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The development of new designs of a diesel particulate control system is discussed herein. The system employs a single high collection efficiency ceramic monolith to filter the particulate emissions of the engine. Regeneration is achieved by intermittent pulses of pressurized reverse-flow air. After every regeneration the soot is collected at the bottom of the device where it is burned in an incinerator chamber. Different configurations of the system were tested satisfactorily for performance and durability for 100 hrs, coupled to a small experimental engine which was sooting at high rates. Subsequently, a system incorporating a long ventless chamber fitted with an electric burner was mounted on a diesel passenger car and tested for on-road performance evaluation and further development.

The development of an Aerodynamically Regenerated Trap (ART) with a flow-through incinerator section is discussed herein. The ART system presented herein employes a single high-collection efficiency ceramic monolith to filter particulate emissions. Regeneration is performed aerodynamically, using compressed air flowing in the direction opposite to the exhaust flow. Dislodged particulates are captured in the incineration section of the trap directly below the ceramic monolith, where they are burned using an electric heater. This work concentrates on the design and development of the incinerator sections of the diesel particulate trap, whose function is to retain the soot from the regeneration air stream, without impeding the flow of the regeneration air itself.

This is an optimization study on the use of filtered exhaust gas recirculation (EGR) to reduce the NO emissions of diesel engines. Control of the particulate emissions and provisions for filtered EGR were achieved by an Aerodynamically Regenerated Trap (ART) with collection efficiencies in the order of 99%. The amount of EGR was regulated to provide for substantial NO reduction, without unacceptably decreasing the thermal efficiency of the engine or increasing the CO emissions. EGR regulation was accomplished by monitoring the injection pump setting which was correlated to the fuel flow rate, the speed of the engine, the amount of EGR flow, and the ambient air temperature. Through these parameters, the mixture strength expressed as the equivalence ratio, ϕ, was calculated and related to the power output of the engine. Thus, a map of engine performance parameters was generated and related to measured NO and CO emissions.