What is evaporation?

    Evaporation is the passage from the liquid to the gaseous state that only impacts the surface of the liquid. On the other end, if boiling temperature (different for each specific liquid and pressure connected) is exceeded, the constancy of the temperature and pressure parameters let the boiling process happen. Both processes fall under the name of vaporization.

    There are usually three purpose of evaporation operations in chemical production :

    ①  a concentrated solution is obtained directly as a chemical product or semi-finished product.

    ②  the solvent is removed by evaporation, the solution is concentrated to saturation, followed by cooling, the solid porducts is precipitated, that is, the combined operation of evaporation and crystallization is adopted to obtain a solid solute.

    ③ solute is removed and pure solvent is obtained.  

    Evaporation operations can be carried out continuously or intermittently, and the evaporation of large quantities of materials in industry is usually a continuous process in a fixed state.