Selective catalytic reduction outlet mixing device

• Main Authors: JUJARE ARVIND, HUDGENS JASON, DESHMUKH SACHIN S, DRISCOLL JAMES JOSHUA, HEROLD SHAWN
• Format: Patent
• Language: English
• Published: 03.03.2015
• Subjects: BLASTING; ENGINE PLANTS IN GENERAL; FLUID DYNAMICS, i.e. METHODS OR MEANS FOR INFLUENCING THE FLOWOF GASES OR LIQUIDS; FLUID-PRESSURE ACTUATORS; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNALCOMBUSTION ENGINES; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES ORENGINES IN GENERAL; HEATING; HYDRAULICS OR PNEUMATICS IN GENERAL; LIGHTING; MACHINES OR ENGINES IN GENERAL; MEASURING; MECHANICAL ENGINEERING; PHYSICS; STEAM ENGINES; TESTING; TESTING STATIC OR DYNAMIC BALANCE OF MACHINES ORSTRUCTURES; TESTING STRUCTURES OR APPARATUS NOT OTHERWISE PROVIDED FOR; WEAPONS

Accurate measurement of exhaust gas compounds is necessary for correct operation of exhaust treatment systems, such as Selective Catalytic Reduction (SCR) units used in diesel engines. However, accurate sensor readings assume an even distribution of compounds in an exhaust stream in order to use a sampled measurement to be extrapolated to the compound concentrations in the full stream. A structure placed in an exhaust passage downstream of an SCR reaction unit causes turbulence in the exhaust gas while developing a minimal backpressure. This turbulence helps create a more uniform distribution of compounds in the exhaust. As a result, an exhaust gas sensor gives more accurate readings even when the sensor is placed in relatively close proximity to an output of the SCR system.