Detailed introduction
　　I. Summary of Rising Film Evaporator
　　The composition of the riser evaporator is that the liquid enters the heating tube to heat according to the principle of siphon pump, and separates the liquid from the steam after flowing into the separator. The liquid flows back to the evaporator through the circulating pipe, forming a closed-circuit cycle. Therefore, this kind of evaporator is also called an external-circulation evaporator. The heating tube is composed of heat exchanger tubes. After the raw material liquid reaches the boiling point or approaches the boiling point, it is introduced from the bottom of the heating chamber. It is driven by the high-speed rising secondary steam and evaporates along the inner wall of the heat exchanger tube. The required concentration can be reached at the top of the heating chamber. The liquid is discharged from the bottom of the separation chamber. The secondary steam generated is removed by the upper separation plate group after the bubbles, water beads and impurities are removed. Become the next effective heat source. The rising film evaporator is suitable for the solution with large evaporation, thermal sensitivity, low viscosity and easy foaming, but not for the solution with high viscosity, crystal precipitation and easy scaling. Rising film evaporator is suitable for evaporation of large evaporation volume, heat sensitive, sticky and foaming substances. It can be used as a high concentration device because of its short residence time in one-way operation.
　　2. Main characteristics of rising film evaporator:
　　1. High turbulence of liquid - moving upward in order to get rid of gravity, so riser evaporator is also suitable for products with high viscosity and scaling on heating surface.
　　2. Stable and efficient operation - based on product cycle under broad conditions.
　　3. Material enters the heating pipe evenly through the bottom of the evaporator, is heated by steam outside the tube, boils in the tank and vaporizes rapidly. In the middle of the heating pipe, a steam column is formed. The steam density decreases sharply, the steam rises at a high speed in the tube, and the material liquid is driven by the rising steam, which rises rapidly along the tube wall and continues to evaporate. The gas-liquid two phases are in the gas-liquid separator. Separate and concentrate the material. If the material concentration is insufficient after one evaporation, the material outlet can be connected with the heater inlet in parallel, and part of the reflux can be carried out until the material concentration is up to standard. Normal pressure or vacuum operation can be used in operation.