Abstract: A method and apparatus are provided for controlling the amount of purging that occurs within a membrane separation device. The membrane separation device includes a membrane separation component and sweep controlling component. Within the membrane separation component, a major portion of the non-permeate gas is sent out of the membrane separation device to work, while a minor portion is diverted for use as a sweep gas. The sweep gas is controlled by a valve that cycles with a device, such as a compressor. Thus, the membrane separation device is on when the compressor is on and is off when the compressor is off. As such, the membrane separation device is not required to sweep at all times.

Abstract: A method and apparatus are provided for controlling the amount of purging that occurs within a membrane separation device. The membrane separation device includes a membrane separation component and sweep controlling component. Within the membrane separation component, a major portion of the non-permeate gas is sent out of the membrane separation device to work, while a minor portion is diverted for use as a sweep gas. The sweep gas is controlled by a valve that cycles with a device, such as a compressor. Thus, the membrane separation device is on when the compressor is on and is off when the compressor is off. As such, the membrane separation device is not required to sweep at all times.

Abstract: An apparatus and method for separating breathable oxygen gas from a source of gas and then humidifying the oxygen gas while preventing over humidification of the oxygen gas, the apparatus comprising a gas pathway located on a first side of a water transfer member, an oxygen gas pathway located on a second side of the water transfer member and a separator for separating the breathable oxygen gas from a gas located on the first side of the water transfer member and directing the breathable oxygen gas past the second side of the water transfer member while maintaining the pressure of the gas substantially equal to the pressure of the breathable oxygen gas to thereby humidify the breathable oxygen gas while preventing a moisture condensation in the breathable oxygen gas.