# US 9,003,792 B2 · Exhaust aftertreatment and exhaust gas recirculation systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,003,792 B2 - Document ID: US9003792B2 - Status: Granted - Kind: B2 - Application number: 13/440,159 - Filed: 2012-04-05 - Published: 2013-10-10 - Granted: 2015-04-14 - Earliest claimed: 2012-04-05 - Assignees: GM Global Technology Operations LLC - Applicants: Manuel Angel Gonzalez Delgado; Julian C. Tan; Joshua Clifford Bedford; Yong Miao; Naser I. Hineiti; Steven M. Yocum - Inventors: Manuel Angel Gonzalez Delgado; Julian C. Tan; Joshua Clifford Bedford; Yong Miao; Naser I. Hineiti; Steven M. Yocum - Web page: https://patentgrep.com/patent/US9003792B2 ## CPC - F01N 3/00: Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust (electric control F01N9/00; monitoring or diagnostic devices for exhaust-gas treatment apparatus F01N11/00) - F01N 3/021: by means of filters - F01N 3/035: with catalytic reactors - F01N 3/10: by thermal or catalytic conversion of noxious components of exhaust - F01N 3/103: {Oxidation catalysts for HC and CO only} - F01N 3/2066: {Selective catalytic reduction [SCR]} - F02M 26/06: Low pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust downstream of the turbocharger turbine and reintroduced into the intake system upstream of the compressor - F02M 26/15: in relation to engine exhaust purifying apparatus - F01N 2610/02: the substance being ammonia or urea - Y02A 50/20: Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters - Y02T 10/12: Improving ICE efficiencies - F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16) - F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF - Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract In an exemplary embodiment, an internal combustion engine includes an oxidation catalyst configured to receive an exhaust gas flow from the internal combustion engine, a urea injector positioned downstream of the oxidation catalyst to inject a urea flow into the exhaust gas flow and a mixer positioned downstream of the urea injector to mix the exhaust gas flow and the urea flow to form a mixed exhaust gas and urea flow. The engine also includes a particulate filter and catalytic reduction assembly positioned downstream of the mixer to receive the mixed exhaust and urea flow from the mixer to form a treated exhaust gas flow and an exhaust gas recirculation system coupled to the particulate filter to receive a portion of the treated exhaust gas flow and recirculate the portion of the exhaust gas flow to be mixed with a fresh air flow for the internal combustion engine. ## Claims ### Claim 1 An internal combustion engine comprising: a turbocharger configured to receive an exhaust gas flow from the internal combustion engine; an oxidation catalyst close coupled to the turbocharger to receive the exhaust gas flow from the turbocharger; a conduit coupled to the oxidation catalyst to receive the exhaust gas flow from the oxidation catalyst and an emission fluid flow from an injector; a mixer coupled to the conduit to receive the exhaust gas flow and the emission fluid flow from the conduit and to form a mixed exhaust gas and emission fluid flow; a particulate filter and catalytic reduction assembly close coupled to the mixer to receive the mixed exhaust gas and emission fluid flow from the mixer to form a treated exhaust gas flow; and an exhaust gas recirculation system coupled to the particulate filter and catalytic reduction assembly to receive a portion of the treated exhaust gas flow and recirculate the portion of the exhaust gas flow to be mixed with a fresh air flow for the internal combustion engine, wherein the oxidation catalyst, conduit, mixer, particulate filter and catalytic reduction assembly and exhaust gas recirculation system are each located in an engine compartment. ### Claim 2 (depends on 1) The internal combustion engine of claim 1, wherein the exhaust gas recirculation system comprises a cooler to cool the recirculation exhaust gas flow prior to mixing with the fresh air flow. ### Claim 3 (depends on 2) The internal combustion engine of claim 2, wherein the recirculation exhaust gas flow is substantially lower pressure compared to the exhaust gas exiting from the internal combustion engine. ### Claim 4 (depends on 2) The internal combustion engine of claim 2, wherein the exhaust gas recirculation system comprises a filter to filter the recirculation exhaust gas flow prior to mixing with the fresh air flow. ### Claim 5 (depends on 1) The internal combustion engine of claim 1, wherein the turbocharger receives the fresh air flow mixed with the recirculation exhaust gas flow in a compressor and receives the exhaust gas flow from the internal combustion engine in a turbine. ### Claim 6 (depends on 1) The internal combustion engine of claim 1, comprising an inlet cone coupled to the mixer and the particulate filter and catalytic reduction assembly to distribute the mixed exhaust and emission fluid flow from the mixer across a receiving portion of the particulate filter and catalytic reduction assembly. ### Claim 7 (depends on 1) The internal combustion engine of claim 1, wherein the oxidation catalyst, conduit, mixer, particulate filter and catalytic reduction assembly and exhaust gas recirculation system are not located beneath a floor of a vehicle housing the internal combustion engine. ### Claim 8 (depends on 1) The internal combustion engine of claim 1, wherein the emission fluid flow comprises a urea fluid flow. ### Claim 9 An exhaust aftertreatment system for an internal combustion engine comprising: an oxidation catalyst configured to receive an exhaust gas flow from the internal combustion engine; a urea injector positioned downstream of the oxidation catalyst to inject a urea flow into the exhaust gas flow; a mixer positioned downstream of the urea injector to mix the exhaust gas flow and the urea flow to form a mixed exhaust gas and urea flow; a particulate filter and catalytic reduction assembly positioned downstream of the mixer to receive the mixed exhaust and urea flow from the mixer to form a treated exhaust gas flow; an exhaust gas recirculation system coupled to the particulate filter to receive a portion of the treated exhaust gas flow and direct it to be mixed with a fresh air flow for the internal combustion engine, wherein the oxidation catalyst, urea injector, mixer, particulate filter and exhaust gas recirculation system are each located in an engine compartment; and an underfloor catalytic reduction assembly positioned downstream of the particulate filter and catalytic reduction assembly. ### Claim 10 (depends on 9) The exhaust aftertreatment system for an internal combustion engine of claim 9, comprising a turbocharger to receive the fresh air flow mixed with the recirculation exhaust gas flow in a compressor and to receive the exhaust gas flow from the internal combustion engine in a turbine, the oxidation catalyst being close coupled to the turbocharger. ### Claim 11 (depends on 9) The exhaust aftertreatment system for an internal combustion engine of claim 9, wherein the exhaust gas recirculation system comprises a cooler to cool the recirculation exhaust gas flow prior to mixing with the fresh air flow. ### Claim 12 (depends on 9) The exhaust aftertreatment system for an internal combustion engine of claim 9, wherein the recirculation exhaust gas flow is substantially lower pressure than the exhaust gas flow exiting the internal combustion engine. ### Claim 13 (depends on 9) The exhaust aftertreatment system for an internal combustion engine of claim 9, wherein the exhaust gas recirculation system comprises a filter to filter the recirculation exhaust gas flow prior to mixing with the fresh air flow. ### Claim 14 (depends on 9) The exhaust aftertreatment system for an internal combustion engine of claim 9, wherein the oxidation catalyst, conduit, mixer, particulate filter and exhaust gas recirculation system are close coupled to the internal combustion engine. ### Claim 15 An internal combustion engine exhaust aftertreatment system comprising: an oxidation catalyst configured to receive an exhaust gas flow from the internal combustion engine; a conduit coupled to the oxidation catalyst to receive the exhaust gas flow from the oxidation catalyst and a urea flow from an injector; a mixer coupled to the conduit to receive the exhaust gas flow and the urea flow from the conduit and to form a mixed exhaust gas and urea flow; a particulate filter and catalytic reduction assembly coupled to the mixer to receive the mixed exhaust and urea flow from the mixer to form a treated exhaust gas flow; and an exhaust gas recirculation system to receive a portion of the treated exhaust gas flow and direct it to be mixed with a fresh air flow for the internal combustion engine, wherein the oxidation catalyst, urea injector, mixer, particulate filter and catalytic reduction assembly and exhaust gas recirculation system are closely coupled to the internal combustion engine. ### Claim 16 (depends on 15) The internal combustion engine exhaust aftertreatment system of claim 15, wherein the exhaust gas recirculation system comprises a cooler and a filter to cool and filter, respectively, the recirculation exhaust gas flow. ### Claim 17 (depends on 15) The internal combustion engine exhaust aftertreatment system of claim 15, wherein the oxidation catalyst, urea injector, mixer, particulate filter and catalytic reduction assembly and exhaust gas recirculation system are each located in the engine compartment. ### Claim 18 (depends on 15) The internal combustion engine exhaust aftertreatment system of claim 15, wherein the recirculation exhaust gas flow is substantially lower pressure compared to the exhaust gas flow exiting the internal combustion engine. ### Claim 19 (depends on 15) The internal combustion engine exhaust aftertreatment system of claim 15, comprising a turbocharger to receive the fresh air flow and recirculated exhaust gas in a compressor and to receive the exhaust gas flow from the internal combustion engine in a turbine.