Automotive hydrocarbon adsorber system

A combustion engine exhaust treatment system comprising:

• (i) an adsorber mounted in an enclosure positioned in an engine exhaust system for treating exhaust gases from an engine, the adsorber comprising a honeycomb structure having a central portion and a peripheral portion, each portion being provided with multiple through-channels having hydrocarbon-adsorptive channel walls extending from an inlet face to an outlet face of the honeycomb structure and the central portion being provided with a by-pass port extending from the inlet face to the outlet face;
• (ii) a catalytic converter mounted downstream of the adsorber, and
• (iii) a diverter line having an outlet within the enclosure and upstream of the by-pass port for delivering a diversion fluid through the outlet from a fluid source external to the enclosure;
• wherein the through-channels comprise a first plurality of channels proximate to the by-pass port having a relatively high resistance to exhaust gas flow and a second plurality of channels traversing the peripheral portion having a relatively low resistance to exhaust gas flow, and wherein the first plurality of channels have an average hydraulic diameter which is less than an average hydraulic diameter of the second plurality of channels.

A combustion engine exhaust treatment system comprising:

• (i) an adsorber mounted in an enclosure positioned in an engine exhaust system for treating exhaust gases from an engine, the adsorber comprising a honeycomb structure having a central portion and a peripheral portion, each portion being provided with multiple through-channels having hydrocarbon-adsorptive channel walls extending from an inlet face to an outlet face of the honeycomb structure and the central portion being provided with a bypass port extending from the inlet face to the outlet face;
• (ii) an exhaust gas flow concentrator mounted in the enclosure at a-position upstream from the adsorber, the concentrator being positioned to collect and direct exhaust gases entering the enclosure toward and into the by-pass port;
• (iii) a catalytic converter mounted downstream of the adsorber, and
• (iv) a diverter line having an outlet within the enclosure and upstream of the by-pass port for delivering a diversion fluid through the outlet from a fluid source external to the enclosure;
• wherein the through-channels of the adsorber comprise a first plurality of channels proximate to the by-pass port having a relatively high resistance to exhaust gas flow and a second plurality of channels traversing the peripheral portion having a relatively low resistance to exhaust gas flow;
• and wherein the first plurality of channels have an average hydraulic diameter which is less than an average hydraulic diameter of the second plurality of channels.

A combustion engine exhaust treatment system comprising:

• (i) an exhaust conduit supplying an exhaust gas from a combustion engine to a first catalytic converter mounted in an enclosure downstream from the engine;
• (ii) an adsorber mounted in an enclosure downstream of the first converter for receiving exhaust gas therefrom, the adsorber comprising a honeycomb structure having a central portion and a peripheral portion, each portion being provided with multiple through-channels having hydrocarbon-adsorptive channel walls extending from an inlet face to an outlet face of the honeycomb structure and the central portion being provided with a by-pass port extending from the inlet face to the outlet face;
• (iii) a burn-off catalytic converter mounted downstream of the adsorber, and
• (iv) a diverter line having an outlet within the enclosure and upstream of the by-pass port for delivering a diversion fluid comprising secondary air through the outlet from a source external to the enclosure;
• wherein the diverter line constitutes the primary or sole means for injecting a supply of secondary air into the exhaust treatment system, and wherein the multiple through-channels in the central portion have an average hydraulic diameter which is less than an average hydraulic diameter of the multiple through-channels in the peripheral portion.

A combustion engine exhaust treatment system comprising:

• (i) an exhaust conduit supplying exhaust gas from a combustion engine to an adsorber mounted in an enclosure downstream of the engine, the adsorber comprising a honeycomb structure having a central portion and a peripheral portion, each portion being provided with multiple through-channels having hydrocarbon-adsorptive channel walls extending from an inlet face to an outlet face of the structure and the central portion being provided with a by-pass port extending from the inlet face to the outlet face;
• (ii) a catalytic converter mounted downstream of the adsorber;
• (iii) a diverter line having an outlet within the enclosure and upstream of the by-pass port for delivering a diversion fluid through the outlet from a fluid source external to the enclosure;
• and
• (iv) exhaust gas mixing means disposed between the catalytic converter and the by-pass port, the mixing means being positioned to deflect and mix exhaust gases traversing the by-pass port.