Abstract: A highly efficient parallel flow evaporator is provided by combining a pair of identical units (10), (12) wherein each includes a pair of identical, parallel, spaced headers (40) each having slots (44) receiving the ends of identical flattened tubes (22). Identical tanks (42) are bonded to each of the headers (40) and each has an identical central flat surface (52) and an identical, centrally located port (60). Fins (26) extend between adjacent tubes (22) in each unit (10), (12) and an inlet/outlet fixture (32) is bonded to the flat surfaces (52) of one pair of tanks (42) defined by adjacent tanks (42) of both of the units (10),(12). A cross-over fixture (30) is bonded to the flat surfaces (52) of the other pair of tanks (42) defined by the remaining tanks (42) of both of the units (10),(12).

Abstract: An internally finned multiple piece tube for use in a heat exchanger including an elongated fin 28, a first, elongated, C-shaped channel 24 having a first base 34 and spaced first legs 36, and a second, elongated C-shaped channel 26 having a second base 38 and spaced second legs 40. The fin 28 and the second channel 26 are nested in the first channel 24 between the first legs 36 thereof such that the fin 28 is sandwiched between and engaged by both the first and second bases 34 and 38 with the first legs 36 extending around and behind the second legs 40 to hold the tube 20 in assembled relation.

Abstract: An improved turbulator and conduit structure for use in heat exchangers. An elongated tube through which fluid to be subject to a heat exchange process is provided with a first outer winding within the tube in substantial abutment with the inner wall of the tube and a second inner winding at least partially within the first winding. The pitch of the first winding is different from the pitch of the second winding. Consistent heat exchange at extremely low Reynolds numberes is obtainable with the structure. Also disclosed is a method of making such a turbulator and conduit structure.

Abstract: A heat transfer device comprising in one embodiment concentric tubes with spaced surfaces to define a fluid flow space through which a heat transfer fluid is directed and with this space being spanned by a series of fins extending between the tubes with at least one of the tubes being provided with spaced contact members extending toward the other tube and engaging the fins compressively to provide snug heat transfer contact between the boundary members or tubes and the fins so as to compensate for variations in the dimensions in one or both of the tubes and fins.

Abstract: A connection for securing a tank to a header plate in a heat exchanger. A metal header plate is provided with a peripheral groove having a bottom wall and an upstanding side wall. A compressible gasket is received in the groove in a plastic tank as a flange disposed in the groove to compress the gasket. A plurality of tabs are deformed from the side wall to overlie a side of the flange and the side wall bent toward the tank. The tabs are generally egg-shaped or spherical and have free edges engaging the flange to provide excellent resistance to deformation.