초록 ▼

The invention relates to a heat recuperator (R) for a radiating tube burner having a burner pipe and an exhaust pipe (1), the recuperator being placed at the outlet of the exhaust pipe (1) and including a heat exchanger (E) that comprises: an outgoing section (5) for directing the air to be preheate

The invention relates to a heat recuperator (R) for a radiating tube burner having a burner pipe and an exhaust pipe (1), the recuperator being placed at the outlet of the exhaust pipe (1) and including a heat exchanger (E) that comprises: an outgoing section (5) for directing the air to be preheated to a ferrule (6), placed on the end of the recuperator, from the fume intake side, and a return section (7) opening towards a pipe (8) for supplying air from the burner, the assembly being provided such that part of the fumes are led through, and mix with, the combustion air; the heat exchanger (E) occupies only part of the cross-section of the exhaust pipe (1), the other part (1a) of the cross-section remaining free for the fumes; the combustion air is heated by the fumes in the outgoing section (5) and in the return section (7), being radially shifted outside the outgoing section (5) and immersed in the fumes.

대표청구항 ▼

1. 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 heat recuperator comprising: a connecting pipe having a first end and a second end, the first end coupled to the outlet of the exhaust pipe such

1. 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 heat recuperator comprising: a connecting pipe having a first end and a second end, the first end coupled to the outlet of the exhaust pipe such that flue gases flow from the first end of the connecting pipe toward the second end;a heat exchanger positioned inside and occupying a first part of a cross section of the connecting pipe, a second part of the cross section remaining free for the passage of the flue gases toward a discharge of the connecting pipe, the heat exchanger comprising: an outbound section for directing air for combustion from an inlet at the second end of the connecting pipe toward the first end of the connecting pipe, the outbound section comprising a plurality of exchanger tubes arranged parallel to the axis of the connecting pipe for the passage of air for combustion, each exchanger tube including a tube wall, at least part of each tube wall forming a boundary between the air for combustion flowing toward the first end of the connecting pipe and at least part of the flue gases flowing toward the second end of the connecting pipe, such that the part of the flue gases provide counter-current preheating of the air for combustion across the tube walls;a ferrule positioned at the end of the heat exchanger nearest the first end of the connecting pipe and coupled to the plurality of exchanger tubes of the outbound section, the exchanger tubes opening to the inside of the ferrule; anda return section having an ejector end opening toward a line supplying the burner with air and an open end opposite the ejector end facing the ferrule, the return section being formed of a single tube which is radially offset in relation to the exchanger tubes of the outbound section, the cross sections of the plurality of exchanger tubes and of the single tube of the return section being situated on the outside of one another, and the cross section of the single tube of the return section being at least equal to the sum of the cross sections of the plurality of exchanger tubes, wherein: the ferrule is configured to reverse the direction of flow of the air for combustion from the plurality of exchanger tubes into the single tube of the return section,the air for combustion within the single tube of the return section flows from the ferrule toward the second end of the connecting pipe,the single tube of the return section includes an open end at the end of the heat exchanger nearest the first end of the connecting pipe, andthe open end of the single tube of the return section is spaced apart from the ferrule, such that the open end is fluidically coupled with the ferrule and with the flue gas inlet end of the exhaust pipe to entrain and mix part of the flue gases with the combustion air at the open end of and within the single tube of the return section. 2. The recuperator as claimed in claim 1, wherein the ferrule comprises an inlet curving toward an outlet, the inlet combining the flows from the plurality of exchanger tubes and the outlet opening into the open end of the return section. 3. The recuperator as claimed in claim 2, wherein the ejector end of the return section is curved near the first end of the connecting pipe. 4. The recuperator as claimed in claim 2, further comprising an air inlet line surrounded by a tubular jacket closed at its inner end and open at its other end into an air inlet chamber for the exchanger tubes, the tubular jacket being surrounded by flue gases so that the combustion air makes a first, preheating, outward and return trip before entering the exchanger tubes. 5. The recuperator as claimed in claim 1, wherein the ferrule comprises a cylindrical part extended upstream by a funnel which is connected to the return section, the funnel in its central part comprising a tubular extension that forms an injector for the combustion air, this extension being supported by radially directed cuffs placing an annular space into which the plurality of exchanger tubes open in communication with the inside of the tubular extension. 6. The recuperator as claimed in claim 1, wherein it is of all-welded construction with tubular elements and sheet metal components made of stainless steel. 7. The recuperator as claimed in claim 1, wherein a helicoid is positioned in at least one of the plurality of exchanger tubes. 8. The recuperator as claimed in claim 1, wherein each of the plurality of exchanger tubes is surrounded by a jacket tube to form an annular passage therebetween, the combustion air flowing through the plurality of exchanger tubes while the flue gases flow through the annular passages. 9. The recuperator as claimed in claim 8, wherein each jacket tube passes in a fluidtight manner through a partition which delimits, at the end of the connecting pipe, a chamber connected to the flue gas discharge, each jacket tube opening into this chamber. 10. The recuperator as claimed in claim 1, wherein the plurality of exchanger tubes is surrounded by a jacket wall and the flue gases flow between the exterior surface of the plurality of exchanger tubes and the jacket wall. 11. The recuperator as claimed in claim 1, further comprising a bypass pipe for short-circuiting part of the cold air directly to the burner without passing via the recuperator as long as the radiant tube has not reached the self-ignition temperature of the fuel, with a shut-off member provided on the air intended for igniting the burner. 12. The recuperator as claimed in claim 1, wherein the plurality of exchanger tubes have different diameters, the diameter being greater in the upper part and smaller in the lower part. 13. The recuperator as claimed in claim 1, wherein each of the plurality of exchanger tubes is welded at just one end, the hot end connected to the ferrule, while at the other end they each of the plurality of exchanger tubes is engaged with a fluidtight sliding fit in an end wall of the exhaust pipe.