Installations for the treatment, in gaseous medium, of a strip product

Claim 1

In an installation for the treatment, in a gaseous medium, of a band of product moving in a treatment zone situated between blower caissons supplied with treatment gas, the caissons having, on each side of the treatment zone, blower walls comprising groups of inlet and blower apertures for connection to a gas supply means and groups of outlet passages for exhausting gaseous medium from the treatment zone, these groups being arranged alternately with respect to the direction of movement of the band, the improvements comprising means in each group of apertures for forming a closed gaesous wall extending in a closed contour of rectangular configuration and surrounding the Inlet apertures to impose a degree of confinement on the gaseous medium inside the contour, said means including a plurality of closely spaced, relatively small blower apertures arranged along a contour or rectangular shape, of which the larger side is perpendicular to the direction of movement of the band and is at least equal to the width of this band, said inlet apertures being relatively large and arranged inside said contour, the section of each inlet aperture being at least twice as great as the section of each blower aperture, and additional blower apertures equally arranged and closely spaced along median lines regularly spaced and joining the two large sides of the said contour, the small side of each contour being greater than half the pitch along which the groups of inlet and blower apertures are distributed, and the sum of the sections of the outlet passages being greater than the sum of the sections of the inlet and blower apertures.