Separator including an elastic layer for use in humidifying device, humidifying device, and fuel cell system including humidifying device

1. A separator for use in a humidifying device comprising:

an elastic layer including a convex-concave portion formed on each of main surfaces of said elastic layer,

wherein convex portions of the convex-concave portion contact a steam permeable membrane, and

a fluid channel is formed by concave portions of the convex-concave portion.

2. The separator according to claim 1 , wherein a thickness of the elastic layer is not less than 1.66 times as large as a thickness of the steam permeable membrane.

3. The separator according to claim 1 , further comprising a stiff layer.

4. The separator according to claim 3 , wherein:

wall portions formed by the elastic layer are formed to project from a surface of the stiff layer;

the wall portions constitute the convex portions of the convex-concave portion; and

spaces between the wall portions constitute the concave portions of the convex-concave portion.

5. The separator according to claim 1 , wherein the convex portions are entirely constituted by the elastic layer.

6. The separator according to claim 3 , wherein the elastic layer comprises:

a first elastic layer; and

a second elastic layer, wherein:

the first elastic layer and the second elastic layer are connected to each other by through holes formed on the stiff layer.

7. The separator according to claim 1 , being entirely formed by the elastic layer.

8. The separator according to claim 1 , wherein the elastic layer is formed to contain EPDM or fluorocarbon rubber not containing sulfur.

9. The separator according to claim 1 , wherein the elastic layer has hardness of 30 to 100 of A Scale of Durometer Hardness defined in JIS K6200.

10. A humidifying device comprising: separators according to any one of claims 1 to 7 ; and

steam permeable membranes, wherein:

the separators and the steam permeable membranes are stacked on and fastened to one another such that a steam permeable membrane is sandwiched between the main surfaces of the elastic layer; and

a primary fluid flows through a first channel formed on one of the main surfaces of each of the elastic layers which surface contacts the steam permeable membrane, and a secondary fluid flows through a second channel formed on the other main surface of each of the elastic layers which surface contacts the steam permeable membrane, causing moisture contained in the primary fluid to permeate the steam permeable membrane to humidify the secondary fluid.

11. A fuel cell system comprising: a fuel cell configured to generate electric power by using a fuel gas and an oxidizing gas; and

the humidifying device according to claim 10 , which is disposed on a supply channel of at least one of the fuel gas and the oxidizing gas.

12. The separator according to claim 1 , wherein the elastic layer includes an organic polymer.

13. The separator according to claim 1 , wherein the elastic layer includes at least one of an elastomer and plastic foam.