Gas-fired furnace

Claim 1

A gas-fired furnace comprising: a. a furnace housing having an air inlet and an air outlet; b. said furnace housing including a heat exchanger and a gasfired burner assembly, said burner assembly having a central opening therein and including a burner housing, fuel and air inlet means, and an outlet, said housing defining a plenum therein, a chamber of serrated cross-section configuration adapted to be received within said housing, said chamber having a plurality of generally V-shaped pockets therein, each pocket being defined by each serration, a gas ring manifold adapted to be received within said housing, said manifold having an inlet in communication with said fuel inlet means in said housing and a plurality of apertures spaced in axial alignment with said pockets of said serrated configured chamber whereby fuel enters said chamber through said pockets parallel to the axis of said chamber and, each V-shaped pocket includes two flanks, at least one of said flanks having at least one aperture therein whereby air entering said plenum through said air inlet in said housing passes through said aperture in said flank transversely of said fuel passing through said V-shaped pocket; c. said heat exchanger including a burner tube or relatively large cross-sectional area and being adapted to receive heated gas from said burner assembly, said burner tube having an inlet and an outlet and being in axial alignment with and in communication with said opening of said burner assembly at said inlet and a rear tube sheet at said outlet, said rear tube sheet having an opening therein of generally the same crosssectional area as the inside of said buRner tube communicating with said burner tube outlet, at least one second opening in the rear tube sheet communicating with flue gas return means being in communication with a flue gas collector, said flue gas return means being adapted to receive heated gas from said burner tube at said rear tube sheet and transferring said flue gas to said flue gas collector; d. said flue gas collector having a flue gas outlet; e. a combustion air inlet, and a fuel gas inlet, said combustion air inlet and said fuel gas inlet being in communicative relationship with said gas burner assembly; and, f. expansion means in communication with said burner tube whereby upon contraction and expansion of said burner tube said openings in said burner tube remain generally stationary.