Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS3473323 A
Publication typeGrant
Publication dateOct 21, 1969
Filing dateJul 11, 1968
Priority dateJul 11, 1968
Publication numberUS 3473323 A, US 3473323A, US-A-3473323, US3473323 A, US3473323A
InventorsSouthwick W Briggs, Howard W Gilbert
Original AssigneeSouthwick W Briggs, Howard W Gilbert
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Oxidation apparatus
US 3473323 A
Abstract  available in
Images(3)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

Oct. 21, 1969 g ET AL 3,473,323

OXIDATION APPARATUS Filed July 11, 1968 3 Sheets-Sheet 1 FIG. 3

INVENTORS SOUTHWICK W. BRIGGS HOWARD W. GILBERT A TORNEYS Oct. 21, 1969 s. w. BRIGGS ET 3,473,323

OXIDATION APPARATUS Filed July 11, 1968 I5 Sheets-Sheet z FIG. 5

[.NVENTORS SOUTHWICK W. BRIGGS HOWARD W. GlLBERT BY @m, Mam,

ATTORNEYS Oct. 21, 1969 5, amass ET AL 3,473,323

OXIDATION APPARATUS Filed July 11, 1968 3 Sheets-Sheet 3 III/IIIIAIWIIIIIIIII L 142 I38 |50 40 44 FIG. 8

INVENTORS SOUTHWICK w. BRIGGS HOWARD W. GILBERT ATTO NEYS United States Patent 3,473,323 OXIDATION APPARATUS Southwick W. Briggs, 6420 Western Ave., and Howard W. Gilbert, 6818 Brookville Road, both of Chevy Chase, Md. 20015 Continuation-impart of applications Ser. No. 438,660, Mar. 10, 1965, and Ser. No. 540,412, Apr. 5, 1966. This application July 11, 1968, Ser. No. 744,191

Int. Cl. F01n 3/14; B01j 9/04 US. CI. 60-30 18 Claims ABSTRACT OF THE DISCLOSURE There is provided an oxidizer :for the exhaust gases of an internal combustion engine designed to burn off incompletely consumed combustible components of the exhaust gases. A combustion chamber maintained at combustion temperature is provided in the exhaust system. The inner surface of the combustion chamber is reflective to thermal radiations thereby to maintain the required high temperature in the combustion chamber. An oxidizing agent such as atmospheric air is drawn into the exhaust system to support combustion. The combustion chamber may include ignition means such as jagged edges of tapered metal tongues to prevent blow-out of the combustible material.

The present application is a continuation-in-part of application Ser. No. 438,660, filed Mar. 10, 196-5 and application Ser. No. 540,412, filed Apr. 5, 1966, both now abandoned.

This invention relates to oxidation apparatus for the combustion of unburned components remaining in exhaust gases of internal combustion engines.

There has been appreciable activity directed to the prevention of smog produced by the exhaust gases of internal combustion engines during the past several years. Considerable legislation has been passed and appreciably more is under consideration, requiring that automotive vehicles be equipped with devices for the elimination of unburned components from the exhaust gases. Various arrangements have been proposed for the solution of the problems involved, but because of high costs in some cases and inadequate operation in others, the problems have not been solved thus far.

It is an object of the present invention therefore to provide a new and improved apparatus for burning unburned components remaining in exhaust gases of internal combustion engines.

Another object of thepresent invention is the provision of new and improved exhaust apparatus for internal combustion engines.

Further objects and advantages of the present invention will become apparent as the following description proceeds and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

The apparatus contemplated by the present invention comprises a conduit having an inlet for exhaust gases, means for introducing an oxidizing fluid into the conduit for admixture with the gases, a container defining a hollow combustion chamber connected to the conduit, the chamber having an internal wall surface resistant to high temperature gases and highly reflective to radiations in the infrared or heat range, defined as having wavelengths from 0.6 to 10.0 microns, and a discharge tube communicating with the chamber. The exhaust gases may pass in direct contact with the internal wall surface of the combustion chamber to be heated by thermal radiation therefrom.

Patented Oct. 21, 1969 It has been found that the radiant energy emission spectrum from burning fuels has very little radiation beyond 10 microns and that the visible radiation, below 0.6 micron, is not present in amounts to be worth reflecting. Thus, the radiation wavelength in the infrared range of 0.6 to 10.0 micron wavelength represents the practical region for reflective efforts.

Any reflective surface in the combustion chamber may be used which has 'suflicient reflection in the 0.6 to 10.0 micron range and which will not deteriorate at the temperatures and atmosphere conditions to which it is exposed. Generally, an oxide layer on the surface creates a loss of snificient thermal reflection so that the device is rendered inoperative. Gold has been found to satisfy the requirements for a surface coating. The extremely high thermal reflectance of gold in the infrared region of 0.6 to 10.0 microns provides a very effective combustor. Moreover, gold resists the formation of oxides and the build-up of carbon coatings so that its efficiency remains unimpaired over a long period of operation.

Stainless steel and iron, commonly used in engine exhause systems and mufllers, proved unsatisfactory as thermal reflectors. Although they worked fairly well at first, they ceased to operate when darkened by oxidation causing loss in thermal reflectivity. Silver, platinum, chromium and nickel were also found unsatisfactory and inoperative. Aluminum would not stand up to the 1600 to 1800 F. temperatures encountered in the combustion chambers.

In one embodiment the inlet conduit extends into the combustion chamber and has a plurality of perforations which may be defined by jagged edges in the form of tapered metal tongues extending towards the reflective surface, the aggregate area of the perforations being at least as great as the cross sectional area of the conduit.

In another embodiment the conduit is in the form of a nozzle having a reduced throat acting as a venturi, and the conduit downstream of the throat defines the combustion chamber. If desired, an igniter can be disposed in the combustion chamber, which may be in the form of metal filamentary material.

The internal surface of the hollow combustion chamber is coated with a suitable temperature resistant and thermally reflective material such as gold, and the external surface may be similarly coated to define reflective surfaces having the required characteristics of reflectivity of radiations within the necessary range resistance to attack by the gases encountered, and retentivity of the reflective properties. The gold coating applied to the container may be superimposed upon a layer of nickel, in accordance with known practice, to avoid diffusion of the gold into the sheet metal from which the container is likely to be formed.

A more complete understanding of the invention will follow from a description of the accompanying drawings wherein:

FIG. 1 is a somewhat diagrammatic elevation depicting the apparatus of the present invention, partially in section;

FIG. 2 is a fragmentary sectional elevation on an enlarged scale depicting the gold coated chamberwall and taken along line 2-2 of FIG. 1;

FIG. 3 is an elevation depicting a connection between the engine crankcase and apparatus of the type shown in FIG. 1;

FIG. 4 is a somewhat diagrammatic elevaiton according to another embodiment of the present invention illustrating conduits having perforations with sharp, jagged points;

FIG. 5 is a fragmentary elevation, partially in section, depicting the perforated structure of the conduits;

FIG. 6 is a somewhat schematic side view depicting another embodiment of the apparatus of the invention interposed between an exhaust manifold of an engine and a muffler;

FIG. 7 is a sectional elevation illustrating the embodiment of the invention illustrated in FIG. 6;

FIG. 8 is a sectional elevation depicting yet another embodiment of the invention;

FIG. 9 is a section taken along line 9-9 of FIG. 7;

FIG. 10 is a section taken along line 10--10 of FIG. 7; and

FIG. 11 is a section taken along line 11-11 of FIG. 7.

Referring now to the drawings, and particularly to the embodiment of FIGS. 1 and 2, there is illustrated an internal combustion engine 8 having an exhaust manifold 10 joined by a coupling 12 to a conduit 14 provided with an inlet fitting 16 adjacent the exhaust manifold for the introduction of air or other oxidizing medium through an inlet pipe 18 to support combustion of any components remaining in the exhaust gases which are susceptible to oxidation. The discharge end 20 of the conduit 14 is received within a container 22 defining a hollow combustion chamber and which is in turn enclosed within a housing 24 having an axial wall or walls 26 and end walls 28. A discharge tube or tail pipe 30 has an inlet end 32 disposed within the container 22 and its discharge end 34 in communication with atmosphere. The housing 24 is assembled by means of welded joints 36 to provide a fluid tight enclosure for the container 22 and the ends of the conduit 14 and discharge tube 30.

The ends of the conduit 14 and discharge tube 30 are closed by means of plates 38 in order that the exhaust gases undergoing treatment will flow through perforations or openings 40 formed in the portions of the conduit and discharge tube within the container 22 and adjacent their ends. A section of the wall of the container 22 has been depicted in FIG. 2 wherein a sheet metal wall 44, which may be sheet steel, is plated on its opposite surfaces with a layer of nickel 46, over which layers of gold 48 are deposited. As will be evident from FIG. 1, all of the walls of the container 22 are similarly gold plated to assure the maximum retention of heat within the container. These gold coated reflective surfaces also serve to reflect thermal radiations produced by virtue of the chemical reactions occuring during combustion. Gold is used as the reflecting material because it provides the' characteristics primarily required for effective operation of the apparatus. It is resistant to heat and heat shock, retains its thermal reflective properties, is resistant to corrosion, particularly at the temperature range of 1600 F. to 1800" F. required for combustion and is effective as a thermal reflector in the infrared wavelength rang of 0.6 to 10.0 microns, the most critical portion of that range lying between 2.0 and 6.0 microns. The thickness of the gold plating must be suflicient to assure maximum thermal reflectivity. Accordingly, a minimum thickness of the order of 0.0003 inch is preferred. A suitable minimum thickness for the nickel coating beneath the gold will be of the order of about 0.007 inch.

The combustion air inlet 18 is preferably located adjacent the exhaust manifold 10 to reduce heat loss and enhance mixing of the air with the gases. The combustion air can be introduced by a blower or by a venturi action, or otherwise as may be desired.

The apparatus of FIGS. 1 and 2 is shown in FIG. 3 with the addition of a tubular connection 50 between the crankcase of the internal combustion engine 8 and a tube 54 through which the air or other oxidation supporting fluid is introduced into the inlet pipe 18 so as to induce the flow of the vapors from the crankcase. The tube 54 is preferably formed of material having a low heat conductivity to preclude combustion of the crankcase vapors prior to their entry into the container 22. By directing these crankcase vapors into the container 22, the combustion of the oxidizable components of the exhaust gases will be facilitated and the difficulties, such as sticking valves, attending the introduction of these vapors through the carburetor, will be avoided.

FIGS. 4 and 5 illustrate an embodiment of the invention wherein ignition of the unburned materials is aided by hot projections into the combustion chamber. Similar parts of the embodiment of FIGS. 4 and 5 and of the embodiment of FIGS. 1 to 3 are identified by the same reference numerals. As therein illustrated, the internal combustion engine exhaust manifold 10 is joined by a coupling 12 to a conduit 14 provided with an inlet fitting 16 adjacent the exhaust manifold for the introduction of air through an inlet pipe 18 to support combustion of any components remaining in the exhaust gases which are susceptible to oxidation. The discharge end 20 of the conduit 14 is received within a container 22 which is in turn enclosed within a housing 24 having an axial wall or walls 26 and end walls 28. A discharge tube or tail pipe 30 has an inlet end 32 disposed Within the container 22 and its discharge end 34 in communication with atmosphere. The housing 24 is assembled by means of welded joints 36 to provide a fluid tight enclosure for the container 22 and the ends of the conduit 14 and discharge tube 30.

The ends of the conduit 14 and discharge tube 30 are closed by means of plates 38 in order that the exhaust gases undergoing treatment will flow through perforations 41 formed in the portions of the conduit and discharge tube within the container 22 and adjacent their ends. The conduit 14 and discharge tube 30 are composed of a relatively low thermal conductivity alloy such as 347 stainless steel and the perforations are defined by jagged edges in the form of tapered metal tongues, resembling a structure commonly found in food graters. The configuration producing these perforations is illustrated in FIG. 5 wherein the tapered metal tongues 42 produce the jagged edges and tend to concentrate the heat at a plurality of points within the container to assure ignition of the components of the exhaust gases to be oxidized. Preferably, the aggregate area of the perforations is at least as great as the cross sectional area of the conduit carrying the exhaust gases.

Inasmuch as the discharge from an internal combustion engine occurs in the form of pulses, it is believed that the shock waves produced by such a system contribute to the heating effects at the jagged edges defining the perforations 41 to effect the desired combustion of the exhaust gas components susceptible to oxidation. The resemblance of the construction of the present apparatus to mufiiers of the types used for automotive engines will be recognized immediately by those skilled in the art. And, as a matter of fact, the apparatus constituting the present invention will function as a mufiler as well as serving to effect combustion of the oxidizable exhaust gas components.

If desired, the jagged edge perforations may be used in connection with a gold coated combustion chamber, as illustrated in FIG. 4, thus improving the operation of the oxidation apparatus. However, it is understood that under certain conditions, the hot jagged edges of the perforations 41 may be suflicient by themselves to maintain ignition of the unburned components of the exhaust gases.

Referring now to the embodiment of FIGS. 6 and 7, there is illustrated the internal combustion engine 8, somewhat diagrammatically represented in FIG. 6, with the exhaust manifold 10 whose flange 12 is bolted to a flange 116 provided on a conduit 118 having an upstream portion 120, a venturi or throat portion 122 and a downstream portion 124, the downstream portion having a discharge end 126 suitably coupled to the upstream end of a mufller 128 from which exhaust gases are discharged through a port 130.

The throat portion of the conduit 118 is defined by a convergent-divergent surface 132 formed on a sleeve 134 received within a coupling member 136 provided with flanges 138 and 140 coupled with the flanges 142 and l44 of the upstream portion and the downstream portion 124 respectively.

A port 146 formed in the sleeve 134 communicates with the throat 148 and with a source of oxidizer, which will in most cases be atmospheric air, through a tube 150. The air or other oxidizer may be fed solely by the aspiration produced by the reduced pressure formed at the throat 148, and/or, a suitable pump, not shown, may be used to increase the flow of air or other oxidizer.

Starting at the throat 148, there is defined a hollow combustion chamber 151, the internal surface of which is rendered resistant to high temperature gases and highly reflective to thermal radiations within the infrared range of 0.6 to 10.0 microns in a downstream direction and the downstream portion of the conduit 124 is provided with a similar internal surface, as a result of which, heat losses are reduced appreciably and combustion of any unburned components of the exhaust gases will be substantially assured. The temperature resistant and highly reflective surfaces are preferably defined by the application of gold 152 by means of known coating or plating techniques that will assure proper adherence at the temperatures encountered in operation. The exhaust gases are in direct contact with the coated surface 152 of the combustion chamber 151 and are heated in part by thermal reflection from the surface of the combustion chamber resulting from the burning of unburned components of the exhaust gases within the combustion chamber.

In the form of the invention depicted in FIG. 7, an igniter 154 is introduced into the downstream portion 124 of the conduit 118 so as to become heated by the burning gases and to maintain an ignition temperature for reignition wherever there has been an interruption in burning due to a change of load or any other cause. The igniter is shown as assuming the form of metal filamentary material such as stainless steel bristles suitably secured together and to the conduit itself.

The divergent portion of the throat has been found to produce highly satisfactory results where its length is of the order of five times the diameter of the throat itself, and similarly, the downstream portion of the conduit extending beyond the throat and provided with the highly reflective surface has been found to produce highly satisfactory results where its length is of the order of thirteen times the diameter of the throat.

The apparatus of FIG. 8 differs from that of FIGS. 6 and 7 primarily in the use of a flexible metal hose 156 as the downstream portion of the conduit, adapting this portion to assume a configuration that will be dictated by the structure of the vehicle to which the apparatus is applied. The downstream portion of the conduit may be suitably enclosed to reduce the loss of heat through radiation.

Where a flexible metal hose is employed as depicted in FIG. 8, it has been found to be preferable that as much of the internal surface as possible lie in the surface of a cylinder so as to increase the reflectivity and thereby reduce the loss of heat.

Although the present invention has been described by reference to several embodiments thereof, it will be apparent that numerous other modifications and embodiments will be devised by those skilled in the art which will fall within the true spirit and scope of the present invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. Internal combustion engine exhaust gas oxidation apparatus comprising a conduit having an inlet for exhaust gases, means for introducing an oxidizing fluid into said conduit for admixture with said gases, said conduit having an outlet portion containing a plurality of perforations, a container defining a chamber surrounding said outlet portion, said chamber having an internal wall surface of gold resistant to high temperature gases and highly reflective to radiations having wavelengths of from 0.6 to 10.0 microns, a discharge tube communicating with said chambers, and tapered metal tongues defining said perforations and extending towards said reflective surface.

2. Internal combustion engine exhaust gas oxidation apparatus according to claim 1 wherein said conduit is composed of a metal having relatively low thermal con ductivity.

3. Internal combustion engine exhaust gas oxidation apparatus comprising a conduit having an inlet for exhaust gases, means for introducing an oxidizing fluid into said conduit for admixture with said gases, said conduit having an outlet portion containing a plurality of perforations defined by tapered metal tongues extending outwardly from said conduit, a container defining a hollow combustion chamber surrounding said outlet portion, said chamber having an internal wall surface of gold, resistant to high temperature gases, and a discharge tube communicating with said chamber.

4. Internal combustion engine exhaust gas oxidation apparatus according to claim 3 wherein said conduit is composed of a metal having relatively low thermal conductivity.

5. Internal combustion engine exhaust gas oxidation apparatus comprising a conduit having an inlet for exhaust gases, means for introducing an oxidizing fluid into said conduit for admixture with said gases, said conduit having an outlet portion containing a plurality of perforations, a container defining a hollow combustion chamber surrounding said outlet portion, said chamber having an internal wall surface of gold, resistant to high temperature gases and highly reflective to thermal radiations having wavelengths of from 0.6 to 10.0 microns, and a discharge tube communicating with said chamber, whereby gases pass in direct contact with said internal wall surface.

6. Internal combustion engine exhaust gas oxidation apparatus according to claim 5 wherein a fluid tight housing encloses said container and provides a wall in spaced relationship with respect to said container.

7. Internal combustion engine exhaust gas oxidation apparatus according to claim 5 wherein said container has a gold external surface.

8. Internal combustion engine exhaust gas oxidation apparatus comprising a conduit having an inlet for exhaust gases, means for introducing an oxidizing fluid into said conduit for admixture with said gases, a container defining a hollow combustion chamber, said chamber having an internal wall surface of gold resistant to high temperature gases and highly reflective to thermal radiations having wavelengths of from 0.6 to 10.0 microns, said conduit opening into said chamber so that exhaust gases pass in direct contact with said internal wall surface, and a discharge communicating with said chamber.

9. Internal combustion engine exhaust gas oxidation apparatus as set forth in claim 8 wherein said conduit includes a converging area terminating in a throat, and said means for introducing an oxidizing fluid into said conduit includes an oxidizer inlet port communicating with said throat, and said combustion chamber is defined downstream of said throat.

10. Internal combustion engine exhaust gas oxidation apparatus comprising a conduit having an upstream port defining an inlet for engine exhaust gas and a downstream port for gas discharge, a reduced throat intermediate said ports, and an oxidizer inlet port communicating with said throat, said conduit having an internal wall surface between said throat and discharge port formed of gold so as to be resistant to high temperature gases and highly reflective to thermal radiations within the range of 0.6 to 10.0 microns.

11. Internal combustion engine exhaust gas oxidation apparatus according to claim 10 wherein an igniter is disposed in said conduit between said throat and discharge port.

12. Internal combustion engine exhaust gas oxidation apparatus according to claim 10 wherein said conduit diverges in a downstream direction from said throat through a distance of the order of five times the diameter of said throat.

13. Internal combustion engine exhaust gas oxidation apparatus according to claim 10 wherein metal filamentary material serving as igniter means is disposed in said conduit downstream of said throat.

14. Internal combustion engine exhaust gas oxidation appartus comprising a conduit having an upstream port defining an inlet for engine exhaust gas and a downstream port for gas discharge, means for introducing an oxidizer intermediate said ports, said conduit having an internal wall surface between the last mentioned means and said discharge port formed of gold so as to be resistant to high temperature gases and highly reflective to thermal radiations.

15. Internal combusition engine exhaust gas oxidation apparatus comprising a conduit having an inlet for exhaust gases, means for introducing an oxidizing fluid into said conduit for admixture with said gases, said conduit having an outlet portion containing a plurality of perforations, a container defining a chamber surrounding said outlet portion, said chamber having an internal wall surface formed of gold resistant to high temperature gases and highly reflective to radiations having wavelengths of from 0.6 to 10.0 microns, and a discharge tube communicating with said chamber.

16. Internal combustion engine exhaust gas oxidation apparatus according to claim wherein said internal wall surface is defined by a layer of gold having a thickness of at least 0.0003 inch.

17. Internal combustion engine exhaust gas oxidation apparatus comprising a conduit having an inlet for exhaust gases, means for introducing an oxidizing fluid into said conduit for admixture with said gases, said conduit having an outlet portion containing a plurality of perforations, a container defining a chamber surrounding said outlet portion, said chamber having internal and external wall surfaces formed of gold resistant to high temperature gases and highly reflective to radiations having wavelengths of from 0.6 to 10.0 microns, and a discharge tube communicating with said chamber.

18. Internal combustion engine exhaust gas oxidation apparatus as defined in claim 1 wherein said gold has a thickness of at least 0.0003 inch.

References Cited UNITED STATES PATENTS 2,005,249 6/ 1935 Tietig. 2,071,119 2/1937 Harger. 2,926,649 3/ 1960 Hicks. 3,233,699 2/1966 Plummet. 3,290,121 12/ 1966 Malkiewicz 23288 FOREIGN PATENTS 678,344 9/1952 Great Britain.

CARLTON R. CROYLE, Primary Examiner D. HART, Assistant Examiner US. 01. X.R.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2005249 *Feb 4, 1930Jun 18, 1935Chester TietigExhaust gas purifier
US2071119 *May 12, 1933Feb 16, 1937Harger JohnProcess and apparatus for treating furnace gases and exhaust gases from internal combustion engines
US2926649 *Oct 11, 1954Mar 1, 1960Hicks J ByronInternal combustion engines
US3233699 *Jan 2, 1962Feb 8, 1966Walter A PlummerHeat and sound insulating jacket for exhaust gas muffler and tail pipe assembly
US3290121 *Aug 22, 1963Dec 6, 1966Walker Mfg CoCatalytic muffler embodying internal reservoir
GB678344A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3874854 *Feb 1, 1973Apr 1, 1975Gen Motors CorpCatalytic converter
US3918937 *May 16, 1973Nov 11, 1975Ppg Industries IncParticulate lead trap system
US3918943 *Sep 28, 1973Nov 11, 1975Ppg Industries IncParticulate lead trap system
US3972687 *Mar 21, 1974Aug 3, 1976Paul Gillet GmbhCatalytic converter having pressurized-gas support means
US3987868 *Feb 22, 1974Oct 26, 1976Betts William MSilencing device for internal combustion engines
US4094644 *Dec 8, 1975Jun 13, 1978Uop Inc.Catalytic exhaust muffler for motorcycles
US4149611 *Jun 27, 1977Apr 17, 1979Yamaha Hatsudoki Kabushiki KaishaDevice for silencing the exhaust noise of internal combustion engines
US4475621 *Sep 10, 1982Oct 9, 1984Lennox Industries, Inc.Sound reduction means for pulsating type furnace
US4865820 *Aug 14, 1987Sep 12, 1989Davy Mckee CorporationGas mixer and distributor for reactor
US5326942 *Feb 9, 1993Jul 5, 1994Schmid Jerry WNoise suppression muffler for moisture laden exhaust gases & method
US7108838Oct 30, 2003Sep 19, 2006Conocophillips CompanyFeed mixer for a partial oxidation reactor
US7416571Mar 9, 2005Aug 26, 2008Conocophillips CompanyCompact mixer for the mixing of gaseous hydrocarbon and gaseous oxidants
US20050095186 *Oct 30, 2003May 5, 2005Conocophillips CompanyFeed mixer for a partial oxidation reactor
WO2004082811A1 *Dec 30, 2003Sep 30, 2004Kleen Up S R LMethod and apparatus for reducing combustion residues in exhaust gases
Classifications
U.S. Classification60/303, 181/227, 181/258, 423/213.2, 60/299, 422/182
International ClassificationF01N3/30, F01N3/26
Cooperative ClassificationF01N3/30, F01N3/26, Y02T10/20
European ClassificationF01N3/30, F01N3/26