Biomass drying in a vibrating fluidized bed dryer with a Lagrangian-Eulerian approach

Abstract

The objective of this study is drying analysis of biomass in a vibrating fluidized bed dryer with employing a DEM-CFD simulation tool as a multi-physics and multi-scale platform. In this approach, the particles are resolved as discrete elements coupled via heat, mass and momentum transfer to the surrounding gas phase leading to Lagrangian-Eulerian coupling approach. This tool predicts the motion of particles as discrete elements based on the Newtonian equations of motion; and the thermodynamic state of each particle is extended according to the related algorithms. The thermodynamic state stands for estimating the temperature and species distributions through the particle due to external heat sources and chemical reactions. The required experiments are carried out in the industrial-scale vibrating grate dryer. The intention of experimental works is estimating the moisture content, density and size distribution of materials as well as residence time to evaluate the simulation results. The aim is optimizing the operation and efficiency of vibrating fluidized bed dryer by investigating the influence of effective parameters as temperature and velocity of inlet gas, initial dryer temperature, initial moisture content of particles and grate intensity on drying process. At the end, the effect of size distribution is shown by temperature distribution of particles during interaction with the superheated steam in the system.