Drying process involving three phases: gas, liquid and solid, and numerous types of process equipment (dryers) is a complex and difficult to model operation of chemical engineering. Vast literature on simulation and design of various drying processes shows multitude of process and equipment specific computation routines that have been developed. Each of them is dryer specific and took a lot of time to construct from scratch. It is therefore highly desirable to identify as many as possible building blocks of which any drying process can be built. Combining them with reliable databases that can be shared by all of these routines will enable to rapidly simulate numerous drying processes within a single computer code. Such approach is not yet available in commercial process simulators. This approach is used in the computer code dryPAK. It is especially suitable for using as a teaching tool with which steps of model building can be clearly explained and illustrated. With rising computer speed and memory it is probably possible to construct a single simulation and design tool for most of the drying processes based on the dryPAK structure.