Molecular Distillation Unit

                                           Molecular Distillation Unit

1. Brief introduction :

Molecular distillation is a kind of special liquid-liquid separation equipment. Different from the traditional separation principle which relies on the difference of boiling point, molecular distillation realizes separation by the difference of mean free path of molecular motion of different substances. The liquid mixture flows along the inner wall of the main evaporator and is heated, and the light and heavy molecules escape from the liquid surface into the gas phase. Due to the different free paths of the light and heavy molecules, the light molecules reach the condensing tube and are discharged, while the heavy molecules cannot reach the condensing tube and are discharged along the mixed liquid, so as to achieve the purpose of material separation.

2. Working principle 

Molecular distillation is also called short path distillation. Under the condition of high vacuum, the liquid mixture flows along the heating plate and is heated. According to the difference of the molecular mean free path of different molecular weight substances, the size of the molecular mean free path between the vaporization surface and the condensation surface and the degree of evaporation are also significantly different. The molecular mean free path of light component molecules is large, while the average free path of the recombination component molecules is small, so that the light group can be achieved The condensation plate is condensed, so that it flows down the condensation plate, and the recombinant molecules can not reach the condensation plate and flow down the heating plate, so as to separate the different substances.

3. Advantage

1) short time - the material stays on the heating surface for a short time, reducing the chance of thermal decomposition.

2) low boiling point - the evaporation temperature is much lower than the boiling point of the material, so it further reduces the possibility of thermal decomposition of the material.

3) physical separation - can effectively protect the separated substances, suitable for the separation of high boiling point, heat sensitive and easily oxidized materials

4) low distillation temperature - lower than the boiling point, which is the essential difference with conventional distillation;

5) high vacuum - low pressure, can inhibit material oxidation damage.

6) Thin film of the distilled liquid - high heat transfer efficiency and uniformity

7) high degree of separation - no boiling bubble phenomenon, can effectively dissolve, deodorization, suitable for solvent extraction after liquid dissolving, selective evaporation of the target product, remove other impurities.

4. Application 

Molecular distillation is mainly used in the purification and separation of high boiling point, heat sensitive materials.

5. Component:

A complete set of molecular distillation equipment mainly includes: molecular evaporator, degassing system, feeding system, heating system, cooling vacuum system and control system. The core of a molecular distillation unit is the molecular evaporator。