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Cyclone separators are widely used in fluid catalytic cracking (FCC) units due to their lack of moving parts and relatively low-pressure drop. However, cyclone separators are prone to erosion-related issues, which is a major drawback. In this paper, a large eddy simulation (LES) of the particle-gas flow in a cyclone separator is investigated using a four-way Euler-Lagrange approach to model inter-particle collisions and the exchange of momentum between particles and fluid. The effects of inter-particle and particle-wall collisions are characterized in terms of erosive wear. Additional effects involving the exchange of momentum between the fluid and the particles are also discussed. The results show that considering the interparticle collisions between solid particles may be the key to predicting erosion.

Numerical simulations to predict erosion in cyclone separators due to the impact of particles were accomplished in this work. The predictions were performed through Computational Fluid Dynamics methods. The geometry investigated was similar to that of a second stage cyclone of a fluidized catalytic cracking unit. The numerical results were compared to experimental results available in the literature. The cyclone walls were made of acrylic with multiple coatings of drywall in the experiments. However, the implemented models to predict the erosion were developed for metallic materials. In this context, the validation was performed with cases in which the materials involved were the same as that used in the implemented models. The influence of the two-phase models, turbulence modelling, mesh resolution, dipleg presence and the models of particle/wall collision in erosion were evaluated after the validation. It was found that the turbulence modelling and mesh resolution were the most relevant factors in the erosion prediction, at least in the studied cases. Another relevant parameter is the friction factor, whose value significantly modifies the erosion rate. It was noticed that the interaction between the fluid and the particles reduces the erosion rate, even at low concentrations, as well as the interparticle collisions. Generally, the eroded regions were observed to match those from the experiments.