The process of a molecular distillation apparatus

Short-range stills are suitable for molecular distillation
.

The molecular flow flows from the heating surface directly to the condenser surface
.

The molecular distillation process can occur in the following four steps: the molecules diffuse
from the liquid phase body to the evaporation surface.

Usually, the diffusion rate in the liquid phase is the main factor controlling the distillation rate of molecules, so the thickness of the liquid layer should be reduced as much as possible and the flow
of the liquid layer should be strengthened.

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 the economically reasonable distillation temperature
should be selected on the premise of the thermal stability of the processed substance.

Molecules fly from the evaporation surface towards the condensation surface
.

As the vapor molecules fly from evaporation to the condensing surface, they may collide with each other or with
the air molecules that remain between the two sides.

Because evaporative molecules are much heavier than air molecules and mostly have the same direction of motion, their own collisions have little
effect on the direction of flight and evaporation velocity.

The residual gas molecules are in a disorderly state of 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.

Molecules are condensed on the condensing surface, as long as there is enough temperature difference between the hot and cold sides (generally 70 ~ 100 ° C), the form of the condensing surface is reasonable and smooth, and the condensation step can be completed in an instant, so it is important to choose the form of a reasonable condenser
.