EXHAUST EMISSION CONTROL DEVICE OF INTERNAL COMBUSTION ENGINE

• Main Authors: ODA TOMIHISA, ITO TAKEKAZU, TAUCHI YUTAKA, TOSHIOKA TOSHISUKE, ITO KAZUHIRO
• Format: Patent
• Language: English
• Published: 23.10.2008
• Subjects: BLASTING; ENGINE PLANTS IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNALCOMBUSTION ENGINES; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES ORENGINES IN GENERAL; HEATING; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; STEAM ENGINES; TRANSPORTING; WEAPONS

PROBLEM TO BE SOLVED: To secure high NOx conversion rate regardless of the temperature of an NOx selective reduction catalyst. SOLUTION: The NOx selective reduction catalyst 15 is disposed in the exhaust passage of an internal combustion engine. An oxidation catalyst 16 capable of controlling NOx at a lower temperature than in the case of the NOx selective reduction catalyst 15 is disposed in the exhaust passage of the engine on the downstream side of the NOx selective reduction catalyst 15. When the NOx selective reduction catalyst 15 is installed within the temperature range TM in which it can control NOx, urea necessary for reducing NOx is supplied to the NOx selective reduction catalyst 15. When the NOx selective reduction catalyst 15 is under the temperature range TM in which it can control NOx, urea necessary for controlling NOx is supplied to the oxidation catalyst 16. COPYRIGHT: (C)2009,JPO&INPIT