NOVELTY - The device comprises a number of sets of hollow fiber membranes to enable contacting patterns for three internal flow streams. The multiple streams permit maximum contact with the hollow fiber membranes, resulting in improved yields.    USE - For separating gases from gas mixture.    ADVANTAGE - Yields high purity non-permeate product stream to internally arranged gas separation membranes with multiple streams and high pressure retentate outlet. Easy to manufacture and adapts to wide ranging requirements due to provision of multiple hollow fiber membrane bundles.    DETAILED DESCRIPTION - A hollow fiber membrane fluid separation device has a tubular shell (2) circumscribing tubular sheets (5, 6) at both ends respectively. The outer hollow fiber membrane bundle (3) inside the shell is installed between sheets. Sealing caps (9,12) seal the ends of the shell. An internal hollow fiber bundle (4) permeates inside the outer fiber membrane bundle, extends on either sides of the sealing caps and is installed with tubular sheets (7,8) at either ends. Two or more sealing caps (15,18) seal ends of the inner fiber bundle. A feed inlet region (10) is formed between the sealing cap and the tubular sheet (5). A feed inlet tube (11) is connected to the feed inlet region for feeding a gas mixture to be separated. A non-permeable outlet region (13) is formed between the tubular sheet (6) and the sealing cap (12) which accumulates a gas from the gas mixture which could not penetrate the outer fiber bundle. A retentate outlet (14) is connected to the non-permeable outlet region for removing the accumulated gas. An internal feed inlet (22) formed between the two membrane bundle permits entry of gas mixture from shell side to the internal fiber bundle. A permeate outlet (23) installed in the periphery of the shell ejects out gas permeate through the outer fiber membrane. Permeate outlets (17,18), connected to permeate region of the internal fiber membrane on either side of the shell, eject out permeated gas from the internal fiber membrane. The fluid mixture consists of hydrogen, oxygen, helium, nitrogen, methane, carbon monoxide and carbon dioxide.    DESCRIPTION OF DRAWING(S) - The figure shows the perspective cross sectional view of the hollow fiber membrane fluid separation device.    Tubular shell (2)    Outer hollow fiber membrane bundle (3)    Internal hollow fiber bundle (4)    Tubular sheets (5-8)    Sealing caps (9,12,15,18)    Feed inlet region (10)    Feed inlet tube (11)    Non-permeable outlet region (13)    Retentate outlet (14)    Permeate outlets (17,23)    Internal feed inlet (22)