Jacketed vessel
In chemical engineering, a jacketed vessel is a container that is designed for controlling temperature of its contents, by using a cooling or heating "jacket" around the vessel through which a cooling or heating fluid is circulated.
A jacket is a cavity external to the vessel that permits the uniform exchange of heat between the fluid circulating in it and the walls of the vessel. There are several types of jackets, depending on the design:[1]
Jackets can be applied to the entire surface of a vessel or just a portion of it. For a vertical vessel, the top head is typically left unjacketed. Jackets can be divided into zones, to divide the flow of the heating or cooling medium. Advantages include: ability to direct flow to certain portions of the jacket, such as only the bottom head when minimal heating or cooling is needed and the entire jacket when maximum heating or cooling is required; ability to provide a higher volume of flow overall (zones are piped in parallel) because the pressure drop through a zone is lower than if the entire jacket is a single zone.
Jacketed vessels can be employed as chemical reactors (to remove the elevated heat of reaction) or to reduce the viscosity of high viscous fluids (such as tar).
Agitation can be also used in jacketed vessels to improve the homogeneity of the fluid properties (such as temperature or concentration).