A heat exchanger is a device in which heat energy transfer is carried out between two heat carriers with different temperatures. Gas, vapor, or liquid can be used as heat transfer media.
As of today, shell and tube heat exchangers are the most widely used type of heat exchangers. According to the principle of operation, heat exchangers are divided into recuperative, regenerative and mixing (cooling towers, scrubbers, mixing condencers, etc.)
Operating principle of a shell and tube heat exchanger is based on moving of hot and cold heat carriers through two different channels. The process of heat exchange occurs between the walls of these channels.
Shell and tube heat exchangers are classified as recuperative. Heat exchanges are divided into types depending on the flow direction of the heat carrier, and can be:
• counter flow;
• straight flow.
Main elements of shell and tube heat exchangers are tube bundles, tube sheets, body (shell), covers, branch pipes.
Pipe ends are fastened in the tube sheets by means of flaring, welding and soldering.
Medium velocity depends on the number of tubes inside the casing. In its turn, the coefficient of heat transfer will depend on the medium velocity.
Shell and tube heat exchangers can be of the following types:
|Pressure||up to 550 bar|
|Temperature||up to 600 °C|
|Length||up to 18 m|
|Diameter||up to 3 m|
|Materials||carbon steel and its alloys, stainless steel, copper and its alloys, nickel alloys, titanium, aluminium|