Abstract: A heat exchanger including a header having a plurality of header openings with conduits that may be made of plastic are inserted in the openings. The conduits are sealed to the header to prevent leakage between the header and the tubes to prevent water and air leakage between the wet, scavenger air stream flowing through the tubes and a dry air stream flowing around the tubes. A method of making the heat exchanger includes providing the openings inwardly curving perimeter walls that allow for easy insertion of the tubes. A self-leveling sealant may be used to seal the heat exchange conduits to the header using, for example, a paint roller and/or a paint sprayer. The heat exchange conduits can include a plurality of stubby fins formed on the inner wall surface of the conduit.

Abstract: A heat exchanger is provided that includes an expansion joint that accommodates thermal expansion of an inner casing relative to an outer casing. The expansion joint is positioned between the inner casing and the outer casing and is shielded from high temperature fluid flows by a wall of the heat exchanger and by thermal insulation.

Abstract: A desiccant dehumidifier is provided in which a desiccant material is applied to a first end of a heat pipe heat exchanger. During the sorption phase, a supply air stream is exposed to the desiccant material on the first end of the heat pipe heat exchanger and a second air stream, which could be ambient atmosphere, is exposed to the second end of the heat pipe heat exchanger. The moisture from the supply air stream is transferred to the desiccant material. However, the heat pipe heat exchanger acts as a heat sink and adsorbs the heat generated by the moisture transfer and transfers it to the second end of the heat pipe heat exchanger. At the second end of the heat pipe heat exchanger, the heat is transferred to the second air stream. As a result, both the supply air stream and the desiccant material remain at a substantially constant temperature during the sorption phase.

Abstract: A plate type heat exchanger of the continuous plate type includes a housing having opposed open ends and a thermal transfer core disposed within the housing which is formed of a continuous sheet of heat conductive material folded upon itself on fold regions in opposite directions alternately to define a plurality of substantially parallel, mutually spaced sheet portions which extend through the housing, substantially each sheet portion thereby being located between first and second adjacent sheet portions with the fold regions being located contiguous with opposed sides of the housing.

Abstract: A heat exchanger core includes a communicating set of metallic tubular elements, preferably aluminum, for carrying a primary fluid and a matrix of rounded metallic elements. The matrix elements are metallurgically bonded to one another and to the tubular elements. This arrangement of the matrix creates a multiplicity of communicating interstices which serve as passageways for the secondary fluid. The surface of the rounded elements constitutes the major area exposed to the secondary fluid flow. The rounded elements are metallurgically bonded by preferably a brazing technique. Relatively small particles of low melting temperature alloy, preferably aluminum, are dispersed throughout a stacked arrangement of relatively larger rounded elements, preferably of aluminum of a higher melting temperature. In one brazing method, an assembly of tubes, large rounded elements and smaller particles are brazed in a vacuum brazing oven. At the temperature of the oven, the smaller particles melt but the larger elements do not.