Clamshell retainer used in hollow fiber membrane devices

Claim 1

A process for separating a feed gas mixture using a membrane separation device containing a plurality of hollow fiber semi-permeable gas separation membranes, comprising: (1) contacting one side of said membranes with a feed gas mixture under pressure; (2) maintaining a pressure differential across the membranes under conditions such that at least one gaseous component in the feed gas mixture selectively permeates through the membranes from the higher pressure side to the lower pressure side of said membranes; (3) removing from the lower pressure side of said membranes permeated gas which is enriched in at least one selectively permeating gaseous component; and (4) removing from the higher pressure side of said membranes non-permeated gas which is depleted in at least one selectively permeating gaseous component, wherein said device comprises: A. a hollow fiber membrane bundle containing said plurality of hollow fiber semi-permeable gas separation membranes; B. a tubesheet on each end of said bundle, each tubesheet having a radially outward surface with a circumferential groove therein, an inner face intersected by said hollow fiber membranes, said hollow fiber membranes being sealingly secured at each end in the respective tubesheet and communicating therethrough, and an outer face with a peripheral surface; C. first and second end caps, each having a radially outward surface and an inner face with a peripheral flange, said flange being positioned and adapted to sealingly mate against the mating peripheral surface on the outer face of an adjacent respective tubesheet, each flange having sufficient width in the axial direction to provide an enclosed space between the inner face of said end cap and the outer face of the adjacent tubesheet, the space serving as a fluid inlet or outlet region, and each end cap having a circumferential groove in the radially outward surface thereof; D. a clamshell retainer means for each adjacent end cap and associated tubesheet, said clamshell retainer means having the configuration of a segmented collar with a plurality of segments, the segments together forming the collar with flange portions on each segment extending radially inwardly, the flange portions of each segment being adapted to fit matingly, respectively, and coordinately into the peripheral groove pair of each respective end cap and associated tubesheet, the spacing between the flanges being such as to urge each end cap and associated tubesheet snugly together in a sealing relationship; E. a circumferential keeper means closely surrounding each clamshell retainer means to hold the flanges of the clamshell retainer means in the respective grooves in each end cap and associated tubesheet; F. a hollow envelope enclosing said hollow fiber membrane bundle, said envelope having ends which are fitted sealingly against each respective tubesheet to provide an enclosed space around the hollow fiber membrane bundle; and G. respective ports extending through each end cap and through said keeper means and said hollow envelope to provide fluid communication into and out of said device.