| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for preventing the unstability of the passing-through property of a steel sheet and the degradation of the shape of the steel sheet caused by the channeling of a gas jet seal between plural zones in a continuous annealing furnace, and a nozzle therefor. SOLUTION: The gas is supplied from at least two positions of a slit nozzle, in the width direction of a gas chamber 3 and the distribution of the gas supplying quantity to each position is varied to control the channeling. The distribution of the gas supplying quantity can periodically be varied. One or more among temp. difference in width direction of the furnace, temp. difference of the steel sheet, component difference of atmosphere in the furnace and extending quantity at one side of the steel sheet in the width direction of the furnace, are measured, and based on the result, the distribution of the gas supplying quantity can be controlled. The distribution of the gas supplying quantity can be controlled so that the directions of the channeling at the inlet side and the outlet side of the furnace zone become reverse. In the nozzle structure, gas supplying holes in the width direction of the gas chamber in the nozzle are arranged at two positions and when denoting C as the cross sectional area of the gas chamber and S as the area of the opening part of the nozzle, the value of C/S is preferably adjusted to 0.03-10.0.
|
