Durability Studies of Trap Oxidizer Systems

Trap oxidizer systems for the filtration and oxidation of diesel exhaust particulate have been built and tested for a number of heavy-duty diesel applications. System design has been focused on electrically heated bypassed regeneration using wall flow monolith filters, and microprocessor based control for real time determination of particle mass on the trap. The durability of such systems has been demonstrated in the laboratory, in the engine test cell, and on vehicle applications. An accelerated durability test bench was developed for the purpose of assessing the system's (and especially the ceramic core's) ability to withstand a lifetime of thermal regeneration cycles. The results confirm previous projections regarding ceramic core life. A complete trap oxidizer system was manufactured and installed on a generator set test cell designed specifically to expose trap oxidizer systems to actual exhaust conditions for long term durability studies. Test results to date indicate that the systems have the durability to perform in diesel exhaust streams for a lifetime of operation. A number of systems have been installed on vehicles to address the environment of vibration, shock, and transient operation spectra. Field tests will supply the data necessary to support the claim that trap oxidizer systems are a viable technology.