Membrane contactor for dehumidification systems

1. A contactor configured for use in a dehumidification system comprising:

a plurality of contact modules contained within a single housing of the contactor, each contact module having a porous membrane that defines an internal space through which a hygroscopic material flows, wherein at least one of thermal conductivity and permeability of the porous membrane of at least one contact module is generally distinct from the remainder other membranes of the plurality of contact modules within the contactor.

2. The contactor according to claim 1 , wherein the porous membrane is permeable to water vapor and impermeable to the hygroscopic material.

3. The contactor according to claim 1 , wherein air is configured to flow through at least one channel formed between an exterior side of the porous membrane of adjacent contact modules.

4. The contactor according to claim 3 , wherein the air is configured to flow through the contactor in a single pass or multiple passes.

5. The contactor according to claim 3 , wherein the porous membrane of each of the plurality of contact modules has a generally different permeability.

6. The contactor according to claim 5 , wherein the permeability of the porous membrane of each of the plurality of contact modules incrementally varies along at least one dimension of the contactor.

7. The contactor according to claim 6 , where the permeability of the porous membrane of each of the plurality of contact modules incrementally varies in a direction of the flow of air.

8. The contactor according to claim 7 , wherein at least one contact module arranged adjacent an inlet end of the at least one channel has a porous membrane with a high permeability and at least one contact module arranged adjacent an outlet end of the at least one channel has a porous membrane with a low permeability.

9. The contactor according to claim 7 , wherein at least one contact module arranged adjacent an inlet end of the at least one channel has a porous membrane with a low permeability and at least one contact module arranged adjacent an outlet end of the at least one channel has a porous membrane with a high permeability.

10. The contactor according to claim 3 , wherein the porous membrane of at least one contact module is generally impermeable.

11. The contactor according to claim 10 , wherein the at least one contact module having a substantially impermeable porous membrane is arranged adjacent an outlet end of the at least one channel.

12. The contactor according to claim 10 , wherein the at least one contact module is formed from a conventional solid tube.

13. The contactor according to claim 10 , wherein the at least one contact module is formed from a planar porous membrane.

14. The contactor according to claim 3 , wherein the porous membrane of each of the plurality of contact modules has a substantially different thermal conductivity.

15. The contactor according to claim 14 , wherein the thermal conductivity of the porous membrane of each of the plurality of contact modules incrementally varies along at least one dimension of the contactor.

16. The contactor according to claim 15 , where the thermal conductivity of the porous membrane of each of the plurality of contact modules incrementally varies in a direction of the flow of air.

17. The contactor according to claim 16 , wherein at least one contact module arranged adjacent an inlet end of the at least one channel has a porous membrane with a low thermal conductivity and at least one contact module arranged adjacent an outlet end of the at least one channel has a porous membrane with a high thermal conductivity.

18. The contactor according to claim 3 , wherein the porous membrane of at least one contact module is substantially thermally unconductive.