Willard A. Cutler

DPF Regeneration-Concept to Avoid Uncontrolled Regeneration During Idle

Significant particulate emission reductions of diesel engines can be achieved using diesel particulate filters (DPFs). Ceramic wall flow filters with a PM efficiency of >90% have proven to be effective components in emission control. The challenge for the application lies with the development and adaptation of a reliable regeneration strategy. The main focus is emission efficiency over the legally required durability periods, as well as over the useful vehicle life. It will be shown, that new DPF systems are characterized by a high degree of integration with the engine management system, to allow for initiation of the regeneration and its control for optimum DPF protection. Using selected cases, the optimum combination and tuning will be demonstrated for successful regenerations, taking into account DPF properties. For example, high DPF durability, good DPF regenerability, and low system pressure drop are balanced with engine based parameters like air mass flow, exhaust gas temperature, and exhaust oxygen content. Advanced system control techniques, such as tuning and optimization will be presented and discussed. New possibilities of the application of new robust and cost effective DPF systems will be shown.

Untersuchung der Eigenschaften neuer Dieselpartikelfilter

Eine neue Generation von Dieselpartikelfiltern basierend auf einer Aluminiumtitanat-Keramik ist von Corning entwickelt worden. Die neuen DuraTrap-AT-Filter verfugen uber eine extrem hohe Bestandigkeit gegenuber thermischen Spannungen, kombiniert mit einer hohen volumetrischen Warmespeicherfahigkeit. In dem vorliegenden Beitrag werden experimentelle Ergebnisse diskutiert, die mit dem neuen Material in Laborversuchen, am Motorprufstand und in Fahrzeugtests ermittelt wurden.

New Catalyzed Cordierite Diesel Particulate Filters for Heavy Duty Engine Applications

A family of cordierite DPF filters were developed and studied for their efficacy for catalyzed soot filter applications. In addition to porosity and median pore size of DPF filters, breadth of pore size distribution, microstructure, and pore connectivity have a profound influence not only in filter performance (pressure drop, catalyst coatability, and filtration efficiency) but also on mechanical and physical properties. Through filter material composition development, optimum values for the %porosity, median pore diameter, and breadth of the pore size distribution for minimizing pressure drop have been identified, leading to the development of a new family of high-porosity cordierite diesel particulate filters that possess a unique combination of high filtration efficiency, high strength, and very low clean and soot-loaded pressure drop in both the catalyzed and non-catalyzed states. By controlling the microstructure, the impact of the catalyst on pressure drop has been minimized. Soot-loaded pressure drops of these new filters in their catalyzed state are less than 50% of other catalyzed commercial filters with the same cell geometry. In contrast, large pore size and high porosity filters raise concerns of low filtration efficiency and low mechanical strength at both catalyzed and uncatalyzed states. Addition of catalyst into the filters seems to have little or no impact on filter filtration efficiency, static mechanical and thermal properties.

Evaluation of new diesel particulate filters based on stabilized aluminium titanate

A new generation of wall-flow diesel particulate filters based on an aluminium titanate composition has recently been developed by Corning, and marketed as the Corning Dura-Trap AT filter. The new material combines extremely high resistance to thermal stresses with a high bulk heat capacity. In this article, the test results obtained with this new material in laboratory tests, engine bench experiments and on-road vehicle durability runs are presented and discussed.