Patent ID: 7475533
Filing Date: 2009-01-13
Classification: B01D,F01N,H05H,Y02A,Y02T

Abstract:
1. A method for controlling an exhaust gas purifying apparatus, the exhaust gas purifying apparatus including a NO x purifying catalyst disposed in an exhaust gas pipe through which an exhaust gas flows; a plasma generator for converting a gas into a plasma and supplying the plasma to the exhaust pipe at the upstream of the NO x purifying catalyst; a switching device for selectively supplying one of a recirculated exhaust gas and air as a gas to be converted into a plasma to the plasma generator; and an injector for adding a reducing agent to the gas to be converted into a plasma or a plasma converted from the gas by the plasma generator; the method comprising: when a predetermined reducing condition is satisfied, supplying the recirculated exhaust gas to the plasma generator with use of the switching device, and converting the recirculated exhaust gas into a plasma by the plasma generator with a reducing agent being added by the injector; and when a predetermined oxidizing condition is satisfied, supplying the air to the plasma generator with use of the switching device, and converting the air into a plasma by the plasma generator without a reducing agent being added by the injector.