Vessels are usually a type of pressure container that can be positioned either vertical or horizontal depending on space restriction. Some process may require the vessel to have internal components.
Columns are vertical vessels with multiple levels of internal trays or packings which act as a mass transfer device for the separation of liquids and vapours throughout the process.
Reactors are a type of vessel that contains a ‘catalyst or agitators’ which facilitate the process of changing the fluid or vapour that pass through the tubes. Depending on the operation, these units can be tall vertical vessels or some can be spherically shaped vessels.
Limited space required - The units are vertical in orientation.
Batch Reactors - A compact design allows multiple product range involving different reactants and can use the same equipment for the process.
Continuous Reactors - Can operate for a long period without shutdown. Product qualities are more consistent because the reaction criteria are better controlled. Produce less wastage resulting in a more efficient operation.
In the first place, the liquid mixture to be processed enters the equipment near the middle section onto a tray. The trays divide the process into an upper section (enriching) or a lower section (stripping). Then, the liquid flows down the equipment where it is collected and processed into a reboiler unit. Finally, the vapour from the reboiler is re-introduced back into the system. Occasionally, some liquid is recycled back to the top, to start the separation process again.
There are two main types of reactors– batch and continuous.
Batch reactors are mainly used where the reactants are mixed and often heated to start the reaction and then cooled. After the reaction has taken place, the reactor is cleaned ready for another batch of reactants.
Continuous reactors, as the name suggests, provide a continuous feed of the reactants into the reactor, allowing the reaction to take place with the outcome of the product withdraw at the other side. The reactants and the product flow rate must be equal throughout the process. The most common types of continuous reactors are tubular reactors, fixed bed reactors and stirred reactors.