Distillation process of short-range molecular distiller

- Jun 25, 2019-

1. Molecules diffuse from the liquid phase body to the evaporation surface: Generally, the diffusion rate in the liquid phase is the main factor controlling the molecular distillation speed, so the thickness of the liquid layer should be reduced as much as possible and the flow of the liquid layer should be strengthened.
2. Free evaporation of molecules on the surface of the liquid layer: The evaporation rate increases with the increase of temperature, but the separation factor sometimes decreases with the increase of temperature, so it should be based on the thermal stability of the material to be processed. Choose an economically reasonable distillation temperature.
 3. Molecules fly from the evaporation surface to the condensation surface: During the process of vapor molecules evaporating from the evaporation surface to the condensation surface, they may collide with each other or may collide with air molecules remaining between the two sides. Since the evaporation molecules are much heavier than the air molecules and mostly have the same direction of motion, their own collisions have little effect on the direction of flight and the rate of evaporation. The residual gas molecules have a chaotic thermal motion between the two sides, so the number of residual gas molecules is the main factor affecting the direction of flight and the evaporation rate.
4. Condensation of molecules on the condensation surface: As long as there is sufficient temperature difference between the hot and cold sides (generally 70~100 °C), the form of the condensation surface is reasonable and smooth, the condensation step can be completed in an instant, so choose a reasonable short-range molecule. The form of the distiller is quite important.