# US 11,111,835 B2 · Injector for injecting a gaseous reducing agent into an exhaust gas stream, comprising at least one anti-backflow device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,111,835 B2 - Document ID: US11111835B2 - Status: Granted - Kind: B2 - Application number: 16/662,174 - Filed: 2019-10-24 - Published: 2020-04-30 - Granted: 2021-09-07 - Earliest claimed: 2018-10-26 - Assignees: Faurecia Systemes D'Echappement - Applicants: Faurecia Systemes D'Echappement - Inventors: Thibaut Jeannerot; James Holloway; Jorn Hansen; Ludovic Geant - Web page: https://patentgrep.com/patent/US11111835B2 ## CPC - F01N 3/2066: {Selective catalytic reduction [SCR]} - B01F 23/2132: {using nozzles} - B01F 25/314: wherein additional components are introduced at the circumference of the conduit - F01N 2610/02: the substance being ammonia or urea - F01N 2610/06: the substance being in the gaseous form - F01N 2610/10: the substance being heated, e.g. by heating tank or supply line of the added substance - F01N 2610/105: Control thereof - F01N 2610/14: Arrangements for the supply of substances, e.g. conduits - F01N 2610/1453: Sprayers or atomisers; Arrangement thereof in the exhaust apparatus - F01N 2610/1486: Means to prevent the substance from freezing - F16K 15/044: {spring-loaded} - 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) - B01F: MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING (mixing paints B44D3/06) - F16K: VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING {(devices for emptying and evacuating the excess liquid in valves or conduits F16L55/07)} - Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An injector comprises at least one injection nozzle, a dosing system to provide a dosed flow of reducing agent to the at least one or each injection nozzle, and an injection line fluidically connecting the dosing system to the at least one or each injection nozzle. The injection line comprises an upstream pipe fluidically connected to the dosing system, at least one downstream pipe fluidically connected to a respective injection nozzle, and at least one anti-backflow device to avoid or minimize fluidic flow from the at least one or each downstream pipe toward the upstream pipe. ## Claims ### Claim 1 An injector for injecting a gaseous reducing agent into an exhaust gas stream of an internal combustion engine, the injector comprising: at least one injection nozzle; a dosing system to provide a dosed flow of reducing agent to the at least one or each injection nozzle; and an injection line fluidically connecting the dosing system to the at least one or each injection nozzle, wherein the injection line comprises an upstream pipe fluidically connected to the dosing system, at least one downstream pipe fluidically connected to a respective injection nozzle, and at least one anti-backflow device to avoid or minimize fluidic flow from the at least one or each downstream pipe toward the upstream pipe, and wherein the at least one anti-backflow device has at least one constriction with a reduced flow-section relative to the at least one downstream pipe, and wherein a ratio between a flow section of the at least one downstream pipe and a flow section of the at least one constriction is comprised between 4 and 25. ### Claim 2 (depends on 1) The injector of claim 1, wherein the at least one anti-backflow device is configured to allow fluidic flow from the upstream pipe toward the at least one downstream pipe. ### Claim 3 (depends on 1) The injector of claim 1, wherein the at least one constriction has a reduced flow-section relative to the upstream pipe and comprises a pinched pipe section that connects the at least one downstream pipe and the upstream pipe. ### Claim 4 (depends on 1) The injector of claim 1, wherein the at least one anti-backflow device comprises at least one chicane. ### Claim 5 (depends on 1) The injector of claim 1, wherein the upstream pipe is configured to be heated during working phases of the internal combustion engine. ### Claim 6 (depends on 1) The injector of claim 1, wherein the at least one anti-backflow device comprises at least one chicane that is located internally within the injection line so that a flow path internally within the injection line is sinuous. ### Claim 7 (depends on 1) The injector of claim 1, comprising a heater to heat the at least one anti-backflow device. ### Claim 8 (depends on 7) The injector of claim 7, wherein the heater is configured to heat the at least one anti-backflow device during a starting phase of the internal combustion engine. ### Claim 9 An exhaust line for an internal combustion engine comprising: a mixer configured to be crossed by an exhaust gas stream produced by the internal combustion engine; an injector to inject a reducing agent into said exhaust gas stream, the injector comprising at least one injection nozzle; a dosing system to provide a dosed flow of the reducing agent to the or each injection nozzle; and an injection line fluidically connecting the dosing system to the at least one or each injection nozzle, wherein the injection line comprises an upstream pipe fluidically connected to the dosing system, at least one downstream pipe fluidically connected to a respective injection nozzle, and at least one anti-backflow device to avoid or minimize fluidic flow from the at least one or each downstream pipe toward the upstream pipe, and wherein the at least one anti-backflow device has at least one constriction that comprises a reduced flow-section relative to the at least one downstream pipe, and/or comprises at least one chicane that is located internally within the injection line, and wherein a ratio between a flow section of the at least one downstream pipe and a flow section of the at least one constriction is comprised between 4 and 25. ### Claim 10 (depends on 9) The exhaust line of claim 9, wherein the at least one downstream pipe extends from the at least one injection nozzle to the at least one anti-backflow device and comprises an outer portion extending outside the mixer, said outer portion having a length that is less than 2 m. ### Claim 11 (depends on 9) The exhaust line of claim 9, wherein the at least one downstream pipe extends from the at least one injection nozzle to the at least one anti-backflow device and comprises an outer portion extending outside the mixer, said outer portion having a length that is less than 20 cm. ### Claim 12 (depends on 9) The exhaust line of claim 9, wherein the at least one anti-backflow device is located inside the mixer. ### Claim 13 (depends on 9) The exhaust line of anyone of claim 9, comprising an exhaust pipe to guide exhaust gas, at least part of the upstream pipe extending close to said exhaust pipe so that the upstream pipe is heated by the exhaust pipe due to exhaust gas flowing through said exhaust pipe. ### Claim 14 (depends on 9) The exhaust line of claim 9, wherein the at least one constriction has a reduced flow-section relative to the at least one downstream pipe and the upstream pipe, and wherein the at least one constriction comprises a pinched pipe section that connects the at least one downstream pipe and the upstream pipe. ### Claim 15 (depends on 9) The exhaust line of claim 9, wherein the at least one constriction comprises at least one chicane that is located internally within the injection line so that a flow path internally within the injection line is sinuous. ### Claim 16 An automotive vehicle comprising: an exhaust line for an internal combustion engine comprising a mixer configured to be crossed by an exhaust gas stream produced by the internal combustion engine; an injector to inject a reducing agent into said exhaust gas stream, the injector comprising at least one injection nozzle; a dosing system to provide a dosed flow of the reducing agent to the at least one or each injection nozzle; and an injection line fluidically connecting the dosing system to the at least one or each injection nozzle, wherein the injection line comprises an upstream pipe fluidically connected to the dosing system, at least one downstream pipe fluidically connected to a respective injection nozzle, and at least one anti-backflow device to avoid or minimize fluidic flow from the at least one or each downstream pipe toward the upstream pipe, and wherein the at least one anti-backflow device has at least one constriction that comprises a reduced flow-section relative to the at least one downstream pipe, and/or comprises at least one chicane that is located internally within the injection line, and wherein a ratio between a flow section of the at least one downstream pipe and a flow section of the at least one constriction is comprised between 4 and 25. ### Claim 17 (depends on 16) The automotive vehicle of claim 16, wherein the at least one constriction has a reduced flow-section relative to the at least one downstream pipe and the upstream pipe, and wherein the at least one constriction comprises a pinched pipe section that connects the at least one downstream pipe and the upstream pipe. ### Claim 18 (depends on 16) The automotive vehicle of claim 16, wherein the at least one constriction comprises at least one chicane that is located internally within the injection line so that a flow path internally within the injection line is sinuous.