Detailed introduction
　　Summary of falling film evaporator
　　Evaporation is the operation of heating the solution in the concentrator to boiling, vaporizing and removing some solvents to increase the concentration of the solution. It is also a separation process between volatile solvents and non-volatile solvents in solution. The equipment used to realize evaporation operation is called evaporator or concentrator. Therefore, falling film evaporator, also known as falling film concentrator. Falling film evaporator is a kind of heat exchanger, in which the upper tube box of the heating chamber of the material-liquid self-falling film evaporator is added. Through liquid distribution and film-forming device, the falling film evaporator is evenly distributed to the heat exchanger tubes. Under the action of gravity and vacuum induction and air flow, it flows uniformly in a film form from top to bottom. In the process of flow, steam is heated and vaporized by shell-side heating medium. The steam and liquid are jointly entered into the separation chamber of the evaporator. The vapor and liquid are fully separated. The vapor enters the condenser condensation (single-effect operation) or the next-effect evaporator as heating medium, thus realizing multi-effect operation. The liquid phase is discharged from the separation chamber.
　　The main body of the equipment consists of heaters, separators, hot-press pumps, condensers, sterilizers, heat preservation pipes, material pumps, water pumps, drainage systems, distributor cylinders, operating tables, electrical instrument control cabinets, valves and pipes. Falling film evaporator has falling film double-effect evaporator, falling film three-effect evaporator and so on. It is suitable for low-temperature concentration of milk, glucose, starch, xylose and other food, chemical and environmental protection industries.
　　CHARACTERISTICS OF FALLING FILM EVAPORATOR
　　1) The material liquid of falling film evaporator is added from the top of the evaporator, and falls along the tube wall under the action of gravity. During this process, the evaporation is enriched, and the concentrated liquid is obtained at the bottom of the falling film evaporator. Falling film evaporator can evaporate materials with high concentration and high viscosity (for example, in the range of 0.05-0.45Ns/m2).
　　2) Because of the spraying feed at the top of the evaporator, the solution flows in a film-like flow in a one-way evaporator with uniform distribution and high heat transfer coefficient. Forced circulation makes the material with high viscosity easy to flow and evaporate, and the concentration ratio is high.
　　3) After gas-liquid separation at the bottom of the evaporator, the feed-liquid is re-separated into the separator to enhance the separation effect. The residence time is short and the material is not easy to deteriorate, so it is suitable for the treatment of heat-sensitive materials.
　　4) The liquid retention is small. Falling film evaporator can operate quickly according to the changes of energy supply, vacuum degree, feed volume and concentration. Near constant,
　　5) Low temperature differential evaporation can be used because process fluid flows only under gravity rather than driven by high temperature difference.
　　6) falling film evaporator is suitable for evaporating and concentrating foaming materials. As the material liquid evaporates in the heating tube, vapor liquid separation is formed, and at the bottom of the effective body, most of the liquid material is removed. Only a small amount of liquid and all two steam enters the separator to strengthen separation. The process of material and liquid has not formed too great impact, thus avoiding the formation of foam.
　　7) The equipment adopts vertical landing structure. The whole set of equipment is compact in design, occupies a small area and has a simple and smooth layout.
　　8) The equipment is equipped with CIP on-line cleaning, which can realize in-situ cleaning without dead corner.
　　9) Adopt advanced control methods. The concentration process mainly takes the effective temperature as the control parameter. The power supply, pumps, and control instruments are all concentrated on the operation box and control panel to realize automatic operation and production.