Membrane separation device

• US 4,902,416 A
• Filed: 01/26/1989
• Issued: 02/20/1990
• Est. Priority Date: 11/20/1987
• Status: Expired due to Fees

• Current Assignee: The Dow Chemical Company (Dow, Inc.)
• Original Assignee: The Dow Chemical Company (Dow, Inc.)
• Inventors: Schroeder, Lawrence R., Caskey, Terrence L.
• Primary Examiner(s): SPEAR JR, FRANK
• Application Number:
  US07/303,505
• Time in Patent Office: 390 Days
• Field of Search: 210/356, 210/321.67, 210/321.74, 210/321.83, 210/929
• US Class Current: 210/321.67
• CPC Class Codes: B01D 63/02 Hollow fibre modules
• CPC Class Codes: B01D 63/024 with a single potted end
• CPC Class Codes: B01D 63/0241 being U-shaped
• CPC Class Codes: B01D 63/025 Bobbin units
• 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 63/043 with separate tube sheets
• CPC Class Codes: B01D 63/046 in separate housings

Abstract

This invention relates to a hollow fiber membrane device which can accommodate large changes in fiber dimension due to fiber swelling or contraction during operation.

Claims

1. A hollow fiber membrane device comprised of:

(1) a plurality of non-woven hollow fiber membranes formed into at least one non-random bundle wherein the membranes are capable of separating at least one of the components from a liquid feed mixture;

(2) at least one tubesheet comprised of a thermoplastic or thermoset material wherein the end(s) of the hollow fiber bundle(s) are embedded in the tubesheet(s);

(3) at least one core wherein at least one non-woven hollow fiber bundle is wrapped in a spiral fashion about at least one core in such a manner that the non-woven hollow fiber bundle(s) is first formed and then wrapped spirally about the core(s) as a completed bundle(s) such that the fibers comprising the bundle(s) may expand and contract without substantial damage to the fibers;

(4) a means for introducing the feed into the membrane device;

(5) a means for removing the non-permeate from the membrane device;

(6) a means for removing the permeate from the membrane device; and

(7) a case which contains the hollow fiber bundle(s), core(s) and tubesheet(s) wherein the case allows the hollow fibers to expand and contract without substantial damage to the fibers, wherein there is substantial void volume within the case external to the hollow fiber bundle(s) which is nonuniformly distributed.

2. The membrane device of claim 1 wherein the device is capable of accommodating longitudinal expansion of the hollow fiber bundle(s) of up to about 100 percent.

3. The membrane device of claim 2 wherein the minimum inner diameter of the case, ID_min is defined by the equation:

##EQU4## wherein D is the core diameter,

s is the maximum longitudinal swelling expressed as a fraction of the original fiber length,

d'"'"' is the diameter of the bundle after radial swelling, and

θ

is the wrap angle.

4. The membrane device of claim 3 wherein the device is adapted with inlet and outlet means for a shellside fluid.

5. The membrane device of claim 4 wherein the device is further comprised of end plates.

6. The membrane device of claim 5 wherein the core is a perforated tube.

7. The membrane device of claim 5 wherein the fiber bundle is wrapped in a spiral fashion about the core and passes through an aperture in the core to form a U-shaped configuration.

8. The membrane device of claim 5 wherein the device is comprised of two or more tubesheets.

9. The membrane device of claim 8 wherein the device is comprised of two or more fiber bundles.

10. The membrane device of claim 5 wherein the core is from about 15 to about 90 percent of the length of the hollow fibers.

11. The membrane device of claim 10 wherein each hollow fiber bundle contains between about 5 and 30,000 hollow fibers each.

12. The membrane device of claim 11 wherein the hollow fibers have a wall thickness of between about 20 and 200 microns.

13. The membrane device of claim 12 wherein the hollow fibers have an outer dimension of from about 100 to about 1000 microns.

14. The membrane device of claim 13 wherein the hollow fiber membranes are comprised of carboxy methyl cellulose;

polyvinyl alcohol;

sulfonated polyurea and salts thereof;

aromatic polyamide;

natural or synthetic rubbers including butyl or silicone rubber;

or a perfluorosulfonic acid polymer or metal salt thereof.

15. The membrane device of claim 14 wherein the membrane is comprised of a polymer of perfluorosulfonic acid or metal salt thereof and is comprised of units which correspond to the formula ##STR3## wherein R¹ is independently in each occurrence fluorine or a C_1-10 perfluoroalkyl group;

R² is independently in each occurrence fluorine or a C_1-10 perfluoroalkyl group;

X is hydrogen or a metal;

z is an integer of from about 0 to about 6;

m is a positive real number of from about 5 to about 15;

p is an integer of from about 0 to about 16; and

q is an integer of from about 1 to about 16.

16. The membrane device of claim 15 wherein the tubesheet is comprised of a polyglycidyl ether of a polyhydric phenol, or resin thereof, and a curing agent.