Many materials, including petroleum,heavy residue, chemical medicine, medicine and natural food, health care products, fatty acid and so on, are generally heat sensitive and viscous. Moreover, they also possess high boiling points. Separating these materials from their components and maintaining the quality of such products are only able to distillate at low boiling points or even lower than the boiling temperature.
When the operating vacuum is about 500 Pa, it is capable of conducting in the scratch film evaporator or falling film evaporator. However, if the distillation is operate under the high vacuum status( for instance, the pressure ranges from 0.001 to 100Pa), problems are bound to cause. Therefore, it is necessary to choose the evaporator which the vapor pressure id no less than pressure difference caused by heating and cooling surface, and the evaporator quipped with outside condenser is excluded from the distillation process under the high vacuum range.
In contrast, the short-path evaporator is quietly adaptable to this occasion, and the condenser should be placed within evaporator and opposite to heat distillation. Therefore, as a relatively new equipment which is not widely applied in industrial production, the short-path distillation is able to solve many tough issues that normal distillation technical cannot conquered.