Modelling of binary fluidization of coal and ash and validation using radioactive particle tracking and densitometry

Abstract

Binary fluidization finds wide application in a variety of gas–solid catalytic and non‐catalytic industrial fluidization systems. In the present study, a three‐dimensional transient computational fluid dynamics (CFD) model was used to model the binary fluidization of coal and ash in a laboratory‐scale cold flow fluidized bed. In parallel, phase velocity measurements using radioactive particle tracking (RPT) and gamma‐ray densitometry were performed, which provided a rich database for validation of the CFD model. RPT being a time‐resolved Lagrangian technique, it was possible to extract velocity fluctuations and their correlations in addition to the mean velocity profiles. The latter provided additional validation for the CFD model, in addition to the typical validation that is done with time‐averaged profiles of phase velocity and volume fraction. The robust validation procedure opens up the possibility of expanding this model to a pilot plant‐scale fluidized bed.