Patent ID: 6009703
Filing Date: 2000-01-04
Classification: F01N,Y02A,Y02T

Abstract:
An assembly for elimination of nitrogen oxides present in the exhaust gas of an internal-combustion engine, said assembly being part of an exhaust line coming from the engine and comprising:a nitrogen oxides conversion means,a heat exchanger for cooling said exhaust gas placed in a bypass line, said bypass line having an outlet into said exhaust line situated upstream from said conversion means and an inlet from said exhaust line upstream from said outlet,characterized in that said conversion means comprises several catalysts placed in said exhaust line, said catalysts having non-coinciding temperature ranges for which nitrogen oxides conversion is below a certain threshold (C.sub.min), and in that at least one valve is placed at the inlet of said bypass line in order to modulate the flow of gas between said bypass line and said exhaust line, so that said exhaust gas reaches said catalysts at a temperature where at least one of said catalysts is active.