Patent ID: 8117834
Filing Date: 2012-02-21
Classification: B01D,F01N,F02B,Y02A,Y02T,Y10T

Abstract:
1. An exhaust purification device of an internal combustion engine arranging an NO x selective reduction catalyst in an engine exhaust passage, feeding a urea aqueous solution stored in a urea aqueous solution tank to the NO x selective reduction catalyst, and using ammonia produced from the urea aqueous solution to selectively reduce NO x contained in an exhaust gas, wherein urea aqueous solution refill judging means for judging if the urea aqueous solution has been refilled in the urea aqueous solution tank and NO x purification rate judging means for judging if the NO x purification rate has fallen to an allowable level or less are provided and, urea aqueous solution abnormality judging means for judging if the refilled urea aqueous solution is abnormal when it is judged that the NO x purification rate has fallen to the allowable level or less at the time of engine operation right after the urea aqueous solution has been refilled in the urea aqueous solution tank.