The disc dryer is basically composed of a regular conduction dryer and a stirring device. A closed or semi closed drying working space is composed of a machine shell, and several hollow heating plates with slightly different diameters are horizontally arranged along the height direction inside, and heating medium is introduced into the plates. There are several mixing rakes on each layer of the disc, symmetrically installed on the central axis. The mixing rake is equipped with several rake blades along the axial direction, and the rake blade scraper is in floating contact with the disc surface. The rake blades on the upper and lower layers of the disc surface are in opposite directions. During operation, wet materials are continuously and evenly scattered by the feeder near the center of the first layer disk (small disk). The central drive shaft drives the mixing rake to rotate, and the rake blades spread the materials evenly on the disk while constantly flipping and pushing the materials, forming multiple concentric circular material rings. The cross-section of the material rings is an equilateral triangle, with the number equal to the number of rake blades, as shown in the figure below. Under the continuous pushing of each rake blade, the materials move outward along the spiral trajectory from the center of the disk to the outer edge of the second layer disk, that is, the outer edge of the large disk. The rake blades of the second layer disk move in the opposite direction, pushing the materials inward