A Kettle Reboiler Type Heat Exchanger is a special type of shell and tube heat exchanger widely used in refineries, chemical plants, petrochemical industries, and process plants. It is mainly used to vaporize liquid at the bottom of a distillation column to support the separation process. https://www.finfancooler.com/Heat-Exchanger/Kettle-Reboiler-Type-Heat-exchanger/