Abstract: An improved burner for combustion of fuel gas with air in a manner to result in low NOx, the burner is generally circular and has a refractory tile and gas tips. The gas tips are spaced around the outer circumference of a generally circular passageway in the burner tile, each gas tip is positioned to cause the fuel gas to entrain furnace flue gas. Each gas tip has one or more ports, an ignition port and at least one firing port. The ignition port injects fuel through a passageway to the burner tile. The firing port injects fuel gas in the direction that is generally upward with respect to the pathway of the ignition port. This causes fuel gas to entrain combustion products from the flue gas, the resulting mixture of fuel gas and flue gas is directed out of the burner tile to mix with combustion air that is discharged through the burner tile.

Abstract: A burner for combusting fuel gas and air in an enclosure having a burner block member of non-combustible material, such as ceramic, having a central rectangular or square opening. Said burner block being located between the surface to be heated and an enclosure wall opposite said surface, said central rectangular or square block opening being used to shape the combustion flame in a flat or fan shaped fashion parallel to the enclosure wall surface. In such an arrangement, the burner's purpose is to direct combustion flame upon the enclosure wall which is heated by the flame and radiates heat back towards the surface area to be heated and to reduce the oxygen content which serves to reduce the peak flame temperature of the combustion process to thereby reducing NO.sub.x production.

Abstract: A burner for combusting gas and/or liquid fuel and air in an enclosure includes a burner block of non-combustible material, such as ceramic material, having a central opening therethrough communicating with a combustion zone. The burner block has a plurality of spaced apart recirculation gas passageways paralleled to and spaced from the central opening, each of the recirculation gas passageways having an injection passageway communicating with the block member central opening. Fuel, which may be liquid and/or gas, is injected into said burner block central opening. Venturi action causes furnace gas to be drawn from the cool fringes of the combustion zone through the recirculation gas passageways for passage back into the central opening wherein air and fuel are thoroughly mixed and cooled for combustion within the enclosure. This recirculation system serves to reduce the temperature and oxygen content of the local combustion process to thereby reduce NO.sub.x production.

Abstract: A burner for combusting fuel gas and air in an enclosure includes a block member of non-combustible material, such as ceramic material, having a central opening therethrough. The block member has a plurality of spaced apart recirculation gas passageways paralleled to and spaced from the central opening, each of the recirculation gas passageways having an injection passageway communicating with the block member central opening. A fuel gas jet is positioned within each of the recirculation gas passageways for injecting fuel gas into the injection passageways to cause the injected fuel gas by Venturi action, to draw furnace gas from the cool fringes of the combustion zone through the recirculation gas passageways for passage back into the central opening after local combustion wherein modified air and fuel gas are thoroughly mixed and cooled for combustion within the enclosure. This recirculation system serves to reduce the temperature and oxygen content of the local combustion process to thereby reduce NO.sub.