Abstract: A high efficiency natural draft gas burner that uses a plate attached to the burner tube to block secondary air from being introduced into a firetube or confined space vessel, ensuring that only inspired air nearly homogenously mixed with fuel is ignited at the burner tip. The venturi may be sized and shaped to ensure proper mixing of the inspired air and fuel, thus reducing emissions. This proper mixing combined with the lack of secondary air may reduce the fuel consumption and CO2 emissions of the burner by as much as 75%.

Abstract: A quench system for cooling hot flue gases from combustion systems is disclosed. The quench system includes a venturi mounted in a quench vessel. The water level in the quench vessel may be raised or lowered in accordance with the flow rate of the gases to be quenched. When the pressure drop across the venturi is insufficient to achieve the desired cooling to adiabatic saturation temperature, the water level is increased so that the downcomer connected to the venturi is submerged and the additional pressure drop further cools the flue gases.

Abstract: An improved radiant gas burner which includes a refractory burner tile hag an elongated passageway extending therethrough and a fuel-air mixture burner tube disposed within the passageway. The burner tube is of a one-piece elongated construction, includes a nozzle portion at the interior end of the passageway and is connected to means for introducing fuel gas and air therein by a threaded connection positioned adjacent the exterior end of the passageway. Secondary fuel is discharged from the passageway at a location adjacent the nozzle portion of the burner tube. An improved method of burning fuel gas and air using a radiant gas burner is also provided.