Patent ID: 6880544

Claim:
A rack oven comprising: a plurality of wall structures defining an oven interior; a door providing access to the oven interior; a baking chamber within the oven interior; a passive steam generator within the oven interior, the steam generator including a plurality of stacks of laterally extending elongated members, the stacks being arranged one directly above the next, each stack having a first number of lower elongated members, the first number being at least one, a second number of middle elongated members positioned above the lower elongated members with the second number being larger than the first number, and a third number of upper elongated members positioned above the middle elongated members with the third number being larger than the second number, the upper, middle and lower elongated members of each stack being arranged such that water applied to the upper elongated members of the stack falls downward with at least a portion thereof falling onto the middle elongated members of the stack and then falling onto the lower elongated members of the stack, and then falls downward onto the upper elongated members of the stack therebelow; a source of water supplying water to an upper stack of the plurality of stacks, a heat exchanger within the oven interior, the heat exchanger comprising a burner chamber, an undivided exhaust collection plenum positioned above the burner chamber, and a plurality of straight heat exchange tubes extending upwardly between and communicating with the burner chamber and the collection plenum; a plurality of gas burners positioned within the burner chamber; a flue communicating with the collection plenum to exhaust combustion gases from the collection plenum to exterior of the oven interior; and a blower arranged to circulate air within the oven interior among the heat exchange tubes, the steam generator and the baking chamber, the steam generator being configured and positioned to produce steam using the circulating air heated by the heat exchange tubes and provide the steam to the circulating air for delivery to the baking chamber.