Vacuum Ejector With Tripped Diverging Exit Flow

Abstract

So as to offer greater design freedom for the upstream nozzles since the resistance upon exit of the jet flow into ambient pressure is encountered less abruptly, the invention provides al. multi-stage ejector for generating a vacuum from a source of compressed air by passing said compressed air through a series of nozzles, accelerating said compressed air, and entraining air so as to form a jet flow in two or more stages including at least a drive stage and a second stage and generating a vacuum across each stage before ejecting said jet flow through an outlet of the ejector, wherein said ejector outlet is formed as a nozzle extending to the outlet end of the ejector and arranged to receive the jet flow from the final stage of the ejector, and wherein said ejector outlet nozzle includes a diverging section extending at an angle of divergence to the direction of airflow, said diverging section terminating in a stepwise expansion in the cross-sectional flow area, as viewed in a direction perpendicular to the direction of airflow through the ejector outlet nozzle.

Dependencies are inferred from the claim text.