A spray drying apparatus is a drying apparatus that directly dries a solution or suspension into solid particles. The dry product can be directly obtained from the liquid, eliminating the unit operations such as evaporation, crystallization, separation and pulverization, and can be continuously and automatically produced, and the operation is stable. With this drying method, the gas-solid two-phase contact surface area in the spray drying device is large, the drying time is short, and the drying time is generally 5 to 30 s, which is suitable for drying the heat sensitive material. The product obtained by drying is of good quality, and particles of 30 to 50 μm can be obtained, and the product has good fluidity and fast solubility. The disadvantage is that the dryer has a large volume and a low heat transfer coefficient, resulting in low thermal efficiency and high power consumption. There are many classification methods for spray drying equipment. According to the flow direction of gas and liquid, it can be divided into parallel flow, counter flow and mixed flow; according to the installation method of atomizer, it can be divided into upper spray type and lower spray type; The structure of the device can be divided into centrifugal type, pressure type and air flow type; according to whether the heating gas is circulated, it can be divided into open type, partial circulation type and closed type. Basic work flow of spray drying equipment (closed) The liquid is atomized by the atomizer and dispersed into fine mist droplets into the drying chamber. At the same time, the heating gas is sent to the heater through the blower to heat up, and then enters the drying chamber. The liquid droplets are thoroughly mixed and contacted with the hot gas in the drying chamber. The liquid in the droplets evaporates instantaneously into a gas, which is dried into fine particles. The mixed gas-solid two-phase is sucked into the cyclone by the induced draft fan, the two phases are separated, the solid material is settled to the bottom collector, and the gas phase is led to the dust filter to capture the escaped material. After the filtered gas phase is condensed by the condenser, the solvent carried in the gas phase becomes a liquid, which can be collected and used, and the gas as a carrier is dried and then recycled in the system. The reasonable application of the drying technology of spray drying equipment can bring us great benefits.