Patent ID: 8919746

Claim:
A humidifier for transferring water vapour from a first gas stream to a second gas stream, the humidifier comprising: (a) a plurality of plates arranged in a stack, each of said plates defining a gas flow passage for either said first gas stream or said second gas stream, wherein each of said plates comprises: (i) a top, a bottom and a thickness measured between said top and bottom; (ii) an inlet opening along an edge of the plate; (iii) an outlet opening along an edge of the plate; (iv) a flow field defined in a central portion of the plate, the flow field having an open top along the top of the plate and an open bottom along the bottom of the plate; (v) an inlet passage connecting said inlet opening to the open top and the open bottom of said flow field; (vi) an outlet passage connecting the open top and the open bottom of said flow field to said outlet opening; (vii) a planar top sealing surface extending along the top of the plate, wherein the top sealing surface extends continuously around the flow field, and includes bridging portions extending across the inlet passage and the outlet passage; (viii) a planar bottom sealing surface extending along the bottom of the plate, wherein the bottom sealing surface extends continuously around the flow field, and includes bridging portions extending across the inlet passage and the outlet passage; (ix) a plurality of support structures located within the flow field and extending between the top and bottom of the plate; wherein pairs of said plates are sealed together in said stack with the top sealing surface of one plate sealed to the bottom sealing surface of an adjacent plate; (b) a plurality of water permeable membranes, wherein one of said membranes is provided between each pair of adjacent plates in said stack, and is sealed to said pair of adjacent plates, and wherein said support structures provide support for said water permeable membranes within the flow fields; (c) a pair of manifolds for said first gas stream, and a pair of manifolds for said second gas stream, wherein a first pair of said manifolds is in flow communication with a first plurality of said plates defining said gas flow passages for said first gas stream, and wherein a second pair of said manifolds is in flow communication with a second plurality of said plates defining said gas flow passages for said second gas stream, wherein said plates are stacked and said manifolds are arranged such that the gas flow passages for said first gas stream alternate with the gas flow passages for said second gas stream throughout said stack, and such that each of the water permeable membranes separates one of the gas flow passages for the first gas stream from one of the gas flow passages for the second gas stream; and wherein the top and bottom sealing surfaces of the plates, including the bridging portions, are provided with a compressible sealing material.