Oxygen partial pressure controller for a pressure swing adsorption system

Claim 1

An oxygen partial pressure controller for regulating the oxygen partial pressure (PPO 2 ) of the product gas of a pressure swing adsorption oxygen enriching system which is operating at a system pressure applied to the inlet of the controller, in which the PPO 2 of the product gas is inversely proportional to the flow of product gas through the system, said controller utilizing a conventional PPO 2 monitor and signal conditioning elements, said controller comprising: a bleed valve for increasing product gas flow through the controller by increasing the bleed flow of product gas, a diaphragm enclosing a chamber and responsive to chamber pressure, a line coupling said chamber to said product gas at system pressure, and an outlet venting said chamber to atmospheric pressure, linkage means coupled to said diaphragm for controlling the operation of said bleed valve, and a solenoid valve responsive to said PPO 2 monitor and said signal conditioning means for controlling chamber pressure, wherein said solenoid valve is operable to block said outlet thereby increasing the chamber pressure to equal system pressure, and wherein said solenoid valve is operable to open said outlet thereby decreasing the chamber pressure to equal atmospheric pressure, wherein high chamber pressure causes said bleed valve to open increasing gas flow and lowering PPO 2 , and low chamber pressure causes said bleed valve to close decreasing gas flow and increasing PPO 2 .