What is the principle of normal operation of a horizontal thin film evaporator?

The working principle of horizontal thin film evaporator:
    The material enters the evaporator from the upper feed port and is then ejected by the rotating liquid distributor, so as to be evenly distributed over the inner wall surface of the cylinder, and then driven by the scraper to form a uniformly dispersed liquid film on the inner wall of the evaporating cylinder heating. . The liquid film absorbs the heat transferred from the heating medium to the evaporation surface (the inner wall of the cylinder), so that the material is quickly evaporated, so that the material is separated, purified, concentrated, etc., and when the scraper of the inner wall of the cylinder rotates, the material is pushed thereon. A fluid bow wave (also called a vortex) is formed, and the fluid in the arcuate wave flows downward in a spiral shape because the squeegee has an angled groove. The drag vortex is formed behind the scraper to improve the heating efficiency, and due to the action of gravity, the material sticks to the wall surface and flows vertically downwards to form a thin film flow. Due to the rotation and agitation of the squeegee, the arcuate wave is continuously exchanged with the film flow for material and energy, which facilitates evaporation of the material on the heat transfer surface, so the agitated film evaporator can handle heat sensitive and highly viscous materials. At any point in the cylinder, the material flow rate consists of two parts; it is caused by the stirring blade pushing action and the gravity of the liquid film itself. These two effects make the residence time of the object on the heating surface very short. For highly viscous fluids, the squeegee push is the primary role of fluid downwards.