kth_logo.gif

Article

A numerical and analytical hydrodynamic two-phase study of an industrial gas-lift chlorate reactor.

Authors: Wedin, R., Dahlkild, A. A.
Document Type: Article
Pubstate: Published
Journal: Computational technologies for fluid/thermal/structural/chemical systems with industrial applications
Volume: 1   125-136
Year: 1999

Abstract

The aim of the present work is to set up a CFD-model and simulate the two-phase flow in a conceptual industrial gas-lift chlorate reactor, in which sodium chlorate is produced with hydrogen gas as a by-product. Such a model enables a convenient way to test the simulated performance for various flow-regimes and geometries. A hydrodynamic two-fluid model is used, giving one solution field for each phase separately, with the transported quantities interacting via inter-phase transfer terms in the momentum equation. The simulated flow is steady, two-dimensional, incompressible, isothermal and turbulent. The gas phase is assumed monodisperse, while the liquid phase is taken to be continuous. Simulations are made with varying rates of hydrogen production using a set of various geometries, including cases of up- and down-scaling. As a complement, an analytical 1D-model which takes pressure drop in the electrode-package into account is developed to describe the electrolyte-flux through the cell. Remaining losses in the geometry are included in the model by means of a constant loss coefficient. Typical results include efficiency studies for different current densities, geometrical scalings and the influence of cell design. The importance of good design is shown to be different in different zones of the cell.