Recuperative heating unit for industrial furnace

A recuperative heating unit for the firing of an industrial furnace, comprising:

• a burner assembly receivable in a furnace wall, said burner assembly including an inner tube terminating in a burner head, an intermediate tube coaxially surrounding said inner tube and forming therewith an air-supply duct, and an outer tube constituting a peripheral housing wall, said outer tube coaxially surrounding said intermediate tube and forming therewith a discharge duct for exhaust gases evolving in the vicinity of said burner head;
• a recuperative heat exchanger comprising an outer jacket and an inner jacket coaxial with each other and spaced from said burner assembly, said inner jacket forming part of said fuel-gas conduit, said outer jacket defining with said inner jacket an extension of said discharge duct open toward the atmosphere;
• and
• an inlet for atmospheric combustion air communicating with said intermediate tube at an extremity thereof remote from said burner head whereby said combustion air is preheated through said intermediate tube by high-temperature exhaust gases leaving the vicinity of said burner head, said exhaust gases thereupon entering said extension to preheat incoming fuel gas in said conduit through said inner jacket before escaping into the atmosphere.