Abstract: The present invention provides a scroll pump device comprising external and internal scroll members, and wherein the scroll pump device is separated into inner and outer zones. The flow streams in the two zones are kept separate, and each stream may have different chemical compositions and flow rates. The scroll pump system can provide both vacuum and pressure flow streams in a compact lightweight package, and may be used for the separation and concentration of oxygen from atmospheric air, for use, inter alia, in portable medical systems.

Abstract: Gas compression system comprising a compression cylinder having a gas inlet, a compressed gas outlet, and one or more liquid transfer ports; a pump having a suction and a discharge; and a compressor liquid. The system also includes any of the following: a pressure intensifier having an inlet in flow communication with the pump and an outlet in flow communication with the compression cylinder; a feed eductor in flow communication with the discharge of the pump, with a reservoir containing a portion of the compressor liquid, and with the compression cylinder; a drain eductor in flow communication with the discharge of the pump, with the compression cylinder, and with a reservoir containing a portion of the compressor liquid; and a variable-volume compressor liquid accumulator in flow communication with the discharge of the pump.