Convective hood for heat treatment of a continuous strip

Abstract

A convective hood for transverse installation in a system for continuous heat treatment of moving strip material comprises blowing nozzles for blowing hot gas against the moving strip in an arrangement transverse to the direction of movement of the strip material; and a first transverse suction zone for the suction of hot gas. The first transverse suction zone comprises a first transverse section and a second transverse section. The first transverse section and the second transverse section are provided at the same side downstream or upstream of the movement of the strip material from the blowing nozzles when the convective hood is installed in a system for continuous heat treatment of moving strip material. The second transverse section is provided along the line for movement of the continuous strip material between the first transverse section and the blowing nozzles. The first transverse section comprises suction openings for suction of hot gas directly from outside the convective hood into the convective hood; the suction openings being in closed gas flow connection to a first manifold for recirculation of at least part of this hot gas to the blowing nozzles for blowing the hot gas onto the continuous strip material. The second transverse section comprises suction openings for suction of hot gas directly from outside the convective hood into the convective hood; the suction openings being in closed gas flow connection to a second manifold for exhausting 100% of this hot gas outside of the convective hood.