After the damp raw material is put into the drier,the raw material will be distributed in the drier uniformly through uniform distributed stirring-up rake inside the drier and contact with countercurrent not air fully.It speeds up heat and mass transfer.During the period of dry,the raw material is affected by stirring-up rake with gradient and hot air,it can be moved and passed through th e dry region and reached to star valve and then discharge the finished product.