PURPOSE: To provide the burner structure of a direct-fired heater arranged above a continuous hot-dip metal coating device and capable of preventing the uneven burning in heat treatment.
CONSTITUTION: A gas nozzle 3 pierced with blowoff ports flatly or at regular intervals is provided in the heater, and the similar air nozzles 4 are furnished on the upper and lower surfaces of the nozzle 3. A couple of upper and lower burner tiles 5a and 5b having an L-shaped cross section and with the inner surface smoothly curved are mounted to cover the nozzles 3 and 4 so that a slit 6 formed at the joint is aligned with the blowoff ports 3a and 4a. The flame is flatly and uniformly injected in the cross direction and collided with a steel sheet, hence the steel sheet 1 is uniformly heated and evenly burned in the cross direction, the sheet is rapidly heated, the alloying performance is improved, and the steel sheet 1 having a beautiful surface is obtained.
FUKUSATO TOSHIRO
SHIMAO TERUO
