Experimental and Theoretical Study of the Simultaneous Development of the Velocity and Concentration Profiles in the Entrance Region of a Monolithic Convertor

Abstract

In catalytic afterburning of waste gases the monolithic or active wall reactor is becoming increasingly important. Most experimental and theoretical studies on this reactor that have been published so far consider the velocity field in the separate channels of the monolith either undeveloped, i.e. plug flow (1-3), or fully developed, i.e. laminar flow (4-7). In reality, however, the velocity profile, which can be assumed to be more or less uniform at the entrance of the channel, will develop into a laminar Poiseuille profile downstream the tube. This implies that the experimental measured conversions will not correspond to the theoretically calculated concentration profiles for either plug flow or laminar flow, i.e. concentration profiles calculated for a uniform velocity profile will result in a conversion which is higher than the actual conversion, while a fully developed profile gives rise to a conversion lower than the actual one. Therefore, to get a more