Desktop Gas Isotope Separation by Knudsen Pump

A gas separator which makes use of the molecular exchange flow of a Knudsen pump is fabricated. The Knudsen pump makes use of the thermal transpiration of rarefied gas in several sheets of porous membrane of 8 cm x 8 cm in size. The gas separator is desktop size, and it works near atmospheric pressure. The device continuously splits the feed gas flow into two flows of product gases at the total flow rate of 3 - 6 sccm. The difference of mole percentage between the product gases are around 1 % for neon isotope mixture and 50 % for helium-neon mixture. Present gas separator increases the mole fraction of trace gases in the feed mixture by about 4 5 times. The feasibility of the production of high purity gases by present method is also discussed.