NUMERICAL ANALYSIS OF MULTIPHASE SOLID-GAS FLOW WITH EULERIAN MODELS AND KINETIC THEORY CLOSURE

VENIER CESAR; MARQUEZ DAMIAN, SANTIAGO; RAMAJO DAMIAN; NIGRO NORBERTO

Mendoza

Congreso; ENIEF 2013; 2013

AMCA

Multiphase solid-gas flows may be found in many industrial applications, from oil refiningprocesses to hydrogen production reactors. In particular, we focus our interest in the dynamics of solidparticles in a circulating fluidized bed riser of a Fluid Catalytic Cracking (FCC) unit, in which the solidparticles distribution is one of the main variables in the global efficiency of the unit. In the last decades,much effort has been put in the development of Euler-Euler models with granular energy coupling tosimulate this kind of problems due to the good balance between computational cost and accuracy of thenumerical solution. In this work, in order to have a closure with the Navier-Stokes equations for the solidphase, we use the kinetic theory of granular flow with solid pressure and stress tensor models, whileWen-Yu and Ergun correlations are used to calculate the drag coefficients. All the numerical simulationsare carried out with the fully unstructured open source code OpenFOAM R , based on the finite volumemethod. In addition, an iterative procedure based on a combination of PISO and SIMPLE method (calledPIMPLE) is adopted and a proper discussion of its benefits is performed. To validate the solver, wepresent two widely studied multiphase flow problems. The first one consists on a sedimentation columnstarting from a uniform solid volume fraction suspension. The second one is based on a falling block ofsolid particles in a pure gas environment. Finally, we study a problem of a fluidized bed of particles witha constant gas injection from below. For this case, we are able to verify the good performance of thesolver. In order to do this, we analyze the time and space average profiles of the solid volume fraction incomparison with the numerical and experimental results from several authors.