Experimental and CPFD study of gas–solid flow in a cold pilot calciner

Experimental characterization and computational fluid particle dynamics (CPFD) simulations of a cold pilot–scale cement calciner were carried out to investigate the dispersion and heating of cold cement raw meal particles in the hot gas flow. During the experiments, the gas velocity and temperature were measured at different locations upstream and downstream of the place where the particles were fed to the calciner. The simulations were carried out using Eulerian–Lagrangian approach together with the Multi–Phase Particle–In–Cell (MP–PIC) method, based on the commercially available Barracuda Virtual Reactor® 17.1.0 software. For the particle–free flow, it was shown that the grid–independent velocity profiles predicted from the simulations are in proper agreement with the measured values. For the particle–laden flow, the simulation results from two drag models of EMMS and Gidaspow were compared with the gas temperature measurements and visual observations. The simulation results from the Gidaspow model exhibited an over–prediction of the amount of falling particles to the upstream regions. Both drag models exhibited a local minimum temperature region at a location slightly different from the measured one in a cross–section close to the particle feed position. For the Gidaspow model, a second low gas temperature region was observed at the opposite position of the particle feed that was not detected by the measurements. Overall, it is concluded that the Barracuda Virtual Reactor® software is able to capture the particle dispersion and gas–solid interactions in the studied pilot–scale calciner and the EMMS drag model is more reliable for prediction of the gas–solid flow.