14 described above. “Withdrawn toward the central portion of the humidifying membrane 13” means that, as shown in FIG. 4, the humidifying membrane 13 is exposed around the outer edge portion 14E of the protective film 14 when the protective film 14 provided so as to be stacked on the humidifying membrane 13 is viewed in plan. At this time, the outer peripheral length of the outer edge portion 14E of the protective film 14 is smaller than the outer peripheral length of the outer edge portion 13E of the humidifying membrane 13. In the present embodiment, the exposed portion of the humidifying membrane 13 between the outer edge portion 13E of the humidifying membrane 13 and the outer edge portion 14E of the protective film 14 is referred to as “close contact region 19.” In the present embodiment, the protective film 14 is provided on both the first surface 13A and the second surface 13B of the humidifying membrane 13, as described above. Of the protective films 14 provided on both the first surface 13A and the second surface 13B of the humidifying membrane 13, the protective film 14 on the second surface 13B is provided so as to be withdrawn toward the central portion of the humidifying membrane 13. On the other hand, the protective film 14 on the first surface 13A of the humidifying membrane 13 is provided in such a manner that the outer edge portion 14E of the protective film 14 is not withdrawn toward the central portion of the humidifying membrane 13 with respect to the outer edge portion 13E of the humidifying membrane 13. In the present embodiment, the protective film 14 on the first surface 13A of the humidifying membrane 13 is provided in such a manner that the outer edge portion 14E is aligned with the outer edge portion 13E of the humidifying membrane 13. The protective film 14 may protrude beyond the outer edge portion 13E of the humidifying membrane 13, as necessary.

The sealing material 15 is provided along the outer edge portion 13E of the humidifying membrane 13 in such a manner that the sealing material 15 sandwiches the humidifying membrane 13 and the protective films 14. Specifically, the sealing material 15 is provided on the outer peripheral portion of the one surface (front surface 11A) of the first separator 11 except for the dry gas supply path 51 and the humidified air discharge path 52 for the dry gas channels 11C, and is also provided on the outer peripheral portion of the one surface (front surface 12A) of the second separator 12 other than the water-containing gas supply path 61 and a water-containing air discharge path 62 for the water-containing gas channels 12C. In the present embodiment, “sandwich the humidifying membrane 13 and the protective films 14” refers to the state in which the sealing material 15 is located between the protective film 14 and the first separator 11 and between the protective film 14 and the second separator 12 so that the humidifying membrane 13 and the protective films 14 are separated from the outer peripheral portion of the first separator 11 and the outer peripheral portion of the second separator 12. The supply port 71 for the dry gas channels 11C in the outer peripheral portion of the one surface of the first separator 11 is a port that communicates with the dry gas supply path 51 and through which the dry gas is supplied to the dry gas channels 11C, and a discharge port 72 in the outer peripheral portion of the one surface of the first separator 11 is a port that communicates with the humidified air discharge path 52 and through which the humidified air is discharged from the dry gas channels 11C. The supply port 81 for the water-containing gas channels 12C in the outer peripheral portion of the one surface of the second separator 12 is a port that communicates with the water-containing gas supply path 61 and through which the water-containing gas is supplied to the water-containing gas channels 12C, and a discharge port 82 in the outer peripheral portion of the one surface of the second separator 12 is a port that communicates with the water-containing air discharge path 62 and through which the water-containing air is discharged from the water-containing gas channels 12C.

In the present embodiment, the sealing material 15 is provided in the entire periphery other than the dry gas supply path 51, the humidified air discharge path 52, the water-containing gas supply path 61, and the water-containing air discharge path 62 in such a manner that the humidifying membrane 13 and the protective films 14 are separated from the first separator 11 and the second separator 12. The sealing material 15 is shown in gray in FIG. 2. As shown in FIG. 3, the sealing material 15 is provided such that its outer edge is flush with the outer edges of the first separator 11 and the second separator 12. In FIG. 2, the outer edge of the sealing material 15 is shown located slightly inward of the outer edges of the first separator 11 and the second separator 12. However, the outer edge of the sealing material 15 actually is flush with the outer edges of the first separator 11 and the second separator 12. For example, an adhesive can be used as such a sealing material 15.

The sealing material 15 is provided so as to be in direct contact with the humidifying membrane 13 in the close contact region 19 of the humidifying membrane 13 between the outer edge portion 13E of the humidifying membrane 13 and the outer edge portion 14E of the protective film 14. Accordingly, even if the protective film 14 has voids in the thickness direction of the protective film 14, airtightness between the sealing material and the humidifying membrane 13 is improved and sealing is provided between the dry gas channels 11C and the water-containing gas channels 12C, so that the risk of leakage (cross leakage) of air (dry air and humidified air) from the dry gas channels 11C to the water-containing gas channels 12C can be reduced.

The close contact region 19 of the humidifying membrane 13 is provided on at least either the first surface 13A that is the front surface of the humidifying membrane 13 and the second surface 13B that is the back surface of the humidifying membrane 13. In the present embodiment, the protective film 14 is provided on both the first surface 13A and the second surface 13B of the humidifying membrane 13, but the close contact region 19 is provided only on the second surface 13B. Normally, the dry air flowing through the dry gas channels 11C has been compressed by the compressor 41, and therefore has a higher pressure than the water-containing air flowing through the water-containing gas channels 12C. Accordingly, providing the close contact region 19 on the second surface 13B that is subjected to the pressure of the dry air is suitable because the humidifying membrane 13 is less likely to be bent and deformed even when there is a pressure difference between the dry air (high pressure) flowing through the dry gas channels 11C and the water-containing air (low pressure) flowing through the water-containing gas channels 12C. It should be understood that the close contact region 19 may be provided on both the first surface 13A and the second surface 13B, or may be provided only on the first surface 13A. Moreover, in the case where the protective film 14 is provided on only either the first surface 13A or the second surface 13B of the humidifying membrane 13, and the outer edge portion 14E of the protective film 14 placed on only one surface of the humidifying membrane 13 is aligned with, or protrudes beyond, the outer edge portion 13E of the humidifying membrane 13, the close contact region 19 may be provided on the opposite surface of the humidifying membrane 13 from the surface on which the protective film 14 is provided.

FIG. 4 shows in plan the humidifying membrane 13 and the protective film 14 provided on the second surface 13B of the humidifying membrane 13 in such a manner that the outer edge portion 14E is withdrawn toward the central portion of the humidifying membrane 13 with respect to the outer edge portion 13E of the humidifying membrane 13. In the present embodiment, the humidifying membrane 13 and the protective film 14 provided in the withdrawn state are configured to have a plurality of (in the present embodiment, four) portions that are parallel to each other. In FIG. 4, such parallel portions are denoted by sign P. The distance between the outer edge portion 13E of the humidifying membrane 13 and the outer edge portion 14E of the protective film 14 as viewed in plan (width of the close contact region 19) can thus be made equal in the plurality of parallel portions P. The supply port 71, the discharge port 72, the supply port 81, and the discharge port 82 are formed in the corners of the humidifying membrane 13 and the protective film 14 that are portions that are not parallel (not denoted by sign P) (see also FIG. 2). The distance between the outer edge portion 13E of the humidifying membrane 13 and the outer edge portion 14E of the protective film 14 provided with the sealing material 15 as viewed in plan (width of the close contact region 19) is the same in the entire periphery. Therefore, even if the humidifying membrane 13 expands or contracts due to change in external environment, the protective film 14 can follow such expansion or contraction, so that damage to (e.g., breakage of) the protective film 14 and the humidifying membrane 13 can be prevented. Since the sealing material 15 is uniformly in close contact with the humidifying membrane 13 and the protective film 14 in the entire periphery, the humidifying membrane 13 and the protective film 14 are less likely to wrinkle.

Moreover, in the present embodiment, as shown in FIGS. 4 and 5, at least corners 13R of the outer edge portion 13E of the humidifying membrane 13 are formed in a circular arc shape as viewed in plan. When part of the corners 13R of the outer edge portion 13E of the humidifying membrane 13 does not overlap the supply port 71, the discharge port 72, the supply port 81, and the discharge port 82, or when the supply port 71, the discharge port 72, the supply port 81, and the discharge port 82 are formed in portions other than the corners 13R (portions denoted by sign P), the sealing material 15 can be more easily provided on the corners 13R. Therefore, it is preferable that the distance between the outer edge portion 13E of the humidifying membrane 13 and the outer edge portion 14E of the protective film 14 (width of the close contact region 19) be the same in the corners 13R as well. That is, it is preferable to form the protective film 14 in a rectangular shape so that the centers O of the circular arcs of the corners 13R of the humidifying membrane 13 are located at the vertexes of the protective film 14 (see FIG. 5), or to form corners 14R of the outer edge portion 14E of the protective film 14 in a circular arc shape so that the centers O of the corners 13R of the humidifying membrane 13 match the centers O of the corners 14R of the protective film 14 (see FIG. 4). With this configuration, the width of the close contact region 19 where the humidifying membrane 13 is exposed (distance between the outer edge portion 13E of the humidifying membrane 13 and the outer edge portion 14E of the protective film 14) when the protective film 14 provided so as to be stacked on the humidifying membrane 13 is viewed in plan can be made equal in the entire periphery of the humidifying membrane 13 and the protective film 14 including the supply port 71, the discharge port 72, the supply port 81, and the discharge port 82 (not shown in FIG. 4).

Second Embodiment

Next, the humidifier 1 according to a second embodiment will be described. In the description of the present embodiment, the portions having the same configuration as in the first embodiment are denoted by the same signs as in the first embodiment, and description of the same configuration will be omitted. The humidifier 1 according to the present embodiment is different from the first embodiment in the configuration of the humidifying unit 10.

As shown in FIG. 6, in the present embodiment, a reinforcing member 16 is provided between the second separator 12 and the protective film 14 provided on the first surface 13A of the humidifying membrane 13. That is, the reinforcing member 16 is stacked on the opposite side from the humidifying membrane 13 so as to face the protective film 14 provided on the first surface 13A of the humidifying membrane 13. The reinforcing member 16 and the protective film 14 are disposed in contact with each other. In the present embodiment, the reinforcing member 16 has the same size as the humidifying membrane 13 and the protective film 14 facing (adjacent to) the reinforcing member 16. On the other hand, the protective film 14 on the second surface 13B of the humidifying membrane 13 is provided so as to be withdrawn toward the central portion of the humidifying membrane 13, so that the humidifying membrane 13 has the close contact region 19 only on the second surface 13B. For example, resin mesh is used as the reinforcing member 16. However, the reinforcing member 16 is not limited to this, and paper, nonwoven fabric, a porous film, etc. can be used. In the present embodiment, the protective film 14 and the reinforcing member 16 are entirely in contact with each other. However, the protective film 14 and the reinforcing member 16 may be configured to be only partially in contact with each other, for example, only in their central regions.

The sealing material 15 is provided along the outer edge portion 13E of the humidifying membrane 13 in such a manner that the sealing material