Like in a channel type recuperator, the heat transfer is done, in a heat exchanger, by convection.
These equipment have a more compact design that provides a quick and easy erection.
In a heat exchanger, the tubes bundle is built in the frame containing it. In order to avoid possible cracks that may result from different thermal expansions between the tubes bundle and the frame, some compensators are installed or some tubes of the bundle are bent.
These equipment are suitable for the following cases:
- When the flue-gases temperature is not too high, around 700 - 750 oC., except for special cases.
- When a channel is not available for the tubes bundle to be introduced into.
Range of application of these heat exchangers is really wide, being especially suitable in plants for solvent incineration in the automobile industry, in co-generation plants, in metallic and plastic surfaces treatment plants, etc.
Three steps heat exchanger at counterflow