An improved selective catalytic reduction system and method

• Main Authors: LOCKYER THOMAS, SILVER RONALD, GAYNOR PAUL, HARGRAVE GRAHAM, REID BEN
• Format: Patent
• Language: Chinese; English
• Published: 05.11.2019
• 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; STEAM ENGINES; WEAPONS

A selective catalytic reduction (SCR) system for treating exhaust gases in an exhaust passage is provided. The system comprises a first catalyst (30) for converting urea to ammonia, the first catalystbeing located in the passage (10) and having an upstream face (31) and a downstream face (33). The upstream face (31) is at a right angle to an axial flow path (A) through the passage (10). The system further comprises a second catalyst (40) for converting NOx to nitrogen gas and water in the presence of ammonia, with the second catalyst being located in the passage (10) downstream of the first catalyst (30). A diesel exhaust fluid (DEF) dosing unit (50) is located upstream of the first catalyst (30). The dosing unit (50) comprises a nozzle (56) arranged so as to inject DEF directly onto theupstream face (31) of the first catalyst (30). 提供了一种用于处理排气通道中的排气气体的选择性催化还原(SCR)系统。该系统包括用于将尿素转化成氨的第一催化器(30)，该第一催化器位于通道(10)中并且具有上游面(31)和下游面(33)。上游面(31)与穿过通道(10)的轴向流动路径(A)成直角。该系统还包括用于在氨的存在下将NOx转化为氮气和水的第二催化器(40)，其中第二催化器在第一催化器(30)的