Knitted Ceramic Fibers - A New Concept for Particulate Traps

Ceramic fibers with high specific surface area and adequate high-temperature strength are commercially available for filtration of diesel particulates and in-situ hot regeneration. The manufacturing of a deep bed filtration medium, using such brittle fibers, became possible after a special knitting technique was developed which forms the loops with minimum friction and pretension. Within this structure, the fibers are very little constrained and expose their active surface almost completely. Hence, high filtration efficiencies in the range of 95% could be demonstrated with favorable back-pressure characteristics. Blow-off phenomena were never observed.

Endurance testing on engines, with full-flow burner regeneration, proved the high robustness to mechanical and thermo-mechanical loading. This is one of the particular advantages of the new concept.

The concept has no inherent size limitations, can accommodate catalytic effects and offers a multitude of design parameters for application specific optimization.