When the liquid mixture flows along the heating plate and is heated, the light and heavy molecules escape the liquid surface and enter the gas phase, because the free path of the light and heavy molecules is different, so that the molecules of different substances move away from the liquid surface. At the same time, if a condensation plate can be set, it will make the light molecule reach the condensation plate is discharged, and the heavy molecule does not reach the condensation plate along the mixed liquid discharge, and then achieve the purpose of material separation.
The above is the molecular distillation, because the liquid mixture in the boiling film and condensation between the pressure difference is the driving force of the steam flow, so for a small pressure drop will cause the flow of steam. In order to ensure the realization of molecular distillation technology, it is necessary to run a very short distance between the boiling surface and the condensation surface, which is the reason for the short range distillation to be used in molecular distillation.
In practical industrial applications, molecular distillation has obvious advantages over conventional distillation technology, the first is a wide range of objects, which can be separated from high boiling point, thermal sensitivity and easy oxide; Secondly, because molecular distillation is operated at very low temperature and has a short heating time, it can effectively remove the low molecular substance in the liquid. The solution of liquid dissolution after solvent extraction was solved.
In addition, molecular distillation can selectively evaporate the target product and remove other impurities. Because it can separate more than two kinds of substances at the same time through multistage separation, and well protect the separated matter from pollution and invasion.