Falling film evaporator

working principle

The falling film evaporator is to add the feed liquid from the upper header of the heating chamber of the falling film evaporator, distribute it evenly to each heat exchange tube through the liquid distributor and film forming device, and flow from top to bottom in a uniform film shape under the action of gravity, vacuum induction and airflow. During the flow process, it is heated and vaporized by the shell side heating medium. The steam generated enters the separation chamber of the evaporator together with the liquid phase. After full separation, the secondary steam enters the condenser for condensation (single effect) or the next effect evaporator as the heating medium, so as to achieve multi effect operation. The liquid phase is discharged from the separation chamber. In the falling film evaporator, the materials to be evaporated enter from the top of the falling film evaporator through the feed pump and pass through the evaporation tube (tube side). The materials are uniformly distributed in the heat exchange tube in the form of film through the film distributor. Under the action of gravity, they fall in the form of film along the tube wall, and are heated by steam outside the tube. When they reach the evaporation temperature, they evaporate. The materials and secondary steam flow down the tube and evaporate in the form of film.

      Main features
● The pump has small flow, small installed power and low power consumption.
● Large concentration ratio, falling film evaporation, short concentration time, suitable for heat sensitive materials.
● Spray feeding at the top of the evaporator or use the multi overflow film distribution device to ensure that the feed liquid is evenly distributed in the film tube of the evaporator, forming a film shape, greatly improving the heat transfer coefficient, increasing the evaporation rate, and preventing the "dry wall" phenomenon.
● The feed liquid is separated at the bottom of the evaporator, and then enters the separator for further separation, which enhances the separation effect.
● The whole set of equipment has compact structure, small floor area and simple and smooth layout.