- Trays, packing,
- vapour holders,
- liquid traps,
- drain plugs,
- supporting frames,
- liquid distributor,
- vapour distributor etc,
Are some of the parts and accessories fitted inside of an industrial distillation column. The model below shows only an ideal set up which is not similar or identical to all types of distillation columns available in the manufacturing industry. However, we can study it to know what it actually has for conducting distillation operation on a large and small scale. Based on vapour –liquid equilibrium data of the mixture which may be in vapour or in the liquid phase. A distillation column equipment is designed to obtain the desired separation.
Without any calculations and equations, let’s know as the rule of thumb what does distillation column equipment contains in it. What does each item could help to obtain a distillation operation with illustration? Let’s imagine a binary mixture in liquid phase has two components. If they are required to be separated into the individual pure component. In case they have a vast difference in boiling points so that we put it in the vessel and heat it. So, that at a temperature where it meets one component boiling point. Then the liquid produce vapour and these vapours rise upward. Which in case of a column filled with the mixture at the bottom vessel. By supplying enough heat by means of steam the vapours will be generated and move in upward direction.
A series of plates are fitted from the bottom have perforated holes in them. Some have valves and bubble caps. The vapours penetrate through these holes and reach a feed plate. To this plate, we can supply continuous liquid mixture into the column. The liquid from feed plate due to gravity and density flow on to the down section of the tray. Pass through the trays and overflow into downcomer which acts as the channel between trays. Downcomer helps the liquid to stay on the tray for the desired duration.
Each plate if fitted on frame supports having a manhole section. Feed plate has a liquid distributor to spread the liquid evenly to avoid the condition of dryness. Above feed plate, liquid collector maintains the liquid continuous flow toward the bottom of the column from the top section. The vapour is condensed to liquid and a part of it is sent back to the column.To prevent other components having high boiling point value from carrying over to the top section. This section usually filled with packing than trays. Based on the packing material and packing types the mass transfer will be enhanced. Combination of packing and tray system improve the performance of a distillation column equipment. Above the packing, a liquid distributor is fitted to make the liquid flow all over the packing.
A model below shows a distillation column equipment. It is a combined system designed with packing and tray setup inside it. This design is an optimized for packed and tray column.
Distillation column equipment cross section diagram: