Abstract: In a method for purifying exhaust gases in particular from lean-burn internal combustion engines having an exhaust-gas converter with a heat exchanger and catalysts arranged in inflow and/or outflow passages, the heat exchanger exhaust gas which flows in is heated by heat exchange with exhaust gas which flows. The incoming exhaust gas enters the inflow passages without encountering any obstacle susceptible to blockages, and flows through the inflow passages to a diversion region. Heat is fed to the exhaust gas by means of a burner. The burner is operated with fuel, air and engine exhaust gas in such a way that it supplies either an oxidizing or a reducing exhaust gas. Burner exhaust gas is admixed to the gas which emerges from the inflow passages and, together with this gas, enters the outflow passages, where nitrogen oxides are removed from it by a deNOxing catalyst present in the outflow passages.

Abstract: In a method for purifying exhaust gases in particular from lean-burn internal combustion engines having an exhaust-gas converter with a heat exchanger and catalysts arranged in inflow and/or outflow passages, the heat exchanger exhaust gas which flows in is heated by heat exchange with exhaust gas which flows. The incoming exhaust gas enters the inflow passages without encountering any obstacle susceptible to blockages, and flows through the inflow passages to a diversion region. Heat is fed to the exhaust gas by means of a burner. The burner is operated with fuel, air and engine exhaust gas in such a way that it supplies either an oxidizing or a reducing exhaust gas. Burner exhaust gas is admixed to the gas which emerges from the inflow passages and, together with this gas, enters the outflow passages, where nitrogen oxides are removed from it by a deNOxing catalyst present in the outflow passages.