Heating and desulfation of the main nitrogen oxide storage catalyst, in a multi-channel IC motor exhaust system, uses primary lean and rich catalysts to pass flows to it and maintain a minimum desulfation temperature

摘要

The system is for heating and desulfation of the main catalyst (13), in a multi-channel exhaust system from a multi-cylinder vehicle internal combustion motor, where at least two primary catalysts are in parallel in front of it as a rich catalyst (12) and a lean catalyst (11). During the desulfation time span of the nitrogen oxide storage main catalyst, rich and lean exhaust gas flows pass from the two primary catalysts with their lambda values set within rich and lean ranges, and the desulfation action uses oxygen held in the main catalyst. The curves show the oxygen content (17) stored in the main catalyst and the oxygen content (18) of the two primary catalysts, in time phases of the process.