Classification of distillation processes

Distillation process is often used in pharmaceutical, petrochemical and other fields, such as vacuum distillation is a screw vacuum pump products in petrochemical, chemical and pharmaceutical fields, a major application direction, but distillation process also has many classifications.

Distillation is a kind of separation technology which uses the difference of boiling point of substance to separate and purify some mixed liquid or liquid-solid mixture by evaporation and condensation.there are many kinds and ways of distillation.

If carried out under different pressures, atmospheric distillation, vacuum distillation and pressurized distillation are carried out. The difference lies in the common vacuum distillation, which is not easy to volatilize or decompose at room temperature, and the pressurized distillation, which is mostly gas-liquid mixture or gaseous at room temperature.

According to the different process, batch distillation and continuous distillation can be divided into two parts. Intermittent distillation is often used in small-scale production or some special occasions, and industrial production of large quantities of materials, usually using continuous distillation.

The components of the mixture distilled according to need have two component distillation and multi component distillation. Generally, industrial production is multi component distillation.

Finally, according to the distillation process, it can be divided into equilibrium distillation, simple distillation and rectification. Balanced distillation is also called flash distillation. Like simple distillation, it is a single-stage distillation operation for mixtures that are easier to separate or less demanding to separate. However, the equilibrium distillation is a one-time vaporization (the material is put into the flash tank, the temperature and pressure remain unchanged, part of the rapid vaporization), and it is a continuous and stable process, suitable for large quantities of coarse separation occasions, can be continuous or intermittent; while the simple distillation is a gradual vaporization, there is a gradual heating vaporization process, often intermittent. Way.

Distillation is an advanced form of distillation, requiring multiple partial vaporization and condensation in a distillation column in order to obtain highly pure and almost complete separation. In order to realize distillation, not only the difference of boiling point between mixtures, but also the formation of temperature difference and concentration difference between gas and liquid in the distillation column should be satisfied. Distillation is also the most widely used distillation method in industrial production.

Although the distinction forms are various, the various distillation processes are actually integrated in practical applications. For example, in some vacuum vacuum distillation, it can be multi-component vacuum continuous distillation, or two-component intermittent simple distillation, production will be selected according to the specific characteristics of the mixture arrangement.