[ Hairpin-Type Heat Exchangers ]
The principle
Hairpin exchangers are jacketed ‘U’ tube exchangers operating in a true countercurrent flow, allowing also temperature cross (hot fluid outlet temperature is below cold fluid outlet temperature) with a very efficient design.
Another important feature of hairpin exchangers is the closure type, which allows the removal of the tube bundle and accommodate thermal expansion without requiring expansion or packed joints.
The configurations
Hairpin exchangers are available in two configurations: a single tube (Double-pipe) or multiple tubes (Multi-tube) within the shell.
- Double-pipe heat exchangers utilize a single pipe-within-a-pipe design and are commonly used for high fouling services, such as slurries where abrasive materials are present, and for smaller duties. Standard shell diameters range from 2” to 6”.
- Multi-tube heat exchangers are used for larger duties, with standard designs for shell diameters up to 30”.
Finned tubes, U-tubes, straight tubes (with rod-thru capability), fixed tubesheets and removable bundle are also options.
Advantages
- Process advantages: Hairpin units are preferable and more economic than TEMA-type for extreme temperature crossing, high pressure, low pressure drop, high temperature
- Operation and maintenance advantages: easy mechanical cleaning on the shell side thanks to the removable bundle
- Flexibility: Double Pipe Hairpin can accommodate streams flow rate or other conditions change. Unlimited numbers of sections can be re-arranged in parallel and series to fit new conditions