PROXIMALLY-CONNECTED SCR SYSTEM

• Main Authors: PHILLIPS PAUL RICHARD, JAMES ALEXANDER WYLIE
• Format: Patent
• Language: English; Japanese
• Published: 27.09.2018
• Subjects: BLASTING; CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; 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; THEIR RELEVANT APPARATUS; TRANSPORTING; WEAPONS

PROBLEM TO BE SOLVED: To provide a system for treating exhaust gas from a combustion engine and improve NOx conversion at a start of the engine.SOLUTION: A system includes a lean-combustion engine 10, an exhaust manifold 12 and a turbocharger 14. In regard to exhaust gas flow, an oxidation catalyst 28, a small SCR flow-through monolith 20 and an SCR wall surface flow filter 22 are provided. An injection point 24 of ammonia or an urea reducer is fitted to an upstream side of the small monolith, and a second injection point 26 of the reducer is disposed between the small monolith and the wall surface flow filter. The position of the SCR wall surface flow filter is less than 0.5 m between an outlet of the turbocharger and an outlet of the wall surface flow filter. As compared with the SCR wall surface flow filter, the small SCR flow-through monolith has a lower heat capacity, higher catalyst filling and a smaller volume.SELECTED DRAWING: Figure 1 【課題】燃焼エンジンからの排気ガスを処理するためのシステムと、エンジン始動時のＮＯｘ転換の向上を図る。【解決手段】システムは、希薄燃焼エンジン１０、排気マニホールド１２、ターボチャージャー１４とを有し、排気ガス流が、酸化触媒２８、小型ＳＣＲフロースルーモノリス２０、ＳＣＲ壁面流フィルタ２２を有する。アンモニア又は尿素還元体の注入点２４が、小型モノリスの上流に装着され、還元体の第２の注入点２６は、小型モノリスと壁面流フィルタとの間に配置される。ＳＣＲ壁面流フィルタの位置は、ターボチャージャーの出口と壁面流フィルタの出口との間で、０．５メートル未満とする。また、小型ＳＣＲフロースルーモノリスは、ＳＣＲ壁面流フィルタと比較して、低い熱容量及び高い触媒充填を備え、少ない体積を有する。【選択図】図１