Study of the dynamic in gas-solid systems by numerical simulation using particle and finite volume approaches

Abstract

The proposed work is part of a current research project, which the goal is to perform a theoretical study and develop numerical simulations involving dynamic in gas-solid systems. Gas-solid fluidized bed systems can be found in many operations in the chemical, biochemical, petroleum, pharmaceutical, agricultural, food, electronic, and power generation industries. Although the conversion rates of the catalytic reactors and thermal efficiency of energy facilities are directly influenced by the chemical reactions and the heat transfer processes, they are also highly influenced by hydrodynamic processes, which determine the spatial distribution of phases and species involved. As the hydrodynamic is prevalent in the processes of mass and energy transport in certain spatial and temporal scales, is essential to understand its characteristic and behavior. Even today the basic knowledge of the hydrodynamic processes that occur in multiphase flow in the industries is incomplete and insufficient. For that propose would be used the MFIX (Multiphase Flow with Interphase eXchanges) code developed at NETL (National energy Technology Laboratory, U. S. Department of Energy). The present study will analyzed the following results: fluidization curve with the determination of minimum fluidization velocity for particles of B group (Geldart, 1973); the profile of evolution of bubbles in bubbling fluidized beds with central jet; influence of vibration on fluidization, among others. Thus, using the code MFIX we intend to perform numerical simulations of the dynamics of fluidized beds using the techniques: (a) Lagrangian DEM (Discrete Element Method) based on particles and (b) Eulerian based in the discretization of the system in finite volume (two-fluid model for gas and "solid"). The results obtained with the code mfix will be compared with numerical and experimental data from literature and the results obtained with the theoretical study will be implemented in this code (mfix) for validation. (AU)