Abstract
In gas-solid interaction, particle characteristics such as shape, size and density, interacting simultaneously, have a strong influence on the terminal velocity. The behaviour of fluid-dynamics systems acquires great uncertainty when the bed is composed by irregular particles, such as biomasses. Biomass, usually with a wide particle size distribution, is characterized by analyses that do not consider the irregular shape of the particles. Thus, these parameters are introduced in the different theoretical correlations, empirical or combinations of both to represent the biomass behaviour. However, the results obtained in the modelling are generally not satisfactory, because they provide results with considerable deviations. This work aims to compare the drag velocity measured experimentally in biomass (bagasse and straw) with the estimates found through correlations for the determination of the terminal velocity of spherical and non-spherical particles and sieving opening. It was developed appropriated and flexible system to this separation, the superficial air velocity can be regulated to the expected conditions. The material was separated at different air velocities and analysed by known methods for material characterization. The use of elutriation and sedimentation could contribute to the understanding the granulometric and morphological separation of biomass, obtaining separate fractions with homogeneity of size and shape in each fraction obtained, which are not satisfactorily predicted by the correlations used for the design of the fluidized systems for energy generation from biomasses.
