Distillation Column

Distillation columns allow the separation of a mixture of liquids based on the difference in their volatilities. There are two types of distillation processes. The type of distillation process will greatly influence the design of the pressure vessel:

1) Flash distillation involves heating a highly pressurized liquid mixture stream followed by separation of the vaporization of the more volatile component inside a flash chamber. The heated mixture first passes through a valve, and the pressure drop across the valve will result in the partial vaporization of the fluid. The vapor will be collected in the overhead of the flash chamber, while the liquid will settle at the bottom.

3) In column distillation or fractional distillation, one or more liquid mixture streams enters in the column at one or more points. As liquid stream flows down the column through the holes of the column internals, it comes in contact with the rising vapor coming from the bottom of the column. The column internals such as trays, plates, and packings provide the surface for mass transfer between the liquid and the vapor phases. The height of the column vessel depends on the number of trays or height of packings contained inside the vessel.