Modelagem e simulação fluidodinâmica de um secador de leito fluidizado industrial.

Abstract

The fluidized bed dryers are used during production process of resins of Polyvinyl Chloride (PVC) and they represent equipments with great energy consumption in the steam form. Two aspects can be approached with view of the improvement of the dry process. The first consists of the optimization of the energy consumption through the use of a feed forward anticipatory control capable to guarantee that variations in the mass flow rate and in the text of humidity of humid PVC for the dryer, don't promote the elevation of the humidity text in dry PVC above the maximum limit of specification. The second is related to the fluid dynamic optimization of the process through the determination of the conditions that avoid the formation of gathering of solids inside the equipment. This work had for objectives the definition and elaboration of a dry model for PVC in the software commercial VISUAL FORTRAN, that facilitates its future use in the control of this operation, as well as the obtaining of the patterns of flow of the gas phases and solid inside the dryer using the software CFX-3D. Data of the literature and of the process were used for verification of the kinetic model. This model has foreseen in a satisfactory way the experimental data and it was shown appropriate for use in control. The profiles flow obtained by the fluidynamic model used presented current limitations mainly of considerations accomplished for definition of the geometry of the dryer.