Abstract: An apparatus for preheating and drying a granulate (43) comprises an inlet (61), a discharge (3a, 3b), a blower (10), air guide pipes (9, 15, 16, 19, 23, 24, 25, 31), a valve (11), and a heater. For creating three air circuits, an adjustable, multiport valve and a reversible blower (10) are provided. In each position, air from the blower passes in two directions through said multiport valve (11). The apparatus comprises a heat accumulator (161). The first circuit dries the granulate (43), the second circuit regenerates a humidity adsorbing material, and the third circuit transports material to the drier. The accumulator (161) preheats air during the regeneration, re-uses accumulated heat from said regeneration during the granulate drying cycle. The multiport valve is adjustable to various positions, gas in each position being directed along two paths through the valve.