Atmospheric gas burner having extended turndown

Abstract

An atmospheric gas burner produces improved turndown by separating a small number of the burner ports for simmer service. The burner has an internal baffle which includes a cup section having four outwardly-extending channels. Each one of the channels aligns with a separate one of the ports. The burner also includes a first fuel nozzle arranged to provide fuel to all of the ports in conventional fashion and a second fuel nozzle which provides fuel to the four simmer ports only. The second fuel nozzle has an injection orifice with a smaller cross-sectional area than the injection orifice of the first fuel nozzle. Preferably, the second orifice is sized to provide the same input rate at a maximum pressure that the first orifice does at a minimum pressure. By using a small number of ports for simmer service, the gas velocity through these ports is increased and improved turndown is achieved. In another embodiment, the baffle divides each port into upper lower sections, instead of separating some of the ports. The upper section of each port comprises approximately one-sixth to one-fourth of the total port area and is used for simmer service.

Dependencies are inferred from the claim text.