Automotive hydrocarbon adsorber system

摘要

An improved system for the control of combustion engine exhaust from a motor vehicle includes an adsorber (16) for the adsorption of hydrocarbons concentrated in the exhaust stream at engine startup, the adsorber (16) being of honeycomb shape which includes a peripheral channeled portion and a central channeled portion, the latter including an exhaust gas by-pass port (20) parallel with the channels (18), with the through-channels in the central portion of the honeycomb having a relatively high resistance to exhaust gas flow compared to the channels traversing the peripheral portion. Systems with reduced secondary air requirements and providing more efficient burn-off of the adsorbed hydrocarbons are also disclosed.