Patent ID: 7360551

Claim:
A fluid flow control system, comprising: a fluid inlet to receive a flow of process fluid; a first fluid outlet to provide a first portion of the flow of process fluid received at the fluid inlet; at least one second fluid outlet to provide a remaining portion of the flow of process fluid received at the fluid inlet; a pressure sensor, to measure a pressure of the process fluid in the fluid inlet and provide a pressure signal indicative of the pressure of the process fluid in the fluid inlet; a controller to receive the pressure signal, a pressure setpoint indicative of a desired pressure of the process fluid in the fluid inlet, and a ratio setpoint indicative of a ratio of the first portion of the flow of process fluid relative to the flow of process fluid received at the fluid inlet, to control amounts of the process fluid provided by the first fluid outlet and by the at least one second fluid outlet so that a ratio of the first portion of the flow of process fluid relative to the flow of process fluid received at the fluid inlet is maintained at the ratio setpoint independent of changes in the pressure of the process fluid in the fluid inlet.