Assymetric hollow fiber heat exchangers

Abstract

A method of making an asymmetric polymeric hollow fiber includes dissolving a polymer in one or more solvents to form a polymer solution, providing the polymer solution to a spinneret or device in which a bore fluid is directed to flow through a first tube surrounded by a larger, second tube through which the polymer solution flows, and co-extruding the polymer solution and bore fluid. The method forms a first, substantially impermeable portion of the asymmetric polymeric hollow fiber and second, porous portion of the asymmetric polymeric hollow fiber.

1 . A method of making an asymmetric polymeric hollow fiber comprising:
 dissolving a polymer in one or more solvents to form a polymer solution;   providing the polymer solution to a spinneret or device in which a bore fluid is directed to flow through a first tube surrounded by a larger, second tube through which the polymer solution flows;   co-extruding the polymer solution and bore fluid;   forming a first, substantially impermeable portion of the asymmetric polymeric hollow fiber; and   forming a second, porous portion of the asymmetric polymeric hollow fiber.   
     
     
         2 . The method of  claim 1 , wherein the substantially impermeable portion comprises a polymer skin layer of a polymer fiber formed by evaporating a portion of the one or more solvents. 
     
     
         3 . The method of  claim 3 , wherein the porous portion is formed by directing the polymer fiber to a precipitation fluid, the precipitation fluid extracting solvent from an inner portion of the polymer fiber. 
     
     
         4 . The method of  claim 1 , wherein the substantially impermeable portion is formed by reaction in the precipitation fluid. 
     
     
         5 . The method of  claim 1 , further comprising pretreating the polymer prior to dissolving the polymer to enhance the solubility of the polymer in the one or more solvents. 
     
     
         6 - 11 . (canceled) 
     
     
         12 . The method of  claim 1 , further comprising post-treating the asymmetric polymeric hollow fiber after forming the porous portion to increase cross-linking of the asymmetric polymeric hollow fiber by heating, exposure to UV light, or chemical treatment with acid, base or reagent. 
     
     
         13 - 16 . (canceled) 
     
     
         17 . The method of  claim 1 , further comprising exposing the asymmetric polymeric hollow fiber to a substance which forms a solid deposit within pores of the porous inner polymer layer. 
     
     
         18 - 23 . (canceled) 
     
     
         24 . The method of  claim 1 , wherein the first, substantially impermeable portion is located on an outside surface of the asymmetric polymeric hollow fiber, the second substantially impermeable portion is located on an inside surface of the asymmetric polymeric hollow fiber and the porous portion is located between the outside and inside surfaces of the asymmetric polymeric hollow fiber. 
     
     
         25 . A method of making heat transfer device comprising the asymmetric polymeric hollow fibers of  claim 1 , comprising:
 cutting the asymmetric polymeric hollow fibers into predetermined lengths, each fiber having a first end and an opposite second end;   mounting the first ends in a first mount and the second ends in second mount; and   removing portions of the first and second mounts, thereby exposing openings of the asymmetric polymeric hollow fibers.   
     
     
         26 - 29 . (canceled) 
     
     
         30 . A method of using an asymmetric polymeric hollow fiber device having at least one asymmetric polymeric hollow fiber comprising an impermeable surface and an opposite porous surface, the method comprising:
 providing a first fluid having a first temperature to an inner surface of a wall of the asymmetric polymeric hollow fiber;   providing a second fluid having a second temperature to an outer surface of the wall of the asymmetric polymeric hollow fiber, wherein the second temperature is different from the first temperature; and   transferring heat from the first fluid to the second fluid or the second fluid to the first fluid through the wall of the asymmetric polymeric hollow fiber.   
     
     
         31 . The method of  claim 30 , further comprising providing a third fluid, the third fluid configured to transfer at least one of mass or heat to or from the first fluid. 
     
     
         32 . The method of  claim 31 , further comprising providing a fourth fluid, the fourth fluid configured to transfer at least one of mass or heat to or from the second fluid. 
     
     
         33 . The method of  claim 30 , wherein at least one of the inner surface and the outer surface comprise a hydrophilic coating or a hydrophobic coating. 
     
     
         34 . An asymmetric polymeric hollow fiber comprising:
 a first, substantially impermeable portion; and   second, porous portion.   
     
     
         35 . The fiber of  claim 34 , wherein the impermeable portion comprises an outer skin of the fiber. 
     
     
         36 . The fiber of  claim 35 , further comprising a second impermeable portion comprising an inner skin of the fiber, the second porous portion located between the first and second impermeable portions. 
     
     
         37 . The fiber of  claim 36 , further comprising a solid deposit located in pores of the porous portion. 
     
     
         38 . The fiber of  claim 37 , wherein the asymmetric polymeric hollow fiber comprises an inner surface and an outer surface and at least one of the inner surface and the outer surface comprise a hydrophilic coating or a hydrophobic coating. 
     
     
         39 . An asymmetric polymeric hollow fiber device comprising a plurality of asymmetric polymeric hollow fibers of  claim 34 . 
     
     
         40 - 43 . (canceled)