To dry wetting a powdery and granular material having high moisture content and adhesion efficiently by fixing the supply port of a heating air supply pipe in the tangential direction to the upper region of an inverted cone so that the wetting powdery and granular material being blown in are entrained and unaggregated.

The process comprises a drying chamber 5 including an inverted cone 4 coupled with the lower section of the tubular body 3 of a drying tower 1, a wetting powdery and granular material gas supply pipe 6 fixed vertically to the lower central section of the cone 4, a heating air supply pipe 7 fixed in the tangential directon to the upper region of the cone 4, and a discharge pipe 8 fixed in the tangential direction to the upper section of the drying chamber wherein an air supply fan 9 is disposed in the pipe 6. When the fan 9 is started, sucked outer air or circulation air is fed from the vertical supply port of the pipe 6 into the drying chamber 5 to produce an ascending current. The wetting powdery and granular material are unaggregated at the inverted cone by the axial ascending jet flow being blown from the pipe 6 and a swirling flow being blown from the pipe 7.