The drying equipment of Changzhou Fengri Powder Equipment Co., Ltd. needs to complete the transfer of heat and mass (moisture) at the same time during the drying process to ensure that the moisture partial pressure (concentration) of the surface moisture of the material is higher than that of the external space To ensure that the temperature of the heat source is higher than the temperature of the material. The heat is transferred to the wet material from the high-temperature heat source in various ways, so that the moisture on the surface of the material vaporizes and escapes to the external space, so that the difference in moisture content occurs on the surface and inside of the material. The internal moisture content diffuses and vaporizes to the surface, which continuously reduces the moisture content of the material and gradually completes the overall drying of the material.