Patent ID: 7258080
Filing Date: 2007-08-21
Classification: F24H,Y02B

Abstract:
1. An apparatus for heating a fluid, comprising: a first tank for holding a first quantity of a fluid to be heated; a second tank for holding a second quantity of the fluid to be heated, said second tank being spaced apart from said first tank in a first direction, one of said first and second tanks having a fluid receiving inlet, and the other of said first and second tanks having a fluid discharge outlet; a receiving plenum interposed between said first and second tanks; a fluid transfer conduit structure interconnected between said first and second tanks; a combustion chamber, said first tank being interposed between said combustion chamber and said receiving plenum; a spaced plurality of primary flue tubes longitudinally extending through said first tank in said first direction and interconnecting said combustion chamber and said receiving plenum; a secondary flue pipe having an inner longitudinal portion extending in said first direction from said receiving plenum through said second tank, an intermediate longitudinal portion coiling about said inner longitudinal portion in a second direction opposite from said first direction, and an outer longitudinal portion passing outwardly through said second tank; and a fuel burner operative during firing thereof to flow hot combustion gases sequentially through said combustion chamber, said primary flue tubes, said receiving plenum and said secondary flue pipe.