-11 | Fujitsu Limited | Gas reactor |
| JP2849987B2 (en) * | 1995-03-24 | 1999-01-27 | 本田技研工業株式会社 | Exhaust gas purification device |
| US6422008B2 (en) | 1996-04-19 | 2002-07-23 | Engelhard Corporation | System for reduction of harmful exhaust emissions from diesel engines |
| US5987882A (en) * | 1996-04-19 | 1999-11-23 | Engelhard Corporation | System for reduction of harmful exhaust emissions from diesel engines |
| US6013513A (en) * | 1997-10-30 | 2000-01-11 | Motorola, Inc. | Molecular detection apparatus |
| FR2772829B1 (en) * | 1997-12-24 | 2000-03-03 | Valeo Thermique Moteur Sa | CATALYTIC CONTAINER WITH TEMPERATURE MANAGEMENT, ESPECIALLY FOR A MOTOR VEHICLE |
| US20050163677A1 (en) * | 1998-05-01 | 2005-07-28 | Engelhard Corporation | Catalyst members having electric arc sprayed substrates and methods of making the same |
| US20010027165A1 (en) * | 1998-05-01 | 2001-10-04 | Michael P. Galligan | Catalyst members having electric arc sprayed substrates and methods of making the same |
| US20020128151A1 (en) * | 1998-05-01 | 2002-09-12 | Michael P. Galligan | Catalyst members having electric arc sprayed substrates and methods of making the same |
| US8062990B2 (en) * | 1998-05-01 | 2011-11-22 | Basf Corporation | Metal catalyst carriers and catalyst members made therefrom |
| US6762335B1 (en) * | 2000-02-29 | 2004-07-13 | Fina Technology, Inc. | Apparatus for dehydrogenation of ethylbenzene to styrene |
| WO2001094010A2 (en) * | 2000-06-02 | 2001-12-13 | Engelhard Corporation | Pliable metal catalyst carriers, conformable catalyst members made therefrom and methods of installing the same |
| US6655369B2 (en) * | 2001-08-01 | 2003-12-02 | Diesel Engine Transformations Llc | Catalytic combustion surfaces and method for creating catalytic combustion surfaces |
| US7566487B2 (en) * | 2004-07-07 | 2009-07-28 | Jonathan Jay Feinstein | Reactor with primary and secondary channels |
| US8394469B2 (en) * | 2004-07-14 | 2013-03-12 | Yamaha Hatsudoki Kabushiki Kaisha | Exhaust pipe for internal combustion engine |
| US20070015002A1 (en) * | 2005-07-14 | 2007-01-18 | Ut-Battele, Llc | Oxygen-donor and catalytic coatings of metal oxides and metals |
| US20080286177A1 (en) * | 2007-05-18 | 2008-11-20 | Tribute Creations, Llc | Reactor with differentially distributed catalytic activity |
| US7887764B2 (en) * | 2007-09-18 | 2011-02-15 | Jernberg Gary R | Mixer with a catalytic surface |
| US20090098289A1 (en) * | 2007-10-12 | 2009-04-16 | Deininger Mark A | Pig and Method for Applying Prophylactic Surface Treatments |
| US8776499B2 (en) * | 2008-02-25 | 2014-07-15 | Basf Corporation | Emission treatment systems and methods using passivated surfaces |
| US8623301B1 (en) | 2008-04-09 | 2014-01-07 | C3 International, Llc | Solid oxide fuel cells, electrolyzers, and sensors, and methods of making and using the same |
| CA2789281C (en) | 2010-02-10 | 2015-11-24 | C3 International, Llc | Low temperature electrolytes for solid oxide cells having high ionic conductivity |
| DE102012008108A1 (en) * | 2012-04-25 | 2013-10-31 | Umicore Ag & Co. Kg | Static gas mixer |
| JP2014018766A (en) * | 2012-07-20 | 2014-02-03 | Hitachi Aic Inc | Catalytic reaction modular |
| WO2015009618A1 (en) | 2013-07-15 | 2015-01-22 | Fcet, Llc | Low temperature solid oxide cells |
| US11541412B2 (en) * | 2015-12-23 | 2023-01-03 | Commonwealth Scientific And Industrial Research Organisation | Static mixers for continuous flow catalytic reactors |
| GB2570834B (en) * | 2016-11-30 | 2021-11-10 | Cummins Emission Solutions Inc | Temperature estimation for sensor |
| CN107261834A (en) * | 2017-07-14 | 2017-10-20 | 北京大爱乾坤环卫设备有限公司 | Photocatalytic air handles pipeline |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA730675A (en) * | 1966-03-22 | Texaco Development Corporation | Catalyst for exhaust system, method of making same, and process for effecting oxidation | |
| GB354692A (en) * | 1929-05-07 | 1931-08-13 | Ladislas Sobanski | Improvements relating to the purification of the exhaust gases of internal combustion engines |
| BE497441A (en) * | 1949-08-09 | |||
| US2679724A (en) * | 1950-01-16 | 1954-06-01 | Edmund S Pomykala | Exhaust gas purifier |
| US3554929A (en) * | 1967-06-08 | 1971-01-12 | Du Pont | High surface area alumina coatings on catalyst supports |
| US3917811A (en) * | 1970-10-19 | 1975-11-04 | Kenics Corp | Interactive surface mixer |
| US3716344A (en) * | 1971-02-10 | 1973-02-13 | New Prod Corp | Internal combustion engine exhaust catalytic reactor |
| US3996443A (en) * | 1975-04-23 | 1976-12-07 | Klaus Keller | Apparatus for the manufacture of reinforcement trusses |
| JPS51124727A (en) * | 1975-04-24 | 1976-10-30 | Harunobu Miura | The apparatus for treating the catalysts for car exhaust gas |
-
1976
- 1976-12-24 DE DE19762658892 patent/DE2658892A1/en not_active Withdrawn
-
1977
- 1977-11-07 FR FR7733456A patent/FR2375449A1/en active Granted
- 1977-12-01 PL PL1977202570A patent/PL117819B1/en unknown
- 1977-12-22 GB GB53424/77A patent/GB1564560A/en not_active Expired
- 1977-12-23 CA CA293,859A patent/CA1083485A/en not_active Expired
- 1977-12-23 SE SE7714751A patent/SE7714751L/en not_active Application Discontinuation
- 1977-12-24 JP JP15632477A patent/JPS53114773A/en active Pending
-
1980
- 1980-12-29 US US06/220,569 patent/US4318894A/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| FR2375449A1 (en) | 1978-07-21 |
| GB1564560A (en) | 1980-04-10 |
| PL202570A1 (en) | 1978-07-03 |
| US4318894A (en) | 1982-03-09 |
| SE7714751L (en) | 1978-06-25 |
| PL117819B1 (en) | 1981-08-31 |
| FR2375449B1 (en) | 1982-04-16 |
| DE2658892A1 (en) | 1978-07-06 |
| JPS53114773A (en) | 1978-10-06 |
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| MKEX | Expiry |