The process vessel use heat, pressure and/or vacuum to change a product condition and are mainly used for hydrolysis, neutralization, crystallization, distillation evaporation and storage in food, medicine, and chemical industries.
Reactors are used for a variety of process operations such as solids dissolution, product mixing, chemical reactions, batch distillation, crystallization, liquid/liquid extraction and polymerization. In some cases, they are not referred to as reactors but have a name which reflects the role they perform (such as crystallizer, or bioreactor).
They are usually fabricated in steel, stainless steel, glass-lined steel, glass or exotic alloy. Liquids and solids are usually charged via connections in the top cover of the reactor. Vapors and gases also discharge through connections in the top. Liquids are usually discharged out of the bottom.
Within the chemical and pharmaceutical industries, external cooling jackets are generally preferred as they make the vessel easier to clean.