Gas permeation apparatus having permeate rate controlled valving

A permeator system for separating one gas from a mixture of said one gas and at least one other gas, comprising:

• a. at least two permeators connected in parallel, said permeators each having a membrane more permeable to said one gas than said other gas such that said one gas is separated from the mixture in said at least two permeators;
• b. an inlet line for feeding the mixture of gases to the permeator system;
• c. an outlet line for withdrawal of permeated one gas;
• d. each of said permeators having a first connecting line for feeding the gas mixture from the inlet line into each permeator to contact each membrane and a second connecting line for feeding said permeated one gas from each permeator to said outlet line;
• e. at least one of said connecting lines of one permeator having a valve means therein for stopping the flow of permeated gas from said one permeator to said outlet line;
• and
• f. a flow detector means connected in said outlet line, said flow detector means being connected to said valve means for actuating said valve means to lower the amount of effective membrane surface area in use when permeate flow rate in said outlet line falls below a predetermined rate and to increase the amount of effective membrane surface area in use when permeate flow rate rises above said predetermined rate, said surface area increases and decreases being effected by changing the number of permeators in use.