Descaling nozzle

摘要

A nozzle orifice of a nozzle ( 1 ) includes a tapered segment ( 16 ) extending from an elliptical discharge orifice ( 15 ) and having a taper angle theta of 30 to 80°, and a large-diameter segment ( 18 ) continuing with the tapered segment. The ratio of the inner diameter of large-diameter segment ( 18 ) relative to the minor diameter of the discharge orifice ( 15 ) is not less than 3 and less than 7. Also, the discharge how from the nozzle spreads in a single direction (width direction) within a plane perpendicular to the central axis of the nozzle and the erosion thickness angle is 1.5 to 3° in the direction (thickness direction), perpendicular to the width direction. Such a descaling nozzle enables that scale is removed efficiently at low pressure and/or low flow rate while restraining the cooling of a steel plate.