Recuperator for a radiating tube burner

A heat recuperator for a radiant tube burner having a burner pipe and an exhaust pipe, the burner being positioned at the inlet of the burner pipe, the recuperator being positioned at the outlet of the exhaust pipe, and comprising a heat exchanger positioned inside a connecting pipe designed to be connected to the exhaust pipe so as to perform counter-current preheating of the combustion air by part of the flue gases, the exchanger comprising:

• an outbound section for directing the air that is to be preheated toward a ferrule positioned at the end of the recuperator at the flue gas inlet end,
• and a return section opening toward a line supplying the burner with air, the ferrule defining a path for reversing the direction of flow of the combustion air and directing it toward the return section,
• the assembly being designed so that part of the flue gases is entrained by and mixed with the combustion air,
• the heat exchanger occupying just part of the cross section of the connecting pipe, the other part remaining free for the passage of the flue gases toward a discharge,
• wherein:
• the outbound section of the exchanger comprises a plurality of exchanger tubes which are parallel to the axis of the connecting pipe, for the passage of the combustion air, the flue gases exchanging heat with the air across the exchanger tubes, the two fluids having parallel flows in opposite directions,
• the exchanger tubes open to the inside of the ferrule,
• the air circuit is configured in a “hairpin” shape, the return section being radially offset in relation to the tubes of the outbound section and the cross sections of the exchanger tubes and of the return section being situated on the outside of one another.