Thursday, November 12, 2015: 5:20 PM
252A/B (Salt Palace Convention Center)
Erosion is the mechanical wear in the walls of equipment by contact of particles carried in a gas or liquid flow. This phenomenal is a major problem in FCC units (fluid catalytic cracking), especially cyclones, reducing the lifetime of the equipment and causing unscheduled shutdowns, resulting in greater cost of maintenance and operation. The objective of this work is to analyze the erosion caused by the impact of FCC catalyst particles in cyclone optimized geometry, by conducting experimental studies combined with numerical simulation studies. The gas-solid flow was studied by means of Computational Fluid Dynamics (CFD) based on the averaged Navier-Stokes equations. The Eulerian approach was applied to continuous phase with RSM-SSG (Reynolds Stress Model) turbulence model and the particles trajectory was described by the Newton equations of motion (Lagrangian approach). The erosion rate is calculated from the knowledge of the impact angle of the particle on the wall, particle velocity during an impact, particle concentration and properties of the particle and the target material (particle density, Young’s modulus, Poisson’s modulus), and it was calculated by two different erosion models. In addition to the numerical simulations, physical experiments were carried out to validate the numerical results with different inlet velocities and mass rates. For physical experimentation, cyclones made of gypsum were constructed to accelerate the erosion process. Thus, it was possible to verify the most likely locations to the erosion in the applied geometry and calculate the erosion rates. The numerical results with the erosion models showed a qualitative good agreement with the experimental data, showing the same wall regions in the cyclone where erosion is more evident, and quantitatively in some cases. An experimental basis was constituted as a result of this work that will allow future studies of constitution and validation of models to predict erosion in cyclones.