Abstract: The apparatus consists of a hollow cylindrical case arranged at an angle to the horizontal axis of its rotation. Disposed in a space inside the case are coils each bent into a helix of suitable shape, arranged coaxially relative to other coils and connected to manifolds which are attached to an internal wall of the case, each with only one of its ends and are connected to a space between the walls of the case passing wherethrough is a heat carrier. The points where the coils are connected to the manifolds are separated from the internal wall of the case by a distance anywhere between 1/3 and 1/2 of the internal diameter of the case of the drier.