Abstract: An improved air-to-air, heat-and-moisture exchanger is described which facilitates the simultaneous transfer of both heat and water vapor between two streams of air while greatly inhibiting the transfer of pollutant gases. A rigid encasement supports a stack of flat, thin-film composite membranes that are held in parallel, spaced-apart relation, thereby forming a box-shaped exchanger. The membranes are synthesized by interfacial polymerization, a process whereby a thin, non-porous film may be uniformly deposited onto a porous substrate material. The thin film is hydrophilic so as to provide high water vapor flux together with excellent selectivity against the transfer of other gases and vapors. The substrate provides mechanical support.

Abstract: A heat exchanger for fluids such as liquids, steam, gases, etc. comprises a tank (10) with two separated closed systems for the fluids, between which heat is to be exchanged.The tank (10) has an insert (18)consisting of longitudinally curved, preferably semicircularly shaped elements (12). The elements (12) are assembled in a sequence with their concave surfaces contacting the edges of the adjoining element. Along said edges the elements are assembled fluidtight. Between two elements (12), thus, a channel (16) is formed open to two opposite sides of the insert (18). The inlet and outlet means (20) are respectively connected to these sides, so that every second fluid channel (16) is connected to the same inlet and outlet means (20) respectively, the fluid thus being adapted to be supplied to every second channel from the corresponding inlet and outlet means.

Abstract: The present invention relates to a core assembly for use in an air-to-air heat exchanger. The core is comprised of a plurality of square plates. Each plate is comprised of a square planar central region; a first pair of opposed edge flanges bent in a first direction with respect to the central region to form approximately 90 degree angle with the central region; and a second pair of opposed edge flanges bent in a direction opposite the first direction with respect to the central region to form approximately 90 degree angle with the central region. The core is formed by the plurality of square plates that are positioned into a stack of parallel plates such that the opposed flanges of one of the plurality of plates is located in contact with and inside mating opposed flanges of a plate directly adjacent thereto, thereby forming a plurality of air passages between adjacent plates such that two perpendicular air pathways are formed in an interleaved orientation.