Application of Mathematical Models Using Volumetric Transfer Coefficients in Fluidized Bed Dryers

Abstract

Fluidized bed dryers are often used in several industrial processes to dry wet granular solids with high moisture contents. During the drying process, simultaneous heat- and mass transfer occurs between the material and drying gas. Drying is an extremely energy intensive process, therefore the invested energy should be mitigated during planning the operation, granting optimal geometric and operational parameters of the device. During the planning, sufficiently accurate thermal models provide an opportunity to increase the effectiveness of dryers. The purpose of our work is to develop mathematical model to investigate the influence of operating parameters describing the simultaneous heat- and mass transfer in a fluidized bed dryer. The input parameters of the model are the volumetric transfer coefficients between the drying gas and the granules, due the uncertain heat- and mass transfer surface. A pilot plant fluidized bed dryer device is developed to determine the volumetric transfer coefficients and to study the heat- and mass transfer phenomena during the drying processes. The goal of our work is to model the fluidized bed drying process more accurately using volumetric transfer coefficients.