To provide a steel heating furnace for switching a fuel gas to the other without stopping the operation of the heating furnace or without a high facility cost even when the fuel gas is stopped in a regular service.
The steel heating furnace 11 has a tubular flame burner 12. The tubular flame burner 12 comprises a tubular combustion chamber 1 with one end opened, and a fuel blowing nozzle with a nozzle hole opened in an inner surface of the combustion chamber and an oxygen-containing gas blowing nozzle 2. The fuel blowing nozzle and the oxygen-containing gas blowing nozzle are disposed with the injection direction aligned with the substantially tangential direction of an inner circumferential surface of the combustion chamber, and a high calorie pipe 16 and a low calorie pipe 17 are passed through a fuel feed pipe 15 to feed the fuel to the fuel blowing nozzle 4 so as to feed at least two kinds of fuel of different heat generation in a switching manner.
FUJII YOSHIMOTO
TAKASHI KOICHI
KUSADA TAKAMITSU
