The invention relates to a drying device for drying a product comprising: a housing having a drying chamber, a product inlet at a first end and an product outlet at a second end; a drying rotor arranged rotatable within the drying chamber and having at least one helical groove at the outer surface thereof; a screw having a flight with a flight channel there between and arranged rotatable within the drying chamber and substantially parallel to the drying rotor; a driving mechanism configured for driving the screw in rotation around a screw axis; and a heater for providing thermal energy to the drying chamber, wherein the drying rotor and/or the screw at least are configured for moving the product from the first end to the second end, and such that the flight of the screw engages into the at least one helical groove of the drying rotor.