A scraped film evaporator is a device used to evaporate liquids and achieve efficient heat transfer in the process. Its working principle is mainly to use one or more rotating scrapers to form a thin film on the inner wall of the evaporator, and continuously remove the evaporated vapor from the liquid, so as to achieve evaporation. Principle and characteristics of scraped film evaporator:
Rotary Scraper: Scraper-type film evaporators are equipped with rotating scrapers inside, which are usually made of corrosion-resistant materials to accommodate solutions with different chemical properties. The scraper is in close contact with the inner wall of the evaporator during rotation, forming a thin film.
Film formation: Due to the rotational action of the scraper, the liquid entering the evaporator is drawn into a film, which forms on the inner wall of the evaporator and flows rapidly. This film is much thinner than a free-flowing liquid, so the surface area is increased, which helps to improve the efficiency of heat exchange.
Heat transfer: At the same time as the film is formed, the hot fluid (usually hot water or steam) in the evaporator comes into contact with the film, and the heat is transferred to the liquid through heat conduction and convection, so that it evaporates rapidly.
Steam Removal: The rotating scraper not only forms a thin film, but also mechanically removes the evaporated steam from the liquid, preventing the steam from re-condensing inside the evaporator, thus improving the evaporation efficiency.
Efficient heat transfer: Since both the thickness of the film and the velocity of the liquid flow are controlled by the scraper, efficient heat transfer can be achieved at lower temperatures, which helps to reduce energy consumption and improve the quality of the product.
The scraped film evaporator is suitable for the evaporation of liquids with high viscosity, easy scaling or containing solid particles, and has the advantages of high heat transfer coefficient, good evaporation efficiency, large operation flexibility and easy cleaning. Therefore, it has been widely used in chemical, food, pharmaceutical and other industries.
The scraper film evaporator commonly used in the experiment has the following specifications and classifications: the diameter of 60 80 100 150 200 is divided into stainless steel and glass The appropriate model can be selected according to the actual experimental environment.