The use of heat exchangers for energy recovery in thermotechnical installations. Impiego degli scambiatori di calore per il recupero dell'energia negli impianti termotecnici.

After a general preliminary discussion of the meaning of "heat recovery" and possible systems for carrying it out, the author examines the possible different ways of transferring thermal energy from one fluid to another by means of an indirect heat exchanger. Air-to-air systems are in particular analyzed, examining the operating features of the various exchange types(rotating, fixed plate, multiple tower and finned tube exchangers). The paper concludes with a series of considerations on both energetic and economic aspects of thermal energy recovery.