Method and radiant-heating device for heating an industrial furnace

A radiant-heating device for heating an industrial furnace comprising:

• a) a first burner unit (1) including:
• a1) a first burner (2) that generates a hot exhaust gas by burning a fuel with combustion air,
• a2) a first air supplier (60), via which the first burner (2) is supplied with fresh air, and
• a3) a first elongated radiant-heating pipe (20), which includes a rearward end (20a) connected with the first burner (2) and a forward end (20b) spaced from the rearward end (20a) and in which the hot exhaust gas generated by the first burner (2) flows from the rearward end (20a) to the forward end (20b) of the first radiant-heating pipe (20) and supplies heat energy along this path via the pipe wall of the first radiant-heating pipe (20),
• b) a second burner unit (1′) including:
• b1) a second burner (2′) that generates a hot exhaust gas by burning a fuel with combustion air,
• b2) a second air supplier (60′), via which the second burner (2′) is supplied with fresh air, and
• b3) a second elongated radiant-heating pipe (20′), which includes a rearward end (20a′) connected with the second burner (2′) and a forward end (20b′) spaced from the rearward end (20a′) and in which the hot exhaust gas generated by the second burner (2′) flows from the rearward end (20a′) to the forward end (20b′) of the second radiant-heating pipe (20′) and supplies heat energy along this path via the pipe wall of the second radiant-heating pipe (20′),
• c) at least one further burner unit (1″) including:
• c1) a further burner (2″) that generates a hot exhaust gas by burning a fuel with combustion air,
• c2) a further air supplier, via which the second burner (2″) is supplied with fresh air, and
• c3) a further elongated radiant-heating pipe (20″), which includes a rearward end connected with the further burner (2″) and a forward end spaced from the rearward end and in which the hot exhaust gas generated by the further burner (2″) flows from the rearward end to the forward end of the further radiant-heating pipe (20″) and supplies heat energy along this path via the pipe wall of the further radiant-heating pipe (20″),
• d) a first connection element (50) that connects the forward end of the first radiant-heating pipe (20) with the rearward end of the second radiant-heating pipe (20′), so that at least a portion of the exhaust gas within the first radiant-heating pipe (20′) is conducted to the second burner (2′) and is burned again using the second burner (2′),
• e) a second connection element (50′) that connects the forward end of the second radiant-heating pipe (20′) with the rearward end of the further radiant-heating pipe (20″), so that at least a portion of the exhaust gas within the second radiant-heating pipe (20′) is conducted to the further burner (2″) and is burned again using the further burner (2″), and
• f) a further connection element (50″) that connects the forward end of the further radiant-heating pipe (20″) with the rearward end of another further radiant-heating pipe or of the first radiant-heating pipe (20), so that at least a portion of the exhaust gas within the further radiant-heating pipe (20″) is conducted to the another further burner and is burned again using the another further burner or the portion of the exhaust gas within the further radiant-heating pipe (20″) is conducted to the first burner (2) and is burned again using the first burner (2).

A heating system for an industrial furnace comprising a plurality of radiant-heating devices wherein at least one of said plurality of radiant-heating systems includes:

• a) a first burner unit (1) including:
• a1) a first burner (2) that generates a hot exhaust gas by burning a fuel with combustion air,
• a2) a first air supplier (60), via which the first burner (2) is supplied with fresh air, and
• a3) a first elongated radiant-heating pipe (20), which includes a rearward end (20a) connected with the first burner (2) and a forward end (20b) spaced from the rearward end (20a) and in which the hot exhaust gas generated by the first burner (2) flows from the rearward end (20a) to the forward end (20b) of the first radiant-heating pipe (20) and supplies heat energy along this path to the pipe wall of the first radiant-heating pipe (20),
• b) a second burner unit (1′) including:
• b1) a second burner (2′) that generates a hot exhaust gas by burning a fuel with combustion air,
• b2) a second air supplier (60′), via which the second burner (2′) is supplied with fresh air, and
• b3) a second elongated radiant-heating pipe (20′), which includes a rearward end (20a′) connected with the second burner (2′) and a forward end (20b′) spaced from the rearward end (20a′) and in which the hot exhaust gas generated by the second burner (2′) flows from the rearward end (20a′) to the forward end (20b′) of the second radiant-heating pipe (20′) and supplies heat energy along this path to the pipe wall of the second radiant-heating pipe (20′),
• c) a first connection element (50) that connects the rearward end (20a) of the first radiant-heating pipe (20) with the forward end (20b′) of the second radiant-heating pipe (20′), so that at least a portion of the exhaust gas generated in the second radiant-heating pipe (20′) is conducted to the first burner (2) and is burned again using the first burner (2),
• d) a second connection element (50′) that connects the rearward end (20a′) of the second radiant-heating pipe (20′) with the forward end (20b) of the first radiant-heating pipe (20), so that at least a portion of the exhaust gas generated in the first radiant-heating pipe (20) is conducted to the second burner (2′) and is burned again using the second burner (2′).

A method for indirectly heating an industrial furnace comprising the method steps:

• a) generating a hot exhaust gas using a first burner (1) that is attached to a first radiant-heating pipe (20),
• b) streaming the exhaust gas in and along the first radiant-heating pipe (20) from the rearward end (20a) to the forward end (20b) of the first radiant-heating pipe (20), wherein radiant heat is supplied along the way to a furnace chamber (200),
• c) diverting at least a portion of the exhaust gas, which still has residual heat energy, at the forward end (20b) of the first radiant-heating pipe (20) to the rearward end (20a′) of a second radiant-heating pipe (20′),
• d) generating a hot exhaust gas using a second burner (1′) that is attached to the second radiant-heating pipe (20′),
• e) streaming the exhaust gas, together with the diverted portion of the exhaust gas still having residual heat energy from the first radiant-heating pipe (20), in and along the second radiant-heating pipe (20′) from the rearward end (20a′) to the forward end (20b′) of the second radiant-heating pipe (20′), wherein radiant heat is supplied along the way to the furnace chamber (200), and
• f) diverting at least a portion of the exhaust gas, which still has residual heat energy, at the forward end (20b′) of the second radiant-heating pipe (20′) to the rearward end (20a) of the first radiant-heating pipe (20).

A method for indirectly heating an industrial furnace comprising the steps:

• a) generating a hot exhaust gas using a first burner (1) that is attached to a first radiant-heating pipe (20),
• b) streaming the exhaust gas in and along the first radiant-heating pipe (20) from the rearward end (20a) to the forward end (20b) of the first radiant-heating pipe (20), wherein radiant heat is supplied along the way to a furnace chamber (200),
• c) diverting at least a portion of the exhaust gas, which still has residual heat energy, at the forward end (20b) of the first radiant-heating pipe (20) to the rearward end (20a′) of a second radiant-heating pipe (20′),
• d) generating a hot exhaust gas using a second burner (1′) that is attached to the second radiant-heating pipe (20′),
• e) streaming the exhaust gas, together with the diverted portion of the exhaust gas still having residual heat energy from the first radiant-heating pipe (20), in and along the second radiant-heating pipe (20′) from the rearward end (20a′) to the forward end (20b′) of the second radiant-heating pipe (20′), wherein radiant heat is supplied along the way to the furnace chamber (200),
• f) diverting at least a portion of the exhaust gas, which still has residual heat energy, at the forward end (20b′) of the second radiant-heating pipe (20′) to the rearward end (20a″) of a further radiant-heating pipe (20″).