Apparatus for recovering waste heat from exhaust gas flowing through an exhaust pipe

An assembly for mounting about a duct of arcuate cross-section adapted to transport hot waste combustion gases, for recovering waste heat therefrom, comprising:

• a. a plurality of thermal conduction members formed of solid extruded metal mounted side by side circumferentially around said duct, each of said thermal conduction members mounted longitudinally along said duct and having:
• (1) a longitudinal surface which is transversely concavely arcuate and of substantially the same curvature in cross-section as that of said duct and adapted to be positioned in engagement with the surface of said duct,
• (2) a longitudinal channel opposite said concavely arcuate surface having a bottom which is concavely arcuate in cross-section and having a pair of spaced-apart lateral fins,
• b. a plurality of water pipes each having an outer surface of substantially the same curvature in cross-section of the bottoms of the channels of said thermal conduction members, one water pipe being disposed in the bottom of each of the said channels, in close contact engagement with the bottoms of said channels, the fins of each thermal conduction member being crimped over the water pipe contained therein and in contact engagement with substantially the entire surface thereof, and tightly securing said water pipe to said thermal conduction member,
• c. a plurality of U-shaped pipes connecting the ends of adjacent water pipes to provide a single continuous water conduit, said water conduit having means at one end adapted to be connected to a water source, and means at the other end adapted to be connected to the water inlet of said water heater.