Effect of Flow and Particle Behavior in De-NOx Catalyst on Degradation

Abstract

Effect of flow behavior in a honeycomb rectangular tube of a de-NOx catalyst on the adhesion of particles to the wall is studied in terms of a direct numerical simulation（DNS）. The results show that the adhesion of particles to the wall is strongly affected by the turbulent-laminar- transition flow behavior and is enhanced by the turbulence in the upstream region near the inlet. This agrees well with the previous experimental observation, in which the degradation of the catalyst appeared in the region near the inlet. The adhesion of particles is found to be enhanced not only by the stronger turbulence but also by the larger particles. In the downstream region, the adhesion on the wall near the rectangular edges is suppressed, since the turbulent-laminar transition progresses from these regions.