The molecular distillation experimental device is equipped with multiple temperature measuring points, which can judge the position of the sensitive plate, judge whether the tower operation is stable, learn the operation essentials; learn the control and adjustment of the pressure and reflux ratio of the tower kettle, the alcohol content can be detected online; the raw materials can be heated and observed , Can realize the feeding of various feeding heat conditions; two observation cups are set continuously to observe the gas-liquid contact between the upper and lower plates of the analysis plate.

Molecular distillation supplies vapor-liquid two-phase contact for interphase mass transfer. The condenser at the top of the tower makes the vapor partially condensed, and part of the condensate is returned to the top of the tower as reflux, and the remaining distillate is the top product. The reboiler at the bottom of the tower vaporizes the liquid part, and the vapor rises up the tower, and the remaining liquid is used as the bottom product. The feed is added to the middle of the tower, the liquid in the feed and the liquid from the upper section of the tower descend together, and the vapor in the feed and the vapor from the lower section of the tower rise together.

In the entire molecular distillation experimental device, the vapor-liquid two phases are in countercurrent contact for mass transfer between phases. The volatile components in the liquid phase enter the vapor phase, and the hardly volatile components in the vapor phase transfer to the liquid phase. For systems that do not form azeotropes, as long as the design and operation are proper, the distillate will be a high-purity volatile component, and the bottom product will be a high-purity hard-volatile component.

The key to the complete separation of the liquid mixture lies in the application of reflux. The reflux includes both the liquid with high concentration of volatile components at the top of the tower and the vapor of the high concentration of non-volatile components at the bottom of the tower returning to the tower. The vapor-liquid reflux forms two phases of vapor-liquid contact in countercurrent, so that relatively pure single-component products are obtained at both ends of the tower.