Burner for low profile impingement oven

A food preparation apparatus including a cooking chamber (12) having a pair of openings (22,24) in two opposite facing walls (26,27) thereof. A conveyor extends through the side wall openings (22,24) in the chamber (12) for conveying a food product through the chamber (12). First and second pairs of impingement finger ducts (32A,34A,32B,34B) are provided for forming a plurality of columnated air jets and for impinging the jets against discreet points of a food product supported on the conveyor (30). A first one (32A,32B) of each of said pairs of finger ducts is disposed above the conveyor (30) and a second one (34A,34B) of each of said pairs of finger ducts (32,34) is disposed below the conveyor (30). First and second plenums (48A,48B), each of which has a fan (46A,46B) respectively associated therewith, supply air to the finger ducts (32,34). A single burner (70) is associated with the plenums (48) for simultaneously supplying thermal energy to both plenums (48A,48B). The burner (70) includes a first adjustable baffle (96) for apportioning the thermal energy between the two plenums (48A,48B). The burner (70) includes a second baffle (102) located in the return air stream forwardly of the burner flame to generate a negative pressure zone and draw the flame forwardly, away from the back wall of the burner (42).