VARIABLEEAREA FLOW EJECTOR

摘要

A variable flow ejector for use in controlling the amount of bypass flow in a fluid delivery system which includes a pump, a metering orifice and a bypass line for circulating a variable amount of flow from the pump outlet to the pump inlet to control the pressure drop across the orifice. The bypass flow enters the ejector through a variable area nozzle coaxially disposed with respect to a stream from a source of fluid whereby the velocity head of the bypass flow is recovered as pressure head at the pump inlet for increased efficiency. The bypass flow is controlled by varying the area of the ejector nozzle as a combined function proportional to the pressure drop across the orifice plus the time integral of the error in the pressure drop across the orifice.