The distillation equipment is a distillation method operated under high vacuum. At this time, the average free path of steam molecules is greater than the distance between the evaporation surface and the condensation surface. Therefore, the difference in the evaporation rate of each component in the feed liquid can be used to separate the liquid mixture.
The distillation equipment has requirements for the working environment. For example, the raw liquid in the distillation equipment will have some different thermal conditions. Due to the influence of different feed heat conditions, the amount of steam rising from the feed plate and the amount of liquid falling change, that is, the amount of steam rising to the distillation section and the amount of liquid falling to the stripping section change. The distillation equipment qualitatively represents the molar flow relationship between the steam rising from the feed plate and the liquid falling from the plate under different feed heat conditions.
In actual production, the raw liquid added into the distillation equipment will have some different thermal conditions:
1. Superheated steam with temperature higher than dew point;
2. Cold liquid with temperature lower than bubble point;
3. Saturated liquid below bubble point;
4. Gas liquid mixture with temperature between bubble point and dew point;
5. A cold liquid whose temperature is below the bubble point.
