Patent ID: 6996975
Filing Date: 2006-02-14
Classification: F01N,Y02A,Y02T

Abstract:
1. An exhaust treatment apparatus, comprising: a first ammonia injector configured to inject a first charge of ammonia into an exhaust stream; a first catalyst bed positioned to receive the exhaust stream with the first charge of ammonia and adapted to catalyze a reaction between NO a second ammonia injector for injecting a second ammonia charge into an effluent from the first catalyst bed; a second catalyst bed positioned to receive the effluent from the first catalyst bed with the second charge of ammonia and adapted to catalyze a reaction between NO an NO wherein the apparatus is adapted for use in a vehicle exhaust system; the controller controls the second ammonia charge based at least in part on data from the NO the second ammonia charge is controlled to be less than a stoichiometric amount a stoichiometric amount being an amount of ammonia just sufficient to reduce all the NO