The full name is a surface cooler with copper or stainless steel tubes wrapped around metal fins (or rolled aluminum fins). The principle is to let the heat medium or cold medium or refrigeration working medium flow through the inner cavity of the metal pipe, and the gas to be processed flows through the outer wall of the metal pipe for heat exchange to achieve the purpose of heating or cooling the gas. The purpose of winding the fins is to increase the heat exchange area and improve the heat exchange effect. It is necessary to select suitable materials according to the working conditions.