Pure and safe products can be obtained by molecular distillation with simple operation process and less equipment. Molecular distillation technology can separate substances that are not easy to be separated by conventional distillation. The molecular distillation device must ensure that the system pressure reaches a high vacuum, has high requirements for material sealing, and the distance between the evaporating surface and the condensing surface should be moderate. The equipment processing is difficult and the cost is high.
The energy consumption of molecular distillation products is small. Due to the small overheat loss of the whole separation of molecular distillation, due to the unique structural form of the molecular distillation device, its internal pressure is very low and its internal resistance is far smaller than that of conventional distillation, which can greatly save energy consumption.
For the separation of high boiling point, heat sensitive and easily oxidized materials, molecular distillation provides the best separation method. Because molecular distillation operates at a temperature far below the boiling point of the material, and the residence time of the material is short.
The distilled liquid film of molecular distillation is thin, the heat transfer efficiency of the whole product is high, the heating time of the material is short, and the distance between the heated liquid surface and the condensing surface is less than the average free path of light molecules, so the light molecules escaping from the liquid surface almost reach the condensing surface without collision.
As the tower equipment mainly used for mass transfer process, it is necessary to make the gas-liquid two phases fully contact to obtain high mass transfer efficiency. In addition to meeting the process conditions, it should also meet the following basic requirements:
1. the production capacity should be large. That is, the material handling capacity per unit time on the section of the unit tower should be large. At a large gas-liquid flow rate, it is still unknown that a large number of phenomena such as mist entrainment, liquid blocking or flooding damage the normal operation.
2. high separation efficiency. That is, the gas and liquid phases can be fully contacted and the separation effect is good.
3. the operation is flexible. It has strong adaptability and wide operating range. It can adapt to different materials and maintain stable operation in case of load fluctuation, and still has high separation efficiency.
4. low pressure drop. That is, the resistance of fluid passing through is small, which can greatly save the power consumption of production and reduce the cost. If the pressure drop in the vacuum tower is too large, the system will be difficult to maintain the necessary vacuum.
5. simple structure, less consumables, easy to manufacture and install, which can reduce investment and cost.
6. it is corrosion-resistant, not easy to block, and convenient for operation, adjustment and maintenance.
