Patent ID: 6170259
Filing Date: 2001-01-09
Classification: B01D,F01N,F02M

Abstract:
Emission control system for an internal-combustion engine, having at least two nitrogen oxide adsorbers arranged in parallel for alternating periodic adsorption and desorption of nitrogen oxides contained in exhaust gas of the internal-combustion engine and devices for providing a desorption gas flow for each of the nitrogen oxide adsorbers running in desorption mode,whereinthe desorption gas flow providing devices have a desorption gas pipe which the nitrogen oxide adsorbers share and which has an externally heatable catalyst, a lambda probe operatively arranged between the externally heatable catalyst and the nitrogen oxide adsorbers, and devices for feeding a mixture of air and/or exhaust gas as well as fuel at an at least stoichiometric, controllable proportion, to the externally heatable catalyst, such that the externally heatable catalyst burns the fed mixture to form a desorbing gas flow which is fed to the nitrogen oxide adsorber in the desorption mode, by way of an associated desorption pipe branch with a predefinable lambda value of the desorbing gas flow being adjusted by the lambda probe.