Modeling and experimental analysis of the flow of soft spheres in viscous fluids: study of particle-particle and surface-particle collisions and particle-fluid interaction

Abstract

The need production of clean energy makes anaerobic fludized bed reactor an efficient technology in order to produce hydrogen from biomass found in wastewater, often discarded on industry processes. Among other factors, the anaerobic fludized bed reactor hydrodynamic behavior is directly associed to mechanical, physical and superficial characteristics of bioparticles used, as dissipated energy provided from collisions between them. Such aspects may influence the agitation process in fluidized beds and, therefore, should be considered in the design of such equipment. Considering this context, the present project consists in characterizing soft particles, similar to those used in the treatment of effluents, as to their elastic and surface properties, as well as to evaluate the influence of interstitial fluid on particle-particle and surface-particle collisions. Particles with properties similar to those of bioparticles will be synthesized from sodium alginate. Commercial spherical particles will also be used. The stages of the Project include particle-particle and particle-wall collisions by means of coefficient of restitution using a pendulum-type equipment. In addition, computational fluid dynamics tools using the Discrete Element Method for particle modeling will be used to simulate the effect of collisions on viscous fluids. Experimental and numerical data will be compared in order to verify the validity of the existing models for particles with different mechanical and superficial properties. (AU)