Clamshell retainer used in hollow fiber membrane devices

• US 5,211,728 A
• Filed: 06/04/1992
• Issued: 05/18/1993
• Est. Priority Date: 09/30/1991
• Status: Expired due to Term

• Current Assignee: MG Generon, Inc.
• Original Assignee: The Dow Chemical Company (Dow, Inc.)
• Inventors: Trimmer, Johnny L.
• Primary Examiner(s): SPITZER, ROBERT H
• Application Number:
  US07/893,306
• Time in Patent Office: 348 Days
• Field of Search: 55/16, 55/68, 55/158, 210/610, 210/321.78, 210/321.79, 210/321.8, 210/321.87, 210/321.88, 210/321.89, 210/500.23
• US Class Current: 95/47
• CPC Class Codes: B01D 2313/42 Catalysts within the flow path
• CPC Class Codes: B01D 2317/02 Elements in series
• CPC Class Codes: B01D 2317/04 Elements in parallel
• CPC Class Codes: B01D 2319/04 Elements in parallel
• CPC Class Codes: B01D 53/22 by diffusion manufacturing semi-permeable membranes B01D67/00; form, structure or properties of semi-permeable membranes B01D69/00; material for semi-permeable membranes B01D71/00
• CPC Class Codes: B01D 63/02 Hollow fibre modules
• CPC Class Codes: B01D 63/031 Two or more types of hollow fibres within one bundle or within one potting or tube-sheet
• CPC Class Codes: B01D 63/04 comprising multiple hollow fibre assemblies
• CPC Class Codes: B01D 65/00 Accessories or auxiliary operations, in general, for separation processes or apparatus using semi-permeable membranes
• CPC Class Codes: F16L 55/115 Caps F16L55/1286 takes precedence

Abstract

The invention relates to a hollow fiber membrane device having a hollow fiber membrane bundle with tubesheets, separable end caps, clamshell-shaped retainers for joining the end caps to the tubesheets, associated circumferential keepers which positionally constrain the clamshell-shaped retainers, and an optional envelope which encloses the membrane bundle.

Claims

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.

2. The process of claim 1 wherein said feed gas mixture comprises at least one of the gases selected from the group consisting of hydrogen, helium, oxygen, nitrogen, carbon monoxide, carbon dioxide, water vapor, hydrogen sulfide, ammonia, and light hydrocarbons.

3. The process of claim 2 wherein the pressure of the feed gas mixture is between about 10 psig and about 2000 psig.

4. The process of claim 3 wherein the temperature of the feed gas mixture is between about 0°

C. and about 150°

C.

5. The process of claim 3 wherein the temperature of said membrane is between about 0°

C. and about 150°

C.

6. A means for attaching an end cap to a tubesheet of a hollow fiber membrane separation module, the tubesheet having an inner face intersected by a plurality of hollow fiber membranes and an outer face, the end cap and the tubesheet having mating peripheral surfaces and the end cap and tubesheet each having an outer peripheral surface, comprising:

A. a peripheral circumferential groove in the outer surface of each of the end cap and tubesheet, the groove in the outer surface of the tubesheet being adjacent to the inner face thereof;

B. clamshell retainer means for each adjacent end cap and associated tubesheet in the form of a segmented collar with a plurality of curved segments, the segments together forming a substantially complete cylindrical collar with flange portions adjacent to both edges thereof, the 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 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; and

C. 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.

7. A means for attaching a tubesheet of a second hollow fiber membrane separation module to a tubesheet of a first hollow fiber membrane separation module, the tubesheets each having an inner face intersected by a plurality of hollow fiber membranes and an outer face, the tubesheet of the second module and the tubesheet of the first module having mating peripheral surfaces and the tubesheet of the second module and the tubesheet of the first module each having an outer peripheral surface, comprising:

A. a peripheral circumferential groove in the outer surface of each of the tubesheets, the groove in the outer surface of the tubesheets being adjacent to the inner face thereof;

B. clamshell retainer means for the tubesheets in the form of a segmented collar with a plurality of curved segments, the segments together forming a substantially complete cylindrical collar with flange portions adjacent to both edges thereof, the 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 grooves of the tubesheets, the spacing between the flanges being such as to urge the tubesheets together in a sealing relationship; and

C. a circumferential keeper means closely surrounding each clamshell retainer means to hold the flanges of the clamshell retainer means in the grooves in each tubesheet.

8. A housing device for a hollow fiber membrane separation module having a hollow fiber membrane bundle with a tubesheet on each end of the bundle, each tubesheet having a circumferential groove in the radially outward surface, an inner face intersected by a plurality of hollow fiber membranes and an outer face, the hollow fiber membranes being sealingly secured at each end in the respective tubesheet and communicating therethrough, comprising:

A. 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 of each end cap;

B. 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; and

C. 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.

9. The device of claim 8 additionally comprising:

D. 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

E. 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.

10. The device of claim 9 wherein said clamshell retainer is comprised of non-contiguous segments.

11. The device of claim 9 wherein said clamshell retainer means is comprised of no more than two segments.

12. The device of claim 9 wherein said circumferential keeper means is comprised of a clamp of adjustable sizing.

13. The device of claim 9 wherein said circumferential keeper means is comprised of a two-part cylindria keeper, joined along one axial edge by means of a hinge and joined along the other edge by a clamping means.

14. The device of claim 9 wherein said circumferential keeper means is comprised of two cylindrical sections, joined along both axial edges by a clamping means.

15. The device of claim 9 wherein said hollow envelope serves as the circumferential keeper means.

16. The device of claim 9 wherein said circumferential grooves, said flanges extending radially inwardly from said clamshell retainer means, and peripheral interior edges of the ends of said hollow envelope are chamfered such that said clamshell retainer means and said hollow envelope are more easily assembled.

17. The device of claim 9 wherein said end cap possesses a means for indexing and aligning said circumferential keeper means.

18. The device of claim 17 wherein said indexing and aligning means is a cap screw, set screw, or pin.

19. A hollow fiber membrane separation device comprising:

A. a hollow fiber membrane bundle containing a plurality of hollow fiber semi-permeable 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 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; and

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.

20. The device of claim 19 additionally comprising:

F. a hollow envelope enclosing said hollow fiber membrane bundle, said envelope having ends 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.

21. The device of claim 20 wherein said clamshell retainer is comprised of non-contiguous segments.

22. The device of claim 20 wherein said clamshell retainer means is comprised of no more than two segments.

23. The device of claim 20 wherein said circumferential keeper means is comprised of a clamp of adjustable sizing.

24. The device of claim 20 wherein said circumferential keeper means is comprised of a two-part cylindrical keeper, joined along one axial edge by means of a hinge and joined along the other edge by a clamping means.

25. The device of claim 20 wherein said circumferential keeper means is comprised of two cylindrical sections, joined along both axial edges by a clamping means.

26. The device of claim 20 wherein said hollow envelope serves as the circumferential keeper means.

27. The device of claim 20 wherein said circumferential grooves, said flanges extending radially inwardly from said clamshell retainer means, and peripheral interior edges of the ends of said hollow envelope are chamfered such that said clamshell retainer means and said hollow envelope are more easily assembled.

28. The device of claim 20 wherein said end cap possesses a means for indexing and aligning said circumferential means.

29. The device of claim 28 wherein said indexing and aligning means is a set screw, cap screw, or pin.

30. The device of claim 20 wherein said hollow fiber membranes comprise at least one polymer selected from the group consisting of olefinic polymers;

polytetrafluoroethylene;

cellulosic esters;

cellulose ethers;

regenerated cellulose;

polyamides;

polyetherketones;

polyestercarbonates;

polycarbonates;

polyesters;

polyarylates;

polyethers;

polybenzoxazoles;

polyoxadiazoles;

polytriazoles;

polycyanoarylethers;

polyamideimides;

polythioethers;

polystyrenes;

polysulfones;

polyimides;

polyetherimides;

polyethersulfones; and

copolymers and physical blends thereof.

31. The device of claim 30 wherein said hollow fiber membranes have an outside diameter in the range of about 50 microns to about 400 microns.

32. The device of claim 31 wherein said hollow fiber membranes have an outside to inside diameter ratio of between about 1.5 and about 1.15.

33. The device of claim 32 wherein the hollow fiber membranes are asymmetric.

34. The device of claim 32 wherein the hollow fiber membranes are composite.

35. The device of claim 32 wherein the hollow fiber membrane bundle is parallel-wrapped.

36. The device of claim 32 wherein the hollow fiber membrane bundle is bias-wrapped.