Abstract: Disclosed is a gas-fired oven for heating food by steam and/or dry convection. The oven has a heating chamber; an atomizer for producing an atomized water spray; a source of a combustible gas mixture; and a burner-heat exchanger. The gas fired burner-heat exchanger receives and combusts the mixture and isolates hot combustion gases from the heating chamber so pure steam is furnished to the heating chamber. The heat exchanger receives hot combustion gases, and vaporizes atomized spray circulated over its external surface to produce steam for heating an article in the heating chamber. The amount of steam in the heating chamber is measured and controlled by monitoring a temperature in a drain.

Abstract: Infrared (IR) strip heaters are juxtaposed with convection heaters for simultaneous, independently controlled, combined radiant/convective heating in a conveyor oven. Apertured plates with portions transmissive to IR radiation are interposed between a lower combined heating unit and the cooking path. The IR heaters are preferably gas burners with porous, ceramic or metallic elements, the burners on opposite sides of the cooking path being independently controllable to vary the heat transfer rate to opposite food surfaces. Symmetrical placement of the IR heaters in opposed pairs facilitates use of the conveyor oven as a half oven. An auxiliary burner exhausts directly into the convection air and is cycled on and off to maintain a set temperature during normal operation.