The model uses mass and thermal balances ,psychrometric relations and sorption isotherms and scts partly as a black box model .A calibration must be carried out once, in order to tune the model to the specific dryer taking into account the heat losses of the installation and the deviation from equilibrium state between powder and outlet air .The srandard setup of this model is for a two-stage dryer (spray chamber and fluid bed dryer ),but it has also been adapted to other types of dryers e.g. containing an internal fluid bed .

DrySPEC2has successfully been implemented for the production of dairy products such as skim milk , wholed milk and whey permeate .The results obtained in increasing the earning capacity of industrialspray dryers are :up to 20% increase in capacity ,limiting the deviation in moicture content to lower than 0.05% (for example ,by adjusting the process to variations in the total solids content of the feed or moisture content of inlet air ) and an annual energy reduction potential of about 250000M³natural gas oer installation.