Apparatus and method for producing a laminar flow of constant velocity

Abstract

The present invention relates to an apparatus and method for directing a constant velocity laminar flow of a fluid along a surface of a planar substrate. The apparatus comprises a plurality of serially arranged, individual passageways interconnecting an inlet and an outlet. The inlet is adapted to be connected to a supply of fluid, while the outlet is positioned adjacent the surface of the substrate for directing the uniform laminar flow of fluid onto the substrate surface. The individual passageways are adapted to vary the velocity of the fluid as it passes through the passageways to ensure that a laminar flow of constant velocity is produced along the surface of the substrate. In the preferred embodiment of the invention, the apparatus is utilized to apply a metal oxide coating to a sheet of moving glass. In these instances, the outlet is an elongate nozzle extending transversely relative to the path of the moving glass to enable a gaseous reactant utilized to form the metal oxide coating to be applied across the entire width of the glass sheet. In one embodiment of the invention, the individual passageways are alternating converging and diverging passageways which function to evenly distribute the fluid within the passageways such that the fluid exits the elongate outlet at a relatively constant velocity to produce a uniform laminar flow of the gaseous reactant across the glass sheet.