MIXER DESIGN OPTIMIZATION FOR HIGH SOLIDS CONTENTS MEDIA : METHODOLOGY AND APPLICATION TO THE PECHINEY'S HIGH DENSITY PREDESILICATION PROCESS

摘要

The most obvious aim of a mixer in slurries exhibiting high solids concentrations is to prevent solids from settling at the bottom of the tank. Nevertheless, depending on process requirements, the mixer may also be able to keep the solids concentration homogeneous all over the height of the tank, to prevent short-circuits in the tank, to facilitate the slurry transfer from one tank to another in case of continuous processes, to achieve sufficient heat transfer performances. The list is quite long. This paper points out the important parameters to take into account for the mixer design and presents a methodology for defining an optimized mixing system for high solid contents slurries. An application of this method to PECHlNEY's high density predesilication process will be described for process capacities up to 1000 m~3.