Advanced Diesel Particulate Filter Design for Lifetime Pressure Drop Solution in Light Duty Applications 2007-01-0042

Highly efficient wall-flow diesel particulate filters (DPF) are the primary means of PM emissions control in light-duty diesel vehicles. The successful commercialization of DPF technology has allowed combining attractive characteristics (good fuel economy, high low-end torque characteristics) of a diesel engine with significant PM emissions reductions to meet the stringent legislation.

The design for advanced filter systems is driven by the lifetime pressure drop requirements with the accumulation of non-combustible materials (ashes) over time in the filter. More compact filter designs can be achieved by using filters with the proprietary Asymmetric Cell Technology (ACT) providing a larger inlet channel volume and therefore a higher ash storage capacity in the same space envelope without compromising the filter bulk heat capacity and mechanical integrity. The current work on engine dynamometer demonstrates a 65% higher ash capacity to reach the same pressure drop threshold compared to the same volume filter with the standard cell design. This benefit can be utilized in different ways dependent on the application requirements, like lower lifetime pressure drop or longer service interval for the same size filter or a smaller filter volume with the same service interval. In combination with the robust DuraTrap® AT filter material, the ACT design has the potential to meet the soot load as well as lifetime pressure drop requirements in a very compact package of 75% of the standard filter at equal total soot load levels.