2D GAS AND SOLIDS FLOW PREDICTION IN CIRCULATING FLUIDIZED-BEDS BASEDON SUCTION PROBE AND PRESSURE PROFILE MEASUREMENTS

A fluid-mechanical model for the recirculation zone of circulating flu idized bed (CFB) risers is presented which considers the local flow st ructure of the CFB to be composed of an upward flowing lean suspension and downward flowing strands or clusters of particles. The model para meters are obtained by fitting the model to at least one measured hori zontal profile of the upward and one downward solids fluxes and making use of a measured pressure profile along the riser height. The model allows the two-dimensional gas and solids flows inside the whole recir culation zone to be predicted. The model has been developed on the bas is of measurements in a pilot-scale CFB unit (riser height 15.6 m, 0.4 m diameter). The application of the model to large-scale CFB combusto rs of Chalmers University, Goteborg/Sweden and Stadtwerke Flensburg/Ge rmany illustrates its practical applicability.