Numerical study on the gas fluidisation of secondary agglomerates of nanoparticles

Numerical simulations are performed on the gas fluidization of the secondary agglomerates of SiO₂ and SiC nanoparticles. An Eulerian two-fluid approach is used, which models the solids stress modulus with an empirical Jung-Gidaspow relationship and the drag force based on the secondary agglomerates. The results show the behaviour of particulate fluidisation of the secondary agglomerates of nanoparticles. The fluidised bed has a very high expansion ratio but without distinct bubbles. A three-zone distribution of time-averaged particle concentration is observed along the bed height. These are a dense zone in the lower part of the bed, a dilute zone at the top part, and a transitional zone in between. The radial distribution of particle concentration is found to be nearly homogeneous in both the dilute and transitional zones. The modelling results are compared with experimental results reported in the literature and a reasonably good agreement has been achieved.