WEAR RATE PREDICTION IN MULTI-SIZE PARTICULATE FLOW THROUGH IMPELLERS

A three-dimensional finite element formulation of multi-size particulate flow through a centrifugal impeller is presented. From the predicted flow field, the wear rate distribution along the impeller blades and shrouds is calculated using empirically determined impact and sliding wear coefficients. The computational domain consists of the three dimensional region enclosed between the two blades and the two shroud surfaces with upstream and downstream extensions. An Eulerian-Eulerian mixture model is used for the multi-size particulate flow, which consists of mixture continuity and momentum equations as well as the individual solids continuity and momentum equations. The effects of flow operating conditions on the wear rates are studied. A comparison of predicted wear rates from D50 or other mono-size simulations with multi-size particulate flow simulations shows that representing the slurry by a single particle size could result in substantial errors for different flow conditions.