DEVICE FOR GENERATING A GAS JET IN PROCESSES FOR COATING METAL STRIPS

摘要

The device has a gas flow levelling pipe (3), which defines a continuous curved development surface (Z), at comprising a collector (4) to which a nozzle (10) is fixed, a delivery manifold (1), in order to introduce pressurized gas into the pre-chamber (2) through the holes (12), a first holed partition (5) and a second holed partition (6) within the levelling pipe (3), arranged perpendicular to the curved development surface (Z) of the pipe (3).

主权项

1. A device for generating a flag laminar gas jet, in particular suitable for hot coating processes for metal strips, comprising
a longitudinal delivery manifold for having a peripheral wall, the peripheral wall being provided with first holes, a levelling pre-chamber communicating with said longitudinal delivery manifold through said first holes, a levelling pipe communicating at a first end thereof with said levelling pre-chamber, a nozzle adapted to generate the flat laminar gas jet, said levelling pipe communicating at a second end thereof with said nozzle, said second end being opposite to and having a smaller section than the first end, so as to be tapered and to create a gas flow path from said levelling pre-chamber to the nozzle, said gas flow path defining a curved medial development surface, at least two holed partitions arranged in said levelling pipe and perpendicular to said curved medial development surface, thereby defining at least two successive, adjacent portions of the levelling pipe which are connected to each other,wherein the first holes are provided only in a first longitudinal sector of the peripheral wall of the longitudinal delivery manifold and said levelling pre-chamber extends externally at least about said first longitudinal sector,wherein a first portion of the levelling pipe extends externally about a second longitudinal sector of the peripheral wall of the longitudinal delivery manifold adjacent to the first longitudinal sector,and wherein a second portion of the levelling pipe is arranged in a substantially tangential direction with respect to the longitudinal delivery manifold downstream of said second longitudinal sector,whereby said curved medial development surface is represented by an ideal continuous curved surface without any angular points, so as to optimize the transformation of the gas flow from turbulent flow at the first end to laminar flow at the second end of the levelling pipe.