F28D 7/087

Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being otherwise bent, e.g. in a serpentine or zig-zag {with serpentine or zig-zag configuration in the form of parallel conduits coupled by bent portions assembled in arrays, each array being arranged in the same plane}