In the operating circuit of an industrial steam boiler, heat is "lost" in the combustion gases that leave the chimney and in blowdowns.
Thanks to evolution in designs, some boilers are equipped with circuits that can use the heat from these gases before it is finally emitted. The heat can be used either to heat the water entering the circuit, or to heat the air that the burner needs for combustion. The exhaust gases can be condensed, and achieve yields of 105% based on the lower calorific value.
These two applications are not alternatives to each other in boilers manufactured and installed by ATTSU, but are instead complementary and can be applied at the same time, and this technology has been applied to satisfy the need for fuel savings that customers demand.