Slit nozzle and method for manufacturing high-silicon steel strip

A slit nozzle having a double-tube structure, the slit nozzle comprising:

• an outer tube having a delivery port for a treatment gas in an axial direction and a closed end;
• an inner tube having a feeding port for the treatment gas on one end and an open end that is another end inside the closed end of the outer tube, the treatment gas configured to be fed through the feeding port and blown through the delivery port;
• and
• a flow-control plate disposed between the open end of the inner tube and an end of the delivery port, the flow-control plate closing a gap between the inner tube and the outer tube,
• wherein an opening is formed in a plane in which the flow-control plate is disposed only in a range of the flow-control plate of 27.5° or more and 332.5° or less in terms of a central angle with respect to a reference line passing through an axis of the outer tube and a central position in a width direction of the delivery port,
• wherein an area fraction, which is an area of the opening divided by an area of the range of the flow-control plate of 27.5° or more and 332.5° or less in terms of the central angle with respect to the reference line, is 55% or more and 75% or less, and
• wherein a width of the delivery port, in a direction perpendicular to the axis of the outer tube, is 5 mm or more and 20 mm or less and is 15% or less of an outer diameter of the outer tube.