Emission control system for internal combustion engine

摘要

An emission control system for an internal combustion engine (1) includes a NOx catalyst (41) disposed in an exhaust system (40) of the internal combustion engine and having a property of promoting reactions for reducing NOx when a concentration of a reducing substance in an exhaust gas becomes high, and reductant adding means (14, 16, 17, P2) for adding a reducing agent to the exhaust gas flowing into the NOx catalyst through the exhaust system. The emission control system further includes control means (80) for controlling the reductant adding means to add the reducing agent in the form of droplets to the exhaust gas.