Patent ID: 9664085
Date: 2017-05-30
CPC Classifications: B01D,F01N,F02D,Y02T

Claim:
1. An exhaust purification system comprising: at least one selective reduction catalyst arranged in an exhaust system of an internal combustion engine and configured to reduce nitrogen compounds contained in exhaust gas with ammonia generated from an aqueous urea solution as a reducing agent for purification of the exhaust gas; an aqueous urea solution injector injecting the aqueous urea solution into the selective reduction catalyst; a first capacitance sensor in the selective reduction catalyst detecting a first capacitance in the selective reduction catalyst, at least from a vicinity of an inlet of the selective reduction catalyst to a vicinity of a middle of the selective reduction catalyst in an exhaust gas flowing direction; a second capacitance sensor in the selective reduction catalyst detecting a second capacitance in the selective reduction catalyst, at least from a vicinity of a middle of the selective reduction catalyst to a vicinity of an outlet of the selective reduction catalyst in the exhaust gas flowing direction; and an electronic controller configured to