Continuous Particle Size Distributions in a Bubbling Fluidized Bed Using Discrete Element Method

The focus of this paper is to study the behavior of systems with continuous particle size distributions over a gas-solid flow in a bubbling fluidized bed. A lognormal distribution with particle-size range between 800 micrometers and 900 micrometers was used to perform numerical simulations to investigate gas bubbles formation for a polydispersed system. Different drag models were used to predict the bubbles. Species segregation for a binary mixture and a monodispersed system were also studied. Discrete Element Method (DEM) simulations were performed using the source code MFIX (“Multiphase Flow with Interphase eXchanges”) [1] developed at NETL (“National Energy Technology Laboratory”). The bubble size of a single injected bubble depended strongly on gas-particle drag model used. The influence of the gas bubbles in the mixture and segregation was analyzed and discussed. The results were compared with experimental results from the literature and a good agreement were obtained.