عنوان مقاله [English]
Nowadays, most chemical and food products are offered in powder or granular form, such as detergent powders, and, for this, factories use a spray dryer tower in their processes. For spray drying, a hot gas contacts with droplets and, during this contact, momentum, heat and mass transfer are carried out simultaneously. In this simulation, a model has been presented to predict operational conditions, including drying time and the height of the tower and the effect of various parameters has been studied. For this purpose, equations of momentum, heat and mass balance have been derived and dimensionless numbers and heat and mass transfer coefficients are calculated. Then, all the equations are composed in a computer spreadsheet program. For solving the driven differential equations, a time step was considered and solved using a finite-difference method. The model was verified using industrial data and good agreement between them was achieved. The results of this simulation are useful for new dryer designs, the optimization of existing units and for evaluation of the changes in their operating conditions.