Fleetguard, Inc.

Scott Cole

Rahul Mital

Bradlee J Stroia

Michael J Cunningham

Robert C Yu

Mike Nagel

The present invention provides for an NOx adsorber aftertreatment system for internal combustion engines which utilizes a parallel arrangement of an adsorber catalyst and a bypass. The exhaust flow from the engine is routed through the adsorber during lean operation. At a predetermined regeneration time (for example, when the adsorber catalyst is 20% full), the exhaust gas flow is reduced through the parallel leg that contains the adsorber catalyst to be regenerated (e.g., 20% through the catalyst leg, 80% of the flow to the bypass leg). A quantity of hydrocarbon is injected into the reduced-flow catalyst leg in order to make the mixture rich. Since the flow has been reduced in this leg, only a small fraction of the amount of hydrocarbon that would have been required to make the mixture rich during full flow is required. This will result in a substantial reduction in the fuel penalty incurred for regeneration of the adsorber catalyst. Once the leg has been regenerated, the exhaust flow is switched to flow 100% through the adsorber leg.

NOx adsorber aftertreatment system for internal combustion engines

The present invention provides for a system and process for enhancing internal combustion engine aftertreatment applications by superheated fuel injection. The system includes a fuel supply upstream of a fuel injector of an aftertreatment application. The system also includes a heater for heating the fuel in the fuel supply. A temperature controller can be used to maintain the heated fuel in a liquid form. When liquid fuel in the pressurized fuel supply is heated, then upon exiting the injector the pressure of the fuel drops rapidly, resulting in atomization of the liquid. The vaporized fuel thereby produced is comprised of extremely small droplets and is elevated in temperature, which reduces the possibility of condensation on internal surfaces of the aftertreatment system. This fine droplet size and resistance to condensation enhances the NOx conversion efficiency of adsorbers. Problems related to premature aging of catalysts and fuel penalties can also be reduced.

System and method for enhancing internal combustion engine aftertreatment applications by superheated fuel injection

The present invention provides for an NOx adsorber aftertreatment system for internal combustion engines which utilizes adsorber catalysts arranged in parallel. The exhaust flow from the engine is divided in a predetermined ratio between the two catalysts during lean operation (e.g. 50-50). At a predetermined regeneration time (for example, when the adsorber catalyst is 20% full), the exhaust gas flow is reduced through the parallel leg that is to be regenerated (e.g., 20% through the leg to be regenerated, 80% of the flow to the other leg). A quantity of hydrocarbon is injected into the reduced-flow leg in order to make the mixture rich. Since the flow has been reduced in this leg, only a small fraction of the amount of hydrocarbon that would have been required to make the mixture rich during full flow is required. This will result in a substantial reduction in the fuel penalty incurred for regeneration of the adsorber catalyst. Once the leg has been regenerated, the flow distribution between the parallel legs is reversed, and the other catalyst leg is regenerated while the other side (which is now clean) receives the majority of the exhaust flow. Another advantage of the present invention is that since NOx is being stored in one leg while the other leg is being regenerated, the regeneration operation can be performed for a longer period of time, resulting in greater regeneration efficiency. Once both catalyst legs have been regenerated, the exhaust flow is adjusted back to normal (e.g. 50-50) until the catalysts are again ready for regeneration and reduction.

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Columbus, IN, United States of America

Scott Cole