PNEUMATIC DRYING IN DILUTED PHASE - PARAMETRIC ANALYSIS OF TUBE DIAMETER AND MEAN PARTICLE DIAMETER

In previous work on pneumatic drying presented by the authors, a mathe matical model based on the conservation equations of momentum, mass an d energy was proposed. This model was developed taking into account ax ial and radial profiles for gas and solids velocities, pressure and po rosity in the drying tube. These dynamic profiles influenced the behav ior of temperature in the gas and particulate phases, gas humidity and solids moisture content. In this work, this model has been used to pe rform a parametric analysis of the tube and particle diameters in the pneumatic drying process. These variables were analyzed here for fixed conditions of gas and solids flowrates and initial values of temperat ures, humidity and moisture content. Factorial planning was applied to the numerical solution of the mathematical model. Experimental data o btained in a pilot scale pneumatic dryer were used as the initial cond itions in the simulation to specify the levels of the variables analyz ed. Results on the influence of tube diameter and particle diameter on the drying process were obtained by statistical analysis of the respo nses generated by the factorial planning.