Effective Thermal Dispersion in Two-Phase Reactors
by
A. Andonowati
Department of Mathematics, Institut Teknologi Bandung, Indonesia and Faculty of Mathematical Sciences, University of Twente, The Netherlands

Many chemical reactors such as an automobile catalytic converter and a packed bed reactor involve two distinct phases. In these examples, the heat released by chemical reaction often concentrates in a very localized regions known as hot-spots that can sinter the catalyst causing many undesirable effects. Except for very small systems, variation in the convection velocity of each phase can actually enhance the effective thermal dispersion known as Taylor dispersion. This improved thermal dispersion can actually avoid the formation of hot-spots. The estimation of the convection-enhanced effective dispersion often involves tedious moment or averaging analysis where the final estimate is in the form of infinite series. In this paper, a compact analysis is used to calculate the effective dispersion coefficient. Starting point is using Center Manifold Theory to obtain Taylor-Aris dispersion in an infinite series. Instead of finding the closed-form limit of this series by a direct method, an analysis of its dual problem is used leading to a compact and rather easy way to obtain the closed-form of the effective dispersion coefficient.

Date received: August 22, 1999

Copyright © 1999 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # cadl-06.